Re: [PATCH] cpufreq: imx6q/thermal: imx: move CPU cooling device from thermal to cpufreq

[Shawn Guo <shawnguo@kernel.org>]

On Wed, Nov 15, 2017 at 10:23:32AM +0100, Bastian Stender wrote:
> The cooling device should be part of the i.MX cpufreq driver. So move
> it there.
> 
> Use of_cpufreq_power_cooling_register 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>

I'm fine with the patch, but I would invite Leonard to take a look.

Shawn

> ---
> 
> This is a rework of "thermal: imx: use cpufreq cooling of
> registration method" (id:20171103164203.5805-1-bst@pengutronix.de) and a
> merged version of the follow-up patches "thermal: imx: remove cooling
> device" (id:20171114134829.1354-1-bst@pengutronix.de) and "cpufreq:
> imx6q: add CPU as cooling device"
> (id:20171114135128.6173-1-bst@pengutronix.de).
> ---
>  drivers/cpufreq/imx6q-cpufreq.c | 37 +++++++++++++++++++++++++++++++++++++
>  drivers/thermal/imx_thermal.c   | 15 ---------------
>  2 files changed, 37 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
> index 14466a9b01c0..6c7c59766990 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>
> @@ -35,6 +36,7 @@ static struct clk *pll2_bus_clk;
>  static struct clk *secondary_sel_clk;
>  
>  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 transition_latency;
> @@ -169,6 +171,32 @@ static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
>  	return 0;
>  }
>  
> +static void imx6q_cpufreq_ready(struct cpufreq_policy *policy)
> +{
> +	struct device_node *np = of_node_get(cpu_dev->of_node);
> +	u32 capacitance = 0;
> +
> +	if (WARN_ON(!np))
> +		return;
> +
> +	if (of_find_property(np, "#cooling-cells", NULL)) {
> +		of_property_read_u32(np, "dynamic-power-coefficient", &capacitance);
> +
> +		cdev = of_cpufreq_power_cooling_register(np,
> +						policy, capacitance, NULL);
> +
> +		if (IS_ERR(cdev)) {
> +			dev_err(cpu_dev,
> +				"running cpufreq without cooling device: %ld\n",
> +				PTR_ERR(cdev));
> +
> +			cdev = NULL;
> +		}
> +	}
> +
> +	of_node_put(np);
> +}
> +
>  static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
>  {
>  	int ret;
> @@ -180,13 +208,22 @@ 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 4798b4b1fd77..3bdbde675698 100644
> --- a/drivers/thermal/imx_thermal.c
> +++ b/drivers/thermal/imx_thermal.c
> @@ -91,7 +91,6 @@ static struct thermal_soc_data thermal_imx6sx_data = {
>  struct imx_thermal_data {
>  	struct cpufreq_policy *policy;
>  	struct thermal_zone_device *tz;
> -	struct thermal_cooling_device *cdev;
>  	enum thermal_device_mode mode;
>  	struct regmap *tempmon;
>  	u32 c1, c2; /* See formula in imx_get_sensor_data() */
> @@ -533,22 +532,12 @@ 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);
> -		dev_err(&pdev->dev,
> -			"failed to register cpufreq cooling device: %d\n", ret);
> -		cpufreq_cpu_put(data->policy);
> -		return ret;
> -	}
> -
>  	data->thermal_clk = devm_clk_get(&pdev->dev, NULL);
>  	if (IS_ERR(data->thermal_clk)) {
>  		ret = PTR_ERR(data->thermal_clk);
>  		if (ret != -EPROBE_DEFER)
>  			dev_err(&pdev->dev,
>  				"failed to get thermal clk: %d\n", ret);
> -		cpufreq_cooling_unregister(data->cdev);
>  		cpufreq_cpu_put(data->policy);
>  		return ret;
>  	}
> @@ -563,7 +552,6 @@ static int imx_thermal_probe(struct platform_device *pdev)
>  	ret = clk_prepare_enable(data->thermal_clk);
>  	if (ret) {
>  		dev_err(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
> -		cpufreq_cooling_unregister(data->cdev);
>  		cpufreq_cpu_put(data->policy);
>  		return ret;
>  	}
> @@ -579,7 +567,6 @@ static int imx_thermal_probe(struct platform_device *pdev)
>  		dev_err(&pdev->dev,
>  			"failed to register thermal zone device %d\n", ret);
>  		clk_disable_unprepare(data->thermal_clk);
> -		cpufreq_cooling_unregister(data->cdev);
>  		cpufreq_cpu_put(data->policy);
>  		return ret;
>  	}
> @@ -608,7 +595,6 @@ static int imx_thermal_probe(struct platform_device *pdev)
>  		dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
>  		clk_disable_unprepare(data->thermal_clk);
>  		thermal_zone_device_unregister(data->tz);
> -		cpufreq_cooling_unregister(data->cdev);
>  		cpufreq_cpu_put(data->policy);
>  		return ret;
>  	}
> @@ -630,7 +616,6 @@ static int imx_thermal_remove(struct platform_device *pdev)
>  		clk_disable_unprepare(data->thermal_clk);
>  
>  	thermal_zone_device_unregister(data->tz);
> -	cpufreq_cooling_unregister(data->cdev);
>  	cpufreq_cpu_put(data->policy);
>  
>  	return 0;
> -- 
> 2.11.0
>