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

- From: Lars-Peter Clausen \<lars@metafoo.de\>
- Date: 2012-11-26 10:44:00 
- List: linux-fbdev
- Page: https://ratatoskr.run/linux-fbdev/2012/11/3962868
- Thread: https://ratatoskr.run/linux-sh/2012/11/3962839/t.md

```text
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.

>> +}
>> +
[...]
>> +#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.

>> +
>> +static SIMPLE_DEV_PM_OPS(gpio_backlight_pm_ops, gpio_backlight_suspend,
>> +			 gpio_backlight_resume);
>> +
>> +#endif
>> +
[...]
```