diff options
author | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2017-11-04 21:20:05 +0100 |
---|---|---|
committer | Wolfram Sang <wsa@the-dreams.de> | 2017-12-03 21:23:38 +0100 |
commit | ba98645c7d54640f163096cda3609d4d55c6ae54 (patch) | |
tree | 0cd75b537999b2689df0b4bc090e68932e1becfc /include/linux/i2c.h | |
parent | 8a91732b3b33454d8034e7be5c8342f028ea772e (diff) | |
download | linux-ba98645c7d54640f163096cda3609d4d55c6ae54.tar.gz linux-ba98645c7d54640f163096cda3609d4d55c6ae54.tar.bz2 linux-ba98645c7d54640f163096cda3609d4d55c6ae54.zip |
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>
Diffstat (limited to 'include/linux/i2c.h')
-rw-r--r-- | include/linux/i2c.h | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 5ac0f9055715..5d7f3c1853ae 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -81,6 +81,22 @@ static inline int i2c_master_recv(const struct i2c_client *client, }; /** + * 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 @@ 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, |