[PATCH v4 0/3] fix the clock on/off mismatch and switch pwm api to atomic API

[PATCH v4 0/3] fix the clock on/off mismatch and switch pwm api to atomic API

[Jitao Shi]

Change since v3:
 - Seperate the clock sequence as single patch.
 - fixup the reg commit when clocks sequence changed
 - Merege the apply and get_state as single patch

Change since v2:
 - Change commit messages to remove the clock operations for atomic APIs.
 - Rebase to v5.13 rc1

Changes since v1:
 - Seperate clock operation as single patch.
 - Seperate apply() as single patch.
 - Seperate get_state() operation as single patch.

Jitao Shi (3):
  pwm: mtk-disp: adjust the clocks to avoid them mismatch
  pwm: mtk-disp: move the commit to clock enabled
  pwm: mtk-disp: Switch to atomic API

 drivers/pwm/pwm-mtk-disp.c | 167 +++++++++++++++++++++----------------
 1 file changed, 93 insertions(+), 74 deletions(-)

-- 
2.25.1

[PATCH v4 1/3] pwm: mtk-disp: adjust the clocks to avoid them mismatch

[Jitao Shi]

The clk_main and clk_mm clocks are still on when system enter
suspend. That will casue the power consumption.

The clocks call the clk_prepare() in probe(), but the clk_unprepare()
is called in remove(), it isn't called when system suspend.

Remove the clcok opterations from probe() and remove.
Add the clk_prepare_enable() in config().
Add the clk_disable_unprepare() in disable().

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
---
 drivers/pwm/pwm-mtk-disp.c | 81 ++++++++++++++++----------------------
 1 file changed, 33 insertions(+), 48 deletions(-)

diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index 9b3ba401a3db..b5771e2c54b8 100644
--- a/drivers/pwm/pwm-mtk-disp.c
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -47,6 +47,7 @@ struct mtk_disp_pwm {
 	struct clk *clk_main;
 	struct clk *clk_mm;
 	void __iomem *base;
+	bool enabled;
 };
 
 static inline struct mtk_disp_pwm *to_mtk_disp_pwm(struct pwm_chip *chip)
@@ -74,6 +75,22 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	u64 div, rate;
 	int err;
 
+	if (!mdp->enabled) {
+		err = clk_prepare_enable(mdp->clk_main);
+		if (err < 0) {
+			dev_err(chip->dev, "Can't enable mdp->clk_main: %d\n",
+				err);
+			return err;
+		}
+		err = clk_prepare_enable(mdp->clk_mm);
+		if (err < 0) {
+			dev_err(chip->dev, "Can't enable mdp->clk_mm: %d\n",
+				err);
+			clk_disable_unprepare(mdp->clk_main);
+			return err;
+		}
+	}
+
 	/*
 	 * Find period, high_width and clk_div to suit duty_ns and period_ns.
 	 * Calculate proper div value to keep period value in the bound.
@@ -87,9 +104,15 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	rate = clk_get_rate(mdp->clk_main);
 	clk_div = div_u64(rate * period_ns, NSEC_PER_SEC) >>
 			  PWM_PERIOD_BIT_WIDTH;
-	if (clk_div > PWM_CLKDIV_MAX)
+	if (clk_div > PWM_CLKDIV_MAX) {
+		dev_err(chip->dev, "clock rate is too high: rate = %d Hz\n",
+			rate);
+		if (!mdp->enabled) {
+			clk_disable_unprepare(mdp->clk_mm);
+			clk_disable_unprepare(mdp->clk_main);
+		}
 		return -EINVAL;
-
+	}
 	div = NSEC_PER_SEC * (clk_div + 1);
 	period = div64_u64(rate * period_ns, div);
 	if (period > 0)
@@ -98,16 +121,6 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	high_width = div64_u64(rate * duty_ns, div);
 	value = period | (high_width << PWM_HIGH_WIDTH_SHIFT);
 
-	err = clk_enable(mdp->clk_main);
-	if (err < 0)
-		return err;
-
-	err = clk_enable(mdp->clk_mm);
-	if (err < 0) {
-		clk_disable(mdp->clk_main);
-		return err;
-	}
-
 	mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
 				 PWM_CLKDIV_MASK,
 				 clk_div << PWM_CLKDIV_SHIFT);
@@ -124,9 +137,6 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 					 0x0);
 	}
 
