diff mbox series

[v2,22/66] media: sun6i-csi: Use runtime pm for clocks and reset

Message ID 20220205185429.2278860-23-paul.kocialkowski@bootlin.com (mailing list archive)
State Not Applicable, archived
Headers show
Series Allwinner A31/A83T MIPI CSI-2 Support and A31 ISP Support | expand

Commit Message

Paul Kocialkowski Feb. 5, 2022, 6:53 p.m. UTC 
Wrap the clock and reset preparation into runtime pm functions
for better organization of the code.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
---
 .../platform/sunxi/sun6i-csi/sun6i_csi.c      | 94 ++++++++++++++-----
 1 file changed, 69 insertions(+), 25 deletions(-)

Comments

Maxime Ripard Feb. 9, 2022, 9:22 a.m. UTC | #1 
On Sat, Feb 05, 2022 at 07:53:45PM +0100, Paul Kocialkowski wrote:
> Wrap the clock and reset preparation into runtime pm functions
> for better organization of the code.
> 
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> ---
>  .../platform/sunxi/sun6i-csi/sun6i_csi.c      | 94 ++++++++++++++-----
>  1 file changed, 69 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> index 2355088fdc37..b53b92b70a89 100644
> --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> @@ -152,40 +152,18 @@ int sun6i_csi_set_power(struct sun6i_csi_device *csi_dev, bool enable)
>  
>  	if (!enable) {
>  		regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, 0);
> +		pm_runtime_put(dev);
>  
> -		clk_disable_unprepare(csi_dev->clk_ram);
> -		clk_disable_unprepare(csi_dev->clk_mod);
> -		reset_control_assert(csi_dev->reset);
>  		return 0;
>  	}
>  
> -	ret = clk_prepare_enable(csi_dev->clk_mod);
> -	if (ret) {
> -		dev_err(csi_dev->dev, "Enable csi clk err %d\n", ret);
> +	ret = pm_runtime_resume_and_get(dev);
> +	if (ret < 0)
>  		return ret;
> -	}
> -
> -	ret = clk_prepare_enable(csi_dev->clk_ram);
> -	if (ret) {
> -		dev_err(csi_dev->dev, "Enable clk_dram_csi clk err %d\n", ret);
> -		goto clk_mod_disable;
> -	}
> -
> -	ret = reset_control_deassert(csi_dev->reset);
> -	if (ret) {
> -		dev_err(csi_dev->dev, "reset err %d\n", ret);
> -		goto clk_ram_disable;
> -	}
>  
>  	regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, CSI_EN_CSI_EN);
>  
>  	return 0;
> -
> -clk_ram_disable:
> -	clk_disable_unprepare(csi_dev->clk_ram);
> -clk_mod_disable:
> -	clk_disable_unprepare(csi_dev->clk_mod);
> -	return ret;
>  }
>  
>  static enum csi_input_fmt get_csi_input_format(struct sun6i_csi_device *csi_dev,
> @@ -800,6 +778,65 @@ static irqreturn_t sun6i_csi_isr(int irq, void *private)
>  	return IRQ_HANDLED;
>  }
>  
> +static int sun6i_csi_suspend(struct device *dev)
> +{
> +	struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);
> +
> +	reset_control_assert(csi_dev->reset);
> +	clk_disable_unprepare(csi_dev->clk_ram);
> +	clk_disable_unprepare(csi_dev->clk_mod);
> +	clk_disable_unprepare(csi_dev->clk_bus);
> +
> +	return 0;
> +}
> +
> +static int sun6i_csi_resume(struct device *dev)
> +{
> +	struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);
> +	int ret;
> +
> +	ret = reset_control_deassert(csi_dev->reset);
> +	if (ret) {
> +		dev_err(dev, "failed to deassert reset\n");
> +		return ret;
> +	}
> +
> +	ret = clk_prepare_enable(csi_dev->clk_bus);
> +	if (ret) {
> +		dev_err(dev, "failed to enable bus clock\n");
> +		goto error_reset;
> +	}
> +
> +	ret = clk_prepare_enable(csi_dev->clk_mod);
> +	if (ret) {
> +		dev_err(dev, "failed to enable module clock\n");
> +		goto error_clk_bus;
> +	}
> +
> +	ret = clk_prepare_enable(csi_dev->clk_ram);
> +	if (ret) {
> +		dev_err(dev, "failed to enable ram clock\n");
> +		goto error_clk_mod;
> +	}
> +
> +	return 0;

You've change the order of the reset vs clock initialization. Also, does
that work with CONFIG_PM disabled?

