[PATCH v3 1/2] cpufreq: imx6q/thermal: imx: register cooling device depending on OF

[PATCH v3 1/2] cpufreq: imx6q/thermal: imx: register cooling device depending on OF

[Bastian Stender]

The cooling device should be part of the i.MX cpufreq driver, but it
cannot be removed for the sake of DT stability. So turn the cooling
device registration into a separate function and perform the
registration only if the CPU OF node does not have the #cooling-cells
property.

Use of_cpufreq_power_cooling_register in imx_thermal code to link the
cooling device to the device tree node provided.

This makes it possible to bind the cpufreq cooling device to a custom
thermal zone via a cooling-maps entry like:

	cooling-maps {
		map0 {
			trip = <&board_alert>;
			cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
		};
	};

Assuming a cpu node exists with label "cpu0" and #cooling-cells
property.

Signed-off-by: Bastian Stender <bst@pengutronix.de>
---
Changes since v2:
- replace of_cpufreq_power_cooling_register with
  of_cpufreq_cooling_register already handling capacitance/#cooling-cells
  properties

Changes since implicit v1 ("cpufreq: imx6q/thermal: imx: move CPU cooling device from thermal to cpufreq",
id:20171115092332.9320-1-bst@pengutronix.de):

- create cooling device in imx_thermal in case no #cooling-cells
  property is available instead of removing it (DT stability)
- fix indentation
---
 drivers/cpufreq/imx6q-cpufreq.c | 21 +++++++++++++++++++++
 drivers/thermal/imx_thermal.c   | 28 ++++++++++++++++++++++++----
 2 files changed, 45 insertions(+), 4 deletions(-)

diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
index 83cf631fc9bc..a9259fb0302f 100644
--- a/drivers/cpufreq/imx6q-cpufreq.c
+++ b/drivers/cpufreq/imx6q-cpufreq.c
@@ -9,6 +9,7 @@
 #include <linux/clk.h>
 #include <linux/cpu.h>
 #include <linux/cpufreq.h>
+#include <linux/cpu_cooling.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -50,6 +51,7 @@ static struct clk_bulk_data clks[] = {
 };
 
 static struct device *cpu_dev;
+static struct thermal_cooling_device *cdev;
 static bool free_opp;
 static struct cpufreq_frequency_table *freq_table;
 static unsigned int max_freq;
@@ -191,6 +193,16 @@ static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
 	return 0;
 }
 
+static void imx6q_cpufreq_ready(struct cpufreq_policy *policy)
+{
+	cdev = of_cpufreq_cooling_register(policy);
+
+	if (!cdev)
+		dev_err(cpu_dev,
+			"running cpufreq without cooling device: %ld\n",
+			PTR_ERR(cdev));
+}
+
 static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
 {
 	int ret;
@@ -202,13 +214,22 @@ static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
 	return ret;
 }
 
+static int imx6q_cpufreq_exit(struct cpufreq_policy *policy)
+{
+	cpufreq_cooling_unregister(cdev);
+
+	return 0;
+}
+
 static struct cpufreq_driver imx6q_cpufreq_driver = {
 	.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify = cpufreq_generic_frequency_table_verify,
 	.target_index = imx6q_set_target,
 	.get = cpufreq_generic_get,
 	.init = imx6q_cpufreq_init,
+	.exit = imx6q_cpufreq_exit,
 	.name = "imx6q-cpufreq",
+	.ready = imx6q_cpufreq_ready,
 	.attr = cpufreq_generic_attr,
 	.suspend = cpufreq_generic_suspend,
 };
diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
index 334d98be03b9..cbfcca828cd7 100644
--- a/drivers/thermal/imx_thermal.c
+++ b/drivers/thermal/imx_thermal.c
@@ -3,6 +3,7 @@
 // Copyright 2013 Freescale Semiconductor, Inc.
 
