From: luowei <lw@rock-chips.com>
Date: Fri, 7 Mar 2014 11:06:04 +0000 (+0800)
Subject: add spi_write_and_read interface for spi
X-Git-Tag: firefly_0821_release~6165^2~7^2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9f2f43526db641600690f4f330df0a1b038a6edf;p=firefly-linux-kernel-4.4.55.git

add spi_write_and_read interface for spi
---

diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
old mode 100644
new mode 100755
index 6ff26c8db7b9..28c101bf79f5
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -716,6 +716,23 @@ spi_read(struct spi_device *spi, void *buf, size_t len)
 	return spi_sync(spi, &m);
 }
 
+
+static inline int
+spi_write_and_read(struct spi_device *spi, const void *tx_buf, void *rx_buf, size_t len)
+{
+        struct spi_transfer     t = {
+                        .tx_buf         = tx_buf,
+                        .rx_buf         = rx_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