From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Jacopo Mondi <jacopo+renesas@jmondi.org>
Cc: kieran.bingham+renesas@ideasonboard.com,
niklas.soderlund+renesas@ragnatech.se, geert@linux-m68k.org,
Mauro Carvalho Chehab <mchehab@kernel.org>,
linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 06/16] media: i2c: rdacm20: Re-work ov10635 reset
Date: Mon, 22 Feb 2021 03:15:36 +0200 [thread overview]
Message-ID: <YDMFuJ/SJ2wJstHe@pendragon.ideasonboard.com> (raw)
In-Reply-To: <20210216174146.106639-7-jacopo+renesas@jmondi.org>
Hi Jacopo,
Thank you for the patch.
On Tue, Feb 16, 2021 at 06:41:36PM +0100, Jacopo Mondi wrote:
> The OV10635 image sensor embedded in the camera module is currently
> reset after the MAX9271 initialization with two long delays that were
> most probably not correctly characterized.
>
> Re-work the image sensor reset procedure by holding the chip in reset
> during the MAX9271 configuration, removing the long sleep delays and
> only wait after the chip exits from reset for 350-500 microseconds
> interval, which is larger than the minimum (2048 * (1 / XVCLK)) timeout
> characterized in the chip manual.
>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> ---
> drivers/media/i2c/rdacm20.c | 25 +++++++++++--------------
> 1 file changed, 11 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/media/i2c/rdacm20.c b/drivers/media/i2c/rdacm20.c
> index e982373908f2..ea30cc936531 100644
> --- a/drivers/media/i2c/rdacm20.c
> +++ b/drivers/media/i2c/rdacm20.c
> @@ -477,6 +477,15 @@ static int rdacm20_initialize(struct rdacm20_device *dev)
> if (ret)
> return ret;
>
> + /* Hold OV10635 in reset during max9271 configuration. */
> + ret = max9271_enable_gpios(&dev->serializer, MAX9271_GPIO1OUT);
> + if (ret)
> + return ret;
> +
> + ret = max9271_clear_gpios(&dev->serializer, MAX9271_GPIO1OUT);
> + if (ret)
> + return ret;
> +
Unrelated to this patch, it could be nice to rename the GPIO-related
functions to use a similar naming scheme as the gpiod API.
> ret = max9271_configure_gmsl_link(&dev->serializer);
> if (ret)
> return ret;
> @@ -490,23 +499,11 @@ static int rdacm20_initialize(struct rdacm20_device *dev)
> return ret;
> dev->serializer.client->addr = dev->addrs[0];
>
> - /*
> - * Reset the sensor by cycling the OV10635 reset signal connected to the
> - * MAX9271 GPIO1 and verify communication with the OV10635.
> - */
> - 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(10000, 15000);
The OV10635 requires the reset signal to be asserted for at least 200µs.
Is this guaranteed by the different calls we have here after asserting
reset ? Maybe a comment to explain this could be useful ?
> -
> + /* Release ov10635 from reset and initialize it. */
> ret = max9271_set_gpios(&dev->serializer, MAX9271_GPIO1OUT);
> if (ret)
> return ret;
> - usleep_range(10000, 15000);
Maybe a comment here to state that the delay has to be at least 2048
XVCLK cycles would be useful ?
With these taken into account,
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> + usleep_range(350, 500);
>
> for (i = 0; i < OV10635_PID_TIMEOUT; ++i) {
> ret = ov10635_read16(dev, OV10635_PID);
--
Regards,
Laurent Pinchart
next prev parent reply other threads:[~2021-02-22 1:17 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-16 17:41 [PATCH 00/16] media: i2c: GMSL reliability improvements Jacopo Mondi
2021-02-16 17:41 ` [PATCH 01/16] media: i2c: rdacm20: Enable noise immunity Jacopo Mondi
2021-02-17 12:55 ` Kieran Bingham
2021-02-22 0:49 ` Laurent Pinchart
2021-02-22 14:59 ` Jacopo Mondi
2021-02-24 20:35 ` Laurent Pinchart
2021-02-16 17:41 ` [PATCH 02/16] media: i2c: rdacm20: Embedded 'serializer' field Jacopo Mondi
2021-02-17 12:56 ` Kieran Bingham
2021-02-22 0:58 ` Laurent Pinchart
2021-02-16 17:41 ` [PATCH 03/16] media: i2c: rdacm20: Replace goto with a loop Jacopo Mondi
2021-02-17 13:01 ` Kieran Bingham
2021-02-22 1:05 ` Laurent Pinchart
2021-02-22 15:06 ` Jacopo Mondi
2021-02-24 20:27 ` Laurent Pinchart
2021-02-25 8:56 ` Kieran Bingham
2021-02-16 17:41 ` [PATCH 04/16] media: i2c: rdacm20: Report camera module name Jacopo Mondi
2021-02-17 13:02 ` Kieran Bingham
2021-02-22 1:06 ` Laurent Pinchart
2021-02-16 17:41 ` [PATCH 05/16] media: i2c: rdacm20: Check return values Jacopo Mondi
2021-02-17 13:08 ` Kieran Bingham
2021-02-22 1:09 ` Laurent Pinchart
2021-02-22 15:08 ` Jacopo Mondi
2021-02-16 17:41 ` [PATCH 06/16] media: i2c: rdacm20: Re-work ov10635 reset Jacopo Mondi
2021-02-17 13:22 ` Kieran Bingham
2021-02-22 1:15 ` Laurent Pinchart [this message]
2021-02-16 17:41 ` [PATCH 07/16] media: i2c: rdacm2x: Fix wake up delay Jacopo Mondi
2021-02-17 8:02 ` Geert Uytterhoeven
2021-02-17 13:33 ` Kieran Bingham
2021-02-22 1:18 ` Laurent Pinchart
2021-02-22 15:11 ` Jacopo Mondi
2021-02-24 20:29 ` Laurent Pinchart
2021-02-16 17:41 ` [PATCH 08/16] media: i2c: max9286: Adjust parameters indent Jacopo Mondi
2021-02-17 13:36 ` Kieran Bingham
2021-02-22 1:20 ` Laurent Pinchart
2021-02-16 17:41 ` [PATCH 09/16] media: i2c: rdacm21: Re-work OV10640 initialization Jacopo Mondi
2021-02-17 8:06 ` Geert Uytterhoeven
2021-02-17 13:55 ` Kieran Bingham
2021-02-22 1:27 ` Laurent Pinchart
2021-02-22 15:19 ` Jacopo Mondi
2021-02-24 20:30 ` Laurent Pinchart
2021-02-16 17:41 ` [PATCH 10/16] media: i2c: max9286: Rename reverse_channel_mv Jacopo Mondi
2021-02-17 8:07 ` Geert Uytterhoeven
2021-02-18 15:06 ` Kieran Bingham
2021-02-22 1:29 ` Laurent Pinchart
2021-02-16 17:41 ` [PATCH 11/16] media: i2c: max9286: Cache channel amplitude Jacopo Mondi
2021-02-17 8:08 ` Geert Uytterhoeven
2021-02-18 15:39 ` Kieran Bingham
2021-02-22 1:33 ` Laurent Pinchart
2021-02-16 17:41 ` [PATCH 12/16] media: i2c: max9286: Define high " Jacopo Mondi
2021-02-18 15:39 ` Kieran Bingham
2021-02-22 1:35 ` Laurent Pinchart
2021-02-16 17:41 ` [PATCH 13/16] media: i2c: rdacm2x: Implement .init() subdev op Jacopo Mondi
2021-02-17 8:17 ` Geert Uytterhoeven
2021-02-18 16:13 ` Kieran Bingham
2021-02-22 1:52 ` Laurent Pinchart
2021-02-16 17:41 ` [PATCH 14/16] media: i2c: max9286: Initialize remotes when bound Jacopo Mondi
2021-02-17 8:19 ` Geert Uytterhoeven
2021-02-18 16:00 ` Kieran Bingham
2021-02-22 2:03 ` Laurent Pinchart
2021-02-16 17:41 ` [PATCH 15/16] media: i2c: max9286: Rework comments in .bound() Jacopo Mondi
2021-02-18 16:03 ` Kieran Bingham
2021-02-16 17:41 ` [PATCH 16/16] media: i2c: gmsl: Use 339Kbps I2C bit-rate Jacopo Mondi
2021-02-17 8:19 ` Geert Uytterhoeven
2021-02-18 16:07 ` Kieran Bingham
2021-02-22 2:06 ` Laurent Pinchart
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