diff mbox

[RFC,13/15] pwm: rockchip: add support for atomic update

Message ID 1435738921-25027-14-git-send-email-boris.brezillon@free-electrons.com (mailing list archive)
State New, archived
Headers show

Commit Message

Boris BREZILLON July 1, 2015, 8:21 a.m. UTC 
Implement the ->apply() function to add support for atomic update.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
 drivers/pwm/pwm-rockchip.c | 75 ++++++++++++++++++++++++++++++----------------
 1 file changed, 49 insertions(+), 26 deletions(-)

Comments

Heiko Stuebner July 1, 2015, 9:48 p.m. UTC | #1 
Hi Boris,


Am Mittwoch, 1. Juli 2015, 10:21:59 schrieb Boris Brezillon:
> Implement the ->apply() function to add support for atomic update.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> ---
> @@ -110,6 +113,26 @@ static void rockchip_pwm_set_enable_v2(struct pwm_chip
> *chip, writel_relaxed(val, pc->base + pc->data->regs.ctrl);
>  }
> 
> +static void rockchip_pwm_init_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;
> +
> +	enable_conf = PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
> +
> +	if ((val & enable_conf) == enable_conf)
> +		pwm->state.polarity = PWM_POLARITY_INVERSED;

the inactive setting does not affect the polarity of the running pwm, only what 
to do when it gets turned off. Also PWM_DUTY_NEGATIVE is the "0" value for the 
bit so also is bad to compare against (and results in wrong readings). So I 
would suggest changing this like

-       enable_conf = PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
+       enable_conf = PWM_DUTY_POSITIVE;
 
-       if ((val & enable_conf) == enable_conf)
+       if ((val & enable_conf) != enable_conf)
 

> +}
> +
>  static void rockchip_pwm_init_state(struct pwm_chip *chip,
>  				    struct pwm_device *pwm)
>  {


Heiko
--
To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Boris BREZILLON July 2, 2015, 7:43 a.m. UTC | #2 
Hi Heiko,

On Wed, 01 Jul 2015 23:48:31 +0200
Heiko Stübner <heiko@sntech.de> wrote:

> Hi Boris,
> 
> 
> Am Mittwoch, 1. Juli 2015, 10:21:59 schrieb Boris Brezillon:
> > Implement the ->apply() function to add support for atomic update.
> > 
> > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> > ---
> > @@ -110,6 +113,26 @@ static void rockchip_pwm_set_enable_v2(struct pwm_chip
> > *chip, writel_relaxed(val, pc->base + pc->data->regs.ctrl);
> >  }
> > 
> > +static void rockchip_pwm_init_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;
> > +
> > +	enable_conf = PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
> > +
> > +	if ((val & enable_conf) == enable_conf)
> > +		pwm->state.polarity = PWM_POLARITY_INVERSED;
> 
> the inactive setting does not affect the polarity of the running pwm, only what 
> to do when it gets turned off. Also PWM_DUTY_NEGATIVE is the "0" value for the 
> bit so also is bad to compare against (and results in wrong readings). So I 
> would suggest changing this like

Indeed

> 
> -       enable_conf = PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
> +       enable_conf = PWM_DUTY_POSITIVE;
>  
> -       if ((val & enable_conf) == enable_conf)
> +       if ((val & enable_conf) != enable_conf)

Or just:

	if(val & PWM_DUTY_POSITIVE)


Thanks for the fix.

Best Regards,

Boris
diff mbox

Patch

diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
index 11e932d..cbe619bf 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 (*init)(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;
@@ -88,14 +90,15 @@  static void rockchip_pwm_init_v1(struct pwm_chip *chip, struct pwm_device *pwm)
 }
 
 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;
@@ -110,6 +113,26 @@  static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
 	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
 }
 
+static void rockchip_pwm_init_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;
+
+	enable_conf = PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
+
+	if ((val & enable_conf) == enable_conf)
+		pwm->state.polarity = PWM_POLARITY_INVERSED;
+}
+
 static void rockchip_pwm_init_state(struct pwm_chip *chip,
 				    struct pwm_device *pwm)
 {
@@ -146,7 +169,6 @@  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);
 
@@ -163,15 +185,8 @@  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;
 }
@@ -189,43 +204,51 @@  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 = {
 	.init_state = rockchip_pwm_init_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 = {
 	.init_state = rockchip_pwm_init_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,
 };