Re: [PATCH v17 03/10] video: backlight: Add of_find_backlight helper in backlight.c

["Noralf Trønnes" <noralf@tronnes.org>]

Den 19.01.2018 12.05, skrev Daniel Thompson:
> On Fri, Jan 19, 2018 at 10:42:15AM +0000, Meghana Madhyastha wrote:
>> Add of_find_backlight, a helper function which is a generic version
>> of tinydrm_of_find_backlight that can be used by other drivers to avoid
>> repetition of code and simplify things.
>>
>> Signed-off-by: Meghana Madhyastha <meghana.madhyastha@gmail.com>
> Didn't I already ack this one?

Meghana,

You are supposed to pick up the r-b/acks you get and add them when you send
a new version. This way the reviewer knows which patches still need 
attention.

Here's a good overview of the acks/r-b's you've received:
https://patchwork.freedesktop.org/project/dri-devel/patches/?submitter=17149

Beware that r-b/ack to the cover letter doesn't show up in patchwork, like
Sean did on the last version putting his r-b on the whole series.
The same goes for someone putting an r-b in one of the patches stating that
it applies to whole series, patchwork thinks it only applies to this one 
patch.

Noralf.

>
>> ---
>> changes in v17:
>> -rebase with drm-misc-next
>> -convert st7735r callers from tinydrm specific helpers
>>   to new generic backlight helpers
>> -remove select BACKLIGHT_LCD_SUPPORT
>>   and select BACKLIGHT_CLASS_DEVICE from
>>   tinydrm/Kconfig
>>
>>   drivers/video/backlight/backlight.c | 43 +++++++++++++++++++++++++++++++++++++
>>   include/linux/backlight.h           | 19 ++++++++++++++++
>>   2 files changed, 62 insertions(+)
>>
>> diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
>> index 8049e7656..553bf5c48 100644
>> --- a/drivers/video/backlight/backlight.c
>> +++ b/drivers/video/backlight/backlight.c
>> @@ -580,6 +580,49 @@ struct backlight_device *of_find_backlight_by_node(struct device_node *node)
>>   EXPORT_SYMBOL(of_find_backlight_by_node);
>>   #endif
>>   
>> +/**
>> + * of_find_backlight - Get backlight device
>> + * @dev: Device
>> + *
>> + * This function looks for a property named 'backlight' on the DT node
>> + * connected to @dev and looks up the backlight device.
>> + *
>> + * Call backlight_put() to drop the reference on the backlight device.
>> + *
>> + * Returns:
>> + * A pointer to the backlight device if found.
>> + * Error pointer -EPROBE_DEFER if the DT property is set, but no backlight
>> + * device is found.
>> + * NULL if there's no backlight property.
>> + */
>> +struct backlight_device *of_find_backlight(struct device *dev)
>> +{
>> +	struct backlight_device *bd = NULL;
>> +	struct device_node *np;
>> +
>> +	if (!dev)
>> +		return NULL;
>> +
>> +	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
>> +		np = of_parse_phandle(dev->of_node, "backlight", 0);
>> +		if (np) {
>> +			bd = of_find_backlight_by_node(np);
>> +			of_node_put(np);
>> +			if (!bd)
>> +				return ERR_PTR(-EPROBE_DEFER);
>> +			/*
>> +			 * Note: gpio_backlight uses brightness as
>> +			 * power state during probe
>> +			 */
>> +			if (!bd->props.brightness)
>> +				bd->props.brightness = bd->props.max_brightness;
>> +		}
>> +	}
>> +
>> +	return bd;
>> +}
>> +EXPORT_SYMBOL(of_find_backlight);
>> +
>>   static void __exit backlight_class_exit(void)
>>   {
>>   	class_destroy(backlight_class);
>> diff --git a/include/linux/backlight.h b/include/linux/backlight.h
>> index ace825e2c..ddc9bade4 100644
>> --- a/include/linux/backlight.h
>> +++ b/include/linux/backlight.h
>> @@ -162,6 +162,16 @@ static inline int backlight_disable(struct backlight_device *bd)
>>   	return backlight_update_status(bd);
>>   }
>>   
>> +/**
>> + * backlight_put - Drop backlight reference
>> + * @bd: the backlight device to put
>> + */
>> +static inline void backlight_put(struct backlight_device *bd)
>> +{
>> +	if (bd)
>> +		put_device(&bd->dev);
>> +}
>> +
>>   extern struct backlight_device *backlight_device_register(const char *name,
>>   	struct device *dev, void *devdata, const struct backlight_ops *ops,
>>   	const struct backlight_properties *props);
>> @@ -205,4 +215,13 @@ of_find_backlight_by_node(struct device_node *node)
>>   }
>>   #endif
>>   
>> +#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)
>> +struct backlight_device *of_find_backlight(struct device *dev);
>> +#else
>> +static inline struct backlight_device *of_find_backlight(struct device *dev)
>> +{
>> +	return NULL;
>> +}
>> +#endif
>> +
>>   #endif
>> -- 
>> 2.11.0
>>