diff options
Diffstat (limited to 'drivers/spi/spi.c')
| -rw-r--r-- | drivers/spi/spi.c | 4609 |
1 files changed, 4609 insertions, 0 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c new file mode 100644 index 000000000..19688f333 --- /dev/null +++ b/drivers/spi/spi.c @@ -0,0 +1,4609 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +// SPI init/core code +// +// Copyright (C) 2005 David Brownell +// Copyright (C) 2008 Secret Lab Technologies Ltd. + +#include <linux/kernel.h> +#include <linux/device.h> +#include <linux/init.h> +#include <linux/cache.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/mutex.h> +#include <linux/of_device.h> +#include <linux/of_irq.h> +#include <linux/clk/clk-conf.h> +#include <linux/slab.h> +#include <linux/mod_devicetable.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi-mem.h> +#include <linux/gpio/consumer.h> +#include <linux/pm_runtime.h> +#include <linux/pm_domain.h> +#include <linux/property.h> +#include <linux/export.h> +#include <linux/sched/rt.h> +#include <uapi/linux/sched/types.h> +#include <linux/delay.h> +#include <linux/kthread.h> +#include <linux/ioport.h> +#include <linux/acpi.h> +#include <linux/highmem.h> +#include <linux/idr.h> +#include <linux/platform_data/x86/apple.h> +#include <linux/ptp_clock_kernel.h> +#include <linux/percpu.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/spi.h> +EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start); +EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop); + +#include "internals.h" + +static DEFINE_IDR(spi_master_idr); + +static void spidev_release(struct device *dev) +{ + struct spi_device *spi = to_spi_device(dev); + + spi_controller_put(spi->controller); + kfree(spi->driver_override); + free_percpu(spi->pcpu_statistics); + kfree(spi); +} + +static ssize_t +modalias_show(struct device *dev, struct device_attribute *a, char *buf) +{ + const struct spi_device *spi = to_spi_device(dev); + int len; + + len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); + if (len != -ENODEV) + return len; + + return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias); +} +static DEVICE_ATTR_RO(modalias); + +static ssize_t driver_override_store(struct device *dev, + struct device_attribute *a, + const char *buf, size_t count) +{ + struct spi_device *spi = to_spi_device(dev); + int ret; + + ret = driver_set_override(dev, &spi->driver_override, buf, count); + if (ret) + return ret; + + return count; +} + +static ssize_t driver_override_show(struct device *dev, + struct device_attribute *a, char *buf) +{ + const struct spi_device *spi = to_spi_device(dev); + ssize_t len; + + device_lock(dev); + len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : ""); + device_unlock(dev); + return len; +} +static DEVICE_ATTR_RW(driver_override); + +static struct spi_statistics __percpu *spi_alloc_pcpu_stats(struct device *dev) +{ + struct spi_statistics __percpu *pcpu_stats; + + if (dev) + pcpu_stats = devm_alloc_percpu(dev, struct spi_statistics); + else + pcpu_stats = alloc_percpu_gfp(struct spi_statistics, GFP_KERNEL); + + if (pcpu_stats) { + int cpu; + + for_each_possible_cpu(cpu) { + struct spi_statistics *stat; + + stat = per_cpu_ptr(pcpu_stats, cpu); + u64_stats_init(&stat->syncp); + } + } + return pcpu_stats; +} + +#define spi_pcpu_stats_totalize(ret, in, field) \ +do { \ + int i; \ + ret = 0; \ + for_each_possible_cpu(i) { \ + const struct spi_statistics *pcpu_stats; \ + u64 inc; \ + unsigned int start; \ + pcpu_stats = per_cpu_ptr(in, i); \ + do { \ + start = u64_stats_fetch_begin_irq( \ + &pcpu_stats->syncp); \ + inc = u64_stats_read(&pcpu_stats->field); \ + } while (u64_stats_fetch_retry_irq( \ + &pcpu_stats->syncp, start)); \ + ret += inc; \ + } \ +} while (0) + +#define SPI_STATISTICS_ATTRS(field, file) \ +static ssize_t spi_controller_##field##_show(struct device *dev, \ + struct device_attribute *attr, \ + char *buf) \ +{ \ + struct spi_controller *ctlr = container_of(dev, \ + struct spi_controller, dev); \ + return spi_statistics_##field##_show(ctlr->pcpu_statistics, buf); \ +} \ +static struct device_attribute dev_attr_spi_controller_##field = { \ + .attr = { .name = file, .mode = 0444 }, \ + .show = spi_controller_##field##_show, \ +}; \ +static ssize_t spi_device_##field##_show(struct device *dev, \ + struct device_attribute *attr, \ + char *buf) \ +{ \ + struct spi_device *spi = to_spi_device(dev); \ + return spi_statistics_##field##_show(spi->pcpu_statistics, buf); \ +} \ +static struct device_attribute dev_attr_spi_device_##field = { \ + .attr = { .name = file, .mode = 0444 }, \ + .show = spi_device_##field##_show, \ +} + +#define SPI_STATISTICS_SHOW_NAME(name, file, field) \ +static ssize_t spi_statistics_##name##_show(struct spi_statistics __percpu *stat, \ + char *buf) \ +{ \ + ssize_t len; \ + u64 val; \ + spi_pcpu_stats_totalize(val, stat, field); \ + len = sysfs_emit(buf, "%llu\n", val); \ + return len; \ +} \ +SPI_STATISTICS_ATTRS(name, file) + +#define SPI_STATISTICS_SHOW(field) \ + SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \ + field) + +SPI_STATISTICS_SHOW(messages); +SPI_STATISTICS_SHOW(transfers); +SPI_STATISTICS_SHOW(errors); +SPI_STATISTICS_SHOW(timedout); + +SPI_STATISTICS_SHOW(spi_sync); +SPI_STATISTICS_SHOW(spi_sync_immediate); +SPI_STATISTICS_SHOW(spi_async); + +SPI_STATISTICS_SHOW(bytes); +SPI_STATISTICS_SHOW(bytes_rx); +SPI_STATISTICS_SHOW(bytes_tx); + +#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \ + SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \ + "transfer_bytes_histo_" number, \ + transfer_bytes_histo[index]) +SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535"); +SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+"); + +SPI_STATISTICS_SHOW(transfers_split_maxsize); + +static struct attribute *spi_dev_attrs[] = { + &dev_attr_modalias.attr, + &dev_attr_driver_override.attr, + NULL, +}; + +static const struct attribute_group spi_dev_group = { + .attrs = spi_dev_attrs, +}; + +static struct attribute *spi_device_statistics_attrs[] = { + &dev_attr_spi_device_messages.attr, + &dev_attr_spi_device_transfers.attr, + &dev_attr_spi_device_errors.attr, + &dev_attr_spi_device_timedout.attr, + &dev_attr_spi_device_spi_sync.attr, + &dev_attr_spi_device_spi_sync_immediate.attr, + &dev_attr_spi_device_spi_async.attr, + &dev_attr_spi_device_bytes.attr, + &dev_attr_spi_device_bytes_rx.attr, + &dev_attr_spi_device_bytes_tx.attr, + &dev_attr_spi_device_transfer_bytes_histo0.attr, + &dev_attr_spi_device_transfer_bytes_histo1.attr, + &dev_attr_spi_device_transfer_bytes_histo2.attr, + &dev_attr_spi_device_transfer_bytes_histo3.attr, + &dev_attr_spi_device_transfer_bytes_histo4.attr, + &dev_attr_spi_device_transfer_bytes_histo5.attr, + &dev_attr_spi_device_transfer_bytes_histo6.attr, + &dev_attr_spi_device_transfer_bytes_histo7.attr, + &dev_attr_spi_device_transfer_bytes_histo8.attr, + &dev_attr_spi_device_transfer_bytes_histo9.attr, + &dev_attr_spi_device_transfer_bytes_histo10.attr, + &dev_attr_spi_device_transfer_bytes_histo11.attr, + &dev_attr_spi_device_transfer_bytes_histo12.attr, + &dev_attr_spi_device_transfer_bytes_histo13.attr, + &dev_attr_spi_device_transfer_bytes_histo14.attr, + &dev_attr_spi_device_transfer_bytes_histo15.attr, + &dev_attr_spi_device_transfer_bytes_histo16.attr, + &dev_attr_spi_device_transfers_split_maxsize.attr, + NULL, +}; + +static const struct attribute_group spi_device_statistics_group = { + .name = "statistics", + .attrs = spi_device_statistics_attrs, +}; + +static const struct attribute_group *spi_dev_groups[] = { + &spi_dev_group, + &spi_device_statistics_group, + NULL, +}; + +static struct attribute *spi_controller_statistics_attrs[] = { + &dev_attr_spi_controller_messages.attr, + &dev_attr_spi_controller_transfers.attr, + &dev_attr_spi_controller_errors.attr, + &dev_attr_spi_controller_timedout.attr, + &dev_attr_spi_controller_spi_sync.attr, + &dev_attr_spi_controller_spi_sync_immediate.attr, + &dev_attr_spi_controller_spi_async.attr, + &dev_attr_spi_controller_bytes.attr, + &dev_attr_spi_controller_bytes_rx.attr, + &dev_attr_spi_controller_bytes_tx.attr, + &dev_attr_spi_controller_transfer_bytes_histo0.attr, + &dev_attr_spi_controller_transfer_bytes_histo1.attr, + &dev_attr_spi_controller_transfer_bytes_histo2.attr, + &dev_attr_spi_controller_transfer_bytes_histo3.attr, + &dev_attr_spi_controller_transfer_bytes_histo4.attr, + &dev_attr_spi_controller_transfer_bytes_histo5.attr, + &dev_attr_spi_controller_transfer_bytes_histo6.attr, + &dev_attr_spi_controller_transfer_bytes_histo7.attr, + &dev_attr_spi_controller_transfer_bytes_histo8.attr, + &dev_attr_spi_controller_transfer_bytes_histo9.attr, + &dev_attr_spi_controller_transfer_bytes_histo10.attr, + &dev_attr_spi_controller_transfer_bytes_histo11.attr, + &dev_attr_spi_controller_transfer_bytes_histo12.attr, + &dev_attr_spi_controller_transfer_bytes_histo13.attr, + &dev_attr_spi_controller_transfer_bytes_histo14.attr, + &dev_attr_spi_controller_transfer_bytes_histo15.attr, + &dev_attr_spi_controller_transfer_bytes_histo16.attr, + &dev_attr_spi_controller_transfers_split_maxsize.attr, + NULL, +}; + +static const struct attribute_group spi_controller_statistics_group = { + .name = "statistics", + .attrs = spi_controller_statistics_attrs, +}; + +static const struct attribute_group *spi_master_groups[] = { + &spi_controller_statistics_group, + NULL, +}; + +static void spi_statistics_add_transfer_stats(struct spi_statistics __percpu *pcpu_stats, + struct spi_transfer *xfer, + struct spi_controller *ctlr) +{ + int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1; + struct spi_statistics *stats; + + if (l2len < 0) + l2len = 0; + + get_cpu(); + stats = this_cpu_ptr(pcpu_stats); + u64_stats_update_begin(&stats->syncp); + + u64_stats_inc(&stats->transfers); + u64_stats_inc(&stats->transfer_bytes_histo[l2len]); + + u64_stats_add(&stats->bytes, xfer->len); + if ((xfer->tx_buf) && + (xfer->tx_buf != ctlr->dummy_tx)) + u64_stats_add(&stats->bytes_tx, xfer->len); + if ((xfer->rx_buf) && + (xfer->rx_buf != ctlr->dummy_rx)) + u64_stats_add(&stats->bytes_rx, xfer->len); + + u64_stats_update_end(&stats->syncp); + put_cpu(); +} + +/* + * modalias support makes "modprobe $MODALIAS" new-style hotplug work, + * and the sysfs version makes coldplug work too. + */ +static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, const char *name) +{ + while (id->name[0]) { + if (!strcmp(name, id->name)) + return id; + id++; + } + return NULL; +} + +const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev) +{ + const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver); + + return spi_match_id(sdrv->id_table, sdev->modalias); +} +EXPORT_SYMBOL_GPL(spi_get_device_id); + +const void *spi_get_device_match_data(const struct spi_device *sdev) +{ + const void *match; + + match = device_get_match_data(&sdev->dev); + if (match) + return match; + + return (const void *)spi_get_device_id(sdev)->driver_data; +} +EXPORT_SYMBOL_GPL(spi_get_device_match_data); + +static int spi_match_device(struct device *dev, struct device_driver *drv) +{ + const struct spi_device *spi = to_spi_device(dev); + const struct spi_driver *sdrv = to_spi_driver(drv); + + /* Check override first, and if set, only use the named driver */ + if (spi->driver_override) + return strcmp(spi->driver_override, drv->name) == 0; + + /* Attempt an OF style match */ + if (of_driver_match_device(dev, drv)) + return 1; + + /* Then try ACPI */ + if (acpi_driver_match_device(dev, drv)) + return 1; + + if (sdrv->id_table) + return !!spi_match_id(sdrv->id_table, spi->modalias); + + return strcmp(spi->modalias, drv->name) == 0; +} + +static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + const struct spi_device *spi = to_spi_device(dev); + int rc; + + rc = acpi_device_uevent_modalias(dev, env); + if (rc != -ENODEV) + return rc; + + return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); +} + +static int spi_probe(struct device *dev) +{ + const struct spi_driver *sdrv = to_spi_driver(dev->driver); + struct spi_device *spi = to_spi_device(dev); + int ret; + + ret = of_clk_set_defaults(dev->of_node, false); + if (ret) + return ret; + + if (dev->of_node) { + spi->irq = of_irq_get(dev->of_node, 0); + if (spi->irq == -EPROBE_DEFER) + return -EPROBE_DEFER; + if (spi->irq < 0) + spi->irq = 0; + } + + ret = dev_pm_domain_attach(dev, true); + if (ret) + return ret; + + if (sdrv->probe) { + ret = sdrv->probe(spi); + if (ret) + dev_pm_domain_detach(dev, true); + } + + return ret; +} + +static void spi_remove(struct device *dev) +{ + const struct spi_driver *sdrv = to_spi_driver(dev->driver); + + if (sdrv->remove) + sdrv->remove(to_spi_device(dev)); + + dev_pm_domain_detach(dev, true); +} + +static void spi_shutdown(struct device *dev) +{ + if (dev->driver) { + const struct spi_driver *sdrv = to_spi_driver(dev->driver); + + if (sdrv->shutdown) + sdrv->shutdown(to_spi_device(dev)); + } +} + +struct bus_type spi_bus_type = { + .name = "spi", + .dev_groups = spi_dev_groups, + .match = spi_match_device, + .uevent = spi_uevent, + .probe = spi_probe, + .remove = spi_remove, + .shutdown = spi_shutdown, +}; +EXPORT_SYMBOL_GPL(spi_bus_type); + +/** + * __spi_register_driver - register a SPI driver + * @owner: owner module of the driver to register + * @sdrv: the driver to register + * Context: can sleep + * + * Return: zero on success, else a negative error code. + */ +int __spi_register_driver(struct module *owner, struct spi_driver *sdrv) +{ + sdrv->driver.owner = owner; + sdrv->driver.bus = &spi_bus_type; + + /* + * For Really Good Reasons we use spi: modaliases not of: + * modaliases for DT so module autoloading won't work if we + * don't have a spi_device_id as well as a compatible string. + */ + if (sdrv->driver.of_match_table) { + const struct of_device_id *of_id; + + for (of_id = sdrv->driver.of_match_table; of_id->compatible[0]; + of_id++) { + const char *of_name; + + /* Strip off any vendor prefix */ + of_name = strnchr(of_id->compatible, + sizeof(of_id->compatible), ','); + if (of_name) + of_name++; + else + of_name = of_id->compatible; + + if (sdrv->id_table) { + const struct spi_device_id *spi_id; + + spi_id = spi_match_id(sdrv->id_table, of_name); + if (spi_id) + continue; + } else { + if (strcmp(sdrv->driver.name, of_name) == 0) + continue; + } + + pr_warn("SPI driver %s has no spi_device_id for %s\n", + sdrv->driver.name, of_id->compatible); + } + } + + return driver_register(&sdrv->driver); +} +EXPORT_SYMBOL_GPL(__spi_register_driver); + +/*-------------------------------------------------------------------------*/ + +/* + * SPI devices should normally not be created by SPI device drivers; that + * would make them board-specific. Similarly with SPI controller drivers. + * Device registration normally goes into like arch/.../mach.../board-YYY.c + * with other readonly (flashable) information about mainboard devices. + */ + +struct boardinfo { + struct list_head list; + struct spi_board_info board_info; +}; + +static LIST_HEAD(board_list); +static LIST_HEAD(spi_controller_list); + +/* + * Used to protect add/del operation for board_info list and + * spi_controller list, and their matching process also used + * to protect object of type struct idr. + */ +static DEFINE_MUTEX(board_lock); + +/** + * spi_alloc_device - Allocate a new SPI device + * @ctlr: Controller to which device is connected + * Context: can sleep + * + * Allows a driver to allocate and initialize a spi_device without + * registering it immediately. This allows a driver to directly + * fill the spi_device with device parameters before calling + * spi_add_device() on it. + * + * Caller is responsible to call spi_add_device() on the returned + * spi_device structure to add it to the SPI controller. If the caller + * needs to discard