[PATCH v2 1/2] pwm: lpss: Release runtime-pm reference from the driver's remove callback

[PATCH v2 1/2] pwm: lpss: Release runtime-pm reference from the driver's remove callback

[Hans de Goede]

For each pwm output which gets enabled through pwm_lpss_apply(), we do a
pm_runtime_get_sync().

This commit adds pm_runtime_put() calls to pwm_lpss_remove() to balance
these when the driver gets removed with some of the outputs still enabled.

Fixes: f080be27d7d9 ("pwm: lpss: Add support for runtime PM")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v2:
-New patch in v2 of this patch-set replacing "pwm: lpss: Add
 pwm_lpss_get_put_runtime_pm helper function"
---
 drivers/pwm/pwm-lpss.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index e602835fd6de..723ca9de8325 100644
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -205,6 +205,12 @@ EXPORT_SYMBOL_GPL(pwm_lpss_probe);
 
 int pwm_lpss_remove(struct pwm_lpss_chip *lpwm)
 {
+	int i;
+
+	for (i = 0; i < lpwm->info->npwm; i++) {
+		if (pwm_is_enabled(&lpwm->chip.pwms[i]))
+			pm_runtime_put(lpwm->chip.dev);
+	}
 	return pwmchip_remove(&lpwm->chip);
 }
 EXPORT_SYMBOL_GPL(pwm_lpss_remove);
-- 
2.19.0.rc1

[PATCH v2 2/2] pwm: lpss: Add get_state callback

[Hans de Goede]

Add a get_state callback so that the initial state correctly reflects
the actual hardware state.

Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v2:
-Stop using the dropped pwm_lpss_get_put_runtime_pm() helper
---
 drivers/pwm/pwm-lpss.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index 723ca9de8325..ea93ef9f3672 100644
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -159,8 +159,42 @@ static int pwm_lpss_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	return 0;
 }
 
+/* This function gets called once from pwmchip_add to get the initial state */
+static void pwm_lpss_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+			       struct pwm_state *state)
+{
+	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
+	unsigned long base_unit_range;
+	unsigned long long base_unit, freq, on_time_div;
+	u32 ctrl;
+
+	base_unit_range = BIT(lpwm->info->base_unit_bits);
+
+	ctrl = pwm_lpss_read(pwm);
+	on_time_div = 255 - (ctrl & PWM_ON_TIME_DIV_MASK);
+	base_unit = (ctrl >> PWM_BASE_UNIT_SHIFT) & (base_unit_range - 1);
+
+	freq = base_unit * lpwm->info->clk_rate;
+	do_div(freq, base_unit_range);
+	if (freq == 0)
+		state->period = NSEC_PER_SEC;
+	else
+		state->period = NSEC_PER_SEC / (unsigned long)freq;
+
+	on_time_div *= state->period;
+	do_div(on_time_div, 255);
+	state->duty_cycle = on_time_div;
+
+	state->polarity = PWM_POLARITY_NORMAL;
+	state->enabled = !!(ctrl & PWM_ENABLE);
+
+	if (state->enabled)
+		pm_runtime_get(chip->dev);
+}
+
 static const struct pwm_ops pwm_lpss_ops = {
 	.apply = pwm_lpss_apply,
+	.get_state = pwm_lpss_get_state,
 	.owner = THIS_MODULE,
 };
 
-- 
2.19.0.rc1

Re: [PATCH v2 1/2] pwm: lpss: Release runtime-pm reference from the driver's remove callback

[Andy Shevchenko]

On Tue, Sep 25, 2018 at 09:25:35AM +0200, Hans de Goede wrote:
> For each pwm output which gets enabled through pwm_lpss_apply(), we do a
> pm_runtime_get_sync().
> 
> This commit adds pm_runtime_put() calls to pwm_lpss_remove() to balance
> these when the driver gets removed with some of the outputs still enabled.

Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> 
> Fixes: f080be27d7d9 ("pwm: lpss: Add support for runtime PM")
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> Changes in v2:
> -New patch in v2 of this patch-set replacing "pwm: lpss: Add
>  pwm_lpss_get_put_runtime_pm helper function"
> ---
>  drivers/pwm/pwm-lpss.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
> index e602835fd6de..723ca9de8325 100644
> --- a/drivers/pwm/pwm-lpss.c
> +++ b/drivers/pwm/pwm-lpss.c
> @@ -205,6 +205,12 @@ EXPORT_SYMBOL_GPL(pwm_lpss_probe);
>  
>  int pwm_lpss_remove(struct pwm_lpss_chip *lpwm)
>  {
> +	int i;
> +
> +	for (i = 0; i < lpwm->info->npwm; i++) {
> +		if (pwm_is_enabled(&lpwm->chip.pwms[i]))
> +			pm_runtime_put(lpwm->chip.dev);
> +	}
>  	return pwmchip_remove(&lpwm->chip);
>  }
>  EXPORT_SYMBOL_GPL(pwm_lpss_remove);
> -- 
> 2.19.0.rc1
> 

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2 2/2] pwm: lpss: Add get_state callback

[Andy Shevchenko]

On Tue, Sep 25, 2018 at 09:25:36AM +0200, Hans de Goede wrote:
> Add a get_state callback so that the initial state correctly reflects
> the actual hardware state.
> 

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Acked-by: Jani Nikula <jani.nikula@intel.com>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> Changes in v2:
> -Stop using the dropped pwm_lpss_get_put_runtime_pm() helper
> ---
>  drivers/pwm/pwm-lpss.c | 34 ++++++++++++++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
> 
> diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
> index 723ca9de8325..ea93ef9f3672 100644
> --- a/drivers/pwm/pwm-lpss.c
> +++ b/drivers/pwm/pwm-lpss.c
> @@ -159,8 +159,42 @@ static int pwm_lpss_apply(struct pwm_chip *chip, struct pwm_device *pwm,
>  	return 0;
>  }
>  
> +/* This function gets called once from pwmchip_add to get the initial state */
> +static void pwm_lpss_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
> +			       struct pwm_state *state)
> +{
> +	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
> +	unsigned long base_unit_range;
> +	unsigned long long base_unit, freq, on_time_div;
> +	u32 ctrl;
> +
> +	base_unit_range = BIT(lpwm->info->base_unit_bits);
> +
> +	ctrl = pwm_lpss_read(pwm);
> +	on_time_div = 255 - (ctrl & PWM_ON_TIME_DIV_MASK);
> +	base_unit = (ctrl >> PWM_BASE_UNIT_SHIFT) & (base_unit_range - 1);
> +
> +	freq = base_unit * lpwm->info->clk_rate;
> +	do_div(freq, base_unit_range);
> +	if (freq == 0)
> +		state->period = NSEC_PER_SEC;
> +	else
> +		state->period = NSEC_PER_SEC / (unsigned long)freq;
> +
> +	on_time_div *= state->period;
> +	do_div(on_time_div, 255);
> +	state->duty_cycle = on_time_div;
> +
> +	state->polarity = PWM_POLARITY_NORMAL;
> +	state->enabled = !!(ctrl & PWM_ENABLE);
> +
> +	if (state->enabled)
> +		pm_runtime_get(chip->dev);
> +}
> +
>  static const struct pwm_ops pwm_lpss_ops = {
>  	.apply = pwm_lpss_apply,
> +	.get_state = pwm_lpss_get_state,
>  	.owner = THIS_MODULE,
>  };
>  
> -- 
> 2.19.0.rc1
> 

-- 
With Best Regards,
Andy Shevchenko