i3c: Remove the const qualifier from i2c_msg pointer in i2c_xfers API

The change is necessary to enable the use of the
`i2c_get_dma_safe_msg_buf()` API, which requires a non-const
`struct i2c_msg *` to operate. The `i2c_get_dma_safe_msg_buf()` function
ensures safe handling of I2C messages when using DMA, making it essential
for scenarios where DMA transfers are involved. By removing the `const`
qualifier, this patch allows drivers to prepare and manage DMA-safe
buffers directly.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com>
Link: https://lore.kernel.org/r/20250204091702.4014466-1-billy_tsai@aspeedtech.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: billy-tsai

drivers/i3c/master/dw-i3c-master.c

@@ -1079,7 +1079,7 @@ static void dw_i3c_master_detach_i3c_dev(struct i3c_dev_desc *dev)
 }
 
 static int dw_i3c_master_i2c_xfers(struct i2c_dev_desc *dev,
-				   const struct i2c_msg *i2c_xfers,
+				   struct i2c_msg *i2c_xfers,
 				   int i2c_nxfers)
 {
 	struct dw_i3c_i2c_dev_data *data = i2c_dev_get_master_data(dev);

drivers/i3c/master/i3c-master-cdns.c

@@ -813,7 +813,7 @@ static int cdns_i3c_master_priv_xfers(struct i3c_dev_desc *dev,
 }
 
 static int cdns_i3c_master_i2c_xfers(struct i2c_dev_desc *dev,
-				     const struct i2c_msg *xfers, int nxfers)
+				     struct i2c_msg *xfers, int nxfers)
 {
 	struct i3c_master_controller *m = i2c_dev_get_master(dev);
 	struct cdns_i3c_master *master = to_cdns_i3c_master(m);

drivers/i3c/master/mipi-i3c-hci/core.c

@@ -367,7 +367,7 @@ static int i3c_hci_priv_xfers(struct i3c_dev_desc *dev,
 }
 
 static int i3c_hci_i2c_xfers(struct i2c_dev_desc *dev,
-			     const struct i2c_msg *i2c_xfers, int nxfers)
+			     struct i2c_msg *i2c_xfers, int nxfers)
 {
 	struct i3c_master_controller *m = i2c_dev_get_master(dev);
 	struct i3c_hci *hci = to_i3c_hci(m);

drivers/i3c/master/svc-i3c-master.c

@@ -1584,7 +1584,7 @@ static int svc_i3c_master_priv_xfers(struct i3c_dev_desc *dev,
 }
 
 static int svc_i3c_master_i2c_xfers(struct i2c_dev_desc *dev,
-				    const struct i2c_msg *xfers,
+				    struct i2c_msg *xfers,
 				    int nxfers)
 {
 	struct i3c_master_controller *m = i2c_dev_get_master(dev);

include/linux/i3c/master.h

@@ -475,7 +475,7 @@ struct i3c_master_controller_ops {
 	int (*attach_i2c_dev)(struct i2c_dev_desc *dev);
 	void (*detach_i2c_dev)(struct i2c_dev_desc *dev);
 	int (*i2c_xfers)(struct i2c_dev_desc *dev,
-			 const struct i2c_msg *xfers, int nxfers);
+			 struct i2c_msg *xfers, int nxfers);
 	int (*request_ibi)(struct i3c_dev_desc *dev,
 			   const struct i3c_ibi_setup *req);
 	void (*free_ibi)(struct i3c_dev_desc *dev);