[PATCH v4 00/24] pwm: add support for atomic update

[PATCH v4 00/24] pwm: add support for atomic update

[Boris Brezillon]

Hello,

This series adds support for atomic PWM update, or IOW, the capability
to update all the parameters of a PWM device (enabled/disabled, period,
duty and polarity) in one go.

Best Regards,

Boris

Changes since v3:
- rebased on pwm/for-next after pulling 4.4-rc1
- replace direct access to pwm fields by pwm_get/set_xxx() helpers, thus
  fixing some build errors
- split changes to allow each maintainer to review/ack or take the
  modification through its subsystem

Changes since v2:
- rebased on top of 4.3-rc2
- reintroduced pwm-regulator patches

Changes since v1:
- dropped applied patches
- squashed Heiko's fixes into the rockchip driver changes
- made a few cosmetic changes
- added kerneldoc comments
- added Heiko's patch to display more information in debugfs
- dropped pwm-regulator patches (should be submitted separately)

Boris Brezillon (23):
  pwm: rcar: make use of pwm_is_enabled()
  pwm: use pwm_get_xxx() helpers where appropriate
  clk: pwm: use pwm_get_xxx() helpers where appropriate
  hwmon: pwm-fan: use pwm_get_xxx() helpers where appropriate
  misc: max77693-haptic: use pwm_get_xxx() helpers where appropriate
  pwm: introduce default period and polarity concepts
  pwm: use pwm_get/set_default_xxx() helpers where appropriate
  leds: pwm: use pwm_get/set_default_xxx() helpers where appropriate
  regulator: pwm: use pwm_get/set_default_xxx() helpers where
    appropriate
  backlight: pwm: use pwm_get/set_default_xxx() helpers where
    appropriate
  fbdev: use pwm_get/set_default_xxx() helpers where appropriate
  misc: max77693: use pwm_get/set_default_xxx() helpers where
    appropriate
  hwmon: pwm-fan: use pwm_get/set_default_xxx() helpers where
    appropriate
  clk: pwm: use pwm_get/set_default_xxx() helpers where appropriate
  pwm: define a new pwm_state struct
  pwm: move the enabled/disabled info to pwm_state struct
  backlight: pwm_bl: remove useless call to pwm_set_period
  pwm: declare a default PWM state
  pwm: add the PWM initial state retrieval infra
  pwm: add the core infrastructure to allow atomic update
  pwm: rockchip: add initial state retrieval
  pwm: rockchip: add support for atomic update
  regulator: pwm: properly initialize the ->state field

Heiko Stübner (1):
  pwm: add information about polarity, duty cycle and period to debugfs

 drivers/clk/clk-pwm.c                |  11 +--
 drivers/hwmon/pwm-fan.c              |  16 ++--
 drivers/input/misc/max77693-haptic.c |   9 +-
 drivers/leds/leds-pwm.c              |   2 +-
 drivers/pwm/core.c                   | 169 +++++++++++++++++++++++++++++++----
 drivers/pwm/pwm-crc.c                |   2 +-
 drivers/pwm/pwm-lpc18xx-sct.c        |   2 +-
 drivers/pwm/pwm-pxa.c                |   2 +-
 drivers/pwm/pwm-rcar.c               |   2 +-
 drivers/pwm/pwm-rockchip.c           | 119 +++++++++++++++++++-----
 drivers/pwm/pwm-sun4i.c              |   3 +-
 drivers/regulator/pwm-regulator.c    |  30 ++++++-
 drivers/video/backlight/lm3630a_bl.c |   4 +-
 drivers/video/backlight/pwm_bl.c     |  10 ++-
 drivers/video/fbdev/ssd1307fb.c      |   2 +-
 include/linux/pwm.h                  |  89 +++++++++++++++---
 16 files changed, 386 insertions(+), 86 deletions(-)

-- 
2.1.4

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[PATCH v4 01/24] pwm: rcar: make use of pwm_is_enabled()

[Boris Brezillon]

Commit 5c31252c4a86 ("pwm: Add the pwm_is_enabled() helper") introduced a
new function to test whether a PWM device is enabled or not without
manipulating PWM internal fields.
Hiding this is necessary if we want to smoothly move to the atomic PWM
config approach without impacting PWM drivers.
Fix this driver to use pwm_is_enabled() instead of directly accessing the
->flags field.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
 drivers/pwm/pwm-rcar.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c
index 6e99a63..70899c9 100644
--- a/drivers/pwm/pwm-rcar.c
+++ b/drivers/pwm/pwm-rcar.c
@@ -157,7 +157,7 @@ static int rcar_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		return div;
 
 	/* Let the core driver set pwm->period if disabled and duty_ns == 0 */
-	if (!test_bit(PWMF_ENABLED, &pwm->flags) && !duty_ns)
+	if (!pwm_is_enabled(pwm) && !duty_ns)
 		return 0;
 
 	rcar_pwm_update(rp, RCAR_PWMCR_SYNC, RCAR_PWMCR_SYNC, RCAR_PWMCR);
-- 
2.1.4

Re: [PATCH v4 01/24] pwm: rcar: make use of pwm_is_enabled()

[Boris Brezillon]

Hi Thierry,

Can you please apply this patch?
It's completely independent from the rest of the series.

Thanks,

Boris

On Mon, 16 Nov 2015 09:56:24 +0100
Boris Brezillon <boris.brezillon@free-electrons.com> wrote:

> Commit 5c31252c4a86 ("pwm: Add the pwm_is_enabled() helper") introduced a
> new function to test whether a PWM device is enabled or not without
> manipulating PWM internal fields.
> Hiding this is necessary if we want to smoothly move to the atomic PWM
> config approach without impacting PWM drivers.
> Fix this driver to use pwm_is_enabled() instead of directly accessing the
> ->flags field.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> ---
>  drivers/pwm/pwm-rcar.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c
> index 6e99a63..70899c9 100644
> --- a/drivers/pwm/pwm-rcar.c
> +++ b/drivers/pwm/pwm-rcar.c
> @@ -157,7 +157,7 @@ static int rcar_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>  		return div;
>  
>  	/* Let the core driver set pwm->period if disabled and duty_ns == 0 */
> -	if (!test_bit(PWMF_ENABLED, &pwm->flags) && !duty_ns)
> +	if (!pwm_is_enabled(pwm) && !duty_ns)
>  		return 0;
>  
>  	rcar_pwm_update(rp, RCAR_PWMCR_SYNC, RCAR_PWMCR_SYNC, RCAR_PWMCR);



-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[PATCH v4 02/24] pwm: use pwm_get_xxx() helpers where appropriate

[Boris Brezillon]

Use pwm_get_xxx() helpers instead of directly accessing the pwm->xxx field.
Doing that will ease adaptation of the PWM framework to support atomic
update.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
Patch generated with the following coccinelle script:

--->8---
virtual patch

@@
struct pwm_device *p;
expression e;
@@
(
-(p)->polarity = e;
+pwm_set_polarity((p), e);
|
-(p)->polarity
+pwm_get_polarity((p))
|
-(p)->period = e;
+pwm_set_period((p), e);
|
-(p)->period
+pwm_get_period((p))
|
-(p)->duty_cycle = e;
+pwm_set_duty_cycle((p), e);
|
-(p)->duty_cycle
+pwm_get_duty_cycle((p))
)
--->8---
---
 drivers/pwm/pwm-crc.c         | 2 +-
 drivers/pwm/pwm-lpc18xx-sct.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c
index 7101c70..2f88543 100644
--- a/drivers/pwm/pwm-crc.c
+++ b/drivers/pwm/pwm-crc.c
@@ -75,7 +75,7 @@ static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm,
 		return -EINVAL;
 	}
 
-	if (pwm->period != period_ns) {
+	if (pwm_get_period((pwm)) != period_ns) {
 		int clk_div;
 
 		/* changing the clk divisor, need to disable fisrt */
diff --git a/drivers/pwm/pwm-lpc18xx-sct.c b/drivers/pwm/pwm-lpc18xx-sct.c
index 9163085..091fa13 100644
--- a/drivers/pwm/pwm-lpc18xx-sct.c
+++ b/drivers/pwm/pwm-lpc18xx-sct.c
@@ -249,7 +249,7 @@ static int lpc18xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 			   LPC18XX_PWM_EVSTATEMSK(lpc18xx_data->duty_event),
 			   LPC18XX_PWM_EVSTATEMSK_ALL);
 
-	if (pwm->polarity == PWM_POLARITY_NORMAL) {
+	if (pwm_get_polarity((pwm)) == PWM_POLARITY_NORMAL) {
 		set_event = lpc18xx_pwm->period_event;
 		clear_event = lpc18xx_data->duty_event;
 		res_action = LPC18XX_PWM_RES_SET;
-- 
2.1.4

Re: [PATCH v4 02/24] pwm: use pwm_get_xxx() helpers where appropriate

[Joachim Eastwood]

Hi Boris

(Adding Ariel for pwm-lpc18xx-sct)

On 16 November 2015 at 09:56, Boris Brezillon
<boris.brezillon@free-electrons.com> wrote:
> Use pwm_get_xxx() helpers instead of directly accessing the pwm->xxx field.
> Doing that will ease adaptation of the PWM framework to support atomic
> update.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> ---
> Patch generated with the following coccinelle script:
>
> --->8---
> virtual patch
>
> @@
> struct pwm_device *p;
> expression e;
> @@
> (
> -(p)->polarity = e;
> +pwm_set_polarity((p), e);
> |
> -(p)->polarity
> +pwm_get_polarity((p))
> |
> -(p)->period = e;
> +pwm_set_period((p), e);
> |
> -(p)->period
> +pwm_get_period((p))
> |
> -(p)->duty_cycle = e;
> +pwm_set_duty_cycle((p), e);
> |
> -(p)->duty_cycle
> +pwm_get_duty_cycle((p))
> )
> --->8---
> ---
>  drivers/pwm/pwm-crc.c         | 2 +-
>  drivers/pwm/pwm-lpc18xx-sct.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c
> index 7101c70..2f88543 100644
> --- a/drivers/pwm/pwm-crc.c
> +++ b/drivers/pwm/pwm-crc.c
> @@ -75,7 +75,7 @@ static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm,
>                 return -EINVAL;
>         }
>
> -       if (pwm->period != period_ns) {
> +       if (pwm_get_period((pwm)) != period_ns) {
>                 int clk_div;
>
>                 /* changing the clk divisor, need to disable fisrt */
> diff --git a/drivers/pwm/pwm-lpc18xx-sct.c b/drivers/pwm/pwm-lpc18xx-sct.c
> index 9163085..091fa13 100644
> --- a/drivers/pwm/pwm-lpc18xx-sct.c
> +++ b/drivers/pwm/pwm-lpc18xx-sct.c
> @@ -249,7 +249,7 @@ static int lpc18xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
>                            LPC18XX_PWM_EVSTATEMSK(lpc18xx_data->duty_event),
>                            LPC18XX_PWM_EVSTATEMSK_ALL);
>
> -       if (pwm->polarity == PWM_POLARITY_NORMAL) {
> +       if (pwm_get_polarity((pwm)) == PWM_POLARITY_NORMAL) {

What is the deal with the double parentheses?

Think I saw that in some of the other patches as well.


regards,
Joachim Eastwood

Re: [PATCH v4 02/24] pwm: use pwm_get_xxx() helpers where appropriate

[Boris Brezillon]

Hi Joachim,

On Mon, 16 Nov 2015 18:46:44 +0100
Joachim  Eastwood <manabian@gmail.com> wrote:

> Hi Boris
> 
> (Adding Ariel for pwm-lpc18xx-sct)
> 
> On 16 November 2015 at 09:56, Boris Brezillon
> <boris.brezillon@free-electrons.com> wrote:
> > Use pwm_get_xxx() helpers instead of directly accessing the pwm->xxx field.
> > Doing that will ease adaptation of the PWM framework to support atomic
> > update.
> >
> > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> > ---
> > Patch generated with the following coccinelle script:
> >
> > --->8---
> > virtual patch
> >
> > @@
> > struct pwm_device *p;
> > expression e;
> > @@
> > (
> > -(p)->polarity = e;
> > +pwm_set_polarity((p), e);
> > |
> > -(p)->polarity
> > +pwm_get_polarity((p))
> > |
> > -(p)->period = e;
> > +pwm_set_period((p), e);
> > |
> > -(p)->period
> > +pwm_get_period((p))
> > |
> > -(p)->duty_cycle = e;
> > +pwm_set_duty_cycle((p), e);
> > |
> > -(p)->duty_cycle
> > +pwm_get_duty_cycle((p))
> > )
> > --->8---
> > ---
> >  drivers/pwm/pwm-crc.c         | 2 +-
> >  drivers/pwm/pwm-lpc18xx-sct.c | 2 +-
> >  2 files changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c
> > index 7101c70..2f88543 100644
> > --- a/drivers/pwm/pwm-crc.c
> > +++ b/drivers/pwm/pwm-crc.c
> > @@ -75,7 +75,7 @@ static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm,
> >                 return -EINVAL;
> >         }
> >
> > -       if (pwm->period != period_ns) {
> > +       if (pwm_get_period((pwm)) != period_ns) {
> >                 int clk_div;
> >
> >                 /* changing the clk divisor, need to disable fisrt */
> > diff --git a/drivers/pwm/pwm-lpc18xx-sct.c b/drivers/pwm/pwm-lpc18xx-sct.c
> > index 9163085..091fa13 100644
> > --- a/drivers/pwm/pwm-lpc18xx-sct.c
> > +++ b/drivers/pwm/pwm-lpc18xx-sct.c
> > @@ -249,7 +249,7 @@ static int lpc18xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
> >                            LPC18XX_PWM_EVSTATEMSK(lpc18xx_data->duty_event),
> >                            LPC18XX_PWM_EVSTATEMSK_ALL);
> >
> > -       if (pwm->polarity == PWM_POLARITY_NORMAL) {
> > +       if (pwm_get_polarity((pwm)) == PWM_POLARITY_NORMAL) {
> 
> What is the deal with the double parentheses?
> 
> Think I saw that in some of the other patches as well.

It comes from a typo in my coccinelle script. I already fixed it and
regenerated the faulty patches, so please ignore this aspect while
reviewing (this will be addressed in the next version).