 #include <linux/clk.h>
+#include <linux/cpu.h>
 #include <linux/cpufreq.h>
 #include <linux/cpu_cooling.h>
 #include <linux/delay.h>
@@ -644,6 +645,27 @@ static const struct of_device_id of_imx_thermal_match[] = {
 };
 MODULE_DEVICE_TABLE(of, of_imx_thermal_match);
 
+/*
+ * Create cooling device in case no #cooling-cells property is available in
+ * CPU node
+ */
+static int imx_thermal_register_legacy_cooling(struct imx_thermal_data *data)
+{
+	struct device_node *np = of_get_cpu_node(data->policy->cpu, NULL);
+	int ret;
+
+	if (!np || !of_find_property(np, "#cooling-cells", NULL)) {
+		data->cdev = cpufreq_cooling_register(data->policy);
+		if (IS_ERR(data->cdev)) {
+			ret = PTR_ERR(data->cdev);
+			cpufreq_cpu_put(data->policy);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
 static int imx_thermal_probe(struct platform_device *pdev)
 {
 	struct imx_thermal_data *data;
@@ -724,12 +746,10 @@ static int imx_thermal_probe(struct platform_device *pdev)
 		return -EPROBE_DEFER;
 	}
 
-	data->cdev = cpufreq_cooling_register(data->policy);
-	if (IS_ERR(data->cdev)) {
-		ret = PTR_ERR(data->cdev);
+	ret = imx_thermal_register_legacy_cooling(data);
+	if (ret) {
 		dev_err(&pdev->dev,
 			"failed to register cpufreq cooling device: %d\n", ret);
-		cpufreq_cpu_put(data->policy);
 		return ret;
 	}
 
-- 
2.17.1

[PATCH v3 2/2] ARM: dts: imx: add cooling-cells for cpufreq cooling device

[Bastian Stender]

From: Anson Huang <Anson.Huang@nxp.com>

Add #cooling-cells for i.MX6/7 SoCs for cpufreq cooling device usage.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Bastian Stender <bst@pengutronix.de>
---
Changes since (implicit) v1:

- add Signed-off-by
---
 arch/arm/boot/dts/imx6dl.dtsi | 1 +
 arch/arm/boot/dts/imx6q.dtsi  | 1 +
 arch/arm/boot/dts/imx6sl.dtsi | 1 +
 arch/arm/boot/dts/imx6sx.dtsi | 1 +
 arch/arm/boot/dts/imx6ul.dtsi | 1 +
 arch/arm/boot/dts/imx7d.dtsi  | 1 +
 6 files changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/imx6dl.dtsi b/arch/arm/boot/dts/imx6dl.dtsi
index 558bce81209d..b830dfd74ad3 100644
--- a/arch/arm/boot/dts/imx6dl.dtsi
+++ b/arch/arm/boot/dts/imx6dl.dtsi
@@ -39,6 +39,7 @@
 				396000	1175000
 			>;
 			clock-latency = <61036>; /* two CLK32 periods */
+			#cooling-cells = <2>;
 			clocks = <&clks IMX6QDL_CLK_ARM>,
 				 <&clks IMX6QDL_CLK_PLL2_PFD2_396M>,
 				 <&clks IMX6QDL_CLK_STEP>,
diff --git a/arch/arm/boot/dts/imx6q.dtsi b/arch/arm/boot/dts/imx6q.dtsi
index ae7b3f107893..ac9f5cb65dec 100644
--- a/arch/arm/boot/dts/imx6q.dtsi
+++ b/arch/arm/boot/dts/imx6q.dtsi
@@ -44,6 +44,7 @@
 				396000	1175000
 			>;
 			clock-latency = <61036>; /* two CLK32 periods */
+			#cooling-cells = <2>;
 			clocks = <&clks IMX6QDL_CLK_ARM>,
 				 <&clks IMX6QDL_CLK_PLL2_PFD2_396M>,
 				 <&clks IMX6QDL_CLK_STEP>,
diff --git a/arch/arm/boot/dts/imx6sl.dtsi b/arch/arm/boot/dts/imx6sl.dtsi
index ab6a7e2e7e8f..d35d4e93236a 100644
--- a/arch/arm/boot/dts/imx6sl.dtsi
+++ b/arch/arm/boot/dts/imx6sl.dtsi
@@ -65,6 +65,7 @@
 				396000          1175000
 			>;
 			clock-latency = <61036>; /* two CLK32 periods */
+			#cooling-cells = <2>;
 			clocks = <&clks IMX6SL_CLK_ARM>, <&clks IMX6SL_CLK_PLL2_PFD2>,
 					<&clks IMX6SL_CLK_STEP>, <&clks IMX6SL_CLK_PLL1_SW>,
 					<&clks IMX6SL_CLK_PLL1_SYS>;
diff --git a/arch/arm/boot/dts/imx6sx.dtsi b/arch/arm/boot/dts/imx6sx.dtsi
index 49c7205b8db8..966e39a99792 100644
--- a/arch/arm/boot/dts/imx6sx.dtsi
+++ b/arch/arm/boot/dts/imx6sx.dtsi
@@ -83,6 +83,7 @@
 				198000	    1175000
 			>;
 			clock-latency = <61036>; /* two CLK32 periods */
+			#cooling-cells = <2>;
 			clocks = <&clks IMX6SX_CLK_ARM>,
 				 <&clks IMX6SX_CLK_PLL2_PFD2>,
 				 <&clks IMX6SX_CLK_STEP>,
diff --git a/arch/arm/boot/dts/imx6ul.dtsi b/arch/arm/boot/dts/imx6ul.dtsi
index 1241972b16ba..14b6ac78d323 100644
--- a/arch/arm/boot/dts/imx6ul.dtsi
+++ b/arch/arm/boot/dts/imx6ul.dtsi
@@ -66,6 +66,7 @@
 			device_type = "cpu";
 			reg = <0>;
 			clock-latency = <61036>; /* two CLK32 periods */
+			#cooling-cells = <2>;
 			operating-points = <
 				/* kHz	uV */
 				696000	1275000
diff --git a/arch/arm/boot/dts/imx7d.dtsi b/arch/arm/boot/dts/imx7d.dtsi
index 200714e3feea..4991371734d9 100644
--- a/arch/arm/boot/dts/imx7d.dtsi
+++ b/arch/arm/boot/dts/imx7d.dtsi
@@ -53,6 +53,7 @@
 				792000	975000
 			>;
 			clock-frequency = <996000000>;
+			#cooling-cells = <2>;
 		};
 
