GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-07-20 05:43:09 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

i2c: add helpers to ease DMA handling

Browse source 
One helper checks if DMA is suitable and optionally creates a bounce
buffer, if not. The other function returns the bounce buffer and makes
sure the data is properly copied back to the message.

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>
This commit is contained in:
Wolfram Sang 2017-11-04 21:20:02 +01:00 • committed by Wolfram Sang
parent 521a72e1f2
commit e94bc5d18b
2 changed files with 49 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

3
include/linux/i2c.h
View file

@ -768,6 +768,9 @@ static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
}
u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
void i2c_release_dma_safe_msg_buf(struct i2c_msg *msg, u8 *buf);
int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
/**
* module_i2c_driver() - Helper macro for registering a modular I2C driver