[v8,3/6] pwm: sun4i: Add an optional probe for bus clock
diff mbox series

Message ID 20191121195902.6906-4-peron.clem@gmail.com
State Superseded
Headers show
Series
  • Add support for H6 PWM
Related show

Commit Message

Clément Péron Nov. 21, 2019, 7:58 p.m. UTC
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(+)

Comments

Uwe Kleine-König Nov. 21, 2019, 9:05 p.m. UTC | #1
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.

Best regards
Uwe
Clément Péron Nov. 21, 2019, 9:31 p.m. UTC | #2
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/ |

Patch
diff mbox series

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);
+		goto err_bus;
+	}
+
 	pwm->chip.dev = &pdev->dev;
 	pwm->chip.ops = &sun4i_pwm_ops;
 	pwm->chip.base = -1;
@@ -427,6 +447,8 @@  static int sun4i_pwm_probe(struct platform_device *pdev)
 	return 0;
 
 err_pwm_add:
+	clk_disable_unprepare(pwm->bus_clk);
+err_bus:
 	reset_control_assert(pwm->rst);
 
 	return ret;
@@ -441,6 +463,7 @@  static int sun4i_pwm_remove(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	clk_disable_unprepare(pwm->bus_clk);
 	reset_control_assert(pwm->rst);
 
 	return 0;