-	clk_disable(mdp->clk_mm);
-	clk_disable(mdp->clk_main);
-
 	return 0;
 }
 
@@ -135,18 +145,9 @@ static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
 	int err;
 
-	err = clk_enable(mdp->clk_main);
-	if (err < 0)
-		return err;
-
-	err = clk_enable(mdp->clk_mm);
-	if (err < 0) {
-		clk_disable(mdp->clk_main);
-		return err;
-	}
-
 	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
 				 mdp->data->enable_mask);
+	mdp->enabled = true;
 
 	return 0;
 }
@@ -158,8 +159,11 @@ static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
 				 0x0);
 
-	clk_disable(mdp->clk_mm);
-	clk_disable(mdp->clk_main);
+	if (mdp->enabled) {
+		clk_disable_unprepare(mdp->clk_mm);
+		clk_disable_unprepare(mdp->clk_main);
+	}
+	mdp->enabled = false;
 }
 
 static const struct pwm_ops mtk_disp_pwm_ops = {
@@ -192,14 +196,6 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(mdp->clk_mm))
 		return PTR_ERR(mdp->clk_mm);
 
-	ret = clk_prepare(mdp->clk_main);
-	if (ret < 0)
-		return ret;
-
-	ret = clk_prepare(mdp->clk_mm);
-	if (ret < 0)
-		goto disable_clk_main;
-
 	mdp->chip.dev = &pdev->dev;
 	mdp->chip.ops = &mtk_disp_pwm_ops;
 	mdp->chip.npwm = 1;
@@ -207,7 +203,7 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
 	ret = pwmchip_add(&mdp->chip);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
-		goto disable_clk_mm;
+		return ret;
 	}
 
 	platform_set_drvdata(pdev, mdp);
@@ -226,24 +222,13 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
 	}
 
 	return 0;
-
-disable_clk_mm:
-	clk_unprepare(mdp->clk_mm);
-disable_clk_main:
-	clk_unprepare(mdp->clk_main);
-	return ret;
 }
 
 static int mtk_disp_pwm_remove(struct platform_device *pdev)
 {
 	struct mtk_disp_pwm *mdp = platform_get_drvdata(pdev);
-	int ret;
-
-	ret = pwmchip_remove(&mdp->chip);
-	clk_unprepare(mdp->clk_mm);
-	clk_unprepare(mdp->clk_main);
 
-	return ret;
+	return pwmchip_remove(&mdp->chip);
 }
 
 static const struct mtk_pwm_data mt2701_pwm_data = {
-- 
2.25.1

[PATCH v4 2/3] pwm: mtk-disp: move the commit to clock enabled

[Jitao Shi]

Due to the clock sequence changing, so move the reg commit to
config().

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
---
 drivers/pwm/pwm-mtk-disp.c | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index b5771e2c54b8..b87b3c00a685 100644
--- a/drivers/pwm/pwm-mtk-disp.c
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -135,6 +135,13 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
 					 mdp->data->commit_mask,
 					 0x0);
+	} else {
+		mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug,
+					 mdp->data->bls_debug_mask,
+					 mdp->data->bls_debug_mask);
+		mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
+					 mdp->data->con0_sel,
+					 mdp->data->con0_sel);
 	}
 
 	return 0;
@@ -208,19 +215,6 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, mdp);
 
-	/*
-	 * For MT2701, disable double buffer before writing register
-	 * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH.
-	 */
-	if (!mdp->data->has_commit) {
-		mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug,
-					 mdp->data->bls_debug_mask,
-					 mdp->data->bls_debug_mask);
-		mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
-					 mdp->data->con0_sel,
-					 mdp->data->con0_sel);
-	}
-
 	return 0;
 }
 
-- 
2.25.1

[PATCH v4 3/3] pwm: mtk-disp: Switch to atomic API

[Jitao Shi]

Convert the legacy api to atomic API.

