i2c: Clarify behavior of I2C_M_RD flag

CraftyChimera · Wolfram Sang · commit c3ff7f06c787 · 2025-07-14T09:15:58.000+02:00
Update the description of I2C_M_RD to clarify that not setting it
signals a write transaction

Signed-off-by: I Viswanath &lt;viswanathiyyappan@gmail.com&gt;
Signed-off-by: Wolfram Sang &lt;wsa+renesas@sang-engineering.com&gt;
diff --git a/include/uapi/linux/i2c.h b/include/uapi/linux/i2c.h
@@ -21,7 +21,8 @@
  *
  * @flags:
  *   Supported by all adapters:
- *   %I2C_M_RD: read data (from slave to master). Guaranteed to be 0x0001!
+ *   %I2C_M_RD: read data (from slave to master). Guaranteed to be 0x0001! If
+ *   not set, the transaction is interpreted as write.
  *
  *   Optional:
  *   %I2C_M_DMA_SAFE: the buffer of this message is DMA safe. Makes only sense

Original file line number	Diff line number	Diff line change
`@@ -21,7 +21,8 @@`
`21`	`21`	`*`
`22`	`22`	`* @flags:`
`23`	`23`	`* Supported by all adapters:`
`24`		`- * %I2C_M_RD: read data (from slave to master). Guaranteed to be 0x0001!`
	`24`	`+ * %I2C_M_RD: read data (from slave to master). Guaranteed to be 0x0001! If`
	`25`	`+ * not set, the transaction is interpreted as write.`
`25`	`26`	`*`
`26`	`27`	`* Optional:`
`27`	`28`	`* %I2C_M_DMA_SAFE: the buffer of this message is DMA safe. Makes only sense`