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-rw-r--r--drivers/spi/spi.c4609
1 files changed, 4609 insertions, 0 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
new file mode 100644
index 000000000..19688f333
--- /dev/null
+++ b/drivers/spi/spi.c
@@ -0,0 +1,4609 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// SPI init/core code
+//
+// Copyright (C) 2005 David Brownell
+// Copyright (C) 2008 Secret Lab Technologies Ltd.
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/cache.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/mutex.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/clk/clk-conf.h>
+#include <linux/slab.h>
+#include <linux/mod_devicetable.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi-mem.h>
+#include <linux/gpio/consumer.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_domain.h>
+#include <linux/property.h>
+#include <linux/export.h>
+#include <linux/sched/rt.h>
+#include <uapi/linux/sched/types.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/ioport.h>
+#include <linux/acpi.h>
+#include <linux/highmem.h>
+#include <linux/idr.h>
+#include <linux/platform_data/x86/apple.h>
+#include <linux/ptp_clock_kernel.h>
+#include <linux/percpu.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/spi.h>
+EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start);
+EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop);
+
+#include "internals.h"
+
+static DEFINE_IDR(spi_master_idr);
+
+static void spidev_release(struct device *dev)
+{
+ struct spi_device *spi = to_spi_device(dev);
+
+ spi_controller_put(spi->controller);
+ kfree(spi->driver_override);
+ free_percpu(spi->pcpu_statistics);
+ kfree(spi);
+}
+
+static ssize_t
+modalias_show(struct device *dev, struct device_attribute *a, char *buf)
+{
+ const struct spi_device *spi = to_spi_device(dev);
+ int len;
+
+ len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
+ if (len != -ENODEV)
+ return len;
+
+ return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
+}
+static DEVICE_ATTR_RO(modalias);
+
+static ssize_t driver_override_store(struct device *dev,
+ struct device_attribute *a,
+ const char *buf, size_t count)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ int ret;
+
+ ret = driver_set_override(dev, &spi->driver_override, buf, count);
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+static ssize_t driver_override_show(struct device *dev,
+ struct device_attribute *a, char *buf)
+{
+ const struct spi_device *spi = to_spi_device(dev);
+ ssize_t len;
+
+ device_lock(dev);
+ len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : "");
+ device_unlock(dev);
+ return len;
+}
+static DEVICE_ATTR_RW(driver_override);
+
+static struct spi_statistics __percpu *spi_alloc_pcpu_stats(struct device *dev)
+{
+ struct spi_statistics __percpu *pcpu_stats;
+
+ if (dev)
+ pcpu_stats = devm_alloc_percpu(dev, struct spi_statistics);
+ else
+ pcpu_stats = alloc_percpu_gfp(struct spi_statistics, GFP_KERNEL);
+
+ if (pcpu_stats) {
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ struct spi_statistics *stat;
+
+ stat = per_cpu_ptr(pcpu_stats, cpu);
+ u64_stats_init(&stat->syncp);
+ }
+ }
+ return pcpu_stats;
+}
+
+#define spi_pcpu_stats_totalize(ret, in, field) \
+do { \
+ int i; \
+ ret = 0; \
+ for_each_possible_cpu(i) { \
+ const struct spi_statistics *pcpu_stats; \
+ u64 inc; \
+ unsigned int start; \
+ pcpu_stats = per_cpu_ptr(in, i); \
+ do { \
+ start = u64_stats_fetch_begin_irq( \
+ &pcpu_stats->syncp); \
+ inc = u64_stats_read(&pcpu_stats->field); \
+ } while (u64_stats_fetch_retry_irq( \
+ &pcpu_stats->syncp, start)); \
+ ret += inc; \
+ } \
+} while (0)
+
+#define SPI_STATISTICS_ATTRS(field, file) \
+static ssize_t spi_controller_##field##_show(struct device *dev, \
+ struct device_attribute *attr, \
+ char *buf) \
+{ \
+ struct spi_controller *ctlr = container_of(dev, \
+ struct spi_controller, dev); \
+ return spi_statistics_##field##_show(ctlr->pcpu_statistics, buf); \
+} \
+static struct device_attribute dev_attr_spi_controller_##field = { \
+ .attr = { .name = file, .mode = 0444 }, \
+ .show = spi_controller_##field##_show, \
+}; \
+static ssize_t spi_device_##field##_show(struct device *dev, \
+ struct device_attribute *attr, \
+ char *buf) \
+{ \
+ struct spi_device *spi = to_spi_device(dev); \
+ return spi_statistics_##field##_show(spi->pcpu_statistics, buf); \
+} \
+static struct device_attribute dev_attr_spi_device_##field = { \
+ .attr = { .name = file, .mode = 0444 }, \
+ .show = spi_device_##field##_show, \
+}
+
+#define SPI_STATISTICS_SHOW_NAME(name, file, field) \
+static ssize_t spi_statistics_##name##_show(struct spi_statistics __percpu *stat, \
+ char *buf) \
+{ \
+ ssize_t len; \
+ u64 val; \
+ spi_pcpu_stats_totalize(val, stat, field); \
+ len = sysfs_emit(buf, "%llu\n", val); \
+ return len; \
+} \
+SPI_STATISTICS_ATTRS(name, file)
+
+#define SPI_STATISTICS_SHOW(field) \
+ SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
+ field)
+
+SPI_STATISTICS_SHOW(messages);
+SPI_STATISTICS_SHOW(transfers);
+SPI_STATISTICS_SHOW(errors);
+SPI_STATISTICS_SHOW(timedout);
+
+SPI_STATISTICS_SHOW(spi_sync);
+SPI_STATISTICS_SHOW(spi_sync_immediate);
+SPI_STATISTICS_SHOW(spi_async);
+
+SPI_STATISTICS_SHOW(bytes);
+SPI_STATISTICS_SHOW(bytes_rx);
+SPI_STATISTICS_SHOW(bytes_tx);
+
+#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
+ SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
+ "transfer_bytes_histo_" number, \
+ transfer_bytes_histo[index])
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
+SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
+
+SPI_STATISTICS_SHOW(transfers_split_maxsize);
+
+static struct attribute *spi_dev_attrs[] = {
+ &dev_attr_modalias.attr,
+ &dev_attr_driver_override.attr,
+ NULL,
+};
+
+static const struct attribute_group spi_dev_group = {
+ .attrs = spi_dev_attrs,
+};
+
+static struct attribute *spi_device_statistics_attrs[] = {
+ &dev_attr_spi_device_messages.attr,
+ &dev_attr_spi_device_transfers.attr,
+ &dev_attr_spi_device_errors.attr,
+ &dev_attr_spi_device_timedout.attr,
+ &dev_attr_spi_device_spi_sync.attr,
+ &dev_attr_spi_device_spi_sync_immediate.attr,
+ &dev_attr_spi_device_spi_async.attr,
+ &dev_attr_spi_device_bytes.attr,
+ &dev_attr_spi_device_bytes_rx.attr,
+ &dev_attr_spi_device_bytes_tx.attr,
+ &dev_attr_spi_device_transfer_bytes_histo0.attr,
+ &dev_attr_spi_device_transfer_bytes_histo1.attr,
+ &dev_attr_spi_device_transfer_bytes_histo2.attr,
+ &dev_attr_spi_device_transfer_bytes_histo3.attr,
+ &dev_attr_spi_device_transfer_bytes_histo4.attr,
+ &dev_attr_spi_device_transfer_bytes_histo5.attr,
+ &dev_attr_spi_device_transfer_bytes_histo6.attr,
+ &dev_attr_spi_device_transfer_bytes_histo7.attr,
+ &dev_attr_spi_device_transfer_bytes_histo8.attr,
+ &dev_attr_spi_device_transfer_bytes_histo9.attr,
+ &dev_attr_spi_device_transfer_bytes_histo10.attr,
+ &dev_attr_spi_device_transfer_bytes_histo11.attr,
+ &dev_attr_spi_device_transfer_bytes_histo12.attr,
+ &dev_attr_spi_device_transfer_bytes_histo13.attr,
+ &dev_attr_spi_device_transfer_bytes_histo14.attr,
+ &dev_attr_spi_device_transfer_bytes_histo15.attr,
+ &dev_attr_spi_device_transfer_bytes_histo16.attr,
+ &dev_attr_spi_device_transfers_split_maxsize.attr,
+ NULL,
+};
+
+static const struct attribute_group spi_device_statistics_group = {
+ .name = "statistics",
+ .attrs = spi_device_statistics_attrs,
+};
+
+static const struct attribute_group *spi_dev_groups[] = {
+ &spi_dev_group,
+ &spi_device_statistics_group,
+ NULL,
+};
+
+static struct attribute *spi_controller_statistics_attrs[] = {
+ &dev_attr_spi_controller_messages.attr,
+ &dev_attr_spi_controller_transfers.attr,
+ &dev_attr_spi_controller_errors.attr,
+ &dev_attr_spi_controller_timedout.attr,
+ &dev_attr_spi_controller_spi_sync.attr,
+ &dev_attr_spi_controller_spi_sync_immediate.attr,
+ &dev_attr_spi_controller_spi_async.attr,
+ &dev_attr_spi_controller_bytes.attr,
+ &dev_attr_spi_controller_bytes_rx.attr,
+ &dev_attr_spi_controller_bytes_tx.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo0.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo1.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo2.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo3.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo4.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo5.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo6.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo7.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo8.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo9.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo10.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo11.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo12.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo13.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo14.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo15.attr,
+ &dev_attr_spi_controller_transfer_bytes_histo16.attr,
+ &dev_attr_spi_controller_transfers_split_maxsize.attr,
+ NULL,
+};
+
+static const struct attribute_group spi_controller_statistics_group = {
+ .name = "statistics",
+ .attrs = spi_controller_statistics_attrs,
+};
+
+static const struct attribute_group *spi_master_groups[] = {
+ &spi_controller_statistics_group,
+ NULL,
+};
+
+static void spi_statistics_add_transfer_stats(struct spi_statistics __percpu *pcpu_stats,
+ struct spi_transfer *xfer,
+ struct spi_controller *ctlr)
+{
+ int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
+ struct spi_statistics *stats;
+
+ if (l2len < 0)
+ l2len = 0;
+
+ get_cpu();
+ stats = this_cpu_ptr(pcpu_stats);
+ u64_stats_update_begin(&stats->syncp);
+
+ u64_stats_inc(&stats->transfers);
+ u64_stats_inc(&stats->transfer_bytes_histo[l2len]);
+
+ u64_stats_add(&stats->bytes, xfer->len);
+ if ((xfer->tx_buf) &&
+ (xfer->tx_buf != ctlr->dummy_tx))
+ u64_stats_add(&stats->bytes_tx, xfer->len);
+ if ((xfer->rx_buf) &&
+ (xfer->rx_buf != ctlr->dummy_rx))
+ u64_stats_add(&stats->bytes_rx, xfer->len);
+
+ u64_stats_update_end(&stats->syncp);
+ put_cpu();
+}
+
+/*
+ * modalias support makes "modprobe $MODALIAS" new-style hotplug work,
+ * and the sysfs version makes coldplug work too.
+ */
+static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, const char *name)
+{
+ while (id->name[0]) {
+ if (!strcmp(name, id->name))
+ return id;
+ id++;
+ }
+ return NULL;
+}
+
+const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
+{
+ const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
+
+ return spi_match_id(sdrv->id_table, sdev->modalias);
+}
+EXPORT_SYMBOL_GPL(spi_get_device_id);
+
+const void *spi_get_device_match_data(const struct spi_device *sdev)
+{
+ const void *match;
+
+ match = device_get_match_data(&sdev->dev);
+ if (match)
+ return match;
+
+ return (const void *)spi_get_device_id(sdev)->driver_data;
+}
+EXPORT_SYMBOL_GPL(spi_get_device_match_data);
+
+static int spi_match_device(struct device *dev, struct device_driver *drv)
+{
+ const struct spi_device *spi = to_spi_device(dev);
+ const struct spi_driver *sdrv = to_spi_driver(drv);
+
+ /* Check override first, and if set, only use the named driver */
+ if (spi->driver_override)
+ return strcmp(spi->driver_override, drv->name) == 0;
+
+ /* Attempt an OF style match */
+ if (of_driver_match_device(dev, drv))
+ return 1;
+
+ /* Then try ACPI */
+ if (acpi_driver_match_device(dev, drv))
+ return 1;
+
+ if (sdrv->id_table)
+ return !!spi_match_id(sdrv->id_table, spi->modalias);
+
+ return strcmp(spi->modalias, drv->name) == 0;
+}
+
+static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+ const struct spi_device *spi = to_spi_device(dev);
+ int rc;
+
+ rc = acpi_device_uevent_modalias(dev, env);
+ if (rc != -ENODEV)
+ return rc;
+
+ return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
+}
+
+static int spi_probe(struct device *dev)
+{
+ const struct spi_driver *sdrv = to_spi_driver(dev->driver);
+ struct spi_device *spi = to_spi_device(dev);
+ int ret;
+
+ ret = of_clk_set_defaults(dev->of_node, false);
+ if (ret)
+ return ret;
+
+ if (dev->of_node) {
+ spi->irq = of_irq_get(dev->of_node, 0);
+ if (spi->irq == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+ if (spi->irq < 0)
+ spi->irq = 0;
+ }
+
+ ret = dev_pm_domain_attach(dev, true);
+ if (ret)
+ return ret;
+
+ if (sdrv->probe) {
+ ret = sdrv->probe(spi);
+ if (ret)
+ dev_pm_domain_detach(dev, true);
+ }
+
+ return ret;
+}
+
+static void spi_remove(struct device *dev)
+{
+ const struct spi_driver *sdrv = to_spi_driver(dev->driver);
+
+ if (sdrv->remove)
+ sdrv->remove(to_spi_device(dev));
+
+ dev_pm_domain_detach(dev, true);
+}
+
+static void spi_shutdown(struct device *dev)
+{
+ if (dev->driver) {
+ const struct spi_driver *sdrv = to_spi_driver(dev->driver);
+
+ if (sdrv->shutdown)
+ sdrv->shutdown(to_spi_device(dev));
+ }
+}
+
+struct bus_type spi_bus_type = {
+ .name = "spi",
+ .dev_groups = spi_dev_groups,
+ .match = spi_match_device,
+ .uevent = spi_uevent,
+ .probe = spi_probe,
+ .remove = spi_remove,
+ .shutdown = spi_shutdown,
+};
+EXPORT_SYMBOL_GPL(spi_bus_type);
+
+/**
+ * __spi_register_driver - register a SPI driver
+ * @owner: owner module of the driver to register
+ * @sdrv: the driver to register
+ * Context: can sleep
+ *
+ * Return: zero on success, else a negative error code.
+ */
+int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
+{
+ sdrv->driver.owner = owner;
+ sdrv->driver.bus = &spi_bus_type;
+
+ /*
+ * For Really Good Reasons we use spi: modaliases not of:
+ * modaliases for DT so module autoloading won't work if we
+ * don't have a spi_device_id as well as a compatible string.
+ */
+ if (sdrv->driver.of_match_table) {
+ const struct of_device_id *of_id;
+
+ for (of_id = sdrv->driver.of_match_table; of_id->compatible[0];
+ of_id++) {
+ const char *of_name;
+
+ /* Strip off any vendor prefix */
+ of_name = strnchr(of_id->compatible,
+ sizeof(of_id->compatible), ',');
+ if (of_name)
+ of_name++;
+ else
+ of_name = of_id->compatible;
+
+ if (sdrv->id_table) {
+ const struct spi_device_id *spi_id;
+
+ spi_id = spi_match_id(sdrv->id_table, of_name);
+ if (spi_id)
+ continue;
+ } else {
+ if (strcmp(sdrv->driver.name, of_name) == 0)
+ continue;
+ }
+
+ pr_warn("SPI driver %s has no spi_device_id for %s\n",
+ sdrv->driver.name, of_id->compatible);
+ }
+ }
+
+ return driver_register(&sdrv->driver);
+}
+EXPORT_SYMBOL_GPL(__spi_register_driver);
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * SPI devices should normally not be created by SPI device drivers; that
+ * would make them board-specific. Similarly with SPI controller drivers.
+ * Device registration normally goes into like arch/.../mach.../board-YYY.c
+ * with other readonly (flashable) information about mainboard devices.
+ */
+
+struct boardinfo {
+ struct list_head list;
+ struct spi_board_info board_info;
+};
+
+static LIST_HEAD(board_list);
+static LIST_HEAD(spi_controller_list);
+
+/*
+ * Used to protect add/del operation for board_info list and
+ * spi_controller list, and their matching process also used
+ * to protect object of type struct idr.
+ */
+static DEFINE_MUTEX(board_lock);
+
+/**
+ * spi_alloc_device - Allocate a new SPI device
+ * @ctlr: Controller to which device is connected
+ * Context: can sleep
+ *
+ * Allows a driver to allocate and initialize a spi_device without
+ * registering it immediately. This allows a driver to directly
+ * fill the spi_device with device parameters before calling
+ * spi_add_device() on it.
+ *
+ * Caller is responsible to call spi_add_device() on the returned
+ * spi_device structure to add it to the SPI controller. If the caller
+ * needs to discard the spi_device without adding it, then it should
+ * call spi_dev_put() on it.
+ *
+ * Return: a pointer to the new device, or NULL.
