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From:   Jacopo Mondi <jacopo+renesas@jmondi.org>
To:     kieran.bingham+renesas@ideasonboard.com,
        laurent.pinchart+renesas@ideasonboard.com,
        niklas.soderlund+renesas@ragnatech.se, geert@linux-m68k.org
Cc:     Jacopo Mondi <jacopo+renesas@jmondi.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v4 08/17] media: i2c: rdacm21: Add dealy after OV490 reset
Date:   Mon, 12 Apr 2021 11:34:42 +0200
Message-Id: <20210412093451.14198-9-jacopo+renesas@jmondi.org>
In-Reply-To: <20210412093451.14198-1-jacopo+renesas@jmondi.org>
References: <20210412093451.14198-1-jacopo+renesas@jmondi.org>
MIME-Version: 1.0
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Add a delay after the OV490 chip is put in reset state. The reset
signal shall be held for at least 250 useconds.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
 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