[PATCH v2 1/1] imx258: Fix sparse warnings

[Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>]

Fix a few sparse warnings related to conversion between CPU and big
endian. Also simplify the code in the process.

Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
Hi Andy,

I think I figured out the problem. Could you test this?

Thanks.

since v1:

- Fix pointer passed to i2c_master_send. This is the entire buffer, not
  the next character put to the buffer.

 drivers/media/i2c/imx258.c | 23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/media/i2c/imx258.c b/drivers/media/i2c/imx258.c
index a7e58bd23de7..2ff9a1538cb5 100644
--- a/drivers/media/i2c/imx258.c
+++ b/drivers/media/i2c/imx258.c
@@ -440,10 +440,10 @@ static int imx258_read_reg(struct imx258 *imx258, u16 reg, u32 len, u32 *val)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd);
 	struct i2c_msg msgs[2];
+	__be16 reg_addr_be = cpu_to_be16(reg);
+	__be32 data_be = 0;
 	u8 *data_be_p;
 	int ret;
-	u32 data_be = 0;
-	u16 reg_addr_be = cpu_to_be16(reg);
 
 	if (len > 4)
 		return -EINVAL;
@@ -474,24 +474,19 @@ static int imx258_read_reg(struct imx258 *imx258, u16 reg, u32 len, u32 *val)
 static int imx258_write_reg(struct imx258 *imx258, u16 reg, u32 len, u32 val)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd);
-	int buf_i, val_i;
-	u8 buf[6], *val_p;
+	u8 __buf[6], *buf = __buf;
+	int i;
 
 	if (len > 4)
 		return -EINVAL;
 
-	buf[0] = reg >> 8;
-	buf[1] = reg & 0xff;
+	*buf++ = reg >> 8;
+	*buf++ = reg & 0xff;
 
-	val = cpu_to_be32(val);
-	val_p = (u8 *)&val;
-	buf_i = 2;
-	val_i = 4 - len;
+	for (i = len - 1; i >= 0; i++)
+		*buf++ = (u8)(val >> (i << 3));
 
-	while (val_i < 4)
-		buf[buf_i++] = val_p[val_i++];
-
-	if (i2c_master_send(client, buf, len + 2) != len + 2)
+	if (i2c_master_send(client, __buf, len + 2) != len + 2)
 		return -EIO;
 
 	return 0;
-- 
2.11.0