+ */
+struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
+{
+ struct spi_device *spi;
+
+ if (!spi_controller_get(ctlr))
+ return NULL;
+
+ spi = kzalloc(sizeof(*spi), GFP_KERNEL);
+ if (!spi) {
+ spi_controller_put(ctlr);
+ return NULL;
+ }
+
+ spi->pcpu_statistics = spi_alloc_pcpu_stats(NULL);
+ if (!spi->pcpu_statistics) {
+ kfree(spi);
+ spi_controller_put(ctlr);
+ return NULL;
+ }
+
+ spi->master = spi->controller = ctlr;
+ spi->dev.parent = &ctlr->dev;
+ spi->dev.bus = &spi_bus_type;
+ spi->dev.release = spidev_release;
+ spi->mode = ctlr->buswidth_override_bits;
+
+ device_initialize(&spi->dev);
+ return spi;
+}
+EXPORT_SYMBOL_GPL(spi_alloc_device);
+
+static void spi_dev_set_name(struct spi_device *spi)
+{
+ struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
+
+ if (adev) {
+ dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
+ return;
+ }
+
+ dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
+ spi_get_chipselect(spi, 0));
+}
+
+static int spi_dev_check(struct device *dev, void *data)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ struct spi_device *new_spi = data;
+
+ if (spi->controller == new_spi->controller &&
+ spi_get_chipselect(spi, 0) == spi_get_chipselect(new_spi, 0))
+ return -EBUSY;
+ return 0;
+}
+
+static void spi_cleanup(struct spi_device *spi)
+{
+ if (spi->controller->cleanup)
+ spi->controller->cleanup(spi);
+}
+
+static int __spi_add_device(struct spi_device *spi)
+{
+ struct spi_controller *ctlr = spi->controller;
+ struct device *dev = ctlr->dev.parent;
+ int status;
+
+ /*
+ * We need to make sure there's no other device with this
+ * chipselect **BEFORE** we call setup(), else we'll trash
+ * its configuration.
+ */
+ status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
+ if (status) {
+ dev_err(dev, "chipselect %d already in use\n",
+ spi_get_chipselect(spi, 0));
+ return status;
+ }
+
+ /* Controller may unregister concurrently */
+ if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
+ !device_is_registered(&ctlr->dev)) {
+ return -ENODEV;
+ }
+
+ if (ctlr->cs_gpiods)
+ spi_set_csgpiod(spi, 0, ctlr->cs_gpiods[spi_get_chipselect(spi, 0)]);
+
+ /*
+ * Drivers may modify this initial i/o setup, but will
+ * normally rely on the device being setup. Devices
+ * using SPI_CS_HIGH can't coexist well otherwise...
+ */
+ status = spi_setup(spi);
+ if (status < 0) {
+ dev_err(dev, "can't setup %s, status %d\n",
+ dev_name(&spi->dev), status);
+ return status;
+ }
+
+ /* Device may be bound to an active driver when this returns */
+ status = device_add(&spi->dev);
+ if (status < 0) {
+ dev_err(dev, "can't add %s, status %d\n",
+ dev_name(&spi->dev), status);
+ spi_cleanup(spi);
+ } else {
+ dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
+ }
+
+ return status;
+}
+
+/**
+ * spi_add_device - Add spi_device allocated with spi_alloc_device
+ * @spi: spi_device to register
+ *
+ * Companion function to spi_alloc_device. Devices allocated with
+ * spi_alloc_device can be added onto the spi bus with this function.
+ *
+ * Return: 0 on success; negative errno on failure
+ */
+int spi_add_device(struct spi_device *spi)
+{
+ struct spi_controller *ctlr = spi->controller;
+ struct device *dev = ctlr->dev.parent;
+ int status;
+
+ /* Chipselects are numbered 0..max; validate. */
+ if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
+ dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
+ ctlr->num_chipselect);
+ return -EINVAL;
+ }
+
+ /* Set the bus ID string */
+ spi_dev_set_name(spi);
+
+ mutex_lock(&ctlr->add_lock);
+ status = __spi_add_device(spi);
+ mutex_unlock(&ctlr->add_lock);
+ return status;
+}
+EXPORT_SYMBOL_GPL(spi_add_device);
+
+static int spi_add_device_locked(struct spi_device *spi)
+{
+ struct spi_controller *ctlr = spi->controller;
+ struct device *dev = ctlr->dev.parent;
+
+ /* Chipselects are numbered 0..max; validate. */
+ if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
+ dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
+ ctlr->num_chipselect);
+ return -EINVAL;
+ }
+
+ /* Set the bus ID string */
+ spi_dev_set_name(spi);
+
+ WARN_ON(!mutex_is_locked(&ctlr->add_lock));
+ return __spi_add_device(spi);
+}
+
+/**
+ * spi_new_device - instantiate one new SPI device
+ * @ctlr: Controller to which device is connected
+ * @chip: Describes the SPI device
+ * Context: can sleep
+ *
+ * On typical mainboards, this is purely internal; and it's not needed
+ * after board init creates the hard-wired devices. Some development
+ * platforms may not be able to use spi_register_board_info though, and
+ * this is exported so that for example a USB or parport based adapter
+ * driver could add devices (which it would learn about out-of-band).
+ *
+ * Return: the new device, or NULL.
+ */
+struct spi_device *spi_new_device(struct spi_controller *ctlr,
+ struct spi_board_info *chip)
+{
+ struct spi_device *proxy;
+ int status;
+
+ /*
+ * NOTE: caller did any chip->bus_num checks necessary.
+ *
+ * Also, unless we change the return value convention to use
+ * error-or-pointer (not NULL-or-pointer), troubleshootability
+ * suggests syslogged diagnostics are best here (ugh).
+ */
+
+ proxy = spi_alloc_device(ctlr);
+ if (!proxy)
+ return NULL;
+
+ WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
+
+ spi_set_chipselect(proxy, 0, chip->chip_select);
+ proxy->max_speed_hz = chip->max_speed_hz;
+ proxy->mode = chip->mode;
+ proxy->irq = chip->irq;
+ strscpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
+ proxy->dev.platform_data = (void *) chip->platform_data;
+ proxy->controller_data = chip->controller_data;
+ proxy->controller_state = NULL;
+
+ if (chip->swnode) {
+ status = device_add_software_node(&proxy->dev, chip->swnode);
+ if (status) {
+ dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n",
+ chip->modalias, status);
+ goto err_dev_put;
+ }
+ }
+
+ status = spi_add_device(proxy);
+ if (status < 0)
+ goto err_dev_put;
+
+ return proxy;
+
+err_dev_put:
+ device_remove_software_node(&proxy->dev);
+ spi_dev_put(proxy);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(spi_new_device);
+
+/**
+ * spi_unregister_device - unregister a single SPI device
+ * @spi: spi_device to unregister
+ *
+ * Start making the passed SPI device vanish. Normally this would be handled
+ * by spi_unregister_controller().
+ */
+void spi_unregister_device(struct spi_device *spi)
+{
+ if (!spi)
+ return;
+
+ if (spi->dev.of_node) {
+ of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
+ of_node_put(spi->dev.of_node);
+ }
+ if (ACPI_COMPANION(&spi->dev))
+ acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
+ device_remove_software_node(&spi->dev);
+ device_del(&spi->dev);
+ spi_cleanup(spi);
+ put_device(&spi->dev);
+}
+EXPORT_SYMBOL_GPL(spi_unregister_device);
+
+static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
+ struct spi_board_info *bi)
+{
+ struct spi_device *dev;
+
+ if (ctlr->bus_num != bi->bus_num)
+ return;
+
+ dev = spi_new_device(ctlr, bi);
+ if (!dev)
+ dev_err(ctlr->dev.parent, "can't create new device for %s\n",
+ bi->modalias);
+}
+
+/**
+ * spi_register_board_info - register SPI devices for a given board
+ * @info: array of chip descriptors
+ * @n: how many descriptors are provided
+ * Context: can sleep
+ *
+ * Board-specific early init code calls this (probably during arch_initcall)
+ * with segments of the SPI device table. Any device nodes are created later,
+ * after the relevant parent SPI controller (bus_num) is defined. We keep
+ * this table of devices forever, so that reloading a controller driver will
+ * not make Linux forget about these hard-wired devices.
+ *
+ * Other code can also call this, e.g. a particular add-on board might provide
+ * SPI devices through its expansion connector, so code initializing that board
+ * would naturally declare its SPI devices.
+ *
+ * The board info passed can safely be __initdata ... but be careful of
+ * any embedded pointers (platform_data, etc), they're copied as-is.
+ *
+ * Return: zero on success, else a negative error code.
+ */
+int spi_register_board_info(struct spi_board_info const *info, unsigned n)
+{
+ struct boardinfo *bi;
+ int i;
+
+ if (!n)
+ return 0;
+
+ bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
+ if (!bi)
+ return -ENOMEM;
+
+ for (i = 0; i < n; i++, bi++, info++) {
+ struct spi_controller *ctlr;
+
+ memcpy(&bi->board_info, info, sizeof(*info));
+
+ mutex_lock(&board_lock);
+ list_add_tail(&bi->list, &board_list);
+ list_for_each_entry(ctlr, &spi_controller_list, list)
+ spi_match_controller_to_boardinfo(ctlr,
+ &bi->board_info);
+ mutex_unlock(&board_lock);
+ }
+
+ return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* Core methods for SPI resource management */
+
+/**
+ * spi_res_alloc - allocate a spi resource that is life-cycle managed
+ * during the processing of a spi_message while using
+ * spi_transfer_one
+ * @spi: the spi device for which we allocate memory
+ * @release: the release code to execute for this resource
+ * @size: size to alloc and return
+ * @gfp: GFP allocation flags
+ *
+ * Return: the pointer to the allocated data
+ *
+ * This may get enhanced in the future to allocate from a memory pool
+ * of the @spi_device or @spi_controller to avoid repeated allocations.
+ */
+static void *spi_res_alloc(struct spi_device *spi, spi_res_release_t release,
+ size_t size, gfp_t gfp)
+{
+ struct spi_res *sres;
+
+ sres = kzalloc(sizeof(*sres) + size, gfp);
+ if (!sres)
+ return NULL;
+
+ INIT_LIST_HEAD(&sres->entry);
+ sres->release = release;
+
+ return sres->data;
+}
+
+/**
+ * spi_res_free - free an spi resource
+ * @res: pointer to the custom data of a resource
+ */
+static void spi_res_free(void *res)
+{
+ struct spi_res *sres = container_of(res, struct spi_res, data);
+
+ if (!res)
+ return;
+
+ WARN_ON(!list_empty(&sres->entry));
+ kfree(sres);
+}
+
+/**
+ * spi_res_add - add a spi_res to the spi_message
+ * @message: the spi message
+ * @res: the spi_resource
+ */
+static void spi_res_add(struct spi_message *message, void *res)
+{
+ struct spi_res *sres = container_of(res, struct spi_res, data);
+
+ WARN_ON(!list_empty(&sres->entry));
+ list_add_tail(&sres->entry, &message->resources);
+}
+
+/**
+ * spi_res_release - release all spi resources for this message
+ * @ctlr: the @spi_controller
+ * @message: the @spi_message
+ */
+static void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
+{
+ struct spi_res *res, *tmp;
+
+ list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
+ if (res->release)
+ res->release(ctlr, message, res->data);
+
+ list_del(&res->entry);
+
+ kfree(res);
+ }
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
+{
+ bool activate = enable;
+
+ /*
+ * Avoid calling into the driver (or doing delays) if the chip select
+ * isn't actually changing from the last time this was called.
+ */
+ if (!force && ((enable && spi->controller->last_cs == spi_get_chipselect(spi, 0)) ||
+ (!enable && spi->controller->last_cs != spi_get_chipselect(spi, 0))) &&
+ (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
+ return;
+
+ trace_spi_set_cs(spi, activate);
+
+ spi->controller->last_cs = enable ? spi_get_chipselect(spi, 0) : -1;
+ spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
+
+ if ((spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) && !activate)
+ spi_delay_exec(&spi->cs_hold, NULL);
+
+ if (spi->mode & SPI_CS_HIGH)
+ enable = !enable;
+
+ if (spi_get_csgpiod(spi, 0)) {
+ if (!(spi->mode & SPI_NO_CS)) {
+ /*
+ * Historically ACPI has no means of the GPIO polarity and
+ * thus the SPISerialBus() resource defines it on the per-chip
+ * basis. In order to avoid a chain of negations, the GPIO
+ * polarity is considered being Active High. Even for the cases
+ * when _DSD() is involved (in the updated versions of ACPI)
+ * the GPIO CS polarity must be defined Active High to avoid
+ * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
+ * into account.
+ */
+ if (has_acpi_companion(&spi->dev))
+ gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), !enable);
+ else
+ /* Polarity handled by GPIO library */
+ gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), activate);
+ }
+ /* Some SPI masters need both GPIO CS & slave_select */
+ if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
+ spi->controller->set_cs)
+ spi->controller->set_cs(spi, !enable);
+ } else if (spi->controller->set_cs) {
+ spi->controller->set_cs(spi, !enable);
+ }
+
+ if (spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) {
+ if (activate)
+ spi_delay_exec(&spi->cs_setup, NULL);
+ else
+ spi_delay_exec(&spi->cs_inactive, NULL);
+ }
+}
+
+#ifdef CONFIG_HAS_DMA
+static int spi_map_buf_attrs(struct spi_controller *ctlr, struct device *dev,
+ struct sg_table *sgt, void *buf, size_t len,
+ enum dma_data_direction dir, unsigned long attrs)
+{
+ const bool vmalloced_buf = is_vmalloc_addr(buf);
+ unsigned int max_seg_size = dma_get_max_seg_size(dev);
+#ifdef CONFIG_HIGHMEM
+ const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
+ (unsigned long)buf < (PKMAP_BASE +
+ (LAST_PKMAP * PAGE_SIZE)));
+#else
+ const bool kmap_buf = false;
+#endif
+ int desc_len;
+ int sgs;
+ struct page *vm_page;
+ struct scatterlist *sg;
+ void *sg_buf;
+ size_t min;
+ int i, ret;
+
+ if (vmalloced_buf || kmap_buf) {
+ desc_len = min_t(unsigned long, max_seg_size, PAGE_SIZE);
+ sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
+ } else if (virt_addr_valid(buf)) {
+ desc_len = min_t(size_t, max_seg_size, ctlr->max_dma_len);
+ sgs = DIV_ROUND_UP(len, desc_len);
+ } else {
+ return -EINVAL;
+ }
+
+ ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
+ if (ret != 0)
+ return ret;
+
+ sg = &sgt->sgl[0];
+ for (i = 0; i < sgs; i++) {
+
+ if (vmalloced_buf || kmap_buf) {
+ /*
+ * Next scatterlist entry size is the minimum between
+ * the desc_len and the remaining buffer length that
+ * fits in a page.
