Merge tag 'iio-for-3.9d' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

"4th set of IIO new drivers cleanups and fixes for the 3.9 cycle
+ a new spi helper function.

1) Introduce spi_sync_transfer and use it within IIO.  Originally
   it was envisioned that this nice little boilerplate replacement
   would go through the spi tree, but Grant Likely stated he'd
   prefer we take it through IIO as the example usecases were all
   in IIO (and are also in this pull request).  Note that given
   their may have been some unresolved elements related to the
   coccinelle element of the patch, that has been stripped out
   and will doubtlessly follow at a later date (along with
   lots of other patches for drivers elsewhere in the tree).

2) New Invensense MPU6050 driver.  This is stripped down to pretty
   much the basics from the original submission with the intent
   to build up all the fancy bits in an incremental (and hence
   reviewable fashion). It's been through a good few revisions
   so nice to finally merge this.

3) Change to iio_channel_get api to simplify device tree based
   mappings.  The actual mappings are currently under review.

4) Build fixes for !CONFIG_IIO_TRIGGER in the st_sensors driver.
   This one snuck past during review and testing but got picked
   up by Randy Dunlap in a randconfig build.

5) Some max1363 cleanups and enhancements.

6) Some comment fixes to make them coherent and comprehensible.

7) Trivial build warning fix in mxs-lradc"

1 files changed, 44 insertions, 0 deletions

diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index f629189..7dbe586 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -591,6 +591,26 @@ spi_transfer_del(struct spi_transfer *t)
 	list_del(&t->transfer_list);
 }
 
+/**
+ * spi_message_init_with_transfers - Initialize spi_message and append transfers
+ * @m: spi_message to be initialized
+ * @xfers: An array of spi transfers
+ * @num_xfers: Number of items in the xfer array
+ *
+ * This function initializes the given spi_message and adds each spi_transfer in
+ * the given array to the message.
+ */
+static inline void
+spi_message_init_with_transfers(struct spi_message *m,
+struct spi_transfer *xfers, unsigned int num_xfers)
+{
+	unsigned int i;
+
+	spi_message_init(m);
+	for (i = 0; i < num_xfers; ++i)
+		spi_message_add_tail(&xfers[i], m);
+}
+
 /* It's fine to embed message and transaction structures in other data
  * structures so long as you don't free them while they're in use.
  */
@@ -683,6 +703,30 @@ spi_read(struct spi_device *spi, void *buf, size_t len)
 	return spi_sync(spi, &m);
 }
 
+/**
+ * spi_sync_transfer - synchronous SPI data transfer
+ * @spi: device with which data will be exchanged
+ * @xfers: An array of spi_transfers
+ * @num_xfers: Number of items in the xfer array
+ * Context: can sleep
+ *
+ * Does a synchronous SPI data transfer of the given spi_transfer array.
+ *
+ * For more specific semantics see spi_sync().
+ *
+ * It returns zero on success, else a negative error code.
+ */
+static inline int
+spi_sync_transfer(struct spi_device *spi, struct spi_transfer *xfers,
+	unsigned int num_xfers)
+{
+	struct spi_message msg;
+
+	spi_message_init_with_transfers(&msg, xfers, num_xfers);
+
+	return spi_sync(spi, &msg);
+}
+
 /* this copies txbuf and rxbuf data; for small transfers only! */
 extern int spi_write_then_read(struct spi_device *spi,
 		const void *txbuf, unsigned n_tx,