[v2,1/2] pwm: fine tune pwm-mtk-disp clock control flow

Commit Message

Jitao Shi Dec. 16, 2019, 7:01 a.m. UTC

Match pwm clock when suspend and resume.
Prepare and enable disp_pwm clock when disp_pwm enable.
Disable and unprepare disp_pwm clock when disp_pwm disable.

Signed-off-by: Jitao Shi <[e-mail]>
---
 drivers/pwm/pwm-mtk-disp.c | 43 +++++++++++---------------------------
 1 file changed, 12 insertions(+), 31 deletions(-)

Comments

Uwe Kleine-König Dec. 16, 2019, 8:18 a.m. UTC | #1

Hello,

On Mon, Dec 16, 2019 at 03:01:22PM +0800, Jitao Shi wrote:
> Match pwm clock when suspend and resume.
> Prepare and enable disp_pwm clock when disp_pwm enable.
> Disable and unprepare disp_pwm clock when disp_pwm disable.

Assuming you catched all clock operations (I didn't check), the patch
looks fine. The commit log could however be improved. Additional to
describing what the patch does, some words about the motivation would be
good. Does this fix a bug? Is it to save some power while the PWM isn't
in use?

Best regards
Uwe

Jitao Shi Dec. 17, 2019, 2:42 a.m. UTC | #2

On Mon, 2019-12-16 at 09:18 +0100, Uwe Kleine-König wrote:
> Hello,
> 
> On Mon, Dec 16, 2019 at 03:01:22PM +0800, Jitao Shi wrote:
> > Match pwm clock when suspend and resume.
> > Prepare and enable disp_pwm clock when disp_pwm enable.
> > Disable and unprepare disp_pwm clock when disp_pwm disable.
> 
> Assuming you catched all clock operations (I didn't check), the patch
> looks fine. The commit log could however be improved. Additional to
> describing what the patch does, some words about the motivation would be
> good. Does this fix a bug? Is it to save some power while the PWM isn't
> in use?
> 
> Best regards
> Uwe
> 

I'll update the commit msg next version.

Thanks for your review.

Best Regards
Jitao

Patch

diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index 83b8be0209b7..c7b14acc9316 100644
--- a/drivers/pwm/pwm-mtk-disp.c
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -98,13 +98,13 @@  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);
+	err = clk_prepare_enable(mdp->clk_main);
 	if (err < 0)
 		return err;
 
-	err = clk_enable(mdp->clk_mm);
+	err = clk_prepare_enable(mdp->clk_mm);
 	if (err < 0) {
-		clk_disable(mdp->clk_main);
+		clk_disable_unprepare(mdp->clk_main);
 		return err;
 	}
 
@@ -124,8 +124,8 @@  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);
+	clk_disable_unprepare(mdp->clk_mm);
+	clk_disable_unprepare(mdp->clk_main);
 
 	return 0;
 }
@@ -135,13 +135,13 @@  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);
+	err = clk_prepare_enable(mdp->clk_main);
 	if (err < 0)
 		return err;
 
-	err = clk_enable(mdp->clk_mm);
+	err = clk_prepare_enable(mdp->clk_mm);
 	if (err < 0) {
-		clk_disable(mdp->clk_main);
+		clk_disable_unprepare(mdp->clk_main);
 		return err;
 	}
 
@@ -158,8 +158,8 @@  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);
+	clk_disable_unprepare(mdp->clk_mm);
+	clk_disable_unprepare(mdp->clk_main);
 }
 
 static const struct pwm_ops mtk_disp_pwm_ops = {
@@ -194,14 +194,6 @@  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.base = -1;
@@ -210,7 +202,7 @@  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);
@@ -229,24 +221,13 @@  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 = {