Thanks,

Boris

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[PATCH v4 03/24] clk: pwm: use pwm_get_xxx() helpers where appropriate

[Boris Brezillon]

Use pwm_get_xxx() helpers instead of directly accessing the pwm->xxx field.
Doing that will ease adaptation of the PWM framework to support atomic
update.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
Patch generated with the following coccinelle script:

--->8---
virtual patch

@@
struct pwm_device *p;
expression e;
@@
(
-(p)->polarity = e;
+pwm_set_polarity((p), e);
|
-(p)->polarity
+pwm_get_polarity((p))
|
-(p)->period = e;
+pwm_set_period((p), e);
|
-(p)->period
+pwm_get_period((p))
|
-(p)->duty_cycle = e;
+pwm_set_duty_cycle((p), e);
|
-(p)->duty_cycle
+pwm_get_duty_cycle((p))
)
--->8---
---
 drivers/clk/clk-pwm.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/clk/clk-pwm.c b/drivers/clk/clk-pwm.c
index 328fcfc..b6306a2 100644
--- a/drivers/clk/clk-pwm.c
+++ b/drivers/clk/clk-pwm.c
@@ -71,22 +71,23 @@ static int clk_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(pwm))
 		return PTR_ERR(pwm);
 
-	if (!pwm->period) {
+	if (!pwm_get_period((pwm))) {
 		dev_err(&pdev->dev, "invalid PWM period\n");
 		return -EINVAL;
 	}
 
 	if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate))
-		clk_pwm->fixed_rate = NSEC_PER_SEC / pwm->period;
+		clk_pwm->fixed_rate = NSEC_PER_SEC / pwm_get_period((pwm));
 
-	if (pwm->period != NSEC_PER_SEC / clk_pwm->fixed_rate &&
-	    pwm->period != DIV_ROUND_UP(NSEC_PER_SEC, clk_pwm->fixed_rate)) {
+	if (pwm_get_period((pwm)) != NSEC_PER_SEC / clk_pwm->fixed_rate &&
+	    pwm_get_period((pwm)) != DIV_ROUND_UP(NSEC_PER_SEC, clk_pwm->fixed_rate)) {
 		dev_err(&pdev->dev,
 			"clock-frequency does not match PWM period\n");
 		return -EINVAL;
 	}
 
-	ret = pwm_config(pwm, (pwm->period + 1) >> 1, pwm->period);
+	ret = pwm_config(pwm, (pwm_get_period((pwm)) + 1) >> 1,
+			 pwm_get_period((pwm)));
 	if (ret < 0)
 		return ret;
 
-- 
2.1.4

Re: [PATCH v4 03/24] clk: pwm: use pwm_get_xxx() helpers where appropriate

[Michael Turquette]

Hi Boris,

Quoting Boris Brezillon (2015-11-16 00:56:26)
> diff --git a/drivers/clk/clk-pwm.c b/drivers/clk/clk-pwm.c
> index 328fcfc..b6306a2 100644
> --- a/drivers/clk/clk-pwm.c
> +++ b/drivers/clk/clk-pwm.c
> @@ -71,22 +71,23 @@ static int clk_pwm_probe(struct platform_device *pdev)
>         if (IS_ERR(pwm))
>                 return PTR_ERR(pwm);
>  
> -       if (!pwm->period) {
> +       if (!pwm_get_period((pwm))) {

The change itself looks fine, but the semantic patch added extra parens.
Can you remove them? After doing so feel free to add:

Acked-by: Michael Turquette <mturquette-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>

[PATCH v4 04/24] hwmon: pwm-fan: use pwm_get_xxx() helpers where appropriate

[Boris Brezillon]

Use pwm_get_xxx() helpers instead of directly accessing the pwm->xxx field.
Doing that will ease adaptation of the PWM framework to support atomic
update.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
Patch generated with the following coccinelle script:

--->8---
virtual patch

@@
struct pwm_device *p;
expression e;
@@
(
-(p)->polarity = e;
+pwm_set_polarity((p), e);
|
-(p)->polarity
+pwm_get_polarity((p))
|
-(p)->period = e;
+pwm_set_period((p), e);
|
-(p)->period
+pwm_get_period((p))
|
-(p)->duty_cycle = e;
+pwm_set_duty_cycle((p), e);
|
-(p)->duty_cycle
+pwm_get_duty_cycle((p))
)
--->8---
---
 drivers/hwmon/pwm-fan.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 3e23003..105b964 100644
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -47,8 +47,8 @@ static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
 	if (ctx->pwm_value == pwm)
 		goto exit_set_pwm_err;
 
-	duty = DIV_ROUND_UP(pwm * (ctx->pwm->period - 1), MAX_PWM);
-	ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
+	duty = DIV_ROUND_UP(pwm * (pwm_get_period((ctx->pwm)) - 1), MAX_PWM);
+	ret = pwm_config(ctx->pwm, duty, pwm_get_period((ctx->pwm)));
 	if (ret)
 		goto exit_set_pwm_err;
 
@@ -234,10 +234,10 @@ static int pwm_fan_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, ctx);
 
 	/* Set duty cycle to maximum allowed */
-	duty_cycle = ctx->pwm->period - 1;
+	duty_cycle = pwm_get_period((ctx->pwm)) - 1;
 	ctx->pwm_value = MAX_PWM;
 
-	ret = pwm_config(ctx->pwm, duty_cycle, ctx->pwm->period);
+	ret = pwm_config(ctx->pwm, duty_cycle, pwm_get_period((ctx->pwm)));
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to configure PWM\n");
 		return ret;
@@ -309,8 +309,9 @@ static int pwm_fan_resume(struct device *dev)
 	if (ctx->pwm_value == 0)
 		return 0;
 
-	duty = DIV_ROUND_UP(ctx->pwm_value * (ctx->pwm->period - 1), MAX_PWM);
-	ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
+	duty = DIV_ROUND_UP(ctx->pwm_value * (pwm_get_period((ctx->pwm)) - 1),
+			    MAX_PWM);
+	ret = pwm_config(ctx->pwm, duty, pwm_get_period((ctx->pwm)));
 	if (ret)
 		return ret;
 	return pwm_enable(ctx->pwm);
-- 
2.1.4

Re: [PATCH v4 04/24] hwmon: pwm-fan: use pwm_get_xxx() helpers where appropriate

[Guenter Roeck]

On 11/16/2015 12:56 AM, Boris Brezillon wrote:
> Use pwm_get_xxx() helpers instead of directly accessing the pwm->xxx field.
> Doing that will ease adaptation of the PWM framework to support atomic
> update.
>
> Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
> ---
> Patch generated with the following coccinelle script:
>
> --->8---
> virtual patch
>
> @@
> struct pwm_device *p;
> expression e;
> @@
> (
> -(p)->polarity = e;
> +pwm_set_polarity((p), e);
> |
> -(p)->polarity
> +pwm_get_polarity((p))

s/((p))/(p)/

> |
> -(p)->period = e;
> +pwm_set_period((p), e);
> |
> -(p)->period
> +pwm_get_period((p))

s/((p))/(p)/

> |
> -(p)->duty_cycle = e;
> +pwm_set_duty_cycle((p), e);

The (p) seems unnecessary here.

> |
> -(p)->duty_cycle
> +pwm_get_duty_cycle((p))

s/((p))/(p)/

> )
> --->8---
> ---
>   drivers/hwmon/pwm-fan.c | 13 +++++++------
>   1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
> index 3e23003..105b964 100644
> --- a/drivers/hwmon/pwm-fan.c
> +++ b/drivers/hwmon/pwm-fan.c
> @@ -47,8 +47,8 @@ static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
>   	if (ctx->pwm_value == pwm)
>   		goto exit_set_pwm_err;
>
> -	duty = DIV_ROUND_UP(pwm * (ctx->pwm->period - 1), MAX_PWM);
> -	ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
> +	duty = DIV_ROUND_UP(pwm * (pwm_get_period((ctx->pwm)) - 1), MAX_PWM);
> +	ret = pwm_config(ctx->pwm, duty, pwm_get_period((ctx->pwm)));

Please drop all the unnecessary ( ).

Thanks,
Guenter

>   	if (ret)
>   		goto exit_set_pwm_err;
>
> @@ -234,10 +234,10 @@ static int pwm_fan_probe(struct platform_device *pdev)
>   	platform_set_drvdata(pdev, ctx);
>
>   	/* Set duty cycle to maximum allowed */
> -	duty_cycle = ctx->pwm->period - 1;
> +	duty_cycle = pwm_get_period((ctx->pwm)) - 1;
>   	ctx->pwm_value = MAX_PWM;
>
> -	ret = pwm_config(ctx->pwm, duty_cycle, ctx->pwm->period);
> +	ret = pwm_config(ctx->pwm, duty_cycle, pwm_get_period((ctx->pwm)));
>   	if (ret) {
>   		dev_err(&pdev->dev, "Failed to configure PWM\n");
>   		return ret;
> @@ -309,8 +309,9 @@ static int pwm_fan_resume(struct device *dev)
>   	if (ctx->pwm_value == 0)
>   		return 0;
>
> -	duty = DIV_ROUND_UP(ctx->pwm_value * (ctx->pwm->period - 1), MAX_PWM);
> -	ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
> +	duty = DIV_ROUND_UP(ctx->pwm_value * (pwm_get_period((ctx->pwm)) - 1),
> +			    MAX_PWM);
> +	ret = pwm_config(ctx->pwm, duty, pwm_get_period((ctx->pwm)));
>   	if (ret)
>   		return ret;
>   	return pwm_enable(ctx->pwm);
>

Re: [PATCH v4 04/24] hwmon: pwm-fan: use pwm_get_xxx() helpers where appropriate

[Boris Brezillon]

On Mon, 16 Nov 2015 07:59:23 -0800
Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> wrote:

> On 11/16/2015 12:56 AM, Boris Brezillon wrote:
> > Use pwm_get_xxx() helpers instead of directly accessing the pwm->xxx field.
> > Doing that will ease adaptation of the PWM framework to support atomic
> > update.
> >
> > Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
> > ---
> > Patch generated with the following coccinelle script:
> >
> > --->8---
> > virtual patch
> >
> > @@
> > struct pwm_device *p;
> > expression e;
> > @@
> > (
> > -(p)->polarity = e;
> > +pwm_set_polarity((p), e);
> > |
> > -(p)->polarity
> > +pwm_get_polarity((p))
> 
> s/((p))/(p)/
> 
> > |
> > -(p)->period = e;
> > +pwm_set_period((p), e);
> > |
> > -(p)->period
> > +pwm_get_period((p))
> 
> s/((p))/(p)/
> 
> > |
> > -(p)->duty_cycle = e;
> > +pwm_set_duty_cycle((p), e);
> 
> The (p) seems unnecessary here.

I don't get this one. You mean I should drop one the parenthesis around
p, right?




-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Re: [PATCH v4 04/24] hwmon: pwm-fan: use pwm_get_xxx() helpers where appropriate

[Guenter Roeck]

On 11/16/2015 08:53 AM, Boris Brezillon wrote:
> On Mon, 16 Nov 2015 07:59:23 -0800
> Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> wrote:
>
>> On 11/16/2015 12:56 AM, Boris Brezillon wrote:
>>> Use pwm_get_xxx() helpers instead of directly accessing the pwm->xxx field.
>>> Doing that will ease adaptation of the PWM framework to support atomic
>>> update.
>>>
>>> Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
>>> ---
>>> Patch generated with the following coccinelle script:
>>>
>>> --->8---
>>> virtual patch
>>>
>>> @@
>>> struct pwm_device *p;
>>> expression e;
>>> @@
>>> (
>>> -(p)->polarity = e;
>>> +pwm_set_polarity((p), e);
>>> |
>>> -(p)->polarity
>>> +pwm_get_polarity((p))
>>
>> s/((p))/(p)/
>>
>>> |
>>> -(p)->period = e;
>>> +pwm_set_period((p), e);
>>> |
>>> -(p)->period
>>> +pwm_get_period((p))
>>
>> s/((p))/(p)/
>>
>>> |
>>> -(p)->duty_cycle = e;
>>> +pwm_set_duty_cycle((p), e);
>>
>> The (p) seems unnecessary here.
>
> I don't get this one. You mean I should drop one the parenthesis around
> p, right?
>

Same as above - s/(p)/p/. It should never be necessary to write
	pwm_set_duty_cycle((p), e)
since
	pwm_set_duty_cycle(p, e)
should be the same.

On the other side, I did not see this expression used in any of the patches,
though maybe I missed it.

Thanks,
Guenter

[PATCH v4 05/24] misc: max77693-haptic: use pwm_get_xxx() helpers where appropriate

[Boris Brezillon]

Use pwm_get_xxx() helpers instead of directly accessing the pwm->xxx field.
Doing that will ease adaptation of the PWM framework to support atomic
update.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
Patch generated with the following coccinelle script:

--->8---
virtual patch

@@
struct pwm_device *p;
expression e;
@@
(
-(p)->polarity = e;
+pwm_set_polarity((p), e);
|
-(p)->polarity
+pwm_get_polarity((p))
|
-(p)->period = e;
+pwm_set_period((p), e);
|
-(p)->period
+pwm_get_period((p))
|
-(p)->duty_cycle = e;
+pwm_set_duty_cycle((p), e);
|
-(p)->duty_cycle
+pwm_get_duty_cycle((p))
)
--->8---
---
 drivers/input/misc/max77693-haptic.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/input/misc/max77693-haptic.c b/drivers/input/misc/max77693-haptic.c
index 6d96bff..a038fb3 100644
--- a/drivers/input/misc/max77693-haptic.c
+++ b/drivers/input/misc/max77693-haptic.c
@@ -70,10 +70,11 @@ struct max77693_haptic {
 
 static int max77693_haptic_set_duty_cycle(struct max77693_haptic *haptic)
 {
-	int delta = (haptic->pwm_dev->period + haptic->pwm_duty) / 2;
+	int delta = (pwm_get_period((haptic->pwm_dev)) + haptic->pwm_duty) / 2;
 	int error;
 
-	error = pwm_config(haptic->pwm_dev, delta, haptic->pwm_dev->period);
+	error = pwm_config(haptic->pwm_dev, delta,
+			   pwm_get_period((haptic->pwm_dev)));
 	if (error) {
 		dev_err(haptic->dev, "failed to configure pwm: %d\n", error);
 		return error;
@@ -245,7 +246,7 @@ static int max77693_haptic_play_effect(struct input_dev *dev, void *data,
 	 * The formula to convert magnitude to pwm_duty as follows:
 	 * - pwm_duty = (magnitude * pwm_period) / MAX_MAGNITUDE(0xFFFF)
 	 */
-	period_mag_multi = (u64)haptic->pwm_dev->period * haptic->magnitude;
+	period_mag_multi = (u64)pwm_get_period((haptic->pwm_dev)) * haptic->magnitude;
 	haptic->pwm_duty = (unsigned int)(period_mag_multi >>
 						MAX_MAGNITUDE_SHIFT);
 
-- 
2.1.4

Re: [PATCH v4 05/24] misc: max77693-haptic: use pwm_get_xxx() helpers where appropriate

[Krzysztof Kozlowski]

W dniu 16.11.2015 o 17:56, Boris Brezillon pisze:
> Use pwm_get_xxx() helpers instead of directly accessing the pwm->xxx field.
> Doing that will ease adaptation of the PWM framework to support atomic
> update.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
> ---
> Patch generated with the following coccinelle script:
> 
> --->8---
> virtual patch
> 
> @@
> struct pwm_device *p;
> expression e;
> @@
> (
> -(p)->polarity = e;
> +pwm_set_polarity((p), e);
> |
> -(p)->polarity
> +pwm_get_polarity((p))
> |
> -(p)->period = e;
> +pwm_set_period((p), e);
> |
> -(p)->period
> +pwm_get_period((p))
> |
> -(p)->duty_cycle = e;
> +pwm_set_duty_cycle((p), e);
> |
> -(p)->duty_cycle
> +pwm_get_duty_cycle((p))
> )
> --->8---
> ---
>  drivers/input/misc/max77693-haptic.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/input/misc/max77693-haptic.c b/drivers/input/misc/max77693-haptic.c
> index 6d96bff..a038fb3 100644
> --- a/drivers/input/misc/max77693-haptic.c
> +++ b/drivers/input/misc/max77693-haptic.c
> @@ -70,10 +70,11 @@ struct max77693_haptic {
>  
>  static int max77693_haptic_set_duty_cycle(struct max77693_haptic *haptic)
>  {
> -	int delta = (haptic->pwm_dev->period + haptic->pwm_duty) / 2;
> +	int delta = (pwm_get_period((haptic->pwm_dev)) + haptic->pwm_duty) / 2;

Double parentheses over argument are not needed so just:
pwm_get_period(haptic->pwm_dev) + ...