Maxime
Paul Kocialkowski Feb. 11, 2022, 4:01 p.m. UTC | #2 
Hi,

On Wed 09 Feb 22, 10:22, Maxime Ripard wrote:
> On Sat, Feb 05, 2022 at 07:53:45PM +0100, Paul Kocialkowski wrote:
> > Wrap the clock and reset preparation into runtime pm functions
> > for better organization of the code.
> > 
> > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> > ---
> >  .../platform/sunxi/sun6i-csi/sun6i_csi.c      | 94 ++++++++++++++-----
> >  1 file changed, 69 insertions(+), 25 deletions(-)
> > 
> > diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > index 2355088fdc37..b53b92b70a89 100644
> > --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > @@ -152,40 +152,18 @@ int sun6i_csi_set_power(struct sun6i_csi_device *csi_dev, bool enable)
> >  
> >  	if (!enable) {
> >  		regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, 0);
> > +		pm_runtime_put(dev);
> >  
> > -		clk_disable_unprepare(csi_dev->clk_ram);
> > -		clk_disable_unprepare(csi_dev->clk_mod);
> > -		reset_control_assert(csi_dev->reset);
> >  		return 0;
> >  	}
> >  
> > -	ret = clk_prepare_enable(csi_dev->clk_mod);
> > -	if (ret) {
> > -		dev_err(csi_dev->dev, "Enable csi clk err %d\n", ret);
> > +	ret = pm_runtime_resume_and_get(dev);
> > +	if (ret < 0)
> >  		return ret;
> > -	}
> > -
> > -	ret = clk_prepare_enable(csi_dev->clk_ram);
> > -	if (ret) {
> > -		dev_err(csi_dev->dev, "Enable clk_dram_csi clk err %d\n", ret);
> > -		goto clk_mod_disable;
> > -	}
> > -
> > -	ret = reset_control_deassert(csi_dev->reset);
> > -	if (ret) {
> > -		dev_err(csi_dev->dev, "reset err %d\n", ret);
> > -		goto clk_ram_disable;
> > -	}
> >  
> >  	regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, CSI_EN_CSI_EN);
> >  
> >  	return 0;
> > -
> > -clk_ram_disable:
> > -	clk_disable_unprepare(csi_dev->clk_ram);
> > -clk_mod_disable:
> > -	clk_disable_unprepare(csi_dev->clk_mod);
> > -	return ret;
> >  }
> >  
> >  static enum csi_input_fmt get_csi_input_format(struct sun6i_csi_device *csi_dev,
> > @@ -800,6 +778,65 @@ static irqreturn_t sun6i_csi_isr(int irq, void *private)
> >  	return IRQ_HANDLED;
> >  }
> >  
> > +static int sun6i_csi_suspend(struct device *dev)
> > +{
> > +	struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);
> > +
> > +	reset_control_assert(csi_dev->reset);
> > +	clk_disable_unprepare(csi_dev->clk_ram);
> > +	clk_disable_unprepare(csi_dev->clk_mod);
> > +	clk_disable_unprepare(csi_dev->clk_bus);
> > +
> > +	return 0;
> > +}
> > +
> > +static int sun6i_csi_resume(struct device *dev)
> > +{
> > +	struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);
> > +	int ret;
> > +
> > +	ret = reset_control_deassert(csi_dev->reset);
> > +	if (ret) {
> > +		dev_err(dev, "failed to deassert reset\n");
> > +		return ret;
> > +	}
> > +
> > +	ret = clk_prepare_enable(csi_dev->clk_bus);
> > +	if (ret) {
> > +		dev_err(dev, "failed to enable bus clock\n");
> > +		goto error_reset;
> > +	}
> > +
> > +	ret = clk_prepare_enable(csi_dev->clk_mod);
> > +	if (ret) {
> > +		dev_err(dev, "failed to enable module clock\n");
> > +		goto error_clk_bus;
> > +	}
> > +
> > +	ret = clk_prepare_enable(csi_dev->clk_ram);
> > +	if (ret) {
> > +		dev_err(dev, "failed to enable ram clock\n");
> > +		goto error_clk_mod;
> > +	}
> > +
> > +	return 0;
> 
> You've change the order of the reset vs clock initialization.

Oh right. Is there a preference regarding the order?
It probably makes more sense to release reset once all the clocks are
ready rather than the opposite (so that would match the previous order).

> Also, does that work with CONFIG_PM disabled?

It doesn't, but the driver should really depend on PM anyway (it doesn't yet).
That makes me realize that I didn't cleanup the Kconfig entry, which
should have been updated along the way.

Will fix both next time.

Thanks for the review!

