[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/drivers/spi/spi.c b/ap/os/linux/linux-3.4.x/drivers/spi/spi.c
new file mode 100644
index 0000000..ea6633e
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/spi/spi.c
@@ -0,0 +1,1513 @@
+/*
+ * SPI init/core code
+ *
+ * Copyright (C) 2005 David Brownell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/cache.h>
+#include <linux/mutex.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+#include <linux/mod_devicetable.h>
+#include <linux/spi/spi.h>
+#include <linux/of_spi.h>
+#include <linux/pm_runtime.h>
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+
+static void spidev_release(struct device *dev)
+{
+ struct spi_device *spi = to_spi_device(dev);
+
+ if (!dev)
+ return;
+
+ /* spi masters may cleanup for released devices */
+ if (spi->master->cleanup)
+ spi->master->cleanup(spi);
+
+ spi_master_put(spi->master);
+ 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);
+
+ return sprintf(buf, "%s\n", spi->modalias);
+}
+
+static struct device_attribute spi_dev_attrs[] = {
+ __ATTR_RO(modalias),
+ __ATTR_NULL,
+};
+
+/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
+ * and the sysfs version makes coldplug work too.
+ */
+
+static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
+ const struct spi_device *sdev)
+{
+ while (id->name[0]) {
+ if (!strcmp(sdev->modalias, id->name))
+ return id;
+ id++;
+ }
+ return NULL;
+}
+
+const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
+{
+ const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
+
+#ifdef CONFIG_KLOCWORK
+ if (!sdrv)
+ return NULL;
+#endif
+
+ return spi_match_id(sdrv->id_table, sdev);
+}
+EXPORT_SYMBOL_GPL(spi_get_device_id);
+
+static int spi_match_device(struct device *dev, struct device_driver *drv)
+{
+ const struct spi_device *spi = to_spi_device(dev);
+ const struct spi_driver *sdrv = to_spi_driver(drv);
+
+ /* Attempt an OF style match */
+ if (of_driver_match_device(dev, drv))
+ return 1;
+
+#ifdef CONFIG_KLOCWORK
+ if (!dev || !drv)
+ return -ENODEV;
+#endif
+
+ if (sdrv->id_table)
+ return !!spi_match_id(sdrv->id_table, spi);
+
+ return strcmp(spi->modalias, drv->name) == 0;
+}
+
+static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+ const struct spi_device *spi = to_spi_device(dev);
+
+ add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int spi_legacy_suspend(struct device *dev, pm_message_t message)
+{
+ int value = 0;
+ struct spi_driver *drv = to_spi_driver(dev->driver);
+
+ /* suspend will stop irqs and dma; no more i/o */
+ if (drv) {
+ if (drv->suspend)
+ value = drv->suspend(to_spi_device(dev), message);
+ else
+ dev_dbg(dev, "... can't suspend\n");
+ }
+ return value;
+}
+
+static int spi_legacy_resume(struct device *dev)
+{
+ int value = 0;
+ struct spi_driver *drv = to_spi_driver(dev->driver);
+
+ /* resume may restart the i/o queue */
+ if (drv) {
+ if (drv->resume)
+ value = drv->resume(to_spi_device(dev));
+ else
+ dev_dbg(dev, "... can't resume\n");
+ }
+ return value;
+}
+
+static int spi_pm_suspend(struct device *dev)
+{
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+ if (pm)
+ return pm_generic_suspend(dev);
+ else
+ return spi_legacy_suspend(dev, PMSG_SUSPEND);
+}
+
+static int spi_pm_resume(struct device *dev)
+{
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+ if (pm)
+ return pm_generic_resume(dev);
+ else
+ return spi_legacy_resume(dev);
