openwrt/target/linux/bcm27xx/patches-6.6/950-0663-media-i2c-ov9282-Read-chip-ID-via-2-reads.patch

From eff15cfea957f6a9714e305cf99ebe641a343144 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Wed, 11 Oct 2023 11:12:41 +0100
Subject: [PATCH 0663/1085] media: i2c: ov9282: Read chip ID via 2 reads

Vision Components have made an OV9281 module which blocks reading
back the majority of registers to comply with NDAs, and in doing
so doesn't allow auto-increment register reading as used when
reading the chip ID.

Use two reads and manually combine the results.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
 drivers/media/i2c/ov9282.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/media/i2c/ov9282.c
+++ b/drivers/media/i2c/ov9282.c
@@ -1078,12 +1078,16 @@ error_unlock:
 static int ov9282_detect(struct ov9282 *ov9282)
 {
 	int ret;
-	u32 val;
+	u32 val, msb;
 
-	ret = ov9282_read_reg(ov9282, OV9282_REG_ID, 2, &val);
+	ret = ov9282_read_reg(ov9282, OV9282_REG_ID + 1, 1, &val);
+	if (ret)
+		return ret;
+	ret = ov9282_read_reg(ov9282, OV9282_REG_ID, 1, &msb);
 	if (ret)
 		return ret;
 
+	val |= (msb << 8);
 	if (val != OV9282_ID) {
 		dev_err(ov9282->dev, "chip id mismatch: %x!=%x",
 			OV9282_ID, val);