/*
- * spi.c - SPI init/core code
+ * SPI init/core code
*
* Copyright (C) 2005 David Brownell
*
#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>
-
-/* SPI bustype and spi_master class are registered after board init code
- * provides the SPI device tables, ensuring that both are present by the
- * time controller driver registration causes spi_devices to "enumerate".
- */
static void spidev_release(struct device *dev)
{
struct spi_device *spi = to_spi_device(dev);
spi->master->cleanup(spi);
spi_master_put(spi->master);
- kfree(dev);
+ kfree(spi);
}
static ssize_t
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;
+
if (sdrv->id_table)
return !!spi_match_id(sdrv->id_table, spi);
return 0;
}
-#ifdef CONFIG_PM
-
-static int spi_suspend(struct device *dev, pm_message_t message)
+#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);
return value;
}
-static int spi_resume(struct device *dev)
+static int spi_legacy_resume(struct device *dev)
{
int value = 0;
struct spi_driver *drv = to_spi_driver(dev->driver);
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_suspend NULL
-#define spi_resume NULL
+#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,
- .suspend = spi_suspend,
- .resume = spi_resume,
+ .pm = &spi_pm,
};
EXPORT_SYMBOL_GPL(spi_bus_type);
struct boardinfo {
struct list_head list;
- unsigned n_board_info;
- struct spi_board_info board_info[0];
+ 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);
/**
{
static DEFINE_MUTEX(spi_add_lock);
struct device *dev = spi->master->dev.parent;
+ struct device *d;
int status;
/* Chipselects are numbered 0..max; validate. */
*/
mutex_lock(&spi_add_lock);
- if (bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev))
- != NULL) {
+ 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;
}
*/
status = spi_setup(spi);
if (status < 0) {
- dev_err(dev, "can't %s %s, status %d\n",
- "setup", dev_name(&spi->dev), status);
+ 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 %s %s, status %d\n",
- "add", dev_name(&spi->dev), status);
+ 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));
}
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
int __init
spi_register_board_info(struct spi_board_info const *info, unsigned n)
{
- struct boardinfo *bi;
+ struct boardinfo *bi;
+ int i;
- bi = kmalloc(sizeof(*bi) + n * sizeof *info, GFP_KERNEL);
+ bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
if (!bi)
return -ENOMEM;
- bi->n_board_info = n;
- memcpy(bi->board_info, info, n * sizeof *info);
-
- mutex_lock(&board_lock);
- list_add_tail(&bi->list, &board_list);
- mutex_unlock(&board_lock);
- return 0;
-}
-
-/* FIXME someone should add support for a __setup("spi", ...) that
- * creates board info from kernel command lines
- */
-static void scan_boardinfo(struct spi_master *master)
-{
- struct boardinfo *bi;
+ for (i = 0; i < n; i++, bi++, info++) {
+ struct spi_master *master;
- mutex_lock(&board_lock);
- list_for_each_entry(bi, &board_list, list) {
- struct spi_board_info *chip = bi->board_info;
- unsigned n;
-
- for (n = bi->n_board_info; n > 0; n--, chip++) {
- if (chip->bus_num != master->bus_num)
- continue;
- /* NOTE: this relies on spi_new_device to
- * issue diagnostics when given bogus inputs
- */
- (void) spi_new_device(master, chip);
- }
+ 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);
}
- mutex_unlock(&board_lock);
+
+ return 0;
}
/*-------------------------------------------------------------------------*/
{
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;
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_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
dynamic ? " (dynamic)" : "");
- /* populate children from any spi device tables */
- scan_boardinfo(master);
+ 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);
+
status = 0;
+
+ /* 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 *master_dev)
+static int __unregister(struct device *dev, void *null)
{
- /* note: before about 2.6.14-rc1 this would corrupt memory: */
- if (dev != master_dev)
- spi_unregister_device(to_spi_device(dev));
+ spi_unregister_device(to_spi_device(dev));
return 0;
}
{
int dummy;
- dummy = device_for_each_child(master->dev.parent, &master->dev,
- __unregister);
+ 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);
*/
bad_bits = spi->mode & ~spi->master->mode_bits;
if (bad_bits) {
- dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
+ dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
bad_bits);
return -EINVAL;
}
}
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
int spi_async(struct spi_device *spi, struct spi_message *message)
{
struct spi_master *master = spi->master;
+ int ret;
+ unsigned long flags;
- /* 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;
+ spin_lock_irqsave(&master->bus_lock_spinlock, 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;
- }
- }
+ if (master->bus_lock_flag)
+ ret = -EBUSY;
+ else
+ ret = __spi_async(spi, message);
- message->spi = spi;
- message->status = -EINPROGRESS;
- return master->transfer(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);
+
/*-------------------------------------------------------------------------*/
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
*/
int spi_sync(struct spi_device *spi, struct spi_message *message)
{
- DECLARE_COMPLETION_ONSTACK(done);
- int status;
-
- message->complete = spi_complete;
- message->context = &done;
- status = spi_async(spi, message);
- if (status == 0) {
- wait_for_completion(&done);
- status = message->status;
- }
- message->context = NULL;
- return status;
+ 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)
* spi_{async,sync}() calls with dma-safe buffers.
*/
int spi_write_then_read(struct spi_device *spi,
- const u8 *txbuf, unsigned n_tx,
- u8 *rxbuf, unsigned n_rx)
+ const void *txbuf, unsigned n_tx,
+ void *rxbuf, unsigned n_rx)
{
static DEFINE_MUTEX(lock);
Code Review / linux-2.6.git / blobdiff