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
---
 drivers/pwm/pwm-mtk-disp.c | 78 ++++++++++++++++++++++++++++----------
 1 file changed, 59 insertions(+), 19 deletions(-)

diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index b87b3c00a685..d77348d0527c 100644
--- a/drivers/pwm/pwm-mtk-disp.c
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -67,8 +67,8 @@ static void mtk_disp_pwm_update_bits(struct mtk_disp_pwm *mdp, u32 offset,
 	writel(value, address);
 }
 
-static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
-			       int duty_ns, int period_ns)
+static int mtk_disp_pwm_config(struct pwm_chip *chip,
+			       const struct pwm_state *state)
 {
 	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
 	u32 clk_div, period, high_width, value;
@@ -102,7 +102,7 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	 * high_width = (PWM_CLK_RATE * duty_ns) / (10^9 * (clk_div + 1))
 	 */
 	rate = clk_get_rate(mdp->clk_main);
-	clk_div = div_u64(rate * period_ns, NSEC_PER_SEC) >>
+	clk_div = div_u64(rate * state->period, NSEC_PER_SEC) >>
 			  PWM_PERIOD_BIT_WIDTH;
 	if (clk_div > PWM_CLKDIV_MAX) {
 		dev_err(chip->dev, "clock rate is too high: rate = %d Hz\n",
@@ -114,11 +114,11 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		return -EINVAL;
 	}
 	div = NSEC_PER_SEC * (clk_div + 1);
-	period = div64_u64(rate * period_ns, div);
+	period = div64_u64(rate * state->period, div);
 	if (period > 0)
 		period--;
 
-	high_width = div64_u64(rate * duty_ns, div);
+	high_width = div64_u64(rate * state->duty_cycle, div);
 	value = period | (high_width << PWM_HIGH_WIDTH_SHIFT);
 
 	mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
@@ -144,39 +144,79 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 					 mdp->data->con0_sel);
 	}
 
+	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
+				 mdp->data->enable_mask);
+	mdp->enabled = true;
+
 	return 0;
 }
 
-static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			      const struct pwm_state *state)
 {
 	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
-	int err;
 
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
-				 mdp->data->enable_mask);
-	mdp->enabled = true;
+	if (!state->enabled) {
+		mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
+					 0x0);
 
-	return 0;
+		if (mdp->enabled) {
+			clk_disable_unprepare(mdp->clk_mm);
+			clk_disable_unprepare(mdp->clk_main);
+		}
+		mdp->enabled = false;
+		return 0;
+	}
+
+	return mtk_disp_pwm_config(chip, state);
 }
 
-static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+static void mtk_disp_pwm_get_state(struct pwm_chip *chip,
+				   struct pwm_device *pwm,
+				   struct pwm_state *state)
 {
 	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
+	u32 clk_div, period, high_width, con0, con1;
+	u64 rate;
+	int err;
 
-	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
-				 0x0);
+	if (!mdp->enabled) {
+		err = clk_prepare_enable(mdp->clk_main);
+		if (err < 0) {
+			dev_err(chip->dev, "Can't enable mdp->clk_main: %d\n", err);
+			return;
+		}
+		err = clk_prepare_enable(mdp->clk_mm);
+		if (err < 0) {
+			dev_err(chip->dev, "Can't enable mdp->clk_mm: %d\n", err);
+			clk_disable_unprepare(mdp->clk_main);
+			return;
+		}
+	}
+
+	rate = clk_get_rate(mdp->clk_main);
 
-	if (mdp->enabled) {
+	con0 = readl(mdp->base + mdp->data->con0);
+	con1 = readl(mdp->base + mdp->data->con1);
+
+	state->enabled = !!(con0 & BIT(0));
+
+	clk_div = (con0 & PWM_CLKDIV_MASK) >> PWM_CLKDIV_SHIFT;
+	period = con1 & PWM_PERIOD_MASK;
+	state->period = div_u64(period * (clk_div + 1) * NSEC_PER_SEC, rate);
+	high_width = (con1 & PWM_HIGH_WIDTH_MASK) >> PWM_HIGH_WIDTH_SHIFT;
+	state->duty_cycle = div_u64(high_width * (clk_div + 1) * NSEC_PER_SEC,
+				    rate);
+
+	if (!mdp->enabled) {
 		clk_disable_unprepare(mdp->clk_mm);
 		clk_disable_unprepare(mdp->clk_main);
 	}
-	mdp->enabled = false;
 }
 
 static const struct pwm_ops mtk_disp_pwm_ops = {
-	.config = mtk_disp_pwm_config,
-	.enable = mtk_disp_pwm_enable,
-	.disable = mtk_disp_pwm_disable,
+	.apply = mtk_disp_pwm_apply,
+	.get_state = mtk_disp_pwm_get_state,
 	.owner = THIS_MODULE,
 };
 
-- 
2.25.1

Re: [PATCH v4 1/3] pwm: mtk-disp: adjust the clocks to avoid them mismatch

[Uwe Kleine-König]

[-- Attachment #1: Type: text/plain, Size: 3919 bytes --]

Hello,

you missed to address Lee and me for your patch series. I just happend
to stumble over this series by a fluke.

On Thu, Jun 03, 2021 at 06:05:29PM +0800, Jitao Shi wrote:
> The clk_main and clk_mm clocks are still on when system enter
> suspend. That will casue the power consumption.
> 
> The clocks call the clk_prepare() in probe(), but the clk_unprepare()
> is called in remove(), it isn't called when system suspend.

The English could be improved here. Something like:

	The clks "main" and "mm" are prepared in .probe() (and
	unprepared in .remove()). This results in the clocks being on
	during suspend which results in unnecessarily increased power
	consumption.

> Remove the clcok opterations from probe() and remove.

s/clcok/clock/, s/e\./e()/

> Add the clk_prepare_enable() in config().
> Add the clk_disable_unprepare() in disable().
> 
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> ---
>  drivers/pwm/pwm-mtk-disp.c | 81 ++++++++++++++++----------------------
>  1 file changed, 33 insertions(+), 48 deletions(-)
> 
> diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
> index 9b3ba401a3db..b5771e2c54b8 100644
> --- a/drivers/pwm/pwm-mtk-disp.c
> +++ b/drivers/pwm/pwm-mtk-disp.c
> @@ -47,6 +47,7 @@ struct mtk_disp_pwm {
>  	struct clk *clk_main;
>  	struct clk *clk_mm;
>  	void __iomem *base;
> +	bool enabled;
>  };
>  
>  static inline struct mtk_disp_pwm *to_mtk_disp_pwm(struct pwm_chip *chip)
> @@ -74,6 +75,22 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>  	u64 div, rate;
>  	int err;
>  
> +	if (!mdp->enabled) {
> +		err = clk_prepare_enable(mdp->clk_main);
> +		if (err < 0) {
> +			dev_err(chip->dev, "Can't enable mdp->clk_main: %d\n",
> +				err);
> +			return err;

Please use %pe to get symbolic error names which are better
understandable.

> +		}
> +		err = clk_prepare_enable(mdp->clk_mm);
> +		if (err < 0) {
> +			dev_err(chip->dev, "Can't enable mdp->clk_mm: %d\n",
> +				err);
> +			clk_disable_unprepare(mdp->clk_main);
> +			return err;
> +		}
> +	}
> +
>  	/*
>  	 * Find period, high_width and clk_div to suit duty_ns and period_ns.
>  	 * Calculate proper div value to keep period value in the bound.
> @@ -87,9 +104,15 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>  	rate = clk_get_rate(mdp->clk_main);
>  	clk_div = div_u64(rate * period_ns, NSEC_PER_SEC) >>
>  			  PWM_PERIOD_BIT_WIDTH;
> -	if (clk_div > PWM_CLKDIV_MAX)
> +	if (clk_div > PWM_CLKDIV_MAX) {
> +		dev_err(chip->dev, "clock rate is too high: rate = %d Hz\n",
> +			rate);

Adding an error message here is orthogonal to this patch. Either drop it
or mention it in the commit log please.

