Re: [PATCH 6/8] leds: as3645a: Add LED flash class driver

[Jacek Anaszewski <jacek.anaszewski@gmail.com>]

Hi Sakari,

On 06/15/2017 12:10 AM, Sakari Ailus wrote:
> Hi Jacek,
> 
> Thanks for the review!

You're welcome!

> I have to say I found the v4l2-flash-led-class framework quite useful, now
> that I refactored a driver for using it. Now we have a user for the
> indicator, too. :-)

Nice :-). I'm also surprised that v4l2-flash API is also used in
drivers/staging/greybus/light.c which popped up with kbuild test robot
complaints.

> On Wed, Jun 14, 2017 at 11:15:24PM +0200, Jacek Anaszewski wrote:
>>> +static __maybe_unused int as3645a_suspend(struct device *dev)
>>> +{
>>> +	struct i2c_client *client = to_i2c_client(dev);
>>> +	struct as3645a *flash = i2c_get_clientdata(client);
>>> +	int rval;
>>> +
>>> +	rval = as3645a_set_control(flash, AS_MODE_EXT_TORCH, false);
>>> +	dev_dbg(dev, "Suspend %s\n", rval < 0 ? "failed" : "ok");
>>> +
>>> +	return rval;
>>> +}
>>> +
>>> +static __maybe_unused int as3645a_resume(struct device *dev)
>>> +{
>>> +	struct i2c_client *client = to_i2c_client(dev);
>>> +	struct as3645a *flash = i2c_get_clientdata(client);
>>> +	int rval;
>>> +
>>> +	rval = as3645a_setup(flash);
>>> +
>>
>> nitpicking: inconsistent coding style - there is no empty line before
>> dev_dbg() in the as3645a_suspend().
> 
> Added one for as3645a_suspend() --- it should have been there.
> 
>>
>>> +	dev_dbg(dev, "Resume %s\n", rval < 0 ? "fail" : "ok");
>>> +
>>> +	return rval;
>>> +}
> 
> ...
> 
>>> +static int as3645a_led_class_setup(struct as3645a *flash)
>>> +{
>>> +	struct led_classdev *fled_cdev = &flash->fled.led_cdev;
>>> +	struct led_classdev *iled_cdev = &flash->iled_cdev;
>>> +	struct led_flash_setting *cfg;
>>> +	int rval;
>>> +
>>> +	iled_cdev->name = "as3645a indicator";
>>> +	iled_cdev->brightness_set_blocking = as3645a_set_indicator_brightness;
>>> +	iled_cdev->max_brightness =
>>> +		flash->cfg.indicator_max_ua / AS_INDICATOR_INTENSITY_STEP;
>>> +
>>> +	rval = led_classdev_register(&flash->client->dev, iled_cdev);
>>> +	if (rval < 0)
>>> +		return rval;
>>> +
>>> +	cfg = &flash->fled.brightness;
>>> +	cfg->min = AS_FLASH_INTENSITY_MIN;
>>> +	cfg->max = flash->cfg.flash_max_ua;
>>> +	cfg->step = AS_FLASH_INTENSITY_STEP;
>>> +	cfg->val = flash->cfg.flash_max_ua;
>>> +
>>> +	cfg = &flash->fled.timeout;
>>> +	cfg->min = AS_FLASH_TIMEOUT_MIN;
>>> +	cfg->max = flash->cfg.flash_timeout_us;
>>> +	cfg->step = AS_FLASH_TIMEOUT_STEP;
>>> +	cfg->val = flash->cfg.flash_timeout_us;
>>> +
>>> +	flash->fled.ops = &as3645a_led_flash_ops;
>>> +
>>> +	fled_cdev->name = "as3645a flash";
>>
>> LED class device name should be taken from label DT property,
>> or DT node name if the former wasn't defined.
>>
>> Also LED device naming convention defines colon as a separator
>> between name segments.
> 
> Right. I'll fix that.
> 
> I just realised I'm missing DT binding documentation for this device; I'll
> add that, too.
> 
> Is the preference to allow freely chosen node names for the LEDs? Now that
> there's the label, too, this appears to be somewhat duplicated information.

It depends on whether the sub-leds are identified by reg property.
In this case usually common prefix is used followed by reg value,
e.g. led@1, led@2 etc.

Otherwise prevailing scheme is e.g.:

        blue-power {
		...
                label = "netxbig:blue:power";
	}

-- 
Best regards,
Jacek Anaszewski