[PATCH v2 0/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm

[PATCH v2 0/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm

[Guido Günther]

This allows us to shut down the mipi power domain on the imx8. The alternative
would be to drop the dphy from the mipi power domain in the SOCs device tree
and only have the DSI host controller visible there but since the PD is mostly
about the PHY that would defeat it's purpose.

This is basically a resend from February 2020 which went without feedback.

This allows to shut off the power domain hen blanking the LCD panel:

pm_genpd_summary before:

domain                          status          slaves
    /device                                             runtime status
----------------------------------------------------------------------
mipi                            on
    /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  unsupported
    /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended

after:

mipi                            off-0
    /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  suspended
    /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended

Changes from v1:
 - Tweak commit message slightly

Guido Günther (1):
  phy: fsl-imx8-mipi-dphy: Hook into runtime pm

 .../phy/freescale/phy-fsl-imx8-mipi-dphy.c    | 22 ++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

-- 
2.29.2


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[PATCH v2 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm

[Guido Günther]

This allows us to shut down the mipi power domain on the imx8. The
alternative would be to drop the dphy from the mipi power domain in the
SOCs device tree and only have the DSI host controller visible there but
since the PD is mostly about the PHY that would defeat it's purpose.

This allows to shut off the power domain hen blanking the LCD panel:

pm_genpd_summary before:

domain                          status          slaves
    /device                                             runtime status
----------------------------------------------------------------------
mipi                            on
    /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  unsupported
    /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended

after:

mipi                            off-0
    /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  suspended
    /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended

Signed-off-by: Guido Günther <agx@sigxcpu.org>
---
 .../phy/freescale/phy-fsl-imx8-mipi-dphy.c    | 22 ++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
index a95572b397ca..34e2d801e520 100644
--- a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
+++ b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
@@ -14,6 +14,7 @@
 #include <linux/of_platform.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 
 /* DPHY registers */
@@ -93,6 +94,7 @@ struct mixel_dphy_cfg {
 };
 
 struct mixel_dphy_priv {
+	struct device *dev;
 	struct mixel_dphy_cfg cfg;
 	struct regmap *regmap;
 	struct clk *phy_ref_clk;
@@ -382,6 +384,7 @@ static int mixel_dphy_power_on(struct phy *phy)
 	ret = clk_prepare_enable(priv->phy_ref_clk);
 	if (ret < 0)
 		return ret;
+	pm_runtime_get_sync(priv->dev);
 
 	phy_write(phy, PWR_ON, DPHY_PD_PLL);
 	ret = regmap_read_poll_timeout(priv->regmap, DPHY_LOCK, locked,
@@ -395,6 +398,7 @@ static int mixel_dphy_power_on(struct phy *phy)
 
 	return 0;
 clock_disable:
+	pm_runtime_put(priv->dev);
 	clk_disable_unprepare(priv->phy_ref_clk);
 	return ret;
 }
@@ -406,6 +410,7 @@ static int mixel_dphy_power_off(struct phy *phy)
 	phy_write(phy, PWR_OFF, DPHY_PD_PLL);
 	phy_write(phy, PWR_OFF, DPHY_PD_DPHY);
 
+	pm_runtime_put(priv->dev);
 	clk_disable_unprepare(priv->phy_ref_clk);
 
 	return 0;
@@ -467,6 +472,7 @@ static int mixel_dphy_probe(struct platform_device *pdev)
 	dev_dbg(dev, "phy_ref clock rate: %lu\n",
 		clk_get_rate(priv->phy_ref_clk));
 
+	priv->dev = dev;
 	dev_set_drvdata(dev, priv);
 
 	phy = devm_phy_create(dev, np, &mixel_dphy_phy_ops);
@@ -477,12 +483,26 @@ static int mixel_dphy_probe(struct platform_device *pdev)
 	phy_set_drvdata(phy, priv);
 
 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+	if (IS_ERR(phy_provider))
+		return PTR_ERR(phy_provider);
 
-	return PTR_ERR_OR_ZERO(phy_provider);
+	pm_runtime_enable(dev);
+
+	return 0;
+}
+
+static int mixel_dphy_remove(struct platform_device *pdev)
+{
+	struct mixel_dphy_priv *priv = platform_get_drvdata(pdev);
+
+	pm_runtime_disable(priv->dev);
+
+	return 0;
 }
 
 static struct platform_driver mixel_dphy_driver = {
 	.probe	= mixel_dphy_probe,
+	.remove = mixel_dphy_remove,
 	.driver = {
 		.name = "mixel-mipi-dphy",
 		.of_match_table	= mixel_dphy_of_match,
-- 
2.29.2


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Re: [PATCH v2 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm

[Lucas Stach]

Hi Guido,

Am Mittwoch, dem 16.12.2020 um 12:27 +0100 schrieb Guido Günther:
This allows us to shut down the mipi power domain on the imx8. The
alternative would be to drop the dphy from the mipi power domain in the
SOCs device tree and only have the DSI host controller visible there but
since the PD is mostly about the PHY that would defeat it's purpose.

Adding RPM support is exactly the right course of action.

This allows to shut off the power domain hen blanking the LCD panel:

pm_genpd_summary before:

domain                          status          slaves
    /device                                             runtime status
----------------------------------------------------------------------
mipi                            on
    /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  unsupported
    /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended

after:

mipi                            off-0
    /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  suspended
    /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended

Signed-off-by: Guido Günther <agx@sigxcpu.org>
---
 .../phy/freescale/phy-fsl-imx8-mipi-dphy.c    | 22 ++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
index a95572b397ca..34e2d801e520 100644
--- a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
+++ b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
@@ -14,6 +14,7 @@
 #include <linux/of_platform.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 

 /* DPHY registers */
@@ -93,6 +94,7 @@ struct mixel_dphy_cfg {
 };
 

 struct mixel_dphy_priv {
+	struct device *dev;
 	struct mixel_dphy_cfg cfg;
 	struct regmap *regmap;
 	struct clk *phy_ref_clk;
@@ -382,6 +384,7 @@ static int mixel_dphy_power_on(struct phy *phy)
 	ret = clk_prepare_enable(priv->phy_ref_clk);
 	if (ret < 0)
 		return ret;
+	pm_runtime_get_sync(priv->dev);

This call can fail and will leave you with an elevated rpm refcount.
Better use the new pm_runtime_resume_and_get to avoid this issue? 

Nitpick: I would add a blank line before the call.

Regards,
Lucas

 

 	phy_write(phy, PWR_ON, DPHY_PD_PLL);
 	ret = regmap_read_poll_timeout(priv->regmap, DPHY_LOCK, locked,
@@ -395,6 +398,7 @@ static int mixel_dphy_power_on(struct phy *phy)
 

 	return 0;
 clock_disable:
+	pm_runtime_put(priv->dev);
 	clk_disable_unprepare(priv->phy_ref_clk);
 	return ret;
 }
@@ -406,6 +410,7 @@ static int mixel_dphy_power_off(struct phy *phy)
 	phy_write(phy, PWR_OFF, DPHY_PD_PLL);
 	phy_write(phy, PWR_OFF, DPHY_PD_DPHY);
 

+	pm_runtime_put(priv->dev);
 	clk_disable_unprepare(priv->phy_ref_clk);
 

 	return 0;
@@ -467,6 +472,7 @@ static int mixel_dphy_probe(struct platform_device *pdev)
 	dev_dbg(dev, "phy_ref clock rate: %lu\n",
 		clk_get_rate(priv->phy_ref_clk));
 

+	priv->dev = dev;
 	dev_set_drvdata(dev, priv);
 

 	phy = devm_phy_create(dev, np, &mixel_dphy_phy_ops);
@@ -477,12 +483,26 @@ static int mixel_dphy_probe(struct platform_device *pdev)
 	phy_set_drvdata(phy, priv);
 

 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+	if (IS_ERR(phy_provider))
+		return PTR_ERR(phy_provider);
 

