linux-kernel - Re: [PATCH v5 7/7] backlight: gpio: pull gpio_backlight_initial_power

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Message-ID: <20191007125603.qmb6jfu2tjxnzmm6@holly.lan>
Date:   Mon, 7 Oct 2019 13:56:03 +0100
From:   Daniel Thompson <daniel.thompson@...aro.org>
To:     Bartosz Golaszewski <brgl@...ev.pl>
Cc:     Yoshinori Sato <ysato@...rs.sourceforge.jp>,
        Rich Felker <dalias@...c.org>,
        Lee Jones <lee.jones@...aro.org>,
        Jingoo Han <jingoohan1@...il.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Jacopo Mondi <jacopo@...ndi.org>, linux-sh@...r.kernel.org,
        linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        linux-fbdev@...r.kernel.org,
        Bartosz Golaszewski <bgolaszewski@...libre.com>
Subject: Re: [PATCH v5 7/7] backlight: gpio: pull
 gpio_backlight_initial_power_state() into probe

On Mon, Oct 07, 2019 at 05:32:00AM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@...libre.com>
> 
> The probe function in the gpio-backlight driver is quite short. If we
> pull gpio_backlight_initial_power_state() into probe we can drop two
> more fields from struct gpio_backlight and shrink the driver code.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@...libre.com>

Acked-by: Daniel Thompson <daniel.thompson@...aro.org>

> ---
>  drivers/video/backlight/gpio_backlight.c | 37 +++++++++---------------
>  1 file changed, 13 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/video/backlight/gpio_backlight.c b/drivers/video/backlight/gpio_backlight.c
> index 6247687b6330..407d4eaafc5c 100644
> --- a/drivers/video/backlight/gpio_backlight.c
> +++ b/drivers/video/backlight/gpio_backlight.c
> @@ -17,11 +17,8 @@
>  #include <linux/slab.h>
>  
>  struct gpio_backlight {
> -	struct device *dev;
>  	struct device *fbdev;
> -
>  	struct gpio_desc *gpiod;
> -	int def_value;
>  };
>  
>  static int gpio_backlight_update_status(struct backlight_device *bl)
> @@ -53,41 +50,24 @@ static const struct backlight_ops gpio_backlight_ops = {
>  	.check_fb	= gpio_backlight_check_fb,
>  };
>  
> -static int gpio_backlight_initial_power_state(struct gpio_backlight *gbl)
> -{
> -	struct device_node *node = gbl->dev->of_node;
> -
> -	/* Not booted with device tree or no phandle link to the node */
> -	if (!node || !node->phandle)
> -		return gbl->def_value ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
> -
> -	/* if the enable GPIO is disabled, do not enable the backlight */
> -	if (gpiod_get_value_cansleep(gbl->gpiod) == 0)
> -		return FB_BLANK_POWERDOWN;
> -
> -	return FB_BLANK_UNBLANK;
> -}
> -
> -
>  static int gpio_backlight_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct gpio_backlight_platform_data *pdata = dev_get_platdata(dev);
> +	struct device_node *of_node = dev->of_node;
>  	struct backlight_properties props;
>  	struct backlight_device *bl;
>  	struct gpio_backlight *gbl;
> -	int ret;
> +	int ret, def_value;
>  
>  	gbl = devm_kzalloc(dev, sizeof(*gbl), GFP_KERNEL);
>  	if (gbl == NULL)
>  		return -ENOMEM;
>  
> -	gbl->dev = dev;
> -
>  	if (pdata)
>  		gbl->fbdev = pdata->fbdev;
>  
> -	gbl->def_value = device_property_read_bool(dev, "default-on");
> +	def_value = device_property_read_bool(dev, "default-on");
>  
>  	gbl->gpiod = devm_gpiod_get(dev, NULL, GPIOD_ASIS);
>  	if (IS_ERR(gbl->gpiod)) {
> @@ -109,7 +89,16 @@ static int gpio_backlight_probe(struct platform_device *pdev)
>  		return PTR_ERR(bl);
>  	}
>  
> -	bl->props.power = gpio_backlight_initial_power_state(gbl);
> +	/* Set the initial power state */
> +	if (!of_node || !of_node->phandle)
> +		/* Not booted with device tree or no phandle link to the node */
> +		bl->props.power = def_value ? FB_BLANK_UNBLANK
> +					    : FB_BLANK_POWERDOWN;
> +	else if (gpiod_get_value_cansleep(gbl->gpiod) == 0)
> +		bl->props.power = FB_BLANK_POWERDOWN;
> +	else
> +		bl->props.power = FB_BLANK_UNBLANK;
> +
>  	bl->props.brightness = 1;
>  
>  	backlight_update_status(bl);
> -- 
> 2.23.0
>