Beside that patch looks good, so with removing parentheses here and below:

Reviewed-by: Krzysztof Kozlowski <k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>

Best regards,
Krzysztof

>  	int error;
>  
> -	error = pwm_config(haptic->pwm_dev, delta, haptic->pwm_dev->period);
> +	error = pwm_config(haptic->pwm_dev, delta,
> +			   pwm_get_period((haptic->pwm_dev)));
>  	if (error) {
>  		dev_err(haptic->dev, "failed to configure pwm: %d\n", error);
>  		return error;
> @@ -245,7 +246,7 @@ static int max77693_haptic_play_effect(struct input_dev *dev, void *data,
>  	 * The formula to convert magnitude to pwm_duty as follows:
>  	 * - pwm_duty = (magnitude * pwm_period) / MAX_MAGNITUDE(0xFFFF)
>  	 */
> -	period_mag_multi = (u64)haptic->pwm_dev->period * haptic->magnitude;
> +	period_mag_multi = (u64)pwm_get_period((haptic->pwm_dev)) * haptic->magnitude;
>  	haptic->pwm_duty = (unsigned int)(period_mag_multi >>
>  						MAX_MAGNITUDE_SHIFT);
>  
> 

Re: [PATCH v4 05/24] misc: max77693-haptic: use pwm_get_xxx() helpers where appropriate

[Boris Brezillon]

Hi Krzysztof,

On Mon, 16 Nov 2015 22:10:40 +0900
Krzysztof Kozlowski <k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org> wrote:

> W dniu 16.11.2015 o 17:56, Boris Brezillon pisze:
> > Use pwm_get_xxx() helpers instead of directly accessing the pwm->xxx field.
> > Doing that will ease adaptation of the PWM framework to support atomic
> > update.
> > 
> > Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
> > ---
> > Patch generated with the following coccinelle script:
> > 
> > --->8---
> > virtual patch
> > 
> > @@
> > struct pwm_device *p;
> > expression e;
> > @@
> > (
> > -(p)->polarity = e;
> > +pwm_set_polarity((p), e);
> > |
> > -(p)->polarity
> > +pwm_get_polarity((p))
> > |
> > -(p)->period = e;
> > +pwm_set_period((p), e);
> > |
> > -(p)->period
> > +pwm_get_period((p))
> > |
> > -(p)->duty_cycle = e;
> > +pwm_set_duty_cycle((p), e);
> > |
> > -(p)->duty_cycle
> > +pwm_get_duty_cycle((p))
> > )
> > --->8---
> > ---
> >  drivers/input/misc/max77693-haptic.c | 7 ++++---
> >  1 file changed, 4 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/input/misc/max77693-haptic.c b/drivers/input/misc/max77693-haptic.c
> > index 6d96bff..a038fb3 100644
> > --- a/drivers/input/misc/max77693-haptic.c
> > +++ b/drivers/input/misc/max77693-haptic.c
> > @@ -70,10 +70,11 @@ struct max77693_haptic {
> >  
> >  static int max77693_haptic_set_duty_cycle(struct max77693_haptic *haptic)
> >  {
> > -	int delta = (haptic->pwm_dev->period + haptic->pwm_duty) / 2;
> > +	int delta = (pwm_get_period((haptic->pwm_dev)) + haptic->pwm_duty) / 2;
> 
> Double parentheses over argument are not needed so just:
> pwm_get_period(haptic->pwm_dev) + ...

Actually it was generated with coccinelle, hence I didn't fix existing
coding style issues, but I have no problem fixing them.

Thanks,

Boris

> 
> Beside that patch looks good, so with removing parentheses here and below:
> 
> Reviewed-by: Krzysztof Kozlowski <k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> 
> Best regards,
> Krzysztof
> 
> >  	int error;
> >  
> > -	error = pwm_config(haptic->pwm_dev, delta, haptic->pwm_dev->period);
> > +	error = pwm_config(haptic->pwm_dev, delta,
> > +			   pwm_get_period((haptic->pwm_dev)));
> >  	if (error) {
> >  		dev_err(haptic->dev, "failed to configure pwm: %d\n", error);
> >  		return error;
> > @@ -245,7 +246,7 @@ static int max77693_haptic_play_effect(struct input_dev *dev, void *data,
> >  	 * The formula to convert magnitude to pwm_duty as follows:
> >  	 * - pwm_duty = (magnitude * pwm_period) / MAX_MAGNITUDE(0xFFFF)
> >  	 */
> > -	period_mag_multi = (u64)haptic->pwm_dev->period * haptic->magnitude;
> > +	period_mag_multi = (u64)pwm_get_period((haptic->pwm_dev)) * haptic->magnitude;
> >  	haptic->pwm_duty = (unsigned int)(period_mag_multi >>
> >  						MAX_MAGNITUDE_SHIFT);
> >  
> > 
> 



-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Re: [PATCH v4 05/24] misc: max77693-haptic: use pwm_get_xxx() helpers where appropriate

[Guenter Roeck]

On 11/16/2015 05:55 AM, Boris Brezillon wrote:
> Hi Krzysztof,
>
> On Mon, 16 Nov 2015 22:10:40 +0900
> Krzysztof Kozlowski <k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org> wrote:
>
>> W dniu 16.11.2015 o 17:56, Boris Brezillon pisze:
>>> Use pwm_get_xxx() helpers instead of directly accessing the pwm->xxx field.
>>> Doing that will ease adaptation of the PWM framework to support atomic
>>> update.
>>>
>>> Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
>>> ---
>>> Patch generated with the following coccinelle script:
>>>
>>> --->8---
>>> virtual patch
>>>
>>> @@
>>> struct pwm_device *p;
>>> expression e;
>>> @@
>>> (
>>> -(p)->polarity = e;
>>> +pwm_set_polarity((p), e);
>>> |
>>> -(p)->polarity
>>> +pwm_get_polarity((p))
>>> |
>>> -(p)->period = e;
>>> +pwm_set_period((p), e);
>>> |
>>> -(p)->period
>>> +pwm_get_period((p))
>>> |
>>> -(p)->duty_cycle = e;
>>> +pwm_set_duty_cycle((p), e);
>>> |
>>> -(p)->duty_cycle
>>> +pwm_get_duty_cycle((p))
>>> )
>>> --->8---
>>> ---
>>>   drivers/input/misc/max77693-haptic.c | 7 ++++---
>>>   1 file changed, 4 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/input/misc/max77693-haptic.c b/drivers/input/misc/max77693-haptic.c
>>> index 6d96bff..a038fb3 100644
>>> --- a/drivers/input/misc/max77693-haptic.c
>>> +++ b/drivers/input/misc/max77693-haptic.c
>>> @@ -70,10 +70,11 @@ struct max77693_haptic {
>>>
>>>   static int max77693_haptic_set_duty_cycle(struct max77693_haptic *haptic)
>>>   {
>>> -	int delta = (haptic->pwm_dev->period + haptic->pwm_duty) / 2;
>>> +	int delta = (pwm_get_period((haptic->pwm_dev)) + haptic->pwm_duty) / 2;
>>
>> Double parentheses over argument are not needed so just:
>> pwm_get_period(haptic->pwm_dev) + ...
>
> Actually it was generated with coccinelle, hence I didn't fix existing
> coding style issues, but I have no problem fixing them.
>
There was no existing coding style issue. Your coccinelle script introduces it.
You might want to consider updating your script and remove the unnecessary (( ))
from it.

Guenter

> Thanks,
>
> Boris
>
>>
>> Beside that patch looks good, so with removing parentheses here and below:
>>
>> Reviewed-by: Krzysztof Kozlowski <k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
>>
>> Best regards,
>> Krzysztof
>>
>>>   	int error;
>>>
>>> -	error = pwm_config(haptic->pwm_dev, delta, haptic->pwm_dev->period);
>>> +	error = pwm_config(haptic->pwm_dev, delta,
>>> +			   pwm_get_period((haptic->pwm_dev)));
>>>   	if (error) {
>>>   		dev_err(haptic->dev, "failed to configure pwm: %d\n", error);
>>>   		return error;
>>> @@ -245,7 +246,7 @@ static int max77693_haptic_play_effect(struct input_dev *dev, void *data,
>>>   	 * The formula to convert magnitude to pwm_duty as follows:
>>>   	 * - pwm_duty = (magnitude * pwm_period) / MAX_MAGNITUDE(0xFFFF)
>>>   	 */
>>> -	period_mag_multi = (u64)haptic->pwm_dev->period * haptic->magnitude;
>>> +	period_mag_multi = (u64)pwm_get_period((haptic->pwm_dev)) * haptic->magnitude;
>>>   	haptic->pwm_duty = (unsigned int)(period_mag_multi >>
>>>   						MAX_MAGNITUDE_SHIFT);
>>>
>>>
>>
>
>
>

Re: [PATCH v4 05/24] misc: max77693-haptic: use pwm_get_xxx() helpers where appropriate

[Boris Brezillon]

On Mon, 16 Nov 2015 07:55:33 -0800
Guenter Roeck <linux@roeck-us.net> wrote:

> On 11/16/2015 05:55 AM, Boris Brezillon wrote:
> > Hi Krzysztof,
> >
> > On Mon, 16 Nov 2015 22:10:40 +0900
> > Krzysztof Kozlowski <k.kozlowski@samsung.com> wrote:
> >
> >> W dniu 16.11.2015 o 17:56, Boris Brezillon pisze:
> >>> Use pwm_get_xxx() helpers instead of directly accessing the pwm->xxx field.
> >>> Doing that will ease adaptation of the PWM framework to support atomic
> >>> update.
> >>>
> >>> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> >>> ---
> >>> Patch generated with the following coccinelle script:
> >>>
> >>> --->8---
> >>> virtual patch
> >>>
> >>> @@
> >>> struct pwm_device *p;
> >>> expression e;
> >>> @@
> >>> (
> >>> -(p)->polarity = e;
> >>> +pwm_set_polarity((p), e);
> >>> |
> >>> -(p)->polarity
> >>> +pwm_get_polarity((p))
> >>> |
> >>> -(p)->period = e;
> >>> +pwm_set_period((p), e);
> >>> |
> >>> -(p)->period
> >>> +pwm_get_period((p))
> >>> |
> >>> -(p)->duty_cycle = e;
> >>> +pwm_set_duty_cycle((p), e);
> >>> |
> >>> -(p)->duty_cycle
> >>> +pwm_get_duty_cycle((p))
> >>> )
> >>> --->8---
> >>> ---
> >>>   drivers/input/misc/max77693-haptic.c | 7 ++++---
> >>>   1 file changed, 4 insertions(+), 3 deletions(-)
> >>>
> >>> diff --git a/drivers/input/misc/max77693-haptic.c b/drivers/input/misc/max77693-haptic.c
> >>> index 6d96bff..a038fb3 100644
> >>> --- a/drivers/input/misc/max77693-haptic.c
> >>> +++ b/drivers/input/misc/max77693-haptic.c
> >>> @@ -70,10 +70,11 @@ struct max77693_haptic {
> >>>
> >>>   static int max77693_haptic_set_duty_cycle(struct max77693_haptic *haptic)
> >>>   {
> >>> -	int delta = (haptic->pwm_dev->period + haptic->pwm_duty) / 2;
> >>> +	int delta = (pwm_get_period((haptic->pwm_dev)) + haptic->pwm_duty) / 2;
> >>
> >> Double parentheses over argument are not needed so just:
> >> pwm_get_period(haptic->pwm_dev) + ...
> >
> > Actually it was generated with coccinelle, hence I didn't fix existing
> > coding style issues, but I have no problem fixing them.
> >
> There was no existing coding style issue. Your coccinelle script introduces it.
> You might want to consider updating your script and remove the unnecessary (( ))
> from it.

My bad, you are right: my script is buggy. I'll fix that.

Thanks,

Boris


-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Re: [PATCH v4 05/24] misc: max77693-haptic: use pwm_get_xxx() helpers where appropriate

[Dmitry Torokhov]

On Mon, Nov 16, 2015 at 09:56:28AM +0100, Boris Brezillon wrote:
> Use pwm_get_xxx() helpers instead of directly accessing the pwm->xxx field.
> Doing that will ease adaptation of the PWM framework to support atomic
> update.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Could you please tag input-related bits with "Input: driver - ... "
instead of "misc: ... "?

Thanks!

-- 
Dmitry

[PATCH v4 06/24] pwm: introduce default period and polarity concepts

[Boris Brezillon]

When requested by a user, the PWM is assigned a default period and polarity
extracted from the DT, the platform data or statically set by the driver.
Those default values are currently stored in the period and polarity
fields of the pwm_device struct, but they will be stored somewhere else
once we have introduced the architecture allowing for hardware state
retrieval.

