Re: [PATCH v3 01/12] pwm: introduce default period and polarity concepts

From: Lee Jones
Date: Tue Sep 22 2015 - 17:49:45 EST


On Mon, 21 Sep 2015, Boris Brezillon wrote:

> 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.
>
> This patch also modifies all the places where the default helpers should
> be used in place of the standard ones.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/leds/leds-pwm.c | 2 +-
> drivers/pwm/core.c | 14 +++++++-------
> drivers/pwm/pwm-pxa.c | 2 +-
> drivers/pwm/pwm-sun4i.c | 3 ++-
> drivers/regulator/pwm-regulator.c | 4 ++--
> drivers/video/backlight/lm3630a_bl.c | 4 ++--
> drivers/video/backlight/pwm_bl.c | 2 +-

Acked-by: Lee Jones <lee.jones@xxxxxxxxxx>

> drivers/video/fbdev/ssd1307fb.c | 2 +-
> include/linux/pwm.h | 17 +++++++++++++++++
> 9 files changed, 34 insertions(+), 16 deletions(-)
>
> 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;
>
> diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
> index 3f9df3e..732375d 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);
>
> radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
> }
> @@ -730,8 +730,8 @@ 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 cd9dde5..a364fb7 100644
> --- a/drivers/pwm/pwm-sun4i.c
> +++ b/drivers/pwm/pwm-sun4i.c
> @@ -333,7 +333,8 @@ 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;
> diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
> index fc3166d..cc549b7 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;
> @@ -114,7 +114,7 @@ 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;
>
> 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 eff379b..ae498c1 100644
> --- a/drivers/video/backlight/pwm_bl.c
> +++ b/drivers/video/backlight/pwm_bl.c
> @@ -294,7 +294,7 @@ 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);
> diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
> index 93f4c90..ab3daf0 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);
> diff --git a/include/linux/pwm.h b/include/linux/pwm.h
> index d681f68..31239a9 100644
> --- a/include/linux/pwm.h
> +++ b/include/linux/pwm.h
> @@ -115,11 +115,22 @@ 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)
> @@ -136,6 +147,12 @@ 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;

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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