 		cpu1: cpu@1 {
-- 
2.17.1

Re: [PATCH v3 1/2] cpufreq: imx6q/thermal: imx: register cooling device depending on OF

[Lucas Stach]

Am Freitag, den 08.06.2018, 11:06 +0200 schrieb Bastian Stender:
> The cooling device should be part of the i.MX cpufreq driver, but it
> cannot be removed for the sake of DT stability. So turn the cooling
> device registration into a separate function and perform the
> registration only if the CPU OF node does not have the #cooling-cells
> property.
> 
> Use of_cpufreq_power_cooling_register in imx_thermal code to link the
> cooling device to the device tree node provided.
> 
> This makes it possible to bind the cpufreq cooling device to a custom
> thermal zone via a cooling-maps entry like:
> 
> 	cooling-maps {
> > 		map0 {
> > 			trip = <&board_alert>;
> > 			cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
> > 		};
> 	};
> 
> Assuming a cpu node exists with label "cpu0" and #cooling-cells
> property.
> 
> Signed-off-by: Bastian Stender <bst@pengutronix.de>

Reviewed-by: Lucas Stach <l.stach@pengutronix.de>

> ---
> Changes since v2:
> - replace of_cpufreq_power_cooling_register with
>   of_cpufreq_cooling_register already handling capacitance/#cooling-cells
>   properties
> 
> Changes since implicit v1 ("cpufreq: imx6q/thermal: imx: move CPU cooling device from thermal to cpufreq",
> > id:20171115092332.9320-1-bst@pengutronix.de):
> 
> - create cooling device in imx_thermal in case no #cooling-cells
>   property is available instead of removing it (DT stability)
> - fix indentation
> ---
>  drivers/cpufreq/imx6q-cpufreq.c | 21 +++++++++++++++++++++
>  drivers/thermal/imx_thermal.c   | 28 ++++++++++++++++++++++++----
>  2 files changed, 45 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
> index 83cf631fc9bc..a9259fb0302f 100644
> --- a/drivers/cpufreq/imx6q-cpufreq.c
> +++ b/drivers/cpufreq/imx6q-cpufreq.c
> @@ -9,6 +9,7 @@
>  #include <linux/clk.h>
>  #include <linux/cpu.h>
>  #include <linux/cpufreq.h>
> +#include <linux/cpu_cooling.h>
>  #include <linux/err.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> @@ -50,6 +51,7 @@ static struct clk_bulk_data clks[] = {
>  };
>  
>  static struct device *cpu_dev;
> +static struct thermal_cooling_device *cdev;
>  static bool free_opp;
>  static struct cpufreq_frequency_table *freq_table;
>  static unsigned int max_freq;
> @@ -191,6 +193,16 @@ static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
> >  	return 0;
>  }
>  
> +static void imx6q_cpufreq_ready(struct cpufreq_policy *policy)
> +{
> > +	cdev = of_cpufreq_cooling_register(policy);
> +
> > +	if (!cdev)
> > +		dev_err(cpu_dev,
> > +			"running cpufreq without cooling device: %ld\n",
> > +			PTR_ERR(cdev));
> +}
> +
>  static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
>  {
> >  	int ret;
> @@ -202,13 +214,22 @@ static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
