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Message-ID: <20190920101706.GX5781@paasikivi.fi.intel.com>
Date: Fri, 20 Sep 2019 13:17:06 +0300
From: Sakari Ailus <sakari.ailus@...ux.intel.com>
To: Benoit Parrot <bparrot@...com>
Cc: Hans Verkuil <hverkuil@...all.nl>,
Prabhakar Lad <prabhakar.csengg@...il.com>,
linux-media@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [Patch v2 5/7] media: i2c: ov2659: Add powerdown/reset gpio
handling
Hi Benoit,
Thanks for the update.
On Thu, Sep 19, 2019 at 03:39:53PM -0500, Benoit Parrot wrote:
> On some board it is possible that the sensor 'powerdown' and or 'reset'
> pin might be controlled by gpio instead of being tied.
>
> To implement we add pm_runtime support which will handle the power
> up/down sequence.
>
> Now originally the driver assumed tat the sensor would always stay
> powered and there keep its register setting. We cannot assume that this
> anymore, so every time we "power up" we need to re-program the initial
> registers configuration first. This was previously done only at probe
> time.
>
> Signed-off-by: Benoit Parrot <bparrot@...com>
> ---
> drivers/media/i2c/Kconfig | 2 +-
> drivers/media/i2c/ov2659.c | 88 +++++++++++++++++++++++++++++++++++++-
> 2 files changed, 88 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 7eee1812bba3..315c1d8bdb7b 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -634,7 +634,7 @@ config VIDEO_OV2640
> config VIDEO_OV2659
> tristate "OmniVision OV2659 sensor support"
> depends on VIDEO_V4L2 && I2C
> - depends on MEDIA_CAMERA_SUPPORT
> + depends on MEDIA_CAMERA_SUPPORT && GPIOLIB
> select V4L2_FWNODE
> help
> This is a Video4Linux2 sensor driver for the OmniVision
> diff --git a/drivers/media/i2c/ov2659.c b/drivers/media/i2c/ov2659.c
> index f77320e8a60d..170f80a1a51f 100644
> --- a/drivers/media/i2c/ov2659.c
> +++ b/drivers/media/i2c/ov2659.c
> @@ -22,9 +22,11 @@
>
> #include <linux/clk.h>
> #include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> #include <linux/i2c.h>
> #include <linux/module.h>
> #include <linux/of_graph.h>
> +#include <linux/pm_runtime.h>
>
> #include <media/i2c/ov2659.h>
> #include <media/v4l2-ctrls.h>
> @@ -218,6 +220,11 @@ struct ov2659 {
> struct sensor_register *format_ctrl_regs;
> struct ov2659_pll_ctrl pll;
> int streaming;
> + /* used to control the sensor PWDN pin */
> + struct gpio_desc *pwdn_gpio;
> + /* used to control the sensor RESETB pin */
> + struct gpio_desc *resetb_gpio;
> + int on;
> };
>
> static const struct sensor_register ov2659_init_regs[] = {
> @@ -1184,9 +1191,17 @@ static int ov2659_s_stream(struct v4l2_subdev *sd, int on)
> /* Stop Streaming Sequence */
> ov2659_set_streaming(ov2659, 0);
> ov2659->streaming = on;
> + pm_runtime_put(&client->dev);
> goto unlock;
> }
>
> + ret = pm_runtime_get_sync(&client->dev);
> + if (ret < 0) {
> + pm_runtime_put_noidle(&client->dev);
> + goto unlock;
> + }
> +
> + ov2659_init(sd, 0);
> ov2659_set_pixel_clock(ov2659);
> ov2659_set_frame_size(ov2659);
> ov2659_set_format(ov2659);
> @@ -1243,6 +1258,32 @@ static const char * const ov2659_test_pattern_menu[] = {
> "Vertical Color Bars",
> };
>
> +static int ov2659_set_power(struct ov2659 *ov2659, int on)
> +{
> + struct i2c_client *client = ov2659->client;
> +
> + dev_dbg(&client->dev, "%s: on: %d\n", __func__, on);
> +
> + if (on) {
> + if (ov2659->pwdn_gpio)
> + gpiod_direction_output(ov2659->pwdn_gpio, 0);
> +
> + if (ov2659->resetb_gpio) {
> + gpiod_set_value(ov2659->resetb_gpio, 1);
> + usleep_range(500, 1000);
> + gpiod_set_value(ov2659->resetb_gpio, 0);
> + usleep_range(3000, 5000);
> + }
Please move the code to the runtime PM callbacks.