the spi_device without adding it, then it should + * call spi_dev_put() on it. + * + * Return: a pointer to the new device, or NULL. + */ +struct spi_device *spi_alloc_device(struct spi_controller *ctlr) +{ + struct spi_device *spi; + + if (!spi_controller_get(ctlr)) + return NULL; + + spi = kzalloc(sizeof(*spi), GFP_KERNEL); + if (!spi) { + spi_controller_put(ctlr); + return NULL; + } + + spi->pcpu_statistics = spi_alloc_pcpu_stats(NULL); + if (!spi->pcpu_statistics) { + kfree(spi); + spi_controller_put(ctlr); + return NULL; + } + + spi->master = spi->controller = ctlr; + spi->dev.parent = &ctlr->dev; + spi->dev.bus = &spi_bus_type; + spi->dev.release = spidev_release; + spi->mode = ctlr->buswidth_override_bits; + + device_initialize(&spi->dev); + return spi; +} +EXPORT_SYMBOL_GPL(spi_alloc_device); + +static void spi_dev_set_name(struct spi_device *spi) +{ + struct acpi_device *adev = ACPI_COMPANION(&spi->dev); + + if (adev) { + dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev)); + return; + } + + dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev), + spi_get_chipselect(spi, 0)); +} + +static int spi_dev_check(struct device *dev, void *data) +{ + struct spi_device *spi = to_spi_device(dev); + struct spi_device *new_spi = data; + + if (spi->controller == new_spi->controller && + spi_get_chipselect(spi, 0) == spi_get_chipselect(new_spi, 0)) + return -EBUSY; + return 0; +} + +static void spi_cleanup(struct spi_device *spi) +{ + if (spi->controller->cleanup) + spi->controller->cleanup(spi); +} + +static int __spi_add_device(struct spi_device *spi) +{ + struct spi_controller *ctlr = spi->controller; + struct device *dev = ctlr->dev.parent; + int status; + + /* + * We need to make sure there's no other device with this + * chipselect **BEFORE** we call setup(), else we'll trash + * its configuration. + */ + status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); + if (status) { + dev_err(dev, "chipselect %d already in use\n", + spi_get_chipselect(spi, 0)); + return status; + } + + /* Controller may unregister concurrently */ + if (IS_ENABLED(CONFIG_SPI_DYNAMIC) && + !device_is_registered(&ctlr->dev)) { + return -ENODEV; + } + + if (ctlr->cs_gpiods) + spi_set_csgpiod(spi, 0, ctlr->cs_gpiods[spi_get_chipselect(spi, 0)]); + + /* + * Drivers may modify this initial i/o setup, but will + * normally rely on the device being setup. Devices + * using SPI_CS_HIGH can't coexist well otherwise... + */ + status = spi_setup(spi); + if (status < 0) { + dev_err(dev, "can't setup %s, status %d\n", + dev_name(&spi->dev), status); + return status; + } + + /* Device may be bound to an active driver when this returns */ + status = device_add(&spi->dev); + if (status < 0) { + dev_err(dev, "can't add %s, status %d\n", + dev_name(&spi->dev), status); + spi_cleanup(spi); + } else { + dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); + } + + return status; +} + +/** + * spi_add_device - Add spi_device allocated with spi_alloc_device + * @spi: spi_device to register + * + * Companion function to spi_alloc_device. Devices allocated with + * spi_alloc_device can be added onto the spi bus with this function. + * + * Return: 0 on success; negative errno on failure + */ +int spi_add_device(struct spi_device *spi) +{ + struct spi_controller *ctlr = spi->controller; + struct device *dev = ctlr->dev.parent; + int status; + + /* Chipselects are numbered 0..max; validate. */ + if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) { + dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0), + ctlr->num_chipselect); + return -EINVAL; + } + + /* Set the bus ID string */ + spi_dev_set_name(spi); + + mutex_lock(&ctlr->add_lock); + status = __spi_add_device(spi); + mutex_unlock(&ctlr->add_lock); + return status; +} +EXPORT_SYMBOL_GPL(spi_add_device); + +static int spi_add_device_locked(struct spi_device *spi) +{ + struct spi_controller *ctlr = spi->controller; + struct device *dev = ctlr->dev.parent; + + /* Chipselects are numbered 0..max; validate. */ + if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) { + dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0), + ctlr->num_chipselect); + return -EINVAL; + } + + /* Set the bus ID string */ + spi_dev_set_name(spi); + + WARN_ON(!mutex_is_locked(&ctlr->add_lock)); + return __spi_add_device(spi); +} + +/** + * spi_new_device - instantiate one new SPI device + * @ctlr: Controller to which device is connected + * @chip: Describes the SPI device + * Context: can sleep + * + * On typical mainboards, this is purely internal; and it's not needed + * after board init creates the hard-wired devices. Some development + * platforms may not be able to use spi_register_board_info though, and + * this is exported so that for example a USB or parport based adapter + * driver could add devices (which it would learn about out-of-band). + * + * Return: the new device, or NULL. + */ +struct spi_device *spi_new_device(struct spi_controller *ctlr, + struct spi_board_info *chip) +{ + struct spi_device *proxy; + int status; + + /* + * NOTE: caller did any chip->bus_num checks necessary. + * + * Also, unless we change the return value convention to use + * error-or-pointer (not NULL-or-pointer), troubleshootability + * suggests syslogged diagnostics are best here (ugh). + */ + + proxy = spi_alloc_device(ctlr); + if (!proxy) + return NULL; + + WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); + + spi_set_chipselect(proxy, 0, chip->chip_select); + proxy->max_speed_hz = chip->max_speed_hz; + proxy->mode = chip->mode; + proxy->irq = chip->irq; + strscpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); + proxy->dev.platform_data = (void *) chip->platform_data; + proxy->controller_data = chip->controller_data; + proxy->controller_state = NULL; + + if (chip->swnode) { + status = device_add_software_node(&proxy->dev, chip->swnode); + if (status) { + dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n", + chip->modalias, status); + goto err_dev_put; + } + } + + status = spi_add_device(proxy); + if (status < 0) + goto err_dev_put; + + return proxy; + +err_dev_put: + device_remove_software_node(&proxy->dev); + spi_dev_put(proxy); + return NULL; +} +EXPORT_SYMBOL_GPL(spi_new_device); + +/** + * spi_unregister_device - unregister a single SPI device + * @spi: spi_device to unregister + * + * Start making the passed SPI device vanish. Normally this would be handled + * by spi_unregister_controller(). + */ +void spi_unregister_device(struct spi_device *spi) +{ + if (!spi) + return; + + if (spi->dev.of_node) { + of_node_clear_flag(spi->dev.of_node, OF_POPULATED); + of_node_put(spi->dev.of_node); + } + if (ACPI_COMPANION(&spi->dev)) + acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev)); + device_remove_software_node(&spi->dev); + device_del(&spi->dev); + spi_cleanup(spi); + put_device(&spi->dev); +} +EXPORT_SYMBOL_GPL(spi_unregister_device); + +static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr, + struct spi_board_info *bi) +{ + struct spi_device *dev; + + if (ctlr->bus_num != bi->bus_num) + return; + + dev = spi_new_device(ctlr, bi); + if (!dev) + dev_err(ctlr->dev.parent, "can't create new device for %s\n", + bi->modalias); +} + +/** + * spi_register_board_info - register SPI devices for a given board + * @info: array of chip descriptors + * @n: how many descriptors are provided + * Context: can sleep + * + * Board-specific early init code calls this (probably during arch_initcall) + * with segments of the SPI device table. Any device nodes are created later, + * after the relevant parent SPI controller (bus_num) is defined. We keep + * this table of devices forever, so that reloading a controller driver will + * not make Linux forget about these hard-wired devices. + * + * Other code can also call this, e.g. a particular add-on board might provide + * SPI devices through its expansion connector, so code initializing that board + * would naturally declare its SPI devices. + * + * The board info passed can safely be __initdata ... but be careful of + * any embedded pointers (platform_data, etc), they're copied as-is. + * + * Return: zero on success, else a negative error code. + */ +int spi_register_board_info(struct spi_board_info const *info, unsigned n) +{ + struct boardinfo *bi; + int i; + + if (!n) + return 0; + + bi = kcalloc(n, sizeof(*bi), GFP_KERNEL); + if (!bi) + return -ENOMEM; + + for (i = 0; i < n; i++, bi++, info++) { + struct spi_controller *ctlr; + + memcpy(&bi->board_info, info, sizeof(*info)); + + mutex_lock(&board_lock); + list_add_tail(&bi->list, &board_list); + list_for_each_entry(ctlr, &spi_controller_list, list) + spi_match_controller_to_boardinfo(ctlr, + &bi->board_info); + mutex_unlock(&board_lock); + } + + return 0; +} + +/*-------------------------------------------------------------------------*/ + +/* Core methods for SPI resource management */ + +/** + * spi_res_alloc - allocate a spi resource that is life-cycle managed + * during the processing of a spi_message while using + * spi_transfer_one + * @spi: the spi device for which we allocate memory + * @release: the release code to execute for this resource + * @size: size to alloc and return + * @gfp: GFP allocation flags + * + * Return: the pointer to the allocated data + * + * This may get enhanced in the future to allocate from a memory pool + * of the @spi_device or @spi_controller to avoid repeated allocations. + */ +static void *spi_res_alloc(struct spi_device *spi, spi_res_release_t release, + size_t size, gfp_t gfp) +{ + struct spi_res *sres; + + sres = kzalloc(sizeof(*sres) + size, gfp); + if (!sres) + return NULL; + + INIT_LIST_HEAD(&sres->entry); + sres->release = release; + + return sres->data; +} + +/** + * spi_res_free - free an spi resource + * @res: pointer to the custom data of a resource + */ +static void spi_res_free(void *res) +{ + struct spi_res *sres = container_of(res, struct spi_res, data); + + if (!res) + return; + + WARN_ON(!list_empty(&sres->entry)); + kfree(sres); +} + +/** + * spi_res_add - add a spi_res to the spi_message + * @message: the spi message + * @res: the spi_resource + */ +static void spi_res_add(struct spi_message *message, void *res) +{ + struct spi_res *sres = container_of(res, struct spi_res, data); + + WARN_ON(!list_empty(&sres->entry)); + list_add_tail(&sres->entry, &message->resources); +} + +/** + * spi_res_release - release all spi resources for this message + * @ctlr: the @spi_controller + * @message: the @spi_message + */ +static void spi_res_release(struct spi_controller *ctlr, struct spi_message *message) +{ + struct spi_res *res, *tmp; + + list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) { + if (res->release) + res->release(ctlr, message, res->data); + + list_del(&res->entry); + + kfree(res); + } +} + +/*-------------------------------------------------------------------------*/ + +static void spi_set_cs(struct spi_device *spi, bool enable, bool force) +{ + bool activate = enable; + + /* + * Avoid calling into the driver (or doing delays) if the chip select + * isn't actually changing from the last time this was called. + */ + if (!force && ((enable && spi->controller->last_cs == spi_get_chipselect(spi, 0)) || + (!enable && spi->controller->last_cs != spi_get_chipselect(spi, 0))) && + (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH))) + return; + + trace_spi_set_cs(spi, activate); + + spi->controller->last_cs = enable ? spi_get_chipselect(spi, 0) : -1; + spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH; + + if ((spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) && !activate) + spi_delay_exec(&spi->cs_hold, NULL); + + if (spi->mode & SPI_CS_HIGH) + enable = !enable; + + if (spi_get_csgpiod(spi, 0)) { + if (!(spi->mode & SPI_NO_CS)) { + /* + * Historically ACPI has no means of the GPIO polarity and + * thus the SPISerialBus() resource defines it on the per-chip + * basis. In order to avoid a chain of negations, the GPIO + * polarity is considered being Active High. Even for the cases + * when _DSD() is involved (in the updated versions of ACPI) + * the GPIO CS polarity must be defined Active High to avoid + * ambiguity. That's why we use enable, that takes SPI_CS_HIGH + * into account. + */ + if (has_acpi_companion(&spi->dev)) + gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), !enable); + else + /* Polarity handled by GPIO library */ + gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), activate); + } + /* Some SPI masters need both GPIO CS & slave_select */ + if ((spi->controller->flags & SPI_MASTER_GPIO_SS) && + spi->controller->set_cs) + spi->controller->set_cs(spi, !enable); + } else if (spi->controller->set_cs) { + spi->controller->set_cs(spi, !enable); + } + + if (spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) { + if (activate) + spi_delay_exec(&spi->cs_setup, NULL); + else + spi_delay_exec(&spi->cs_inactive, NULL); + } +} + +#ifdef CONFIG_HAS_DMA +static int spi_map_buf_attrs(struct spi_controller *ctlr, struct device *dev, + struct sg_table *sgt, void *buf, size_t len, + enum dma_data_direction dir, unsigned long attrs) +{ + const bool vmalloced_buf = is_vmalloc_addr(buf); + unsigned int max_seg_size = dma_get_max_seg_size(dev); +#ifdef CONFIG_HIGHMEM + const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE && + (unsigned long)buf < (PKMAP_BASE + + (LAST_PKMAP * PAGE_SIZE))); +#else + const bool kmap_buf = false; +#endif + int desc_len; + int sgs; + struct page *vm_page; + struct scatterlist *sg; + void *sg_buf; + size_t min; + int i, ret; + + if (vmalloced_buf || kmap_buf) { + desc_len = min_t(unsigned long, max_seg_size, PAGE_SIZE); + sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len); + } else if (virt_addr_valid(buf)) { + desc_len = min_t(size_t, max_seg_size, ctlr->max_dma_len); + sgs = DIV_ROUND_UP(len, desc_len); + } else { + return -EINVAL; + } + + ret = sg_alloc_table(sgt, sgs, GFP_KERNEL); + if (ret != 0) + return ret; + + sg = &sgt->sgl[0]; + for (i = 0; i < sgs; i++) { + + if (vmalloced_buf || kmap_buf) { + /* + * Next scatterlist entry size is the minimum between + * the desc_len and the remaining buffer length that + * fits in a page. + */ + min = min_t(size_t, desc_len, + min_t(size_t, len, + PAGE_SIZE - offset_in_page(buf))); + if (vmalloced_buf) + vm_page = vmalloc_to_page(buf); + else + vm_page = kmap_to_page(buf); + if (!vm_page) { + sg_free_table(sgt); + return -ENOMEM; + } + sg_set_page(sg, vm_page, + min, offset_in_page(buf)); + } else { + min = min_t(size_t, len, desc_len); + sg_buf = buf; + sg_set_buf(sg, sg_buf, min); + } + + buf += min; + len -= min; + sg = sg_next(sg); + } + + ret = dma_map_sgtable(dev, sgt, dir, attrs); + if (ret < 0) { + sg_free_table(sgt); + return ret; + } + + return 0; +} + +int spi_map_buf(struct spi_controller *ctlr, struct device *dev, + struct sg_table *sgt, void *buf, size_t len, + enum dma_data_direction dir) +{ + return spi_map_buf_attrs(ctlr, dev, sgt, buf, len, dir, 0); +} + +static void spi_unmap_buf_attrs(struct spi_controller *ctlr, + struct device *dev, struct sg_table *sgt, + enum dma_data_direction dir, + unsigned long attrs) +{ + if (sgt->orig_nents) { + dma_unmap_sgtable(dev, sgt, dir, attrs); + sg_free_table(sgt); + sgt->orig_nents = 0; + sgt->nents = 0; + } +} + +void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev, + struct sg_table *sgt, enum dma_data_direction dir) +{ + spi_unmap_buf_attrs(ctlr, dev, sgt, dir, 0); +} + +static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) +{ + struct device *tx_dev, *rx_dev; + struct spi_transfer *xfer; + int ret; + + if (!ctlr->can_dma) + return 0; + + if (ctlr->dma_tx) + tx_dev = ctlr->dma_tx->device->dev; + else if (ctlr->dma_map_dev) + tx_dev = ctlr->dma_map_dev; + else + tx_dev = ctlr->dev.parent; + + if (ctlr->dma_rx) + rx_dev = ctlr->dma_rx->device->dev; + else if (ctlr->dma_map_dev) + rx_dev = ctlr->dma_map_dev; + else + rx_dev = ctlr->dev.parent; + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + /* The sync is done before each transfer. */ + unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC; + + if (!ctlr->can_dma(ctlr, msg->spi, xfer)) + continue; + + if (xfer->tx_buf != NULL) { + ret = spi_map_buf_attrs(ctlr, tx_dev, &xfer->tx_sg, + (void *)xfer->tx_buf, + xfer->len, DMA_TO_DEVICE, + attrs); + if (ret != 0) + return ret; + } + + if (xfer->rx_buf != NULL) { + ret = spi_map_buf_attrs(ctlr, rx_dev, &xfer->rx_sg, + xfer->rx_buf, xfer->len, + DMA_FROM_DEVICE, attrs); + if (ret != 0) { + spi_unmap_buf_attrs(ctlr, tx_dev, + &xfer->tx_sg, DMA_TO_DEVICE, + attrs); + + return ret; + } + } + } + + ctlr->cur_rx_dma_dev = rx_dev; + ctlr->cur_tx_dma_dev = tx_dev; + ctlr->cur_msg_mapped = true; + + return 0; +} + +static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg) +{ + struct device *rx_dev = ctlr->cur_rx_dma_dev; + struct device *tx_dev = ctlr->cur_tx_dma_dev; + struct spi_transfer *xfer; + + if (!ctlr->cur_msg_mapped || !ctlr->can_dma) + return 0; + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + /* The sync has already been done after each transfer. */ + unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC; + + if (!ctlr->can_dma(ctlr, msg->spi, xfer)) + continue; + + spi_unmap_buf_attrs(ctlr, rx_dev, &xfer->rx_sg, + DMA_FROM_DEVICE, attrs); + spi_unmap_buf_attrs(ctlr, tx_dev, &xfer->tx_sg, + DMA_TO_DEVICE, attrs); + } + + ctlr->cur_msg_mapped = false; + + return 0; +} + +static void spi_dma_sync_for_device(struct spi_controller *ctlr, + struct spi_transfer *xfer) +{ + struct device *rx_dev = ctlr->cur_rx_dma_dev; + struct device *tx_dev = ctlr->cur_tx_dma_dev; + + if (!ctlr->cur_msg_mapped) + return; + + if (xfer->tx_sg.orig_nents) + dma_sync_sgtable_for_device(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); + if (xfer->rx_sg.orig_nents) + dma_sync_sgtable_for_device(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); +} + +static void spi_dma_sync_for_cpu(struct spi_controller *ctlr, + struct spi_transfer *xfer) +{ + struct device *rx_dev = ctlr->cur_rx_dma_dev; + struct device *tx_dev = ctlr->cur_tx_dma_dev; + + if (!ctlr->cur_msg_mapped) + return; + + if (xfer->rx_sg.orig_nents) + dma_sync_sgtable_for_cpu(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); + if (xfer->tx_sg.orig_nents) + dma_sync_sgtable_for_cpu(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); +} +#else /* !CONFIG_HAS_DMA */ +static inline int __spi_map_msg(struct spi_controller *ctlr, + struct spi_message *msg) +{ + return 0; +} + +static inline int __spi_unmap_msg(struct spi_controller *ctlr, + struct spi_message *msg) +{ + return 0; +} + +static void spi_dma_sync_for_device(struct spi_controller *ctrl, + struct spi_transfer *xfer) +{ +} + +static void spi_dma_sync_for_cpu(struct spi_controller *ctrl, + struct spi_transfer *xfer) +{ +} +#endif /* !CONFIG_HAS_DMA */ + +static inline int spi_unmap_msg(struct spi_controller *ctlr, + struct spi_message *msg) +{ + struct spi_transfer *xfer; + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + /* + * Restore the original value of tx_buf or rx_buf if they are + * NULL. + */ + if (xfer->tx_buf == ctlr->dummy_tx) + xfer->tx_buf = NULL; + if (xfer->rx_buf == ctlr->dummy_rx) + xfer->rx_buf = NULL; + } + + return __spi_unmap_msg(ctlr, msg); +} + +static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) +{ + struct spi_transfer *xfer; + void *tmp; + unsigned int max_tx, max_rx; + + if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) + && !(msg->spi->mode & SPI_3WIRE)) { + max_tx = 0; + max_rx = 0; + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) && + !xfer->tx_buf) + max_tx = max(xfer->len, max_tx); + if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) && + !xfer->rx_buf) + max_rx = max(xfer->len, max_rx); + } + + if (max_tx) { + tmp = krealloc(ctlr->dummy_tx, max_tx, + GFP_KERNEL | GFP_DMA | __GFP_ZERO); + if (!tmp) + return -ENOMEM; + ctlr->dummy_tx = tmp; + } + + if (max_rx) { + tmp = krealloc(ctlr->dummy_rx, max_rx, + GFP_KERNEL | GFP_DMA); + if (!tmp) + return -ENOMEM; + ctlr->dummy_rx = tmp; + } + + if (max_tx || max_rx) { + list_for_each_entry(xfer, &msg->transfers, + transfer_list) { + if (!xfer->len) + continue; + if (!xfer->tx_buf) + xfer->tx_buf = ctlr->dummy_tx; + if (!xfer->rx_buf) + xfer->rx_buf = ctlr->dummy_rx; + } + } + } + + return __spi_map_msg(ctlr, msg); +} + +static int spi_transfer_wait(struct spi_controller *ctlr, + struct spi_message *msg, + struct spi_transfer *xfer) +{ + struct spi_statistics __percpu *statm = ctlr->pcpu_statistics; + struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics; + u32 speed_hz = xfer->speed_hz; + unsigned long long ms; + + if (spi_controller_is_slave(ctlr)) { + if (wait_for_completion_interruptible(&ctlr->xfer_completion)) { + dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n"); + return -EINTR; + } + } else { + if (!speed_hz) + speed_hz = 100000; + + /* + * For each byte we wait for 8 cycles of the SPI clock. + * Since speed is defined in Hz and we want milliseconds, + * use respective multiplier, but before the division, + * otherwise we may get 0 for short transfers. + */ + ms = 8LL * MSEC_PER_SEC * xfer->len; + do_div(ms, speed_hz); + + /* + * Increase it twice and add 200 ms tolerance, use + * predefined maximum in case of overflow. + */ + ms += ms + 200; + if (ms > UINT_MAX) + ms = UINT_MAX; + + ms = wait_for_completion_timeout(&ctlr->xfer_completion, + msecs_to_jiffies(ms)); + + if (ms == 0) { + SPI_STATISTICS_INCREMENT_FIELD(statm, timedout); + SPI_STATISTICS_INCREMENT_FIELD(stats, timedout); + dev_err(&msg->spi->dev, + "SPI transfer timed out\n"); + return -ETIMEDOUT; + } + } + + return 0; +} + +static void _spi_transfer_delay_ns(u32 ns) +{ + if (!ns) + return; + if (ns <= NSEC_PER_USEC) { + ndelay(ns); + } else { + u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC); + + if (us <= 10) + udelay(us); + else + usleep_range(us, us + DIV_ROUND_UP(us, 10)); + } +} + +int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer) +{ + u32 delay = _delay->value; + u32 unit = _delay->unit; + u32 hz; + + if (!delay) + return 0; + + switch (unit) { + case SPI_DELAY_UNIT_USECS: + delay *= NSEC_PER_USEC; + break; + case SPI_DELAY_UNIT_NSECS: + /* Nothing to do here */ + break; + case SPI_DELAY_UNIT_SCK: + /* Clock cycles need to be obtained from spi_transfer */ + if (!xfer) + return -EINVAL; + /* + * If there is unknown effective speed, approximate it + * by underestimating with half of the requested hz. + */ + hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2; + if (!hz) + return -EINVAL; + + /* Convert delay to nanoseconds */ + delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz); + break; + default: + return -EINVAL; + } + + return delay; +} +EXPORT_SYMBOL_GPL(spi_delay_to_ns); + +int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer) +{ + int delay; + + might_sleep(); + + if (!_delay) + return -EINVAL; + + delay = spi_delay_to_ns(_delay, xfer); + if (delay < 0) + return delay; + + _spi_transfer_delay_ns(delay); + + return 0; +} +EXPORT_SYMBOL_GPL(spi_delay_exec); + +static void _spi_transfer_cs_change_delay(struct spi_message *msg, + struct spi_transfer *xfer) +{ + u32 default_delay_ns = 10 * NSEC_PER_USEC; + u32 delay = xfer->cs_change_delay.value; + u32 unit = xfer->cs_change_delay.unit; + int ret; + + /* Return early on "fast" mode - for everything but USECS */ + if (!delay) { + if (unit == SPI_DELAY_UNIT_USECS) + _spi_transfer_delay_ns(default_delay_ns); + return; + } + + ret = spi_delay_exec(&xfer->cs_change_delay, xfer); + if (ret) { + dev_err_once(&msg->spi->dev, + "Use of unsupported delay unit %i, using default of %luus\n", + unit, default_delay_ns / NSEC_PER_USEC); + _spi_transfer_delay_ns(default_delay_ns); + } +} + +/* + * spi_transfer_one_message - Default implementation of transfer_one_message() + * + * This is a standard implementation of transfer_one_message() for + * drivers which implement a transfer_one() operation. It provides + * standard handling of delays and chip select management. + */ +static int spi_transfer_one_message(struct spi_controller *ctlr, + struct spi_message *msg) +{ + struct spi_transfer *xfer; + bool keep_cs = false; + int ret = 0; + struct spi_statistics __percpu *statm = ctlr->pcpu_statistics; + struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics; + + xfer = list_first_entry(&msg->transfers, struct spi_transfer, transfer_list); + spi_set_cs(msg->spi, !xfer->cs_off, false); + + SPI_STATISTICS_INCREMENT_FIELD(statm, messages); + SPI_STATISTICS_INCREMENT_FIELD(stats, messages); + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + trace_spi_transfer_start(msg, xfer); + + spi_statistics_add_transfer_stats(statm, xfer, ctlr); + spi_statistics_add_transfer_stats(stats, xfer, ctlr); + + if (!ctlr->ptp_sts_supported) { + xfer->ptp_sts_word_pre = 0; + ptp_read_system_prets(xfer->ptp_sts); + } + + if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) { + reinit_completion(&ctlr->xfer_completion); + +fallback_pio: + spi_dma_sync_for_device(ctlr, xfer); + ret = ctlr->transfer_one(ctlr, msg->spi, xfer); + if (ret < 0) { + spi_dma_sync_for_cpu(ctlr, xfer); + + if (ctlr->cur_msg_mapped && + (xfer->error & SPI_TRANS_FAIL_NO_START)) { + __spi_unmap_msg(ctlr, msg); + ctlr->fallback = true; + xfer->error &= ~SPI_TRANS_FAIL_NO_START; + goto fallback_pio; + } + + SPI_STATISTICS_INCREMENT_FIELD(statm, + errors); + SPI_STATISTICS_INCREMENT_FIELD(stats, + errors); + dev_err(&msg->spi->dev, + "SPI transfer failed: %d\n", ret); + goto out; + } + + if (ret > 0) { + ret = spi_transfer_wait(ctlr, msg, xfer); + if (ret < 0) + msg->status = ret; + } + + spi_dma_sync_for_cpu(ctlr, xfer); + } else { + if (xfer->len) + dev_err(&msg->spi->dev, + "Bufferless transfer has length %u\n", + xfer->len); + } + + if (!ctlr->ptp_sts_supported) { + ptp_read_system_postts(xfer->ptp_sts); + xfer->ptp_sts_word_post = xfer->len; + } + + trace_spi_transfer_stop(msg, xfer); + + if (msg->status != -EINPROGRESS) + goto out; + + spi_transfer_delay_exec(xfer); + + if (xfer->cs_change) { + if (list_is_last(&xfer->transfer_list, + &msg->transfers)) { + keep_cs = true; + } else { + if (!xfer->cs_off) + spi_set_cs(msg->spi, false, false); + _spi_transfer_cs_change_delay(msg, xfer); + if (!list_next_entry(xfer, transfer_list)->cs_off) + spi_set_cs(msg->spi, true, false); + } + } else if (!list_is_last(&xfer->transfer_list, &msg->transfers) && + xfer->cs_off != list_next_entry(xfer, transfer_list)->cs_off) { + spi_set_cs(msg->spi, xfer->cs_off, false); + } + + msg->actual_length += xfer->len; + } + +out: + if (ret != 0 || !keep_cs) + spi_set_cs(msg->spi, false, false); + + if (msg->status == -EINPROGRESS) + msg->status = ret; + + if (msg->status && ctlr->handle_err) + ctlr->handle_err(ctlr, msg); + + spi_finalize_current_message(ctlr); + + return ret; +} + +/** + * spi_finalize_current_transfer - report completion of a transfer + * @ctlr: the controller reporting completion + * + * Called by SPI drivers using the core transfer_one_message() + * implementation to notify it that the current interrupt driven + * transfer has finished and the next one may be scheduled. + */ +void spi_finalize_current_transfer(struct spi_controller *ctlr) +{ + complete(&ctlr->xfer_completion); +} +EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); + +static void spi_idle_runtime_pm(struct spi_controller *ctlr) +{ + if (ctlr->auto_runtime_pm) { + pm_runtime_mark_last_busy(ctlr->dev.parent); + pm_runtime_put_autosuspend(ctlr->dev.parent); + } +} + +static int __spi_pump_transfer_message(struct spi_controller *ctlr, + struct spi_message *msg, bool was_busy) +{ + struct spi_transfer *xfer; + int ret; + + if (!was_busy && ctlr->auto_runtime_pm) { + ret = pm_runtime_get_sync(ctlr->dev.parent); + if (ret < 0) { + pm_runtime_put_noidle(ctlr->dev.parent); + dev_err(&ctlr->dev, "Failed to power device: %d\n", + ret); + + msg->status = ret; + spi_finalize_current_message(ctlr); + + return ret; + } + } + + if (!was_busy) + trace_spi_controller_busy(ctlr); + + if (!was_busy && ctlr->prepare_transfer_hardware) { + ret = ctlr->prepare_transfer_hardware(ctlr); + if (ret) { + dev_err(&ctlr->dev, + "failed to prepare transfer hardware: %d\n", + ret); + + if (ctlr->auto_runtime_pm) + pm_runtime_put(ctlr->dev.parent); + + msg->status = ret; + spi_finalize_current_message(ctlr); + + return ret; + } + } + + trace_spi_message_start(msg); + + ret = spi_split_transfers_maxsize(ctlr, msg, + spi_max_transfer_size(msg->spi), + GFP_KERNEL | GFP_DMA); + if (ret) { + msg->status = ret; + spi_finalize_current_message(ctlr); + return ret; + } + + if (ctlr->prepare_message) { + ret = ctlr->prepare_message(ctlr, msg); + if (ret) { + dev_err(&ctlr->dev, "failed to prepare message: %d\n", + ret); + msg->status = ret; + spi_finalize_current_message(ctlr); + return ret; + } + msg->prepared = true; + } + + ret = spi_map_msg(ctlr, msg); + if (ret) { + msg->status = ret; + spi_finalize_current_message(ctlr); + return ret; + } + + if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) { + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + xfer->ptp_sts_word_pre = 0; + ptp_read_system_prets(xfer->ptp_sts); + } + } + + /* + * Drivers implementation of transfer_one_message() must arrange for + * spi_finalize_current_message() to get called. Most drivers will do + * this in the calling context, but some don't. For those cases, a + * completion is used to guarantee that this function does not return + * until spi_finalize_current_message() is done accessing + * ctlr->cur_msg. + * Use of the following two flags enable to opportunistically skip the + * use of the completion since its use involves expensive spin locks. + * In case of a race with the context that calls + * spi_finalize_current_message() the completion will always be used, + * due to strict ordering of these flags using barriers. + */ + WRITE_ONCE(ctlr->cur_msg_incomplete, true); + WRITE_ONCE(ctlr->cur_msg_need_completion, false); + reinit_completion(&ctlr->cur_msg_completion); + smp_wmb(); /* Make these available to spi_finalize_current_message() */ + + ret = ctlr->transfer_one_message(ctlr, msg); + if (ret) { + dev_err(&ctlr->dev, + "failed to transfer one message from queue\n"); + return ret; + } + + WRITE_ONCE(ctlr->cur_msg_need_completion, true); + smp_mb(); /* See spi_finalize_current_message()... */ + if (READ_ONCE(ctlr->cur_msg_incomplete)) + wait_for_completion(&ctlr->cur_msg_completion); + + return 0; +} + +/** + * __spi_pump_messages - function which processes spi message queue + * @ctlr: controller to process queue for + * @in_kthread: true if we are in the context of the message pump thread + * + * This function checks if there is any spi message in the queue that + * needs processing and if so call out to the driver to initialize hardware + * and transfer each message. + * + * Note that it is called both from the kthread itself and also from + * inside spi_sync(); the queue extraction handling at the top of the + * function should deal with this safely. + */ +static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread) +{ + struct spi_message *msg; + bool was_busy = false; + unsigned long flags; + int ret; + + /* Take the IO mutex */ + mutex_lock(&ctlr->io_mutex); + + /* Lock queue */ + spin_lock_irqsave(&ctlr->queue_lock, flags); + + /* Make sure we are not already running a message */ + if (ctlr->cur_msg) + goto out_unlock; + + /* Check if the queue is idle */ + if (list_empty(&ctlr->queue) || !ctlr->running) { + if (!ctlr->busy) + goto out_unlock; + + /* Defer any non-atomic teardown to the thread */ + if (!in_kthread) { + if (!ctlr->dummy_rx && !ctlr->dummy_tx && + !ctlr->unprepare_transfer_hardware) { + spi_idle_runtime_pm(ctlr); + ctlr->busy = false; + ctlr->queue_empty = true; + trace_spi_controller_idle(ctlr); + } else { + kthread_queue_work(ctlr->kworker, + &ctlr->pump_messages); + } + goto out_unlock; + } + + ctlr->busy = false; + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + + kfree(ctlr->dummy_rx); + ctlr->dummy_rx = NULL; + kfree(ctlr->dummy_tx); + ctlr->dummy_tx = NULL; + if (ctlr->unprepare_transfer_hardware && + ctlr->unprepare_transfer_hardware(ctlr)) + dev_err(&ctlr->dev, + "failed to unprepare transfer hardware\n"); + spi_idle_runtime_pm(ctlr); + trace_spi_controller_idle(ctlr); + + spin_lock_irqsave(&ctlr->queue_lock, flags); + ctlr->queue_empty = true; + goto out_unlock; + } + + /* Extract head of queue */ + msg = list_first_entry(&ctlr->queue, struct spi_message, queue); + ctlr->cur_msg = msg; + + list_del_init(&msg->queue); + if (ctlr->busy) + was_busy = true; + else + ctlr->busy = true; + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + + ret = __spi_pump_transfer_message(ctlr, msg, was_busy); + kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); + + ctlr->cur_msg = NULL; + ctlr->fallback = false; + + mutex_unlock(&ctlr->io_mutex); + + /* Prod the scheduler in case transfer_one() was busy waiting */ + if (!ret) + cond_resched(); + return; + +out_unlock: + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + mutex_unlock(&ctlr->io_mutex); +} + +/** + * spi_pump_messages - kthread work function which processes spi message queue + * @work: pointer to kthread work struct contained in the controller struct + */ +static void spi_pump_messages(struct kthread_work *work) +{ + struct spi_controller *ctlr = + container_of(work, struct spi_controller, pump_messages); + + __spi_pump_messages(ctlr, true); +} + +/** + * spi_take_timestamp_pre - helper to collect the beginning of the TX timestamp + * @ctlr: Pointer to the spi_controller structure of the driver + * @xfer: Pointer to the transfer being timestamped + * @progress: How many words (not bytes) have been transferred so far + * @irqs_off: If true, will disable IRQs and preemption for the duration of the + * transfer, for less jitter in time measurement. Only compatible + * with PIO drivers. If true, must follow up with + * spi_take_timestamp_post or otherwise system will crash. + * WARNING: for fully predictable results, the CPU frequency must + * also be under control (governor). + * + * This is a helper for drivers to collect the beginning of the TX timestamp + * for the requested byte from the SPI transfer. The frequency with which this + * function must be called (once per word, once for the whole transfer, once + * per batch of words etc) is arbitrary as long as the @tx buffer offset is + * greater than or equal to the requested byte at the time of the call. The + * timestamp is only taken once, at the first such call. It is assumed that + * the driver advances its @tx buffer pointer monotonically. + */ +void spi_take_timestamp_pre(struct spi_controller *ctlr, + struct spi_transfer *xfer, + size_t progress, bool irqs_off) +{ + if (!xfer->ptp_sts) + return; + + if (xfer->timestamped) + return; + + if (progress > xfer->ptp_sts_word_pre) + return; + + /* Capture the resolution of the timestamp */ + xfer->ptp_sts_word_pre = progress; + + if (irqs_off) { + local_irq_save(ctlr->irq_flags); + preempt_disable(); + } + + ptp_read_system_prets(xfer->ptp_sts); +} +EXPORT_SYMBOL_GPL(spi_take_timestamp_pre); + +/** + * spi_take_timestamp_post - helper to collect the end of the TX timestamp + * @ctlr: Pointer to the spi_controller structure of the driver + * @xfer: Pointer to the transfer being timestamped + * @progress: How many words (not bytes) have been transferred so far + * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU. + * + * This is a helper for drivers to collect the end of the TX timestamp for + * the requested byte from the SPI transfer. Can be called with an arbitrary + * frequency: only the first call where @tx exceeds or is equal to the + * requested word will be timestamped. + */ +void spi_take_timestamp_post(struct spi_controller *ctlr, + struct spi_transfer *xfer, + size_t progress, bool irqs_off) +{ + if (!xfer->ptp_sts) + return; + + if (xfer->timestamped) + return; + + if (progress < xfer->ptp_sts_word_post) + return; + + ptp_read_system_postts(xfer->ptp_sts); + + if (irqs_off) { + local_irq_restore(ctlr->irq_flags); + preempt_enable(); + } + + /* Capture the resolution of the timestamp */ + xfer->ptp_sts_word_post = progress; + + xfer->timestamped = true; +} +EXPORT_SYMBOL_GPL(spi_take_timestamp_post); + +/** + * spi_set_thread_rt - set the controller to pump at realtime priority + * @ctlr: controller to boost priority of + * + * This can be called because the controller requested realtime priority + * (by setting the ->rt value before calling spi_register_controller()) or + * because a device on the bus said that its transfers needed realtime + * priority. + * + * NOTE: at the moment if any device on a bus says it needs realtime then + * the thread will be at realtime priority for all transfers on that + * controller. If this eventually becomes a problem we may see if we can + * find a way to boost the priority only temporarily during relevant + * transfers. + */ +static void spi_set_thread_rt(struct spi_controller *ctlr) +{ + dev_info(&ctlr->dev, + "will run message pump with realtime priority\n"); + sched_set_fifo(ctlr->kworker->task); +} + +static int spi_init_queue(struct spi_controller *ctlr) +{ + ctlr->running = false; + ctlr->busy = false; + ctlr->queue_empty = true; + + ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev)); + if (IS_ERR(ctlr->kworker)) { + dev_err(&ctlr->dev, "failed to create message pump kworker\n"); + return PTR_ERR(ctlr->kworker); + } + + kthread_init_work(&ctlr->pump_messages, spi_pump_messages); + + /* + * Controller config will indicate if this controller should run the + * message pump with high (realtime) priority to reduce the transfer + * latency on the bus by minimising the delay between a transfer + * request and the scheduling of the message pump thread. Without this + * setting the message pump thread will remain at default priority. + */ + if (ctlr->rt) + spi_set_thread_rt(ctlr); + + return 0; +} + +/** + * spi_get_next_queued_message() - called by driver to check for queued + * messages + * @ctlr: the controller to check for queued messages + * + * If there are more messages in the queue, the next message is returned from + * this call. + * + * Return: the next message in the queue, else NULL if the queue is empty. + */ +struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr) +{ + struct spi_message *next; + unsigned long flags; + + /* Get a pointer to the next message, if any */ + spin_lock_irqsave(&ctlr->queue_lock, flags); + next = list_first_entry_or_null(&ctlr->queue, struct spi_message, + queue); + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + + return next; +} +EXPORT_SYMBOL_GPL(spi_get_next_queued_message); + +/** + * spi_finalize_current_message() - the current message is complete + * @ctlr: the controller to return the message to + * + * Called by the driver to notify the core that the message in the front of the + * queue is complete and can be removed from the queue. + */ +void spi_finalize_current_message(struct spi_controller *ctlr) +{ + struct spi_transfer *xfer; + struct spi_message *mesg; + int ret; + + mesg = ctlr->cur_msg; + + if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) { + list_for_each_entry(xfer, &mesg->transfers, transfer_list) { + ptp_read_system_postts(xfer->ptp_sts); + xfer->ptp_sts_word_post = xfer->len; + } + } + + if (unlikely(ctlr->ptp_sts_supported)) + list_for_each_entry(xfer, &mesg->transfers, transfer_list) + WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped); + + spi_unmap_msg(ctlr, mesg); + + /* + * In the prepare_messages callback the SPI bus has the opportunity + * to split a transfer to smaller chunks. + * + * Release the split transfers here since spi_map_msg() is done on + * the split transfers. + */ + spi_res_release(ctlr, mesg); + + if (mesg->prepared && ctlr->unprepare_message) { + ret = ctlr->unprepare_message(ctlr, mesg); + if (ret) { + dev_err(&ctlr->dev, "failed to unprepare message: %d\n", + ret); + } + } + + mesg->prepared = false; + + WRITE_ONCE(ctlr->cur_msg_incomplete, false); + smp_mb(); /* See __spi_pump_transfer_message()... */ + if (READ_ONCE(ctlr->cur_msg_need_completion)) + complete(&ctlr->cur_msg_completion); + + trace_spi_message_done(mesg); + + mesg->state = NULL; + if (mesg->complete) + mesg->complete(mesg->context); +} +EXPORT_SYMBOL_GPL(spi_finalize_current_message); + +static int spi_start_queue(struct spi_controller *ctlr) +{ + unsigned long flags; + + spin_lock_irqsave(&ctlr->queue_lock, flags); + + if (ctlr->running || ctlr->busy) { + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + return -EBUSY; + } + + ctlr->running = true; + ctlr->cur_msg = NULL; + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + + kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); + + return 0; +} + +static int spi_stop_queue(struct spi_controller *ctlr) +{ + unsigned long flags; + unsigned limit = 500; + int ret = 0; + + spin_lock_irqsave(&ctlr->queue_lock, flags); + + /* + * This is a bit lame, but is optimized for the common execution path. + * A wait_queue on the ctlr->busy could be used, but then the common + * execution path (pump_messages) would be required to call wake_up or + * friends on every SPI message. Do this instead. + */ + while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) { + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + usleep_range(10000, 11000); + spin_lock_irqsave(&ctlr->queue_lock, flags); + } + + if (!list_empty(&ctlr->queue) || ctlr->busy) + ret = -EBUSY; + else + ctlr->running = false; + + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + + if (ret) { + dev_warn(&ctlr->dev, "could not stop message queue\n"); + return ret; + } + return ret; +} + +static int spi_destroy_queue(struct spi_controller *ctlr) +{ + int ret; + + ret = spi_stop_queue(ctlr); + + /* + * kthread_flush_worker will block until all work is done. + * If the reason that stop_queue timed out is that the work will never + * finish, then it does no good to call flush/stop thread, so + * return anyway. + */ + if (ret) { + dev_err(&ctlr->dev, "problem destroying queue\n"); + return ret; + } + + kthread_destroy_worker(ctlr->kworker); + + return 0; +} + +static int __spi_queued_transfer(struct spi_device *spi, + struct spi_message *msg, + bool need_pump) +{ + struct spi_controller *ctlr = spi->controller; + unsigned long flags; + + spin_lock_irqsave(&ctlr->queue_lock, flags); + + if (!ctlr->running) { + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + return -ESHUTDOWN; + } + msg->actual_length = 0; + msg->status = -EINPROGRESS; + + list_add_tail(&msg->queue, &ctlr->queue); + ctlr->queue_empty = false; + if (!ctlr->busy && need_pump) + kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); + + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + return 0; +} + +/** + * spi_queued_transfer - transfer function for queued transfers + * @spi: spi device which is requesting transfer + * @msg: spi message which is to handled is queued to driver queue + * + * Return: zero on success, else a negative error code. + */ +static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg) +{ + return __spi_queued_transfer(spi, msg, true); +} + +static int spi_controller_initialize_queue(struct spi_controller *ctlr) +{ + int ret; + + ctlr->transfer = spi_queued_transfer; + if (!ctlr->transfer_one_message) + ctlr->transfer_one_message = spi_transfer_one_message; + + /* Initialize and start queue */ + ret = spi_init_queue(ctlr); + if (ret) { + dev_err(&ctlr->dev, "problem initializing queue\n"); + goto err_init_queue; + } + ctlr->queued = true; + ret = spi_start_queue(ctlr); + if (ret) { + dev_err(&ctlr->dev, "problem starting queue\n"); + goto err_start_queue; + } + + return 0; + +err_start_queue: + spi_destroy_queue(ctlr); +err_init_queue: + return ret; +} + +/** + * spi_flush_queue - Send all pending messages in the queue from the callers' + * context + * @ctlr: controller to process queue for + * + * This should be used when one wants to ensure all pending messages have been + * sent before doing something. Is used by the spi-mem code to make sure SPI + * memory operations do not preempt regular SPI transfers that have been queued + * before the spi-mem operation. + */ +void spi_flush_queue(struct spi_controller *ctlr) +{ + if (ctlr->transfer == spi_queued_transfer) + __spi_pump_messages(ctlr, false); +} + +/*-------------------------------------------------------------------------*/ + +#if defined(CONFIG_OF) +static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi, + struct device_node *nc) +{ + u32 value; + int rc; + + /* Mode (clock phase/polarity/etc.) */ + if (of_property_read_bool(nc, "spi-cpha")) + spi->mode |= SPI_CPHA; + if (of_property_read_bool(nc, "spi-cpol")) + spi->mode |= SPI_CPOL; + if (of_property_read_bool(nc, "spi-3wire")) + spi->mode |= SPI_3WIRE; + if (of_property_read_bool(nc, "spi-lsb-first")) + spi->mode |= SPI_LSB_FIRST; + if (of_property_read_bool(nc, "spi-cs-high")) + spi->mode |= SPI_CS_HIGH; + + /* Device DUAL/QUAD mode */ + if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { + switch (value) { + case 0: + spi->mode |= SPI_NO_TX; + break; + case 1: + break; + case 2: + spi->mode |= SPI_TX_DUAL; + break; + case 4: + spi->mode |= SPI_TX_QUAD; + break; + case 8: + spi->mode |= SPI_TX_OCTAL; + break; + default: + dev_warn(&ctlr->dev, + "spi-tx-bus-width %d not supported\n", + value); + break; + } + } + + if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { + switch (value) { + case 0: + spi->mode |= SPI_NO_RX; + break; + case 1: + break; + case 2: + spi->mode |= SPI_RX_DUAL; + break; + case 4: + spi->mode |= SPI_RX_QUAD; + break; + case 8: + spi->mode |= SPI_RX_OCTAL; + break; + default: + dev_warn(&ctlr->dev, + "spi-rx-bus-width %d not supported\n", + value); + break; + } + } + + if (spi_controller_is_slave(ctlr)) { + if (!of_node_name_eq(nc, "slave")) { + dev_err(&ctlr->dev, "%pOF is not called 'slave'\n", + nc); + return -EINVAL; + } + return 0; + } + + /* Device address */ + rc = of_property_read_u32(nc, "reg", &value); + if (rc) { + dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n", + nc, rc); + return rc; + } + spi_set_chipselect(spi, 0, value); + + /* Device speed */ + if (!of_property_read_u32(nc, "spi-max-frequency", &value)) + spi->max_speed_hz = value; + + return 0; +} + +static struct spi_device * +of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc) +{ + struct spi_device *spi; + int rc; + + /* Alloc an spi_device */ + spi = spi_alloc_device(ctlr); + if (!spi) { + dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc); + rc = -ENOMEM; + goto err_out; + } + + /* Select device driver */ + rc = of_modalias_node(nc, spi->modalias, + sizeof(spi->modalias)); + if (rc < 0) { + dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc); + goto err_out; + } + + rc = of_spi_parse_dt(ctlr, spi, nc); + if (rc) + goto err_out; + + /* Store a pointer to the node in the device structure */ + of_node_get(nc); + spi->dev.of_node = nc; + spi->dev.fwnode = of_fwnode_handle(nc); + + /* Register the new device */ + rc = spi_add_device(spi); + if (rc) { + dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc); + goto err_of_node_put; + } + + return spi; + +err_of_node_put: + of_node_put(nc); +err_out: + spi_dev_put(spi); + return ERR_PTR(rc); +} + +/** + * of_register_spi_devices() - Register child