From e94bc5d18be03dac8e9d73d30c5523728edeff76 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Sat, 4 Nov 2017 21:20:02 +0100 Subject: i2c: add helpers to ease DMA handling 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 Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang --- include/linux/i2c.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/i2c.h') diff --git a/include/linux/i2c.h b/include/linux/i2c.h index a556db976fc6..9d9d379b5a15 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -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 -- cgit v1.2.3