From: Jacopo Mondi <jacopo@jmondi.org>
To: Roman Kovalivskyi <roman.kovalivskyi@globallogic.com>
Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
linux-renesas-soc@vger.kernel.org,
"Luis Oliveira" <lolivei@synopsys.com>,
"Niklas Söderlund" <niklas.soderlund@ragnatech.se>,
"Michael Rodin" <mrodin@de.adit-jv.com>,
"Mauro Carvalho Chehab" <mchehab@kernel.org>,
"Sakari Ailus" <sakari.ailus@linux.intel.com>,
"Hugues Fruchet" <hugues.fruchet@st.com>,
"Maxime Ripard" <mripard@kernel.org>,
"Adam Ford" <aford173@gmail.com>,
"Todor Tomov" <todor.tomov@linaro.org>,
"Suresh Udipi" <sudipi@jp.adit-jv.com>,
"Andrew Gabbasov" <andrew_gabbasov@mentor.com>,
"Eugeniu Rosca" <erosca@de.adit-jv.com>,
"Dave Stevenson" <dave.stevenson@raspberrypi.org>
Subject: Re: [PATCH 2/4] media: ov5647: Add support for PWDN GPIO.
Date: Wed, 15 Apr 2020 14:38:42 +0200 [thread overview]
Message-ID: <20200415123842.wiu5vs5lilxvqg7x@uno.localdomain> (raw)
In-Reply-To: <f88b99899eb5e680607349b37eb3679dbd12433e.1586759968.git.roman.kovalivskyi@globallogic.com>
Hi Roman,
this patch requires the device bindings document to be updated
to report an optional 'powerdown-gpios' property is available and that
it's active HIGH.
On Mon, Apr 13, 2020 at 12:17:45PM +0300, Roman Kovalivskyi wrote:
> From: Dave Stevenson <dave.stevenson@raspberrypi.org>
>
> Add support for an optional GPIO connected to PWDN on the sensor. This
> allows the use of hardware standby mode where internal device clock
> and circuit activities are halted.
>
> Please nothe that power is off when PWDN is high.
>
> Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
> Signed-off-by: Roman Kovalivskyi <roman.kovalivskyi@globallogic.com>
> ---
> drivers/media/i2c/ov5647.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/drivers/media/i2c/ov5647.c b/drivers/media/i2c/ov5647.c
> index 3e587eb0a30e..c39e3d20e3ef 100644
> --- a/drivers/media/i2c/ov5647.c
> +++ b/drivers/media/i2c/ov5647.c
> @@ -21,6 +21,7 @@
>
> #include <linux/clk.h>
> #include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> #include <linux/i2c.h>
> #include <linux/init.h>
> #include <linux/io.h>
> @@ -35,6 +36,13 @@
>
> #define SENSOR_NAME "ov5647"
>
> +/*
> + * From the datasheet, "20ms after PWDN goes low or 20ms after RESETB goes
> + * high if reset is inserted after PWDN goes high, host can access sensor's
> + * SCCB to initialize sensor."
> + */
> +#define PWDN_ACTIVE_DELAY_MS 20
> +
> #define MIPI_CTRL00_CLOCK_LANE_GATE BIT(5)
> #define MIPI_CTRL00_BUS_IDLE BIT(2)
> #define MIPI_CTRL00_CLOCK_LANE_DISABLE BIT(0)
> @@ -86,6 +94,7 @@ struct ov5647 {
> unsigned int height;
> int power_count;
> struct clk *xclk;
> + struct gpio_desc *pwdn;
> };
>
> static inline struct ov5647 *to_state(struct v4l2_subdev *sd)
> @@ -355,6 +364,11 @@ static int ov5647_sensor_power(struct v4l2_subdev *sd, int on)
> if (on && !ov5647->power_count) {
> dev_dbg(&client->dev, "OV5647 power on\n");
>
> + if (ov5647->pwdn) {
> + gpiod_set_value(ov5647->pwdn, 0);
> + msleep(PWDN_ACTIVE_DELAY_MS);
please use usleep_range() according to Documentation/timers/timers-howto.rst
Thanks
j
> + }
> +
> ret = clk_prepare_enable(ov5647->xclk);
> if (ret < 0) {
> dev_err(&client->dev, "clk prepare enable failed\n");
> @@ -392,6 +406,8 @@ static int ov5647_sensor_power(struct v4l2_subdev *sd, int on)
> dev_dbg(&client->dev, "soft stby failed\n");
>
> clk_disable_unprepare(ov5647->xclk);
> +
> + gpiod_set_value(ov5647->pwdn, 1);
> }
>
> /* Update the power count. */
> @@ -603,6 +619,10 @@ static int ov5647_probe(struct i2c_client *client)
> return -EINVAL;
> }
>
> + /* Request the power down GPIO asserted */
> + sensor->pwdn = devm_gpiod_get_optional(&client->dev, "pwdn",
> + GPIOD_OUT_HIGH);
> +
> mutex_init(&sensor->lock);
>
> sd = &sensor->sd;
> @@ -616,7 +636,15 @@ static int ov5647_probe(struct i2c_client *client)
> if (ret < 0)
> goto mutex_remove;
>
> + if (sensor->pwdn) {
> + gpiod_set_value(sensor->pwdn, 0);
> + msleep(PWDN_ACTIVE_DELAY_MS);
> + }
> +
> ret = ov5647_detect(sd);
> +
> + gpiod_set_value(sensor->pwdn, 1);
> +
> if (ret < 0)
> goto error;
>
> --
> 2.17.1
>
next prev parent reply other threads:[~2020-04-15 12:36 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-13 9:17 [PATCH 0/4] ov5647 driver improvement Roman Kovalivskyi
[not found] ` <cover.1586759968.git.roman.kovalivskyi@globallogic.com>
2020-04-13 9:17 ` [PATCH 1/4] media: ov5647: Add set_fmt and get_fmt calls Roman Kovalivskyi
2020-04-15 12:11 ` Jacopo Mondi
2020-04-13 9:17 ` [PATCH 2/4] media: ov5647: Add support for PWDN GPIO Roman Kovalivskyi
2020-04-15 12:38 ` Jacopo Mondi [this message]
2020-04-13 9:17 ` [PATCH 3/4] media: ov5647: Add support for non-continuous clock mode Roman Kovalivskyi
2020-04-15 13:17 ` Jacopo Mondi
2020-04-23 7:47 ` Sakari Ailus
2020-04-13 9:17 ` [PATCH 4/4] media: ov5647: Use gpiod_set_value_cansleep Roman Kovalivskyi
2020-04-23 7:55 ` Sakari Ailus
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