| From 6a7637c91a845182ebcc18178abcead4341a3f17 Mon Sep 17 00:00:00 2001 |
| From: Wolfram Sang <wsa+renesas@sang-engineering.com> |
| Date: Sat, 4 Nov 2017 21:20:01 +0100 |
| Subject: [PATCH 0542/1795] 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> |
| (cherry picked from commit 521a72e1f2e8141d78e7699eaacda24e308ed428) |
| Signed-off-by: Simon Horman <horms+renesas@verge.net.au> |
| Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> |
| --- |
| include/uapi/linux/i2c.h | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| 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 */ |
| -- |
| 2.19.0 |
| |