Paul
Maxime Ripard Feb. 11, 2022, 4:41 p.m. UTC | #3 
On Fri, Feb 11, 2022 at 05:01:33PM +0100, Paul Kocialkowski wrote:
> On Wed 09 Feb 22, 10:22, Maxime Ripard wrote:
> > On Sat, Feb 05, 2022 at 07:53:45PM +0100, Paul Kocialkowski wrote:
> > > Wrap the clock and reset preparation into runtime pm functions
> > > for better organization of the code.
> > > 
> > > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> > > ---
> > >  .../platform/sunxi/sun6i-csi/sun6i_csi.c      | 94 ++++++++++++++-----
> > >  1 file changed, 69 insertions(+), 25 deletions(-)
> > > 
> > > diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > > index 2355088fdc37..b53b92b70a89 100644
> > > --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > > +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > > @@ -152,40 +152,18 @@ int sun6i_csi_set_power(struct sun6i_csi_device *csi_dev, bool enable)
> > >  
> > >  	if (!enable) {
> > >  		regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, 0);
> > > +		pm_runtime_put(dev);
> > >  
> > > -		clk_disable_unprepare(csi_dev->clk_ram);
> > > -		clk_disable_unprepare(csi_dev->clk_mod);
> > > -		reset_control_assert(csi_dev->reset);
> > >  		return 0;
> > >  	}
> > >  
> > > -	ret = clk_prepare_enable(csi_dev->clk_mod);
> > > -	if (ret) {
> > > -		dev_err(csi_dev->dev, "Enable csi clk err %d\n", ret);
> > > +	ret = pm_runtime_resume_and_get(dev);
> > > +	if (ret < 0)
> > >  		return ret;
> > > -	}
> > > -
> > > -	ret = clk_prepare_enable(csi_dev->clk_ram);
> > > -	if (ret) {
> > > -		dev_err(csi_dev->dev, "Enable clk_dram_csi clk err %d\n", ret);
> > > -		goto clk_mod_disable;
> > > -	}
> > > -
> > > -	ret = reset_control_deassert(csi_dev->reset);
> > > -	if (ret) {
> > > -		dev_err(csi_dev->dev, "reset err %d\n", ret);
> > > -		goto clk_ram_disable;
> > > -	}
> > >  
> > >  	regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, CSI_EN_CSI_EN);
> > >  
> > >  	return 0;
> > > -
> > > -clk_ram_disable:
> > > -	clk_disable_unprepare(csi_dev->clk_ram);
> > > -clk_mod_disable:
> > > -	clk_disable_unprepare(csi_dev->clk_mod);
> > > -	return ret;
> > >  }
> > >  
> > >  static enum csi_input_fmt get_csi_input_format(struct sun6i_csi_device *csi_dev,
> > > @@ -800,6 +778,65 @@ static irqreturn_t sun6i_csi_isr(int irq, void *private)
> > >  	return IRQ_HANDLED;
> > >  }
> > >  
> > > +static int sun6i_csi_suspend(struct device *dev)
> > > +{
> > > +	struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);
> > > +
> > > +	reset_control_assert(csi_dev->reset);
> > > +	clk_disable_unprepare(csi_dev->clk_ram);
> > > +	clk_disable_unprepare(csi_dev->clk_mod);
> > > +	clk_disable_unprepare(csi_dev->clk_bus);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int sun6i_csi_resume(struct device *dev)
> > > +{
> > > +	struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);
> > > +	int ret;
> > > +
> > > +	ret = reset_control_deassert(csi_dev->reset);
> > > +	if (ret) {
> > > +		dev_err(dev, "failed to deassert reset\n");
> > > +		return ret;
> > > +	}
> > > +
> > > +	ret = clk_prepare_enable(csi_dev->clk_bus);
> > > +	if (ret) {
> > > +		dev_err(dev, "failed to enable bus clock\n");
> > > +		goto error_reset;
> > > +	}
> > > +
> > > +	ret = clk_prepare_enable(csi_dev->clk_mod);
> > > +	if (ret) {
> > > +		dev_err(dev, "failed to enable module clock\n");
> > > +		goto error_clk_bus;
> > > +	}
> > > +
> > > +	ret = clk_prepare_enable(csi_dev->clk_ram);
> > > +	if (ret) {
> > > +		dev_err(dev, "failed to enable ram clock\n");
> > > +		goto error_clk_mod;
> > > +	}
> > > +
> > > +	return 0;
> > 
> > You've change the order of the reset vs clock initialization.
> 
> Oh right. Is there a preference regarding the order?
> It probably makes more sense to release reset once all the clocks are
> ready rather than the opposite (so that would match the previous order).

From the datasheet:

4.3.6.4. Gating and reset

Make sure that the reset signal has been released before the release of
module clock gating;

So it looks like the right order. it should still be mentioned in the
commit log.