> + } else {
> + if (ov2659->pwdn_gpio)
> + gpiod_direction_output(ov2659->pwdn_gpio, 1);
Gpiod API works with NULL GPIOs, too, so no need to check here.
Isn't the direction supposed to be already output, so set_value would be
more appropriate here, and above.
> + }
> +
> + ov2659->on = on;
> +
> + return 0;
> +}
> +
> /* -----------------------------------------------------------------------------
> * V4L2 subdev internal operations
> */
> @@ -1323,7 +1364,6 @@ static int ov2659_detect(struct v4l2_subdev *sd)
> ret = -ENODEV;
> } else {
> dev_info(&client->dev, "Found OV%04X sensor\n", id);
> - ret = ov2659_init(sd, 0);
> }
> }
>
> @@ -1400,6 +1440,18 @@ static int ov2659_probe(struct i2c_client *client)
> ov2659->xvclk_frequency > 27000000)
> return -EINVAL;
>
> + /* Optional gpio don't fail if not present */
> + ov2659->pwdn_gpio = devm_gpiod_get_optional(&client->dev, "powerdown",
> + GPIOD_OUT_LOW);
> + if (IS_ERR(ov2659->pwdn_gpio))
> + return PTR_ERR(ov2659->pwdn_gpio);
> +
> + /* Optional gpio don't fail if not present */
> + ov2659->resetb_gpio = devm_gpiod_get_optional(&client->dev, "reset",
> + GPIOD_OUT_HIGH);
> + if (IS_ERR(ov2659->resetb_gpio))
> + return PTR_ERR(ov2659->resetb_gpio);
> +
> v4l2_ctrl_handler_init(&ov2659->ctrls, 2);
> ov2659->link_frequency =
> v4l2_ctrl_new_std(&ov2659->ctrls, &ov2659_ctrl_ops,
> @@ -1445,6 +1497,9 @@ static int ov2659_probe(struct i2c_client *client)
> ov2659->frame_size = &ov2659_framesizes[2];
> ov2659->format_ctrl_regs = ov2659_formats[0].format_ctrl_regs;
>
> + pm_runtime_enable(&client->dev);
> + pm_runtime_get_sync(&client->dev);
This makes the driver depend on runtime PM.
See e.g. the smiapp driver for an example how to make it work without. It
wasn't trivial. :I You won't need autosuspend.
> +
> ret = ov2659_detect(sd);
> if (ret < 0)
> goto error;
> @@ -1458,10 +1513,14 @@ static int ov2659_probe(struct i2c_client *client)
>
> dev_info(&client->dev, "%s sensor driver registered !!\n", sd->name);
>
> + pm_runtime_put(&client->dev);
> +
> return 0;
>
> error:
> v4l2_ctrl_handler_free(&ov2659->ctrls);
> + pm_runtime_put(&client->dev);
> + pm_runtime_disable(&client->dev);
> media_entity_cleanup(&sd->entity);
> mutex_destroy(&ov2659->lock);
> return ret;
> @@ -1477,9 +1536,35 @@ static int ov2659_remove(struct i2c_client *client)
> media_entity_cleanup(&sd->entity);
> mutex_destroy(&ov2659->lock);
>
> + pm_runtime_disable(&client->dev);
> +
> return 0;
> }
>
> +static int ov2659_runtime_suspend(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> + struct ov2659 *ov2659 = to_ov2659(sd);
> +
> + ov2659_set_power(ov2659, 0);
> +
> + return 0;
> +}
> +
> +static int ov2659_runtime_resume(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct v4l2_subdev *sd = i2c_get_clientdata(client);
> + struct ov2659 *ov2659 = to_ov2659(sd);
> +
> + return ov2659_set_power(ov2659, 1);
> +}
> +
> +static const struct dev_pm_ops ov2659_pm_ops = {
> + SET_RUNTIME_PM_OPS(ov2659_runtime_suspend, ov2659_runtime_resume, NULL)
> +};
> +
> static const struct i2c_device_id ov2659_id[] = {
> { "ov2659", 0 },
> { /* sentinel */ },
> @@ -1497,6 +1582,7 @@ MODULE_DEVICE_TABLE(of, ov2659_of_match);
> static struct i2c_driver ov2659_i2c_driver = {
> .driver = {
> .name = DRIVER_NAME,
> + .pm = &ov2659_pm_ops,
> .of_match_table = of_match_ptr(ov2659_of_match),
> },
> .probe_new = ov2659_probe,
--
Kind regards,
Sakari Ailus
sakari.ailus@...ux.intel.com
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