-	return PTR_ERR_OR_ZERO(phy_provider);
+	pm_runtime_enable(dev);
+
+	return 0;
+}
+
+static int mixel_dphy_remove(struct platform_device *pdev)
+{
+	struct mixel_dphy_priv *priv = platform_get_drvdata(pdev);
+
+	pm_runtime_disable(priv->dev);
+
+	return 0;
 }
 

 static struct platform_driver mixel_dphy_driver = {
 	.probe	= mixel_dphy_probe,
+	.remove = mixel_dphy_remove,
 	.driver = {
 		.name = "mixel-mipi-dphy",
 		.of_match_table	= mixel_dphy_of_match,



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Re: [PATCH v2 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm

[Lucas Stach]

Hi Guido,

this time hopefully with less broken quoting. My mailer is driving me
mad right now...

Am Mittwoch, dem 16.12.2020 um 12:27 +0100 schrieb Guido Günther:
> This allows us to shut down the mipi power domain on the imx8. The
> alternative would be to drop the dphy from the mipi power domain in the
> SOCs device tree and only have the DSI host controller visible there but
> since the PD is mostly about the PHY that would defeat it's purpose.

Adding RPM support is exactly the right course of action.

> This allows to shut off the power domain hen blanking the LCD panel:
> 
> pm_genpd_summary before:
> 
> domain                          status          slaves
>     /device                                             runtime status
> ----------------------------------------------------------------------
> mipi                            on
>     /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  unsupported
>     /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended
> 
> after:
> 
> mipi                            off-0
>     /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  suspended
>     /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended
> 
> Signed-off-by: Guido Günther <agx@sigxcpu.org>
> ---
>  .../phy/freescale/phy-fsl-imx8-mipi-dphy.c    | 22 ++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> index a95572b397ca..34e2d801e520 100644
> --- a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> +++ b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> @@ -14,6 +14,7 @@
>  #include <linux/of_platform.h>
>  #include <linux/phy/phy.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/regmap.h>
>  
>  /* DPHY registers */
> @@ -93,6 +94,7 @@ struct mixel_dphy_cfg {
>  };
>  
>  struct mixel_dphy_priv {
> +	struct device *dev;
>  	struct mixel_dphy_cfg cfg;
>  	struct regmap *regmap;
>  	struct clk *phy_ref_clk;
> @@ -382,6 +384,7 @@ static int mixel_dphy_power_on(struct phy *phy)
>  	ret = clk_prepare_enable(priv->phy_ref_clk);
>  	if (ret < 0)
>  		return ret;
> +	pm_runtime_get_sync(priv->dev);
>  

This call can fail and will leave you with an elevated rpm refcount.
Better use the new pm_runtime_resume_and_get to avoid this issue? 

Nitpick: I would add a blank line before the call.

Regards,
Lucas


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Re: [PATCH v2 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm

[Guido Günther]

Hi Lucas,
On Wed, Dec 16, 2020 at 01:05:36PM +0100, Lucas Stach wrote:
> Hi Guido,
> 
> this time hopefully with less broken quoting. My mailer is driving me
> mad right now...
> 
> Am Mittwoch, dem 16.12.2020 um 12:27 +0100 schrieb Guido Günther:
> > This allows us to shut down the mipi power domain on the imx8. The
> > alternative would be to drop the dphy from the mipi power domain in the
> > SOCs device tree and only have the DSI host controller visible there but
> > since the PD is mostly about the PHY that would defeat it's purpose.
> 
> Adding RPM support is exactly the right course of action.

Thanks for confirming!

