Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1276070 > unrolled thread

[PATCH] pwm: berlin: Add PM support

Back to article view | Back to linux.kernel

Contents

  [PATCH] pwm: berlin: Add PM support Jisheng Zhang <jszhang@marvell.com> - 2015-11-24 06:50 +0100
    Re: [PATCH] pwm: berlin: Add PM support Thierry Reding <thierry.reding@gmail.com> - 2015-11-24 17:30 +0100
      Re: [PATCH] pwm: berlin: Add PM support Jisheng Zhang <jszhang@marvell.com> - 2015-11-25 09:40 +0100
        Re: [PATCH] pwm: berlin: Add PM support Thierry Reding <thierry.reding@gmail.com> - 2015-11-25 16:20 +0100
          Re: [PATCH] pwm: berlin: Add PM support Jisheng Zhang <jszhang@marvell.com> - 2015-11-26 08:50 +0100

#1276070 — [PATCH] pwm: berlin: Add PM support

This patch adds S2R support for berlin pwm driver.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
---
 drivers/pwm/pwm-berlin.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 56 insertions(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-berlin.c b/drivers/pwm/pwm-berlin.c
index 6510812..2afdb40 100644
--- a/drivers/pwm/pwm-berlin.c
+++ b/drivers/pwm/pwm-berlin.c
@@ -27,10 +27,20 @@
 #define BERLIN_PWM_TCNT			0xc
 #define  BERLIN_PWM_MAX_TCNT		65535
 
+#define NUM_PWM_CHANNEL			4	/* berlin PWM channels */
+
+struct berlin_pwm_context {
+	u32	enable;
+	u32	ctrl;
+	u32	duty;
+	u32	tcnt;
+};
+
 struct berlin_pwm_chip {
 	struct pwm_chip chip;
 	struct clk *clk;
 	void __iomem *base;
+	struct berlin_pwm_context ctx[NUM_PWM_CHANNEL];
 };
 
 static inline struct berlin_pwm_chip *to_berlin_pwm_chip(struct pwm_chip *chip)
@@ -176,7 +186,7 @@ static int berlin_pwm_probe(struct platform_device *pdev)
 	pwm->chip.dev = &pdev->dev;
 	pwm->chip.ops = &berlin_pwm_ops;
 	pwm->chip.base = -1;
-	pwm->chip.npwm = 4;
+	pwm->chip.npwm = NUM_PWM_CHANNEL;
 	pwm->chip.can_sleep = true;
 	pwm->chip.of_xlate = of_pwm_xlate_with_flags;
 	pwm->chip.of_pwm_n_cells = 3;
@@ -204,12 +214,57 @@ static int berlin_pwm_remove(struct platform_device *pdev)
 	return ret;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int berlin_pwm_suspend(struct device *dev)
+{
+	int i;
+	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
+
+	for (i = 0; i < pwm->chip.npwm; i++) {
+		struct berlin_pwm_context *ctx = &pwm->ctx[i];
+
+		ctx->enable = berlin_pwm_readl(pwm, i, BERLIN_PWM_ENABLE);
+		ctx->ctrl = berlin_pwm_readl(pwm, i, BERLIN_PWM_CONTROL);
+		ctx->duty = berlin_pwm_readl(pwm, i, BERLIN_PWM_DUTY);
+		ctx->tcnt = berlin_pwm_readl(pwm, i, BERLIN_PWM_TCNT);
+	}
+	clk_disable_unprepare(pwm->clk);
+
+	return 0;
+}
+
+static int berlin_pwm_resume(struct device *dev)
+{
+	int i;
+	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
+
+	clk_prepare_enable(pwm->clk);
+	for (i = 0; i < pwm->chip.npwm; i++) {
+		struct berlin_pwm_context *ctx = &pwm->ctx[i];
+
+		berlin_pwm_writel(pwm, i, ctx->ctrl, BERLIN_PWM_CONTROL);
+		berlin_pwm_writel(pwm, i, ctx->duty, BERLIN_PWM_DUTY);
+		berlin_pwm_writel(pwm, i, ctx->tcnt, BERLIN_PWM_TCNT);
+		berlin_pwm_writel(pwm, i, ctx->enable, BERLIN_PWM_ENABLE);
+	}
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend,
+			 berlin_pwm_resume);
+#define BERLIN_PWM_PM_OPS	(&berlin_pwm_pm_ops)
+#else
+#define BERLIN_PWM_PM_OPS	NULL
+#endif
+
 static struct platform_driver berlin_pwm_driver = {
 	.probe = berlin_pwm_probe,
 	.remove = berlin_pwm_remove,
 	.driver = {
 		.name = "berlin-pwm",
 		.of_match_table = berlin_pwm_match,
+		.pm = BERLIN_PWM_PM_OPS,
 	},
 };
 module_platform_driver(berlin_pwm_driver);
-- 
2.6.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [next] | [standalone]