+}
+
+static int spi_pm_freeze(struct device *dev)
+{
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+ if (pm)
+ return pm_generic_freeze(dev);
+ else
+ return spi_legacy_suspend(dev, PMSG_FREEZE);
+}
+
+static int spi_pm_thaw(struct device *dev)
+{
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+ if (pm)
+ return pm_generic_thaw(dev);
+ else
+ return spi_legacy_resume(dev);
+}
+
+static int spi_pm_poweroff(struct device *dev)
+{
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+ if (pm)
+ return pm_generic_poweroff(dev);
+ else
+ return spi_legacy_suspend(dev, PMSG_HIBERNATE);
+}
+
+static int spi_pm_restore(struct device *dev)
+{
+ const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+ if (pm)
+ return pm_generic_restore(dev);
+ else
+ return spi_legacy_resume(dev);
+}
+#else
+#define spi_pm_suspend NULL
+#define spi_pm_resume NULL
+#define spi_pm_freeze NULL
+#define spi_pm_thaw NULL
+#define spi_pm_poweroff NULL
+#define spi_pm_restore NULL
+#endif
+
+static const struct dev_pm_ops spi_pm = {
+ .suspend = spi_pm_suspend,
+ .resume = spi_pm_resume,
+ .freeze = spi_pm_freeze,
+ .thaw = spi_pm_thaw,
+ .poweroff = spi_pm_poweroff,
+ .restore = spi_pm_restore,
+ SET_RUNTIME_PM_OPS(
+ pm_generic_runtime_suspend,
+ pm_generic_runtime_resume,
+ pm_generic_runtime_idle
+ )
+};
+
+struct bus_type spi_bus_type = {
+ .name = "spi",
+ .dev_attrs = spi_dev_attrs,
+ .match = spi_match_device,
+ .uevent = spi_uevent,
+ .pm = &spi_pm,
+};
+EXPORT_SYMBOL_GPL(spi_bus_type);
+
+
+static int spi_drv_probe(struct device *dev)
+{
+ const struct spi_driver *sdrv = to_spi_driver(dev->driver);
+
+#ifdef CONFIG_KLOCWORK
+ if (!sdrv)
+ return -ENODEV;
+#endif
+
+ return sdrv->probe(to_spi_device(dev));
+}
+
+static int spi_drv_remove(struct device *dev)
+{
+ const struct spi_driver *sdrv = to_spi_driver(dev->driver);
+
+#ifdef CONFIG_KLOCWORK
+ if (!sdrv)
+ return -ENODEV;
+#endif
+
+ return sdrv->remove(to_spi_device(dev));
+}
+
+static void spi_drv_shutdown(struct device *dev)
+{
+ const struct spi_driver *sdrv = to_spi_driver(dev->driver);
+
+#ifdef CONFIG_KLOCWORK
+ if (!sdrv)
+ return;
+#endif
+
+ sdrv->shutdown(to_spi_device(dev));
+}
+
+/**
+ * spi_register_driver - register a SPI driver
+ * @sdrv: the driver to register
+ * Context: can sleep
+ */
+int spi_register_driver(struct spi_driver *sdrv)
+{
+ sdrv->driver.bus = &spi_bus_type;
+ if (sdrv->probe)
+ sdrv->driver.probe = spi_drv_probe;
+ if (sdrv->remove)
+ sdrv->driver.remove = spi_drv_remove;
+ if (sdrv->shutdown)
+ sdrv->driver.shutdown = spi_drv_shutdown;
+ return driver_register(&sdrv->driver);
+}
+EXPORT_SYMBOL_GPL(spi_register_driver);
+
+/*-------------------------------------------------------------------------*/
+
+/* SPI devices should normally not be created by SPI device drivers; that
+ * would make them board-specific. Similarly with SPI master 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_master_list);
+
+/*
+ * Used to protect add/del opertion for board_info list and
+ * spi_master list, and their matching process
+ */
+static DEFINE_MUTEX(board_lock);
+
+/**
+ * spi_alloc_device - Allocate a new SPI device
+ * @master: 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 master. If the caller
+ * needs to discard the spi_device without adding it, then it should
+ * call spi_dev_put() on it.
+ *
+ * Returns a pointer to the new device, or NULL.
