Re: [RFC PATCH RESEND 2/3] leds: upboard: Add LED support

[Javier Arteaga <javier@emutex.com>]

On Wed, Apr 25, 2018 at 07:15:45PM +0300, Andy Shevchenko wrote:
> On Sat, 2018-04-21 at 09:50 +0100, Javier Arteaga wrote:
> > Allow userspace to use the on-board LEDs as "upboard:<color>:".
> 
> > +	struct upboard_led *led = container_of(cdev, struct
> > upboard_led, cdev);
> 
> #define to_upboard_led(cdev) container_of(cdev, struct upboard_led,
> cdev)
> 
> ... led = to_upboard_led(cdev);
> 
> > +	struct upboard_led *led = container_of(cdev, struct
> > upboard_led, cdev);
> 
> Ditto.

Will do - thanks!

> > +static int __init upboard_led_probe(struct platform_device *pdev)
> 
> Are you sure about __init here?

Not 100% now :)

My understanding was that in this context, __init allows this probe() to
be dropped from memory after module load.

What am I doing wrong there?

> > +	struct upboard_led_data * const pdata = pdev-
> > >dev.platform_data;
> 
> Don't use direct dereference to platform_data.

Sorry, I don't understand this one. What's the alternative?

> > +	if (!pdev->dev.parent)
> > +		return -EINVAL;
> > +
> > +	upboard = dev_get_drvdata(pdev->dev.parent);
> > +	if (!upboard || !pdata)
> > +		return -EINVAL;
> 
> Wouldn't be better to supply regmap as part of platform data?
> It will allow be flexible of parent device.

I'll play around with that.

> > +MODULE_LICENSE("GPL");
> 
> License mismatch.

Will fix.