devices onto the SPI bus + * @ctlr: Pointer to spi_controller device + * + * Registers an spi_device for each child node of controller node which + * represents a valid SPI slave. + */ +static void of_register_spi_devices(struct spi_controller *ctlr) +{ + struct spi_device *spi; + struct device_node *nc; + + if (!ctlr->dev.of_node) + return; + + for_each_available_child_of_node(ctlr->dev.of_node, nc) { + if (of_node_test_and_set_flag(nc, OF_POPULATED)) + continue; + spi = of_register_spi_device(ctlr, nc); + if (IS_ERR(spi)) { + dev_warn(&ctlr->dev, + "Failed to create SPI device for %pOF\n", nc); + of_node_clear_flag(nc, OF_POPULATED); + } + } +} +#else +static void of_register_spi_devices(struct spi_controller *ctlr) { } +#endif + +/** + * spi_new_ancillary_device() - Register ancillary SPI device + * @spi: Pointer to the main SPI device registering the ancillary device + * @chip_select: Chip Select of the ancillary device + * + * Register an ancillary SPI device; for example some chips have a chip-select + * for normal device usage and another one for setup/firmware upload. + * + * This may only be called from main SPI device's probe routine. + * + * Return: 0 on success; negative errno on failure + */ +struct spi_device *spi_new_ancillary_device(struct spi_device *spi, + u8 chip_select) +{ + struct spi_device *ancillary; + int rc = 0; + + /* Alloc an spi_device */ + ancillary = spi_alloc_device(spi->controller); + if (!ancillary) { + rc = -ENOMEM; + goto err_out; + } + + strscpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias)); + + /* Use provided chip-select for ancillary device */ + spi_set_chipselect(ancillary, 0, chip_select); + + /* Take over SPI mode/speed from SPI main device */ + ancillary->max_speed_hz = spi->max_speed_hz; + ancillary->mode = spi->mode; + + /* Register the new device */ + rc = spi_add_device_locked(ancillary); + if (rc) { + dev_err(&spi->dev, "failed to register ancillary device\n"); + goto err_out; + } + + return ancillary; + +err_out: + spi_dev_put(ancillary); + return ERR_PTR(rc); +} +EXPORT_SYMBOL_GPL(spi_new_ancillary_device); + +#ifdef CONFIG_ACPI +struct acpi_spi_lookup { + struct spi_controller *ctlr; + u32 max_speed_hz; + u32 mode; + int irq; + u8 bits_per_word; + u8 chip_select; + int n; + int index; +}; + +static int acpi_spi_count(struct acpi_resource *ares, void *data) +{ + struct acpi_resource_spi_serialbus *sb; + int *count = data; + + if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) + return 1; + + sb = &ares->data.spi_serial_bus; + if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_SPI) + return 1; + + *count = *count + 1; + + return 1; +} + +/** + * acpi_spi_count_resources - Count the number of SpiSerialBus resources + * @adev: ACPI device + * + * Returns the number of SpiSerialBus resources in the ACPI-device's + * resource-list; or a negative error code. + */ +int acpi_spi_count_resources(struct acpi_device *adev) +{ + LIST_HEAD(r); + int count = 0; + int ret; + + ret = acpi_dev_get_resources(adev, &r, acpi_spi_count, &count); + if (ret < 0) + return ret; + + acpi_dev_free_resource_list(&r); + + return count; +} +EXPORT_SYMBOL_GPL(acpi_spi_count_resources); + +static void acpi_spi_parse_apple_properties(struct acpi_device *dev, + struct acpi_spi_lookup *lookup) +{ + const union acpi_object *obj; + + if (!x86_apple_machine) + return; + + if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj) + && obj->buffer.length >= 4) + lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer; + + if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj) + && obj->buffer.length == 8) + lookup->bits_per_word = *(u64 *)obj->buffer.pointer; + + if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj) + && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer) + lookup->mode |= SPI_LSB_FIRST; + + if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj) + && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) + lookup->mode |= SPI_CPOL; + + if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj) + && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) + lookup->mode |= SPI_CPHA; +} + +static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev); + +static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) +{ + struct acpi_spi_lookup *lookup = data; + struct spi_controller *ctlr = lookup->ctlr; + + if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { + struct acpi_resource_spi_serialbus *sb; + acpi_handle parent_handle; + acpi_status status; + + sb = &ares->data.spi_serial_bus; + if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { + + if (lookup->index != -1 && lookup->n++ != lookup->index) + return 1; + + status = acpi_get_handle(NULL, + sb->resource_source.string_ptr, + &parent_handle); + + if (ACPI_FAILURE(status)) + return -ENODEV; + + if (ctlr) { + if (ACPI_HANDLE(ctlr->dev.parent) != parent_handle) + return -ENODEV; + } else { + struct acpi_device *adev; + + adev = acpi_fetch_acpi_dev(parent_handle); + if (!adev) + return -ENODEV; + + ctlr = acpi_spi_find_controller_by_adev(adev); + if (!ctlr) + return -EPROBE_DEFER; + + lookup->ctlr = ctlr; + } + + /* + * ACPI DeviceSelection numbering is handled by the + * host controller driver in Windows and can vary + * from driver to driver. In Linux we always expect + * 0 .. max - 1 so we need to ask the driver to + * translate between the two schemes. + */ + if (ctlr->fw_translate_cs) { + int cs = ctlr->fw_translate_cs(ctlr, + sb->device_selection); + if (cs < 0) + return cs; + lookup->chip_select = cs; + } else { + lookup->chip_select = sb->device_selection; + } + + lookup->max_speed_hz = sb->connection_speed; + lookup->bits_per_word = sb->data_bit_length; + + if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) + lookup->mode |= SPI_CPHA; + if (sb->clock_polarity == ACPI_SPI_START_HIGH) + lookup->mode |= SPI_CPOL; + if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) + lookup->mode |= SPI_CS_HIGH; + } + } else if (lookup->irq < 0) { + struct resource r; + + if (acpi_dev_resource_interrupt(ares, 0, &r)) + lookup->irq = r.start; + } + + /* Always tell the ACPI core to skip this resource */ + return 1; +} + +/** + * acpi_spi_device_alloc - Allocate a spi device, and fill it in with ACPI information + * @ctlr: controller to which the spi device belongs + * @adev: ACPI Device for the spi device + * @index: Index of the spi resource inside the ACPI Node + * + * This should be used to allocate a new spi device from and ACPI Node. + * The caller is responsible for calling spi_add_device to register the spi device. + * + * If ctlr is set to NULL, the Controller for the spi device will be looked up + * using the resource. + * If index is set to -1, index is not used. + * Note: If index is -1, ctlr must be set. + * + * Return: a pointer to the new device, or ERR_PTR on error. + */ +struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr, + struct acpi_device *adev, + int index) +{ + acpi_handle parent_handle = NULL; + struct list_head resource_list; + struct acpi_spi_lookup lookup = {}; + struct spi_device *spi; + int ret; + + if (!ctlr && index == -1) + return ERR_PTR(-EINVAL); + + lookup.ctlr = ctlr; + lookup.irq = -1; + lookup.index = index; + lookup.n = 0; + + INIT_LIST_HEAD(&resource_list); + ret = acpi_dev_get_resources(adev, &resource_list, + acpi_spi_add_resource, &lookup); + acpi_dev_free_resource_list(&resource_list); + + if (ret < 0) + /* Found SPI in _CRS but it points to another controller */ + return ERR_PTR(ret); + + if (!lookup.max_speed_hz && + ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) && + ACPI_HANDLE(lookup.ctlr->dev.parent) == parent_handle) { + /* Apple does not use _CRS but nested devices for SPI slaves */ + acpi_spi_parse_apple_properties(adev, &lookup); + } + + if (!lookup.max_speed_hz) + return ERR_PTR(-ENODEV); + + spi = spi_alloc_device(lookup.ctlr); + if (!spi) { + dev_err(&lookup.ctlr->dev, "failed to allocate SPI device for %s\n", + dev_name(&adev->dev)); + return ERR_PTR(-ENOMEM); + } + + ACPI_COMPANION_SET(&spi->dev, adev); + spi->max_speed_hz = lookup.max_speed_hz; + spi->mode |= lookup.mode; + spi->irq = lookup.irq; + spi->bits_per_word = lookup.bits_per_word; + spi_set_chipselect(spi, 0, lookup.chip_select); + + return spi; +} +EXPORT_SYMBOL_GPL(acpi_spi_device_alloc); + +static acpi_status acpi_register_spi_device(struct spi_controller *ctlr, + struct acpi_device *adev) +{ + struct spi_device *spi; + + if (acpi_bus_get_status(adev) || !adev->status.present || + acpi_device_enumerated(adev)) + return AE_OK; + + spi = acpi_spi_device_alloc(ctlr, adev, -1); + if (IS_ERR(spi)) { + if (PTR_ERR(spi) == -ENOMEM) + return AE_NO_MEMORY; + else + return AE_OK; + } + + acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias, + sizeof(spi->modalias)); + + if (spi->irq < 0) + spi->irq = acpi_dev_gpio_irq_get(adev, 0); + + acpi_device_set_enumerated(adev); + + adev->power.flags.ignore_parent = true; + if (spi_add_device(spi)) { + adev->power.flags.ignore_parent = false; + dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n", + dev_name(&adev->dev)); + spi_dev_put(spi); + } + + return AE_OK; +} + +static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, + void *data, void **return_value) +{ + struct acpi_device *adev = acpi_fetch_acpi_dev(handle); + struct spi_controller *ctlr = data; + + if (!adev) + return AE_OK; + + return acpi_register_spi_device(ctlr, adev); +} + +#define SPI_ACPI_ENUMERATE_MAX_DEPTH 32 + +static void acpi_register_spi_devices(struct spi_controller *ctlr) +{ + acpi_status status; + acpi_handle handle; + + handle = ACPI_HANDLE(ctlr->dev.parent); + if (!handle) + return; + + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, + SPI_ACPI_ENUMERATE_MAX_DEPTH, + acpi_spi_add_device, NULL, ctlr, NULL); + if (ACPI_FAILURE(status)) + dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n"); +} +#else +static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {} +#endif /* CONFIG_ACPI */ + +static void spi_controller_release(struct device *dev) +{ + struct spi_controller *ctlr; + + ctlr = container_of(dev, struct spi_controller, dev); + kfree(ctlr); +} + +static struct class spi_master_class = { + .name = "spi_master", + .owner = THIS_MODULE, + .dev_release = spi_controller_release, + .dev_groups = spi_master_groups, +}; + +#ifdef CONFIG_SPI_SLAVE +/** + * spi_slave_abort - abort the ongoing transfer request on an SPI slave + * controller + * @spi: device used for the current transfer + */ +int spi_slave_abort(struct spi_device *spi) +{ + struct spi_controller *ctlr = spi->controller; + + if (spi_controller_is_slave(ctlr) && ctlr->slave_abort) + return ctlr->slave_abort(ctlr); + + return -ENOTSUPP; +} +EXPORT_SYMBOL_GPL(spi_slave_abort); + +static ssize_t slave_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct spi_controller *ctlr = container_of(dev, struct spi_controller, + dev); + struct device *child; + + child = device_find_any_child(&ctlr->dev); + return sprintf(buf, "%s\n", + child ? to_spi_device(child)->modalias : NULL); +} + +static ssize_t slave_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct spi_controller *ctlr = container_of(dev, struct spi_controller, + dev); + struct spi_device *spi; + struct device *child; + char name[32]; + int rc; + + rc = sscanf(buf, "%31s", name); + if (rc != 1 || !name[0]) + return -EINVAL; + + child = device_find_any_child(&ctlr->dev); + if (child) { + /* Remove registered slave */ + device_unregister(child); + put_device(child); + } + + if (strcmp(name, "(null)")) { + /* Register new slave */ + spi = spi_alloc_device(ctlr); + if (!spi) + return -ENOMEM; + + strscpy(spi->modalias, name, sizeof(spi->modalias)); + + rc = spi_add_device(spi); + if (rc) { + spi_dev_put(spi); + return rc; + } + } + + return count; +} + +static DEVICE_ATTR_RW(slave); + +static struct attribute *spi_slave_attrs[] = { + &dev_attr_slave.attr, + NULL, +}; + +static const struct attribute_group spi_slave_group = { + .attrs = spi_slave_attrs, +}; + +static const struct attribute_group *spi_slave_groups[] = { + &spi_controller_statistics_group, + &spi_slave_group, + NULL, +}; + +static struct class spi_slave_class = { + .name = "spi_slave", + .owner = THIS_MODULE, + .dev_release = spi_controller_release, + .dev_groups = spi_slave_groups, +}; +#else +extern struct class spi_slave_class; /* dummy */ +#endif + +/** + * __spi_alloc_controller - allocate an SPI master or slave controller + * @dev: the controller, possibly using the platform_bus + * @size: how much zeroed driver-private data to allocate; the pointer to this + * memory is in the driver_data field of the returned device, accessible + * with spi_controller_get_devdata(); the memory is cacheline aligned; + * drivers granting DMA access to portions of their private data need to + * round up @size using ALIGN(size, dma_get_cache_alignment()). + * @slave: flag indicating whether to allocate an SPI master (false) or SPI + * slave (true) controller + * Context: can sleep + * + * This call is used only by SPI controller drivers, which are the + * only ones directly touching chip registers. It's how they allocate + * an spi_controller structure, prior to calling spi_register_controller(). + * + * This must be called from context that can sleep. + * + * The caller is responsible for assigning the bus number and initializing the + * controller's methods before calling spi_register_controller(); and (after + * errors adding the device) calling spi_controller_put() to prevent a memory + * leak. + * + * Return: the SPI controller structure on success, else NULL. + */ +struct spi_controller *__spi_alloc_controller(struct device *dev, + unsigned int size, bool slave) +{ + struct spi_controller *ctlr; + size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment()); + + if (!dev) + return NULL; + + ctlr = kzalloc(size + ctlr_size, GFP_KERNEL); + if (!ctlr) + return NULL; + + device_initialize(&ctlr->dev); + INIT_LIST_HEAD(&ctlr->queue); + spin_lock_init(&ctlr->queue_lock); + spin_lock_init(&ctlr->bus_lock_spinlock); + mutex_init(&ctlr->bus_lock_mutex); + mutex_init(&ctlr->io_mutex); + mutex_init(&ctlr->add_lock); + ctlr->bus_num = -1; + ctlr->num_chipselect = 1; + ctlr->slave = slave; + if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave) + ctlr->dev.class = &spi_slave_class; + else + ctlr->dev.class = &spi_master_class; + ctlr->dev.parent = dev; + pm_suspend_ignore_children(&ctlr->dev, true); + spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size); + + return ctlr; +} +EXPORT_SYMBOL_GPL(__spi_alloc_controller); + +static void devm_spi_release_controller(struct device *dev, void *ctlr) +{ + spi_controller_put(*(struct spi_controller **)ctlr); +} + +/** + * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller() + * @dev: physical device of SPI controller + * @size: how much zeroed driver-private data to allocate + * @slave: whether to allocate an SPI master (false) or SPI slave (true) + * Context: can sleep + * + * Allocate an SPI controller and automatically release a reference on it + * when @dev is unbound from its driver. Drivers are thus relieved from + * having to call spi_controller_put(). + * + * The arguments to this function are identical to __spi_alloc_controller(). + * + * Return: the SPI controller structure on success, else NULL. + */ +struct spi_controller *__devm_spi_alloc_controller(struct device *dev, + unsigned int size, + bool slave) +{ + struct spi_controller **ptr, *ctlr; + + ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr), + GFP_KERNEL); + if (!ptr) + return NULL; + + ctlr = __spi_alloc_controller(dev, size, slave); + if (ctlr) { + ctlr->devm_allocated = true; + *ptr = ctlr; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return