+ */
+struct spi_device *spi_alloc_device(struct spi_master *master)
+{
+ struct spi_device *spi;
+ struct device *dev = master->dev.parent;
+
+ if (!spi_master_get(master))
+ return NULL;
+
+ spi = kzalloc(sizeof *spi, GFP_KERNEL);
+ if (!spi) {
+ dev_err(dev, "cannot alloc spi_device\n");
+ spi_master_put(master);
+ return NULL;
+ }
+
+ spi->master = master;
+ spi->dev.parent = &master->dev;
+ spi->dev.bus = &spi_bus_type;
+ spi->dev.release = spidev_release;
+ device_initialize(&spi->dev);
+ return spi;
+}
+EXPORT_SYMBOL_GPL(spi_alloc_device);
+
+/**
+ * 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.
+ *
+ * Returns 0 on success; negative errno on failure
+ */
+int spi_add_device(struct spi_device *spi)
+{
+ static DEFINE_MUTEX(spi_add_lock);
+ struct device *dev = spi->master->dev.parent;
+ struct device *d;
+ int status;
+
+ /* Chipselects are numbered 0..max; validate. */
+ if (spi->chip_select >= spi->master->num_chipselect) {
+ dev_err(dev, "cs%d >= max %d\n",
+ spi->chip_select,
+ spi->master->num_chipselect);
+ return -EINVAL;
+ }
+
+ /* Set the bus ID string */
+ dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),
+ spi->chip_select);
+
+
+ /* We need to make sure there's no other device with this
+ * chipselect **BEFORE** we call setup(), else we'll trash
+ * its configuration. Lock against concurrent add() calls.
+ */
+ mutex_lock(&spi_add_lock);
+
+ d = bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev));
+ if (d != NULL) {
+ dev_err(dev, "chipselect %d already in use\n",
+ spi->chip_select);
+ put_device(d);
+ status = -EBUSY;
+ goto done;
+ }
+
+ /* Drivers may modify this initial i/o setup, but will
+ * normally rely on the device being setup. Devices
+ * using SPI_CS_HIGH can't coexist well otherwise...
+ */
+ status = spi_setup(spi);
+ if (status < 0) {
+ dev_err(dev, "can't setup %s, status %d\n",
+ dev_name(&spi->dev), status);
+ goto done;
+ }
+
+ /* Device may be bound to an active driver when this returns */
+ status = device_add(&spi->dev);
+ if (status < 0)
+ dev_err(dev, "can't add %s, status %d\n",
+ dev_name(&spi->dev), status);
+ else
+ dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
+
+done:
+ mutex_unlock(&spi_add_lock);
+ return status;
+}
+EXPORT_SYMBOL_GPL(spi_add_device);
+
+/**
+ * spi_new_device - instantiate one new SPI device
+ * @master: 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).
+ *
+ * Returns the new device, or NULL.
+ */
+struct spi_device *spi_new_device(struct spi_master *master,
+ 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(master);
+ if (!proxy)
+ return NULL;
+
+ WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
+
+ proxy->chip_select = chip->chip_select;
+ proxy->max_speed_hz = chip->max_speed_hz;
+ proxy->mode = chip->mode;
+ proxy->irq = chip->irq;
+ strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
+ proxy->dev.platform_data = (void *) chip->platform_data;
+ proxy->controller_data = chip->controller_data;
+ proxy->controller_state = NULL;
+
+ status = spi_add_device(proxy);
+ if (status < 0) {
+ spi_dev_put(proxy);
+ return NULL;
+ }
+
+ return proxy;
+}
+EXPORT_SYMBOL_GPL(spi_new_device);
+
+static void spi_match_master_to_boardinfo(struct spi_master *master,
+ struct spi_board_info *bi)
+{
+ struct spi_device *dev;
+
+ if (master->bus_num != bi->bus_num)
+ return;
+
+ dev = spi_new_device(master, bi);
+ if (!dev)
+ dev_err(master->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.