> 
> > This allows to shut off the power domain hen blanking the LCD panel:
> > 
> > pm_genpd_summary before:
> > 
> > domain                          status          slaves
> >     /device                                             runtime status
> > ----------------------------------------------------------------------
> > mipi                            on
> >     /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  unsupported
> >     /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended
> > 
> > after:
> > 
> > mipi                            off-0
> >     /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  suspended
> >     /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended
> > 
> > Signed-off-by: Guido Günther <agx@sigxcpu.org>
> > ---
> >  .../phy/freescale/phy-fsl-imx8-mipi-dphy.c    | 22 ++++++++++++++++++-
> >  1 file changed, 21 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> > index a95572b397ca..34e2d801e520 100644
> > --- a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> > +++ b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> > @@ -14,6 +14,7 @@
> >  #include <linux/of_platform.h>
> >  #include <linux/phy/phy.h>
> >  #include <linux/platform_device.h>
> > +#include <linux/pm_runtime.h>
> >  #include <linux/regmap.h>
> >  
> >  /* DPHY registers */
> > @@ -93,6 +94,7 @@ struct mixel_dphy_cfg {
> >  };
> >  
> >  struct mixel_dphy_priv {
> > +	struct device *dev;
> >  	struct mixel_dphy_cfg cfg;
> >  	struct regmap *regmap;
> >  	struct clk *phy_ref_clk;
> > @@ -382,6 +384,7 @@ static int mixel_dphy_power_on(struct phy *phy)
> >  	ret = clk_prepare_enable(priv->phy_ref_clk);
> >  	if (ret < 0)
> >  		return ret;
> > +	pm_runtime_get_sync(priv->dev);
> >  
> 
> This call can fail and will leave you with an elevated rpm refcount.
> Better use the new pm_runtime_resume_and_get to avoid this issue?

pm_runtime_resume_and_get is a nice API addition indeed.

I added the error handling but opted to stay with `pm_runtime_get_sync`
in this case since the error path already has a pm_runtime_put() hence
avoiding another goto target.

> 
> Nitpick: I would add a blank line before the call.

Done.

Thanks for having a look!
 -- Guido

> 
> Regards,
> Lucas
> 

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Re: [PATCH v2 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm

[Liu Ying]

Hi Guido,

On Wed, 2020-12-16 at 12:27 +0100, Guido Günther wrote:
> This allows us to shut down the mipi power domain on the imx8. The
> alternative would be to drop the dphy from the mipi power domain in the
> SOCs device tree and only have the DSI host controller visible there but
> since the PD is mostly about the PHY that would defeat it's purpose.
> 
> This allows to shut off the power domain hen blanking the LCD panel:
> 
> pm_genpd_summary before:
> 
> domain                          status          slaves
>     /device                                             runtime status
> ----------------------------------------------------------------------
> mipi                            on
>     /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  unsupported
>     /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended
> 
> after:
> 
> mipi                            off-0
>     /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  suspended
>     /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended
> 
> Signed-off-by: Guido Günther <agx@sigxcpu.org>
> ---
>  .../phy/freescale/phy-fsl-imx8-mipi-dphy.c    | 22 ++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> index a95572b397ca..34e2d801e520 100644
> --- a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> +++ b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> @@ -14,6 +14,7 @@
>  #include <linux/of_platform.h>
>  #include <linux/phy/phy.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/regmap.h>
>  
>  /* DPHY registers */
> @@ -93,6 +94,7 @@ struct mixel_dphy_cfg {
>  };
>  
>  struct mixel_dphy_priv {
> +	struct device *dev;
>  	struct mixel_dphy_cfg cfg;
>  	struct regmap *regmap;
>  	struct clk *phy_ref_clk;
> @@ -382,6 +384,7 @@ static int mixel_dphy_power_on(struct phy *phy)
>  	ret = clk_prepare_enable(priv->phy_ref_clk);
>  	if (ret < 0)
>  		return ret;
> +	pm_runtime_get_sync(priv->dev);
>  
>  	phy_write(phy, PWR_ON, DPHY_PD_PLL);
>  	ret = regmap_read_poll_timeout(priv->regmap, DPHY_LOCK, locked,
> @@ -395,6 +398,7 @@ static int mixel_dphy_power_on(struct phy *phy)
>  
>  	return 0;
>  clock_disable:
> +	pm_runtime_put(priv->dev);
>  	clk_disable_unprepare(priv->phy_ref_clk);
>  	return ret;
>  }
> @@ -406,6 +410,7 @@ static int mixel_dphy_power_off(struct phy *phy)
>  	phy_write(phy, PWR_OFF, DPHY_PD_PLL);
>  	phy_write(phy, PWR_OFF, DPHY_PD_DPHY);
>  
> +	pm_runtime_put(priv->dev);
>  	clk_disable_unprepare(priv->phy_ref_clk);
>  
>  	return 0;
> @@ -467,6 +472,7 @@ static int mixel_dphy_probe(struct platform_device *pdev)
>  	dev_dbg(dev, "phy_ref clock rate: %lu\n",
>  		clk_get_rate(priv->phy_ref_clk));
>  
> +	priv->dev = dev;
>  	dev_set_drvdata(dev, priv);
>  
>  	phy = devm_phy_create(dev, np, &mixel_dphy_phy_ops);
> @@ -477,12 +483,26 @@ static int mixel_dphy_probe(struct platform_device *pdev)
>  	phy_set_drvdata(phy, priv);
>  
>  	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> +	if (IS_ERR(phy_provider))
> +		return PTR_ERR(phy_provider);
>  
> -	return PTR_ERR_OR_ZERO(phy_provider);
> +	pm_runtime_enable(dev);

