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| author | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2017-11-04 21:20:01 +0100 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2017-12-03 20:47:33 +0100 |
| commit | 521a72e1f2e8141d78e7699eaacda24e308ed428 (patch) | |
| tree | 11ef5aef08fb208c3152812c36ecb5bedfa95dd1 /include | |
| parent | 14911c6f48ec9571343ac36ae02f2db68bf9e7f9 (diff) | |
| download | linux-521a72e1f2e8141d78e7699eaacda24e308ed428.tar.gz linux-521a72e1f2e8141d78e7699eaacda24e308ed428.tar.bz2 linux-521a72e1f2e8141d78e7699eaacda24e308ed428.zip | |
i2c: add a message flag for DMA safe buffers
I2C has no requirement that the buffer of a message needs to be DMA
safe. In case it is, it can now be flagged, so drivers wishing to
do DMA can use the buffer directly.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'include')
| -rw-r--r-- | include/uapi/linux/i2c.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/uapi/linux/i2c.h b/include/uapi/linux/i2c.h index fe648032d6b9..f71a1751cacf 100644 --- a/include/uapi/linux/i2c.h +++ b/include/uapi/linux/i2c.h @@ -72,6 +72,9 @@ struct i2c_msg { #define I2C_M_RD 0x0001 /* read data, from slave to master */ /* I2C_M_RD is guaranteed to be 0x0001! */ #define I2C_M_TEN 0x0010 /* this is a ten bit chip address */ +#define I2C_M_DMA_SAFE 0x0200 /* the buffer of this message is DMA safe */ + /* makes only sense in kernelspace */ + /* userspace buffers are copied anyway */ #define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */ #define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */ #define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */ |