diff mbox

[v2,1/2] power: regulator: pwm: support pwm polarity setting

Message ID 1491899738-10087-1-git-send-email-kever.yang@rock-chips.com (mailing list archive)
State New, archived
Headers show

Commit Message

Kever Yang April 11, 2017, 8:35 a.m. UTC 
The latest kernel PWM drivers enable the polarity settings. When system
run from U-Boot to kerenl, if there are differences in polarity set or
duty cycle, the PMW will re-init:
  close -> set polarity and duty cycle -> enable the PWM.
The power supply controled by pwm regulator may have voltage shaking,
which lead to the system not stable.

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
---

Changes in v2:
- use pwm_set_invert() instead of pwm_set_init()
- add comment for polarity

 drivers/power/regulator/pwm_regulator.c | 16 ++++++++++++++--
 drivers/pwm/pwm-uclass.c                | 10 ++++++++++
 drivers/pwm/rk_pwm.c                    | 17 ++++++++++++++++-
 include/pwm.h                           |  9 +++++++++
 4 files changed, 49 insertions(+), 3 deletions(-)

Comments

Simon Glass April 15, 2017, 11:39 p.m. UTC | #1 
Hi Kever,

On 11 April 2017 at 02:35, Kever Yang <kever.yang@rock-chips.com> wrote:
> The latest kernel PWM drivers enable the polarity settings. When system
> run from U-Boot to kerenl, if there are differences in polarity set or
> duty cycle, the PMW will re-init:
>   close -> set polarity and duty cycle -> enable the PWM.
> The power supply controled by pwm regulator may have voltage shaking,
> which lead to the system not stable.
>
> Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
> Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
> ---
>
> Changes in v2:
> - use pwm_set_invert() instead of pwm_set_init()
> - add comment for polarity
>
>  drivers/power/regulator/pwm_regulator.c | 16 ++++++++++++++--
>  drivers/pwm/pwm-uclass.c                | 10 ++++++++++
>  drivers/pwm/rk_pwm.c                    | 17 ++++++++++++++++-
>  include/pwm.h                           |  9 +++++++++
>  4 files changed, 49 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/power/regulator/pwm_regulator.c b/drivers/power/regulator/pwm_regulator.c
> index 4875238..3ffe3a1 100644
> --- a/drivers/power/regulator/pwm_regulator.c
> +++ b/drivers/power/regulator/pwm_regulator.c
> @@ -24,6 +24,12 @@ struct pwm_regulator_info {
>         int pwm_id;
>         /* the period of one PWM cycle */
>         int period_ns;
> +       /*
> +        * the polarity of one PWM
> +        * 0: normal polarity
> +        * 1: inverted polarity
> +        */
> +       int polarity;
>         struct udevice *pwm;
>         /* initialize voltage of regulator */
>         unsigned int init_voltage;
> @@ -49,7 +55,7 @@ static int pwm_voltage_to_duty_cycle_percentage(struct udevice *dev, int req_uV)
>         int max_uV = priv->max_voltage;
>         int diff = max_uV - min_uV;
>
> -       return 100 - (((req_uV * 100) - (min_uV * 100)) / diff);
> +       return ((req_uV * 100) - (min_uV * 100)) / diff;
>  }
>
>  static int pwm_regulator_get_voltage(struct udevice *dev)
> @@ -67,6 +73,12 @@ static int pwm_regulator_set_voltage(struct udevice *dev, int uvolt)
>
>         duty_cycle = pwm_voltage_to_duty_cycle_percentage(dev, uvolt);
>
> +       ret = pwm_set_invert(priv->pwm, priv->pwm_id, priv->polarity);
> +       if (ret) {
> +               dev_err(dev, "Failed to init PWM\n");
> +               return ret;
> +       }
> +
>         ret = pwm_set_config(priv->pwm, priv->pwm_id,
>                         (priv->period_ns / 100) * duty_cycle, priv->period_ns);
>         if (ret) {
> @@ -97,9 +109,9 @@ static int pwm_regulator_ofdata_to_platdata(struct udevice *dev)
>                 debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret);
>                 return ret;
>         }
> -       /* TODO: pwm_id here from device tree if needed */
>
>         priv->period_ns = args.args[1];
> +       priv->polarity = args.args[2];
>
>         priv->init_voltage = fdtdec_get_int(blob, node,
>                         "regulator-init-microvolt", -1);
> diff --git a/drivers/pwm/pwm-uclass.c b/drivers/pwm/pwm-uclass.c
> index c2200af..d1d7fce 100644
> --- a/drivers/pwm/pwm-uclass.c
> +++ b/drivers/pwm/pwm-uclass.c
> @@ -9,6 +9,16 @@
>  #include <dm.h>
>  #include <pwm.h>
>
> +int pwm_set_invert(struct udevice *dev, uint channel, uint polarity)
> +{
> +       struct pwm_ops *ops = pwm_get_ops(dev);
> +
> +       if (!ops->set_invert)
> +               return -ENOSYS;
> +
> +       return ops->set_invert(dev, channel, polarity);
> +}
> +
>  int pwm_set_config(struct udevice *dev, uint channel, uint period_ns,
>                    uint duty_ns)
>  {
> diff --git a/drivers/pwm/rk_pwm.c b/drivers/pwm/rk_pwm.c
> index 9254f5b..f003d09 100644
> --- a/drivers/pwm/rk_pwm.c
> +++ b/drivers/pwm/rk_pwm.c
> @@ -21,8 +21,22 @@ DECLARE_GLOBAL_DATA_PTR;
>  struct rk_pwm_priv {
>         struct rk3288_pwm *regs;
>         ulong freq;
> +       uint enable_conf;
>  };
>
> +static int rk_pwm_set_invert(struct udevice *dev, uint channel, uint polarity)
> +{
> +       struct rk_pwm_priv *priv = dev_get_priv(dev);
> +
> +       debug("%s: polarity=%u\n", __func__, polarity);
> +       if (polarity)
> +               priv->enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSTIVE;
> +       else
> +               priv->enable_conf |= PWM_DUTY_POSTIVE | PWM_INACTIVE_NEGATIVE;
> +
> +       return 0;
> +}
> +
>  static int rk_pwm_set_config(struct udevice *dev, uint channel, uint period_ns,
>                              uint duty_ns)
>  {
> @@ -32,7 +46,7 @@ static int rk_pwm_set_config(struct udevice *dev, uint channel, uint period_ns,
>
>         debug("%s: period_ns=%u, duty_ns=%u\n", __func__, period_ns, duty_ns);
>         writel(PWM_SEL_SRC_CLK | PWM_OUTPUT_LEFT | PWM_LP_DISABLE |
> -               PWM_CONTINUOUS | PWM_DUTY_POSTIVE | PWM_INACTIVE_POSTIVE |
> +               PWM_CONTINUOUS | priv->enable_conf |
>                 RK_PWM_DISABLE,
>                 &regs->ctrl);
>
> @@ -83,6 +97,7 @@ static int rk_pwm_probe(struct udevice *dev)
>  }
>
>  static const struct pwm_ops rk_pwm_ops = {
> +       .set_invert     = rk_pwm_set_invert,
>         .set_config     = rk_pwm_set_config,
>         .set_enable     = rk_pwm_set_enable,
>  };
> diff --git a/include/pwm.h b/include/pwm.h
> index 851915e..66c6bf0 100644
> --- a/include/pwm.h
> +++ b/include/pwm.h
> @@ -14,6 +14,15 @@
>  /* struct pwm_ops: Operations for the PWM uclass */
>  struct pwm_ops {
>         /**
> +        * set_invert() - Set the PWM invert
> +        *
> +        * @dev:        PWM device to update
> +        * @channel:    PWM channel to update
> +        * @polarity:  PWM invert polarity

Please document the meaning of this parameter.

> +        * @return 0 if OK, -ve on error
> +        */
> +       int (*set_invert)(struct udevice *dev, uint channel, uint polarity);
> +       /**
>          * set_config() - Set the PWM configuration
>          *
>          * @dev:        PWM device to update
> --
> 1.9.1
>

Can you also please write a test in test/dm/pwm.c with a sandbox pwm
driver? A recent example is:

http://patchwork.ozlabs.org/patch/750796/

Regards,
Simon
diff mbox

Patch

diff --git a/drivers/power/regulator/pwm_regulator.c b/drivers/power/regulator/pwm_regulator.c
index 4875238..3ffe3a1 100644
--- a/drivers/power/regulator/pwm_regulator.c
+++ b/drivers/power/regulator/pwm_regulator.c
@@ -24,6 +24,12 @@  struct pwm_regulator_info {
 	int pwm_id;
 	/* the period of one PWM cycle */
 	int period_ns;
+	/*
+	 * the polarity of one PWM
+	 * 0: normal polarity
+	 * 1: inverted polarity
+	 */
+	int polarity;
 	struct udevice *pwm;
 	/* initialize voltage of regulator */
 	unsigned int init_voltage;
@@ -49,7 +55,7 @@  static int pwm_voltage_to_duty_cycle_percentage(struct udevice *dev, int req_uV)
 	int max_uV = priv->max_voltage;
 	int diff = max_uV - min_uV;
 
-	return 100 - (((req_uV * 100) - (min_uV * 100)) / diff);
+	return ((req_uV * 100) - (min_uV * 100)) / diff;
 }
 
 static int pwm_regulator_get_voltage(struct udevice *dev)
@@ -67,6 +73,12 @@  static int pwm_regulator_set_voltage(struct udevice *dev, int uvolt)
 
 	duty_cycle = pwm_voltage_to_duty_cycle_percentage(dev, uvolt);
 
+	ret = pwm_set_invert(priv->pwm, priv->pwm_id, priv->polarity);
+	if (ret) {
+		dev_err(dev, "Failed to init PWM\n");
+		return ret;
+	}
+
 	ret = pwm_set_config(priv->pwm, priv->pwm_id,
 			(priv->period_ns / 100) * duty_cycle, priv->period_ns);
 	if (ret) {
@@ -97,9 +109,9 @@  static int pwm_regulator_ofdata_to_platdata(struct udevice *dev)
 		debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret);
 		return ret;
 	}
-	/* TODO: pwm_id here from device tree if needed */
 
 	priv->period_ns = args.args[1];
+	priv->polarity = args.args[2];
 
 	priv->init_voltage = fdtdec_get_int(blob, node,
 			"regulator-init-microvolt", -1);
diff --git a/drivers/pwm/pwm-uclass.c b/drivers/pwm/pwm-uclass.c
index c2200af..d1d7fce 100644
--- a/drivers/pwm/pwm-uclass.c
+++ b/drivers/pwm/pwm-uclass.c
@@ -9,6 +9,16 @@ 
 #include <dm.h>
 #include <pwm.h>
 
+int pwm_set_invert(struct udevice *dev, uint channel, uint polarity)
+{
+	struct pwm_ops *ops = pwm_get_ops(dev);
+
+	if (!ops->set_invert)
+		return -ENOSYS;
+
+	return ops->set_invert(dev, channel, polarity);
+}
+
 int pwm_set_config(struct udevice *dev, uint channel, uint period_ns,
 		   uint duty_ns)
 {
diff --git a/drivers/pwm/rk_pwm.c b/drivers/pwm/rk_pwm.c
index 9254f5b..f003d09 100644
--- a/drivers/pwm/rk_pwm.c
+++ b/drivers/pwm/rk_pwm.c
@@ -21,8 +21,22 @@  DECLARE_GLOBAL_DATA_PTR;
 struct rk_pwm_priv {
 	struct rk3288_pwm *regs;
 	ulong freq;
+	uint enable_conf;
 };
 
+static int rk_pwm_set_invert(struct udevice *dev, uint channel, uint polarity)
+{
+	struct rk_pwm_priv *priv = dev_get_priv(dev);
+
+	debug("%s: polarity=%u\n", __func__, polarity);
+	if (polarity)
+		priv->enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSTIVE;
+	else
+		priv->enable_conf |= PWM_DUTY_POSTIVE | PWM_INACTIVE_NEGATIVE;
+
+	return 0;
+}
+
 static int rk_pwm_set_config(struct udevice *dev, uint channel, uint period_ns,
 			     uint duty_ns)
 {
@@ -32,7 +46,7 @@  static int rk_pwm_set_config(struct udevice *dev, uint channel, uint period_ns,
 
 	debug("%s: period_ns=%u, duty_ns=%u\n", __func__, period_ns, duty_ns);
 	writel(PWM_SEL_SRC_CLK | PWM_OUTPUT_LEFT | PWM_LP_DISABLE |
-		PWM_CONTINUOUS | PWM_DUTY_POSTIVE | PWM_INACTIVE_POSTIVE |
+		PWM_CONTINUOUS | priv->enable_conf |
 		RK_PWM_DISABLE,
 		&regs->ctrl);
 
@@ -83,6 +97,7 @@  static int rk_pwm_probe(struct udevice *dev)
 }
 
 static const struct pwm_ops rk_pwm_ops = {
+	.set_invert	= rk_pwm_set_invert,
 	.set_config	= rk_pwm_set_config,
 	.set_enable	= rk_pwm_set_enable,
 };
diff --git a/include/pwm.h b/include/pwm.h
index 851915e..66c6bf0 100644
--- a/include/pwm.h
+++ b/include/pwm.h
@@ -14,6 +14,15 @@ 
 /* struct pwm_ops: Operations for the PWM uclass */
 struct pwm_ops {
 	/**
+	 * set_invert() - Set the PWM invert
+	 *
+	 * @dev:        PWM device to update
+	 * @channel:    PWM channel to update
+	 * @polarity:  PWM invert polarity
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*set_invert)(struct udevice *dev, uint channel, uint polarity);
+	/**
 	 * set_config() - Set the PWM configuration
 	 *
 	 * @dev:	PWM device to update