+ */
+ min = min_t(size_t, desc_len,
+ min_t(size_t, len,
+ PAGE_SIZE - offset_in_page(buf)));
+ if (vmalloced_buf)
+ vm_page = vmalloc_to_page(buf);
+ else
+ vm_page = kmap_to_page(buf);
+ if (!vm_page) {
+ sg_free_table(sgt);
+ return -ENOMEM;
+ }
+ sg_set_page(sg, vm_page,
+ min, offset_in_page(buf));
+ } else {
+ min = min_t(size_t, len, desc_len);
+ sg_buf = buf;
+ sg_set_buf(sg, sg_buf, min);
+ }
+
+ buf += min;
+ len -= min;
+ sg = sg_next(sg);
+ }
+
+ ret = dma_map_sgtable(dev, sgt, dir, attrs);
+ if (ret < 0) {
+ sg_free_table(sgt);
+ return ret;
+ }
+
+ return 0;
+}
+
+int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
+ struct sg_table *sgt, void *buf, size_t len,
+ enum dma_data_direction dir)
+{
+ return spi_map_buf_attrs(ctlr, dev, sgt, buf, len, dir, 0);
+}
+
+static void spi_unmap_buf_attrs(struct spi_controller *ctlr,
+ struct device *dev, struct sg_table *sgt,
+ enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ if (sgt->orig_nents) {
+ dma_unmap_sgtable(dev, sgt, dir, attrs);
+ sg_free_table(sgt);
+ sgt->orig_nents = 0;
+ sgt->nents = 0;
+ }
+}
+
+void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
+ struct sg_table *sgt, enum dma_data_direction dir)
+{
+ spi_unmap_buf_attrs(ctlr, dev, sgt, dir, 0);
+}
+
+static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
+{
+ struct device *tx_dev, *rx_dev;
+ struct spi_transfer *xfer;
+ int ret;
+
+ if (!ctlr->can_dma)
+ return 0;
+
+ if (ctlr->dma_tx)
+ tx_dev = ctlr->dma_tx->device->dev;
+ else if (ctlr->dma_map_dev)
+ tx_dev = ctlr->dma_map_dev;
+ else
+ tx_dev = ctlr->dev.parent;
+
+ if (ctlr->dma_rx)
+ rx_dev = ctlr->dma_rx->device->dev;
+ else if (ctlr->dma_map_dev)
+ rx_dev = ctlr->dma_map_dev;
+ else
+ rx_dev = ctlr->dev.parent;
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ /* The sync is done before each transfer. */
+ unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC;
+
+ if (!ctlr->can_dma(ctlr, msg->spi, xfer))
+ continue;
+
+ if (xfer->tx_buf != NULL) {
+ ret = spi_map_buf_attrs(ctlr, tx_dev, &xfer->tx_sg,
+ (void *)xfer->tx_buf,
+ xfer->len, DMA_TO_DEVICE,
+ attrs);
+ if (ret != 0)
+ return ret;
+ }
+
+ if (xfer->rx_buf != NULL) {
+ ret = spi_map_buf_attrs(ctlr, rx_dev, &xfer->rx_sg,
+ xfer->rx_buf, xfer->len,
+ DMA_FROM_DEVICE, attrs);
+ if (ret != 0) {
+ spi_unmap_buf_attrs(ctlr, tx_dev,
+ &xfer->tx_sg, DMA_TO_DEVICE,
+ attrs);
+
+ return ret;
+ }
+ }
+ }
+
+ ctlr->cur_rx_dma_dev = rx_dev;
+ ctlr->cur_tx_dma_dev = tx_dev;
+ ctlr->cur_msg_mapped = true;
+
+ return 0;
+}
+
+static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
+{
+ struct device *rx_dev = ctlr->cur_rx_dma_dev;
+ struct device *tx_dev = ctlr->cur_tx_dma_dev;
+ struct spi_transfer *xfer;
+
+ if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
+ return 0;
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ /* The sync has already been done after each transfer. */
+ unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC;
+
+ if (!ctlr->can_dma(ctlr, msg->spi, xfer))
+ continue;
+
+ spi_unmap_buf_attrs(ctlr, rx_dev, &xfer->rx_sg,
+ DMA_FROM_DEVICE, attrs);
+ spi_unmap_buf_attrs(ctlr, tx_dev, &xfer->tx_sg,
+ DMA_TO_DEVICE, attrs);
+ }
+
+ ctlr->cur_msg_mapped = false;
+
+ return 0;
+}
+
+static void spi_dma_sync_for_device(struct spi_controller *ctlr,
+ struct spi_transfer *xfer)
+{
+ struct device *rx_dev = ctlr->cur_rx_dma_dev;
+ struct device *tx_dev = ctlr->cur_tx_dma_dev;
+
+ if (!ctlr->cur_msg_mapped)
+ return;
+
+ if (xfer->tx_sg.orig_nents)
+ dma_sync_sgtable_for_device(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
+ if (xfer->rx_sg.orig_nents)
+ dma_sync_sgtable_for_device(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
+}
+
+static void spi_dma_sync_for_cpu(struct spi_controller *ctlr,
+ struct spi_transfer *xfer)
+{
+ struct device *rx_dev = ctlr->cur_rx_dma_dev;
+ struct device *tx_dev = ctlr->cur_tx_dma_dev;
+
+ if (!ctlr->cur_msg_mapped)
+ return;
+
+ if (xfer->rx_sg.orig_nents)
+ dma_sync_sgtable_for_cpu(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
+ if (xfer->tx_sg.orig_nents)
+ dma_sync_sgtable_for_cpu(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
+}
+#else /* !CONFIG_HAS_DMA */
+static inline int __spi_map_msg(struct spi_controller *ctlr,
+ struct spi_message *msg)
+{
+ return 0;
+}
+
+static inline int __spi_unmap_msg(struct spi_controller *ctlr,
+ struct spi_message *msg)
+{
+ return 0;
+}
+
+static void spi_dma_sync_for_device(struct spi_controller *ctrl,
+ struct spi_transfer *xfer)
+{
+}
+
+static void spi_dma_sync_for_cpu(struct spi_controller *ctrl,
+ struct spi_transfer *xfer)
+{
+}
+#endif /* !CONFIG_HAS_DMA */
+
+static inline int spi_unmap_msg(struct spi_controller *ctlr,
+ struct spi_message *msg)
+{
+ struct spi_transfer *xfer;
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ /*
+ * Restore the original value of tx_buf or rx_buf if they are
+ * NULL.
+ */
+ if (xfer->tx_buf == ctlr->dummy_tx)
+ xfer->tx_buf = NULL;
+ if (xfer->rx_buf == ctlr->dummy_rx)
+ xfer->rx_buf = NULL;
+ }
+
+ return __spi_unmap_msg(ctlr, msg);
+}
+
+static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
+{
+ struct spi_transfer *xfer;
+ void *tmp;
+ unsigned int max_tx, max_rx;
+
+ if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
+ && !(msg->spi->mode & SPI_3WIRE)) {
+ max_tx = 0;
+ max_rx = 0;
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
+ !xfer->tx_buf)
+ max_tx = max(xfer->len, max_tx);
+ if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
+ !xfer->rx_buf)
+ max_rx = max(xfer->len, max_rx);
+ }
+
+ if (max_tx) {
+ tmp = krealloc(ctlr->dummy_tx, max_tx,
+ GFP_KERNEL | GFP_DMA | __GFP_ZERO);
+ if (!tmp)
+ return -ENOMEM;
+ ctlr->dummy_tx = tmp;
+ }
+
+ if (max_rx) {
+ tmp = krealloc(ctlr->dummy_rx, max_rx,
+ GFP_KERNEL | GFP_DMA);
+ if (!tmp)
+ return -ENOMEM;
+ ctlr->dummy_rx = tmp;
+ }
+
+ if (max_tx || max_rx) {
+ list_for_each_entry(xfer, &msg->transfers,
+ transfer_list) {
+ if (!xfer->len)
+ continue;
+ if (!xfer->tx_buf)
+ xfer->tx_buf = ctlr->dummy_tx;
+ if (!xfer->rx_buf)
+ xfer->rx_buf = ctlr->dummy_rx;
+ }
+ }
+ }
+
+ return __spi_map_msg(ctlr, msg);
+}
+
+static int spi_transfer_wait(struct spi_controller *ctlr,
+ struct spi_message *msg,
+ struct spi_transfer *xfer)
+{
+ struct spi_statistics __percpu *statm = ctlr->pcpu_statistics;
+ struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics;
+ u32 speed_hz = xfer->speed_hz;
+ unsigned long long ms;
+
+ if (spi_controller_is_slave(ctlr)) {
+ if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
+ dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
+ return -EINTR;
+ }
+ } else {
+ if (!speed_hz)
+ speed_hz = 100000;
+
+ /*
+ * For each byte we wait for 8 cycles of the SPI clock.
+ * Since speed is defined in Hz and we want milliseconds,
+ * use respective multiplier, but before the division,
+ * otherwise we may get 0 for short transfers.
+ */
+ ms = 8LL * MSEC_PER_SEC * xfer->len;
+ do_div(ms, speed_hz);
+
+ /*
+ * Increase it twice and add 200 ms tolerance, use
+ * predefined maximum in case of overflow.
+ */
+ ms += ms + 200;
+ if (ms > UINT_MAX)
+ ms = UINT_MAX;
+
+ ms = wait_for_completion_timeout(&ctlr->xfer_completion,
+ msecs_to_jiffies(ms));
+
+ if (ms == 0) {
+ SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
+ SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
+ dev_err(&msg->spi->dev,
+ "SPI transfer timed out\n");
+ return -ETIMEDOUT;
+ }
+ }
+
+ return 0;
+}
+
+static void _spi_transfer_delay_ns(u32 ns)
+{
+ if (!ns)
+ return;
+ if (ns <= NSEC_PER_USEC) {
+ ndelay(ns);
+ } else {
+ u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC);
+
+ if (us <= 10)
+ udelay(us);
+ else
+ usleep_range(us, us + DIV_ROUND_UP(us, 10));
+ }
+}
+
+int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
+{
+ u32 delay = _delay->value;
+ u32 unit = _delay->unit;
+ u32 hz;
+
+ if (!delay)
+ return 0;
+
+ switch (unit) {
+ case SPI_DELAY_UNIT_USECS:
+ delay *= NSEC_PER_USEC;
+ break;
+ case SPI_DELAY_UNIT_NSECS:
+ /* Nothing to do here */
+ break;
+ case SPI_DELAY_UNIT_SCK:
+ /* Clock cycles need to be obtained from spi_transfer */
+ if (!xfer)
+ return -EINVAL;
+ /*
+ * If there is unknown effective speed, approximate it
+ * by underestimating with half of the requested hz.
+ */
+ hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
+ if (!hz)
+ return -EINVAL;
+
+ /* Convert delay to nanoseconds */
+ delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return delay;
+}
+EXPORT_SYMBOL_GPL(spi_delay_to_ns);
+
+int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
+{
+ int delay;
+
+ might_sleep();
+
+ if (!_delay)
+ return -EINVAL;
+
+ delay = spi_delay_to_ns(_delay, xfer);
+ if (delay < 0)
+ return delay;
+
+ _spi_transfer_delay_ns(delay);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(spi_delay_exec);
+
+static void _spi_transfer_cs_change_delay(struct spi_message *msg,
+ struct spi_transfer *xfer)
+{
+ u32 default_delay_ns = 10 * NSEC_PER_USEC;
+ u32 delay = xfer->cs_change_delay.value;
+ u32 unit = xfer->cs_change_delay.unit;
+ int ret;
+
+ /* Return early on "fast" mode - for everything but USECS */
+ if (!delay) {
+ if (unit == SPI_DELAY_UNIT_USECS)
+ _spi_transfer_delay_ns(default_delay_ns);
+ return;
+ }
+
+ ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
+ if (ret) {
+ dev_err_once(&msg->spi->dev,
+ "Use of unsupported delay unit %i, using default of %luus\n",
+ unit, default_delay_ns / NSEC_PER_USEC);
+ _spi_transfer_delay_ns(default_delay_ns);
+ }
+}
+
+/*
+ * spi_transfer_one_message - Default implementation of transfer_one_message()
+ *
+ * This is a standard implementation of transfer_one_message() for
+ * drivers which implement a transfer_one() operation. It provides
+ * standard handling of delays and chip select management.
+ */
+static int spi_transfer_one_message(struct spi_controller *ctlr,
+ struct spi_message *msg)
+{
+ struct spi_transfer *xfer;
+ bool keep_cs = false;
+ int ret = 0;
+ struct spi_statistics __percpu *statm = ctlr->pcpu_statistics;
+ struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics;
+
+ xfer = list_first_entry(&msg->transfers, struct spi_transfer, transfer_list);
+ spi_set_cs(msg->spi, !xfer->cs_off, false);
+
+ SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
+ SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ trace_spi_transfer_start(msg, xfer);
+
+ spi_statistics_add_transfer_stats(statm, xfer, ctlr);
+ spi_statistics_add_transfer_stats(stats, xfer, ctlr);
+
+ if (!ctlr->ptp_sts_supported) {
+ xfer->ptp_sts_word_pre = 0;
+ ptp_read_system_prets(xfer->ptp_sts);
+ }
+
+ if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) {
+ reinit_completion(&ctlr->xfer_completion);
+
+fallback_pio:
+ spi_dma_sync_for_device(ctlr, xfer);
+ ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
+ if (ret < 0) {
+ spi_dma_sync_for_cpu(ctlr, xfer);
+
+ if (ctlr->cur_msg_mapped &&
+ (xfer->error & SPI_TRANS_FAIL_NO_START)) {
+ __spi_unmap_msg(ctlr, msg);
+ ctlr->fallback = true;
+ xfer->error &= ~SPI_TRANS_FAIL_NO_START;
+ goto fallback_pio;
+ }
+
+ SPI_STATISTICS_INCREMENT_FIELD(statm,
+ errors);
+ SPI_STATISTICS_INCREMENT_FIELD(stats,
+ errors);
+ dev_err(&msg->spi->dev,
+ "SPI transfer failed: %d\n", ret);
+ goto out;
+ }
+
+ if (ret > 0) {
+ ret = spi_transfer_wait(ctlr, msg, xfer);
+ if (ret < 0)
+ msg->status = ret;
+ }
+
+ spi_dma_sync_for_cpu(ctlr, xfer);
+ } else {
+ if (xfer->len)
+ dev_err(&msg->spi->dev,
+ "Bufferless transfer has length %u\n",
+ xfer->len);
+ }
+
+ if (!ctlr->ptp_sts_supported) {
+ ptp_read_system_postts(xfer->ptp_sts);
+ xfer->ptp_sts_word_post = xfer->len;
+ }
+
+ trace_spi_transfer_stop(msg, xfer);
+
+ if (msg->status != -EINPROGRESS)
+ goto out;
+
+ spi_transfer_delay_exec(xfer);
+
+ if (xfer->cs_change) {
+ if (list_is_last(&xfer->transfer_list,
+ &msg->transfers)) {
+ keep_cs = true;
+ } else {
+ if (!xfer->cs_off)
+ spi_set_cs(msg->spi, false, false);
+ _spi_transfer_cs_change_delay(msg, xfer);
+ if (!list_next_entry(xfer, transfer_list)->cs_off)
+ spi_set_cs(msg->spi, true, false);
+ }
+ } else if (!list_is_last(&xfer->transfer_list, &msg->transfers) &&
+ xfer->cs_off != list_next_entry(xfer, transfer_list)->cs_off) {
+ spi_set_cs(msg->spi, xfer->cs_off, false);
+ }
+
+ msg->actual_length += xfer->len;
+ }
+
+out:
+ if (ret != 0 || !keep_cs)
+ spi_set_cs(msg->spi, false, false);
+
+ if (msg->status == -EINPROGRESS)
+ msg->status = ret;
+
+ if (msg->status && ctlr->handle_err)
+ ctlr->handle_err(ctlr, msg);
+
+ spi_finalize_current_message(ctlr);
+
+ return ret;
+}
+
+/**
+ * spi_finalize_current_transfer - report completion of a transfer
+ * @ctlr: the controller reporting completion
+ *
+ * Called by SPI drivers using the core transfer_one_message()
+ * implementation to notify it that the current interrupt driven
+ * transfer has finished and the next one may be scheduled.
+ */
+void spi_finalize_current_transfer(struct spi_controller *ctlr)
+{
+ complete(&ctlr->xfer_completion);
+}
+EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
+
+static void spi_idle_runtime_pm(struct spi_controller *ctlr)
+{
+ if (ctlr->auto_runtime_pm) {
+ pm_runtime_mark_last_busy(ctlr->dev.parent);
+ pm_runtime_put_autosuspend(ctlr->dev.parent);
+ }
+}
+
+static int __spi_pump_transfer_message(struct spi_controller *ctlr,
+ struct spi_message *msg, bool was_busy)
+{
+ struct spi_transfer *xfer;
+ int ret;
+
+ if (!was_busy && ctlr->auto_runtime_pm) {
+ ret = pm_runtime_get_sync(ctlr->dev.parent);
+ if (ret < 0) {
+ pm_runtime_put_noidle(ctlr->dev.parent);
+ dev_err(&ctlr->dev, "Failed to power device: %d\n",
+ ret);
+
+ msg->status = ret;
+ spi_finalize_current_message(ctlr);
+
+ return ret;
+ }
+ }
+
+ if (!was_busy)
+ trace_spi_controller_busy(ctlr);
+
+ if (!was_busy && ctlr->prepare_transfer_hardware) {
+ ret = ctlr->prepare_transfer_hardware(ctlr);
+ if (ret) {
+ dev_err(&ctlr->dev,
+ "failed to prepare transfer hardware: %d\n",
+ ret);
+
+ if (ctlr->auto_runtime_pm)
+ pm_runtime_put(ctlr->dev.parent);
+
+ msg->status = ret;
+ spi_finalize_current_message(ctlr);
+
+ return ret;
+ }
+ }
+
+ trace_spi_message_start(msg);
+
+ ret = spi_split_transfers_maxsize(ctlr, msg,
+ spi_max_transfer_size(msg->spi),
+ GFP_KERNEL | GFP_DMA);
+ if (ret) {
+ msg->status = ret;
+ spi_finalize_current_message(ctlr);
+ return ret;
+ }
+
+ if (ctlr->prepare_message) {
+ ret = ctlr->prepare_message(ctlr, msg);
+ if (ret) {
+ dev_err(&ctlr->dev, "failed to prepare message: %d\n",
+ ret);
+ msg->status = ret;
+ spi_finalize_current_message(ctlr);
+ return ret;
+ }
+ msg->prepared = true;
+ }
+
+ ret = spi_map_msg(ctlr, msg);
+ if (ret) {
+ msg->status = ret;
+ spi_finalize_current_message(ctlr);
+ return ret;
+ }
+
+ if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ xfer->ptp_sts_word_pre = 0;
+ ptp_read_system_prets(xfer->ptp_sts);
+ }
+ }
+
+ /*
+ * Drivers implementation of transfer_one_message() must arrange for
+ * spi_finalize_current_message() to get called. Most drivers will do
+ * this in the calling context, but some don't. For those cases, a
+ * completion is used to guarantee that this function does not return
+ * until spi_finalize_current_message() is done accessing
+ * ctlr->cur_msg.
+ * Use of the following two flags enable to opportunistically skip the
+ * use of the completion since its use involves expensive spin locks.
+ * In case of a race with the context that calls
+ * spi_finalize_current_message() the completion will always be used,
+ * due to strict ordering of these flags using barriers.
