[PATCH RFC 2/3] thermal: dove: convert to a thermal OF sensor device

[Keerthy]

On Monday 13 March 2017 12:37 AM, Russell King wrote:
> Convert the dove thermal infrastructure to an OF sensor device, and add
> the thermal zones for the SoC, with a critical trip point of 120°C.
> This allows us to specify thermal zones and couple them to cooling
> devices in DT.
>
> Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
> ---
>  arch/arm/boot/dts/dove.dtsi    | 17 +++++++++++++++++
>  drivers/thermal/dove_thermal.c | 33 +++++++++++++++++++++++++--------
>  2 files changed, 42 insertions(+), 8 deletions(-)
>
> diff --git a/arch/arm/boot/dts/dove.dtsi b/arch/arm/boot/dts/dove.dtsi
> index 698d58cea20d..40fb98687230 100644
> --- a/arch/arm/boot/dts/dove.dtsi
> +++ b/arch/arm/boot/dts/dove.dtsi
> @@ -455,6 +455,7 @@
>  				};
>
>  				thermal: thermal-diode at 001c {
> +					#thermal-sensor-cells = <0>;
>  					compatible = "marvell,dove-thermal";
>  					reg = <0x001c 0x0c>, <0x005c 0x08>;
>  				};
> @@ -800,4 +801,20 @@
>  			};
>  		};
>  	};
> +
> +	thermal-zones {
> +		soc-thermal {
> +			polling-delay-passive = <250>; /* ms */
> +			polling-delay = <1000>; /* ms */
> +			thermal-sensors = <&thermal>;
> +
> +			soc_trips: trips {
> +				soc_trip_crit: soc-crit {
> +					temperature = <120000>; /* °mC */
> +					hysteresis = <2000>; /* °mC */
> +					type = "critical";
> +				};
> +			};
> +		};
> +	};
>  };
> diff --git a/drivers/thermal/dove_thermal.c b/drivers/thermal/dove_thermal.c
> index a0bc9de42553..51b1a9e78576 100644
> --- a/drivers/thermal/dove_thermal.c
> +++ b/drivers/thermal/dove_thermal.c
> @@ -46,6 +46,7 @@
>  struct dove_thermal_priv {
>  	void __iomem *sensor;
>  	void __iomem *control;
> +	struct device *dev;
>  };
>
>  static int dove_init_sensor(const struct dove_thermal_priv *priv)
> @@ -92,17 +93,15 @@ static int dove_init_sensor(const struct dove_thermal_priv *priv)
>  	return 0;
>  }
>
> -static int dove_get_temp(struct thermal_zone_device *thermal,
> -			  int *temp)
> +static int dove_of_get_temp(void *data, int *temp)
>  {
> +	struct dove_thermal_priv *priv = data;
>  	unsigned long reg;
> -	struct dove_thermal_priv *priv = thermal->devdata;
>
>  	/* Valid check */
>  	reg = readl_relaxed(priv->control + PMU_TEMP_DIOD_CTRL1_REG);
>  	if ((reg & PMU_TDC1_TEMP_VALID_MASK) == 0x0) {
> -		dev_err(&thermal->device,
> -			"Temperature sensor reading not valid\n");
> +		dev_err(priv->dev, "Temperature sensor reading not valid\n");
>  		return -EIO;
>  	}
>
> @@ -118,10 +117,22 @@ static int dove_get_temp(struct thermal_zone_device *thermal,
>  	return 0;
>  }
>
> +static int dove_get_temp(struct thermal_zone_device *thermal,
> +			  int *temp)
> +{
> +	struct dove_thermal_priv *priv = thermal->devdata;
> +
> +	return dove_of_get_temp(priv, temp);
> +}
> +
>  static struct thermal_zone_device_ops ops = {
>  	.get_temp = dove_get_temp,
>  };
>
> +static const struct thermal_zone_of_device_ops of_ops = {
> +	.get_temp = dove_of_get_temp,
> +};
> +
>  static const struct of_device_id dove_thermal_id_table[] = {
>  	{ .compatible = "marvell,dove-thermal" },
>  	{}
> @@ -138,6 +149,8 @@ static int dove_thermal_probe(struct platform_device *pdev)
>  	if (!priv)
>  		return -ENOMEM;
>
> +	priv->dev = &pdev->dev;
> +
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	priv->sensor = devm_ioremap_resource(&pdev->dev, res);
>  	if (IS_ERR(priv->sensor))
> @@ -154,8 +167,11 @@ static int dove_thermal_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>
> -	thermal = thermal_zone_device_register("dove_thermal", 0, 0,
> -					       priv, &ops, NULL, 0, 0);
> +	thermal = devm_thermal_zone_of_sensor_register(&pdev->dev, 0,
> +						       priv, &of_ops);
> +	if (IS_ERR(thermal))
> +		thermal = thermal_zone_device_register("dove_thermal", 0, 0,
> +						       priv, &ops, NULL, 0, 0);
>  	if (IS_ERR(thermal)) {
>  		dev_err(&pdev->dev,
>  			"Failed to register thermal zone device\n");
> @@ -172,7 +188,8 @@ static int dove_thermal_exit(struct platform_device *pdev)
>  	struct thermal_zone_device *dove_thermal =
>  		platform_get_drvdata(pdev);
>
> -	thermal_zone_device_unregister(dove_thermal);
> +	if (!pdev->dev.of_node)
> +		thermal_zone_device_unregister(dove_thermal);

Russell,

Now that thermal-zones is defined in dove.dtsi do you see any need to 
call thermal_zone_device_register? Is there a case where in 
devm_thermal_zone_of_sensor_register is known to fail?

If not then we can even get rid of ops, dove_get_temp function.

Regards,
Keerthy

>
>  	return 0;
>  }
>