> +		if (!mdp->enabled) {
> +			clk_disable_unprepare(mdp->clk_mm);
> +			clk_disable_unprepare(mdp->clk_main);
> +		}
>  		return -EINVAL;
> -
> +	}
>  	div = NSEC_PER_SEC * (clk_div + 1);
>  	period = div64_u64(rate * period_ns, div);
>  	if (period > 0)
> [...]
> @@ -135,18 +145,9 @@ static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
>  	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
>  	int err;
>  
> -	err = clk_enable(mdp->clk_main);
> -	if (err < 0)
> -		return err;
> -
> -	err = clk_enable(mdp->clk_mm);
> -	if (err < 0) {
> -		clk_disable(mdp->clk_main);
> -		return err;
> -	}
> -
>  	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
>  				 mdp->data->enable_mask);
> +	mdp->enabled = true;

The modification to .enable() looks wrong. After the PWM was disabled
the clocks are off, so .enable() must reenable them, doesn't it?

>  	return 0;
>  }

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: [PATCH v4 2/3] pwm: mtk-disp: move the commit to clock enabled

[Uwe Kleine-König]

[-- Attachment #1: Type: text/plain, Size: 2051 bytes --]

On Thu, Jun 03, 2021 at 06:05:30PM +0800, Jitao Shi wrote:
> Due to the clock sequence changing, so move the reg commit to

Which change do you refer to, here? The previous patch? If so, I assume
this means the series is not bisectable because the driver is broken
when only the first patch is applied?

> config().
> 
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> ---
>  drivers/pwm/pwm-mtk-disp.c | 20 +++++++-------------
>  1 file changed, 7 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
> index b5771e2c54b8..b87b3c00a685 100644
> --- a/drivers/pwm/pwm-mtk-disp.c
> +++ b/drivers/pwm/pwm-mtk-disp.c
> @@ -135,6 +135,13 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>  		mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
>  					 mdp->data->commit_mask,
>  					 0x0);
> +	} else {

You dropped the code comment? Is it wrong? Or is it too obvious to be
mentioned?

> +		mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug,
> +					 mdp->data->bls_debug_mask,
> +					 mdp->data->bls_debug_mask);
> +		mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
> +					 mdp->data->con0_sel,
> +					 mdp->data->con0_sel);
>  	}
>  
>  	return 0;
> @@ -208,19 +215,6 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, mdp);
>  
> -	/*
> -	 * For MT2701, disable double buffer before writing register
> -	 * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH.
> -	 */
> -	if (!mdp->data->has_commit) {
> -		mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug,
> -					 mdp->data->bls_debug_mask,
> -					 mdp->data->bls_debug_mask);
> -		mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
> -					 mdp->data->con0_sel,
> -					 mdp->data->con0_sel);
> -	}
> -
>  	return 0;
>  }

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: [PATCH v4 3/3] pwm: mtk-disp: Switch to atomic API

[Uwe Kleine-König]

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Hello,

On Thu, Jun 03, 2021 at 06:05:31PM +0800, Jitao Shi wrote:
> Convert the legacy api to atomic API.
> 
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> ---
>  drivers/pwm/pwm-mtk-disp.c | 78 ++++++++++++++++++++++++++++----------
>  1 file changed, 59 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
> index b87b3c00a685..d77348d0527c 100644
> --- a/drivers/pwm/pwm-mtk-disp.c
> +++ b/drivers/pwm/pwm-mtk-disp.c
> @@ -67,8 +67,8 @@ static void mtk_disp_pwm_update_bits(struct mtk_disp_pwm *mdp, u32 offset,
>  	writel(value, address);
>  }
>  
> -static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
> -			       int duty_ns, int period_ns)
> +static int mtk_disp_pwm_config(struct pwm_chip *chip,
> +			       const struct pwm_state *state)
>  {
>  	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
>  	u32 clk_div, period, high_width, value;
> @@ -102,7 +102,7 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>  	 * high_width = (PWM_CLK_RATE * duty_ns) / (10^9 * (clk_div + 1))
>  	 */
>  	rate = clk_get_rate(mdp->clk_main);
> -	clk_div = div_u64(rate * period_ns, NSEC_PER_SEC) >>
> +	clk_div = div_u64(rate * state->period, NSEC_PER_SEC) >>
>  			  PWM_PERIOD_BIT_WIDTH;
>  	if (clk_div > PWM_CLKDIV_MAX) {
>  		dev_err(chip->dev, "clock rate is too high: rate = %d Hz\n",
> @@ -114,11 +114,11 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>  		return -EINVAL;
>  	}
>  	div = NSEC_PER_SEC * (clk_div + 1);
> -	period = div64_u64(rate * period_ns, div);
> +	period = div64_u64(rate * state->period, div);
>  	if (period > 0)
>  		period--;
>  
> -	high_width = div64_u64(rate * duty_ns, div);
> +	high_width = div64_u64(rate * state->duty_cycle, div);
>  	value = period | (high_width << PWM_HIGH_WIDTH_SHIFT);
>  
>  	mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
> @@ -144,39 +144,79 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>  					 mdp->data->con0_sel);
>  	}
>  
> +	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
> +				 mdp->data->enable_mask);
> +	mdp->enabled = true;
> +
>  	return 0;
>  }
>  
> -static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
> +static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> +			      const struct pwm_state *state)
>  {
>  	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
> -	int err;
>  
> -	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
> -				 mdp->data->enable_mask);
> -	mdp->enabled = true;
> +	if (!state->enabled) {
> +		mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
> +					 0x0);
>  
> -	return 0;
> +		if (mdp->enabled) {
> +			clk_disable_unprepare(mdp->clk_mm);
> +			clk_disable_unprepare(mdp->clk_main);
> +		}
> +		mdp->enabled = false;
> +		return 0;
> +	}
> +
> +	return mtk_disp_pwm_config(chip, state);

