diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/spi/spi.c | 3622 |
1 files changed, 3622 insertions, 0 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c new file mode 100644 index 000000000..3bcd6f178 --- /dev/null +++ b/drivers/spi/spi.c @@ -0,0 +1,3622 @@ +/* + * SPI init/core code + * + * Copyright (C) 2005 David Brownell + * Copyright (C) 2008 Secret Lab Technologies Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#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/of_gpio.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> + +#define CREATE_TRACE_POINTS +#include <trace/events/spi.h> + +#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 controllers may cleanup for released devices */ + if (spi->controller->cleanup) + spi->controller->cleanup(spi); + + spi_controller_put(spi->controller); + 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); + +#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->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->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, format_string) \ +static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \ + char *buf) \ +{ \ + unsigned long flags; \ + ssize_t len; \ + spin_lock_irqsave(&stat->lock, flags); \ + len = sprintf(buf, format_string, stat->field); \ + spin_unlock_irqrestore(&stat->lock, flags); \ + return len; \ +} \ +SPI_STATISTICS_ATTRS(name, file) + +#define SPI_STATISTICS_SHOW(field, format_string) \ + SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \ + field, format_string) + +SPI_STATISTICS_SHOW(messages, "%lu"); +SPI_STATISTICS_SHOW(transfers, "%lu"); +SPI_STATISTICS_SHOW(errors, "%lu"); +SPI_STATISTICS_SHOW(timedout, "%lu"); + +SPI_STATISTICS_SHOW(spi_sync, "%lu"); +SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu"); +SPI_STATISTICS_SHOW(spi_async, "%lu"); + +SPI_STATISTICS_SHOW(bytes, "%llu"); +SPI_STATISTICS_SHOW(bytes_rx, "%llu"); +SPI_STATISTICS_SHOW(bytes_tx, "%llu"); + +#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \ + SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \ + "transfer_bytes_histo_" number, \ + transfer_bytes_histo[index], "%lu") +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, "%lu"); + +static struct attribute *spi_dev_attrs[] = { + &dev_attr_modalias.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, +}; + +void spi_statistics_add_transfer_stats(struct spi_statistics *stats, + struct spi_transfer *xfer, + struct spi_controller *ctlr) +{ + unsigned long flags; + int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1; + + if (l2len < 0) + l2len = 0; + + spin_lock_irqsave(&stats->lock, flags); + + stats->transfers++; + stats->transfer_bytes_histo[l2len]++; + + stats->bytes += xfer->len; + if ((xfer->tx_buf) && + (xfer->tx_buf != ctlr->dummy_tx)) + stats->bytes_tx += xfer->len; + if ((xfer->rx_buf) && + (xfer->rx_buf != ctlr->dummy_rx)) + stats->bytes_rx += xfer->len; + + spin_unlock_irqrestore(&stats->lock, flags); +} +EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats); + +/* 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 struct spi_device *sdev) +{ + while (id->name[0]) { + if (!strcmp(sdev->modalias, 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); +} +EXPORT_SYMBOL_GPL(spi_get_device_id); + +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); + + /* 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); + + 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); +} + +struct bus_type spi_bus_type = { + .name = "spi", + .dev_groups = spi_dev_groups, + .match = spi_match_device, + .uevent = spi_uevent, +}; +EXPORT_SYMBOL_GPL(spi_bus_type); + + +static int spi_drv_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 int spi_drv_remove(struct device *dev) +{ + const struct spi_driver *sdrv = to_spi_driver(dev->driver); + int ret = 0; + + if (sdrv->remove) + ret = sdrv->remove(to_spi_device(dev)); + dev_pm_domain_detach(dev, true); + + return ret; +} + +static void spi_drv_shutdown(struct device *dev) +{ + const struct spi_driver *sdrv = to_spi_driver(dev->driver); + + sdrv->shutdown(to_spi_device(dev)); +} + +/** + * __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; + sdrv->driver.probe = spi_drv_probe; + sdrv->driver.remove = spi_drv_remove; + if (sdrv->shutdown) + sdrv->driver.shutdown = spi_drv_shutdown; + 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 opertion 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); + +/* + * Prevents addition of devices with same chip select and + * addition of devices below an unregistering controller. + */ +static