The pwm_set_default_polarity and pwm_set_default_period should only be
used by PWM drivers or the PWM core infrastructure to specify the
default period and polarity values.

PWM users might call the pwm_get_default_period to query the default
period value. There is currently no helper to query the default
polarity, but it might be added later on if there is a need for it.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Tested-by: Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
---
 include/linux/pwm.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index cfc3ed4..8ba57fc 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -118,11 +118,22 @@ static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
 		pwm->period = period;
 }
 
+static inline void pwm_set_default_period(struct pwm_device *pwm,
+					  unsigned int period)
+{
+	pwm_set_period(pwm, period);
+}
+
 static inline unsigned int pwm_get_period(const struct pwm_device *pwm)
 {
 	return pwm ? pwm->period : 0;
 }
 
+static inline unsigned int pwm_get_default_period(const struct pwm_device *pwm)
+{
+	return pwm_get_period(pwm);
+}
+
 static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)
 {
 	if (pwm)
@@ -139,6 +150,12 @@ static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm)
  */
 int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);
 
+static inline void pwm_set_default_polarity(struct pwm_device *pwm,
+					    enum pwm_polarity polarity)
+{
+	pwm_set_polarity(pwm, polarity);
+}
+
 static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
 {
 	return pwm ? pwm->polarity : PWM_POLARITY_NORMAL;
-- 
2.1.4

[PATCH v4 07/24] pwm: use pwm_get/set_default_xxx() helpers where appropriate

[Boris Brezillon]

pwm_set/get_default_xxx() helpers have been introduced to differentiate
the default PWM states (those retrieved through DT, PWM lookup table or
statically assigned by the driver) and the current PWM ones.
Make use of those helpers where appropriate.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Tested-by: Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
Reviewed-by: Alexandre Belloni <alexandre.belloni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Acked-by: Robert Jarzmik <robert.jarzmik-GANU6spQydw@public.gmane.org>
---
 drivers/pwm/core.c      | 14 +++++++-------
 drivers/pwm/pwm-pxa.c   |  2 +-
 drivers/pwm/pwm-sun4i.c |  3 ++-
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index d24ca5f..59073a1 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -146,12 +146,12 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
 	if (IS_ERR(pwm))
 		return pwm;
 
-	pwm_set_period(pwm, args->args[1]);
+	pwm_set_default_period(pwm, args->args[1]);
 
 	if (args->args[2] & PWM_POLARITY_INVERTED)
-		pwm_set_polarity(pwm, PWM_POLARITY_INVERSED);
+		pwm_set_default_polarity(pwm, PWM_POLARITY_INVERSED);
 	else
-		pwm_set_polarity(pwm, PWM_POLARITY_NORMAL);
+		pwm_set_default_polarity(pwm, PWM_POLARITY_NORMAL);
 
 	return pwm;
 }
@@ -172,7 +172,7 @@ of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
 	if (IS_ERR(pwm))
 		return pwm;
 
-	pwm_set_period(pwm, args->args[1]);
+	pwm_set_default_period(pwm, args->args[1]);
 
 	return pwm;
 }
@@ -268,7 +268,7 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
 		pwm->chip = chip;
 		pwm->pwm = chip->base + i;
 		pwm->hwpwm = i;
-		pwm->polarity = polarity;
+		pwm_set_default_polarity(pwm, polarity);
 		mutex_init(&pwm->lock);
 
 		radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
@@ -751,8 +751,8 @@ struct pwm_device *pwm_get(struct device *dev, const char *con_id)
 	if (IS_ERR(pwm))
 		goto out;
 
-	pwm_set_period(pwm, chosen->period);
-	pwm_set_polarity(pwm, chosen->polarity);
+	pwm_set_default_period(pwm, chosen->period);
+	pwm_set_default_polarity(pwm, chosen->polarity);
 
 out:
 	mutex_unlock(&pwm_lookup_lock);
diff --git a/drivers/pwm/pwm-pxa.c b/drivers/pwm/pwm-pxa.c
index cb2f702..65b80aa 100644
--- a/drivers/pwm/pwm-pxa.c
+++ b/drivers/pwm/pwm-pxa.c
@@ -160,7 +160,7 @@ pxa_pwm_of_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
 	if (IS_ERR(pwm))
 		return pwm;
 
-	pwm_set_period(pwm, args->args[0]);
+	pwm_set_default_period(pwm, args->args[0]);
 
 	return pwm;
 }
diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
index 67af9f6..f6a7451 100644
--- a/drivers/pwm/pwm-sun4i.c
+++ b/drivers/pwm/pwm-sun4i.c
@@ -354,7 +354,8 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
 	val = sun4i_pwm_readl(pwm, PWM_CTRL_REG);
 	for (i = 0; i < pwm->chip.npwm; i++)
 		if (!(val & BIT_CH(PWM_ACT_STATE, i)))
-			pwm->chip.pwms[i].polarity = PWM_POLARITY_INVERSED;
+			pwm_set_default_polarity(&pwm->chip.pwms[i],
+						 PWM_POLARITY_INVERSED);
 	clk_disable_unprepare(pwm->clk);
 
 	return 0;
-- 
2.1.4

[PATCH v4 08/24] leds: pwm: use pwm_get/set_default_xxx() helpers where appropriate

[Boris Brezillon]

pwm_set/get_default_xxx() helpers have been introduced to differentiate
the default PWM states (those retrieved through DT, PWM lookup table or
statically assigned by the driver) and the current ones.
Make use of those helpers where appropriate.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Acked-by: Jacek Anaszewski <j.anaszewski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
---
 drivers/leds/leds-pwm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
index 1d07e3e..2c564d1 100644
--- a/drivers/leds/leds-pwm.c
+++ b/drivers/leds/leds-pwm.c
@@ -125,7 +125,7 @@ static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
 	if (led_data->can_sleep)
 		INIT_WORK(&led_data->work, led_pwm_work);
 
-	led_data->period = pwm_get_period(led_data->pwm);
+	led_data->period = pwm_get_default_period(led_data->pwm);
 	if (!led_data->period && (led->pwm_period_ns > 0))
 		led_data->period = led->pwm_period_ns;
 
-- 
2.1.4

[PATCH v4 09/24] regulator: pwm: use pwm_get/set_default_xxx() helpers where appropriate

[Boris Brezillon]

pwm_set/get_default_xxx() helpers have been introduced to differentiate
the default PWM states (those retrieved through DT, PWM lookup table or
statically assigned by the driver) and the current ones.
Make use of those helpers where appropriate.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Tested-by: Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
---
 drivers/regulator/pwm-regulator.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
index 3aca067b..9ffdbd6 100644
--- a/drivers/regulator/pwm-regulator.c
+++ b/drivers/regulator/pwm-regulator.c
@@ -56,7 +56,7 @@ static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev,
 	int dutycycle;
 	int ret;
 
-	pwm_reg_period = pwm_get_period(drvdata->pwm);
+	pwm_reg_period = pwm_get_default_period(drvdata->pwm);
 
 	dutycycle = (pwm_reg_period *
 		    drvdata->duty_cycle_table[selector].dutycycle) / 100;
@@ -131,7 +131,7 @@ static int pwm_regulator_set_voltage(struct regulator_dev *rdev,
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
 	unsigned int ramp_delay = rdev->constraints->ramp_delay;
-	unsigned int period = pwm_get_period(drvdata->pwm);
+	unsigned int period = pwm_get_default_period(drvdata->pwm);
 	int duty_cycle;
 	int ret;
 
-- 
2.1.4

Re: [PATCH v4 09/24] regulator: pwm: use pwm_get/set_default_xxx() helpers where appropriate

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 634 bytes --]

On Mon, Nov 16, 2015 at 09:56:32AM +0100, Boris Brezillon wrote:

> +++ b/drivers/regulator/pwm-regulator.c
> @@ -56,7 +56,7 @@ static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev,
>  	int dutycycle;
>  	int ret;
>  
> -	pwm_reg_period = pwm_get_period(drvdata->pwm);
> +	pwm_reg_period = pwm_get_default_period(drvdata->pwm);
>  
>  	dutycycle = (pwm_reg_period *
>  		    drvdata->duty_cycle_table[selector].dutycycle) / 100;

It's not clear to me that we're not looking for the current period here
or in the other use.  Won't configuring based on a period other than the
one that has been set give the wrong answer?

Re: [PATCH v4 09/24] regulator: pwm: use pwm_get/set_default_xxx() helpers where appropriate

[Boris Brezillon]

Hi Mark,

On Mon, 16 Nov 2015 10:55:58 +0000
Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:

> On Mon, Nov 16, 2015 at 09:56:32AM +0100, Boris Brezillon wrote:
> 
> > +++ b/drivers/regulator/pwm-regulator.c
> > @@ -56,7 +56,7 @@ static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev,
> >  	int dutycycle;
> >  	int ret;
> >  
> > -	pwm_reg_period = pwm_get_period(drvdata->pwm);
> > +	pwm_reg_period = pwm_get_default_period(drvdata->pwm);
> >  
> >  	dutycycle = (pwm_reg_period *
> >  		    drvdata->duty_cycle_table[selector].dutycycle) / 100;
> 
> It's not clear to me that we're not looking for the current period here
> or in the other use.  Won't configuring based on a period other than the
> one that has been set give the wrong answer?

Hm, maybe that's naming problem. What I call the 'default' period here
is actually the period configured in your board file (using a PWM lookup
table) or your DT. This value represent the period requested by the PWM
user not a default value specified by the PWM chip driver.

The reason we're not using the 'current' period value is because it may
have been set by the bootloader, and may be inappropriate for our use
case (ie. the period may be to small to represent the different
voltages).
ITOH, we're using the current period value when calculating the current
voltage, because we want to get the correct voltage value, and the PWM
device may still use the configuration set by the bootloader (not the
default one specified in your board or DT files).

I hope this clarifies the differences between the current and default
period, and why we should use the default value here.

Best Regards,

Boris

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Re: [PATCH v4 09/24] regulator: pwm: use pwm_get/set_default_xxx() helpers where appropriate

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 1916 bytes --]

On Mon, Nov 16, 2015 at 01:23:59PM +0100, Boris Brezillon wrote:
> Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
> > On Mon, Nov 16, 2015 at 09:56:32AM +0100, Boris Brezillon wrote:

> > > -	pwm_reg_period = pwm_get_period(drvdata->pwm);
> > > +	pwm_reg_period = pwm_get_default_period(drvdata->pwm);

> > It's not clear to me that we're not looking for the current period here
> > or in the other use.  Won't configuring based on a period other than the
> > one that has been set give the wrong answer?

> Hm, maybe that's naming problem. What I call the 'default' period here
> is actually the period configured in your board file (using a PWM lookup
> table) or your DT. This value represent the period requested by the PWM
> user not a default value specified by the PWM chip driver.

> The reason we're not using the 'current' period value is because it may
> have been set by the bootloader, and may be inappropriate for our use
> case (ie. the period may be to small to represent the different
> voltages).

> ITOH, we're using the current period value when calculating the current
> voltage, because we want to get the correct voltage value, and the PWM
> device may still use the configuration set by the bootloader (not the
> default one specified in your board or DT files).

> I hope this clarifies the differences between the current and default
> period, and why we should use the default value here.

To be honest I'm still a bit confused here.  When do we actually apply
the default setting and why do we keep on having to constantly override
it rather than doing this once at boot?  It feels wrong to be using it
every time we set anything.  I'd expect it to be something we only need
to do at probe time or which would automatically be handled by the PWM
framework (but that'd have issues changing the state and potentially
breaking things if done in an uncoordiated fashion).

Re: [PATCH v4 09/24] regulator: pwm: use pwm_get/set_default_xxx() helpers where appropriate

[Boris Brezillon]

On Mon, 16 Nov 2015 18:42:38 +0000
Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:

> On Mon, Nov 16, 2015 at 01:23:59PM +0100, Boris Brezillon wrote:
> > Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
> > > On Mon, Nov 16, 2015 at 09:56:32AM +0100, Boris Brezillon wrote:
> 
> > > > -	pwm_reg_period = pwm_get_period(drvdata->pwm);
> > > > +	pwm_reg_period = pwm_get_default_period(drvdata->pwm);
> 
> > > It's not clear to me that we're not looking for the current period here
> > > or in the other use.  Won't configuring based on a period other than the
> > > one that has been set give the wrong answer?
> 
> > Hm, maybe that's naming problem. What I call the 'default' period here
> > is actually the period configured in your board file (using a PWM lookup
> > table) or your DT. This value represent the period requested by the PWM
> > user not a default value specified by the PWM chip driver.
> 
> > The reason we're not using the 'current' period value is because it may
> > have been set by the bootloader, and may be inappropriate for our use
> > case (ie. the period may be to small to represent the different
> > voltages).
> 
> > ITOH, we're using the current period value when calculating the current
> > voltage, because we want to get the correct voltage value, and the PWM
> > device may still use the configuration set by the bootloader (not the
> > default one specified in your board or DT files).
> 
> > I hope this clarifies the differences between the current and default
> > period, and why we should use the default value here.
> 
> To be honest I'm still a bit confused here.  When do we actually apply
> the default setting and why do we keep on having to constantly override
> it rather than doing this once at boot?

That's why I said the 'default' name may be inappropriate. The
default values are actually never directly applied by the PWM framework.
It's the default value for a specific PWM user, so it can be applied by
the PWM user when he wants. It's more here as a reference, nothing
forces the PWM user to use this specific value.

> It feels wrong to be using it
> every time we set anything.  I'd expect it to be something we only need
> to do at probe time or which would automatically be handled by the PWM
> framework (but that'd have issues changing the state and potentially
> breaking things if done in an uncoordiated fashion).

The whole point of this series is to smoothly take over the bootloader
config. This is why we are keeping the PWM untouched until someone
really wants to change the regulator output. We should be able to apply
the 'default' PWM period when probing the device, but this means first
extracting the current voltage from the PWM state and then applying a
new dutycycle and the default period in a single operation. Not sure
it's worth the trouble.

Doing it in the PWM framework is not really possible, because the PWM
lookup table and DT definitions are only defining the 'default' period
value not the 'default' dutycycle, and applying that automatically when
requesting the PWM means generating a glitch on the PWM signal
(dutycycle will be set to 0 until the user changes it using
pwm_config() or pwm_apply_state()) which is exactly what we're trying to
solve here.

Also, note that you have to pass the period anyway when configuring the
PWM, so passing the default one or the current one should be pretty
much the same in term of performances (unless the PWM driver is able
to optimize its setting if the period does not change).