Please unroll this function call. Having the old name is irritating.

>  }
>  
> -static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
> +static void mtk_disp_pwm_get_state(struct pwm_chip *chip,
> +				   struct pwm_device *pwm,
> +				   struct pwm_state *state)

Adding .get_state() is great and warrants a separate patch.

>  {
>  	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
> +	u32 clk_div, period, high_width, con0, con1;
> +	u64 rate;
> +	int err;
>  
> -	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
> -				 0x0);
> +	if (!mdp->enabled) {
> +		err = clk_prepare_enable(mdp->clk_main);
> +		if (err < 0) {
> +			dev_err(chip->dev, "Can't enable mdp->clk_main: %d\n", err);
> +			return;
> +		}
> +		err = clk_prepare_enable(mdp->clk_mm);
> +		if (err < 0) {
> +			dev_err(chip->dev, "Can't enable mdp->clk_mm: %d\n", err);
> +			clk_disable_unprepare(mdp->clk_main);
> +			return;
> +		}
> +	}
> +
> +	rate = clk_get_rate(mdp->clk_main);
>  
> -	if (mdp->enabled) {
> +	con0 = readl(mdp->base + mdp->data->con0);
> +	con1 = readl(mdp->base + mdp->data->con1);
> +
> +	state->enabled = !!(con0 & BIT(0));
> +
> +	clk_div = (con0 & PWM_CLKDIV_MASK) >> PWM_CLKDIV_SHIFT;

clk_div = FIELD_GET(PWM_CLKDIV_MASK, con0);

> +	period = con1 & PWM_PERIOD_MASK;
> +	state->period = div_u64(period * (clk_div + 1) * NSEC_PER_SEC, rate);

Can this multiplication overflow? Note this is a 32bit multiplication
only. As .apply() uses round-down in the divisions (which is good)
please round up there to get idempotency between .get_state() and
.apply().

> +	high_width = (con1 & PWM_HIGH_WIDTH_MASK) >> PWM_HIGH_WIDTH_SHIFT;
> +	state->duty_cycle = div_u64(high_width * (clk_div + 1) * NSEC_PER_SEC,
> +				    rate);
> +
> +	if (!mdp->enabled) {
>  		clk_disable_unprepare(mdp->clk_mm);
>  		clk_disable_unprepare(mdp->clk_main);
>  	}
> -	mdp->enabled = false;
>  }

If my review comments contain too little details for you to understand,
please feel free to ask. I'm willing to explain in more detail.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: [PATCH v4 2/3] pwm: mtk-disp: move the commit to clock enabled

[Jitao Shi]

On Sun, 2021-06-06 at 23:14 +0200, Uwe Kleine-König wrote:
> On Thu, Jun 03, 2021 at 06:05:30PM +0800, Jitao Shi wrote:
> > Due to the clock sequence changing, so move the reg commit to
> 
> Which change do you refer to, here? The previous patch? If so, I assume
> this means the series is not bisectable because the driver is broken
> when only the first patch is applied?
> 
Yes, this patch is depend the previous patch.
I'll squash it to the previous patch in next version.


