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-rw-r--r--drivers/spi/spi.c85
1 files changed, 84 insertions, 1 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 70845ccd85c3..b76f2468a84a 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -23,6 +23,7 @@
#include <linux/init.h>
#include <linux/cache.h>
#include <linux/mutex.h>
+#include <linux/mod_devicetable.h>
#include <linux/spi/spi.h>
@@ -59,9 +60,32 @@ static struct device_attribute spi_dev_attrs[] = {
* and the sysfs version makes coldplug work too.
*/
+static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
+ const struct spi_device *sdev)
+{
+ while (id->name[0]) {
+ if (!strcmp(sdev->modalias, id->name))
+ return id;
+ id++;
+ }
+ return NULL;
+}
+
+const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
+{
+ const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
+
+ return spi_match_id(sdrv->id_table, sdev);
+}
+EXPORT_SYMBOL_GPL(spi_get_device_id);
+
static int spi_match_device(struct device *dev, struct device_driver *drv)
{
const struct spi_device *spi = to_spi_device(dev);
+ const struct spi_driver *sdrv = to_spi_driver(drv);
+
+ if (sdrv->id_table)
+ return !!spi_match_id(sdrv->id_table, spi);
return strcmp(spi->modalias, drv->name) == 0;
}
@@ -70,7 +94,7 @@ 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", spi->modalias);
+ add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
return 0;
}
@@ -639,6 +663,65 @@ int spi_setup(struct spi_device *spi)
}
EXPORT_SYMBOL_GPL(spi_setup);
+/**
+ * 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;
+
+ /* 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);
+}
+EXPORT_SYMBOL_GPL(spi_async);
+
/*-------------------------------------------------------------------------*/