Re: [PATCH v8 3/6] pwm: sun4i: Add an optional probe for bus clock

Clément Péron
2019-11-21T21:31:47Z

Hi Uwe,

On Thu, 21 Nov 2019 at 22:06, Uwe Kleine-König
<u.kleine-koenig@pengutronix.de> wrote:
>
> On Thu, Nov 21, 2019 at 08:58:59PM +0100, Clément Péron wrote:
> > From: Jernej Skrabec <jernej.skrabec@siol.net>
> >
> > H6 PWM core needs bus clock to be enabled in order to work.
> >
> > Add an optional probe for it.
> >
> > Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
> > Signed-off-by: Clément Péron <peron.clem@gmail.com>
> > ---
> > drivers/pwm/pwm-sun4i.c | 23 +++++++++++++++++++++++
> > 1 file changed, 23 insertions(+)
> >
> > diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
> > index 369990ae7d09..66befd8d6f9c 100644
> > --- a/drivers/pwm/pwm-sun4i.c
> > +++ b/drivers/pwm/pwm-sun4i.c
> > @@ -78,6 +78,7 @@ struct sun4i_pwm_data {
> >
> > struct sun4i_pwm_chip {
> > struct pwm_chip chip;
> > + struct clk *bus_clk;
> > struct clk *clk;
> > struct reset_control *rst;
> > void __iomem *base;
> > @@ -391,6 +392,14 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
> > }
> > }
> >
> > + pwm->bus_clk = devm_clk_get_optional(&pdev->dev, "bus");
> > + if (IS_ERR(pwm->bus_clk)) {
> > + if (PTR_ERR(pwm->rst) != -EPROBE_DEFER)
> > + dev_err(&pdev->dev, "get bus clock failed %pe\n",
> > + pwm->bus_clk);
> > + return PTR_ERR(pwm->bus_clk);
> > + }
> > +
> > pwm->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
> > if (IS_ERR(pwm->rst)) {
> > if (PTR_ERR(pwm->rst) != -EPROBE_DEFER)
> > @@ -407,6 +416,17 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
> > return ret;
> > }
> >
> > + /*
> > + * We're keeping the bus clock on for the sake of simplicity.
> > + * Actually it only needs to be on for hardware register accesses.
> > + */
> > + ret = clk_prepare_enable(pwm->bus_clk);
> > + if (ret) {
> > + dev_err(&pdev->dev, "Cannot prepare and enable bus_clk %d\n",
> > + ret);
>
> nitpick: other error messages in this driver start with a lower case
> letter.
>
> Until there is an equivalent for %pe that consumes an int, I suggest to
> use
>
> dev_err(&pdev->dev, "Cannot prepare and enable bus_clk: %pe\n",
> ERR_PTR(ret));
>
> to benefit from a symbolic error name instead of an error constant.

Ok i will fix both

Thanks,
Clement

>
> Best regards
> Uwe
>
> --
> Pengutronix e.K. | Uwe Kleine-König |
> Industrial Linux Solutions | https://www.pengutronix.de/ |