> >  	return ret;
>  }
>  
> +static int imx6q_cpufreq_exit(struct cpufreq_policy *policy)
> +{
> > +	cpufreq_cooling_unregister(cdev);
> +
> > +	return 0;
> +}
> +
>  static struct cpufreq_driver imx6q_cpufreq_driver = {
> >  	.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
> >  	.verify = cpufreq_generic_frequency_table_verify,
> >  	.target_index = imx6q_set_target,
> >  	.get = cpufreq_generic_get,
> >  	.init = imx6q_cpufreq_init,
> > +	.exit = imx6q_cpufreq_exit,
> >  	.name = "imx6q-cpufreq",
> > +	.ready = imx6q_cpufreq_ready,
> >  	.attr = cpufreq_generic_attr,
> >  	.suspend = cpufreq_generic_suspend,
>  };
> diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
> index 334d98be03b9..cbfcca828cd7 100644
> --- a/drivers/thermal/imx_thermal.c
> +++ b/drivers/thermal/imx_thermal.c
> @@ -3,6 +3,7 @@
>  // Copyright 2013 Freescale Semiconductor, Inc.
>  
>  #include <linux/clk.h>
> +#include <linux/cpu.h>
>  #include <linux/cpufreq.h>
>  #include <linux/cpu_cooling.h>
>  #include <linux/delay.h>
> @@ -644,6 +645,27 @@ static const struct of_device_id of_imx_thermal_match[] = {
>  };
>  MODULE_DEVICE_TABLE(of, of_imx_thermal_match);
>  
> +/*
> + * Create cooling device in case no #cooling-cells property is available in
> + * CPU node
> + */
> +static int imx_thermal_register_legacy_cooling(struct imx_thermal_data *data)
> +{
> > +	struct device_node *np = of_get_cpu_node(data->policy->cpu, NULL);
> > +	int ret;
> +
> > +	if (!np || !of_find_property(np, "#cooling-cells", NULL)) {
> > +		data->cdev = cpufreq_cooling_register(data->policy);
> > +		if (IS_ERR(data->cdev)) {
> > +			ret = PTR_ERR(data->cdev);
> > +			cpufreq_cpu_put(data->policy);
> > +			return ret;
> > +		}
> > +	}
> +
> > +	return 0;
> +}
> +
>  static int imx_thermal_probe(struct platform_device *pdev)
>  {
> >  	struct imx_thermal_data *data;
> @@ -724,12 +746,10 @@ static int imx_thermal_probe(struct platform_device *pdev)
> >  		return -EPROBE_DEFER;
> >  	}
>  
> > -	data->cdev = cpufreq_cooling_register(data->policy);
> > -	if (IS_ERR(data->cdev)) {
> > -		ret = PTR_ERR(data->cdev);
> > +	ret = imx_thermal_register_legacy_cooling(data);
> > +	if (ret) {
> >  		dev_err(&pdev->dev,
> >  			"failed to register cpufreq cooling device: %d\n", ret);
> > -		cpufreq_cpu_put(data->policy);
> >  		return ret;
> >  	}
>  

Re: [PATCH v3 1/2] cpufreq: imx6q/thermal: imx: register cooling device depending on OF

[Viresh Kumar]

On 08-06-18, 11:06, Bastian Stender wrote:
> The cooling device should be part of the i.MX cpufreq driver, but it
> cannot be removed for the sake of DT stability.

I am not sure what you meant by DT stability here. Can you please explain that ?
What about calling both OF and non-OF calls from the cpufreq driver, based on
the fact that data is present in DT or not ?