If this enablement is done prior to devm_phy_create(), then the
phy-core will manage runtime PM for this device.  This way, this driver
doesn't have to manage it by itself.

Regards,
Liu Ying

> +
> +	return 0;
> +}
> +
> +static int mixel_dphy_remove(struct platform_device *pdev)
> +{
> +	struct mixel_dphy_priv *priv = platform_get_drvdata(pdev);
> +
> +	pm_runtime_disable(priv->dev);
> +
> +	return 0;
>  }
>  
>  static struct platform_driver mixel_dphy_driver = {
>  	.probe	= mixel_dphy_probe,
> +	.remove = mixel_dphy_remove,
>  	.driver = {
>  		.name = "mixel-mipi-dphy",
>  		.of_match_table	= mixel_dphy_of_match,


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Re: [PATCH v2 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm

[Liu Ying]

On Sat, 2021-02-20 at 13:37 +0800, Liu Ying wrote:
> Hi Guido,
> 
> On Wed, 2020-12-16 at 12:27 +0100, Guido Günther wrote:
> > This allows us to shut down the mipi power domain on the imx8. The
> > alternative would be to drop the dphy from the mipi power domain in the
> > SOCs device tree and only have the DSI host controller visible there but
> > since the PD is mostly about the PHY that would defeat it's purpose.
> > 
> > This allows to shut off the power domain hen blanking the LCD panel:
> > 
> > pm_genpd_summary before:
> > 
> > domain                          status          slaves
> >     /device                                             runtime status
> > ----------------------------------------------------------------------
> > mipi                            on
> >     /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  unsupported
> >     /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended
> > 
> > after:
> > 
> > mipi                            off-0
> >     /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  suspended
> >     /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended
> > 
> > Signed-off-by: Guido Günther <agx@sigxcpu.org>
> > ---
> >  .../phy/freescale/phy-fsl-imx8-mipi-dphy.c    | 22 ++++++++++++++++++-
> >  1 file changed, 21 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> > index a95572b397ca..34e2d801e520 100644
> > --- a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> > +++ b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> > @@ -14,6 +14,7 @@
> >  #include <linux/of_platform.h>
> >  #include <linux/phy/phy.h>
> >  #include <linux/platform_device.h>
> > +#include <linux/pm_runtime.h>
> >  #include <linux/regmap.h>
> >  
> >  /* DPHY registers */