DEFINE_MUTEX(spi_add_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->master = spi->controller = ctlr; + spi->dev.parent = &ctlr->dev; + spi->dev.bus = &spi_bus_type; + spi->dev.release = spidev_release; + spi->cs_gpio = -ENOENT; + + spin_lock_init(&spi->statistics.lock); + + 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->chip_select); +} + +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->chip_select == new_spi->chip_select) + return -EBUSY; + return 0; +} + +/** + * 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->chip_select >= ctlr->num_chipselect) { + dev_err(dev, "cs%d >= max %d\n", spi->chip_select, + ctlr->num_chipselect); + return -EINVAL; + } + + /* Set the bus ID string */ + spi_dev_set_name(spi); + + /* We need to make sure there's no other device with this + * chipselect **BEFORE** we call setup(), else we'll trash + * its configuration. Lock against concurrent add() calls. + */ + mutex_lock(&spi_add_lock); + + 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->chip_select); + goto done; + } + + /* Controller may unregister concurrently */ + if (IS_ENABLED(CONFIG_SPI_DYNAMIC) && + !device_is_registered(&ctlr->dev)) { + status = -ENODEV; + goto done; + } + + if (ctlr->cs_gpios) + spi->cs_gpio = ctlr->cs_gpios[spi->chip_select]; + + /* 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); + goto done; + } + + /* 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); + else + dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); + +done: + mutex_unlock(&spi_add_lock); + return status; +} +EXPORT_SYMBOL_GPL(spi_add_device); + +/** + * 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)); + + proxy->chip_select = chip->chip_select; + proxy->max_speed_hz = chip->max_speed_hz; + proxy->mode = chip->mode; + proxy->irq = chip->irq; + strlcpy(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->properties) { + status = device_add_properties(&proxy->dev, chip->properties); + if (status) { + dev_err(&ctlr->dev, + "failed to add properties to '%s': %d\n", + chip->modalias, status); + goto err_dev_put; + } + } + + status = spi_add_device(proxy); + if (status < 0) + goto err_remove_props; + + return proxy; + +err_remove_props: + if (chip->properties) + device_remove_properties(&proxy->dev); +err_dev_put: + 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_unregister(&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. + * Device properties are deep-copied though. + * + * 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)); + if (info->properties) { + bi->board_info.properties = + property_entries_dup(info->properties); + if (IS_ERR(bi->board_info.properties)) + return PTR_ERR(bi->board_info.properties); + } + + 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; +} + +/*-------------------------------------------------------------------------*/ + +static void spi_set_cs(struct spi_device *spi, bool enable) +{ + if (spi->mode & SPI_CS_HIGH) + enable = !enable; + + if (gpio_is_valid(spi->cs_gpio)) { + gpio_set_value(spi->cs_gpio, !enable); + /* 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); + } +} + +#ifdef CONFIG_HAS_DMA +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) +{ + 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_sg(dev, sgt->sgl, sgt->nents, dir); + if (!ret) + ret = -ENOMEM; + if (ret < 0) { + sg_free_table(sgt); + return ret; + } + + sgt->nents = ret; + + return 0; +} + +void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev, + struct sg_table *sgt, enum dma_data_direction dir) +{ + if (sgt->orig_nents) { + dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir); + sg_free_table(sgt); + } +} + +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 + tx_dev = ctlr->dev.parent; + + if (ctlr->dma_rx) + rx_dev = ctlr->dma_rx->device->dev; + else + rx_dev = ctlr->dev.parent; + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + if (!ctlr->can_dma(ctlr, msg->spi, xfer)) + continue; + + if (xfer->tx_buf != NULL) { + ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg, + (void *)xfer->tx_buf, xfer->len, + DMA_TO_DEVICE); + if (ret != 0) + return ret; + } + + if (xfer->rx_buf != NULL) { + ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg, + xfer->rx_buf, xfer->len, + DMA_FROM_DEVICE); + if (ret != 0) { + spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, + DMA_TO_DEVICE); + return ret; + } + } + } + + ctlr->cur_msg_mapped = true; + + return 0; +} + +static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg) +{ + struct spi_transfer *xfer; + struct device *tx_dev, *rx_dev; + + if (!ctlr->cur_msg_mapped || !ctlr->can_dma) + return 0; + + if (ctlr->dma_tx) + tx_dev = ctlr->dma_tx->device->dev; + else + tx_dev = ctlr->dev.parent; + + if (ctlr->dma_rx) + rx_dev = ctlr->dma_rx->device->dev; + else + rx_dev = ctlr->dev.parent; + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + if (!ctlr->can_dma(ctlr, msg->spi, xfer)) + continue; + + spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); + spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); + } + + return 0; +} +#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; +} +#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)) { + 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); + if (!tmp) + return -ENOMEM; + ctlr->dummy_tx = tmp; + memset(tmp, 0, max_tx); + } + + 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); +} + +/* + * 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; + unsigned long long ms = 1; + struct spi_statistics *statm = &ctlr->statistics; + struct spi_statistics *stats = &msg->spi->statistics; + + spi_set_cs(msg->spi, true); + + 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 (xfer->tx_buf || xfer->rx_buf) { + reinit_completion(&ctlr->xfer_completion); + + ret = ctlr->transfer_one(ctlr, msg->spi, xfer); + if (ret < 0) { + 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 = 0; + ms = 8LL * 1000LL * xfer->len; + do_div(ms, xfer->speed_hz); + ms += ms + 200; /* some tolerance */ + + 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"); + msg->status = -ETIMEDOUT; + } + } else { + if (xfer->len) + dev_err(&msg->spi->dev, + "Bufferless transfer has length %u\n", + xfer->len); + } + + trace_spi_transfer_stop(msg, xfer); + + if (msg->status != -EINPROGRESS) + goto out; + + if (xfer->delay_usecs) { + u16 us = xfer->delay_usecs; + + if (us <= 10) + udelay(us); + else + usleep_range(us, us + DIV_ROUND_UP(us, 10)); + } + + if (xfer->cs_change) { + if (list_is_last(&xfer->transfer_list, + &msg->transfers)) { + keep_cs = true; + } else { + spi_set_cs(msg->spi, false); + udelay(10); + spi_set_cs(msg->spi, true); + } + } + + msg->actual_length += xfer->len; + } + +out: + if (ret != 0 || !keep_cs) + spi_set_cs(msg->spi, 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); + +/** + * __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) +{ + unsigned long flags; + bool was_busy = false; + int ret; + + /* Lock queue */ + spin_lock_irqsave(&ctlr->queue_lock, flags); + + /* Make sure we are not already running a message */ + if (ctlr->cur_msg) { + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + return; + } + + /* If another context is idling the device then defer */ + if (ctlr->idling) { + kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages); + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + return; + } + + /* Check if the queue is idle */ + if (list_empty(&ctlr->queue) || !ctlr->running) { + if (!ctlr->busy) { + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + return; + } + + /* Only do teardown in the thread */ + if (!in_kthread) { + kthread_queue_work(&ctlr->kworker, + &ctlr->pump_messages); + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + return; + } + + ctlr->busy = false; + ctlr->idling = true; + 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"); + if (ctlr->auto_runtime_pm) { + pm_runtime_mark_last_busy(ctlr->dev.parent); + pm_runtime_put_autosuspend(ctlr->dev.parent); + } + trace_spi_controller_idle(ctlr); + + spin_lock_irqsave(&ctlr->queue_lock, flags); + ctlr->idling = false; + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + return; + } + + /* Extract head of queue */ + ctlr->cur_msg = + list_first_entry(&ctlr->queue, struct spi_message, queue); + + list_del_init(&ctlr->cur_msg->queue); + if (ctlr->busy) + was_busy = true; + else + ctlr->busy = true; + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + + mutex_lock(&ctlr->io_mutex); + + 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); + mutex_unlock(&ctlr->io_mutex); + return; + } + } + + 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\n"); + + if (ctlr->auto_runtime_pm) + pm_runtime_put(ctlr->dev.parent); + mutex_unlock(&ctlr->io_mutex); + return; + } + } + + trace_spi_message_start(ctlr->cur_msg); + + if (ctlr->prepare_message) { + ret = ctlr->prepare_message(ctlr, ctlr->cur_msg); + if (ret) { + dev_err(&ctlr->dev, "failed to prepare message: %d\n", + ret); + ctlr->cur_msg->status = ret; + spi_finalize_current_message(ctlr); + goto out; + } + ctlr->cur_msg_prepared = true; + } + + ret = spi_map_msg(ctlr, ctlr->cur_msg); + if (ret) { + ctlr->cur_msg->status = ret; + spi_finalize_current_message(ctlr); + goto