Best Regards,

Boris

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Re: [PATCH v4 09/24] regulator: pwm: use pwm_get/set_default_xxx() helpers where appropriate

[Boris Brezillon]

Hi,

On Mon, 16 Nov 2015 18:42:38 +0000
Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:

> On Mon, Nov 16, 2015 at 01:23:59PM +0100, Boris Brezillon wrote:
> > Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
> > > On Mon, Nov 16, 2015 at 09:56:32AM +0100, Boris Brezillon wrote:
> 
> > > > -	pwm_reg_period = pwm_get_period(drvdata->pwm);
> > > > +	pwm_reg_period = pwm_get_default_period(drvdata->pwm);
> 
> > > It's not clear to me that we're not looking for the current period here
> > > or in the other use.  Won't configuring based on a period other than the
> > > one that has been set give the wrong answer?
> 
> > Hm, maybe that's naming problem. What I call the 'default' period here
> > is actually the period configured in your board file (using a PWM lookup
> > table) or your DT. This value represent the period requested by the PWM
> > user not a default value specified by the PWM chip driver.
> 
> > The reason we're not using the 'current' period value is because it may
> > have been set by the bootloader, and may be inappropriate for our use
> > case (ie. the period may be to small to represent the different
> > voltages).
> 
> > ITOH, we're using the current period value when calculating the current
> > voltage, because we want to get the correct voltage value, and the PWM
> > device may still use the configuration set by the bootloader (not the
> > default one specified in your board or DT files).
> 
> > I hope this clarifies the differences between the current and default
> > period, and why we should use the default value here.
> 
> To be honest I'm still a bit confused here.  When do we actually apply
> the default setting and why do we keep on having to constantly override
> it rather than doing this once at boot?  It feels wrong to be using it
> every time we set anything.  I'd expect it to be something we only need
> to do at probe time or which would automatically be handled by the PWM
> framework (but that'd have issues changing the state and potentially
> breaking things if done in an uncoordiated fashion).

Thierry, I didn't hear from you after the long discussion we had on IRC
a few weeks ago.
The conclusion of this discussion was that using
pwm_get_default_period() was not acceptable (even after renaming it
differently, like pwm_get_reference_period()), because it was
disturbing to get the default/reference period each time we wanted to
configure the PWM differently.
Another suggestion was to automatically reconfigure the PWM duty_ns
value based on the initial PWM state (retrieved through hardware
readout) and the default period value (specified in the PWM lookup table
or the DT). But this implied supporting hardware readout in all PWM
drivers, which prevents a smooth migration to this new approach.

I also proposed to provide helpers to hide the duty cycle to active
time calculation in the PWM core, so that PWM users just have to choose
their scale (percent, or any other custom scale) and set their duty
cycle based on this scale instead of specifying an active/on time in
nanosecond. You didn't seem to like this idea, but I gave it a try
(see here [1]), and think it might be worth looking at it.

The commit you should look at are [2], [3] and [4], and the idea is to
clarify the notion of duty-cycle, which, according to wikipedia [5]
(and a lot of other references) is supposed to be expressed in a
relative unit (percent, or any other scale as said earlier).
After renaming the pwm_set/get_duty_cycle() helpers into
pwm_set/get_active_time() we can define a new pwm_set_duty_cycle()
helper to let the PWM user configure its PWM device relatively to a
chosen scale, without asking him to choose the PWM period (the
conversion is done based on the default/reference period).
The pwm_get_duty_cycle() is doing the reverse conversion: it returns the
duty-cycle expressed relatively to the scale (here the current PWM
period is used to handle the case where the PWM user hasn't configure
the PWM yet, but want to retrieve the current duty-cycle extracted from
hardware readout).

Please let me know what you think of this approach, and if you're happy
with it I'll rework my series accordingly.

Best Regards,

Boris

[1]https://github.com/bbrezillon/linux-rk/commits/atomic-pwm-alt
[2]https://github.com/bbrezillon/linux-rk/commit/d7d4d04e147d4ec349c59f70e141877661930c6d
[3]https://github.com/bbrezillon/linux-rk/commit/66ce78f308f3eb1a9c536689352f208fd51c9030
[4]https://github.com/bbrezillon/linux-rk/commit/07882a2dd21f0d17d83640ff55204cc7a7d4c8f7
[5]https://en.wikipedia.org/wiki/Duty_cycle

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Re: [PATCH v4 09/24] regulator: pwm: use pwm_get/set_default_xxx() helpers where appropriate

[Boris Brezillon]

Hi Thierry,

I'm trying to get these "atomic PWM config" and "initial PWM state
retrieval" stuff in for at least 3 releases. I can understand that some
things have to be discussed and reworked in order to be good enough for
mainline, but that's not what I'm seeing here.

You and Mark raised some concerns about the usage of the
pwm_{get,set}_default_xxx() helpers which I tried to address by
proposing something else. I asked you to comment on it a few weeks ago,
but you never did.
You also told me that you would search for an alternative solution, but
never came back to me.

So I think it's now time to take a decision, whether you want to take
this series with some minor reworks (changing function names to clarify
what is a default and current PWM state), or decide that you expect
something else (but in that case I'd like you to explain what you want).

And by the way, the behavior you're complaining about is already
currently in place: even if the pwm_get_period() function does not
contain the 'default' word in its name, what's actually returned is the
default (or reference) period (the one retrieved from the DT or the PWM
lookup table) not the period currently in use on the PWM device (the
same goes for other helpers).

Can we please settle on something for 4.6 so that I can repost a series
when 4.5-rc1 is out?

Thanks,

Boris

On Wed, 2 Dec 2015 11:37:20 +0100
Boris Brezillon <boris.brezillon@free-electrons.com> wrote:

> Hi,
> 
> On Mon, 16 Nov 2015 18:42:38 +0000
> Mark Brown <broonie@kernel.org> wrote:
> 
> > On Mon, Nov 16, 2015 at 01:23:59PM +0100, Boris Brezillon wrote:
> > > Mark Brown <broonie@kernel.org> wrote:
> > > > On Mon, Nov 16, 2015 at 09:56:32AM +0100, Boris Brezillon wrote:
> > 
> > > > > -	pwm_reg_period = pwm_get_period(drvdata->pwm);
> > > > > +	pwm_reg_period = pwm_get_default_period(drvdata->pwm);
> > 
> > > > It's not clear to me that we're not looking for the current period here
> > > > or in the other use.  Won't configuring based on a period other than the
> > > > one that has been set give the wrong answer?
> > 
> > > Hm, maybe that's naming problem. What I call the 'default' period here
> > > is actually the period configured in your board file (using a PWM lookup
> > > table) or your DT. This value represent the period requested by the PWM
> > > user not a default value specified by the PWM chip driver.
> > 
> > > The reason we're not using the 'current' period value is because it may
> > > have been set by the bootloader, and may be inappropriate for our use
> > > case (ie. the period may be to small to represent the different
> > > voltages).
> > 
> > > ITOH, we're using the current period value when calculating the current
> > > voltage, because we want to get the correct voltage value, and the PWM
> > > device may still use the configuration set by the bootloader (not the
> > > default one specified in your board or DT files).
> > 
> > > I hope this clarifies the differences between the current and default
> > > period, and why we should use the default value here.
> > 
> > To be honest I'm still a bit confused here.  When do we actually apply
> > the default setting and why do we keep on having to constantly override
> > it rather than doing this once at boot?  It feels wrong to be using it
> > every time we set anything.  I'd expect it to be something we only need
> > to do at probe time or which would automatically be handled by the PWM
> > framework (but that'd have issues changing the state and potentially
> > breaking things if done in an uncoordiated fashion).
> 
> Thierry, I didn't hear from you after the long discussion we had on IRC
> a few weeks ago.
> The conclusion of this discussion was that using
> pwm_get_default_period() was not acceptable (even after renaming it
> differently, like pwm_get_reference_period()), because it was
> disturbing to get the default/reference period each time we wanted to
> configure the PWM differently.
> Another suggestion was to automatically reconfigure the PWM duty_ns
> value based on the initial PWM state (retrieved through hardware
> readout) and the default period value (specified in the PWM lookup table
> or the DT). But this implied supporting hardware readout in all PWM
> drivers, which prevents a smooth migration to this new approach.
> 
> I also proposed to provide helpers to hide the duty cycle to active
> time calculation in the PWM core, so that PWM users just have to choose
> their scale (percent, or any other custom scale) and set their duty
> cycle based on this scale instead of specifying an active/on time in
> nanosecond. You didn't seem to like this idea, but I gave it a try
> (see here [1]), and think it might be worth looking at it.
> 
> The commit you should look at are [2], [3] and [4], and the idea is to
> clarify the notion of duty-cycle, which, according to wikipedia [5]
> (and a lot of other references) is supposed to be expressed in a
> relative unit (percent, or any other scale as said earlier).
> After renaming the pwm_set/get_duty_cycle() helpers into
> pwm_set/get_active_time() we can define a new pwm_set_duty_cycle()
> helper to let the PWM user configure its PWM device relatively to a
> chosen scale, without asking him to choose the PWM period (the
> conversion is done based on the default/reference period).
> The pwm_get_duty_cycle() is doing the reverse conversion: it returns the
> duty-cycle expressed relatively to the scale (here the current PWM
> period is used to handle the case where the PWM user hasn't configure
> the PWM yet, but want to retrieve the current duty-cycle extracted from
> hardware readout).
> 
> Please let me know what you think of this approach, and if you're happy
> with it I'll rework my series accordingly.
> 
> Best Regards,
> 
> Boris
> 
> [1]https://github.com/bbrezillon/linux-rk/commits/atomic-pwm-alt
> [2]https://github.com/bbrezillon/linux-rk/commit/d7d4d04e147d4ec349c59f70e141877661930c6d
> [3]https://github.com/bbrezillon/linux-rk/commit/66ce78f308f3eb1a9c536689352f208fd51c9030
> [4]https://github.com/bbrezillon/linux-rk/commit/07882a2dd21f0d17d83640ff55204cc7a7d4c8f7
> [5]https://en.wikipedia.org/wiki/Duty_cycle
> 



-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[PATCH v4 10/24] backlight: pwm: use pwm_get/set_default_xxx() helpers where appropriate

[Boris Brezillon]

pwm_set/get_default_xxx() helpers have been introduced to differentiate
the default PWM states (those retrieved through DT, PWM lookup table or
statically assigned by the driver) and the current ones.
Make use of those helpers where appropriate.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Acked-by: Lee Jones <lee.jones-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
 drivers/video/backlight/lm3630a_bl.c | 4 ++--
 drivers/video/backlight/pwm_bl.c     | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/video/backlight/lm3630a_bl.c b/drivers/video/backlight/lm3630a_bl.c
index 35fe482..449ebc3 100644
--- a/drivers/video/backlight/lm3630a_bl.c
+++ b/drivers/video/backlight/lm3630a_bl.c
@@ -162,7 +162,7 @@ static int lm3630a_intr_config(struct lm3630a_chip *pchip)
 
 static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
 {
-	unsigned int period = pwm_get_period(pchip->pwmd);
+	unsigned int period = pwm_get_default_period(pchip->pwmd);
 	unsigned int duty = br * period / br_max;
 
 	pwm_config(pchip->pwmd, duty, period);
@@ -425,7 +425,7 @@ static int lm3630a_probe(struct i2c_client *client,
 			return PTR_ERR(pchip->pwmd);
 		}
 	}
-	pchip->pwmd->period = pdata->pwm_period;
+	pwm_set_default_period(pchip->pwmd, pdata->pwm_period);
 
 	/* interrupt enable  : irq 0 is not allowed */
 	pchip->irq = client->irq;
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index ae3c6b6..54d5a03 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -293,7 +293,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	 * set the period from platform data if it has not already been set
 	 * via the PWM lookup table.
 	 */
-	pb->period = pwm_get_period(pb->pwm);
+	pb->period = pwm_get_default_period(pb->pwm);
 	if (!pb->period && (data->pwm_period_ns > 0)) {
 		pb->period = data->pwm_period_ns;
 		pwm_set_period(pb->pwm, data->pwm_period_ns);
-- 
2.1.4

[PATCH v4 11/24] fbdev: use pwm_get/set_default_xxx() helpers where appropriate

[Boris Brezillon]

pwm_set/get_default_xxx() helpers have been introduced to differentiate
the default PWM states (those retrieved through DT, PWM lookup table or
statically assigned by the driver) and the current ones.
Make use of those helpers where appropriate.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 drivers/video/fbdev/ssd1307fb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index fa34808..81f4885 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -294,7 +294,7 @@ static int ssd1307fb_init(struct ssd1307fb_par *par)
 			return PTR_ERR(par->pwm);
 		}
 
-		par->pwm_period = pwm_get_period(par->pwm);
+		par->pwm_period = pwm_get_default_period(par->pwm);
 		/* Enable the PWM */
 		pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period);
 		pwm_enable(par->pwm);
-- 
2.1.4

[PATCH v4 12/24] misc: max77693: use pwm_get/set_default_xxx() helpers where appropriate

[Boris Brezillon]

pwm_set/get_default_xxx() helpers have been introduced to differentiate
the default PWM states (those retrieved through DT, PWM lookup table or
statically assigned by the driver) and the current ones.
Make use of those helpers where appropriate.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 drivers/input/misc/max77693-haptic.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/input/misc/max77693-haptic.c b/drivers/input/misc/max77693-haptic.c
index a038fb3..89f5055 100644
--- a/drivers/input/misc/max77693-haptic.c
+++ b/drivers/input/misc/max77693-haptic.c
@@ -70,11 +70,12 @@ struct max77693_haptic {
 
 static int max77693_haptic_set_duty_cycle(struct max77693_haptic *haptic)
 {
-	int delta = (pwm_get_period((haptic->pwm_dev)) + haptic->pwm_duty) / 2;
+	int delta = (pwm_get_default_period((haptic->pwm_dev)) +
+		     haptic->pwm_duty) / 2;
 	int error;
 
 	error = pwm_config(haptic->pwm_dev, delta,
-			   pwm_get_period((haptic->pwm_dev)));
+			   pwm_get_default_period((haptic->pwm_dev)));
 	if (error) {
 		dev_err(haptic->dev, "failed to configure pwm: %d\n", error);
 		return error;
@@ -246,7 +247,8 @@ static int max77693_haptic_play_effect(struct input_dev *dev, void *data,
 	 * The formula to convert magnitude to pwm_duty as follows:
 	 * - pwm_duty = (magnitude * pwm_period) / MAX_MAGNITUDE(0xFFFF)
 	 */
-	period_mag_multi = (u64)pwm_get_period((haptic->pwm_dev)) * haptic->magnitude;
+	period_mag_multi = (u64)pwm_get_default_period((haptic->pwm_dev)) *
+			   haptic->magnitude;
 	haptic->pwm_duty = (unsigned int)(period_mag_multi >>
 						MAX_MAGNITUDE_SHIFT);
 