ctlr; +} +EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller); + +/** + * spi_get_gpio_descs() - grab chip select GPIOs for the master + * @ctlr: The SPI master to grab GPIO descriptors for + */ +static int spi_get_gpio_descs(struct spi_controller *ctlr) +{ + int nb, i; + struct gpio_desc **cs; + struct device *dev = &ctlr->dev; + unsigned long native_cs_mask = 0; + unsigned int num_cs_gpios = 0; + + nb = gpiod_count(dev, "cs"); + if (nb < 0) { + /* No GPIOs at all is fine, else return the error */ + if (nb == -ENOENT) + return 0; + return nb; + } + + ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect); + + cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs), + GFP_KERNEL); + if (!cs) + return -ENOMEM; + ctlr->cs_gpiods = cs; + + for (i = 0; i < nb; i++) { + /* + * Most chipselects are active low, the inverted + * semantics are handled by special quirks in gpiolib, + * so initializing them GPIOD_OUT_LOW here means + * "unasserted", in most cases this will drive the physical + * line high. + */ + cs[i] = devm_gpiod_get_index_optional(dev, "cs", i, + GPIOD_OUT_LOW); + if (IS_ERR(cs[i])) + return PTR_ERR(cs[i]); + + if (cs[i]) { + /* + * If we find a CS GPIO, name it after the device and + * chip select line. + */ + char *gpioname; + + gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d", + dev_name(dev), i); + if (!gpioname) + return -ENOMEM; + gpiod_set_consumer_name(cs[i], gpioname); + num_cs_gpios++; + continue; + } + + if (ctlr->max_native_cs && i >= ctlr->max_native_cs) { + dev_err(dev, "Invalid native chip select %d\n", i); + return -EINVAL; + } + native_cs_mask |= BIT(i); + } + + ctlr->unused_native_cs = ffs(~native_cs_mask) - 1; + + if ((ctlr->flags & SPI_MASTER_GPIO_SS) && num_cs_gpios && + ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) { + dev_err(dev, "No unused native chip select available\n"); + return -EINVAL; + } + + return 0; +} + +static int spi_controller_check_ops(struct spi_controller *ctlr) +{ + /* + * The controller may implement only the high-level SPI-memory like + * operations if it does not support regular SPI transfers, and this is + * valid use case. + * If ->mem_ops is NULL, we request that at least one of the + * ->transfer_xxx() method be implemented. + */ + if (ctlr->mem_ops) { + if (!ctlr->mem_ops->exec_op) + return -EINVAL; + } else if (!ctlr->transfer && !ctlr->transfer_one && + !ctlr->transfer_one_message) { + return -EINVAL; + } + + return 0; +} + +/** + * spi_register_controller - register SPI master or slave controller + * @ctlr: initialized master, originally from spi_alloc_master() or + * spi_alloc_slave() + * Context: can sleep + * + * SPI controllers connect to their drivers using some non-SPI bus, + * such as the platform bus. The final stage of probe() in that code + * includes calling spi_register_controller() to hook up to this SPI bus glue. + * + * SPI controllers use board specific (often SOC specific) bus numbers, + * and board-specific addressing for SPI devices combines those numbers + * with chip select numbers. Since SPI does not directly support dynamic + * device identification, boards need configuration tables telling which + * chip is at which address. + * + * This must be called from context that can sleep. It returns zero on + * success, else a negative error code (dropping the controller's refcount). + * After a successful return, the caller is responsible for calling + * spi_unregister_controller(). + * + * Return: zero on success, else a negative error code. + */ +int spi_register_controller(struct spi_controller *ctlr) +{ + struct device *dev = ctlr->dev.parent; + struct boardinfo *bi; + int status; + int id, first_dynamic; + + if (!dev) + return -ENODEV; + + /* + * Make sure all necessary hooks are implemented before registering + * the SPI controller. + */ + status = spi_controller_check_ops(ctlr); + if (status) + return status; + + if (ctlr->bus_num >= 0) { + /* Devices with a fixed bus num must check-in with the num */ + mutex_lock(&board_lock); + id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num, + ctlr->bus_num + 1, GFP_KERNEL); + mutex_unlock(&board_lock); + if (WARN(id < 0, "couldn't get idr")) + return id == -ENOSPC ? -EBUSY : id; + ctlr->bus_num = id; + } else if (ctlr->dev.of_node) { + /* Allocate dynamic bus number using Linux idr */ + id = of_alias_get_id(ctlr->dev.of_node, "spi"); + if (id >= 0) { + ctlr->bus_num = id; + mutex_lock(&board_lock); + id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num, + ctlr->bus_num + 1, GFP_KERNEL); + mutex_unlock(&board_lock); + if (WARN(id < 0, "couldn't get idr")) + return id == -ENOSPC ? -EBUSY : id; + } + } + if (ctlr->bus_num < 0) { + first_dynamic = of_alias_get_highest_id("spi"); + if (first_dynamic < 0) + first_dynamic = 0; + else + first_dynamic++; + + mutex_lock(&board_lock); + id = idr_alloc(&spi_master_idr, ctlr, first_dynamic, + 0, GFP_KERNEL); + mutex_unlock(&board_lock); + if (WARN(id < 0, "couldn't get idr")) + return id; + ctlr->bus_num = id; + } + ctlr->bus_lock_flag = 0; + init_completion(&ctlr->xfer_completion); + init_completion(&ctlr->cur_msg_completion); + if (!ctlr->max_dma_len) + ctlr->max_dma_len = INT_MAX; + + /* + * Register the device, then userspace will see it. + * Registration fails if the bus ID is in use. + */ + dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num); + + if (!spi_controller_is_slave(ctlr) && ctlr->use_gpio_descriptors) { + status = spi_get_gpio_descs(ctlr); + if (status) + goto free_bus_id; + /* + * A controller using GPIO descriptors always + * supports SPI_CS_HIGH if need be. + */ + ctlr->mode_bits |= SPI_CS_HIGH; + } + + /* + * Even if it's just one always-selected device, there must + * be at least one chipselect. + */ + if (!ctlr->num_chipselect) { + status = -EINVAL; + goto free_bus_id; + } + + /* Setting last_cs to -1 means no chip selected */ + ctlr->last_cs = -1; + + status = device_add(&ctlr->dev); + if (status < 0) + goto free_bus_id; + dev_dbg(dev, "registered %s %s\n", + spi_controller_is_slave(ctlr) ? "slave" : "master", + dev_name(&ctlr->dev)); + + /* + * If we're using a queued driver, start the queue. Note that we don't + * need the queueing logic if the driver is only supporting high-level + * memory operations. + */ + if (ctlr->transfer) { + dev_info(dev, "controller is unqueued, this is deprecated\n"); + } else if (ctlr->transfer_one || ctlr->transfer_one_message) { + status = spi_controller_initialize_queue(ctlr); + if (status) { + device_del(&ctlr->dev); + goto free_bus_id; + } + } + /* Add statistics */ + ctlr->pcpu_statistics = spi_alloc_pcpu_stats(dev); + if (!ctlr->pcpu_statistics) { + dev_err(dev, "Error allocating per-cpu statistics\n"); + status = -ENOMEM; + goto destroy_queue; + } + + mutex_lock(&board_lock); + list_add_tail(&ctlr->list, &spi_controller_list); + list_for_each_entry(bi, &board_list, list) + spi_match_controller_to_boardinfo(ctlr, &bi->board_info); + mutex_unlock(&board_lock); + + /* Register devices from the device tree and ACPI */ + of_register_spi_devices(ctlr); + acpi_register_spi_devices(ctlr); + return status; + +destroy_queue: + spi_destroy_queue(ctlr); +free_bus_id: + mutex_lock(&board_lock); + idr_remove(&spi_master_idr, ctlr->bus_num); + mutex_unlock(&board_lock); + return status; +} +EXPORT_SYMBOL_GPL(spi_register_controller); + +static void devm_spi_unregister(struct device *dev, void *res) +{ + spi_unregister_controller(*(struct spi_controller **)res); +} + +/** + * devm_spi_register_controller - register managed SPI master or slave + * controller + * @dev: device managing SPI controller + * @ctlr: initialized controller, originally from spi_alloc_master() or + * spi_alloc_slave() + * Context: can sleep + * + * Register a SPI device as with spi_register_controller() which will + * automatically be unregistered and freed. + * + * Return: zero on success, else a negative error code. + */ +int devm_spi_register_controller(struct device *dev, + struct spi_controller *ctlr) +{ + struct spi_controller **ptr; + int ret; + + ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return -ENOMEM; + + ret = spi_register_controller(ctlr); + if (!ret) { + *ptr = ctlr; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return ret; +} +EXPORT_SYMBOL_GPL(devm_spi_register_controller); + +static int __unregister(struct device *dev, void *null) +{ + spi_unregister_device(to_spi_device(dev)); + return 0; +} + +/** + * spi_unregister_controller - unregister SPI master or slave controller + * @ctlr: the controller being unregistered + * Context: can sleep + * + * This call is used only by SPI controller drivers, which are the + * only ones directly touching chip registers. + * + * This must be called from context that can sleep. + * + * Note that this function also drops a reference to the controller. + */ +void spi_unregister_controller(struct spi_controller *ctlr) +{ + struct spi_controller *found; + int id = ctlr->bus_num; + + /* Prevent addition of new devices, unregister existing ones */ + if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) + mutex_lock(&ctlr->add_lock); + + device_for_each_child(&ctlr->dev, NULL, __unregister); + + /* First make sure that this controller was ever added */ + mutex_lock(&board_lock); + found = idr_find(&spi_master_idr, id); + mutex_unlock(&board_lock); + if (ctlr->queued) { + if (spi_destroy_queue(ctlr)) + dev_err(&ctlr->dev, "queue remove failed\n"); + } + mutex_lock(&board_lock); + list_del(&ctlr->list); + mutex_unlock(&board_lock); + + device_del(&ctlr->dev); + + /* Free bus id */ + mutex_lock(&board_lock); + if (found == ctlr) + idr_remove(&spi_master_idr, id); + mutex_unlock(&board_lock); + + if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) + mutex_unlock(&ctlr->add_lock); + + /* Release the last reference on the controller if its driver + * has not yet been converted to devm_spi_alloc_master/slave(). + */ + if (!ctlr->devm_allocated) + put_device(&ctlr->dev); +} +EXPORT_SYMBOL_GPL(spi_unregister_controller); + +static inline int __spi_check_suspended(const struct spi_controller *ctlr) +{ + return ctlr->flags & SPI_CONTROLLER_SUSPENDED ? -ESHUTDOWN : 0; +} + +static inline void __spi_mark_suspended(struct spi_controller *ctlr) +{ + mutex_lock(&ctlr->bus_lock_mutex); + ctlr->flags |= SPI_CONTROLLER_SUSPENDED; + mutex_unlock(&ctlr->bus_lock_mutex); +} + +static inline void __spi_mark_resumed(struct spi_controller *ctlr) +{ + mutex_lock(&ctlr->bus_lock_mutex); + ctlr->flags &= ~SPI_CONTROLLER_SUSPENDED; + mutex_unlock(&ctlr->bus_lock_mutex); +} + +int spi_controller_suspend(struct spi_controller *ctlr) +{ + int ret = 0; + + /* Basically no-ops for non-queued controllers */ + if (ctlr->queued) { + ret = spi_stop_queue(ctlr); + if (ret) + dev_err(&ctlr->dev, "queue stop failed\n"); + } + + __spi_mark_suspended(ctlr); + return ret; +} +EXPORT_SYMBOL_GPL(spi_controller_suspend); + +int spi_controller_resume(struct spi_controller *ctlr) +{ + int ret = 0; + + __spi_mark_resumed(ctlr); + + if (ctlr->queued) { + ret = spi_start_queue(ctlr); + if (ret) + dev_err(&ctlr->dev, "queue restart failed\n"); + } + return ret; +} +EXPORT_SYMBOL_GPL(spi_controller_resume); + +/*-------------------------------------------------------------------------*/ + +/* Core methods for spi_message alterations */ + +static void __spi_replace_transfers_release(struct spi_controller *ctlr, + struct spi_message *msg, + void *res) +{ + struct spi_replaced_transfers *rxfer = res; + size_t i; + + /* Call extra callback if requested */ + if (rxfer->release) + rxfer->release(ctlr, msg, res); + + /* Insert replaced transfers back into the message */ + list_splice(&rxfer->replaced_transfers, rxfer->replaced_after); + + /* Remove the formerly inserted entries */ + for (i = 0; i < rxfer->inserted; i++) + list_del(&rxfer->inserted_transfers[i].transfer_list); +} + +/** + * spi_replace_transfers - replace transfers with several transfers + * and register change with spi_message.resources + * @msg: the spi_message we work upon + * @xfer_first: the first spi_transfer we want to replace + * @remove: number of transfers to remove + * @insert: the number of transfers we want to insert instead + * @release: extra release code necessary in some circumstances + * @extradatasize: extra data to allocate (with alignment guarantees + * of struct @spi_transfer) + * @gfp: gfp flags + * + * Returns: pointer to @spi_replaced_transfers, + * PTR_ERR(...) in case of errors. + */ +static struct spi_replaced_transfers *spi_replace_transfers( + struct spi_message *msg, + struct spi_transfer *xfer_first, + size_t remove, + size_t insert, + spi_replaced_release_t release, + size_t extradatasize, + gfp_t gfp) +{ + struct spi_replaced_transfers *rxfer; + struct spi_transfer *xfer; + size_t i; + + /* Allocate the structure using spi_res */ + rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release, + struct_size(rxfer, inserted_transfers, insert) + + extradatasize, + gfp); + if (!rxfer) + return ERR_PTR(-ENOMEM); + + /* The release code to invoke before running the generic release */ + rxfer->release = release; + + /* Assign extradata */ + if (extradatasize) + rxfer->extradata = + &rxfer->inserted_transfers[insert]; + + /* Init the replaced_transfers list */ + INIT_LIST_HEAD(&rxfer->replaced_transfers); + + /* + * Assign the list_entry after which we should reinsert + * the @replaced_transfers - it may be spi_message.messages! + */ + rxfer->replaced_after = xfer_first->transfer_list.prev; + + /* Remove the requested number of transfers */ + for (i = 0; i < remove; i++) { + /* + * If the entry after replaced_after it is msg->transfers + * then we have been requested to remove more transfers + * than are in the list. + */ + if (rxfer->replaced_after->next == &msg->transfers) { + dev_err(&msg->spi->dev, + "requested to remove more spi_transfers than are available\n"); + /* Insert replaced transfers back into the message */ + list_splice(&rxfer->replaced_transfers, + rxfer->replaced_after); + + /* Free the spi_replace_transfer structure... */ + spi_res_free(rxfer); + + /* ...and return with an error */ + return ERR_PTR(-EINVAL); + } + + /* + * Remove the entry after replaced_after from list of + * transfers and add it to list of replaced_transfers. + */ + list_move_tail(rxfer->replaced_after->next, + &rxfer->replaced_transfers); + } + + /* + * Create copy of the given xfer with identical settings + * based on the first transfer to get removed. + */ + for (i = 0; i < insert; i++) { + /* We need to run in reverse order */ + xfer = &rxfer->inserted_transfers[insert - 1 - i]; + + /* Copy all spi_transfer data */ + memcpy(xfer, xfer_first, sizeof(*xfer)); + + /* Add to list */ + list_add(&xfer->transfer_list, rxfer->replaced_after); + + /* Clear cs_change and delay for all but the last */ + if (i) { + xfer->cs_change = false; + xfer->delay.value = 0; + } + } + + /* Set up inserted... */ + rxfer->inserted = insert; + + /* ...and register it with spi_res/spi_message */ + spi_res_add(msg, rxfer); + + return rxfer; +} + +static int __spi_split_transfer_maxsize(struct spi_controller *ctlr, + struct spi_message *msg, + struct spi_transfer **xferp, + size_t maxsize, + gfp_t gfp) +{ + struct spi_transfer *xfer = *xferp, *xfers; + struct spi_replaced_transfers *srt; + size_t offset; + size_t count, i; + + /* Calculate how many we have to replace */ + count = DIV_ROUND_UP(xfer->len, maxsize); + + /* Create replacement */ + srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp); + if (IS_ERR(srt)) + return PTR_ERR(srt); + xfers = srt->inserted_transfers; + + /* + * Now handle each of those newly inserted spi_transfers. + * Note that the replacements spi_transfers all are preset + * to the same values as *xferp, so tx_buf, rx_buf and len + * are all identical (as well as most others) + * so we just have to fix up