> > config().
> > 
> > Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> > ---
> >  drivers/pwm/pwm-mtk-disp.c | 20 +++++++-------------
> >  1 file changed, 7 insertions(+), 13 deletions(-)
> > 
> > diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
> > index b5771e2c54b8..b87b3c00a685 100644
> > --- a/drivers/pwm/pwm-mtk-disp.c
> > +++ b/drivers/pwm/pwm-mtk-disp.c
> > @@ -135,6 +135,13 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
> >  		mtk_disp_pwm_update_bits(mdp, mdp->data->commit,
> >  					 mdp->data->commit_mask,
> >  					 0x0);
> > +	} else {
> 
> You dropped the code comment? Is it wrong? Or is it too obvious to be
> mentioned?
> 

I'll fix them next verison.

> > +		mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug,
> > +					 mdp->data->bls_debug_mask,
> > +					 mdp->data->bls_debug_mask);
> > +		mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
> > +					 mdp->data->con0_sel,
> > +					 mdp->data->con0_sel);
> >  	}
> >  
> >  	return 0;
> > @@ -208,19 +215,6 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
> >  
> >  	platform_set_drvdata(pdev, mdp);
> >  
> > -	/*
> > -	 * For MT2701, disable double buffer before writing register
> > -	 * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH.
> > -	 */
> > -	if (!mdp->data->has_commit) {
> > -		mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug,
> > -					 mdp->data->bls_debug_mask,
> > -					 mdp->data->bls_debug_mask);
> > -		mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
> > -					 mdp->data->con0_sel,
> > -					 mdp->data->con0_sel);
> > -	}
> > -
> >  	return 0;
> >  }
> 
> Best regards
> Uwe
> 

Best Regards
Jitao

Re: [PATCH v4 3/3] pwm: mtk-disp: Switch to atomic API

[Jitao Shi]

On Sun, 2021-06-06 at 23:22 +0200, Uwe Kleine-König wrote:
> Hello,
> 
> On Thu, Jun 03, 2021 at 06:05:31PM +0800, Jitao Shi wrote:
> > Convert the legacy api to atomic API.
> > 
> > Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> > ---
> >  drivers/pwm/pwm-mtk-disp.c | 78 ++++++++++++++++++++++++++++----------
> >  1 file changed, 59 insertions(+), 19 deletions(-)
> > 
> > diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
> > index b87b3c00a685..d77348d0527c 100644
> > --- a/drivers/pwm/pwm-mtk-disp.c
> > +++ b/drivers/pwm/pwm-mtk-disp.c
> > @@ -67,8 +67,8 @@ static void mtk_disp_pwm_update_bits(struct mtk_disp_pwm *mdp, u32 offset,
> >  	writel(value, address);
> >  }
> >  
> > -static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
> > -			       int duty_ns, int period_ns)
> > +static int mtk_disp_pwm_config(struct pwm_chip *chip,
> > +			       const struct pwm_state *state)
> >  {
> >  	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
> >  	u32 clk_div, period, high_width, value;
> > @@ -102,7 +102,7 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
> >  	 * high_width = (PWM_CLK_RATE * duty_ns) / (10^9 * (clk_div + 1))
> >  	 */
> >  	rate = clk_get_rate(mdp->clk_main);
> > -	clk_div = div_u64(rate * period_ns, NSEC_PER_SEC) >>
> > +	clk_div = div_u64(rate * state->period, NSEC_PER_SEC) >>
> >  			  PWM_PERIOD_BIT_WIDTH;
> >  	if (clk_div > PWM_CLKDIV_MAX) {
> >  		dev_err(chip->dev, "clock rate is too high: rate = %d Hz\n",
> > @@ -114,11 +114,11 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
> >  		return -EINVAL;
> >  	}
> >  	div = NSEC_PER_SEC * (clk_div + 1);
> > -	period = div64_u64(rate * period_ns, div);
> > +	period = div64_u64(rate * state->period, div);
> >  	if (period > 0)
> >  		period--;
> >  
> > -	high_width = div64_u64(rate * duty_ns, div);
> > +	high_width = div64_u64(rate * state->duty_cycle, div);
> >  	value = period | (high_width << PWM_HIGH_WIDTH_SHIFT);
> >  
> >  	mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
> > @@ -144,39 +144,79 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
> >  					 mdp->data->con0_sel);
> >  	}
> >  
> > +	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
> > +				 mdp->data->enable_mask);
> > +	mdp->enabled = true;
> > +
> >  	return 0;
> >  }
> >  
> > -static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
> > +static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> > +			      const struct pwm_state *state)
> >  {
> >  	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
> > -	int err;
> >  
> > -	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
> > -				 mdp->data->enable_mask);
> > -	mdp->enabled = true;
> > +	if (!state->enabled) {
> > +		mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
> > +					 0x0);
> >  
> > -	return 0;
> > +		if (mdp->enabled) {
> > +			clk_disable_unprepare(mdp->clk_mm);
> > +			clk_disable_unprepare(mdp->clk_main);
> > +		}
> > +		mdp->enabled = false;
> > +		return 0;
> > +	}
> > +
> > +	return mtk_disp_pwm_config(chip, state);
> 
> Please unroll this function call. Having the old name is irritating.

