# Re: \[PATCH 1/5\] backlight: Add GPIO-based backlight driver

- From: Laurent Pinchart \<laurent.pinchart@ideasonboard.com\>
- Date: 2012-11-26 11:58:09 
- List: linux-fbdev
- Page: https://ratatoskr.run/linux-fbdev/2012/11/3962910
- Thread: https://ratatoskr.run/linux-sh/2012/11/3962839/t.md

```text
Hi Lars-Peter,

On Monday 26 November 2012 11:44:04 Lars-Peter Clausen wrote:
> On 11/26/2012 10:49 AM, Jingoo Han wrote:
> > On Saturday, November 24, 2012 1:35 AM, Laurent Pinchart wrote
> 
> [...]
> 
> >> +static int gpio_backlight_check_fb(struct backlight_device *bl,
> >> +				   struct fb_info *info)
> >> +{
> >> +	struct gpio_backlight *gbl = bl_get_data(bl);
> >> +
> >> +	return gbl->fbdev = info->dev;
> 
> I think it makes sense to return true if fbdev is NULL, to provide a simple
> fallback for systems with only one framebuffer device.

Agreed, I'll change that.

> >> +}
> >> +
> 
> [...]
> 
> >> +#ifdef CONFIG_PM
> >> +static int gpio_backlight_suspend(struct device *dev)
> >> +{
> >> +	struct backlight_device *bl = dev_get_drvdata(dev);
> >> +	struct gpio_backlight *gbl = bl_get_data(bl);
> >> +
> >> +	gpio_set_value(gbl->gpio, !gbl->active);
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static int gpio_backlight_resume(struct device *dev)
> >> +{
> >> +	struct backlight_device *bl = dev_get_drvdata(dev);
> >> +
> >> +	backlight_update_status(bl);
> >> +	return 0;
> >> +}
> 
> If you use BL_CORE_SUSPENDRESUME you can get rid of the custom
> suspend/resume handlers.

Good point, I'll do that.

> >> +
> >> +static SIMPLE_DEV_PM_OPS(gpio_backlight_pm_ops, gpio_backlight_suspend,
> >> +			 gpio_backlight_resume);
> >> +
> >> +#endif
> >> +

-- 
Regards,

Laurent Pinchart

```