out; + } + + ret = ctlr->transfer_one_message(ctlr, ctlr->cur_msg); + if (ret) { + dev_err(&ctlr->dev, + "failed to transfer one message from queue\n"); + goto out; + } + +out: + mutex_unlock(&ctlr->io_mutex); + + /* Prod the scheduler in case transfer_one() was busy waiting */ + if (!ret) + cond_resched(); +} + +/** + * 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); +} + +static int spi_init_queue(struct spi_controller *ctlr) +{ + struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; + + ctlr->running = false; + ctlr->busy = false; + + kthread_init_worker(&ctlr->kworker); + ctlr->kworker_task = kthread_run(kthread_worker_fn, &ctlr->kworker, + "%s", dev_name(&ctlr->dev)); + if (IS_ERR(ctlr->kworker_task)) { + dev_err(&ctlr->dev, "failed to create message pump task\n"); + return PTR_ERR(ctlr->kworker_task); + } + 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) { + dev_info(&ctlr->dev, + "will run message pump with realtime priority\n"); + sched_setscheduler(ctlr->kworker_task, SCHED_FIFO, ¶m); + } + + 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_message *mesg; + unsigned long flags; + int ret; + + spin_lock_irqsave(&ctlr->queue_lock, flags); + mesg = ctlr->cur_msg; + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + + spi_unmap_msg(ctlr, mesg); + + /* In the prepare_messages callback the spi bus has the opportunity to + * split a transfer to smaller chunks. + * Release splited transfers here since spi_map_msg is done on the + * splited transfers. + */ + spi_res_release(ctlr, mesg); + + if (ctlr->cur_msg_prepared && ctlr->unprepare_message) { + ret = ctlr->unprepare_message(ctlr, mesg); + if (ret) { + dev_err(&ctlr->dev, "failed to unprepare message: %d\n", + ret); + } + } + + spin_lock_irqsave(&ctlr->queue_lock, flags); + ctlr->cur_msg = NULL; + ctlr->cur_msg_prepared = false; + kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages); + spin_unlock_irqrestore(&ctlr->queue_lock, flags); + + 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_flush_worker(&ctlr->kworker); + kthread_stop(ctlr->kworker_task); + + 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); + 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-cs-high")) + spi->mode |= SPI_CS_HIGH; + 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; + + /* Device DUAL/QUAD mode */ + if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { + switch (value) { + case 1: + break; + case 2: + spi->mode |= SPI_TX_DUAL; + break; + case 4: + spi->mode |= SPI_TX_QUAD; + 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 1: + break; + case 2: + spi->mode |= SPI_RX_DUAL; + break; + case 4: + spi->mode |= SPI_RX_QUAD; + break; + default: + dev_warn(&ctlr->dev, + "spi-rx-bus-width %d not supported\n", + value); + break; + } + } + + if (spi_controller_is_slave(ctlr)) { + if (strcmp(nc->name, "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->chip_select = value; + + /* Device speed */ + rc = of_property_read_u32(nc, "spi-max-frequency", &value); + if (rc) { + dev_err(&ctlr->dev, + "%pOF has no valid 'spi-max-frequency' property (%d)\n", nc, rc); + return rc; + } + 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 + +#ifdef CONFIG_ACPI +static void acpi_spi_parse_apple_properties(struct spi_device *spi) +{ + struct acpi_device *dev = ACPI_COMPANION(&spi->dev); + 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) + spi->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) + spi->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) + spi->mode |= SPI_LSB_FIRST; + + if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj) + && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) + spi->mode |= SPI_CPOL; + + if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj) + && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) + spi->mode |= SPI_CPHA; +} + +static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) +{ + struct spi_device *spi = data; + struct spi_controller *ctlr = spi->controller; + + if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { + struct acpi_resource_spi_serialbus *sb; + + sb = &ares->data.spi_serial_bus; + if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { + /* + * 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; + spi->chip_select = cs; + } else { + spi->chip_select = sb->device_selection; + } + + spi->max_speed_hz = sb->connection_speed; + + if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) + spi->mode |= SPI_CPHA; + if (sb->clock_polarity == ACPI_SPI_START_HIGH) + spi->mode |= SPI_CPOL; + if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) + spi->mode |= SPI_CS_HIGH; + } + } else if (spi->irq < 0) { + struct resource r; + + if (acpi_dev_resource_interrupt(ares, 0, &r)) + spi->irq = r.start; + } + + /* Always tell the ACPI core to skip this resource */ + return 1; +} + +static acpi_status acpi_register_spi_device(struct spi_controller *ctlr, + struct acpi_device *adev) +{ + struct list_head resource_list; + struct spi_device *spi; + int ret; + + if (acpi_bus_get_status(adev) || !adev->status.present || + acpi_device_enumerated(adev)) + return AE_OK; + + spi = spi_alloc_device(ctlr); + if (!spi) { + dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n", + dev_name(&adev->dev)); + return AE_NO_MEMORY; + } + + ACPI_COMPANION_SET(&spi->dev, adev); + spi->irq = -1; + + INIT_LIST_HEAD(&resource_list); + ret = acpi_dev_get_resources(adev, &resource_list, + acpi_spi_add_resource, spi); + acpi_dev_free_resource_list(&resource_list); + + acpi_spi_parse_apple_properties(spi); + + if (ret < 0 || !spi->max_speed_hz) { + spi_dev_put(spi); + 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 spi_controller *ctlr = data; + struct acpi_device *adev; + + if (acpi_bus_get_device(handle, &adev)) + return AE_OK; + + return acpi_register_spi_device(ctlr, adev); +} + +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, handle, 1, + 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 int match_true(struct device *dev, void *data) +{ + return 1; +} + +static ssize_t spi_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_child(&ctlr->dev, NULL, match_true); + return sprintf(buf, "%s\n", + child ? to_spi_device(child)->modalias : NULL); +} + +static ssize_t spi_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_child(&ctlr->dev, NULL, match_true); + 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; + + strlcpy(spi->modalias, name, sizeof(spi->modalias)); + + rc = spi_add_device(spi); + if (rc) { + spi_dev_put(spi); + return rc; + } + } + + return count; +} + +static DEVICE_ATTR(slave, 0644, spi_slave_show, spi_slave_store); + +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(). + * @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; + + if (!dev) + return NULL; + + ctlr = kzalloc(size + sizeof(*ctlr), GFP_KERNEL); + if (!ctlr) + return NULL; + + device_initialize(&ctlr->dev); + 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, &ctlr[1]); + + 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); + +#ifdef CONFIG_OF +static int of_spi_register_master(struct spi_controller *ctlr) +{ + int nb, i, *cs; + struct device_node *np = ctlr->dev.of_node; + + if (!np) + return 0; + + nb = of_gpio_named_count(np, "cs-gpios"); + ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect); + + /* Return error only for an incorrectly formed cs-gpios property */ + if (nb == 0 || nb == -ENOENT) + return 0; + else if (nb < 0) + return nb; + + cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int), + GFP_KERNEL); + ctlr->cs_gpios = cs; + + if (!ctlr->cs_gpios) + return -ENOMEM; + + for (i = 0; i < ctlr->num_chipselect; i++) + cs[i] = -ENOENT; + + for (i = 0; i < nb; i++) + cs[i] = of_get_named_gpio(np, "cs-gpios", i); + + return 0; +} +#else +static int of_spi_register_master(struct spi_controller *ctlr) +{ + return 0; +} +#endif + +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 = -ENODEV; + 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 (!spi_controller_is_slave(ctlr)) { + status = of_spi_register_master(ctlr); + if (status) + return status; + } + + /* even if it's just one always-selected device, there must + * be at least one chipselect + */ + if (ctlr->num_chipselect == 0) + return -EINVAL; + 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; + } + 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); + ctlr->bus_lock_flag = 0; + init_completion(&ctlr->xfer_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); + status = device_add(&ctlr->dev); + if (status < 0) { + /* free bus id */ + mutex_lock(&board_lock); + idr_remove(&spi_master_idr, ctlr->bus_num); + mutex_unlock(&board_lock); + goto done; + } + 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); + /* free bus id */ + mutex_lock(&board_lock); + idr_remove(&spi_master_idr, ctlr->bus_num); + mutex_unlock(&board_lock); + goto done; + } + } + /* add statistics */ + spin_lock_init(&ctlr->statistics.lock); + + 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); +done: + 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(&spi_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); + + /* 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); + + /* 