> > @@ -93,6 +94,7 @@ struct mixel_dphy_cfg {
> >  };
> >  
> >  struct mixel_dphy_priv {
> > +	struct device *dev;
> >  	struct mixel_dphy_cfg cfg;
> >  	struct regmap *regmap;
> >  	struct clk *phy_ref_clk;
> > @@ -382,6 +384,7 @@ static int mixel_dphy_power_on(struct phy *phy)
> >  	ret = clk_prepare_enable(priv->phy_ref_clk);
> >  	if (ret < 0)
> >  		return ret;
> > +	pm_runtime_get_sync(priv->dev);
> >  
> >  	phy_write(phy, PWR_ON, DPHY_PD_PLL);
> >  	ret = regmap_read_poll_timeout(priv->regmap, DPHY_LOCK, locked,
> > @@ -395,6 +398,7 @@ static int mixel_dphy_power_on(struct phy *phy)
> >  
> >  	return 0;
> >  clock_disable:
> > +	pm_runtime_put(priv->dev);
> >  	clk_disable_unprepare(priv->phy_ref_clk);
> >  	return ret;
> >  }
> > @@ -406,6 +410,7 @@ static int mixel_dphy_power_off(struct phy *phy)
> >  	phy_write(phy, PWR_OFF, DPHY_PD_PLL);
> >  	phy_write(phy, PWR_OFF, DPHY_PD_DPHY);
> >  
> > +	pm_runtime_put(priv->dev);
> >  	clk_disable_unprepare(priv->phy_ref_clk);
> >  
> >  	return 0;
> > @@ -467,6 +472,7 @@ static int mixel_dphy_probe(struct platform_device *pdev)
> >  	dev_dbg(dev, "phy_ref clock rate: %lu\n",
> >  		clk_get_rate(priv->phy_ref_clk));
> >  
> > +	priv->dev = dev;
> >  	dev_set_drvdata(dev, priv);
> >  
> >  	phy = devm_phy_create(dev, np, &mixel_dphy_phy_ops);
> > @@ -477,12 +483,26 @@ static int mixel_dphy_probe(struct platform_device *pdev)
> >  	phy_set_drvdata(phy, priv);
> >  
> >  	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> > +	if (IS_ERR(phy_provider))
> > +		return PTR_ERR(phy_provider);
> >  
> > -	return PTR_ERR_OR_ZERO(phy_provider);
> > +	pm_runtime_enable(dev);
> 
> If this enablement is done prior to devm_phy_create(), then the
> phy-core will manage runtime PM for this device.  This way, this driver
> doesn't have to manage it by itself.
> 
> Regards,
> Liu Ying
> 
> > +
> > +	return 0;
> > +}
> > +
> > +static int mixel_dphy_remove(struct platform_device *pdev)
> > +{
> > +	struct mixel_dphy_priv *priv = platform_get_drvdata(pdev);
> > +
> > +	pm_runtime_disable(priv->dev);

One more comment - 'pm_runtime_disable(&pdev->dev);' is fine.

Regards,
Liu Ying

> > +
> > +	return 0;
> >  }
> >  
> >  static struct platform_driver mixel_dphy_driver = {
> >  	.probe	= mixel_dphy_probe,
> > +	.remove = mixel_dphy_remove,
> >  	.driver = {
> >  		.name = "mixel-mipi-dphy",
> >  		.of_match_table	= mixel_dphy_of_match,


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Re: [PATCH v2 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm

[Guido Günther]

