Re: [RFC 2/4] pwm: sifive: Add a driver for SiFive SoC PWM

[Atish Patra]

On 10/10/18 6:11 AM, Christoph Hellwig wrote:
> Thanks for getting these drivers submitted upstream!
>
> I don't really know anything about PWM, so just some random nitpicking
> below..
>
> > +	iowrite32(frac, pwm->regs + REG_PWMCMP0 + (dev->hwpwm * SIZE_PWMCMP));
>
> * already has a higher precedence than +, so no need for the inner
> braces.
>
> > +	duty = ioread32(pwm->regs + REG_PWMCMP0 + (dev->hwpwm * SIZE_PWMCMP));
>
> Same here.

Will remove the braces in both places.
> > +	/* (1 << (16+scale)) * 10^9/rate = real_period */
> 	unsigned long scalePow = (pwm->approx_period * (u64)rate) / 1000000000;
>
> no camcel case, please.

My bad. I will fix that.

> > +	int scale = ilog2(scalePow) - 16;
> > +
> > +	scale = clamp(scale, 0, 0xf);
>
> Why not:
>
> 	int scale = clamp(ilog2(scale_pow) - 16, 0, 0xf);

Sure.

> > +static int sifive_pwm_clock_notifier(struct notifier_block *nb,
> > +				     unsigned long event, void *data)
> > +{
> > +	struct clk_notifier_data *ndata = data;
> > +	struct sifive_pwm_device *pwm = container_of(nb,
> > +						     struct sifive_pwm_device,
> > +						     notifier);
>
> I don't think there are any guidlines, but I always prefer to just move
> the whole container_of onto a new line:
>
> 	struct sifive_pwm_device *pwm =
> 		container_of(nb, struct sifive_pwm_device, notifier);

Done.

Regards,
Atish
> > +static struct platform_driver sifive_pwm_driver = {
> > +	.probe = sifive_pwm_probe,
> > +	.remove = sifive_pwm_remove,
> > +	.driver = {
> > +		.name = "pwm-sifivem",
> > +		.of_match_table = of_match_ptr(sifive_pwm_of_match),
> > +	},
> > +};
>
> What about using tabs to align this a little more nicely?
>
> static struct platform_driver sifive_pwm_driver = {
> 	.probe			= sifive_pwm_probe,
> 	.remove			= sifive_pwm_remove,
> 	.driver = {
> 		.name		= "pwm-sifivem",
> 		.of_match_table	= of_match_ptr(sifive_pwm_of_match),
> 	},
> };