+ */
+ WRITE_ONCE(ctlr->cur_msg_incomplete, true);
+ WRITE_ONCE(ctlr->cur_msg_need_completion, false);
+ reinit_completion(&ctlr->cur_msg_completion);
+ smp_wmb(); /* Make these available to spi_finalize_current_message() */
+
+ ret = ctlr->transfer_one_message(ctlr, msg);
+ if (ret) {
+ dev_err(&ctlr->dev,
+ "failed to transfer one message from queue\n");
+ return ret;
+ }
+
+ WRITE_ONCE(ctlr->cur_msg_need_completion, true);
+ smp_mb(); /* See spi_finalize_current_message()... */
+ if (READ_ONCE(ctlr->cur_msg_incomplete))
+ wait_for_completion(&ctlr->cur_msg_completion);
+
+ return 0;
+}
+
+/**
+ * __spi_pump_messages - function which processes spi message queue
+ * @ctlr: controller to process queue for
+ * @in_kthread: true if we are in the context of the message pump thread
+ *
+ * This function checks if there is any spi message in the queue that
+ * needs processing and if so call out to the driver to initialize hardware
+ * and transfer each message.
+ *
+ * Note that it is called both from the kthread itself and also from
+ * inside spi_sync(); the queue extraction handling at the top of the
+ * function should deal with this safely.
+ */
+static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
+{
+ struct spi_message *msg;
+ bool was_busy = false;
+ unsigned long flags;
+ int ret;
+
+ /* Take the IO mutex */
+ mutex_lock(&ctlr->io_mutex);
+
+ /* Lock queue */
+ spin_lock_irqsave(&ctlr->queue_lock, flags);
+
+ /* Make sure we are not already running a message */
+ if (ctlr->cur_msg)
+ goto out_unlock;
+
+ /* Check if the queue is idle */
+ if (list_empty(&ctlr->queue) || !ctlr->running) {
+ if (!ctlr->busy)
+ goto out_unlock;
+
+ /* Defer any non-atomic teardown to the thread */
+ if (!in_kthread) {
+ if (!ctlr->dummy_rx && !ctlr->dummy_tx &&
+ !ctlr->unprepare_transfer_hardware) {
+ spi_idle_runtime_pm(ctlr);
+ ctlr->busy = false;
+ ctlr->queue_empty = true;
+ trace_spi_controller_idle(ctlr);
+ } else {
+ kthread_queue_work(ctlr->kworker,
+ &ctlr->pump_messages);
+ }
+ goto out_unlock;
+ }
+
+ ctlr->busy = false;
+ spin_unlock_irqrestore(&ctlr->queue_lock, flags);
+
+ kfree(ctlr->dummy_rx);
+ ctlr->dummy_rx = NULL;
+ kfree(ctlr->dummy_tx);
+ ctlr->dummy_tx = NULL;
+ if (ctlr->unprepare_transfer_hardware &&
+ ctlr->unprepare_transfer_hardware(ctlr))
+ dev_err(&ctlr->dev,
+ "failed to unprepare transfer hardware\n");
+ spi_idle_runtime_pm(ctlr);
+ trace_spi_controller_idle(ctlr);
+
+ spin_lock_irqsave(&ctlr->queue_lock, flags);
+ ctlr->queue_empty = true;
+ goto out_unlock;
+ }
+
+ /* Extract head of queue */
+ msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
+ ctlr->cur_msg = msg;
+
+ list_del_init(&msg->queue);
+ if (ctlr->busy)
+ was_busy = true;
+ else
+ ctlr->busy = true;
+ spin_unlock_irqrestore(&ctlr->queue_lock, flags);
+
+ ret = __spi_pump_transfer_message(ctlr, msg, was_busy);
+ kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
+
+ ctlr->cur_msg = NULL;
+ ctlr->fallback = false;
+
+ mutex_unlock(&ctlr->io_mutex);
+
+ /* Prod the scheduler in case transfer_one() was busy waiting */
+ if (!ret)
+ cond_resched();
+ return;
+
+out_unlock:
+ spin_unlock_irqrestore(&ctlr->queue_lock, flags);
+ mutex_unlock(&ctlr->io_mutex);
+}
+
+/**
+ * spi_pump_messages - kthread work function which processes spi message queue
+ * @work: pointer to kthread work struct contained in the controller struct
+ */
+static void spi_pump_messages(struct kthread_work *work)
+{
+ struct spi_controller *ctlr =
+ container_of(work, struct spi_controller, pump_messages);
+
+ __spi_pump_messages(ctlr, true);
+}
+
+/**
+ * spi_take_timestamp_pre - helper to collect the beginning of the TX timestamp
+ * @ctlr: Pointer to the spi_controller structure of the driver
+ * @xfer: Pointer to the transfer being timestamped
+ * @progress: How many words (not bytes) have been transferred so far
+ * @irqs_off: If true, will disable IRQs and preemption for the duration of the
+ * transfer, for less jitter in time measurement. Only compatible
+ * with PIO drivers. If true, must follow up with
+ * spi_take_timestamp_post or otherwise system will crash.
+ * WARNING: for fully predictable results, the CPU frequency must
+ * also be under control (governor).
+ *
+ * This is a helper for drivers to collect the beginning of the TX timestamp
+ * for the requested byte from the SPI transfer. The frequency with which this
+ * function must be called (once per word, once for the whole transfer, once
+ * per batch of words etc) is arbitrary as long as the @tx buffer offset is
+ * greater than or equal to the requested byte at the time of the call. The
+ * timestamp is only taken once, at the first such call. It is assumed that
+ * the driver advances its @tx buffer pointer monotonically.
+ */
+void spi_take_timestamp_pre(struct spi_controller *ctlr,
+ struct spi_transfer *xfer,
+ size_t progress, bool irqs_off)
+{
+ if (!xfer->ptp_sts)
+ return;
+
+ if (xfer->timestamped)
+ return;
+
+ if (progress > xfer->ptp_sts_word_pre)
+ return;
+
+ /* Capture the resolution of the timestamp */
+ xfer->ptp_sts_word_pre = progress;
+
+ if (irqs_off) {
+ local_irq_save(ctlr->irq_flags);
+ preempt_disable();
+ }
+
+ ptp_read_system_prets(xfer->ptp_sts);
+}
+EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
+
+/**
+ * spi_take_timestamp_post - helper to collect the end of the TX timestamp
+ * @ctlr: Pointer to the spi_controller structure of the driver
+ * @xfer: Pointer to the transfer being timestamped
+ * @progress: How many words (not bytes) have been transferred so far
+ * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
+ *
+ * This is a helper for drivers to collect the end of the TX timestamp for
+ * the requested byte from the SPI transfer. Can be called with an arbitrary
+ * frequency: only the first call where @tx exceeds or is equal to the
+ * requested word will be timestamped.
+ */
+void spi_take_timestamp_post(struct spi_controller *ctlr,
+ struct spi_transfer *xfer,
+ size_t progress, bool irqs_off)
+{
+ if (!xfer->ptp_sts)
+ return;
+
+ if (xfer->timestamped)
+ return;
+
+ if (progress < xfer->ptp_sts_word_post)
+ return;
+
+ ptp_read_system_postts(xfer->ptp_sts);
+
+ if (irqs_off) {
+ local_irq_restore(ctlr->irq_flags);
+ preempt_enable();
+ }
+
+ /* Capture the resolution of the timestamp */
+ xfer->ptp_sts_word_post = progress;
+
+ xfer->timestamped = true;
+}
+EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
+
+/**
+ * spi_set_thread_rt - set the controller to pump at realtime priority
+ * @ctlr: controller to boost priority of
+ *
+ * This can be called because the controller requested realtime priority
+ * (by setting the ->rt value before calling spi_register_controller()) or
+ * because a device on the bus said that its transfers needed realtime
+ * priority.
+ *
+ * NOTE: at the moment if any device on a bus says it needs realtime then
+ * the thread will be at realtime priority for all transfers on that
+ * controller. If this eventually becomes a problem we may see if we can
+ * find a way to boost the priority only temporarily during relevant
+ * transfers.
+ */
+static void spi_set_thread_rt(struct spi_controller *ctlr)
+{
+ dev_info(&ctlr->dev,
+ "will run message pump with realtime priority\n");
+ sched_set_fifo(ctlr->kworker->task);
+}
+
+static int spi_init_queue(struct spi_controller *ctlr)
+{
+ ctlr->running = false;
+ ctlr->busy = false;
+ ctlr->queue_empty = true;
+
+ ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
+ if (IS_ERR(ctlr->kworker)) {
+ dev_err(&ctlr->dev, "failed to create message pump kworker\n");
+ return PTR_ERR(ctlr->kworker);
+ }
+
+ kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
+
+ /*
+ * Controller config will indicate if this controller should run the
+ * message pump with high (realtime) priority to reduce the transfer
+ * latency on the bus by minimising the delay between a transfer
+ * request and the scheduling of the message pump thread. Without this
+ * setting the message pump thread will remain at default priority.
+ */
+ if (ctlr->rt)
+ spi_set_thread_rt(ctlr);
+
+ return 0;
+}
+
+/**
+ * spi_get_next_queued_message() - called by driver to check for queued
+ * messages
+ * @ctlr: the controller to check for queued messages
+ *
+ * If there are more messages in the queue, the next message is returned from
+ * this call.
+ *
+ * Return: the next message in the queue, else NULL if the queue is empty.
+ */
+struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
+{
+ struct spi_message *next;
+ unsigned long flags;
+
+ /* Get a pointer to the next message, if any */
+ spin_lock_irqsave(&ctlr->queue_lock, flags);
+ next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
+ queue);
+ spin_unlock_irqrestore(&ctlr->queue_lock, flags);
+
+ return next;
+}
+EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
+
+/**
+ * spi_finalize_current_message() - the current message is complete
+ * @ctlr: the controller to return the message to
+ *
+ * Called by the driver to notify the core that the message in the front of the
+ * queue is complete and can be removed from the queue.
+ */
+void spi_finalize_current_message(struct spi_controller *ctlr)
+{
+ struct spi_transfer *xfer;
+ struct spi_message *mesg;
+ int ret;
+
+ mesg = ctlr->cur_msg;
+
+ if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
+ list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
+ ptp_read_system_postts(xfer->ptp_sts);
+ xfer->ptp_sts_word_post = xfer->len;
+ }
+ }
+
+ if (unlikely(ctlr->ptp_sts_supported))
+ list_for_each_entry(xfer, &mesg->transfers, transfer_list)
+ WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
+
+ spi_unmap_msg(ctlr, mesg);
+
+ /*
+ * In the prepare_messages callback the SPI bus has the opportunity
+ * to split a transfer to smaller chunks.
+ *
+ * Release the split transfers here since spi_map_msg() is done on
+ * the split transfers.
+ */
+ spi_res_release(ctlr, mesg);
+
+ if (mesg->prepared && ctlr->unprepare_message) {
+ ret = ctlr->unprepare_message(ctlr, mesg);
+ if (ret) {
+ dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
+ ret);
+ }
+ }
+
+ mesg->prepared = false;
+
+ WRITE_ONCE(ctlr->cur_msg_incomplete, false);
+ smp_mb(); /* See __spi_pump_transfer_message()... */
+ if (READ_ONCE(ctlr->cur_msg_need_completion))
+ complete(&ctlr->cur_msg_completion);
+
+ trace_spi_message_done(mesg);
+
+ mesg->state = NULL;
+ if (mesg->complete)
+ mesg->complete(mesg->context);
+}
+EXPORT_SYMBOL_GPL(spi_finalize_current_message);
+
+static int spi_start_queue(struct spi_controller *ctlr)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&ctlr->queue_lock, flags);
+
+ if (ctlr->running || ctlr->busy) {
+ spin_unlock_irqrestore(&ctlr->queue_lock, flags);
+ return -EBUSY;
+ }
+
+ ctlr->running = true;
+ ctlr->cur_msg = NULL;
+ spin_unlock_irqrestore(&ctlr->queue_lock, flags);
+
+ kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
+
+ return 0;
+}
+
+static int spi_stop_queue(struct spi_controller *ctlr)
+{
+ unsigned long flags;
+ unsigned limit = 500;
+ int ret = 0;
+
+ spin_lock_irqsave(&ctlr->queue_lock, flags);
+
+ /*
+ * This is a bit lame, but is optimized for the common execution path.
+ * A wait_queue on the ctlr->busy could be used, but then the common
+ * execution path (pump_messages) would be required to call wake_up or
+ * friends on every SPI message. Do this instead.
+ */
+ while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
+ spin_unlock_irqrestore(&ctlr->queue_lock, flags);
+ usleep_range(10000, 11000);
+ spin_lock_irqsave(&ctlr->queue_lock, flags);
+ }
+
+ if (!list_empty(&ctlr->queue) || ctlr->busy)
+ ret = -EBUSY;
+ else
+ ctlr->running = false;
+
+ spin_unlock_irqrestore(&ctlr->queue_lock, flags);
+
+ if (ret) {
+ dev_warn(&ctlr->dev, "could not stop message queue\n");
+ return ret;
+ }
+ return ret;
+}
+
+static int spi_destroy_queue(struct spi_controller *ctlr)
+{
+ int ret;
+
+ ret = spi_stop_queue(ctlr);
+
+ /*
+ * kthread_flush_worker will block until all work is done.
+ * If the reason that stop_queue timed out is that the work will never
+ * finish, then it does no good to call flush/stop thread, so
+ * return anyway.
+ */
+ if (ret) {
+ dev_err(&ctlr->dev, "problem destroying queue\n");
+ return ret;
+ }
+
+ kthread_destroy_worker(ctlr->kworker);
+
+ return 0;
+}
+
+static int __spi_queued_transfer(struct spi_device *spi,
+ struct spi_message *msg,
+ bool need_pump)
+{
+ struct spi_controller *ctlr = spi->controller;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ctlr->queue_lock, flags);
+
+ if (!ctlr->running) {
+ spin_unlock_irqrestore(&ctlr->queue_lock, flags);
+ return -ESHUTDOWN;
+ }
+ msg->actual_length = 0;
+ msg->status = -EINPROGRESS;
+
+ list_add_tail(&msg->queue, &ctlr->queue);
+ ctlr->queue_empty = false;
+ if (!ctlr->busy && need_pump)
+ kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
+
+ spin_unlock_irqrestore(&ctlr->queue_lock, flags);
+ return 0;
+}
+
+/**
+ * spi_queued_transfer - transfer function for queued transfers
+ * @spi: spi device which is requesting transfer
+ * @msg: spi message which is to handled is queued to driver queue
+ *
+ * Return: zero on success, else a negative error code.
+ */
+static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
+{
+ return __spi_queued_transfer(spi, msg, true);
+}
+
+static int spi_controller_initialize_queue(struct spi_controller *ctlr)
+{
+ int ret;
+
+ ctlr->transfer = spi_queued_transfer;
+ if (!ctlr->transfer_one_message)
+ ctlr->transfer_one_message = spi_transfer_one_message;
+
+ /* Initialize and start queue */
+ ret = spi_init_queue(ctlr);
+ if (ret) {
+ dev_err(&ctlr->dev, "problem initializing queue\n");
+ goto err_init_queue;
+ }
+ ctlr->queued = true;
+ ret = spi_start_queue(ctlr);
+ if (ret) {
+ dev_err(&ctlr->dev, "problem starting queue\n");
+ goto err_start_queue;
+ }
+
+ return 0;
+
+err_start_queue:
+ spi_destroy_queue(ctlr);
+err_init_queue:
+ return ret;
+}
+
+/**
+ * spi_flush_queue - Send all pending messages in the queue from the callers'
+ * context
+ * @ctlr: controller to process queue for
+ *
+ * This should be used when one wants to ensure all pending messages have been
+ * sent before doing something. Is used by the spi-mem code to make sure SPI
+ * memory operations do not preempt regular SPI transfers that have been queued
+ * before the spi-mem operation.