+ */
+int __devinit
+spi_register_board_info(struct spi_board_info const *info, unsigned n)
+{
+ struct boardinfo *bi;
+ int i;
+
+ if (!n)
+ return 0;
+
+ bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
+ if (!bi)
+ return -ENOMEM;
+
+ for (i = 0; i < n; i++, bi++, info++) {
+ struct spi_master *master;
+
+ memcpy(&bi->board_info, info, sizeof(*info));
+ mutex_lock(&board_lock);
+ list_add_tail(&bi->list, &board_list);
+ list_for_each_entry(master, &spi_master_list, list)
+ spi_match_master_to_boardinfo(master, &bi->board_info);
+ mutex_unlock(&board_lock);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(spi_register_board_info);
+/*-------------------------------------------------------------------------*/
+
+/**
+ * spi_pump_messages - kthread work function which processes spi message queue
+ * @work: pointer to kthread work struct contained in the master struct
+ *
+ * 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.
+ *
+ */
+static void spi_pump_messages(struct kthread_work *work)
+{
+ struct spi_master *master =
+ container_of(work, struct spi_master, pump_messages);
+ unsigned long flags;
+ bool was_busy = false;
+ int ret;
+
+ /* Lock queue and check for queue work */
+ spin_lock_irqsave(&master->queue_lock, flags);
+ if (list_empty(&master->queue) || !master->running) {
+ if (master->busy) {
+ ret = master->unprepare_transfer_hardware(master);
+ if (ret) {
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+ dev_err(&master->dev,
+ "failed to unprepare transfer hardware\n");
+ return;
+ }
+ }
+ master->busy = false;
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+ return;
+ }
+
+ /* Make sure we are not already running a message */
+ if (master->cur_msg) {
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+ return;
+ }
+ /* Extract head of queue */
+ master->cur_msg =
+ list_entry(master->queue.next, struct spi_message, queue);
+
+ list_del_init(&master->cur_msg->queue);
+ if (master->busy)
+ was_busy = true;
+ else
+ master->busy = true;
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+
+ if (!was_busy) {
+ ret = master->prepare_transfer_hardware(master);
+ if (ret) {
+ dev_err(&master->dev,
+ "failed to prepare transfer hardware\n");
+ return;
+ }
+ }
+
+ ret = master->transfer_one_message(master, master->cur_msg);
+ if (ret) {
+ dev_err(&master->dev,
+ "failed to transfer one message from queue\n");
+ return;
+ }
+}
+
+static int spi_init_queue(struct spi_master *master)
+{
+ struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
+
+ INIT_LIST_HEAD(&master->queue);
+ spin_lock_init(&master->queue_lock);
+
+ master->running = false;
+ master->busy = false;
+
+ init_kthread_worker(&master->kworker);
+ master->kworker_task = kthread_run(kthread_worker_fn,
+ &master->kworker,
+ dev_name(&master->dev));
+ if (IS_ERR(master->kworker_task)) {
+ dev_err(&master->dev, "failed to create message pump task\n");
+ return -ENOMEM;
+ }
+ init_kthread_work(&master->pump_messages, spi_pump_messages);
+
+ /*
+ * Master 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 (master->rt) {
+ dev_info(&master->dev,
+ "will run message pump with realtime priority\n");
+ sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m);
+ }
+
+ return 0;
+}
+
+/**
+ * spi_get_next_queued_message() - called by driver to check for queued
+ * messages
+ * @master: the master to check for queued messages
+ *
+ * If there are more messages in the queue, the next message is returned from
+ * this call.
+ */
+struct spi_message *spi_get_next_queued_message(struct spi_master *master)
+{
+ struct spi_message *next;
+ unsigned long flags;
+
+ /* get a pointer to the next message, if any */
+ spin_lock_irqsave(&master->queue_lock, flags);
+ if (list_empty(&master->queue))
+ next = NULL;
+ else
+ next = list_entry(master->queue.next,
+ struct spi_message, queue);
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+
+ return next;
+}
+EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
+
+/**
+ * spi_finalize_current_message() - the current message is complete
+ * @master: the master 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_master *master)
+{
+ struct spi_message *mesg;
+ unsigned long flags;
+
+ spin_lock_irqsave(&master->queue_lock, flags);
+ mesg = master->cur_msg;
+ master->cur_msg = NULL;
+
+ queue_kthread_work(&master->kworker, &master->pump_messages);
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+
+ mesg->state = NULL;
+ if (mesg->complete)
+ mesg->complete(mesg->context);
+}
+EXPORT_SYMBOL_GPL(spi_finalize_current_message);
+
+static int spi_start_queue(struct spi_master *master)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&master->queue_lock, flags);
+
+ if (master->running || master->busy) {
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+ return -EBUSY;
+ }
+
+ master->running = true;
+ master->cur_msg = NULL;
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+
+ queue_kthread_work(&master->kworker, &master->pump_messages);
+
+ return 0;
+}
+
+static int spi_stop_queue(struct spi_master *master)
+{
+ unsigned long flags;
+ unsigned limit = 500;
+ int ret = 0;
+
+ spin_lock_irqsave(&master->queue_lock, flags);
+
+ /*
+ * This is a bit lame, but is optimized for the common execution path.