#1276622

[Multipart message — attachments visible in raw view] — view raw

On Tue, Nov 24, 2015 at 01:43:05PM +0800, Jisheng Zhang wrote:
> This patch adds S2R support for berlin pwm driver.
> 
> Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> ---
>  drivers/pwm/pwm-berlin.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 56 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pwm/pwm-berlin.c b/drivers/pwm/pwm-berlin.c
> index 6510812..2afdb40 100644
> --- a/drivers/pwm/pwm-berlin.c
> +++ b/drivers/pwm/pwm-berlin.c
> @@ -27,10 +27,20 @@
>  #define BERLIN_PWM_TCNT			0xc
>  #define  BERLIN_PWM_MAX_TCNT		65535
>  
> +#define NUM_PWM_CHANNEL			4	/* berlin PWM channels */
> +
> +struct berlin_pwm_context {
> +	u32	enable;
> +	u32	ctrl;
> +	u32	duty;
> +	u32	tcnt;
> +};
> +
>  struct berlin_pwm_chip {
>  	struct pwm_chip chip;
>  	struct clk *clk;
>  	void __iomem *base;
> +	struct berlin_pwm_context ctx[NUM_PWM_CHANNEL];

Please don't do this. You can easily attach per-PWM data using the
pwm_set_chip_data() function and retrieve it using pwm_get_chip_data().

>  };
>  
>  static inline struct berlin_pwm_chip *to_berlin_pwm_chip(struct pwm_chip *chip)
> @@ -176,7 +186,7 @@ static int berlin_pwm_probe(struct platform_device *pdev)
>  	pwm->chip.dev = &pdev->dev;
>  	pwm->chip.ops = &berlin_pwm_ops;
>  	pwm->chip.base = -1;
> -	pwm->chip.npwm = 4;
> +	pwm->chip.npwm = NUM_PWM_CHANNEL;
>  	pwm->chip.can_sleep = true;
>  	pwm->chip.of_xlate = of_pwm_xlate_with_flags;
>  	pwm->chip.of_pwm_n_cells = 3;
> @@ -204,12 +214,57 @@ static int berlin_pwm_remove(struct platform_device *pdev)
>  	return ret;
>  }
>  
> +#ifdef CONFIG_PM_SLEEP
> +static int berlin_pwm_suspend(struct device *dev)
> +{
> +	int i;

unsigned int, please.

> +	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
> +
> +	for (i = 0; i < pwm->chip.npwm; i++) {
> +		struct berlin_pwm_context *ctx = &pwm->ctx[i];
> +
> +		ctx->enable = berlin_pwm_readl(pwm, i, BERLIN_PWM_ENABLE);
> +		ctx->ctrl = berlin_pwm_readl(pwm, i, BERLIN_PWM_CONTROL);
> +		ctx->duty = berlin_pwm_readl(pwm, i, BERLIN_PWM_DUTY);
> +		ctx->tcnt = berlin_pwm_readl(pwm, i, BERLIN_PWM_TCNT);
> +	}
> +	clk_disable_unprepare(pwm->clk);
> +
> +	return 0;
> +}
> +
> +static int berlin_pwm_resume(struct device *dev)
> +{
> +	int i;

unsigned int, please.