-- 
2.1.4

[PATCH v4 13/24] hwmon: pwm-fan: use pwm_get/set_default_xxx() helpers where appropriate

[Boris Brezillon]

pwm_set/get_default_xxx() helpers have been introduced to differentiate
the default PWM states (those retrieved through DT, PWM lookup table or
statically assigned by the driver) and the current ones.
Make use of those helpers where appropriate.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 drivers/hwmon/pwm-fan.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 105b964..989d7b4 100644
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -47,8 +47,9 @@ static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
 	if (ctx->pwm_value == pwm)
 		goto exit_set_pwm_err;
 
-	duty = DIV_ROUND_UP(pwm * (pwm_get_period((ctx->pwm)) - 1), MAX_PWM);
-	ret = pwm_config(ctx->pwm, duty, pwm_get_period((ctx->pwm)));
+	duty = DIV_ROUND_UP(pwm * (pwm_get_default_period((ctx->pwm)) - 1),
+			    MAX_PWM);
+	ret = pwm_config(ctx->pwm, duty, pwm_get_default_period((ctx->pwm)));
 	if (ret)
 		goto exit_set_pwm_err;
 
@@ -234,10 +235,11 @@ static int pwm_fan_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, ctx);
 
 	/* Set duty cycle to maximum allowed */
-	duty_cycle = pwm_get_period((ctx->pwm)) - 1;
+	duty_cycle = pwm_get_default_period((ctx->pwm)) - 1;
 	ctx->pwm_value = MAX_PWM;
 
-	ret = pwm_config(ctx->pwm, duty_cycle, pwm_get_period((ctx->pwm)));
+	ret = pwm_config(ctx->pwm, duty_cycle,
+			 pwm_get_default_period((ctx->pwm)));
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to configure PWM\n");
 		return ret;
@@ -309,9 +311,10 @@ static int pwm_fan_resume(struct device *dev)
 	if (ctx->pwm_value == 0)
 		return 0;
 
-	duty = DIV_ROUND_UP(ctx->pwm_value * (pwm_get_period((ctx->pwm)) - 1),
+	duty = DIV_ROUND_UP(ctx->pwm_value *
+			    (pwm_get_default_period((ctx->pwm)) - 1),
 			    MAX_PWM);
-	ret = pwm_config(ctx->pwm, duty, pwm_get_period((ctx->pwm)));
+	ret = pwm_config(ctx->pwm, duty, pwm_get_default_period((ctx->pwm)));
 	if (ret)
 		return ret;
 	return pwm_enable(ctx->pwm);
-- 
2.1.4

Re: [PATCH v4 13/24] hwmon: pwm-fan: use pwm_get/set_default_xxx() helpers where appropriate

[Guenter Roeck]

On 11/16/2015 12:56 AM, Boris Brezillon wrote:
> pwm_set/get_default_xxx() helpers have been introduced to differentiate
> the default PWM states (those retrieved through DT, PWM lookup table or
> statically assigned by the driver) and the current ones.
> Make use of those helpers where appropriate.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> ---
>   drivers/hwmon/pwm-fan.c | 15 +++++++++------
>   1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
> index 105b964..989d7b4 100644
> --- a/drivers/hwmon/pwm-fan.c
> +++ b/drivers/hwmon/pwm-fan.c
> @@ -47,8 +47,9 @@ static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
>   	if (ctx->pwm_value == pwm)
>   		goto exit_set_pwm_err;
>
> -	duty = DIV_ROUND_UP(pwm * (pwm_get_period((ctx->pwm)) - 1), MAX_PWM);
> -	ret = pwm_config(ctx->pwm, duty, pwm_get_period((ctx->pwm)));
> +	duty = DIV_ROUND_UP(pwm * (pwm_get_default_period((ctx->pwm)) - 1),
> +			    MAX_PWM);
> +	ret = pwm_config(ctx->pwm, duty, pwm_get_default_period((ctx->pwm)));

Same here - please no unnecessary ( ) [ which were first introduced by
the other patch ].

Guenter

>   	if (ret)
>   		goto exit_set_pwm_err;
>
> @@ -234,10 +235,11 @@ static int pwm_fan_probe(struct platform_device *pdev)
>   	platform_set_drvdata(pdev, ctx);
>
>   	/* Set duty cycle to maximum allowed */
> -	duty_cycle = pwm_get_period((ctx->pwm)) - 1;
> +	duty_cycle = pwm_get_default_period((ctx->pwm)) - 1;
>   	ctx->pwm_value = MAX_PWM;
>
> -	ret = pwm_config(ctx->pwm, duty_cycle, pwm_get_period((ctx->pwm)));
> +	ret = pwm_config(ctx->pwm, duty_cycle,
> +			 pwm_get_default_period((ctx->pwm)));
>   	if (ret) {
>   		dev_err(&pdev->dev, "Failed to configure PWM\n");
>   		return ret;
> @@ -309,9 +311,10 @@ static int pwm_fan_resume(struct device *dev)
>   	if (ctx->pwm_value == 0)
>   		return 0;
>
> -	duty = DIV_ROUND_UP(ctx->pwm_value * (pwm_get_period((ctx->pwm)) - 1),
> +	duty = DIV_ROUND_UP(ctx->pwm_value *
> +			    (pwm_get_default_period((ctx->pwm)) - 1),
>   			    MAX_PWM);
> -	ret = pwm_config(ctx->pwm, duty, pwm_get_period((ctx->pwm)));
> +	ret = pwm_config(ctx->pwm, duty, pwm_get_default_period((ctx->pwm)));
>   	if (ret)
>   		return ret;
>   	return pwm_enable(ctx->pwm);
>

[PATCH v4 14/24] clk: pwm: use pwm_get/set_default_xxx() helpers where appropriate

[Boris Brezillon]

pwm_set/get_default_xxx() helpers have been introduced to differentiate
the default PWM states (those retrieved through DT, PWM lookup table or
statically assigned by the driver) and the current ones.
Make use of those helpers where appropriate.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 drivers/clk/clk-pwm.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/clk-pwm.c b/drivers/clk/clk-pwm.c
index b6306a2..642a49a 100644
--- a/drivers/clk/clk-pwm.c
+++ b/drivers/clk/clk-pwm.c
@@ -71,23 +71,23 @@ static int clk_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(pwm))
 		return PTR_ERR(pwm);
 
-	if (!pwm_get_period((pwm))) {
+	if (!pwm_get_default_period((pwm))) {
 		dev_err(&pdev->dev, "invalid PWM period\n");
 		return -EINVAL;
 	}
 
 	if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate))
-		clk_pwm->fixed_rate = NSEC_PER_SEC / pwm_get_period((pwm));
+		clk_pwm->fixed_rate = NSEC_PER_SEC / pwm_get_default_period((pwm));
 
-	if (pwm_get_period((pwm)) != NSEC_PER_SEC / clk_pwm->fixed_rate &&
-	    pwm_get_period((pwm)) != DIV_ROUND_UP(NSEC_PER_SEC, clk_pwm->fixed_rate)) {
+	if (pwm_get_default_period((pwm)) != NSEC_PER_SEC / clk_pwm->fixed_rate &&
+	    pwm_get_default_period((pwm)) != DIV_ROUND_UP(NSEC_PER_SEC, clk_pwm->fixed_rate)) {
 		dev_err(&pdev->dev,
 			"clock-frequency does not match PWM period\n");
 		return -EINVAL;
 	}
 
-	ret = pwm_config(pwm, (pwm_get_period((pwm)) + 1) >> 1,
-			 pwm_get_period((pwm)));
+	ret = pwm_config(pwm, (pwm_get_default_period((pwm)) + 1) >> 1,
+			 pwm_get_default_period((pwm)));
 	if (ret < 0)
 		return ret;
 
-- 
2.1.4

Re: [PATCH v4 14/24] clk: pwm: use pwm_get/set_default_xxx() helpers where appropriate

[Michael Turquette]

Hi Boris,

Quoting Boris Brezillon (2015-11-16 00:56:37)
> pwm_set/get_default_xxx() helpers have been introduced to differentiate
> the default PWM states (those retrieved through DT, PWM lookup table or
> statically assigned by the driver) and the current ones.
> Make use of those helpers where appropriate.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
> ---
>  drivers/clk/clk-pwm.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/clk/clk-pwm.c b/drivers/clk/clk-pwm.c
> index b6306a2..642a49a 100644
> --- a/drivers/clk/clk-pwm.c
> +++ b/drivers/clk/clk-pwm.c
> @@ -71,23 +71,23 @@ static int clk_pwm_probe(struct platform_device *pdev)
>         if (IS_ERR(pwm))
>                 return PTR_ERR(pwm);
>  
> -       if (!pwm_get_period((pwm))) {
> +       if (!pwm_get_default_period((pwm))) {

The change itself looks fine, but the semantic patch added extra parens.
Can you remove them? After doing so feel free to add:

Acked-by: Michael Turquette <mturquette-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>

[PATCH v4 15/24] pwm: define a new pwm_state struct

[Boris Brezillon]

The PWM state, represented by its period, duty_cycle and polarity,
is currently directly stored in the PWM device.
Declare a pwm_state structure embedding those field so that we can later
use this struct to atomically update all the PWM parameters at once.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 drivers/pwm/core.c  |  6 +++---
 include/linux/pwm.h | 30 +++++++++++++++++++-----------
 2 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 59073a1..f1c6769 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -447,8 +447,8 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
 	if (err)
 		return err;
 
-	pwm->duty_cycle = duty_ns;
-	pwm->period = period_ns;
+	pwm->state.duty_cycle = duty_ns;
+	pwm->state.period = period_ns;
 
 	return 0;
 }
@@ -485,7 +485,7 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
 	if (err)
 		goto unlock;
 
-	pwm->polarity = polarity;
+	pwm->state.polarity = polarity;
 
 unlock:
 	mutex_unlock(&pwm->lock);
diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index 8ba57fc..af42299 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -80,6 +80,18 @@ enum {
 	PWMF_EXPORTED = 1 << 2,
 };
 
+/*
+ * struct pwm_state - state of a PWM channel
+ * @period: PWM period (in nanoseconds)
+ * @duty_cycle: PWM duty cycle (in nanoseconds)
+ * @polarity: PWM polarity
+ */
+struct pwm_state {
+	unsigned int period;
+	unsigned int duty_cycle;
+	enum pwm_polarity polarity;
+};
+
 /**
  * struct pwm_device - PWM channel object
  * @label: name of the PWM device
@@ -89,9 +101,7 @@ enum {
  * @chip: PWM chip providing this PWM device
  * @chip_data: chip-private data associated with the PWM device
  * @lock: used to serialize accesses to the PWM device where necessary
- * @period: period of the PWM signal (in nanoseconds)
- * @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
- * @polarity: polarity of the PWM signal
+ * @state: curent PWM channel state
  */
 struct pwm_device {
 	const char *label;
@@ -102,9 +112,7 @@ struct pwm_device {
 	void *chip_data;
 	struct mutex lock;
 
-	unsigned int period;
-	unsigned int duty_cycle;
-	enum pwm_polarity polarity;
+	struct pwm_state state;
 };
 
 static inline bool pwm_is_enabled(const struct pwm_device *pwm)
@@ -115,7 +123,7 @@ static inline bool pwm_is_enabled(const struct pwm_device *pwm)
 static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
 {
 	if (pwm)
-		pwm->period = period;
+		pwm->state.period = period;
 }
 
 static inline void pwm_set_default_period(struct pwm_device *pwm,
@@ -126,7 +134,7 @@ static inline void pwm_set_default_period(struct pwm_device *pwm,
 
 static inline unsigned int pwm_get_period(const struct pwm_device *pwm)
 {
-	return pwm ? pwm->period : 0;
+	return pwm ? pwm->state.period : 0;
 }
 
 static inline unsigned int pwm_get_default_period(const struct pwm_device *pwm)
@@ -137,12 +145,12 @@ static inline unsigned int pwm_get_default_period(const struct pwm_device *pwm)
 static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)
 {
 	if (pwm)
-		pwm->duty_cycle = duty;
+		pwm->state.duty_cycle = duty;
 }
 
 static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm)
 {
-	return pwm ? pwm->duty_cycle : 0;
+	return pwm ? pwm->state.duty_cycle : 0;
 }
 
 /*
@@ -158,7 +166,7 @@ static inline void pwm_set_default_polarity(struct pwm_device *pwm,
 
 static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
 {
-	return pwm ? pwm->polarity : PWM_POLARITY_NORMAL;
+	return pwm ? pwm->state.polarity : PWM_POLARITY_NORMAL;
 }
 
 /**
-- 
2.1.4

[PATCH v4 16/24] pwm: move the enabled/disabled info to pwm_state struct

[Boris Brezillon]

Prepare the transition to PWM atomic update by moving the enabled/disabled
state into the pwm_state struct. This way we can easily update the whole
PWM state by copying the new state in the ->state field.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Tested-by: Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
---
 drivers/pwm/core.c  | 17 +++++++++++++----
 include/linux/pwm.h |  7 ++++---
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index f1c6769..6bbda6c 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -508,10 +508,10 @@ int pwm_enable(struct pwm_device *pwm)
 
 	mutex_lock(&pwm->lock);
 
-	if (!test_and_set_bit(PWMF_ENABLED, &pwm->flags)) {
+	if (!pwm_is_enabled(pwm)) {
 		err = pwm->chip->ops->enable(pwm->chip, pwm);
-		if (err)
-			clear_bit(PWMF_ENABLED, &pwm->flags);
+		if (!err)
+			pwm->state.enabled = true;
 	}
 
 	mutex_unlock(&pwm->lock);
@@ -526,8 +526,17 @@ EXPORT_SYMBOL_GPL(pwm_enable);
  */
 void pwm_disable(struct pwm_device *pwm)
 {
-	if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
+	if (!pwm)
+		return;
+
+	mutex_lock(&pwm->lock);
+
+	if (pwm_is_enabled(pwm)) {
 		pwm->chip->ops->disable(pwm->chip, pwm);
+		pwm->state.enabled = false;
+	}
+
+	mutex_unlock(&pwm->lock);
 }
 EXPORT_SYMBOL_GPL(pwm_disable);
 
diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index af42299..398c58c 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -76,8 +76,7 @@ enum pwm_polarity {
 
 enum {
 	PWMF_REQUESTED = 1 << 0,
-	PWMF_ENABLED = 1 << 1,
-	PWMF_EXPORTED = 1 << 2,
+	PWMF_EXPORTED = 1 << 1,
 };
 