+ * A wait_queue on the master->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(&master->queue) || master->busy) && limit--) {
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+ msleep(10);
+ spin_lock_irqsave(&master->queue_lock, flags);
+ }
+
+ if (!list_empty(&master->queue) || master->busy)
+ ret = -EBUSY;
+ else
+ master->running = false;
+
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+
+ if (ret) {
+ dev_warn(&master->dev,
+ "could not stop message queue\n");
+ return ret;
+ }
+ return ret;
+}
+
+static int spi_destroy_queue(struct spi_master *master)
+{
+ int ret;
+
+ ret = spi_stop_queue(master);
+
+ /*
+ * flush_kthread_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(&master->dev, "problem destroying queue\n");
+ return ret;
+ }
+
+ flush_kthread_worker(&master->kworker);
+ kthread_stop(master->kworker_task);
+
+ 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
+ */
+static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
+{
+ struct spi_master *master = spi->master;
+ unsigned long flags;
+
+ spin_lock_irqsave(&master->queue_lock, flags);
+
+ if (!master->running) {
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+ return -ESHUTDOWN;
+ }
+ msg->actual_length = 0;
+ msg->status = -EINPROGRESS;
+
+ list_add_tail(&msg->queue, &master->queue);
+ if (master->running && !master->busy)
+ queue_kthread_work(&master->kworker, &master->pump_messages);
+
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+ return 0;
+}
+
+static int spi_master_initialize_queue(struct spi_master *master)
+{
+ int ret;
+
+ master->queued = true;
+ master->transfer = spi_queued_transfer;
+
+ /* Initialize and start queue */
+ ret = spi_init_queue(master);
+ if (ret) {
+ dev_err(&master->dev, "problem initializing queue\n");
+ goto err_init_queue;
+ }
+ ret = spi_start_queue(master);
+ if (ret) {
+ dev_err(&master->dev, "problem starting queue\n");
+ goto err_start_queue;
+ }
+
+ return 0;
+
+err_start_queue:
+err_init_queue:
+ spi_destroy_queue(master);
+ return ret;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void spi_master_release(struct device *dev)
+{
+ struct spi_master *master;
+
+ master = container_of(dev, struct spi_master, dev);
+ kfree(master);
+}
+
+static struct class spi_master_class = {
+ .name = "spi_master",
+ .owner = THIS_MODULE,
+ .dev_release = spi_master_release,
+};
+
+
+
+/**
+ * spi_alloc_master - allocate SPI master 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_master_get_devdata().
+ * Context: can sleep
+ *
+ * This call is used only by SPI master controller drivers, which are the
+ * only ones directly touching chip registers. It's how they allocate
+ * an spi_master structure, prior to calling spi_register_master().
+ *
+ * This must be called from context that can sleep. It returns the SPI
+ * master structure on success, else NULL.
+ *
+ * The caller is responsible for assigning the bus number and initializing
+ * the master's methods before calling spi_register_master(); and (after errors
+ * adding the device) calling spi_master_put() and kfree() to prevent a memory
+ * leak.