> +	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
> +
> +	clk_prepare_enable(pwm->clk);

Always check the return value of this function.

> +	for (i = 0; i < pwm->chip.npwm; i++) {
> +		struct berlin_pwm_context *ctx = &pwm->ctx[i];
> +
> +		berlin_pwm_writel(pwm, i, ctx->ctrl, BERLIN_PWM_CONTROL);
> +		berlin_pwm_writel(pwm, i, ctx->duty, BERLIN_PWM_DUTY);
> +		berlin_pwm_writel(pwm, i, ctx->tcnt, BERLIN_PWM_TCNT);
> +		berlin_pwm_writel(pwm, i, ctx->enable, BERLIN_PWM_ENABLE);
> +	}
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend,
> +			 berlin_pwm_resume);
> +#define BERLIN_PWM_PM_OPS	(&berlin_pwm_pm_ops)
> +#else
> +#define BERLIN_PWM_PM_OPS	NULL
> +#endif

This is a weird way of writing this. I think a more typical way would be
to have the #ifdef contain only the implementation and then define the
dev_pm_ops variable unconditonally, so you don't need a separate macro
for it.

Thierry

[toc] | [prev] | [next] | [standalone]

#1277096

Dear Thierry,

On Tue, 24 Nov 2015 17:23:06 +0100
Thierry Reding wrote:

> On Tue, Nov 24, 2015 at 01:43:05PM +0800, Jisheng Zhang wrote:
> > This patch adds S2R support for berlin pwm driver.
> > 
> > Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> > ---
> >  drivers/pwm/pwm-berlin.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++-
> >  1 file changed, 56 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/pwm/pwm-berlin.c b/drivers/pwm/pwm-berlin.c
> > index 6510812..2afdb40 100644
> > --- a/drivers/pwm/pwm-berlin.c
> > +++ b/drivers/pwm/pwm-berlin.c
> > @@ -27,10 +27,20 @@
> >  #define BERLIN_PWM_TCNT			0xc
> >  #define  BERLIN_PWM_MAX_TCNT		65535
> >  
> > +#define NUM_PWM_CHANNEL			4	/* berlin PWM channels */
> > +
> > +struct berlin_pwm_context {
> > +	u32	enable;
> > +	u32	ctrl;
> > +	u32	duty;
> > +	u32	tcnt;
> > +};
> > +
> >  struct berlin_pwm_chip {
> >  	struct pwm_chip chip;
> >  	struct clk *clk;
> >  	void __iomem *base;
> > +	struct berlin_pwm_context ctx[NUM_PWM_CHANNEL];  
> 
> Please don't do this. You can easily attach per-PWM data using the
> pwm_set_chip_data() function and retrieve it using pwm_get_chip_data().

Got it. Will do in v2.

> 
> >  };
> >  
> >  static inline struct berlin_pwm_chip *to_berlin_pwm_chip(struct pwm_chip *chip)
> > @@ -176,7 +186,7 @@ static int berlin_pwm_probe(struct platform_device *pdev)
> >  	pwm->chip.dev = &pdev->dev;
> >  	pwm->chip.ops = &berlin_pwm_ops;
> >  	pwm->chip.base = -1;
> > -	pwm->chip.npwm = 4;
> > +	pwm->chip.npwm = NUM_PWM_CHANNEL;
> >  	pwm->chip.can_sleep = true;
> >  	pwm->chip.of_xlate = of_pwm_xlate_with_flags;
> >  	pwm->chip.of_pwm_n_cells = 3;
> > @@ -204,12 +214,57 @@ static int berlin_pwm_remove(struct platform_device *pdev)
> >  	return ret;
> >  }
> >  
> > +#ifdef CONFIG_PM_SLEEP
> > +static int berlin_pwm_suspend(struct device *dev)
> > +{
> > +	int i;  
> 
> unsigned int, please.

will do in v2. 