len and the pointers. + * + * This also includes support for the depreciated + * spi_message.is_dma_mapped interface. + */ + + /* + * The first transfer just needs the length modified, so we + * run it outside the loop. + */ + xfers[0].len = min_t(size_t, maxsize, xfer[0].len); + + /* All the others need rx_buf/tx_buf also set */ + for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) { + /* Update rx_buf, tx_buf and dma */ + if (xfers[i].rx_buf) + xfers[i].rx_buf += offset; + if (xfers[i].rx_dma) + xfers[i].rx_dma += offset; + if (xfers[i].tx_buf) + xfers[i].tx_buf += offset; + if (xfers[i].tx_dma) + xfers[i].tx_dma += offset; + + /* Update length */ + xfers[i].len = min(maxsize, xfers[i].len - offset); + } + + /* + * We set up xferp to the last entry we have inserted, + * so that we skip those already split transfers. + */ + *xferp = &xfers[count - 1]; + + /* Increment statistics counters */ + SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, + transfers_split_maxsize); + SPI_STATISTICS_INCREMENT_FIELD(msg->spi->pcpu_statistics, + transfers_split_maxsize); + + return 0; +} + +/** + * spi_split_transfers_maxsize - split spi transfers into multiple transfers + * when an individual transfer exceeds a + * certain size + * @ctlr: the @spi_controller for this transfer + * @msg: the @spi_message to transform + * @maxsize: the maximum when to apply this + * @gfp: GFP allocation flags + * + * Return: status of transformation + */ +int spi_split_transfers_maxsize(struct spi_controller *ctlr, + struct spi_message *msg, + size_t maxsize, + gfp_t gfp) +{ + struct spi_transfer *xfer; + int ret; + + /* + * Iterate over the transfer_list, + * but note that xfer is advanced to the last transfer inserted + * to avoid checking sizes again unnecessarily (also xfer does + * potentially belong to a different list by the time the + * replacement has happened). + */ + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + if (xfer->len > maxsize) { + ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer, + maxsize, gfp); + if (ret) + return ret; + } + } + + return 0; +} +EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize); + +/*-------------------------------------------------------------------------*/ + +/* Core methods for SPI controller protocol drivers. Some of the + * other core methods are currently defined as inline functions. + */ + +static int __spi_validate_bits_per_word(struct spi_controller *ctlr, + u8 bits_per_word) +{ + if (ctlr->bits_per_word_mask) { + /* Only 32 bits fit in the mask */ + if (bits_per_word > 32) + return -EINVAL; + if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word))) + return -EINVAL; + } + + return 0; +} + +/** + * spi_set_cs_timing - configure CS setup, hold, and inactive delays + * @spi: the device that requires specific CS timing configuration + * + * Return: zero on success, else a negative error code. + */ +static int spi_set_cs_timing(struct spi_device *spi) +{ + struct device *parent = spi->controller->dev.parent; + int status = 0; + + if (spi->controller->set_cs_timing && !spi_get_csgpiod(spi, 0)) { + if (spi->controller->auto_runtime_pm) { + status = pm_runtime_get_sync(parent); + if (status < 0) { + pm_runtime_put_noidle(parent); + dev_err(&spi->controller->dev, "Failed to power device: %d\n", + status); + return status; + } + + status = spi->controller->set_cs_timing(spi); + pm_runtime_mark_last_busy(parent); + pm_runtime_put_autosuspend(parent); + } else { + status = spi->controller->set_cs_timing(spi); + } + } + return status; +} + +/** + * spi_setup - setup SPI mode and clock rate + * @spi: the device whose settings are being modified + * Context: can sleep, and no requests are queued to the device + * + * SPI protocol drivers may need to update the transfer mode if the + * device doesn't work with its default. They may likewise need + * to update clock rates or word sizes from initial values. This function + * changes those settings, and must be called from a context that can sleep. + * Except for SPI_CS_HIGH, which takes effect immediately, the changes take + * effect the next time the device is selected and data is transferred to + * or from it. When this function returns, the spi device is deselected. + * + * Note that this call will fail if the protocol driver specifies an option + * that the underlying controller or its driver does not support. For + * example, not all hardware supports wire transfers using nine bit words, + * LSB-first wire encoding, or active-high chipselects. + * + * Return: zero on success, else a negative error code. + */ +int spi_setup(struct spi_device *spi) +{ + unsigned bad_bits, ugly_bits; + int status = 0; + + /* + * Check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO + * are set at the same time. + */ + if ((hweight_long(spi->mode & + (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) || + (hweight_long(spi->mode & + (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) { + dev_err(&spi->dev, + "setup: can not select any two of dual, quad and no-rx/tx at the same time\n"); + return -EINVAL; + } + /* If it is SPI_3WIRE mode, DUAL and QUAD should be forbidden */ + if ((spi->mode & SPI_3WIRE) && (spi->mode & + (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | + SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL))) + return -EINVAL; + /* + * Help drivers fail *cleanly* when they need options + * that aren't supported with their current controller. + * SPI_CS_WORD has a fallback software implementation, + * so it is ignored here. + */ + bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD | + SPI_NO_TX | SPI_NO_RX); + ugly_bits = bad_bits & + (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | + SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL); + if (ugly_bits) { + dev_warn(&spi->dev, + "setup: ignoring unsupported mode bits %x\n", + ugly_bits); + spi->mode &= ~ugly_bits; + bad_bits &= ~ugly_bits; + } + if (bad_bits) { + dev_err(&spi->dev, "setup: unsupported mode bits %x\n", + bad_bits); + return -EINVAL; + } + + if (!spi->bits_per_word) { + spi->bits_per_word = 8; + } else { + /* + * Some controllers may not support the default 8 bits-per-word + * so only perform the check when this is explicitly provided. + */ + status = __spi_validate_bits_per_word(spi->controller, + spi->bits_per_word); + if (status) + return status; + } + + if (spi->controller->max_speed_hz && + (!spi->max_speed_hz || + spi->max_speed_hz > spi->controller->max_speed_hz)) + spi->max_speed_hz = spi->controller->max_speed_hz; + + mutex_lock(&spi->controller->io_mutex); + + if (spi->controller->setup) { + status = spi->controller->setup(spi); + if (status) { + mutex_unlock(&spi->controller->io_mutex); + dev_err(&spi->controller->dev, "Failed to setup device: %d\n", + status); + return status; + } + } + + status = spi_set_cs_timing(spi); + if (status) { + mutex_unlock(&spi->controller->io_mutex); + return status; + } + + if (spi->controller->auto_runtime_pm && spi->controller->set_cs) { + status = pm_runtime_resume_and_get(spi->controller->dev.parent); + if (status < 0) { + mutex_unlock(&spi->controller->io_mutex); + dev_err(&spi->controller->dev, "Failed to power device: %d\n", + status); + return status; + } + + /* + * We do not want to return positive value from pm_runtime_get, + * there are many instances of devices calling spi_setup() and + * checking for a non-zero return value instead of a negative + * return value. + */ + status = 0; + + spi_set_cs(spi, false, true); + pm_runtime_mark_last_busy(spi->controller->dev.parent); + pm_runtime_put_autosuspend(spi->controller->dev.parent); + } else { + spi_set_cs(spi, false, true); + } + + mutex_unlock(&spi->controller->io_mutex); + + if (spi->rt && !spi->controller->rt) { + spi->controller->rt = true; + spi_set_thread_rt(spi->controller); + } + + trace_spi_setup(spi, status); + + dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n", + spi->mode & SPI_MODE_X_MASK, + (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", + (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", + (spi->mode & SPI_3WIRE) ? "3wire, " : "", + (spi->mode & SPI_LOOP) ? "loopback, " : "", + spi->bits_per_word, spi->max_speed_hz, + status); + + return status; +} +EXPORT_SYMBOL_GPL(spi_setup); + +static int _spi_xfer_word_delay_update(struct spi_transfer *xfer, + struct spi_device *spi) +{ + int delay1, delay2; + + delay1 = spi_delay_to_ns(&xfer->word_delay, xfer); + if (delay1 < 0) + return delay1; + + delay2 = spi_delay_to_ns(&spi->word_delay, xfer); + if (delay2 < 0) + return delay2; + + if (delay1 < delay2) + memcpy(&xfer->word_delay, &spi->word_delay, + sizeof(xfer->word_delay)); + + return 0; +} + +static int __spi_validate(struct spi_device *spi, struct spi_message *message) +{ + struct spi_controller *ctlr = spi->controller; + struct spi_transfer *xfer; + int w_size; + + if (list_empty(&message->transfers)) + return -EINVAL; + + /* + * If an SPI controller does not support toggling the CS line on each + * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO + * for the CS line, we can emulate the CS-per-word hardware function by + * splitting transfers into one-word transfers and ensuring that + * cs_change is set for each transfer. + */ + if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || + spi_get_csgpiod(spi, 0))) { + size_t maxsize; + int ret; + + maxsize = (spi->bits_per_word + 7) / 8; + + /* spi_split_transfers_maxsize() requires message->spi */ + message->spi = spi; + + ret = spi_split_transfers_maxsize(ctlr, message, maxsize, + GFP_KERNEL); + if (ret) + return ret; + + list_for_each_entry(xfer, &message->transfers, transfer_list) { + /* Don't change cs_change on the last entry in the list */ + if (list_is_last(&xfer->transfer_list, &message->transfers)) + break; + xfer->cs_change = 1; + } + } + + /* + * Half-duplex links include original MicroWire, and ones with + * only one data pin like SPI_3WIRE (switches direction) or where + * either MOSI or MISO is missing. They can also be caused by + * software limitations. + */ + if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) || + (spi->mode & SPI_3WIRE)) { + unsigned flags = ctlr->flags; + + list_for_each_entry(xfer, &message->transfers, transfer_list) { + if (xfer->rx_buf && xfer->tx_buf) + return -EINVAL; + if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf) + return -EINVAL; + if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf) + return -EINVAL; + } + } + + /* + * Set transfer bits_per_word and max speed as spi device default if + * it is not set for this transfer. + * Set transfer tx_nbits and rx_nbits as single transfer default + * (SPI_NBITS_SINGLE) if it is not set for this transfer. + * Ensure transfer word_delay is at least as long as that required by + * device itself. + */ + message->frame_length = 0; + list_for_each_entry(xfer, &message->transfers, transfer_list) { + xfer->effective_speed_hz = 0; + message->frame_length += xfer->len; + if (!xfer->bits_per_word) + xfer->bits_per_word = spi->bits_per_word; + + if (!xfer->speed_hz) + xfer->speed_hz = spi->max_speed_hz; + + if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz) + xfer->speed_hz = ctlr->max_speed_hz; + + if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word)) + return -EINVAL; + + /* + * SPI transfer length should be multiple of SPI word size + * where SPI word size should be power-of-two multiple. + */ + if (xfer->bits_per_word <= 8) + w_size = 1; + else if (xfer->bits_per_word <= 16) + w_size = 2; + else + w_size = 4; + + /* No partial transfers accepted */ + if (xfer->len % w_size) + return -EINVAL; + + if (xfer->speed_hz && ctlr->min_speed_hz && + xfer->speed_hz < ctlr->min_speed_hz) + return -EINVAL; + + if (xfer->tx_buf && !xfer->tx_nbits) + xfer->tx_nbits = SPI_NBITS_SINGLE; + if (xfer->rx_buf && !xfer->rx_nbits) + xfer->rx_nbits = SPI_NBITS_SINGLE; + /* + * Check transfer tx/rx_nbits: + * 1. check the value matches one of single, dual and quad + * 2. check tx/rx_nbits match the mode in spi_device + */ + if (xfer->tx_buf) { + if (spi->mode & SPI_NO_TX) + return -EINVAL; + if (xfer->tx_nbits != SPI_NBITS_SINGLE && + xfer->tx_nbits != SPI_NBITS_DUAL && + xfer->tx_nbits != SPI_NBITS_QUAD) + return -EINVAL; + if ((xfer->tx_nbits == SPI_NBITS_DUAL) && + !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) + return -EINVAL; + if ((xfer->tx_nbits == SPI_NBITS_QUAD) && + !(spi->mode & SPI_TX_QUAD)) + return -EINVAL; + } + /* Check transfer rx_nbits */ + if (xfer->rx_buf) { + if (spi->mode & SPI_NO_RX) + return -EINVAL; + if (xfer->rx_nbits != SPI_NBITS_SINGLE && + xfer->rx_nbits != SPI_NBITS_DUAL && + xfer->rx_nbits != SPI_NBITS_QUAD) + return -EINVAL; + if ((xfer->rx_nbits == SPI_NBITS_DUAL) && + !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) + return -EINVAL; + if ((xfer->rx_nbits == SPI_NBITS_QUAD) && + !(spi->mode & SPI_RX_QUAD)) + return -EINVAL; + } + + if (_spi_xfer_word_delay_update(xfer, spi)) + return -EINVAL; + } + + message->status = -EINPROGRESS; + + return 0; +} + +static int __spi_async(struct spi_device *spi, struct spi_message *message) +{ + struct spi_controller *ctlr = spi->controller; + struct spi_transfer *xfer; + + /* + * Some controllers do not support doing regular SPI transfers. Return + * ENOTSUPP when this is the case. + */ + if (!ctlr->transfer) + return -ENOTSUPP; + + message->spi = spi; + + SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_async); + SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_async); + + trace_spi_message_submit(message); + + if (!ctlr->ptp_sts_supported) { + list_for_each_entry(xfer, &message->transfers, transfer_list) { + xfer->ptp_sts_word_pre = 0; + ptp_read_system_prets(xfer->ptp_sts); + } + } + + return ctlr->transfer(spi, message); +} + +/** + * spi_async - asynchronous SPI transfer + * @spi: device with which data will be exchanged + * @message: describes the data transfers, including completion callback + * Context: any (irqs may be blocked, etc) + * + * This call may be used in_irq and other contexts which can't sleep, + * as well as from task contexts which can sleep. + * + * The completion callback is invoked in a context which can't sleep. + * Before that invocation, the value of message->status is undefined. + * When the callback is issued, message->status holds either zero (to + * indicate complete success) or a negative error code. After that + * callback returns, the driver which issued the transfer request may + * deallocate the associated memory; it's no longer in use by any SPI + * core or controller driver code. + * + * Note that although all messages to a spi_device are handled in + * FIFO order, messages may go to different devices in other orders. + * Some device might be higher priority, or have various "hard" access + * time requirements, for example. + * + * On detection of any fault during the transfer, processing of + * the entire message is aborted, and the device is deselected. + * Until returning from the associated message completion callback, + * no other spi_message queued to that device will be processed. + * (This rule applies equally to all the synchronous transfer calls, + * which are wrappers around this core asynchronous primitive.) + * + * Return: zero on success, else a negative error code. + */ +int spi_async(struct spi_device *spi, struct spi_message *message) +{ + struct spi_controller *ctlr = spi->controller; + int ret; + unsigned long flags; + + ret = __spi_validate(spi, message); + if (ret != 0) + return ret; + + spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); + + if (ctlr->bus_lock_flag) + ret = -EBUSY; + else + ret = __spi_async(spi, message); + + spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); + + return ret; +} +EXPORT_SYMBOL_GPL(spi_async); + +/** + * spi_async_locked - version of spi_async with exclusive bus usage + * @spi: device with which data will be exchanged + * @message: describes the data transfers, including completion callback + * Context: any (irqs may be blocked, etc) + * + * This call may be used in_irq and other contexts which can't sleep, + * as well as from task contexts which can sleep. + * + * The completion callback is invoked in a context which can't sleep. + * Before that invocation, the value of message->status is undefined. + * When the callback is issued, message->status holds either zero (to + * indicate complete success) or a negative error code. After that + * callback returns, the driver which issued the transfer request may + * deallocate the associated memory; it's no longer in use by any SPI + * core or controller driver code. + * + * Note that although all messages to a spi_device are handled in + * FIFO order, messages may go to different devices in other orders. + * Some device might be higher priority, or have various "hard" access + * time requirements, for example. + * + * On detection of any fault during the transfer, processing of + * the entire message is aborted, and the device is deselected. + * Until returning from the associated message completion callback, + * no other spi_message queued to that device will be processed. + * (This rule applies equally to all the synchronous transfer calls, + * which are wrappers around this core asynchronous primitive.) + * + * Return: zero on success, else a negative error code. + */ +static int spi_async_locked(struct spi_device *spi, struct spi_message *message) +{ + struct spi_controller *ctlr = spi->controller; + int ret; + unsigned long flags; + + ret = __spi_validate(spi, message); + if (ret != 0) + return ret; + + spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); + + ret = __spi_async(spi, message); + + spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); + + return ret; + +} + +static void __spi_transfer_message_noqueue(struct spi_controller *ctlr, struct spi_message *msg) +{ + bool was_busy; + int ret; + + mutex_lock(&ctlr->io_mutex); + + was_busy = ctlr->busy; + + ctlr->cur_msg = msg; + ret = __spi_pump_transfer_message(ctlr, msg, was_busy); + if (ret) + dev_err(&ctlr->dev, "noqueue transfer failed\n"); + ctlr->cur_msg = NULL; + ctlr->fallback = false; + + if (!was_busy) { + kfree(ctlr->dummy_rx); + ctlr->dummy_rx = NULL; + kfree(ctlr->dummy_tx); + ctlr->dummy_tx = NULL; + if (ctlr->unprepare_transfer_hardware && + ctlr->unprepare_transfer_hardware(ctlr)) + dev_err(&ctlr->dev, + "failed to unprepare transfer hardware\n"); + spi_idle_runtime_pm(ctlr); + } + + mutex_unlock(&ctlr->io_mutex); +} + +/*-------------------------------------------------------------------------*/ + +/* + * Utility methods for SPI protocol drivers, layered on + * top of the core. Some other utility methods are defined as + * inline functions. + */ + +static void spi_complete(void *arg) +{ + complete(arg); +} + +static int __spi_sync(struct spi_device *spi, struct spi_message *message) +{ + DECLARE_COMPLETION_ONSTACK(done); + int status; + struct spi_controller *ctlr = spi->controller; + + if (__spi_check_suspended(ctlr)) { + dev_warn_once(&spi->dev, "Attempted to sync while suspend\n"); + return -ESHUTDOWN; + } + + status = __spi_validate(spi, message); + if (status != 0) + return status; + + message->spi = spi; + + SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync); + SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync); + + /* + * Checking queue_empty here only guarantees async/sync message + * ordering when coming from the same context. It does not need to + * guard against reentrancy from a different context. The io_mutex + * will catch those cases. + */ + if (READ_ONCE(ctlr->queue_empty) && !ctlr->must_async) { + message->actual_length = 0; + message->status = -EINPROGRESS; + + trace_spi_message_submit(message); + + SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync_immediate); + SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync_immediate); + + __spi_transfer_message_noqueue(ctlr, message); + + return message->status; + } + + /* + * There are messages in the async queue that could have originated + * from the same context, so we need to preserve ordering. + * Therefor we send the message to the async queue and wait until they + * are completed. + */ + message->complete = spi_complete; + message->context = &done; + status = spi_async_locked(spi, message); + if (status == 0) { + wait_for_completion(&done); + status = message->status; + } + message->context = NULL; + + return status; +} + +/** + * spi_sync - blocking/synchronous SPI data transfers + * @spi: device with which data will be exchanged + * @message: describes the data transfers + * Context: can sleep + * + * This call may only be used from a context that may sleep. The sleep + * is non-interruptible, and has no timeout. Low-overhead controller + * drivers may DMA directly into and out of the message buffers. + * + * Note that the SPI device's chip select is active during the message, + * and then is normally disabled between messages. Drivers for some + * frequently-used devices may want to minimize costs of selecting a chip, + * by leaving it selected in anticipation that the next message will go + * to the same chip. (That may increase power usage.) + * + * Also, the caller is guaranteeing that the memory associated with the + * message will not be freed before this call returns. + * + * Return: zero on success, else a negative error code. + */ +int spi_sync(struct spi_device *spi, struct spi_message *message) +{ + int ret; + + mutex_lock(&spi->controller->bus_lock_mutex); + ret = __spi_sync(spi, message); + mutex_unlock(&spi->controller->bus_lock_mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(spi_sync); + +/** + * spi_sync_locked - version of spi_sync with exclusive bus usage + * @spi: device with which data will be exchanged + * @message: describes the data transfers + * Context: can sleep + * + * This call may only be used from a context that may sleep. The sleep + * is non-interruptible, and has no timeout. Low-overhead controller + * drivers may DMA directly into and out of the message buffers. + * + * This call should be used by drivers that require exclusive access to the + * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must + * be released by a spi_bus_unlock call when the exclusive access is over. + * + * Return: zero on success, else a negative error code. + */ +int spi_sync_locked(struct spi_device *spi, struct spi_message *message) +{ + return __spi_sync(spi, message); +} +EXPORT_SYMBOL_GPL(spi_sync_locked); + +/** + * spi_bus_lock - obtain a lock for exclusive SPI bus usage + * @ctlr: SPI bus master that should be locked for exclusive bus access + * Context: can sleep + * + * This call may only be used from a context that may sleep. The sleep + * is non-interruptible, and has no timeout. + * + * This call should be used by drivers that require exclusive access to the + * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the + * exclusive access is over. Data transfer must be done by spi_sync_locked + * and spi_async_locked calls when the SPI bus lock is held. + * + * Return: always zero. + */ +int spi_bus_lock(struct spi_controller *ctlr) +{ + unsigned long flags; + + mutex_lock(&ctlr->bus_lock_mutex); + + spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); + ctlr->bus_lock_flag = 1; + spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); + + /* Mutex remains locked until spi_bus_unlock() is called */ + + return 0; +} +EXPORT_SYMBOL_GPL(spi_bus_lock); + +/** + * spi_bus_unlock - release the lock for exclusive SPI bus usage + * @ctlr: SPI bus master that was locked for exclusive bus access + * Context: can sleep + * + * This call may only be used from a context that may sleep. The sleep + * is non-interruptible, and has no timeout. + * + * This call releases an SPI bus lock previously obtained by an spi_bus_lock + * call. + * + * Return: always zero. + */ +int spi_bus_unlock(struct spi_controller *ctlr) +{ + ctlr->bus_lock_flag = 0; + + mutex_unlock(&ctlr->bus_lock_mutex); + + return 0; +} +EXPORT_SYMBOL_GPL(spi_bus_unlock); + +/* Portable code must never pass more than 32 bytes */ +#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES) + +static u8 *buf; + +/** + * spi_write_then_read - SPI synchronous write followed by read + * @spi: device with which data will be exchanged + * @txbuf: data to be written (need not be dma-safe) + * @n_tx: size of txbuf, in bytes + * @rxbuf: buffer into which data will be read (need not be dma-safe) + * @n_rx: size of rxbuf, in bytes + * Context: can sleep + * + * This performs a half duplex MicroWire style transaction with the + * device, sending txbuf and then reading rxbuf. The return value + * is zero for success, else a negative errno status code. + * This call may only be used from a context that may sleep. + * + * Parameters to this routine are always copied using a small buffer. + * Performance-sensitive or bulk transfer code should instead use + * spi_{async,sync}() calls with dma-safe buffers. + * + * Return: zero on success, else a negative error code. + */ +int spi_write_then_read(struct spi_device *spi, + const void *txbuf, unsigned n_tx, + void *rxbuf, unsigned n_rx) +{ + static DEFINE_MUTEX(lock); + + int status; + struct spi_message message; + struct spi_transfer x[2]; + u8 *local_buf; + + /* + * Use preallocated DMA-safe buffer if we can. We can't avoid + * copying here, (as a pure convenience thing), but we can + * keep heap costs out of the hot path unless someone else is + * using the pre-allocated buffer or the transfer is too large. + */ + if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { + local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), + GFP_KERNEL | GFP_DMA); + if (!local_buf) + return -ENOMEM; + } else { + local_buf = buf; + } + + spi_message_init(&message); + memset(x, 0, sizeof(x)); + if (n_tx) { + x[0].len = n_tx; + spi_message_add_tail(&x[0], &message); + } + if (n_rx) { + x[1].len = n_rx; + spi_message_add_tail(&x[1], &message); + } + + memcpy(local_buf, txbuf, n_tx); + x[0].tx_buf = local_buf; + x[1].rx_buf = local_buf + n_tx; + + /* Do the i/o */ + status = spi_sync(spi, &message); + if (status == 0) + memcpy(rxbuf, x[1].rx_buf, n_rx); + + if (x[0].tx_buf == buf) + mutex_unlock(&lock); + else + kfree(local_buf); + + return status; +} +EXPORT_SYMBOL_GPL(spi_write_then_read); + +/*-------------------------------------------------------------------------*/ + +#if IS_ENABLED(CONFIG_OF_DYNAMIC) +/* Must call put_device() when done with returned spi_device device */ +static struct spi_device *of_find_spi_device_by_node(struct device_node *node) +{ + struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node); + + return dev ? to_spi_device(dev) : NULL; +} + +/* The spi controllers are not using spi_bus, so we find it with another way */ +static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node) +{ + struct device *dev; + + dev = class_find_device_by_of_node(&spi_master_class, node); + if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE)) + dev = class_find_device_by_of_node(&spi_slave_class, node); + if (!dev) + return NULL; + + /* Reference got in class_find_device */ + return container_of(dev, struct spi_controller, dev); +} + +static int of_spi_notify(struct notifier_block *nb, unsigned long action, + void *arg) +{ + struct of_reconfig_data *rd = arg; + struct spi_controller *ctlr; + struct spi_device *spi; + + switch (of_reconfig_get_state_change(action, arg)) { + case OF_RECONFIG_CHANGE_ADD: + ctlr = of_find_spi_controller_by_node(rd->dn->parent); + if (ctlr == NULL) + return NOTIFY_OK; /* Not for us */ + + if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { + put_device(&ctlr->dev); + return NOTIFY_OK; + } + + /* + * Clear the flag before adding the device so that fw_devlink + * doesn't skip adding consumers to this device. + */ + rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE; + spi = of_register_spi_device(ctlr, rd->dn); + put_device(&ctlr->dev); + + if (IS_ERR(spi)) { + pr_err("%s: failed to create for '%pOF'\n", + __func__, rd->dn); + of_node_clear_flag(rd->dn, OF_POPULATED); + return notifier_from_errno(PTR_ERR(spi)); + } + break; + + case OF_RECONFIG_CHANGE_REMOVE: + /* Already depopulated? */ + if (!of_node_check_flag(rd->dn, OF_POPULATED)) + return NOTIFY_OK; + + /* Find our device by node */ + spi = of_find_spi_device_by_node(rd->dn); + if (spi == NULL) + return NOTIFY_OK; /* No? not meant for us */ + + /* Unregister takes one ref away */ + spi_unregister_device(spi); + + /* And put the reference of the find */ + put_device(&spi->dev); + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block spi_of_notifier = { + .notifier_call = of_spi_notify, +}; +#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ +extern struct notifier_block spi_of_notifier; +#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ + +#if IS_ENABLED(CONFIG_ACPI) +static int spi_acpi_controller_match(struct device *dev, const void *data) +{ + return ACPI_COMPANION(dev->parent) == data; +} + +static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev) +{ + struct device *dev; + + dev = class_find_device(&spi_master_class, NULL, adev, + spi_acpi_controller_match); + if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE)) + dev = class_find_device(&spi_slave_class, NULL, adev, + spi_acpi_controller_match); + if (!dev) + return NULL; + + return container_of(dev, struct spi_controller, dev); +} + +static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev) +{ + struct device *dev; + + dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev); + return to_spi_device(dev); +} + +static int acpi_spi_notify(struct notifier_block *nb, unsigned long value, + void *arg) +{ + struct acpi_device *adev = arg; + struct spi_controller *ctlr; + struct spi_device *spi; + + switch (value) { + case ACPI_RECONFIG_DEVICE_ADD: + ctlr = acpi_spi_find_controller_by_adev(acpi_dev_parent(adev)); + if (!ctlr) + break; + + acpi_register_spi_device(ctlr, adev); + put_device(&ctlr->dev); + break; + case ACPI_RECONFIG_DEVICE_REMOVE: + if (!acpi_device_enumerated(adev)) + break; + + spi = acpi_spi_find_device_by_adev(adev); + if (!spi) + break; + + spi_unregister_device(spi); + put_device(&spi->dev); + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block spi_acpi_notifier = { + .notifier_call = acpi_spi_notify, +}; +#else +extern struct notifier_block spi_acpi_notifier; +#endif + +static int __init spi_init(void) +{ + int status; + + buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); + if (!buf) { + status = -ENOMEM; + goto err0; + } + + status = bus_register(&spi_bus_type); + if (status < 0) + goto err1; + + status = class_register(&spi_master_class); + if (status < 0) + goto err2; + + if (IS_ENABLED(CONFIG_SPI_SLAVE)) { + status = class_register(&spi_slave_class); + if (status < 0) + goto err3; + } + + if (IS_ENABLED(CONFIG_OF_DYNAMIC)) + WARN_ON(of_reconfig_notifier_register(&spi_of_notifier)); + if (IS_ENABLED(CONFIG_ACPI)) + WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier)); + + return 0; + +err3: + class_unregister(&spi_master_class); +err2: + bus_unregister(&spi_bus_type); +err1: + kfree(buf); + buf = NULL; +err0: + return status; +} + +/* + * A board_info is normally registered in arch_initcall(), + * but even essential drivers wait till later. + * + * REVISIT only boardinfo really needs static linking. The rest (device and + * driver registration) _could_ be dynamically linked (modular) ... Costs + * include needing to have boardinfo data structures be much more public. + */ +postcore_initcall(spi_init); |