+ */
+void spi_flush_queue(struct spi_controller *ctlr)
+{
+ if (ctlr->transfer == spi_queued_transfer)
+ __spi_pump_messages(ctlr, false);
+}
+
+/*-------------------------------------------------------------------------*/
+
+#if defined(CONFIG_OF)
+static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
+ struct device_node *nc)
+{
+ u32 value;
+ int rc;
+
+ /* Mode (clock phase/polarity/etc.) */
+ if (of_property_read_bool(nc, "spi-cpha"))
+ spi->mode |= SPI_CPHA;
+ if (of_property_read_bool(nc, "spi-cpol"))
+ spi->mode |= SPI_CPOL;
+ if (of_property_read_bool(nc, "spi-3wire"))
+ spi->mode |= SPI_3WIRE;
+ if (of_property_read_bool(nc, "spi-lsb-first"))
+ spi->mode |= SPI_LSB_FIRST;
+ if (of_property_read_bool(nc, "spi-cs-high"))
+ spi->mode |= SPI_CS_HIGH;
+
+ /* Device DUAL/QUAD mode */
+ if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
+ switch (value) {
+ case 0:
+ spi->mode |= SPI_NO_TX;
+ break;
+ case 1:
+ break;
+ case 2:
+ spi->mode |= SPI_TX_DUAL;
+ break;
+ case 4:
+ spi->mode |= SPI_TX_QUAD;
+ break;
+ case 8:
+ spi->mode |= SPI_TX_OCTAL;
+ break;
+ default:
+ dev_warn(&ctlr->dev,
+ "spi-tx-bus-width %d not supported\n",
+ value);
+ break;
+ }
+ }
+
+ if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
+ switch (value) {
+ case 0:
+ spi->mode |= SPI_NO_RX;
+ break;
+ case 1:
+ break;
+ case 2:
+ spi->mode |= SPI_RX_DUAL;
+ break;
+ case 4:
+ spi->mode |= SPI_RX_QUAD;
+ break;
+ case 8:
+ spi->mode |= SPI_RX_OCTAL;
+ break;
+ default:
+ dev_warn(&ctlr->dev,
+ "spi-rx-bus-width %d not supported\n",
+ value);
+ break;
+ }
+ }
+
+ if (spi_controller_is_slave(ctlr)) {
+ if (!of_node_name_eq(nc, "slave")) {
+ dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
+ nc);
+ return -EINVAL;
+ }
+ return 0;
+ }
+
+ /* Device address */
+ rc = of_property_read_u32(nc, "reg", &value);
+ if (rc) {
+ dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
+ nc, rc);
+ return rc;
+ }
+ spi_set_chipselect(spi, 0, value);
+
+ /* Device speed */
+ if (!of_property_read_u32(nc, "spi-max-frequency", &value))
+ spi->max_speed_hz = value;
+
+ return 0;
+}
+
+static struct spi_device *
+of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
+{
+ struct spi_device *spi;
+ int rc;
+
+ /* Alloc an spi_device */
+ spi = spi_alloc_device(ctlr);
+ if (!spi) {
+ dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
+ rc = -ENOMEM;
+ goto err_out;
+ }
+
+ /* Select device driver */
+ rc = of_modalias_node(nc, spi->modalias,
+ sizeof(spi->modalias));
+ if (rc < 0) {
+ dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
+ goto err_out;
+ }
+
+ rc = of_spi_parse_dt(ctlr, spi, nc);
+ if (rc)
+ goto err_out;
+
+ /* Store a pointer to the node in the device structure */
+ of_node_get(nc);
+ spi->dev.of_node = nc;
+ spi->dev.fwnode = of_fwnode_handle(nc);
+
+ /* Register the new device */
+ rc = spi_add_device(spi);
+ if (rc) {
+ dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
+ goto err_of_node_put;
+ }
+
+ return spi;
+
+err_of_node_put:
+ of_node_put(nc);
+err_out:
+ spi_dev_put(spi);
+ return ERR_PTR(rc);
+}
+
+/**
+ * of_register_spi_devices() - Register child devices onto the SPI bus
+ * @ctlr: Pointer to spi_controller device
+ *
+ * Registers an spi_device for each child node of controller node which
+ * represents a valid SPI slave.
+ */
+static void of_register_spi_devices(struct spi_controller *ctlr)
+{
+ struct spi_device *spi;
+ struct device_node *nc;
+
+ if (!ctlr->dev.of_node)
+ return;
+
+ for_each_available_child_of_node(ctlr->dev.of_node, nc) {
+ if (of_node_test_and_set_flag(nc, OF_POPULATED))
+ continue;
+ spi = of_register_spi_device(ctlr, nc);
+ if (IS_ERR(spi)) {
+ dev_warn(&ctlr->dev,
+ "Failed to create SPI device for %pOF\n", nc);
+ of_node_clear_flag(nc, OF_POPULATED);
+ }
+ }
+}
+#else
+static void of_register_spi_devices(struct spi_controller *ctlr) { }
+#endif
+
+/**
+ * spi_new_ancillary_device() - Register ancillary SPI device
+ * @spi: Pointer to the main SPI device registering the ancillary device
+ * @chip_select: Chip Select of the ancillary device
+ *
+ * Register an ancillary SPI device; for example some chips have a chip-select
+ * for normal device usage and another one for setup/firmware upload.
+ *
+ * This may only be called from main SPI device's probe routine.
+ *
+ * Return: 0 on success; negative errno on failure
+ */
+struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
+ u8 chip_select)
+{
+ struct spi_device *ancillary;
+ int rc = 0;
+
+ /* Alloc an spi_device */
+ ancillary = spi_alloc_device(spi->controller);
+ if (!ancillary) {
+ rc = -ENOMEM;
+ goto err_out;
+ }
+
+ strscpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias));
+
+ /* Use provided chip-select for ancillary device */
+ spi_set_chipselect(ancillary, 0, chip_select);
+
+ /* Take over SPI mode/speed from SPI main device */
+ ancillary->max_speed_hz = spi->max_speed_hz;
+ ancillary->mode = spi->mode;
+
+ /* Register the new device */
+ rc = spi_add_device_locked(ancillary);
+ if (rc) {
+ dev_err(&spi->dev, "failed to register ancillary device\n");
+ goto err_out;
+ }
+
+ return ancillary;
+
+err_out:
+ spi_dev_put(ancillary);
+ return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_GPL(spi_new_ancillary_device);
+
+#ifdef CONFIG_ACPI
+struct acpi_spi_lookup {
+ struct spi_controller *ctlr;
+ u32 max_speed_hz;
+ u32 mode;
+ int irq;
+ u8 bits_per_word;
+ u8 chip_select;
+ int n;
+ int index;
+};
+
+static int acpi_spi_count(struct acpi_resource *ares, void *data)
+{
+ struct acpi_resource_spi_serialbus *sb;
+ int *count = data;
+
+ if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
+ return 1;
+
+ sb = &ares->data.spi_serial_bus;
+ if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_SPI)
+ return 1;
+
+ *count = *count + 1;
+
+ return 1;
+}
+
+/**
+ * acpi_spi_count_resources - Count the number of SpiSerialBus resources
+ * @adev: ACPI device
+ *
+ * Returns the number of SpiSerialBus resources in the ACPI-device's
+ * resource-list; or a negative error code.
+ */
+int acpi_spi_count_resources(struct acpi_device *adev)
+{
+ LIST_HEAD(r);
+ int count = 0;
+ int ret;
+
+ ret = acpi_dev_get_resources(adev, &r, acpi_spi_count, &count);
+ if (ret < 0)
+ return ret;
+
+ acpi_dev_free_resource_list(&r);
+
+ return count;
+}
+EXPORT_SYMBOL_GPL(acpi_spi_count_resources);
+
+static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
+ struct acpi_spi_lookup *lookup)
+{
+ const union acpi_object *obj;
+
+ if (!x86_apple_machine)
+ return;
+
+ if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
+ && obj->buffer.length >= 4)
+ lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
+
+ if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
+ && obj->buffer.length == 8)
+ lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
+
+ if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
+ && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
+ lookup->mode |= SPI_LSB_FIRST;
+
+ if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
+ && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
+ lookup->mode |= SPI_CPOL;
+
+ if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
+ && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
+ lookup->mode |= SPI_CPHA;
+}
+
+static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev);
+
+static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
+{
+ struct acpi_spi_lookup *lookup = data;
+ struct spi_controller *ctlr = lookup->ctlr;
+
+ if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
+ struct acpi_resource_spi_serialbus *sb;
+ acpi_handle parent_handle;
+ acpi_status status;
+
+ sb = &ares->data.spi_serial_bus;
+ if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
+
+ if (lookup->index != -1 && lookup->n++ != lookup->index)
+ return 1;
+
+ status = acpi_get_handle(NULL,
+ sb->resource_source.string_ptr,
+ &parent_handle);
+
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ if (ctlr) {
+ if (ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
+ return -ENODEV;
+ } else {
+ struct acpi_device *adev;
+
+ adev = acpi_fetch_acpi_dev(parent_handle);
+ if (!adev)
+ return -ENODEV;
+
+ ctlr = acpi_spi_find_controller_by_adev(adev);
+ if (!ctlr)
+ return -EPROBE_DEFER;
+
+ lookup->ctlr = ctlr;
+ }
+
+ /*
+ * ACPI DeviceSelection numbering is handled by the
+ * host controller driver in Windows and can vary
+ * from driver to driver. In Linux we always expect
+ * 0 .. max - 1 so we need to ask the driver to
+ * translate between the two schemes.
+ */
+ if (ctlr->fw_translate_cs) {
+ int cs = ctlr->fw_translate_cs(ctlr,
+ sb->device_selection);
+ if (cs < 0)
+ return cs;
+ lookup->chip_select = cs;
+ } else {
+ lookup->chip_select = sb->device_selection;
+ }
+
+ lookup->max_speed_hz = sb->connection_speed;
+ lookup->bits_per_word = sb->data_bit_length;
+
+ if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
+ lookup->mode |= SPI_CPHA;
+ if (sb->clock_polarity == ACPI_SPI_START_HIGH)
+ lookup->mode |= SPI_CPOL;
+ if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
+ lookup->mode |= SPI_CS_HIGH;
+ }
+ } else if (lookup->irq < 0) {
+ struct resource r;
+
+ if (acpi_dev_resource_interrupt(ares, 0, &r))
+ lookup->irq = r.start;
+ }
+
+ /* Always tell the ACPI core to skip this resource */
+ return 1;
+}
+
+/**
+ * acpi_spi_device_alloc - Allocate a spi device, and fill it in with ACPI information
+ * @ctlr: controller to which the spi device belongs
+ * @adev: ACPI Device for the spi device
+ * @index: Index of the spi resource inside the ACPI Node
+ *
+ * This should be used to allocate a new spi device from and ACPI Node.
+ * The caller is responsible for calling spi_add_device to register the spi device.
+ *
+ * If ctlr is set to NULL, the Controller for the spi device will be looked up
+ * using the resource.
+ * If index is set to -1, index is not used.
+ * Note: If index is -1, ctlr must be set.
+ *
+ * Return: a pointer to the new device, or ERR_PTR on error.
+ */
+struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
+ struct acpi_device *adev,
+ int index)
+{
+ acpi_handle parent_handle = NULL;
+ struct list_head resource_list;
+ struct acpi_spi_lookup lookup = {};
+ struct spi_device *spi;
+ int ret;
+
+ if (!ctlr && index == -1)
+ return ERR_PTR(-EINVAL);
+
+ lookup.ctlr = ctlr;
+ lookup.irq = -1;
+ lookup.index = index;
+ lookup.n = 0;
+
+ INIT_LIST_HEAD(&resource_list);
+ ret = acpi_dev_get_resources(adev, &resource_list,
+ acpi_spi_add_resource, &lookup);
+ acpi_dev_free_resource_list(&resource_list);
+
+ if (ret < 0)
+ /* Found SPI in _CRS but it points to another controller */
+ return ERR_PTR(ret);
+
+ if (!lookup.max_speed_hz &&
+ ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&
+ ACPI_HANDLE(lookup.ctlr->dev.parent) == parent_handle) {
+ /* Apple does not use _CRS but nested devices for SPI slaves */
+ acpi_spi_parse_apple_properties(adev, &lookup);
+ }
+
+ if (!lookup.max_speed_hz)
+ return ERR_PTR(-ENODEV);
+
+ spi = spi_alloc_device(lookup.ctlr);
+ if (!spi) {
+ dev_err(&lookup.ctlr->dev, "failed to allocate SPI device for %s\n",
+ dev_name(&adev->dev));
+ return ERR_PTR(-ENOMEM);
+ }
+
+ ACPI_COMPANION_SET(&spi->dev, adev);
+ spi->max_speed_hz = lookup.max_speed_hz;
+ spi->mode |= lookup.mode;
+ spi->irq = lookup.irq;
+ spi->bits_per_word = lookup.bits_per_word;
+ spi_set_chipselect(spi, 0, lookup.chip_select);
+
+ return spi;
+}
+EXPORT_SYMBOL_GPL(acpi_spi_device_alloc);
+
+static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
+ struct acpi_device *adev)
+{
+ struct spi_device *spi;
+
+ if (acpi_bus_get_status(adev) || !adev->status.present ||
+ acpi_device_enumerated(adev))
+ return AE_OK;
+
+ spi = acpi_spi_device_alloc(ctlr, adev, -1);
+ if (IS_ERR(spi)) {
+ if (PTR_ERR(spi) == -ENOMEM)
+ return AE_NO_MEMORY;
+ else
+ return AE_OK;
+ }
+
+ acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
+ sizeof(spi->modalias));
+
+ if (spi->irq < 0)
+ spi->irq = acpi_dev_gpio_irq_get(adev, 0);
+
+ acpi_device_set_enumerated(adev);
+
+ adev->power.flags.ignore_parent = true;
+ if (spi_add_device(spi)) {
+ adev->power.flags.ignore_parent = false;
+ dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
+ dev_name(&adev->dev));
+ spi_dev_put(spi);
+ }
+
+ return AE_OK;
+}
+
+static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
+ void *data, void **return_value)
+{
+ struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
+ struct spi_controller *ctlr = data;
+
+ if (!adev)
+ return AE_OK;
+
+ return acpi_register_spi_device(ctlr, adev);
+}
+
+#define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
+
+static void acpi_register_spi_devices(struct spi_controller *ctlr)
+{
+ acpi_status status;
+ acpi_handle handle;
+
+ handle = ACPI_HANDLE(ctlr->dev.parent);
+ if (!handle)
+ return;
+
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ SPI_ACPI_ENUMERATE_MAX_DEPTH,
+ acpi_spi_add_device, NULL, ctlr, NULL);
+ if (ACPI_FAILURE(status))
+ dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
+}
+#else
+static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
+#endif /* CONFIG_ACPI */
+
+static void spi_controller_release(struct device *dev)
+{
+ struct spi_controller *ctlr;
+
+ ctlr = container_of(dev, struct spi_controller, dev);
+ kfree(ctlr);
+}
+
+static struct class spi_master_class = {
+ .name = "spi_master",
+ .owner = THIS_MODULE,
+ .dev_release = spi_controller_release,
+ .dev_groups = spi_master_groups,
+};
+
+#ifdef CONFIG_SPI_SLAVE
+/**
+ * spi_slave_abort - abort the ongoing transfer request on an SPI slave
+ * controller
+ * @spi: device used for the current transfer
+ */
+int spi_slave_abort(struct spi_device *spi)
+{
+ struct spi_controller *ctlr = spi->controller;
+
+ if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
+ return ctlr->slave_abort(ctlr);
+
+ return -ENOTSUPP;
+}
+EXPORT_SYMBOL_GPL(spi_slave_abort);
+
+static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct spi_controller *ctlr = container_of(dev, struct spi_controller,
+ dev);
+ struct device *child;
+
+ child = device_find_any_child(&ctlr->dev);
+ return sprintf(buf, "%s\n",
+ child ? to_spi_device(child)->modalias : NULL);
+}
+
+static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct spi_controller *ctlr = container_of(dev, struct spi_controller,
+ dev);
+ struct spi_device *spi;
+ struct device *child;
+ char name[32];
+ int rc;
+
+ rc = sscanf(buf, "%31s", name);
+ if (rc != 1 || !name[0])
+ return -EINVAL;
+
+ child = device_find_any_child(&ctlr->dev);
+ if (child) {
+ /* Remove registered slave */
+ device_unregister(child);
+ put_device(child);
+ }
+
+ if (strcmp(name, "(null)")) {
+ /* Register new slave */
+ spi = spi_alloc_device(ctlr);
+ if (!spi)
+ return -ENOMEM;
+
+ strscpy(spi->modalias, name, sizeof(spi->modalias));
+
+ rc = spi_add_device(spi);
+ if (rc) {
+ spi_dev_put(spi);
+ return rc;
+ }
+ }
+
+ return count;
+}
+
+static DEVICE_ATTR_RW(slave);
+
+static struct attribute *spi_slave_attrs[] = {
+ &dev_attr_slave.attr,
+ NULL,
+};
+
+static const struct attribute_group spi_slave_group = {
+ .attrs = spi_slave_attrs,
+};
+
+static const struct attribute_group *spi_slave_groups[] = {
+ &spi_controller_statistics_group,
+ &spi_slave_group,
+ NULL,
+};
+
+static struct class spi_slave_class = {
+ .name = "spi_slave",
+ .owner = THIS_MODULE,
+ .dev_release = spi_controller_release,
+ .dev_groups = spi_slave_groups,
+};
+#else
+extern struct class spi_slave_class; /* dummy */
+#endif
+
+/**
+ * __spi_alloc_controller - allocate an SPI master or slave controller
+ * @dev: the controller, possibly using the platform_bus
+ * @size: how much zeroed driver-private data to allocate; the pointer to this
+ * memory is in the driver_data field of the returned device, accessible
+ * with spi_controller_get_devdata(); the memory is cacheline aligned;
+ * drivers granting DMA access to portions of their private data need to
+ * round up @size using ALIGN(size, dma_get_cache_alignment()).
+ * @slave: flag indicating whether to allocate an SPI master (false) or SPI
+ * slave (true) controller
+ * Context: can sleep
+ *
+ * This call is used only by SPI controller drivers, which are the
+ * only ones directly touching chip registers. It's how they allocate
+ * an spi_controller structure, prior to calling spi_register_controller().
+ *
+ * This must be called from context that can sleep.
+ *
+ * The caller is responsible for assigning the bus number and initializing the
+ * controller's methods before calling spi_register_controller(); and (after
+ * errors adding the device) calling spi_controller_put() to prevent a memory
+ * leak.
+ *
+ * Return: the SPI controller structure on success, else NULL.
