[PATCH v2 12/21] media: i2c: it6625: use unaligned/units helpers to decode pixel clock

[Hermes Wu via B4 Relay <devnull+Hermes.wu.ite.com.tw@kernel.org>]

From: Hermes Wu <Hermes.wu@ite.com.tw>

it6625_get_pclk() manually assembled a big-endian u32 from a 4-byte
buffer with a shift-and-OR sequence, and multiplied by a bare 1000.
Read the register range with sizeof(ck), decode it with
get_unaligned_be32(), and use HZ_PER_KHZ to convert the kHz register
value to the Hz value V4L2 DV timings expect. Add the linux/unaligned.h
and linux/units.h includes these need. While touching this declaration
block, reorder it per reverse fir-tree.

Signed-off-by: Hermes Wu <Hermes.wu@ite.com.tw>
---
 drivers/media/i2c/it6625.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/media/i2c/it6625.c b/drivers/media/i2c/it6625.c
index b72b1fdc8f6b96c807bf767b82a953a89b08120a..f77eb3ed63f7695cf9da277b46d9bab4a526e065 100644
--- a/drivers/media/i2c/it6625.c
+++ b/drivers/media/i2c/it6625.c
@@ -18,6 +18,8 @@
 #include <linux/slab.h>
 #include <linux/time64.h>
 #include <linux/timer.h>
+#include <linux/unaligned.h>
+#include <linux/units.h>
 #include <linux/v4l2-dv-timings.h>
 #include <linux/videodev2.h>
 #include <linux/workqueue.h>
@@ -633,28 +635,22 @@ static int get_audio_sampling_rate(struct it6625 *it6625)
 
 static u64 it6625_get_pclk(struct it6625 *it6625)
 {
-	u32 pclk;
 	u8 ck[4];
+	u32 pclk;
 	int ret;
 
-	ret = it6625_read_bytes(it6625, REG_VID_PCLK, ck, 4);
+	ret = it6625_read_bytes(it6625, REG_VID_PCLK, ck, sizeof(ck));
 	if (ret < 0) {
 		dev_err(it6625->dev, "failed to read pixel clock");
 		return 0;
 	}
 
-	pclk = ck[0];
-	pclk <<= 8;
-	pclk |= ck[1];
-	pclk <<= 8;
-	pclk |= ck[2];
-	pclk <<= 8;
-	pclk |= ck[3];
+	pclk = get_unaligned_be32(ck);
 
 	v4l2_dbg(1, debug, &it6625->sd, "%s: pclk=%u (%08x)",
 		 __func__, pclk, pclk);
 
-	return (u64)pclk * 1000;
+	return (u64)pclk * HZ_PER_KHZ;
 }
 
 static int it6625_read_edid(struct it6625 *it6625, u8 *edid, int start_block,

-- 
2.34.1