Maxime
diff mbox series

Patch

diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
index 2355088fdc37..b53b92b70a89 100644
--- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
+++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
@@ -152,40 +152,18 @@  int sun6i_csi_set_power(struct sun6i_csi_device *csi_dev, bool enable)
 
 	if (!enable) {
 		regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, 0);
+		pm_runtime_put(dev);
 
-		clk_disable_unprepare(csi_dev->clk_ram);
-		clk_disable_unprepare(csi_dev->clk_mod);
-		reset_control_assert(csi_dev->reset);
 		return 0;
 	}
 
-	ret = clk_prepare_enable(csi_dev->clk_mod);
-	if (ret) {
-		dev_err(csi_dev->dev, "Enable csi clk err %d\n", ret);
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret < 0)
 		return ret;
-	}
-
-	ret = clk_prepare_enable(csi_dev->clk_ram);
-	if (ret) {
-		dev_err(csi_dev->dev, "Enable clk_dram_csi clk err %d\n", ret);
-		goto clk_mod_disable;
-	}
-
-	ret = reset_control_deassert(csi_dev->reset);
-	if (ret) {
-		dev_err(csi_dev->dev, "reset err %d\n", ret);
-		goto clk_ram_disable;
-	}
 
 	regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, CSI_EN_CSI_EN);
 
 	return 0;
-
-clk_ram_disable:
-	clk_disable_unprepare(csi_dev->clk_ram);
-clk_mod_disable:
-	clk_disable_unprepare(csi_dev->clk_mod);
-	return ret;
 }
 
 static enum csi_input_fmt get_csi_input_format(struct sun6i_csi_device *csi_dev,
@@ -800,6 +778,65 @@  static irqreturn_t sun6i_csi_isr(int irq, void *private)
 	return IRQ_HANDLED;
 }
 
+static int sun6i_csi_suspend(struct device *dev)
+{
+	struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);
+
+	reset_control_assert(csi_dev->reset);
+	clk_disable_unprepare(csi_dev->clk_ram);
+	clk_disable_unprepare(csi_dev->clk_mod);
+	clk_disable_unprepare(csi_dev->clk_bus);
+
+	return 0;
+}
+
+static int sun6i_csi_resume(struct device *dev)
+{
+	struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);
+	int ret;
+
+	ret = reset_control_deassert(csi_dev->reset);
+	if (ret) {
+		dev_err(dev, "failed to deassert reset\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(csi_dev->clk_bus);
+	if (ret) {
+		dev_err(dev, "failed to enable bus clock\n");
+		goto error_reset;
+	}
+
+	ret = clk_prepare_enable(csi_dev->clk_mod);
+	if (ret) {
+		dev_err(dev, "failed to enable module clock\n");
+		goto error_clk_bus;
+	}
+
+	ret = clk_prepare_enable(csi_dev->clk_ram);
+	if (ret) {
+		dev_err(dev, "failed to enable ram clock\n");
+		goto error_clk_mod;
+	}
+
+	return 0;
+
+error_clk_mod:
+	clk_disable_unprepare(csi_dev->clk_mod);
+
+error_clk_bus:
+	clk_disable_unprepare(csi_dev->clk_bus);
+
+error_reset:
+	reset_control_assert(csi_dev->reset);
+
+	return ret;
+}
+
+static const struct dev_pm_ops sun6i_csi_pm_ops = {
+	SET_RUNTIME_PM_OPS(sun6i_csi_suspend, sun6i_csi_resume, NULL)
+};
+
 static const struct regmap_config sun6i_csi_regmap_config = {
 	.reg_bits       = 32,
 	.reg_stride     = 4,
@@ -885,6 +922,11 @@  static int sun6i_csi_resources_setup(struct sun6i_csi_device *csi_dev,
 		goto error_clk_rate_exclusive;
 	}
 
+	/* Runtime PM */
+
+	pm_runtime_enable(dev);
+	pm_runtime_set_suspended(dev);
+
 	return 0;
 
 error_clk_rate_exclusive:
@@ -895,6 +937,7 @@  static int sun6i_csi_resources_setup(struct sun6i_csi_device *csi_dev,
 
 static void sun6i_csi_resources_cleanup(struct sun6i_csi_device *csi_dev)
 {
+	pm_runtime_disable(csi_dev->dev);
 	clk_rate_exclusive_put(csi_dev->clk_mod);
 }
 
@@ -954,6 +997,7 @@  static struct platform_driver sun6i_csi_platform_driver = {
 	.driver	= {
 		.name		= SUN6I_CSI_NAME,
 		.of_match_table	= of_match_ptr(sun6i_csi_of_match),
+		.pm		= &sun6i_csi_pm_ops,
 	},
 };