> 
> > +	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
> > +
> > +	for (i = 0; i < pwm->chip.npwm; i++) {
> > +		struct berlin_pwm_context *ctx = &pwm->ctx[i];
> > +
> > +		ctx->enable = berlin_pwm_readl(pwm, i, BERLIN_PWM_ENABLE);
> > +		ctx->ctrl = berlin_pwm_readl(pwm, i, BERLIN_PWM_CONTROL);
> > +		ctx->duty = berlin_pwm_readl(pwm, i, BERLIN_PWM_DUTY);
> > +		ctx->tcnt = berlin_pwm_readl(pwm, i, BERLIN_PWM_TCNT);
> > +	}
> > +	clk_disable_unprepare(pwm->clk);
> > +
> > +	return 0;
> > +}
> > +
> > +static int berlin_pwm_resume(struct device *dev)
> > +{
> > +	int i;  
> 
> unsigned int, please.

will do

> 
> > +	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
> > +
> > +	clk_prepare_enable(pwm->clk);  
> 
> Always check the return value of this function.

oops, thanks for pointing out this. Will do in v2.

> 
> > +	for (i = 0; i < pwm->chip.npwm; i++) {
> > +		struct berlin_pwm_context *ctx = &pwm->ctx[i];
> > +
> > +		berlin_pwm_writel(pwm, i, ctx->ctrl, BERLIN_PWM_CONTROL);
> > +		berlin_pwm_writel(pwm, i, ctx->duty, BERLIN_PWM_DUTY);
> > +		berlin_pwm_writel(pwm, i, ctx->tcnt, BERLIN_PWM_TCNT);
> > +		berlin_pwm_writel(pwm, i, ctx->enable, BERLIN_PWM_ENABLE);
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend,
> > +			 berlin_pwm_resume);
> > +#define BERLIN_PWM_PM_OPS	(&berlin_pwm_pm_ops)
> > +#else
> > +#define BERLIN_PWM_PM_OPS	NULL
> > +#endif  
> 
> This is a weird way of writing this. I think a more typical way would be
> to have the #ifdef contain only the implementation and then define the
> dev_pm_ops variable unconditonally, so you don't need a separate macro
> for it.
> 

The reason why I introduced one more macro is: struct dev_pm_ops contains
23 pointers now, if there's no BERLIN_PWM_PM_OPS macro, there will be always a
dev_pm_ops even if PM_SLEEP isn't enabled. I dunno whether there's any
elegant solution for this case.

How about define SIMPLE_DEV_PM_OPS as NULL if PM_SLEEP isn't enabled?

Thanks,
Jisheng

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]

#1277457

[Multipart message — attachments visible in raw view] — view raw

On Wed, Nov 25, 2015 at 04:30:19PM +0800, Jisheng Zhang wrote:
> On Tue, 24 Nov 2015 17:23:06 +0100 Thierry Reding wrote:
> > On Tue, Nov 24, 2015 at 01:43:05PM +0800, Jisheng Zhang wrote:
> > > This patch adds S2R support for berlin pwm driver.
> > > 
> > > Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> > > ---
> > >  drivers/pwm/pwm-berlin.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++-
> > >  1 file changed, 56 insertions(+), 1 deletion(-)
[...]
> > > +	for (i = 0; i < pwm->chip.npwm; i++) {
> > > +		struct berlin_pwm_context *ctx = &pwm->ctx[i];
> > > +
> > > +		berlin_pwm_writel(pwm, i, ctx->ctrl, BERLIN_PWM_CONTROL);
> > > +		berlin_pwm_writel(pwm, i, ctx->duty, BERLIN_PWM_DUTY);
> > > +		berlin_pwm_writel(pwm, i, ctx->tcnt, BERLIN_PWM_TCNT);
> > > +		berlin_pwm_writel(pwm, i, ctx->enable, BERLIN_PWM_ENABLE);
> > > +	}
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend,
> > > +			 berlin_pwm_resume);
> > > +#define BERLIN_PWM_PM_OPS	(&berlin_pwm_pm_ops)
> > > +#else
> > > +#define BERLIN_PWM_PM_OPS	NULL
> > > +#endif  
> > 
> > This is a weird way of writing this. I think a more typical way would be
> > to have the #ifdef contain only the implementation and then define the
> > dev_pm_ops variable unconditonally, so you don't need a separate macro
> > for it.
> > 
> 
> The reason why I introduced one more macro is: struct dev_pm_ops contains
> 23 pointers now, if there's no BERLIN_PWM_PM_OPS macro, there will be always a
> dev_pm_ops even if PM_SLEEP isn't enabled. I dunno whether there's any
> elegant solution for this case.