+ */
+struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
+{
+ struct spi_master *master;
+
+ if (!dev)
+ return NULL;
+
+ master = kzalloc(size + sizeof *master, GFP_KERNEL);
+ if (!master)
+ return NULL;
+
+ device_initialize(&master->dev);
+ master->dev.class = &spi_master_class;
+ master->dev.parent = get_device(dev);
+ spi_master_set_devdata(master, &master[1]);
+
+ return master;
+}
+EXPORT_SYMBOL_GPL(spi_alloc_master);
+
+/**
+ * spi_register_master - register SPI master controller
+ * @master: initialized master, originally from spi_alloc_master()
+ * Context: can sleep
+ *
+ * SPI master 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_master() 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 master's refcount).
+ * After a successful return, the caller is responsible for calling
+ * spi_unregister_master().
+ */
+int spi_register_master(struct spi_master *master)
+{
+ static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
+ struct device *dev = master->dev.parent;
+ struct boardinfo *bi;
+ int status = -ENODEV;
+ int dynamic = 0;
+
+ if (!dev)
+ return -ENODEV;
+
+ /* even if it's just one always-selected device, there must
+ * be at least one chipselect
+ */
+ if (master->num_chipselect == 0)
+ return -EINVAL;
+
+ /* convention: dynamically assigned bus IDs count down from the max */
+ if (master->bus_num < 0) {
+ /* FIXME switch to an IDR based scheme, something like
+ * I2C now uses, so we can't run out of "dynamic" IDs
+ */
+ master->bus_num = atomic_dec_return(&dyn_bus_id);
+ dynamic = 1;
+ }
+
+ spin_lock_init(&master->bus_lock_spinlock);
+ mutex_init(&master->bus_lock_mutex);
+ master->bus_lock_flag = 0;
+
+ /* register the device, then userspace will see it.
+ * registration fails if the bus ID is in use.
+ */
+ dev_set_name(&master->dev, "spi%u", master->bus_num);
+ status = device_add(&master->dev);
+ if (status < 0)
+ goto done;
+ dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
+ dynamic ? " (dynamic)" : "");
+
+ /* If we're using a queued driver, start the queue */
+ if (master->transfer)
+ dev_info(dev, "master is unqueued, this is deprecated\n");
+ else {
+ status = spi_master_initialize_queue(master);
+ if (status) {
+ device_unregister(&master->dev);
+ goto done;
+ }
+ }
+
+ mutex_lock(&board_lock);
+ list_add_tail(&master->list, &spi_master_list);
+ list_for_each_entry(bi, &board_list, list)
+ spi_match_master_to_boardinfo(master, &bi->board_info);
+ mutex_unlock(&board_lock);
+
+ /* Register devices from the device tree */
+ of_register_spi_devices(master);
+done:
+ return status;
+}
+EXPORT_SYMBOL_GPL(spi_register_master);
+
+static int __unregister(struct device *dev, void *null)
+{
+ spi_unregister_device(to_spi_device(dev));
+ return 0;
+}
+
+/**
+ * spi_unregister_master - unregister SPI master controller
+ * @master: the master being unregistered
+ * Context: can sleep
+ *
+ * This call is used only by SPI master controller drivers, which are the
+ * only ones directly touching chip registers.
+ *
+ * This must be called from context that can sleep.
+ */
+void spi_unregister_master(struct spi_master *master)
+{
+ int dummy;
+
+ if (master->queued) {
+ if (spi_destroy_queue(master))
+ dev_err(&master->dev, "queue remove failed\n");
+ }
+
+ mutex_lock(&board_lock);
+ list_del(&master->list);
+ mutex_unlock(&board_lock);
+
+ dummy = device_for_each_child(&master->dev, NULL, __unregister);
+ device_unregister(&master->dev);
+}
+EXPORT_SYMBOL_GPL(spi_unregister_master);
+
+int spi_master_suspend(struct spi_master *master)
+{
+ int ret;
+
+ /* Basically no-ops for non-queued masters */
+ if (!master->queued)
+ return 0;
+
+ ret = spi_stop_queue(master);
+ if (ret)
+ dev_err(&master->dev, "queue stop failed\n");
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(spi_master_suspend);
+
+int spi_master_resume(struct spi_master *master)
+{
+ int ret;
+
+ if (!master->queued)
+ return 0;
+
+ ret = spi_start_queue(master);
+ if (ret)
+ dev_err(&master->dev, "queue restart failed\n");
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(spi_master_resume);
+
+static int __spi_master_match(struct device *dev, void *data)
+{
+ struct spi_master *m;
+ u16 *bus_num = data;
+
+ m = container_of(dev, struct spi_master, dev);
+ return m->bus_num == *bus_num;
+}
+
+/**
+ * spi_busnum_to_master - look up master associated with bus_num
+ * @bus_num: the master's bus number
+ * Context: can sleep
+ *
+ * This call may be used with devices that are registered after
+ * arch init time. It returns a refcounted pointer to the relevant
+ * spi_master (which the caller must release), or NULL if there is
+ * no such master registered.