+ */
+struct spi_controller *__spi_alloc_controller(struct device *dev,
+ unsigned int size, bool slave)
+{
+ struct spi_controller *ctlr;
+ size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
+
+ if (!dev)
+ return NULL;
+
+ ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
+ if (!ctlr)
+ return NULL;
+
+ device_initialize(&ctlr->dev);
+ INIT_LIST_HEAD(&ctlr->queue);
+ spin_lock_init(&ctlr->queue_lock);
+ spin_lock_init(&ctlr->bus_lock_spinlock);
+ mutex_init(&ctlr->bus_lock_mutex);
+ mutex_init(&ctlr->io_mutex);
+ mutex_init(&ctlr->add_lock);
+ ctlr->bus_num = -1;
+ ctlr->num_chipselect = 1;
+ ctlr->slave = slave;
+ if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
+ ctlr->dev.class = &spi_slave_class;
+ else
+ ctlr->dev.class = &spi_master_class;
+ ctlr->dev.parent = dev;
+ pm_suspend_ignore_children(&ctlr->dev, true);
+ spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
+
+ return ctlr;
+}
+EXPORT_SYMBOL_GPL(__spi_alloc_controller);
+
+static void devm_spi_release_controller(struct device *dev, void *ctlr)
+{
+ spi_controller_put(*(struct spi_controller **)ctlr);
+}
+
+/**
+ * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()
+ * @dev: physical device of SPI controller
+ * @size: how much zeroed driver-private data to allocate
+ * @slave: whether to allocate an SPI master (false) or SPI slave (true)
+ * Context: can sleep
+ *
+ * Allocate an SPI controller and automatically release a reference on it
+ * when @dev is unbound from its driver. Drivers are thus relieved from
+ * having to call spi_controller_put().
+ *
+ * The arguments to this function are identical to __spi_alloc_controller().
+ *
+ * Return: the SPI controller structure on success, else NULL.
+ */
+struct spi_controller *__devm_spi_alloc_controller(struct device *dev,
+ unsigned int size,
+ bool slave)
+{
+ struct spi_controller **ptr, *ctlr;
+
+ ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr),
+ GFP_KERNEL);
+ if (!ptr)
+ return NULL;
+
+ ctlr = __spi_alloc_controller(dev, size, slave);
+ if (ctlr) {
+ ctlr->devm_allocated = true;
+ *ptr = ctlr;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return ctlr;
+}
+EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller);
+
+/**
+ * spi_get_gpio_descs() - grab chip select GPIOs for the master
+ * @ctlr: The SPI master to grab GPIO descriptors for
+ */
+static int spi_get_gpio_descs(struct spi_controller *ctlr)
+{
+ int nb, i;
+ struct gpio_desc **cs;
+ struct device *dev = &ctlr->dev;
+ unsigned long native_cs_mask = 0;
+ unsigned int num_cs_gpios = 0;
+
+ nb = gpiod_count(dev, "cs");
+ if (nb < 0) {
+ /* No GPIOs at all is fine, else return the error */
+ if (nb == -ENOENT)
+ return 0;
+ return nb;
+ }
+
+ ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
+
+ cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
+ GFP_KERNEL);
+ if (!cs)
+ return -ENOMEM;
+ ctlr->cs_gpiods = cs;
+
+ for (i = 0; i < nb; i++) {
+ /*
+ * Most chipselects are active low, the inverted
+ * semantics are handled by special quirks in gpiolib,
+ * so initializing them GPIOD_OUT_LOW here means
+ * "unasserted", in most cases this will drive the physical
+ * line high.
+ */
+ cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
+ GPIOD_OUT_LOW);
+ if (IS_ERR(cs[i]))
+ return PTR_ERR(cs[i]);
+
+ if (cs[i]) {
+ /*
+ * If we find a CS GPIO, name it after the device and
+ * chip select line.
+ */
+ char *gpioname;
+
+ gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
+ dev_name(dev), i);
+ if (!gpioname)
+ return -ENOMEM;
+ gpiod_set_consumer_name(cs[i], gpioname);
+ num_cs_gpios++;
+ continue;
+ }
+
+ if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
+ dev_err(dev, "Invalid native chip select %d\n", i);
+ return -EINVAL;
+ }
+ native_cs_mask |= BIT(i);
+ }
+
+ ctlr->unused_native_cs = ffs(~native_cs_mask) - 1;
+
+ if ((ctlr->flags & SPI_MASTER_GPIO_SS) && num_cs_gpios &&
+ ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) {
+ dev_err(dev, "No unused native chip select available\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int spi_controller_check_ops(struct spi_controller *ctlr)
+{
+ /*
+ * The controller may implement only the high-level SPI-memory like
+ * operations if it does not support regular SPI transfers, and this is
+ * valid use case.
+ * If ->mem_ops is NULL, we request that at least one of the
+ * ->transfer_xxx() method be implemented.
+ */
+ if (ctlr->mem_ops) {
+ if (!ctlr->mem_ops->exec_op)
+ return -EINVAL;
+ } else if (!ctlr->transfer && !ctlr->transfer_one &&
+ !ctlr->transfer_one_message) {
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * spi_register_controller - register SPI master or slave controller
+ * @ctlr: initialized master, originally from spi_alloc_master() or
+ * spi_alloc_slave()
+ * Context: can sleep
+ *
+ * SPI controllers connect to their drivers using some non-SPI bus,
+ * such as the platform bus. The final stage of probe() in that code
+ * includes calling spi_register_controller() to hook up to this SPI bus glue.
+ *
+ * SPI controllers use board specific (often SOC specific) bus numbers,
+ * and board-specific addressing for SPI devices combines those numbers
+ * with chip select numbers. Since SPI does not directly support dynamic
+ * device identification, boards need configuration tables telling which
+ * chip is at which address.
+ *
+ * This must be called from context that can sleep. It returns zero on
+ * success, else a negative error code (dropping the controller's refcount).
+ * After a successful return, the caller is responsible for calling
+ * spi_unregister_controller().
+ *
+ * Return: zero on success, else a negative error code.
+ */
+int spi_register_controller(struct spi_controller *ctlr)
+{
+ struct device *dev = ctlr->dev.parent;
+ struct boardinfo *bi;
+ int status;
+ int id, first_dynamic;
+
+ if (!dev)
+ return -ENODEV;
+
+ /*
+ * Make sure all necessary hooks are implemented before registering
+ * the SPI controller.
+ */
+ status = spi_controller_check_ops(ctlr);
+ if (status)
+ return status;
+
+ if (ctlr->bus_num >= 0) {
+ /* Devices with a fixed bus num must check-in with the num */
+ mutex_lock(&board_lock);
+ id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
+ ctlr->bus_num + 1, GFP_KERNEL);
+ mutex_unlock(&board_lock);
+ if (WARN(id < 0, "couldn't get idr"))
+ return id == -ENOSPC ? -EBUSY : id;
+ ctlr->bus_num = id;
+ } else if (ctlr->dev.of_node) {
+ /* Allocate dynamic bus number using Linux idr */
+ id = of_alias_get_id(ctlr->dev.of_node, "spi");
+ if (id >= 0) {
+ ctlr->bus_num = id;
+ mutex_lock(&board_lock);
+ id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
+ ctlr->bus_num + 1, GFP_KERNEL);
+ mutex_unlock(&board_lock);
+ if (WARN(id < 0, "couldn't get idr"))
+ return id == -ENOSPC ? -EBUSY : id;
+ }
+ }
+ if (ctlr->bus_num < 0) {
+ first_dynamic = of_alias_get_highest_id("spi");
+ if (first_dynamic < 0)
+ first_dynamic = 0;
+ else
+ first_dynamic++;
+
+ mutex_lock(&board_lock);
+ id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
+ 0, GFP_KERNEL);
+ mutex_unlock(&board_lock);
+ if (WARN(id < 0, "couldn't get idr"))
+ return id;
+ ctlr->bus_num = id;
+ }
+ ctlr->bus_lock_flag = 0;
+ init_completion(&ctlr->xfer_completion);
+ init_completion(&ctlr->cur_msg_completion);
+ if (!ctlr->max_dma_len)
+ ctlr->max_dma_len = INT_MAX;
+
+ /*
+ * Register the device, then userspace will see it.
+ * Registration fails if the bus ID is in use.
+ */
+ dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
+
+ if (!spi_controller_is_slave(ctlr) && ctlr->use_gpio_descriptors) {
+ status = spi_get_gpio_descs(ctlr);
+ if (status)
+ goto free_bus_id;
+ /*
+ * A controller using GPIO descriptors always
+ * supports SPI_CS_HIGH if need be.
+ */
+ ctlr->mode_bits |= SPI_CS_HIGH;
+ }
+
+ /*
+ * Even if it's just one always-selected device, there must
+ * be at least one chipselect.
+ */
+ if (!ctlr->num_chipselect) {
+ status = -EINVAL;
+ goto free_bus_id;
+ }
+
+ /* Setting last_cs to -1 means no chip selected */
+ ctlr->last_cs = -1;
+
+ status = device_add(&ctlr->dev);
+ if (status < 0)
+ goto free_bus_id;
+ dev_dbg(dev, "registered %s %s\n",
+ spi_controller_is_slave(ctlr) ? "slave" : "master",
+ dev_name(&ctlr->dev));
+
+ /*
+ * If we're using a queued driver, start the queue. Note that we don't
+ * need the queueing logic if the driver is only supporting high-level
+ * memory operations.
+ */
+ if (ctlr->transfer) {
+ dev_info(dev, "controller is unqueued, this is deprecated\n");
+ } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
+ status = spi_controller_initialize_queue(ctlr);
+ if (status) {
+ device_del(&ctlr->dev);
+ goto free_bus_id;
+ }
+ }
+ /* Add statistics */
+ ctlr->pcpu_statistics = spi_alloc_pcpu_stats(dev);
+ if (!ctlr->pcpu_statistics) {
+ dev_err(dev, "Error allocating per-cpu statistics\n");
+ status = -ENOMEM;
+ goto destroy_queue;
+ }
+
+ mutex_lock(&board_lock);
+ list_add_tail(&ctlr->list, &spi_controller_list);
+ list_for_each_entry(bi, &board_list, list)
+ spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
+ mutex_unlock(&board_lock);
+
+ /* Register devices from the device tree and ACPI */
+ of_register_spi_devices(ctlr);
+ acpi_register_spi_devices(ctlr);
+ return status;
+
+destroy_queue:
+ spi_destroy_queue(ctlr);
+free_bus_id:
+ mutex_lock(&board_lock);
+ idr_remove(&spi_master_idr, ctlr->bus_num);
+ mutex_unlock(&board_lock);
+ return status;
+}
+EXPORT_SYMBOL_GPL(spi_register_controller);
+
+static void devm_spi_unregister(struct device *dev, void *res)
+{
+ spi_unregister_controller(*(struct spi_controller **)res);
+}
+
+/**
+ * devm_spi_register_controller - register managed SPI master or slave
+ * controller
+ * @dev: device managing SPI controller
+ * @ctlr: initialized controller, originally from spi_alloc_master() or
+ * spi_alloc_slave()
+ * Context: can sleep
+ *
+ * Register a SPI device as with spi_register_controller() which will
+ * automatically be unregistered and freed.
+ *
+ * Return: zero on success, else a negative error code.
+ */
+int devm_spi_register_controller(struct device *dev,
+ struct spi_controller *ctlr)
+{
+ struct spi_controller **ptr;
+ int ret;
+
+ ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return -ENOMEM;
+
+ ret = spi_register_controller(ctlr);
+ if (!ret) {
+ *ptr = ctlr;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(devm_spi_register_controller);
+
+static int __unregister(struct device *dev, void *null)
+{
+ spi_unregister_device(to_spi_device(dev));
+ return 0;
+}
+
+/**
+ * spi_unregister_controller - unregister SPI master or slave controller
+ * @ctlr: the controller being unregistered
+ * Context: can sleep
+ *
+ * This call is used only by SPI controller drivers, which are the
+ * only ones directly touching chip registers.
+ *
+ * This must be called from context that can sleep.
+ *
+ * Note that this function also drops a reference to the controller.
+ */
+void spi_unregister_controller(struct spi_controller *ctlr)
+{
+ struct spi_controller *found;
+ int id = ctlr->bus_num;
+
+ /* Prevent addition of new devices, unregister existing ones */
+ if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
+ mutex_lock(&ctlr->add_lock);
+
+ device_for_each_child(&ctlr->dev, NULL, __unregister);
+
+ /* First make sure that this controller was ever added */
+ mutex_lock(&board_lock);
+ found = idr_find(&spi_master_idr, id);
+ mutex_unlock(&board_lock);
+ if (ctlr->queued) {
+ if (spi_destroy_queue(ctlr))
+ dev_err(&ctlr->dev, "queue remove failed\n");
+ }
+ mutex_lock(&board_lock);
+ list_del(&ctlr->list);
+ mutex_unlock(&board_lock);
+
+ device_del(&ctlr->dev);
+
+ /* Free bus id */
+ mutex_lock(&board_lock);
+ if (found == ctlr)
+ idr_remove(&spi_master_idr, id);
+ mutex_unlock(&board_lock);
+
+ if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
+ mutex_unlock(&ctlr->add_lock);
+
+ /* Release the last reference on the controller if its driver
+ * has not yet been converted to devm_spi_alloc_master/slave().
+ */
+ if (!ctlr->devm_allocated)
+ put_device(&ctlr->dev);
+}
+EXPORT_SYMBOL_GPL(spi_unregister_controller);
+
+static inline int __spi_check_suspended(const struct spi_controller *ctlr)
+{
+ return ctlr->flags & SPI_CONTROLLER_SUSPENDED ? -ESHUTDOWN : 0;
+}
+
+static inline void __spi_mark_suspended(struct spi_controller *ctlr)
+{
+ mutex_lock(&ctlr->bus_lock_mutex);
+ ctlr->flags |= SPI_CONTROLLER_SUSPENDED;
+ mutex_unlock(&ctlr->bus_lock_mutex);
+}
+
+static inline void __spi_mark_resumed(struct spi_controller *ctlr)
+{
+ mutex_lock(&ctlr->bus_lock_mutex);
+ ctlr->flags &= ~SPI_CONTROLLER_SUSPENDED;
+ mutex_unlock(&ctlr->bus_lock_mutex);
+}
+
+int spi_controller_suspend(struct spi_controller *ctlr)
+{
+ int ret = 0;
+
+ /* Basically no-ops for non-queued controllers */
+ if (ctlr->queued) {
+ ret = spi_stop_queue(ctlr);
+ if (ret)
+ dev_err(&ctlr->dev, "queue stop failed\n");
+ }
+
+ __spi_mark_suspended(ctlr);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(spi_controller_suspend);
+
+int spi_controller_resume(struct spi_controller *ctlr)
+{
+ int ret = 0;
+
+ __spi_mark_resumed(ctlr);
+
+ if (ctlr->queued) {
+ ret = spi_start_queue(ctlr);
+ if (ret)
+ dev_err(&ctlr->dev, "queue restart failed\n");
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(spi_controller_resume);
+
+/*-------------------------------------------------------------------------*/
+
+/* Core methods for spi_message alterations */
+
+static void __spi_replace_transfers_release(struct spi_controller *ctlr,
+ struct spi_message *msg,
+ void *res)
+{
+ struct spi_replaced_transfers *rxfer = res;
+ size_t i;
+
+ /* Call extra callback if requested */
+ if (rxfer->release)
+ rxfer->release(ctlr, msg, res);
+
+ /* Insert replaced transfers back into the message */
+ list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
+
+ /* Remove the formerly inserted entries */
+ for (i = 0; i < rxfer->inserted; i++)
+ list_del(&rxfer->inserted_transfers[i].transfer_list);
+}
+
+/**
+ * spi_replace_transfers - replace transfers with several transfers
+ * and register change with spi_message.resources
+ * @msg: the spi_message we work upon
+ * @xfer_first: the first spi_transfer we want to replace
+ * @remove: number of transfers to remove
+ * @insert: the number of transfers we want to insert instead
+ * @release: extra release code necessary in some circumstances
+ * @extradatasize: extra data to allocate (with alignment guarantees
+ * of struct @spi_transfer)
+ * @gfp: gfp flags
+ *
+ * Returns: pointer to @spi_replaced_transfers,
+ * PTR_ERR(...) in case of errors.
+ */
+static struct spi_replaced_transfers *spi_replace_transfers(
+ struct spi_message *msg,
+ struct spi_transfer *xfer_first,
+ size_t remove,
+ size_t insert,
+ spi_replaced_release_t release,
+ size_t extradatasize,
+ gfp_t gfp)
+{
+ struct spi_replaced_transfers *rxfer;
+ struct spi_transfer *xfer;
+ size_t i;
+
+ /* Allocate the structure using spi_res */
+ rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
+ struct_size(rxfer, inserted_transfers, insert)
+ + extradatasize,
+ gfp);
+ if (!rxfer)
+ return ERR_PTR(-ENOMEM);
+
+ /* The release code to invoke before running the generic release */
+ rxfer->release = release;
+
+ /* Assign extradata */
+ if (extradatasize)
+ rxfer->extradata =
+ &rxfer->inserted_transfers[insert];
+
+ /* Init the replaced_transfers list */
+ INIT_LIST_HEAD(&rxfer->replaced_transfers);
+
+ /*
+ * Assign the list_entry after which we should reinsert
+ * the @replaced_transfers - it may be spi_message.messages!
+ */
+ rxfer->replaced_after = xfer_first->transfer_list.prev;
+
+ /* Remove the requested number of transfers */
+ for (i = 0; i < remove; i++) {
+ /*
+ * If the entry after replaced_after it is msg->transfers
+ * then we have been requested to remove more transfers
+ * than are in the list.