 /*
@@ -85,11 +84,13 @@ enum {
  * @period: PWM period (in nanoseconds)
  * @duty_cycle: PWM duty cycle (in nanoseconds)
  * @polarity: PWM polarity
+ * @enabled: PWM enabled status
  */
 struct pwm_state {
 	unsigned int period;
 	unsigned int duty_cycle;
 	enum pwm_polarity polarity;
+	bool enabled;
 };
 
 /**
@@ -117,7 +118,7 @@ struct pwm_device {
 
 static inline bool pwm_is_enabled(const struct pwm_device *pwm)
 {
-	return test_bit(PWMF_ENABLED, &pwm->flags);
+	return pwm->state.enabled;
 }
 
 static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
-- 
2.1.4

[PATCH v4 17/24] backlight: pwm_bl: remove useless call to pwm_set_period

[Boris Brezillon]

The PWM period will be set when calling pwm_config. Remove this useless
call to pwm_set_period, which might mess up with the initial PWM state
once we have added proper support for PWM init state retrieval.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Acked-by: Lee Jones <lee.jones-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
 drivers/video/backlight/pwm_bl.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 54d5a03..5ff2976 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -292,12 +292,14 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	 * period, parsed from the DT, in the PWM device. For the non-DT case,
 	 * set the period from platform data if it has not already been set
 	 * via the PWM lookup table.
+	 * FIXME: This assignment should be dropped as soon as all the boards
+	 * have moved to the PWM lookup table approach. The same goes for the
+	 * pb->period field which should be replaced by
+	 * pwm_get_default_period() calls.
 	 */
 	pb->period = pwm_get_default_period(pb->pwm);
-	if (!pb->period && (data->pwm_period_ns > 0)) {
+	if (!pb->period && (data->pwm_period_ns > 0))
 		pb->period = data->pwm_period_ns;
-		pwm_set_period(pb->pwm, data->pwm_period_ns);
-	}
 
 	pb->lth_brightness = data->lth_brightness * (pb->period / pb->scale);
 
-- 
2.1.4

[PATCH v4 18/24] pwm: declare a default PWM state

[Boris Brezillon]

Prepare the addition of the PWM initial state retrieval by adding a default
state where all the parameters retrieved from DT, platform data or
statically forced by the hardware will be stored.
Once done we will be able to store the initial state in the ->state field
without risking to loose the default parameters.

Update the pwm_set/get_default_xxx helpers accordingly.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Tested-by: Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
---
 include/linux/pwm.h | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index 398c58c..292e7da 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -103,6 +103,7 @@ struct pwm_state {
  * @chip_data: chip-private data associated with the PWM device
  * @lock: used to serialize accesses to the PWM device where necessary
  * @state: curent PWM channel state
+ * @default_state: default PWM channel state
  */
 struct pwm_device {
 	const char *label;
@@ -114,6 +115,7 @@ struct pwm_device {
 	struct mutex lock;
 
 	struct pwm_state state;
+	struct pwm_state default_state;
 };
 
 static inline bool pwm_is_enabled(const struct pwm_device *pwm)
@@ -130,7 +132,8 @@ static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
 static inline void pwm_set_default_period(struct pwm_device *pwm,
 					  unsigned int period)
 {
-	pwm_set_period(pwm, period);
+	if (pwm)
+		pwm->default_state.period = period;
 }
 
 static inline unsigned int pwm_get_period(const struct pwm_device *pwm)
@@ -140,7 +143,7 @@ static inline unsigned int pwm_get_period(const struct pwm_device *pwm)
 
 static inline unsigned int pwm_get_default_period(const struct pwm_device *pwm)
 {
-	return pwm_get_period(pwm);
+	return pwm ? pwm->default_state.period : 0;
 }
 
 static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)
@@ -162,7 +165,8 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);
 static inline void pwm_set_default_polarity(struct pwm_device *pwm,
 					    enum pwm_polarity polarity)
 {
-	pwm_set_polarity(pwm, polarity);
+	if (pwm)
+		pwm->default_state.polarity = polarity;
 }
 
 static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
-- 
2.1.4

[PATCH v4 19/24] pwm: add the PWM initial state retrieval infra

[Boris Brezillon]

Add a ->reset_state() function to the pwm_ops struct to let PWM drivers
initialize the PWM state attached to a PWM device.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Tested-by: Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
---
 drivers/pwm/core.c  | 3 +++
 include/linux/pwm.h | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 6bbda6c..ce8b373 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -271,6 +271,9 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
 		pwm_set_default_polarity(pwm, polarity);
 		mutex_init(&pwm->lock);
 
+		if (chip->ops->reset_state)
+			chip->ops->reset_state(chip, pwm);
+
 		radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
 	}
 
diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index 292e7da..caa0ffe 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -182,6 +182,9 @@ static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
  * @set_polarity: configure the polarity of this PWM
  * @enable: enable PWM output toggling
  * @disable: disable PWM output toggling
+ * @reset_state: reset the current PWM state (pwm->state) to the actual
+ *		 hardware state. This function is only called once per
+ *		 PWM device when the PWM chip is registered.
  * @dbg_show: optional routine to show contents in debugfs
  * @owner: helps prevent removal of modules exporting active PWMs
  */
@@ -194,6 +197,7 @@ struct pwm_ops {
 			    enum pwm_polarity polarity);
 	int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm);
 	void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm);
+	void (*reset_state)(struct pwm_chip *chip, struct pwm_device *pwm);
 #ifdef CONFIG_DEBUG_FS
 	void (*dbg_show)(struct pwm_chip *chip, struct seq_file *s);
 #endif
-- 
2.1.4

[PATCH v4 22/24] pwm: rockchip: add initial state retrieval

[Boris Brezillon]

Implement the ->reset_state() function to expose initial state.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Tested-by: Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
---
 drivers/pwm/pwm-rockchip.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)

diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
index 7d9cc90..6eab25c 100644
--- a/drivers/pwm/pwm-rockchip.c
+++ b/drivers/pwm/pwm-rockchip.c
@@ -51,6 +51,7 @@ struct rockchip_pwm_data {
 
 	void (*set_enable)(struct pwm_chip *chip,
 			   struct pwm_device *pwm, bool enable);
+	void (*reset_state)(struct pwm_chip *chip, struct pwm_device *pwm);
 };
 
 static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
@@ -75,6 +76,18 @@ static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip,
 	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
 }
 
+static void rockchip_pwm_reset_state_v1(struct pwm_chip *chip,
+					struct pwm_device *pwm)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
+	u32 val;
+
+	val = readl(pc->base + pc->data->regs.ctrl);
+	if ((val & enable_conf) == enable_conf)
+		pwm->state.enabled = true;
+}
+
 static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
 				       struct pwm_device *pwm, bool enable)
 {
@@ -98,6 +111,54 @@ static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
 	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
 }
 
+static void rockchip_pwm_reset_state_v2(struct pwm_chip *chip,
+					struct pwm_device *pwm)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
+			  PWM_CONTINUOUS;
+	u32 val;
+
+	val = readl(pc->base + pc->data->regs.ctrl);
+	if ((val & enable_conf) != enable_conf)
+		return;
+
+	pwm->state.enabled = true;
+
+	if (!(val & PWM_DUTY_POSITIVE))
+		pwm->state.polarity = PWM_POLARITY_INVERSED;
+}
+
+static void rockchip_pwm_reset_state(struct pwm_chip *chip,
+				     struct pwm_device *pwm)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	unsigned long clk_rate;
+	u64 tmp;
+	int ret;
+
+	ret = clk_enable(pc->clk);
+	if (ret)
+		return;
+
+	clk_rate = clk_get_rate(pc->clk);
+
+	tmp = readl(pc->base + pc->data->regs.period);
+	tmp *= pc->data->prescaler * NSEC_PER_SEC;
+	do_div(tmp, clk_rate);
+	pwm->state.period = tmp;
+
+	tmp = readl(pc->base + pc->data->regs.duty);
+	tmp *= pc->data->prescaler * NSEC_PER_SEC;
+	do_div(tmp, clk_rate);
+	pwm->state.duty_cycle = tmp;
+
+	pc->data->reset_state(chip, chip->pwms);
+
+	if (!pwm_is_enabled(pwm))
+		clk_disable(pc->clk);
+}
+
 static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			       int duty_ns, int period_ns)
 {
@@ -171,6 +232,7 @@ static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 }
 
 static const struct pwm_ops rockchip_pwm_ops_v1 = {
+	.reset_state = rockchip_pwm_reset_state,
 	.config = rockchip_pwm_config,
 	.enable = rockchip_pwm_enable,
 	.disable = rockchip_pwm_disable,
@@ -178,6 +240,7 @@ static const struct pwm_ops rockchip_pwm_ops_v1 = {
 };
 
 static const struct pwm_ops rockchip_pwm_ops_v2 = {
+	.reset_state = rockchip_pwm_reset_state,
 	.config = rockchip_pwm_config,
 	.set_polarity = rockchip_pwm_set_polarity,
 	.enable = rockchip_pwm_enable,
@@ -195,6 +258,7 @@ static const struct rockchip_pwm_data pwm_data_v1 = {
 	.prescaler = 2,
 	.ops = &rockchip_pwm_ops_v1,
 	.set_enable = rockchip_pwm_set_enable_v1,
+	.reset_state = rockchip_pwm_reset_state_v1,
 };
 
 static const struct rockchip_pwm_data pwm_data_v2 = {
@@ -207,6 +271,7 @@ static const struct rockchip_pwm_data pwm_data_v2 = {
 	.prescaler = 1,
 	.ops = &rockchip_pwm_ops_v2,
 	.set_enable = rockchip_pwm_set_enable_v2,
+	.reset_state = rockchip_pwm_reset_state_v2,
 };
 
 static const struct rockchip_pwm_data pwm_data_vop = {
@@ -219,6 +284,7 @@ static const struct rockchip_pwm_data pwm_data_vop = {
 	.prescaler = 1,
 	.ops = &rockchip_pwm_ops_v2,
 	.set_enable = rockchip_pwm_set_enable_v2,
+	.reset_state = rockchip_pwm_reset_state_v2,
 };
 
 static const struct of_device_id rockchip_pwm_dt_ids[] = {
-- 
2.1.4

[PATCH v4 24/24] regulator: pwm: properly initialize the ->state field

[Boris Brezillon]

The ->state field is currently initialized to 0, thus referencing the
voltage selector at index 0, which might not reflect the current voltage
value.
If possible, retrieve the current voltage selector from the PWM state, else
return -EINVAL.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Tested-by: Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
Acked-by: Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
---
 drivers/regulator/pwm-regulator.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
index 9ffdbd6..449e3b3 100644
--- a/drivers/regulator/pwm-regulator.c
+++ b/drivers/regulator/pwm-regulator.c
@@ -41,10 +41,35 @@ struct pwm_voltages {
 /**
  * Voltage table call-backs
  */
+static void pwm_regulator_init_state(struct regulator_dev *rdev)
+{
+	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
+	struct pwm_state pwm_state;
+	unsigned int dutycycle;
+	int i;
+
+	pwm_get_state(drvdata->pwm, &pwm_state);
+
+	if (!pwm_state.period)
+		return;
+
+	dutycycle = (pwm_state.duty_cycle * 100) / pwm_state.period;
+
+	for (i = 0; i < rdev->desc->n_voltages; i++) {
+		if (dutycycle == drvdata->duty_cycle_table[i].dutycycle) {
+			drvdata->state = i;
+			return;
+		}
+	}
+}
+
 static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
 
+	if (drvdata->state < 0)
+		pwm_regulator_init_state(rdev);
+
 	return drvdata->state;
 }
 
@@ -211,6 +236,7 @@ static int pwm_regulator_init_table(struct platform_device *pdev,
 		return ret;
 	}
 
+	drvdata->state			= -EINVAL;
 	drvdata->duty_cycle_table	= duty_cycle_table;
 	pwm_regulator_desc.ops		= &pwm_regulator_voltage_table_ops;
 	pwm_regulator_desc.n_voltages	= length / sizeof(*duty_cycle_table);
-- 
2.1.4

Re: [PATCH v4 00/24] pwm: add support for atomic update

[Heiko Stübner]

Hi Boris,

Am Montag, 16. November 2015, 09:56:23 schrieb Boris Brezillon:
> Hello,
> 
> This series adds support for atomic PWM update, or IOW, the capability
> to update all the parameters of a PWM device (enabled/disabled, period,
> duty and polarity) in one go.

you already include my tested-by tags, but anyway, the series still works 
nicely on 4.4-rc1 on my veyron chromebook.


Heiko

[PATCH v4 20/24] pwm: add the core infrastructure to allow atomic update

[Boris Brezillon]

Add an ->apply() method to the pwm_ops struct to allow PWM drivers to
implement atomic update.
This method will be preferred over the ->enable(), ->disable() and
->config() methods if available.

Add the pwm_get_state(), pwm_get_default_state() and pwm_apply_state()
functions for PWM users to be able to use the atomic update feature.

