[PATCH v5 08/15] media: i2c: rdacm21: Add delay after OV490 reset

From: Jacopo Mondi
Date: Wed Jun 16 2021 - 08:46:14 EST


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 <jacopo+renesas@xxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
---
drivers/media/i2c/rdacm21.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c
index 553e3f03752b..6be8ce130e78 100644
--- a/drivers/media/i2c/rdacm21.c
+++ b/drivers/media/i2c/rdacm21.c
@@ -469,7 +469,10 @@ 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;
@@ -477,6 +480,7 @@ static int rdacm21_initialize(struct rdacm21_device *dev)
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)
--
2.31.1