+ */
+ if (rxfer->replaced_after->next == &msg->transfers) {
+ dev_err(&msg->spi->dev,
+ "requested to remove more spi_transfers than are available\n");
+ /* Insert replaced transfers back into the message */
+ list_splice(&rxfer->replaced_transfers,
+ rxfer->replaced_after);
+
+ /* Free the spi_replace_transfer structure... */
+ spi_res_free(rxfer);
+
+ /* ...and return with an error */
+ return ERR_PTR(-EINVAL);
+ }
+
+ /*
+ * Remove the entry after replaced_after from list of
+ * transfers and add it to list of replaced_transfers.
+ */
+ list_move_tail(rxfer->replaced_after->next,
+ &rxfer->replaced_transfers);
+ }
+
+ /*
+ * Create copy of the given xfer with identical settings
+ * based on the first transfer to get removed.
+ */
+ for (i = 0; i < insert; i++) {
+ /* We need to run in reverse order */
+ xfer = &rxfer->inserted_transfers[insert - 1 - i];
+
+ /* Copy all spi_transfer data */
+ memcpy(xfer, xfer_first, sizeof(*xfer));
+
+ /* Add to list */
+ list_add(&xfer->transfer_list, rxfer->replaced_after);
+
+ /* Clear cs_change and delay for all but the last */
+ if (i) {
+ xfer->cs_change = false;
+ xfer->delay.value = 0;
+ }
+ }
+
+ /* Set up inserted... */
+ rxfer->inserted = insert;
+
+ /* ...and register it with spi_res/spi_message */
+ spi_res_add(msg, rxfer);
+
+ return rxfer;
+}
+
+static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
+ struct spi_message *msg,
+ struct spi_transfer **xferp,
+ size_t maxsize,
+ gfp_t gfp)
+{
+ struct spi_transfer *xfer = *xferp, *xfers;
+ struct spi_replaced_transfers *srt;
+ size_t offset;
+ size_t count, i;
+
+ /* Calculate how many we have to replace */
+ count = DIV_ROUND_UP(xfer->len, maxsize);
+
+ /* Create replacement */
+ srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
+ if (IS_ERR(srt))
+ return PTR_ERR(srt);
+ xfers = srt->inserted_transfers;
+
+ /*
+ * Now handle each of those newly inserted spi_transfers.
+ * Note that the replacements spi_transfers all are preset
+ * to the same values as *xferp, so tx_buf, rx_buf and len
+ * are all identical (as well as most others)
+ * so we just have to fix up len and the pointers.
+ *
+ * This also includes support for the depreciated
+ * spi_message.is_dma_mapped interface.
+ */
+
+ /*
+ * The first transfer just needs the length modified, so we
+ * run it outside the loop.
+ */
+ xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
+
+ /* All the others need rx_buf/tx_buf also set */
+ for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
+ /* Update rx_buf, tx_buf and dma */
+ if (xfers[i].rx_buf)
+ xfers[i].rx_buf += offset;
+ if (xfers[i].rx_dma)
+ xfers[i].rx_dma += offset;
+ if (xfers[i].tx_buf)
+ xfers[i].tx_buf += offset;
+ if (xfers[i].tx_dma)
+ xfers[i].tx_dma += offset;
+
+ /* Update length */
+ xfers[i].len = min(maxsize, xfers[i].len - offset);
+ }
+
+ /*
+ * We set up xferp to the last entry we have inserted,
+ * so that we skip those already split transfers.
+ */
+ *xferp = &xfers[count - 1];
+
+ /* Increment statistics counters */
+ SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics,
+ transfers_split_maxsize);
+ SPI_STATISTICS_INCREMENT_FIELD(msg->spi->pcpu_statistics,
+ transfers_split_maxsize);
+
+ return 0;
+}
+
+/**
+ * spi_split_transfers_maxsize - split spi transfers into multiple transfers
+ * when an individual transfer exceeds a
+ * certain size
+ * @ctlr: the @spi_controller for this transfer
+ * @msg: the @spi_message to transform
+ * @maxsize: the maximum when to apply this
+ * @gfp: GFP allocation flags
+ *
+ * Return: status of transformation
+ */
+int spi_split_transfers_maxsize(struct spi_controller *ctlr,
+ struct spi_message *msg,
+ size_t maxsize,
+ gfp_t gfp)
+{
+ struct spi_transfer *xfer;
+ int ret;
+
+ /*
+ * Iterate over the transfer_list,
+ * but note that xfer is advanced to the last transfer inserted
+ * to avoid checking sizes again unnecessarily (also xfer does
+ * potentially belong to a different list by the time the
+ * replacement has happened).
+ */
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ if (xfer->len > maxsize) {
+ ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
+ maxsize, gfp);
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
+
+/*-------------------------------------------------------------------------*/
+
+/* Core methods for SPI controller protocol drivers. Some of the
+ * other core methods are currently defined as inline functions.
+ */
+
+static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
+ u8 bits_per_word)
+{
+ if (ctlr->bits_per_word_mask) {
+ /* Only 32 bits fit in the mask */
+ if (bits_per_word > 32)
+ return -EINVAL;
+ if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * spi_set_cs_timing - configure CS setup, hold, and inactive delays
+ * @spi: the device that requires specific CS timing configuration
+ *
+ * Return: zero on success, else a negative error code.
+ */
+static int spi_set_cs_timing(struct spi_device *spi)
+{
+ struct device *parent = spi->controller->dev.parent;
+ int status = 0;
+
+ if (spi->controller->set_cs_timing && !spi_get_csgpiod(spi, 0)) {
+ if (spi->controller->auto_runtime_pm) {
+ status = pm_runtime_get_sync(parent);
+ if (status < 0) {
+ pm_runtime_put_noidle(parent);
+ dev_err(&spi->controller->dev, "Failed to power device: %d\n",
+ status);
+ return status;
+ }
+
+ status = spi->controller->set_cs_timing(spi);
+ pm_runtime_mark_last_busy(parent);
+ pm_runtime_put_autosuspend(parent);
+ } else {
+ status = spi->controller->set_cs_timing(spi);
+ }
+ }
+ return status;
+}
+
+/**
+ * spi_setup - setup SPI mode and clock rate
+ * @spi: the device whose settings are being modified
+ * Context: can sleep, and no requests are queued to the device
+ *
+ * SPI protocol drivers may need to update the transfer mode if the
+ * device doesn't work with its default. They may likewise need
+ * to update clock rates or word sizes from initial values. This function
+ * changes those settings, and must be called from a context that can sleep.
+ * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
+ * effect the next time the device is selected and data is transferred to
+ * or from it. When this function returns, the spi device is deselected.
+ *
+ * Note that this call will fail if the protocol driver specifies an option
+ * that the underlying controller or its driver does not support. For
+ * example, not all hardware supports wire transfers using nine bit words,
+ * LSB-first wire encoding, or active-high chipselects.
+ *
+ * Return: zero on success, else a negative error code.
+ */
+int spi_setup(struct spi_device *spi)
+{
+ unsigned bad_bits, ugly_bits;
+ int status = 0;
+
+ /*
+ * Check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
+ * are set at the same time.
+ */
+ if ((hweight_long(spi->mode &
+ (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||
+ (hweight_long(spi->mode &
+ (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) {
+ dev_err(&spi->dev,
+ "setup: can not select any two of dual, quad and no-rx/tx at the same time\n");
+ return -EINVAL;
+ }
+ /* If it is SPI_3WIRE mode, DUAL and QUAD should be forbidden */
+ if ((spi->mode & SPI_3WIRE) && (spi->mode &
+ (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
+ SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
+ return -EINVAL;
+ /*
+ * Help drivers fail *cleanly* when they need options
+ * that aren't supported with their current controller.
+ * SPI_CS_WORD has a fallback software implementation,
+ * so it is ignored here.
+ */
+ bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD |
+ SPI_NO_TX | SPI_NO_RX);
+ ugly_bits = bad_bits &
+ (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
+ SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
+ if (ugly_bits) {
+ dev_warn(&spi->dev,
+ "setup: ignoring unsupported mode bits %x\n",
+ ugly_bits);
+ spi->mode &= ~ugly_bits;
+ bad_bits &= ~ugly_bits;
+ }
+ if (bad_bits) {
+ dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
+ bad_bits);
+ return -EINVAL;
+ }
+
+ if (!spi->bits_per_word) {
+ spi->bits_per_word = 8;
+ } else {
+ /*
+ * Some controllers may not support the default 8 bits-per-word
+ * so only perform the check when this is explicitly provided.
+ */
+ status = __spi_validate_bits_per_word(spi->controller,
+ spi->bits_per_word);
+ if (status)
+ return status;
+ }
+
+ if (spi->controller->max_speed_hz &&
+ (!spi->max_speed_hz ||
+ spi->max_speed_hz > spi->controller->max_speed_hz))
+ spi->max_speed_hz = spi->controller->max_speed_hz;
+
+ mutex_lock(&spi->controller->io_mutex);
+
+ if (spi->controller->setup) {
+ status = spi->controller->setup(spi);
+ if (status) {
+ mutex_unlock(&spi->controller->io_mutex);
+ dev_err(&spi->controller->dev, "Failed to setup device: %d\n",
+ status);
+ return status;
+ }
+ }
+
+ status = spi_set_cs_timing(spi);
+ if (status) {
+ mutex_unlock(&spi->controller->io_mutex);
+ return status;
+ }
+
+ if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
+ status = pm_runtime_resume_and_get(spi->controller->dev.parent);
+ if (status < 0) {
+ mutex_unlock(&spi->controller->io_mutex);
+ dev_err(&spi->controller->dev, "Failed to power device: %d\n",
+ status);
+ return status;
+ }
+
+ /*
+ * We do not want to return positive value from pm_runtime_get,
+ * there are many instances of devices calling spi_setup() and
+ * checking for a non-zero return value instead of a negative
+ * return value.
+ */
+ status = 0;
+
+ spi_set_cs(spi, false, true);
+ pm_runtime_mark_last_busy(spi->controller->dev.parent);
+ pm_runtime_put_autosuspend(spi->controller->dev.parent);
+ } else {
+ spi_set_cs(spi, false, true);
+ }
+
+ mutex_unlock(&spi->controller->io_mutex);
+
+ if (spi->rt && !spi->controller->rt) {
+ spi->controller->rt = true;
+ spi_set_thread_rt(spi->controller);
+ }
+
+ trace_spi_setup(spi, status);
+
+ dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
+ spi->mode & SPI_MODE_X_MASK,
+ (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
+ (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
+ (spi->mode & SPI_3WIRE) ? "3wire, " : "",
+ (spi->mode & SPI_LOOP) ? "loopback, " : "",
+ spi->bits_per_word, spi->max_speed_hz,
+ status);
+
+ return status;
+}
+EXPORT_SYMBOL_GPL(spi_setup);
+
+static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
+ struct spi_device *spi)
+{
+ int delay1, delay2;
+
+ delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
+ if (delay1 < 0)
+ return delay1;
+
+ delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
+ if (delay2 < 0)
+ return delay2;
+
+ if (delay1 < delay2)
+ memcpy(&xfer->word_delay, &spi->word_delay,
+ sizeof(xfer->word_delay));
+
+ return 0;
+}
+
+static int __spi_validate(struct spi_device *spi, struct spi_message *message)
+{
+ struct spi_controller *ctlr = spi->controller;
+ struct spi_transfer *xfer;
+ int w_size;
+
+ if (list_empty(&message->transfers))
+ return -EINVAL;
+
+ /*
+ * If an SPI controller does not support toggling the CS line on each
+ * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
+ * for the CS line, we can emulate the CS-per-word hardware function by
+ * splitting transfers into one-word transfers and ensuring that
+ * cs_change is set for each transfer.
+ */
+ if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
+ spi_get_csgpiod(spi, 0))) {
+ size_t maxsize;
+ int ret;
+
+ maxsize = (spi->bits_per_word + 7) / 8;
+
+ /* spi_split_transfers_maxsize() requires message->spi */
+ message->spi = spi;
+
+ ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
+ GFP_KERNEL);
+ if (ret)
+ return ret;
+
+ list_for_each_entry(xfer, &message->transfers, transfer_list) {
+ /* Don't change cs_change on the last entry in the list */
+ if (list_is_last(&xfer->transfer_list, &message->transfers))
+ break;
+ xfer->cs_change = 1;
+ }
+ }
+
+ /*
+ * Half-duplex links include original MicroWire, and ones with
+ * only one data pin like SPI_3WIRE (switches direction) or where
+ * either MOSI or MISO is missing. They can also be caused by
+ * software limitations.
+ */
+ if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
+ (spi->mode & SPI_3WIRE)) {
+ unsigned flags = ctlr->flags;
+
+ list_for_each_entry(xfer, &message->transfers, transfer_list) {
+ if (xfer->rx_buf && xfer->tx_buf)
+ return -EINVAL;
+ if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
+ return -EINVAL;
+ if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
+ return -EINVAL;
+ }
+ }
+
+ /*
+ * Set transfer bits_per_word and max speed as spi device default if
+ * it is not set for this transfer.
+ * Set transfer tx_nbits and rx_nbits as single transfer default
+ * (SPI_NBITS_SINGLE) if it is not set for this transfer.
+ * Ensure transfer word_delay is at least as long as that required by
+ * device itself.
+ */
+ message->frame_length = 0;
+ list_for_each_entry(xfer, &message->transfers, transfer_list) {
+ xfer->effective_speed_hz = 0;
+ message->frame_length += xfer->len;
+ if (!xfer->bits_per_word)
+ xfer->bits_per_word = spi->bits_per_word;
+
+ if (!xfer->speed_hz)
+ xfer->speed_hz = spi->max_speed_hz;
+
+ if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
+ xfer->speed_hz = ctlr->max_speed_hz;
+
+ if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
+ return -EINVAL;
+
+ /*
+ * SPI transfer length should be multiple of SPI word size
+ * where SPI word size should be power-of-two multiple.
+ */
+ if (xfer->bits_per_word <= 8)
+ w_size = 1;
+ else if (xfer->bits_per_word <= 16)
+ w_size = 2;
+ else
+ w_size = 4;
+
+ /* No partial transfers accepted */
+ if (xfer->len % w_size)
+ return -EINVAL;
+
+ if (xfer->speed_hz && ctlr->min_speed_hz &&
+ xfer->speed_hz < ctlr->min_speed_hz)
+ return -EINVAL;
+
+ if (xfer->tx_buf && !xfer->tx_nbits)
+ xfer->tx_nbits = SPI_NBITS_SINGLE;
+ if (xfer->rx_buf && !xfer->rx_nbits)
+ xfer->rx_nbits = SPI_NBITS_SINGLE;
+ /*
+ * Check transfer tx/rx_nbits:
+ * 1. check the value matches one of single, dual and quad
+ * 2. check tx/rx_nbits match the mode in spi_device
+ */
+ if (xfer->tx_buf) {
+ if (spi->mode & SPI_NO_TX)
+ return -EINVAL;
+ if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
+ xfer->tx_nbits != SPI_NBITS_DUAL &&
+ xfer->tx_nbits != SPI_NBITS_QUAD)
+ return -EINVAL;
+ if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
+ !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
+ return -EINVAL;
+ if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
+ !(spi->mode & SPI_TX_QUAD))
+ return -EINVAL;
+ }
+ /* Check transfer rx_nbits */
+ if (xfer->rx_buf) {
+ if (spi->mode & SPI_NO_RX)
+ return -EINVAL;
+ if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
+ xfer->rx_nbits != SPI_NBITS_DUAL &&
+ xfer->rx_nbits != SPI_NBITS_QUAD)
+ return -EINVAL;
+ if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
+ !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
+ return -EINVAL;
+ if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
+ !(spi->mode & SPI_RX_QUAD))
+ return -EINVAL;
+ }
+
+ if (_spi_xfer_word_delay_update(xfer, spi))
+ return -EINVAL;
+ }
+
+ message->status = -EINPROGRESS;
+
+ return 0;
+}
+
+static int __spi_async(struct spi_device *spi, struct spi_message *message)
+{
+ struct spi_controller *ctlr = spi->controller;
+ struct spi_transfer *xfer;
+
+ /*
+ * Some controllers do not support doing regular SPI transfers. Return
+ * ENOTSUPP when this is the case.
+ */
+ if (!ctlr->transfer)
+ return -ENOTSUPP;
+
+ message->spi = spi;
+
+ SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_async);
+ SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_async);
+
+ trace_spi_message_submit(message);
+
+ if (!ctlr->ptp_sts_supported) {
+ list_for_each_entry(xfer, &message->transfers, transfer_list) {
+ xfer->ptp_sts_word_pre = 0;
+ ptp_read_system_prets(xfer->ptp_sts);
+ }
+ }
+
+ return ctlr->transfer(spi, message);
+}
+
+/**
+ * spi_async - asynchronous SPI transfer
+ * @spi: device with which data will be exchanged
+ * @message: describes the data transfers, including completion callback
+ * Context: any (irqs may be blocked, etc)
+ *
+ * This call may be used in_irq and other contexts which can't sleep,
+ * as well as from task contexts which can sleep.
+ *
+ * The completion callback is invoked in a context which can't sleep.
+ * Before that invocation, the value of message->status is undefined.