+ */
+struct spi_master *spi_busnum_to_master(u16 bus_num)
+{
+ struct device *dev;
+ struct spi_master *master = NULL;
+
+ dev = class_find_device(&spi_master_class, NULL, &bus_num,
+ __spi_master_match);
+ if (dev)
+ master = container_of(dev, struct spi_master, dev);
+ /* reference got in class_find_device */
+ return master;
+}
+EXPORT_SYMBOL_GPL(spi_busnum_to_master);
+
+
+/*-------------------------------------------------------------------------*/
+
+/* Core methods for SPI master protocol drivers. Some of the
+ * other core methods are currently defined as inline functions.
+ */
+
+/**
+ * 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.
+ */
+int spi_setup(struct spi_device *spi)
+{
+ unsigned bad_bits;
+ int status;
+
+ /* help drivers fail *cleanly* when they need options
+ * that aren't supported with their current master
+ */
+ bad_bits = spi->mode & ~spi->master->mode_bits;
+ if (bad_bits) {
+ dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
+ bad_bits);
+ return -EINVAL;
+ }
+
+ if (!spi->bits_per_word)
+ spi->bits_per_word = 8;
+
+ status = spi->master->setup(spi);
+
+ dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s"
+ "%u bits/w, %u Hz max --> %d\n",
+ (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
+ (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
+ (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
+ (spi->mode & SPI_3WIRE) ? "3wire, " : "",
+ (spi->mode & SPI_LOOP) ? "loopback, " : "",
+ spi->bits_per_word, spi->max_speed_hz,
+ status);
+
+ return status;
+}
+EXPORT_SYMBOL_GPL(spi_setup);
+
+static int __spi_async(struct spi_device *spi, struct spi_message *message)
+{
+ struct spi_master *master = spi->master;
+
+ /* 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 ((master->flags & SPI_MASTER_HALF_DUPLEX)
+ || (spi->mode & SPI_3WIRE)) {
+ struct spi_transfer *xfer;
+ unsigned flags = master->flags;
+
+ list_for_each_entry(xfer, &message->transfers, transfer_list) {
+ if (xfer->rx_buf && xfer->tx_buf)
+ return -EINVAL;
+ if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
+ return -EINVAL;
+ if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
+ return -EINVAL;
+ }
+ }
+
+ message->spi = spi;
+ message->status = -EINPROGRESS;
+ return master->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.)
+ */
+int spi_async(struct spi_device *spi, struct spi_message *message)
+{
+ struct spi_master *master = spi->master;
+ int ret;
+ unsigned long flags;
+
+ spin_lock_irqsave(&master->bus_lock_spinlock, flags);
+
+ if (master->bus_lock_flag)
+ ret = -EBUSY;
+ else
+ ret = __spi_async(spi, message);
+
+ spin_unlock_irqrestore(&master->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.)