Hi Liu,
On Sat, Feb 20, 2021 at 01:37:29PM +0800, Liu Ying wrote:
> Hi Guido,
> 
> On Wed, 2020-12-16 at 12:27 +0100, Guido Günther wrote:
> > This allows us to shut down the mipi power domain on the imx8. The
> > alternative would be to drop the dphy from the mipi power domain in the
> > SOCs device tree and only have the DSI host controller visible there but
> > since the PD is mostly about the PHY that would defeat it's purpose.
> > 
> > This allows to shut off the power domain hen blanking the LCD panel:
> > 
> > pm_genpd_summary before:
> > 
> > domain                          status          slaves
> >     /device                                             runtime status
> > ----------------------------------------------------------------------
> > mipi                            on
> >     /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  unsupported
> >     /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended
> > 
> > after:
> > 
> > mipi                            off-0
> >     /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  suspended
> >     /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended
> > 
> > Signed-off-by: Guido Günther <agx@sigxcpu.org>
> > ---
> >  .../phy/freescale/phy-fsl-imx8-mipi-dphy.c    | 22 ++++++++++++++++++-
> >  1 file changed, 21 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> > index a95572b397ca..34e2d801e520 100644
> > --- a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> > +++ b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> > @@ -14,6 +14,7 @@
> >  #include <linux/of_platform.h>
> >  #include <linux/phy/phy.h>
> >  #include <linux/platform_device.h>
> > +#include <linux/pm_runtime.h>
> >  #include <linux/regmap.h>
> >  
> >  /* DPHY registers */
> > @@ -93,6 +94,7 @@ struct mixel_dphy_cfg {
> >  };
> >  
> >  struct mixel_dphy_priv {
> > +	struct device *dev;
> >  	struct mixel_dphy_cfg cfg;
> >  	struct regmap *regmap;
> >  	struct clk *phy_ref_clk;
> > @@ -382,6 +384,7 @@ static int mixel_dphy_power_on(struct phy *phy)
> >  	ret = clk_prepare_enable(priv->phy_ref_clk);
> >  	if (ret < 0)
> >  		return ret;
> > +	pm_runtime_get_sync(priv->dev);
> >  
> >  	phy_write(phy, PWR_ON, DPHY_PD_PLL);
> >  	ret = regmap_read_poll_timeout(priv->regmap, DPHY_LOCK, locked,
> > @@ -395,6 +398,7 @@ static int mixel_dphy_power_on(struct phy *phy)
> >  
> >  	return 0;
> >  clock_disable:
> > +	pm_runtime_put(priv->dev);
> >  	clk_disable_unprepare(priv->phy_ref_clk);
> >  	return ret;
> >  }
> > @@ -406,6 +410,7 @@ static int mixel_dphy_power_off(struct phy *phy)
> >  	phy_write(phy, PWR_OFF, DPHY_PD_PLL);
> >  	phy_write(phy, PWR_OFF, DPHY_PD_DPHY);
> >  
> > +	pm_runtime_put(priv->dev);
> >  	clk_disable_unprepare(priv->phy_ref_clk);
> >  
> >  	return 0;
> > @@ -467,6 +472,7 @@ static int mixel_dphy_probe(struct platform_device *pdev)
> >  	dev_dbg(dev, "phy_ref clock rate: %lu\n",
> >  		clk_get_rate(priv->phy_ref_clk));
> >  
> > +	priv->dev = dev;
> >  	dev_set_drvdata(dev, priv);
> >  
> >  	phy = devm_phy_create(dev, np, &mixel_dphy_phy_ops);
> > @@ -477,12 +483,26 @@ static int mixel_dphy_probe(struct platform_device *pdev)
> >  	phy_set_drvdata(phy, priv);
> >  
> >  	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> > +	if (IS_ERR(phy_provider))
> > +		return PTR_ERR(phy_provider);
> >  
> > -	return PTR_ERR_OR_ZERO(phy_provider);
> > +	pm_runtime_enable(dev);
> 
> If this enablement is done prior to devm_phy_create(), then the
> phy-core will manage runtime PM for this device.  This way, this driver
> doesn't have to manage it by itself.

That makes things simpler indeed. Fixed in v4 together with your other
comment.
Thanks!
 -- Guido

> 
> Regards,
> Liu Ying
> 
> > +
> > +	return 0;
> > +}
> > +
> > +static int mixel_dphy_remove(struct platform_device *pdev)
> > +{
> > +	struct mixel_dphy_priv *priv = platform_get_drvdata(pdev);
> > +
> > +	pm_runtime_disable(priv->dev);
> > +
> > +	return 0;
> >  }
> >  
> >  static struct platform_driver mixel_dphy_driver = {
> >  	.probe	= mixel_dphy_probe,
> > +	.remove = mixel_dphy_remove,
> >  	.driver = {
> >  		.name = "mixel-mipi-dphy",
> >  		.of_match_table	= mixel_dphy_of_match,
> 

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