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(&spi_add_lock); +} +EXPORT_SYMBOL_GPL(spi_unregister_controller); + +int spi_controller_suspend(struct spi_controller *ctlr) +{ + int ret; + + /* Basically no-ops for non-queued controllers */ + if (!ctlr->queued) + return 0; + + ret = spi_stop_queue(ctlr); + if (ret) + dev_err(&ctlr->dev, "queue stop failed\n"); + + return ret; +} +EXPORT_SYMBOL_GPL(spi_controller_suspend); + +int spi_controller_resume(struct spi_controller *ctlr) +{ + int ret; + + if (!ctlr->queued) + return 0; + + ret = spi_start_queue(ctlr); + if (ret) + dev_err(&ctlr->dev, "queue restart failed\n"); + + return ret; +} +EXPORT_SYMBOL_GPL(spi_controller_resume); + +static int __spi_controller_match(struct device *dev, const void *data) +{ + struct spi_controller *ctlr; + const u16 *bus_num = data; + + ctlr = container_of(dev, struct spi_controller, dev); + return ctlr->bus_num == *bus_num; +} + +/** + * spi_busnum_to_master - look up master associated with bus_num + * @bus_num: the master's bus number + * Context: can sleep + * + * This call may be used with devices that are registered after + * arch init time. It returns a refcounted pointer to the relevant + * spi_controller (which the caller must release), or NULL if there is + * no such master registered. + * + * Return: the SPI master structure on success, else NULL. + */ +struct spi_controller *spi_busnum_to_master(u16 bus_num) +{ + struct device *dev; + struct spi_controller *ctlr = NULL; + + dev = class_find_device(&spi_master_class, NULL, &bus_num, + __spi_controller_match); + if (dev) + ctlr = container_of(dev, struct spi_controller, dev); + /* reference got in class_find_device */ + return ctlr; +} +EXPORT_SYMBOL_GPL(spi_busnum_to_master); + +/*-------------------------------------------------------------------------*/ + +/* 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. + */ +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; +} +EXPORT_SYMBOL_GPL(spi_res_alloc); + +/** + * spi_res_free - free an spi resource + * @res: pointer to the custom data of a resource + * + */ +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); +} +EXPORT_SYMBOL_GPL(spi_res_free); + +/** + * spi_res_add - add a spi_res to the spi_message + * @message: the spi message + * @res: the spi_resource + */ +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); +} +EXPORT_SYMBOL_GPL(spi_res_add); + +/** + * spi_res_release - release all spi resources for this message + * @ctlr: the @spi_controller + * @message: the @spi_message + */ +void spi_res_release(struct spi_controller *ctlr, struct spi_message *message) +{ + struct spi_res *res; + + while (!list_empty(&message->resources)) { + res = list_last_entry(&message->resources, + struct spi_res, entry); + + if (res->release) + res->release(ctlr, message, res->data); + + list_del(&res->entry); + + kfree(res); + } +} +EXPORT_SYMBOL_GPL(spi_res_release); + +/*-------------------------------------------------------------------------*/ + +/* 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. + */ +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, + insert * sizeof(struct spi_transfer) + + sizeof(struct spi_replaced_transfers) + + 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_usecs for all but the last */ + if (i) { + xfer->cs_change = false; + xfer->delay_usecs = 0; + } + } + + /* set up inserted */ + rxfer->inserted = insert; + + /* and register it with spi_res/spi_message */ + spi_res_add(msg, rxfer); + + return rxfer; +} +EXPORT_SYMBOL_GPL(spi_replace_transfers); + +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; + + /* warn once about this fact that we are splitting a transfer */ + dev_warn_once(&msg->spi->dev, + "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n", + xfer->len, maxsize); + + /* 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->statistics, + transfers_split_maxsize); + SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics, + transfers_split_maxsize); + + return 0; +} + +/** + * spi_split_tranfers_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 + * potentiall 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_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; + + /* check mode to prevent that DUAL and QUAD set at the same time + */ + if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) || + ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) { + dev_err(&spi->dev, + "setup: can not select dual and quad 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_RX_DUAL | SPI_RX_QUAD))) + return -EINVAL; + /* help drivers fail *cleanly* when they need options + * that aren't supported with their current controller + */ + bad_bits = spi->mode & ~spi->controller->mode_bits; + ugly_bits = bad_bits & + (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD); + 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; + + status = __spi_validate_bits_per_word(spi->controller, + spi->bits_per_word); + if (status) + return status; + + if (!spi->max_speed_hz) + spi->max_speed_hz = spi->controller->max_speed_hz; + + if (spi->controller->setup) + status = spi->controller->setup(spi); + + spi_set_cs(spi, false); + + dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", + (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), + (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_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; + + /* 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. + */ + message->frame_length = 0; + list_for_each_entry(xfer, &message->transfers, transfer_list) { + 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 (!xfer->speed_hz) + xfer->speed_hz = ctlr->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 (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 (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; + } + } + + message->status = -EINPROGRESS; + + return 0; +} + +static int __spi_async(struct spi_device *spi, struct spi_message *message) +{ + struct spi_controller *ctlr = spi->controller; + + /* + * 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->statistics, spi_async); + SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async); + + trace_spi_message_submit(message); + + 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. + */ +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; + +} +EXPORT_SYMBOL_GPL(spi_async_locked); + +/*-------------------------------------------------------------------------*/ + +/* 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; + unsigned long flags; + + status = __spi_validate(spi, message); + if (status != 0) + return status; + + message->complete = spi_complete; + message->context = &done; + message->spi = spi; + + SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync); + SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync); + + /* If we're not using the legacy transfer method then we will + * try to transfer in the calling context so special case. + * This code would be less tricky if we could remove the + * support for driver implemented message queues. + */ + if (ctlr->transfer == spi_queued_transfer) { + spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); + + trace_spi_message_submit(message); + + status = __spi_queued_transfer(spi, message, false); + + spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); + } else { + status = spi_async_locked(spi, message); + } + + if (status == 0) { + /* Push out the messages in the calling context if we + * can. + */ + if (ctlr->transfer == spi_queued_transfer) { + SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, + spi_sync_immediate); + SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, + spi_sync_immediate); + __spi_pump_messages(ctlr, false); + } + + 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; + * portable code should never use this for more than 32 bytes. + * 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) +static int __spi_of_device_match(struct device *dev, void *data) +{ + return dev->of_node == data; +} + +/* 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(&spi_bus_type, NULL, node, + __spi_of_device_match); + return dev ? to_spi_device(dev) : NULL; +} + +static int __spi_of_controller_match(struct device *dev, const void *data) +{ + return dev->of_node == data; +} + +/* 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(&spi_master_class, NULL, node, + __spi_of_controller_match); + if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE)) + dev = class_find_device(&spi_slave_class, NULL, node, + __spi_of_controller_match); + 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; + } + + 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 int spi_acpi_device_match(struct device *dev, void *data) +{ + return ACPI_COMPANION(dev) == 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(&spi_bus_type, NULL, adev, spi_acpi_device_match); + + return dev ? to_spi_device(dev) : NULL; +} + +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(adev->parent); + 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; +} + +/* 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); + |