+ * When the callback is issued, message->status holds either zero (to
+ * indicate complete success) or a negative error code. After that
+ * callback returns, the driver which issued the transfer request may
+ * deallocate the associated memory; it's no longer in use by any SPI
+ * core or controller driver code.
+ *
+ * Note that although all messages to a spi_device are handled in
+ * FIFO order, messages may go to different devices in other orders.
+ * Some device might be higher priority, or have various "hard" access
+ * time requirements, for example.
+ *
+ * On detection of any fault during the transfer, processing of
+ * the entire message is aborted, and the device is deselected.
+ * Until returning from the associated message completion callback,
+ * no other spi_message queued to that device will be processed.
+ * (This rule applies equally to all the synchronous transfer calls,
+ * which are wrappers around this core asynchronous primitive.)
+ *
+ * Return: zero on success, else a negative error code.
+ */
+int spi_async(struct spi_device *spi, struct spi_message *message)
+{
+ struct spi_controller *ctlr = spi->controller;
+ int ret;
+ unsigned long flags;
+
+ ret = __spi_validate(spi, message);
+ if (ret != 0)
+ return ret;
+
+ spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
+
+ if (ctlr->bus_lock_flag)
+ ret = -EBUSY;
+ else
+ ret = __spi_async(spi, message);
+
+ spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(spi_async);
+
+/**
+ * spi_async_locked - version of spi_async with exclusive bus usage
+ * @spi: device with which data will be exchanged
+ * @message: describes the data transfers, including completion callback
+ * Context: any (irqs may be blocked, etc)
+ *
+ * This call may be used in_irq and other contexts which can't sleep,
+ * as well as from task contexts which can sleep.
+ *
+ * The completion callback is invoked in a context which can't sleep.
+ * Before that invocation, the value of message->status is undefined.
+ * When the callback is issued, message->status holds either zero (to
+ * indicate complete success) or a negative error code. After that
+ * callback returns, the driver which issued the transfer request may
+ * deallocate the associated memory; it's no longer in use by any SPI
+ * core or controller driver code.
+ *
+ * Note that although all messages to a spi_device are handled in
+ * FIFO order, messages may go to different devices in other orders.
+ * Some device might be higher priority, or have various "hard" access
+ * time requirements, for example.
+ *
+ * On detection of any fault during the transfer, processing of
+ * the entire message is aborted, and the device is deselected.
+ * Until returning from the associated message completion callback,
+ * no other spi_message queued to that device will be processed.
+ * (This rule applies equally to all the synchronous transfer calls,
+ * which are wrappers around this core asynchronous primitive.)
+ *
+ * Return: zero on success, else a negative error code.
+ */
+static int spi_async_locked(struct spi_device *spi, struct spi_message *message)
+{
+ struct spi_controller *ctlr = spi->controller;
+ int ret;
+ unsigned long flags;
+
+ ret = __spi_validate(spi, message);
+ if (ret != 0)
+ return ret;
+
+ spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
+
+ ret = __spi_async(spi, message);
+
+ spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
+
+ return ret;
+
+}
+
+static void __spi_transfer_message_noqueue(struct spi_controller *ctlr, struct spi_message *msg)
+{
+ bool was_busy;
+ int ret;
+
+ mutex_lock(&ctlr->io_mutex);
+
+ was_busy = ctlr->busy;
+
+ ctlr->cur_msg = msg;
+ ret = __spi_pump_transfer_message(ctlr, msg, was_busy);
+ if (ret)
+ dev_err(&ctlr->dev, "noqueue transfer failed\n");
+ ctlr->cur_msg = NULL;
+ ctlr->fallback = false;
+
+ if (!was_busy) {
+ kfree(ctlr->dummy_rx);
+ ctlr->dummy_rx = NULL;
+ kfree(ctlr->dummy_tx);
+ ctlr->dummy_tx = NULL;
+ if (ctlr->unprepare_transfer_hardware &&
+ ctlr->unprepare_transfer_hardware(ctlr))
+ dev_err(&ctlr->dev,
+ "failed to unprepare transfer hardware\n");
+ spi_idle_runtime_pm(ctlr);
+ }
+
+ mutex_unlock(&ctlr->io_mutex);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * Utility methods for SPI protocol drivers, layered on
+ * top of the core. Some other utility methods are defined as
+ * inline functions.
+ */
+
+static void spi_complete(void *arg)
+{
+ complete(arg);
+}
+
+static int __spi_sync(struct spi_device *spi, struct spi_message *message)
+{
+ DECLARE_COMPLETION_ONSTACK(done);
+ int status;
+ struct spi_controller *ctlr = spi->controller;
+
+ if (__spi_check_suspended(ctlr)) {
+ dev_warn_once(&spi->dev, "Attempted to sync while suspend\n");
+ return -ESHUTDOWN;
+ }
+
+ status = __spi_validate(spi, message);
+ if (status != 0)
+ return status;
+
+ message->spi = spi;
+
+ SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync);
+ SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync);
+
+ /*
+ * Checking queue_empty here only guarantees async/sync message
+ * ordering when coming from the same context. It does not need to
+ * guard against reentrancy from a different context. The io_mutex
+ * will catch those cases.
+ */
+ if (READ_ONCE(ctlr->queue_empty) && !ctlr->must_async) {
+ message->actual_length = 0;
+ message->status = -EINPROGRESS;
+
+ trace_spi_message_submit(message);
+
+ SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync_immediate);
+ SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync_immediate);
+
+ __spi_transfer_message_noqueue(ctlr, message);
+
+ return message->status;
+ }
+
+ /*
+ * There are messages in the async queue that could have originated
+ * from the same context, so we need to preserve ordering.
+ * Therefor we send the message to the async queue and wait until they
+ * are completed.
+ */
+ message->complete = spi_complete;
+ message->context = &done;
+ status = spi_async_locked(spi, message);
+ if (status == 0) {
+ wait_for_completion(&done);
+ status = message->status;
+ }
+ message->context = NULL;
+
+ return status;
+}
+
+/**
+ * spi_sync - blocking/synchronous SPI data transfers
+ * @spi: device with which data will be exchanged
+ * @message: describes the data transfers
+ * Context: can sleep
+ *
+ * This call may only be used from a context that may sleep. The sleep
+ * is non-interruptible, and has no timeout. Low-overhead controller
+ * drivers may DMA directly into and out of the message buffers.
+ *
+ * Note that the SPI device's chip select is active during the message,
+ * and then is normally disabled between messages. Drivers for some
+ * frequently-used devices may want to minimize costs of selecting a chip,
+ * by leaving it selected in anticipation that the next message will go
+ * to the same chip. (That may increase power usage.)
+ *
+ * Also, the caller is guaranteeing that the memory associated with the
+ * message will not be freed before this call returns.
+ *
+ * Return: zero on success, else a negative error code.
+ */
+int spi_sync(struct spi_device *spi, struct spi_message *message)
+{
+ int ret;
+
+ mutex_lock(&spi->controller->bus_lock_mutex);
+ ret = __spi_sync(spi, message);
+ mutex_unlock(&spi->controller->bus_lock_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(spi_sync);
+
+/**
+ * spi_sync_locked - version of spi_sync with exclusive bus usage
+ * @spi: device with which data will be exchanged
+ * @message: describes the data transfers
+ * Context: can sleep
+ *
+ * This call may only be used from a context that may sleep. The sleep
+ * is non-interruptible, and has no timeout. Low-overhead controller
+ * drivers may DMA directly into and out of the message buffers.
+ *
+ * This call should be used by drivers that require exclusive access to the
+ * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
+ * be released by a spi_bus_unlock call when the exclusive access is over.
+ *
+ * Return: zero on success, else a negative error code.
+ */
+int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
+{
+ return __spi_sync(spi, message);
+}
+EXPORT_SYMBOL_GPL(spi_sync_locked);
+
+/**
+ * spi_bus_lock - obtain a lock for exclusive SPI bus usage
+ * @ctlr: SPI bus master that should be locked for exclusive bus access
+ * Context: can sleep
+ *
+ * This call may only be used from a context that may sleep. The sleep
+ * is non-interruptible, and has no timeout.
+ *
+ * This call should be used by drivers that require exclusive access to the
+ * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
+ * exclusive access is over. Data transfer must be done by spi_sync_locked
+ * and spi_async_locked calls when the SPI bus lock is held.
+ *
+ * Return: always zero.
+ */
+int spi_bus_lock(struct spi_controller *ctlr)
+{
+ unsigned long flags;
+
+ mutex_lock(&ctlr->bus_lock_mutex);
+
+ spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
+ ctlr->bus_lock_flag = 1;
+ spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
+
+ /* Mutex remains locked until spi_bus_unlock() is called */
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(spi_bus_lock);
+
+/**
+ * spi_bus_unlock - release the lock for exclusive SPI bus usage
+ * @ctlr: SPI bus master that was locked for exclusive bus access
+ * Context: can sleep
+ *
+ * This call may only be used from a context that may sleep. The sleep
+ * is non-interruptible, and has no timeout.
+ *
+ * This call releases an SPI bus lock previously obtained by an spi_bus_lock
+ * call.
+ *
+ * Return: always zero.
+ */
+int spi_bus_unlock(struct spi_controller *ctlr)
+{
+ ctlr->bus_lock_flag = 0;
+
+ mutex_unlock(&ctlr->bus_lock_mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(spi_bus_unlock);
+
+/* Portable code must never pass more than 32 bytes */
+#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
+
+static u8 *buf;
+
+/**
+ * spi_write_then_read - SPI synchronous write followed by read
+ * @spi: device with which data will be exchanged
+ * @txbuf: data to be written (need not be dma-safe)
+ * @n_tx: size of txbuf, in bytes
+ * @rxbuf: buffer into which data will be read (need not be dma-safe)
+ * @n_rx: size of rxbuf, in bytes
+ * Context: can sleep
+ *
+ * This performs a half duplex MicroWire style transaction with the
+ * device, sending txbuf and then reading rxbuf. The return value
+ * is zero for success, else a negative errno status code.
+ * This call may only be used from a context that may sleep.
+ *
+ * Parameters to this routine are always copied using a small buffer.
+ * Performance-sensitive or bulk transfer code should instead use
+ * spi_{async,sync}() calls with dma-safe buffers.
+ *
+ * Return: zero on success, else a negative error code.
+ */
+int spi_write_then_read(struct spi_device *spi,
+ const void *txbuf, unsigned n_tx,
+ void *rxbuf, unsigned n_rx)
+{
+ static DEFINE_MUTEX(lock);
+
+ int status;
+ struct spi_message message;
+ struct spi_transfer x[2];
+ u8 *local_buf;
+
+ /*
+ * Use preallocated DMA-safe buffer if we can. We can't avoid
+ * copying here, (as a pure convenience thing), but we can
+ * keep heap costs out of the hot path unless someone else is
+ * using the pre-allocated buffer or the transfer is too large.
+ */
+ if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
+ local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
+ GFP_KERNEL | GFP_DMA);
+ if (!local_buf)
+ return -ENOMEM;
+ } else {
+ local_buf = buf;
+ }
+
+ spi_message_init(&message);
+ memset(x, 0, sizeof(x));
+ if (n_tx) {
+ x[0].len = n_tx;
+ spi_message_add_tail(&x[0], &message);
+ }
+ if (n_rx) {
+ x[1].len = n_rx;
+ spi_message_add_tail(&x[1], &message);
+ }
+
+ memcpy(local_buf, txbuf, n_tx);
+ x[0].tx_buf = local_buf;
+ x[1].rx_buf = local_buf + n_tx;
+
+ /* Do the i/o */
+ status = spi_sync(spi, &message);
+ if (status == 0)
+ memcpy(rxbuf, x[1].rx_buf, n_rx);
+
+ if (x[0].tx_buf == buf)
+ mutex_unlock(&lock);
+ else
+ kfree(local_buf);
+
+ return status;
+}
+EXPORT_SYMBOL_GPL(spi_write_then_read);
+
+/*-------------------------------------------------------------------------*/
+
+#if IS_ENABLED(CONFIG_OF_DYNAMIC)
+/* Must call put_device() when done with returned spi_device device */
+static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
+{
+ struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
+
+ return dev ? to_spi_device(dev) : NULL;
+}
+
+/* The spi controllers are not using spi_bus, so we find it with another way */
+static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
+{
+ struct device *dev;
+
+ dev = class_find_device_by_of_node(&spi_master_class, node);
+ if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
+ dev = class_find_device_by_of_node(&spi_slave_class, node);
+ if (!dev)
+ return NULL;
+
+ /* Reference got in class_find_device */
+ return container_of(dev, struct spi_controller, dev);
+}
+
+static int of_spi_notify(struct notifier_block *nb, unsigned long action,
+ void *arg)
+{
+ struct of_reconfig_data *rd = arg;
+ struct spi_controller *ctlr;
+ struct spi_device *spi;
+
+ switch (of_reconfig_get_state_change(action, arg)) {
+ case OF_RECONFIG_CHANGE_ADD:
+ ctlr = of_find_spi_controller_by_node(rd->dn->parent);
+ if (ctlr == NULL)
+ return NOTIFY_OK; /* Not for us */
+
+ if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
+ put_device(&ctlr->dev);
+ return NOTIFY_OK;
+ }
+
+ /*
+ * Clear the flag before adding the device so that fw_devlink
+ * doesn't skip adding consumers to this device.
+ */
+ rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
+ spi = of_register_spi_device(ctlr, rd->dn);
+ put_device(&ctlr->dev);
+
+ if (IS_ERR(spi)) {
+ pr_err("%s: failed to create for '%pOF'\n",
+ __func__, rd->dn);
+ of_node_clear_flag(rd->dn, OF_POPULATED);
+ return notifier_from_errno(PTR_ERR(spi));
+ }
+ break;
+
+ case OF_RECONFIG_CHANGE_REMOVE:
+ /* Already depopulated? */
+ if (!of_node_check_flag(rd->dn, OF_POPULATED))
+ return NOTIFY_OK;
+
+ /* Find our device by node */
+ spi = of_find_spi_device_by_node(rd->dn);
+ if (spi == NULL)
+ return NOTIFY_OK; /* No? not meant for us */
+
+ /* Unregister takes one ref away */
+ spi_unregister_device(spi);
+
+ /* And put the reference of the find */
+ put_device(&spi->dev);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block spi_of_notifier = {
+ .notifier_call = of_spi_notify,
+};
+#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
+extern struct notifier_block spi_of_notifier;
+#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
+
+#if IS_ENABLED(CONFIG_ACPI)
+static int spi_acpi_controller_match(struct device *dev, const void *data)
+{
+ return ACPI_COMPANION(dev->parent) == data;
+}
+
+static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
+{
+ struct device *dev;
+
+ dev = class_find_device(&spi_master_class, NULL, adev,
+ spi_acpi_controller_match);
+ if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
+ dev = class_find_device(&spi_slave_class, NULL, adev,
+ spi_acpi_controller_match);
+ if (!dev)
+ return NULL;
+
+ return container_of(dev, struct spi_controller, dev);
+}
+
+static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
+{
+ struct device *dev;
+
+ dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
+ return to_spi_device(dev);
+}
+
+static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
+ void *arg)
+{
+ struct acpi_device *adev = arg;
+ struct spi_controller *ctlr;
+ struct spi_device *spi;
+
+ switch (value) {
+ case ACPI_RECONFIG_DEVICE_ADD:
+ ctlr = acpi_spi_find_controller_by_adev(acpi_dev_parent(adev));
+ if (!ctlr)
+ break;
+
+ acpi_register_spi_device(ctlr, adev);
+ put_device(&ctlr->dev);
+ break;
+ case ACPI_RECONFIG_DEVICE_REMOVE:
+ if (!acpi_device_enumerated(adev))
+ break;
+
+ spi = acpi_spi_find_device_by_adev(adev);
+ if (!spi)
+ break;
+
+ spi_unregister_device(spi);
+ put_device(&spi->dev);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block spi_acpi_notifier = {
+ .notifier_call = acpi_spi_notify,
+};
+#else
+extern struct notifier_block spi_acpi_notifier;
+#endif
+
+static int __init spi_init(void)
+{
+ int status;
+
+ buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
+ if (!buf) {
+ status = -ENOMEM;
+ goto err0;
+ }
+
+ status = bus_register(&spi_bus_type);
+ if (status < 0)
+ goto err1;
+
+ status = class_register(&spi_master_class);
+ if (status < 0)
+ goto err2;
+
+ if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
+ status = class_register(&spi_slave_class);
+ if (status < 0)
+ goto err3;
+ }
+
+ if (IS_ENABLED(CONFIG_OF_DYNAMIC))
+ WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
+ if (IS_ENABLED(CONFIG_ACPI))
+ WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
+
+ return 0;
+
+err3:
+ class_unregister(&spi_master_class);
+err2:
+ bus_unregister(&spi_bus_type);
+err1:
+ kfree(buf);
+ buf = NULL;
+err0:
+ return status;
+}
+
+/*
+ * A board_info is normally registered in arch_initcall(),
+ * but even essential drivers wait till later.
+ *
+ * REVISIT only boardinfo really needs static linking. The rest (device and
+ * driver registration) _could_ be dynamically linked (modular) ... Costs
+ * include needing to have boardinfo data structures be much more public.
+ */
+postcore_initcall(spi_init);