I'll fix it next version.

Thanks for your review.
> 
> >  }
> >  
> > -static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
> > +static void mtk_disp_pwm_get_state(struct pwm_chip *chip,
> > +				   struct pwm_device *pwm,
> > +				   struct pwm_state *state)
> 
> Adding .get_state() is great and warrants a separate patch.
> 
I'll separate .get_state() next version.

Thanks for your review.

> >  {
> >  	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
> > +	u32 clk_div, period, high_width, con0, con1;
> > +	u64 rate;
> > +	int err;
> >  
> > -	mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
> > -				 0x0);
> > +	if (!mdp->enabled) {
> > +		err = clk_prepare_enable(mdp->clk_main);
> > +		if (err < 0) {
> > +			dev_err(chip->dev, "Can't enable mdp->clk_main: %d\n", err);
> > +			return;
> > +		}
> > +		err = clk_prepare_enable(mdp->clk_mm);
> > +		if (err < 0) {
> > +			dev_err(chip->dev, "Can't enable mdp->clk_mm: %d\n", err);
> > +			clk_disable_unprepare(mdp->clk_main);
> > +			return;
> > +		}
> > +	}
> > +
> > +	rate = clk_get_rate(mdp->clk_main);
> >  
> > -	if (mdp->enabled) {
> > +	con0 = readl(mdp->base + mdp->data->con0);
> > +	con1 = readl(mdp->base + mdp->data->con1);
> > +
> > +	state->enabled = !!(con0 & BIT(0));
> > +
> > +	clk_div = (con0 & PWM_CLKDIV_MASK) >> PWM_CLKDIV_SHIFT;
> 
> clk_div = FIELD_GET(PWM_CLKDIV_MASK, con0);

I'll fix it next version.


> 
> > +	period = con1 & PWM_PERIOD_MASK;
> > +	state->period = div_u64(period * (clk_div + 1) * NSEC_PER_SEC, rate);
> 
> Can this multiplication overflow? Note this is a 32bit multiplication
> only. As .apply() uses round-down in the divisions (which is good)
> please round up there to get idempotency between .get_state() and
> .apply().
> 

I'll fix it next version.


> > +	high_width = (con1 & PWM_HIGH_WIDTH_MASK) >> PWM_HIGH_WIDTH_SHIFT;
> > +	state->duty_cycle = div_u64(high_width * (clk_div + 1) * NSEC_PER_SEC,
> > +				    rate);
> > +
> > +	if (!mdp->enabled) {
> >  		clk_disable_unprepare(mdp->clk_mm);
> >  		clk_disable_unprepare(mdp->clk_main);
> >  	}
> > -	mdp->enabled = false;
> >  }
> 
> If my review comments contain too little details for you to understand,
> please feel free to ask. I'm willing to explain in more detail.
> 
> Best regards
> Uwe
> 

Thanks for your review.

Best Regards
Jitao