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Commit ba98645c authored by Wolfram Sang's avatar Wolfram Sang Committed by Wolfram Sang
Browse files

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: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 8a91732b

include/linux/i2c.h

+32 −0
Original line number Diff line number Diff line
@@ -80,6 +80,22 @@ static inline int i2c_master_recv(const struct i2c_client *client, 
	return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD);

};



/**

 * 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
@@ -94,6 +110,22 @@ static inline int i2c_master_send(const struct i2c_client *client, 
	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,