I wouldn't bother. PM_SLEEP is in almost all cases going to be enabled.
If it isn't enabled it's likely going to be in test builds, at which
point nobody will care about the extra 23 pointers.

> How about define SIMPLE_DEV_PM_OPS as NULL if PM_SLEEP isn't enabled?

That won't work, "static NULL;" wouldn't be valid syntax. Like I said,
if you go through the trouble of implementing suspend/resume, you're
almost certainly going to want to enable it, so just define it
unconditionally.

Thierry

[toc] | [prev] | [next] | [standalone]

#1278029

On Wed, 25 Nov 2015 16:16:27 +0100
Thierry Reding wrote:

> On Wed, Nov 25, 2015 at 04:30:19PM +0800, Jisheng Zhang wrote:
> > On Tue, 24 Nov 2015 17:23:06 +0100 Thierry Reding wrote:  
> > > On Tue, Nov 24, 2015 at 01:43:05PM +0800, Jisheng Zhang wrote:  
> > > > This patch adds S2R support for berlin pwm driver.
> > > > 
> > > > Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> > > > ---
> > > >  drivers/pwm/pwm-berlin.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++-
> > > >  1 file changed, 56 insertions(+), 1 deletion(-)  
> [...]
> > > > +	for (i = 0; i < pwm->chip.npwm; i++) {
> > > > +		struct berlin_pwm_context *ctx = &pwm->ctx[i];
> > > > +
> > > > +		berlin_pwm_writel(pwm, i, ctx->ctrl, BERLIN_PWM_CONTROL);
> > > > +		berlin_pwm_writel(pwm, i, ctx->duty, BERLIN_PWM_DUTY);
> > > > +		berlin_pwm_writel(pwm, i, ctx->tcnt, BERLIN_PWM_TCNT);
> > > > +		berlin_pwm_writel(pwm, i, ctx->enable, BERLIN_PWM_ENABLE);
> > > > +	}
> > > > +
> > > > +	return 0;
> > > > +}
> > > > +
> > > > +static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend,
> > > > +			 berlin_pwm_resume);
> > > > +#define BERLIN_PWM_PM_OPS	(&berlin_pwm_pm_ops)
> > > > +#else
> > > > +#define BERLIN_PWM_PM_OPS	NULL
> > > > +#endif    
> > > 
> > > This is a weird way of writing this. I think a more typical way would be
> > > to have the #ifdef contain only the implementation and then define the
> > > dev_pm_ops variable unconditonally, so you don't need a separate macro
> > > for it.
> > >   
> > 
> > The reason why I introduced one more macro is: struct dev_pm_ops contains
> > 23 pointers now, if there's no BERLIN_PWM_PM_OPS macro, there will be always a
> > dev_pm_ops even if PM_SLEEP isn't enabled. I dunno whether there's any
> > elegant solution for this case.  
> 
> I wouldn't bother. PM_SLEEP is in almost all cases going to be enabled.
> If it isn't enabled it's likely going to be in test builds, at which
> point nobody will care about the extra 23 pointers.
> 
> > How about define SIMPLE_DEV_PM_OPS as NULL if PM_SLEEP isn't enabled?  
> 
> That won't work, "static NULL;" wouldn't be valid syntax. Like I said,
> if you go through the trouble of implementing suspend/resume, you're
> almost certainly going to want to enable it, so just define it
> unconditionally.
> 

Thanks for detailed explanation. In yesterday's v2, the BERLIN_PWM_PM_OPS
was removed.

Thanks for review,
Jisheng
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web