i2c: add i2c_master_{send|recv}_dmasafe
Use the new helper to create variants of i2c_master_{send|recv} which
mark their buffers as DMA safe.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
(cherry picked from commit ba98645c7d54640f163096cda3609d4d55c6ae54)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 375392c..a099c3a 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -81,6 +81,22 @@
};
/**
+ * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
+ * using a DMA safe buffer
+ * @client: Handle to slave device
+ * @buf: Where to store data read from slave, must be safe to use with DMA
+ * @count: How many bytes to read, must be less than 64k since msg.len is u16
+ *
+ * Returns negative errno, or else the number of bytes read.
+ */
+static inline int i2c_master_recv_dmasafe(const struct i2c_client *client,
+ char *buf, int count)
+{
+ return i2c_transfer_buffer_flags(client, buf, count,
+ I2C_M_RD | I2C_M_DMA_SAFE);
+};
+
+/**
* i2c_master_send - issue a single I2C message in master transmit mode
* @client: Handle to slave device
* @buf: Data that will be written to the slave
@@ -94,6 +110,22 @@
return i2c_transfer_buffer_flags(client, (char *)buf, count, 0);
};
+/**
+ * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
+ * using a DMA safe buffer
+ * @client: Handle to slave device
+ * @buf: Data that will be written to the slave, must be safe to use with DMA
+ * @count: How many bytes to write, must be less than 64k since msg.len is u16
+ *
+ * Returns negative errno, or else the number of bytes written.
+ */
+static inline int i2c_master_send_dmasafe(const struct i2c_client *client,
+ const char *buf, int count)
+{
+ return i2c_transfer_buffer_flags(client, (char *)buf, count,
+ I2C_M_DMA_SAFE);
+};
+
/* Transfer num messages.
*/
extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
