Re: [PATCH 2/4] [media] ad5820: Add support for enable pin

Sakari Ailus
2018-09-21T00:25:46Z

Hi Ricardo,

Thanks for the set! A few comments below...

On Thu, Sep 20, 2018 at 06:19:10PM +0200, Ricardo Ribalda Delgado wrote:
> This patch adds support for a programmable enable pin. It can be used in
> situations where the ANA-vcc is not configurable (dummy-regulator), or
> just to have a more fine control of the power saving.
>
> The use of the enable pin is optional

Missing period at the end of the sentence.

>
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
> ---
> drivers/media/i2c/Kconfig | 2 +-
> drivers/media/i2c/ad5820.c | 20 ++++++++++++++++++++
> 2 files changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index bfdb494686bf..1ba6eaaf58fb 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -321,7 +321,7 @@ config VIDEO_ML86V7667
>
> config VIDEO_AD5820
> tristate "AD5820 lens voice coil support"
> - depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER
> + depends on GPIOLIB && I2C && VIDEO_V4L2 && MEDIA_CONTROLLER
> ---help---
> This is a driver for the AD5820 camera lens voice coil.
> It is used for example in Nokia N900 (RX-51).
> diff --git a/drivers/media/i2c/ad5820.c b/drivers/media/i2c/ad5820.c
> index 22759aaa2dba..20931217e3b1 100644
> --- a/drivers/media/i2c/ad5820.c
> +++ b/drivers/media/i2c/ad5820.c
> @@ -27,6 +27,7 @@
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/regulator/consumer.h>
> +#include <linux/gpio/consumer.h>
>
> #include <media/v4l2-ctrls.h>
> #include <media/v4l2-device.h>
> @@ -55,6 +56,8 @@ struct ad5820_device {
> u32 focus_ramp_time;
> u32 focus_ramp_mode;
>
> + struct gpio_desc *enable_gpio;
> +
> struct mutex power_lock;
> int power_count;
>
> @@ -122,6 +125,9 @@ static int ad5820_power_off(struct ad5820_device *coil, bool standby)
> ret = ad5820_update_hw(coil);
> }
>
> + if (coil->enable_gpio)
> + gpiod_set_value_cansleep(coil->enable_gpio, 0);

gpiod_set_value_cansleep(), as I think most (or all?) similar functions,
are happy with NULL gpio descriptor. You can thus drop the NULL check here
and below.

> +
> ret2 = regulator_disable(coil->vana);
> if (ret)
> return ret;
> @@ -136,6 +142,9 @@ static int ad5820_power_on(struct ad5820_device *coil, bool restore)
> if (ret < 0)
> return ret;
>
> + if (coil->enable_gpio)
> + gpiod_set_value_cansleep(coil->enable_gpio, 1);
> +
> if (restore) {
> /* Restore the hardware settings. */
> coil->standby = false;
> @@ -146,6 +155,8 @@ static int ad5820_power_on(struct ad5820_device *coil, bool restore)
> return 0;
>
> fail:
> + if (coil->enable_gpio)
> + gpiod_set_value_cansleep(coil->enable_gpio, 0);
> coil->standby = true;
> regulator_disable(coil->vana);
>
> @@ -312,6 +323,15 @@ static int ad5820_probe(struct i2c_client *client,
> return ret;
> }
>
> + coil->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
> + GPIOD_OUT_LOW);
> + if (IS_ERR(coil->enable_gpio)) {
> + ret = PTR_ERR(coil->enable_gpio);
> + if (ret == -EPROBE_DEFER)
> + dev_err(&client->dev, "could not get enable gpio\n");
> + return ret;
> + }
> +
> mutex_init(&coil->power_lock);
>
> v4l2_i2c_subdev_init(&coil->subdev, client, &ad5820_ops);

--
Regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi