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SubjectRe: [Patch v4 6/8] media: i2c: ov2659: Add powerdown/reset gpio handling
Hi Benoit,

thank you for the patch.

On Fri, Sep 27, 2019 at 7:49 PM Benoit Parrot <bparrot@ti.com> 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 when it is available otherwise the sensor will be
> powered on at module insertion/probe and powered off at module removal.
>
> Now originally the driver assumed that the sensor would always stay
> powered and keep its register setting. We cannot assume 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@ti.com>
> ---
> drivers/media/i2c/Kconfig | 2 +-
> drivers/media/i2c/ov2659.c | 88 +++++++++++++++++++++++++++++++++++++-
> 2 files changed, 87 insertions(+), 3 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 cd4625432264..7d0baa386644 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[] = {
> @@ -1184,10 +1191,19 @@ 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 = ov2659_set_pixel_clock(ov2659);
> + ret = pm_runtime_get_sync(&client->dev);
> + if (ret < 0) {
> + pm_runtime_put_noidle(&client->dev);
> + goto unlock;
> + }
> +
> + ret = ov2659_init(sd, 0);
> + if (!ret)
> + ret = ov2659_set_pixel_clock(ov2659);
> if (!ret)
> ret = ov2659_set_frame_size(ov2659);
> if (!ret)
> @@ -1229,6 +1245,9 @@ static int ov2659_s_ctrl(struct v4l2_ctrl *ctrl)
> struct ov2659 *ov2659 =
> container_of(ctrl->handler, struct ov2659, ctrls);
>
> + if (!ov2659->on)
> + return 0;
> +
why is this check only in s_ctrl() ? I think we could just drop this variable.

Cheers,
--Prabhakar

> switch (ctrl->id) {
> case V4L2_CID_TEST_PATTERN:
> return ov2659_set_test_pattern(ov2659, ctrl->val);
> @@ -1246,6 +1265,43 @@ static const char * const ov2659_test_pattern_menu[] = {
> "Vertical Color Bars",
> };
>
> +static int ov2659_power_off(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);
> +
> + dev_dbg(&client->dev, "%s:\n", __func__);
> +
> + gpiod_set_value(ov2659->pwdn_gpio, 1);
> +
> + ov2659->on = false;
> +
> + return 0;
> +}
> +
> +static int ov2659_power_on(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);
> +
> + dev_dbg(&client->dev, "%s:\n", __func__);
> +
> + gpiod_set_value(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);
> + }
> +
> + ov2659->on = true;
> +
> + return 0;
> +}
> +
> /* -----------------------------------------------------------------------------
> * V4L2 subdev internal operations
> */
> @@ -1326,7 +1382,6 @@ 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);
> }
> }
>
> @@ -1403,6 +1458,18 @@ 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,
> @@ -1448,6 +1515,8 @@ static int ov2659_probe(struct i2c_client *client)
> ov2659->frame_size = &ov2659_framesizes[2];
> ov2659->format_ctrl_regs = ov2659_formats[0].format_ctrl_regs;
>
> + ov2659_power_on(&client->dev);
> +
> ret = ov2659_detect(sd);
> if (ret < 0)
> goto error;
> @@ -1461,10 +1530,15 @@ static int ov2659_probe(struct i2c_client *client)
>
> dev_info(&client->dev, "%s sensor driver registered !!\n", sd->name);
>
> + pm_runtime_set_active(&client->dev);
> + pm_runtime_enable(&client->dev);
> + pm_runtime_idle(&client->dev);
> +
> return 0;
>
> error:
> v4l2_ctrl_handler_free(&ov2659->ctrls);
> + ov2659_power_off(&client->dev);
> media_entity_cleanup(&sd->entity);
> mutex_destroy(&ov2659->lock);
> return ret;
> @@ -1480,9 +1554,18 @@ static int ov2659_remove(struct i2c_client *client)
> media_entity_cleanup(&sd->entity);
> mutex_destroy(&ov2659->lock);
>
> + pm_runtime_disable(&client->dev);
> + if (!pm_runtime_status_suspended(&client->dev))
> + ov2659_power_off(&client->dev);
> + pm_runtime_set_suspended(&client->dev);
> +
> return 0;
> }
>
> +static const struct dev_pm_ops ov2659_pm_ops = {
> + SET_RUNTIME_PM_OPS(ov2659_power_off, ov2659_power_on, NULL)
> +};
> +
> static const struct i2c_device_id ov2659_id[] = {
> { "ov2659", 0 },
> { /* sentinel */ },
> @@ -1500,6 +1583,7 @@ 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,
> --
> 2.17.1
>

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