linux-kernel - Re: [PATCH 1/4] media: i2c: s5k6a3: switch to using gpiod API

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Date:   Thu, 17 Nov 2022 10:11:20 +0100
From:   Tommaso Merciai <tommaso.merciai@...rulasolutions.com>
To:     Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:     Mauro Carvalho Chehab <mchehab@...nel.org>,
        Sylwester Nawrocki <s.nawrocki@...sung.com>,
        Andrzej Hajda <andrzej.hajda@...el.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        linux-kernel@...r.kernel.org, linux-media@...r.kernel.org
Subject: Re: [PATCH 1/4] media: i2c: s5k6a3: switch to using gpiod API

Hi Dmitry,

On Tue, Nov 15, 2022 at 02:11:42PM -0800, Dmitry Torokhov wrote:
> This patch switches the driver away from legacy gpio/of_gpio API to
> gpiod API, and removes one of the last uses of of_get_gpio_flags().
> 
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
> ---
>  drivers/media/i2c/s5k6a3.c | 30 +++++++++++-------------------
>  1 file changed, 11 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/media/i2c/s5k6a3.c b/drivers/media/i2c/s5k6a3.c
> index a4efd6d10b43..ef6673b10580 100644
> --- a/drivers/media/i2c/s5k6a3.c
> +++ b/drivers/media/i2c/s5k6a3.c
> @@ -9,12 +9,12 @@
>  #include <linux/clk.h>
>  #include <linux/delay.h>
>  #include <linux/device.h>
> +#include <linux/err.h>
>  #include <linux/errno.h>
> -#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
>  #include <linux/i2c.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
> -#include <linux/of_gpio.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/slab.h>
> @@ -59,7 +59,7 @@ struct s5k6a3 {
>  	struct v4l2_subdev subdev;
>  	struct media_pad pad;
>  	struct regulator_bulk_data supplies[S5K6A3_NUM_SUPPLIES];
> -	int gpio_reset;
> +	struct gpio_desc *gpio_reset;
>  	struct mutex lock;
>  	struct v4l2_mbus_framefmt format;
>  	struct clk *clock;
> @@ -216,11 +216,11 @@ static int __s5k6a3_power_on(struct s5k6a3 *sensor)
>  			goto error_clk;
>  	}
>  
> -	gpio_set_value(sensor->gpio_reset, 1);
> +	gpiod_set_value_cansleep(sensor->gpio_reset, 0);
>  	usleep_range(600, 800);
> -	gpio_set_value(sensor->gpio_reset, 0);
> +	gpiod_set_value_cansleep(sensor->gpio_reset, 1);
>  	usleep_range(600, 800);
> -	gpio_set_value(sensor->gpio_reset, 1);
> +	gpiod_set_value_cansleep(sensor->gpio_reset, 0);
>  
>  	/* Delay needed for the sensor initialization */
>  	msleep(20);
> @@ -240,7 +240,7 @@ static int __s5k6a3_power_off(struct s5k6a3 *sensor)
>  {
>  	int i;
>  
> -	gpio_set_value(sensor->gpio_reset, 0);
> +	gpiod_set_value_cansleep(sensor->gpio_reset, 1);
>  
>  	for (i = S5K6A3_NUM_SUPPLIES - 1; i >= 0; i--)
>  		regulator_disable(sensor->supplies[i].consumer);
> @@ -285,32 +285,24 @@ static int s5k6a3_probe(struct i2c_client *client)
>  	struct device *dev = &client->dev;
>  	struct s5k6a3 *sensor;
>  	struct v4l2_subdev *sd;
> -	int gpio, i, ret;
> +	int i, ret;
>  
>  	sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
>  	if (!sensor)
>  		return -ENOMEM;
>  
>  	mutex_init(&sensor->lock);
> -	sensor->gpio_reset = -EINVAL;
> -	sensor->clock = ERR_PTR(-EINVAL);
>  	sensor->dev = dev;
>  
>  	sensor->clock = devm_clk_get(sensor->dev, S5K6A3_CLK_NAME);
>  	if (IS_ERR(sensor->clock))
>  		return PTR_ERR(sensor->clock);
>  
> -	gpio = of_get_gpio_flags(dev->of_node, 0, NULL);
> -	if (!gpio_is_valid(gpio))
> -		return gpio;
> -
> -	ret = devm_gpio_request_one(dev, gpio, GPIOF_OUT_INIT_LOW,
> -						S5K6A3_DRV_NAME);
> -	if (ret < 0)
> +	sensor->gpio_reset = devm_gpiod_get(dev, NULL, GPIOD_OUT_HIGH);
> +	ret = PTR_ERR_OR_ZERO(sensor->gpio_reset);
> +	if (ret)
>  		return ret;

Patch looks good to me!
Reviewed-by: Tommaso Merciai <tommaso.merciai@...rulasolutions.com>

For the future I think would be nice use "reset-gpios" name in dts.
Then call:

	devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);

But this is a todo :)

Regards,
Tommaso

>  
> -	sensor->gpio_reset = gpio;
> -
>  	if (of_property_read_u32(dev->of_node, "clock-frequency",
>  				 &sensor->clock_frequency)) {
>  		sensor->clock_frequency = S5K6A3_DEFAULT_CLK_FREQ;
> -- 
> 2.38.1.431.g37b22c650d-goog
> 

-- 
Tommaso Merciai
Embedded Linux Engineer
tommaso.merciai@...rulasolutions.com
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