-- 
viresh

Re: [PATCH v3 2/2] ARM: dts: imx: add cooling-cells for cpufreq cooling device

[Viresh Kumar]

On 08-06-18, 11:06, Bastian Stender wrote:
> From: Anson Huang <Anson.Huang@nxp.com>
> 
> Add #cooling-cells for i.MX6/7 SoCs for cpufreq cooling device usage.
> 
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> Signed-off-by: Bastian Stender <bst@pengutronix.de>
> ---
> Changes since (implicit) v1:
> 
> - add Signed-off-by
> ---
>  arch/arm/boot/dts/imx6dl.dtsi | 1 +
>  arch/arm/boot/dts/imx6q.dtsi  | 1 +
>  arch/arm/boot/dts/imx6sl.dtsi | 1 +
>  arch/arm/boot/dts/imx6sx.dtsi | 1 +
>  arch/arm/boot/dts/imx6ul.dtsi | 1 +
>  arch/arm/boot/dts/imx7d.dtsi  | 1 +

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

-- 
viresh

Re: [PATCH v3 1/2] cpufreq: imx6q/thermal: imx: register cooling device depending on OF

[Lucas Stach]

Hi Viresh,

Am Dienstag, den 19.06.2018, 14:35 +0530 schrieb Viresh Kumar:
> On 08-06-18, 11:06, Bastian Stender wrote:
> > The cooling device should be part of the i.MX cpufreq driver, but it
> > cannot be removed for the sake of DT stability.
> 
> I am not sure what you meant by DT stability here. Can you please explain that ?

The goal that we strive for in i.MX land is that a any newer kernel
boots on a older DT without functional regressions compared to a
matching DT/kernel pair when possible.

> What about calling both OF and non-OF calls from the cpufreq driver, based on
> the fact that data is present in DT or not ?

That's right, we could move the cooling device registration completely
to the cpufreq driver. As that would consolidate the code some more, I
agree that this is the right way to go.

Regards,
Lucas

Re: [PATCH v3 1/2] cpufreq: imx6q/thermal: imx: register cooling device depending on OF

[Viresh Kumar]

On 19-06-18, 11:22, Lucas Stach wrote:
> Hi Viresh,
> 
> Am Dienstag, den 19.06.2018, 14:35 +0530 schrieb Viresh Kumar:
> > On 08-06-18, 11:06, Bastian Stender wrote:
> > > The cooling device should be part of the i.MX cpufreq driver, but it
> > > cannot be removed for the sake of DT stability.
> > 
> > I am not sure what you meant by DT stability here. Can you please explain that ?
> 
> The goal that we strive for in i.MX land is that a any newer kernel
> boots on a older DT without functional regressions compared to a
> matching DT/kernel pair when possible.

Right, that's being backwards compatible and we must do that.

> > What about calling both OF and non-OF calls from the cpufreq driver, based on
> > the fact that data is present in DT or not ?
> 
> That's right, we could move the cooling device registration completely
> to the cpufreq driver. As that would consolidate the code some more, I
> agree that this is the right way to go.

We are good to go then :)

-- 
viresh

Re: [PATCH v3 2/2] ARM: dts: imx: add cooling-cells for cpufreq cooling device

[Shawn Guo]

On Fri, Jun 08, 2018 at 11:06:40AM +0200, Bastian Stender wrote:
> From: Anson Huang <Anson.Huang@nxp.com>
> 
> Add #cooling-cells for i.MX6/7 SoCs for cpufreq cooling device usage.
> 
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> Signed-off-by: Bastian Stender <bst@pengutronix.de>

Applied this one, thanks.

Re: [PATCH v3 1/2] cpufreq: imx6q/thermal: imx: register cooling device depending on OF

[Rafael J. Wysocki]

On Tuesday, June 19, 2018 11:31:57 AM CEST Viresh Kumar wrote:
> On 19-06-18, 11:22, Lucas Stach wrote:
> > Hi Viresh,
> > 
> > Am Dienstag, den 19.06.2018, 14:35 +0530 schrieb Viresh Kumar:
> > > On 08-06-18, 11:06, Bastian Stender wrote:
> > > > The cooling device should be part of the i.MX cpufreq driver, but it
> > > > cannot be removed for the sake of DT stability.
> > > 
> > > I am not sure what you meant by DT stability here. Can you please explain that ?
> > 
> > The goal that we strive for in i.MX land is that a any newer kernel
> > boots on a older DT without functional regressions compared to a
> > matching DT/kernel pair when possible.
> 
> Right, that's being backwards compatible and we must do that.
> 
> > > What about calling both OF and non-OF calls from the cpufreq driver, based on
> > > the fact that data is present in DT or not ?
> > 
> > That's right, we could move the cooling device registration completely
> > to the cpufreq driver. As that would consolidate the code some more, I
> > agree that this is the right way to go.
> 
> We are good to go then :)

So I've applied the patch.

Thanks!