From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To: Andrey Konovalov <andrey.konovalov@linaro.org>
Cc: mchehab@kernel.org, sakari.ailus@iki.fi,
linux-media@vger.kernel.org, peter.griffin@linaro.org
Subject: Re: [PATCH 3/3] media: i2c: imx290: fix reset GPIO pin handling
Date: Tue, 3 Mar 2020 17:03:16 +0530 [thread overview]
Message-ID: <20200303113316.GC16981@mani> (raw)
In-Reply-To: <20200226215913.10631-4-andrey.konovalov@linaro.org>
On Thu, Feb 27, 2020 at 12:59:13AM +0300, Andrey Konovalov wrote:
> According to https://www.kernel.org/doc/Documentation/gpio/consumer.txt,
>
> - all of the gpiod_set_value_xxx() functions operate with the *logical* value.
> So in imx290_power_on() the reset signal should be cleared/de-asserted with
> gpiod_set_value_cansleep(imx290->rst_gpio, 0), and in imx290_power_off() the
> value of 1 must be used to apply/assert the reset to the sensor. In the device
> tree the reset pin is described as GPIO_ACTIVE_LOW, and gpiod_set_value_xxx()
> functions take this into account,
>
> - when devm_gpiod_get_optional() is called with GPIOD_ASIS, the GPIO is not
> initialized, and the direction must be set later; using a GPIO
> without setting its direction first is illegal and will result in undefined
> behavior. Fix this by using GPIOD_OUT_HIGH instead of GPIOD_ASIS (this asserts
> the reset signal to the sensor initially).
>
I didn't catch this issue since I've been using IMX290 board on top of Sensors
mezzanine which has the pullup on that pin. But this fix LGTM.
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Thanks,
Mani
> Signed-off-by: Andrey Konovalov <andrey.konovalov@linaro.org>
> ---
> drivers/media/i2c/imx290.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/i2c/imx290.c b/drivers/media/i2c/imx290.c
> index d0322f9a8856..7b1de1f0c8b7 100644
> --- a/drivers/media/i2c/imx290.c
> +++ b/drivers/media/i2c/imx290.c
> @@ -628,7 +628,7 @@ static int imx290_power_on(struct device *dev)
> }
>
> usleep_range(1, 2);
> - gpiod_set_value_cansleep(imx290->rst_gpio, 1);
> + gpiod_set_value_cansleep(imx290->rst_gpio, 0);
> usleep_range(30000, 31000);
>
> return 0;
> @@ -641,7 +641,7 @@ static int imx290_power_off(struct device *dev)
> struct imx290 *imx290 = to_imx290(sd);
>
> clk_disable_unprepare(imx290->xclk);
> - gpiod_set_value_cansleep(imx290->rst_gpio, 0);
> + gpiod_set_value_cansleep(imx290->rst_gpio, 1);
> regulator_bulk_disable(IMX290_NUM_SUPPLIES, imx290->supplies);
>
> return 0;
> @@ -757,7 +757,8 @@ static int imx290_probe(struct i2c_client *client)
> goto free_err;
> }
>
> - imx290->rst_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_ASIS);
> + imx290->rst_gpio = devm_gpiod_get_optional(dev, "reset",
> + GPIOD_OUT_HIGH);
> if (IS_ERR(imx290->rst_gpio)) {
> dev_err(dev, "Cannot get reset gpio\n");
> ret = PTR_ERR(imx290->rst_gpio);
> --
> 2.17.1
>
next prev parent reply other threads:[~2020-03-03 11:33 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-26 21:59 [PATCH 0/3] IMX290 sensor driver fixes Andrey Konovalov
2020-02-26 21:59 ` [PATCH 1/3] media: i2c: imx290: set the format before VIDIOC_SUBDEV_G_FMT is called Andrey Konovalov
2020-03-03 9:30 ` Manivannan Sadhasivam
2020-02-26 21:59 ` [PATCH 2/3] media: i2c: imx290: fix the order of the args in SET_RUNTIME_PM_OPS() Andrey Konovalov
2020-03-03 9:39 ` Manivannan Sadhasivam
2020-02-26 21:59 ` [PATCH 3/3] media: i2c: imx290: fix reset GPIO pin handling Andrey Konovalov
2020-03-03 11:33 ` Manivannan Sadhasivam [this message]
2020-04-07 8:19 ` [PATCH 0/3] IMX290 sensor driver fixes Manivannan Sadhasivam
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