* Re: [PATCH v2 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm
2020-12-16 11:27 ` [PATCH v2 1/1] " Guido Günther
@ 2020-12-16 11:58 ` Lucas Stach
2020-12-16 12:05 ` Lucas Stach
2021-02-20 5:37 ` Liu Ying
2 siblings, 0 replies; 8+ messages in thread
From: Lucas Stach @ 2020-12-16 11:58 UTC (permalink / raw)
To: Guido Günther, Kishon Vijay Abraham I, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam,
NXP Linux Team, Robert Chiras, Sam Ravnborg, linux-kernel,
linux-arm-kernel
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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^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH v2 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm
2020-12-16 11:27 ` [PATCH v2 1/1] " Guido Günther
2020-12-16 11:58 ` Lucas Stach
@ 2020-12-16 12:05 ` Lucas Stach
2020-12-16 18:25 ` Guido Günther
2021-02-20 5:37 ` Liu Ying
2 siblings, 1 reply; 8+ messages in thread
From: Lucas Stach @ 2020-12-16 12:05 UTC (permalink / raw)
To: Guido Günther, Kishon Vijay Abraham I, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam,
NXP Linux Team, Robert Chiras, Sam Ravnborg, linux-kernel,
linux-arm-kernel
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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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH v2 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm
2020-12-16 12:05 ` Lucas Stach
@ 2020-12-16 18:25 ` Guido Günther
0 siblings, 0 replies; 8+ messages in thread
From: Guido Günther @ 2020-12-16 18:25 UTC (permalink / raw)
To: Lucas Stach
Cc: Sam Ravnborg, Shawn Guo, Sascha Hauer, linux-kernel,
Kishon Vijay Abraham I, NXP Linux Team, Pengutronix Kernel Team,
Robert Chiras, Fabio Estevam, linux-arm-kernel
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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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm
2020-12-16 11:27 ` [PATCH v2 1/1] " Guido Günther
2020-12-16 11:58 ` Lucas Stach
2020-12-16 12:05 ` Lucas Stach
@ 2021-02-20 5:37 ` Liu Ying
2021-02-20 5:50 ` Liu Ying
2021-02-22 18:39 ` Guido Günther
2 siblings, 2 replies; 8+ messages in thread
From: Liu Ying @ 2021-02-20 5:37 UTC (permalink / raw)
To: Guido Günther, Kishon Vijay Abraham I, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam,
NXP Linux Team, Robert Chiras, Sam Ravnborg, linux-kernel,
linux-arm-kernel
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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^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH v2 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm
2021-02-20 5:37 ` Liu Ying
@ 2021-02-20 5:50 ` Liu Ying
2021-02-22 18:39 ` Guido Günther
1 sibling, 0 replies; 8+ messages in thread
From: Liu Ying @ 2021-02-20 5:50 UTC (permalink / raw)
To: Guido Günther, Kishon Vijay Abraham I, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam,
NXP Linux Team, Robert Chiras, Sam Ravnborg, linux-kernel,
linux-arm-kernel
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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^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH v2 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm
2021-02-20 5:37 ` Liu Ying
2021-02-20 5:50 ` Liu Ying
@ 2021-02-22 18:39 ` Guido Günther
1 sibling, 0 replies; 8+ messages in thread
From: Guido Günther @ 2021-02-22 18:39 UTC (permalink / raw)
To: Liu Ying
Cc: Sam Ravnborg, Shawn Guo, Sascha Hauer, linux-kernel,
Kishon Vijay Abraham I, NXP Linux Team, Pengutronix Kernel Team,
Robert Chiras, Fabio Estevam, linux-arm-kernel
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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^ permalink raw reply [flat|nested] 8+ messages in thread