Note that the pwm_apply_state() does not guarantee the atomicity of the
update operation, it all depends on the availability and implementation
of the ->apply() method.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
---
 drivers/pwm/core.c  | 124 +++++++++++++++++++++++++++++++++++++++++++++++++---
 include/linux/pwm.h |  27 ++++++++++++
 2 files changed, 146 insertions(+), 5 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index ce8b373..fbc71d3 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -46,6 +46,12 @@ static struct pwm_device *pwm_to_device(unsigned int pwm)
 	return radix_tree_lookup(&pwm_tree, pwm);
 }
 
+static void pwm_set_state(struct pwm_device *pwm,
+			  const struct pwm_state *state)
+{
+	pwm->state = *state;
+}
+
 static int alloc_pwms(int pwm, unsigned int count)
 {
 	unsigned int from = 0;
@@ -226,6 +232,19 @@ void *pwm_get_chip_data(struct pwm_device *pwm)
 }
 EXPORT_SYMBOL_GPL(pwm_get_chip_data);
 
+static bool pwm_ops_check(const struct pwm_ops *ops)
+{
+	/* driver supports legacy, non-atomic operation */
+	if (ops->config && ops->enable && ops->disable)
+		return true;
+
+	/* driver supports atomic operation */
+	if (ops->apply)
+		return true;
+
+	return false;
+}
+
 /**
  * pwmchip_add_with_polarity() - register a new PWM chip
  * @chip: the PWM chip to add
@@ -244,8 +263,10 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
 	unsigned int i;
 	int ret;
 
-	if (!chip || !chip->dev || !chip->ops || !chip->ops->config ||
-	    !chip->ops->enable || !chip->ops->disable || !chip->npwm)
+	if (!chip || !chip->dev || !chip->ops || !chip->npwm)
+		return -EINVAL;
+
+	if (!pwm_ops_check(chip->ops))
 		return -EINVAL;
 
 	mutex_lock(&pwm_lock);
@@ -446,7 +467,19 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
 	if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns)
 		return -EINVAL;
 
-	err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns);
+	if (pwm->chip->ops->apply) {
+		struct pwm_state state;
+
+		pwm_get_state(pwm, &state);
+		state.period = period_ns;
+		state.duty_cycle = duty_ns;
+
+		err = pwm->chip->ops->apply(pwm->chip, pwm, &state);
+	} else {
+		err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns,
+					     period_ns);
+	}
+
 	if (err)
 		return err;
 
@@ -474,6 +507,18 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
 	if (!pwm || !pwm->chip->ops)
 		return -EINVAL;
 
+	if (pwm->chip->ops->apply) {
+		struct pwm_state state;
+
+		pwm_get_state(pwm, &state);
+		state.polarity = polarity;
+		err = pwm->chip->ops->apply(pwm->chip, pwm, &state);
+		if (!err)
+			pwm->state.polarity = polarity;
+
+		return err;
+	}
+
 	if (!pwm->chip->ops->set_polarity)
 		return -ENOSYS;
 
@@ -512,7 +557,17 @@ int pwm_enable(struct pwm_device *pwm)
 	mutex_lock(&pwm->lock);
 
 	if (!pwm_is_enabled(pwm)) {
-		err = pwm->chip->ops->enable(pwm->chip, pwm);
+		if (pwm->chip->ops->apply) {
+			struct pwm_state state;
+
+			pwm_get_state(pwm, &state);
+			state.enabled = true;
+
+			err = pwm->chip->ops->apply(pwm->chip, pwm, &state);
+		} else {
+			err = pwm->chip->ops->enable(pwm->chip, pwm);
+		}
+
 		if (!err)
 			pwm->state.enabled = true;
 	}
@@ -535,7 +590,16 @@ void pwm_disable(struct pwm_device *pwm)
 	mutex_lock(&pwm->lock);
 
 	if (pwm_is_enabled(pwm)) {
-		pwm->chip->ops->disable(pwm->chip, pwm);
+		if (pwm->chip->ops->apply) {
+			struct pwm_state state;
+
+			pwm_get_state(pwm, &state);
+			state.enabled = false;
+
+			pwm->chip->ops->apply(pwm->chip, pwm, &state);
+		} else {
+			pwm->chip->ops->disable(pwm->chip, pwm);
+		}
 		pwm->state.enabled = false;
 	}
 
@@ -543,6 +607,56 @@ void pwm_disable(struct pwm_device *pwm)
 }
 EXPORT_SYMBOL_GPL(pwm_disable);
 
+/**
+ * pwm_apply_state() - atomically apply a new state to a PWM device
+ * @pwm: PWM device
+ * @state: new state to apply
+ */
+int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state)
+{
+	int err = 0;
+
+	if (!pwm)
+		return -EINVAL;
+
+	if (!memcmp(state, &pwm->state, sizeof(*state)))
+		return 0;
+
+	if (pwm->chip->ops->apply) {
+		err = pwm->chip->ops->apply(pwm->chip, pwm, state);
+		if (!err)
+			pwm_set_state(pwm, state);
+	} else {
+		/*
+		 * FIXME: restore the initial state in case of error.
+		 */
+		if (state->polarity != pwm->state.polarity) {
+			pwm_disable(pwm);
+			err = pwm_set_polarity(pwm, state->polarity);
+			if (err)
+				goto out;
+		}
+
+		if (state->period != pwm->state.period ||
+		    state->duty_cycle != pwm->state.duty_cycle) {
+			err = pwm_config(pwm, state->period, state->duty_cycle);
+			if (err)
+				goto out;
+		}
+
+		if (state->enabled != pwm->state.enabled) {
+			if (state->enabled)
+				err = pwm_enable(pwm);
+			else
+				pwm_disable(pwm);
+		}
+	}
+
+out:
+	return err;
+}
+EXPORT_SYMBOL_GPL(pwm_apply_state);
+
 static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
 {
 	struct pwm_chip *chip;
diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index caa0ffe..5e7b378 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -174,6 +174,30 @@ static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
 	return pwm ? pwm->state.polarity : PWM_POLARITY_NORMAL;
 }
 
+int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state);
+
+/**
+ * pwm_get_state() - retrieve the current PWM state
+ * @pwm: PWM device
+ * @state: state to fill with the current PWM state
+ */
+static inline void pwm_get_state(struct pwm_device *pwm,
+				 struct pwm_state *state)
+{
+	*state = pwm->state;
+}
+
+/**
+ * pwm_get_default_state() - retrieve the default PWM state
+ * @pwm: PWM device
+ * @state: state to fill with the default PWM state
+ */
+static inline void pwm_get_default_state(struct pwm_device *pwm,
+					 struct pwm_state *state)
+{
+	*state = pwm->default_state;
+}
+
 /**
  * struct pwm_ops - PWM controller operations
  * @request: optional hook for requesting a PWM
@@ -182,6 +206,7 @@ static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
  * @set_polarity: configure the polarity of this PWM
  * @enable: enable PWM output toggling
  * @disable: disable PWM output toggling
+ * @apply: atomically apply a new PWM config
  * @reset_state: reset the current PWM state (pwm->state) to the actual
  *		 hardware state. This function is only called once per
  *		 PWM device when the PWM chip is registered.
@@ -197,6 +222,8 @@ struct pwm_ops {
 			    enum pwm_polarity polarity);
 	int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm);
 	void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm);
+	int (*apply)(struct pwm_chip *chip, struct pwm_device *pwm,
+		     const struct pwm_state *state);
 	void (*reset_state)(struct pwm_chip *chip, struct pwm_device *pwm);
 #ifdef CONFIG_DEBUG_FS
 	void (*dbg_show)(struct pwm_chip *chip, struct seq_file *s);
-- 
2.1.4

[PATCH v4 21/24] pwm: add information about polarity, duty cycle and period to debugfs

[Boris Brezillon]

From: Heiko Stübner <heiko@sntech.de>

The pwm-states make it possible to also output the polarity, duty cycle
and period information in the debugfs pwm summary-outout.
This makes it easier to gather overview information about pwms without
needing to walk through the sysfs attributes of every pwm.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
 drivers/pwm/core.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index fbc71d3..1619101 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -1035,6 +1035,11 @@ static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
 		if (pwm_is_enabled(pwm))
 			seq_puts(s, " enabled");
 
+		seq_printf(s, " period:%uns", pwm_get_period(pwm));
+		seq_printf(s, " duty:%uns", pwm_get_duty_cycle(pwm));
+		seq_printf(s, " polarity:%s", pwm_get_polarity(pwm) ? "inverse"
+								    : "normal");
+
 		seq_puts(s, "\n");
 	}
 }
-- 
2.1.4

[PATCH v4 23/24] pwm: rockchip: add support for atomic update

[Boris Brezillon]

Implement the ->apply() function to add support for atomic update.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
---
 drivers/pwm/pwm-rockchip.c | 53 +++++++++++++++++++++++++---------------------
 1 file changed, 29 insertions(+), 24 deletions(-)

diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
index 6eab25c..48b814d 100644
--- a/drivers/pwm/pwm-rockchip.c
+++ b/drivers/pwm/pwm-rockchip.c
@@ -50,7 +50,8 @@ struct rockchip_pwm_data {
 	const struct pwm_ops *ops;
 
 	void (*set_enable)(struct pwm_chip *chip,
-			   struct pwm_device *pwm, bool enable);
+			   struct pwm_device *pwm, bool enable,
+			   enum pwm_polarity polarity);
 	void (*reset_state)(struct pwm_chip *chip, struct pwm_device *pwm);
 };
 
@@ -60,7 +61,8 @@ static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
 }
 
 static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip,
-				       struct pwm_device *pwm, bool enable)
+				       struct pwm_device *pwm, bool enable,
+				       enum pwm_polarity polarity)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
 	u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
@@ -89,14 +91,15 @@ static void rockchip_pwm_reset_state_v1(struct pwm_chip *chip,
 }
 
 static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
-				       struct pwm_device *pwm, bool enable)
+				       struct pwm_device *pwm, bool enable,
+				       enum pwm_polarity polarity)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
 	u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
 			  PWM_CONTINUOUS;
 	u32 val;
 
-	if (pwm_get_polarity(pwm) == PWM_POLARITY_INVERSED)
+	if (polarity == PWM_POLARITY_INVERSED)
 		enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
 	else
 		enable_conf |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;
@@ -165,7 +168,6 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
 	unsigned long period, duty;
 	u64 clk_rate, div;
-	int ret;
 
 	clk_rate = clk_get_rate(pc->clk);
 
@@ -182,15 +184,8 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	do_div(div, pc->data->prescaler * NSEC_PER_SEC);
 	duty = div;
 
-	ret = clk_enable(pc->clk);
-	if (ret)
-		return ret;
-
 	writel(period, pc->base + pc->data->regs.period);
 	writel(duty, pc->base + pc->data->regs.duty);
-	writel(0, pc->base + pc->data->regs.cntr);
-
-	clk_disable(pc->clk);
 
 	return 0;
 }
@@ -208,43 +203,53 @@ static int rockchip_pwm_set_polarity(struct pwm_chip *chip,
 	return 0;
 }
 
-static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			      const struct pwm_state *state)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	bool enabled = pwm_is_enabled(pwm);
 	int ret;
 
 	ret = clk_enable(pc->clk);
 	if (ret)
 		return ret;
 
-	pc->data->set_enable(chip, pwm, true);
+	if (state->polarity != pwm_get_polarity(pwm) && enabled) {
+		pc->data->set_enable(chip, pwm, false, state->polarity);
+		enabled = false;
+	}
 
-	return 0;
-}
+	ret = rockchip_pwm_config(chip, pwm, state->duty_cycle, state->period);
+	if (ret) {
+		if (enabled != pwm_is_enabled(pwm))
+			pc->data->set_enable(chip, pwm, !enabled,
+					     state->polarity);
 
-static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
-	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+		goto out;
+	}
 
-	pc->data->set_enable(chip, pwm, false);
+	if (state->enabled != enabled)
+		pc->data->set_enable(chip, pwm, state->enabled,
+				     state->polarity);
 
+out:
 	clk_disable(pc->clk);
+
+	return ret;
 }
 
 static const struct pwm_ops rockchip_pwm_ops_v1 = {
 	.reset_state = rockchip_pwm_reset_state,
 	.config = rockchip_pwm_config,
-	.enable = rockchip_pwm_enable,
-	.disable = rockchip_pwm_disable,
+	.apply = rockchip_pwm_apply,
 	.owner = THIS_MODULE,
 };
 
 static const struct pwm_ops rockchip_pwm_ops_v2 = {
 	.reset_state = rockchip_pwm_reset_state,
 	.config = rockchip_pwm_config,
+	.apply = rockchip_pwm_apply,
 	.set_polarity = rockchip_pwm_set_polarity,
-	.enable = rockchip_pwm_enable,
-	.disable = rockchip_pwm_disable,
 	.owner = THIS_MODULE,
 };
 
-- 
2.1.4

Re: [PATCH v4 00/24] pwm: add support for atomic update

[Heiko Stübner]

Hi Boris,

Am Montag, 16. November 2015, 09:56:23 schrieb Boris Brezillon:
> Hello,
> 
> This series adds support for atomic PWM update, or IOW, the capability
> to update all the parameters of a PWM device (enabled/disabled, period,
> duty and polarity) in one go.

you already include my tested-by tags, but anyway, the series still works 
nicely on 4.4-rc1 on my veyron chromebook.


Heiko

Re: [PATCH v4 00/24] pwm: add support for atomic update

[Heiko Stübner]

Hi Boris,

Am Montag, 16. November 2015, 09:56:23 schrieb Boris Brezillon:
> Hello,
> 
> This series adds support for atomic PWM update, or IOW, the capability
> to update all the parameters of a PWM device (enabled/disabled, period,
> duty and polarity) in one go.

you already include my tested-by tags, but anyway, the series still works 
nicely on 4.4-rc1 on my veyron chromebook.


Heiko

Re: [PATCH v4 00/24] pwm: add support for atomic update

[Heiko Stübner]

Hi Boris,

Am Montag, 16. November 2015, 09:56:23 schrieb Boris Brezillon:
> Hello,
> 
> This series adds support for atomic PWM update, or IOW, the capability
> to update all the parameters of a PWM device (enabled/disabled, period,
> duty and polarity) in one go.

you already include my tested-by tags, but anyway, the series still works 
nicely on 4.4-rc1 on my veyron chromebook.


Heiko

Re: [PATCH v4 00/24] pwm: add support for atomic update

[Heiko Stübner]

Hi Boris,

Am Montag, 16. November 2015, 09:56:23 schrieb Boris Brezillon:
> Hello,
> 
> This series adds support for atomic PWM update, or IOW, the capability
> to update all the parameters of a PWM device (enabled/disabled, period,
> duty and polarity) in one go.

you already include my tested-by tags, but anyway, the series still works 
nicely on 4.4-rc1 on my veyron chromebook.


Heiko

Re: [PATCH v4 00/24] pwm: add support for atomic update

[Heiko Stübner]

Hi Boris,

Am Montag, 16. November 2015, 09:56:23 schrieb Boris Brezillon:
> Hello,
> 
> This series adds support for atomic PWM update, or IOW, the capability
> to update all the parameters of a PWM device (enabled/disabled, period,
> duty and polarity) in one go.

you already include my tested-by tags, but anyway, the series still works 
nicely on 4.4-rc1 on my veyron chromebook.


Heiko

Re: [PATCH v4 00/24] pwm: add support for atomic update

[Heiko Stübner]

Hi Boris,

Am Montag, 16. November 2015, 09:56:23 schrieb Boris Brezillon:
> Hello,
> 
> This series adds support for atomic PWM update, or IOW, the capability
> to update all the parameters of a PWM device (enabled/disabled, period,
> duty and polarity) in one go.

you already include my tested-by tags, but anyway, the series still works 
nicely on 4.4-rc1 on my veyron chromebook.


Heiko