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 <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index a556db9..9d9d379b 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