media: i2c: rdacm21: Add delay after OV490 reset

Add a delay after the OV490 chip is put in reset state. The reset
signal shall be held low for at least 250 useconds.

Signed-off-by: Jacopo Mondi <[email protected]>
Reviewed-by: Laurent Pinchart <[email protected]>
Reviewed-by: Kieran Bingham <[email protected]>
Signed-off-by: Hans Verkuil <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>

Author: Jacopo Mondi

drivers/media/i2c/rdacm21.c

@@ -469,14 +469,18 @@ static int rdacm21_initialize(struct rdacm21_device *dev)
 	if (ret)
 		return ret;
 
-	/* Enable GPIO1 and hold OV490 in reset during max9271 configuration. */
+	/*
+	 * Enable GPIO1 and hold OV490 in reset during max9271 configuration.
+	 * The reset signal has to be asserted for at least 250 useconds.
+	 */
 	ret = max9271_enable_gpios(&dev->serializer, MAX9271_GPIO1OUT);
 	if (ret)
 		return ret;
 
 	ret = max9271_clear_gpios(&dev->serializer, MAX9271_GPIO1OUT);
 	if (ret)
 		return ret;
+	usleep_range(250, 500);
 
 	ret = max9271_configure_gmsl_link(&dev->serializer);
 	if (ret)