netns xfrm: fix "ip xfrm state|policy count" misreport

[safe/jmp/linux-2.6] / drivers / spi / spi.c

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 49e8486..b76f246 100644 (file)
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -663,6 +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);
+
 
 /*-------------------------------------------------------------------------*/