spi: core: Use spi_sync_transfer() in spi_write()/spi_read()

Simplify spi_write() and spi_read() using the spi_sync_transfer()
helper.

This requires moving spi_sync_transfer() up.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/linux/spi/spi.h

@@ -979,6 +979,30 @@ extern int spi_sync_locked(struct spi_device *spi, struct spi_message *message);
 extern int spi_bus_lock(struct spi_master *master);
 extern int spi_bus_unlock(struct spi_master *master);
 
+/**
+ * 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().
+ *
+ * Return: Return: 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);
+}
+
 /**
  * spi_write - SPI synchronous write
  * @spi: device to which data will be written
@@ -998,11 +1022,8 @@ spi_write(struct spi_device *spi, const void *buf, size_t len)
 			.tx_buf		= buf,
 			.len		= len,
 		};
-	struct spi_message	m;
 
-	spi_message_init(&m);
-	spi_message_add_tail(&t, &m);
-	return spi_sync(spi, &m);
+	return spi_sync_transfer(spi, &t, 1);
 }
 
 /**
@@ -1024,35 +1045,8 @@ spi_read(struct spi_device *spi, void *buf, size_t len)
 			.rx_buf		= buf,
 			.len		= len,
 		};
-	struct spi_message	m;
 
-	spi_message_init(&m);
-	spi_message_add_tail(&t, &m);
-	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().
- *
- * Return: Return: 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);
+	return spi_sync_transfer(spi, &t, 1);
 }
 
 /* this copies txbuf and rxbuf data; for small transfers only! */