+ */
+int spi_async_locked(struct spi_device *spi, struct spi_message *message)
+{
+ struct spi_master *master = spi->master;
+ int ret;
+ unsigned long flags;
+
+ spin_lock_irqsave(&master->bus_lock_spinlock, flags);
+
+ ret = __spi_async(spi, message);
+
+ spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
+
+ return ret;
+
+}
+EXPORT_SYMBOL_GPL(spi_async_locked);
+
+
+/*-------------------------------------------------------------------------*/
+
+/* Utility methods for SPI master 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,
+ int bus_locked)
+{
+ DECLARE_COMPLETION_ONSTACK(done);
+ int status;
+ struct spi_master *master = spi->master;
+
+ message->complete = spi_complete;
+ message->context = &done;
+
+ if (!bus_locked)
+ mutex_lock(&master->bus_lock_mutex);
+
+ status = spi_async_locked(spi, message);
+
+ if (!bus_locked)
+ mutex_unlock(&master->bus_lock_mutex);
+
+ 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.
+ *
+ * It returns zero on success, else a negative error code.
+ */
+int spi_sync(struct spi_device *spi, struct spi_message *message)
+{
+ return __spi_sync(spi, message, 0);
+}
+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.
+ *
+ * It returns 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, 1);
+}
+EXPORT_SYMBOL_GPL(spi_sync_locked);
+
+/**
+ * spi_bus_lock - obtain a lock for exclusive SPI bus usage
+ * @master: 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.
+ *
+ * It returns zero on success, else a negative error code.
+ */
+int spi_bus_lock(struct spi_master *master)
+{
+ unsigned long flags;
+
+ mutex_lock(&master->bus_lock_mutex);
+
+ spin_lock_irqsave(&master->bus_lock_spinlock, flags);
+ master->bus_lock_flag = 1;
+ spin_unlock_irqrestore(&master->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
+ * @master: 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.
+ *
+ * It returns zero on success, else a negative error code.
+ */
+int spi_bus_unlock(struct spi_master *master)
+{
+ master->bus_lock_flag = 0;
+
+ mutex_unlock(&master->bus_lock_mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(spi_bus_unlock);
+
+/* portable code must never pass more than 32 bytes */
+#define SPI_BUFSIZ max(32,SMP_CACHE_BYTES)
+
+static u8 *buf;
+
+/**
+ * spi_write_then_read - SPI synchronous write followed by read
+ * @spi: device with which data will be exchanged
+ * @txbuf: data to be written (need not be dma-safe)
+ * @n_tx: size of txbuf, in bytes
+ * @rxbuf: buffer into which data will be read (need not be dma-safe)
+ * @n_rx: size of rxbuf, in bytes
+ * Context: can sleep
+ *
+ * This performs a half duplex MicroWire style transaction with the
+ * device, sending txbuf and then reading rxbuf. The return value
+ * is zero for success, else a negative errno status code.
+ * This call may only be used from a context that may sleep.
+ *
+ * Parameters to this routine are always copied using a small buffer;
+ * portable code should never use this for more than 32 bytes.
+ * Performance-sensitive or bulk transfer code should instead use
+ * spi_{async,sync}() calls with dma-safe buffers.
+ */
+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. We can't avoid copying here,
+ * (as a pure convenience thing), but we can keep heap costs
+ * out of the hot path ...
+ */
+ if ((n_tx + n_rx) > SPI_BUFSIZ) {
+ dev_err(&spi->dev, "total len %d > SPI_BUFSIZ %d.", (n_tx + n_rx), SPI_BUFSIZ);
+ return -EINVAL;
+ }
+
+ 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);
+ }
+
+ /* ... unless someone else is using the pre-allocated buffer */
+ if (!mutex_trylock(&lock)) {
+ local_buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
+ if (!local_buf)
+ return -ENOMEM;
+ } else
+ local_buf = buf;
+
+ 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);
+
+/*-------------------------------------------------------------------------*/
+
+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;
+ return 0;
+
+err2:
+ bus_unregister(&spi_bus_type);
+err1:
+ kfree(buf);
+ buf = NULL;
+err0:
+ return status;
+}
+
+/* board_info is normally registered in arch_initcall(),
+ * but even essential drivers wait till later
+ *
+ * REVISIT only boardinfo really needs static linking. the rest (device and
+ * driver registration) _could_ be dynamically linked (modular) ... costs
+ * include needing to have boardinfo data structures be much more public.
+ */
+postcore_initcall(spi_init);
+