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

[Russell King - ARM Linux]

On Mon, Mar 13, 2017 at 10:57:20AM +0530, Keerthy wrote:
> 
> 
> 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.

That's there because I also boot non-DT from time to time, and having
the thermal driver still register means that I don't have to carry the
older hwmon implementation of the same around.  However, it can probably
be dropped for mainline at the expense of an additional small patch
carried locally.

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