Thermal: Dove: Add Themal sensor support for Dove.

The Marvell Dove SoC has a thermal sensor. Add a driver using the
thermal framework.

Signed-off-by: Andrew Lunn <[e-mail]>
Signed-off-by: Sebastian Hesselbarth <[e-mail]>
Signed-off-by: Zhang Rui <[e-mail]>

Documentation/devicetree/bindings/thermal/dove-thermal.txt

···
+* Dove Thermal
+
+This driver is for Dove SoCs which contain a thermal sensor.
+
+Required properties:
+- compatible : "marvell,dove-thermal"
+- reg : Address range of the thermal registers
+
+The reg properties should contain two ranges. The first is for the
+three Thermal Manager registers, while the second range contains the
+Thermal Diode Control Registers.
+
+Example:
+
+	thermal@10078 {
+		compatible = "marvell,dove-thermal";
+		reg = <0xd001c 0x0c>, <0xd005c 0x08>;
+	};

drivers/thermal/Kconfig

···
 	  device directory to support emulation mode. With emulation mode sysfs
 	  node, you can manually input temperature to TMU for simulation purpose.
 
+config DOVE_THERMAL
+	tristate "Temperature sensor on Marvell Dove SoCs"
+	depends on ARCH_DOVE
+	depends on OF
+	help
+	  Support for the Dove thermal sensor driver in the Linux thermal
+	  framework.
+
 config DB8500_THERMAL
 	bool "DB8500 thermal management"
 	depends on ARCH_U8500

drivers/thermal/Makefile

···
 obj-$(CONFIG_RCAR_THERMAL)	+= rcar_thermal.o
 obj-$(CONFIG_KIRKWOOD_THERMAL)  += kirkwood_thermal.o
 obj-$(CONFIG_EXYNOS_THERMAL)	+= exynos_thermal.o
+obj-$(CONFIG_DOVE_THERMAL)  	+= dove_thermal.o
 obj-$(CONFIG_DB8500_THERMAL)	+= db8500_thermal.o
 obj-$(CONFIG_DB8500_CPUFREQ_COOLING)	+= db8500_cpufreq_cooling.o
 obj-$(CONFIG_INTEL_POWERCLAMP)	+= intel_powerclamp.o

drivers/thermal/dove_thermal.c

···
+/*
+ * Dove thermal sensor driver
+ *
+ * Copyright (C) 2013 Andrew Lunn <[e-mail]>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/thermal.h>
+
+#define DOVE_THERMAL_TEMP_OFFSET	1
+#define DOVE_THERMAL_TEMP_MASK		0x1FF
+
+/* Dove Thermal Manager Control and Status Register */
+#define PMU_TM_DISABLE_OFFS		0
+#define PMU_TM_DISABLE_MASK		(0x1 << PMU_TM_DISABLE_OFFS)
+
+/* Dove Theraml Diode Control 0 Register */
+#define PMU_TDC0_SW_RST_MASK		(0x1 << 1)
+#define PMU_TDC0_SEL_VCAL_OFFS		5
+#define PMU_TDC0_SEL_VCAL_MASK		(0x3 << PMU_TDC0_SEL_VCAL_OFFS)
+#define PMU_TDC0_REF_CAL_CNT_OFFS	11
+#define PMU_TDC0_REF_CAL_CNT_MASK	(0x1FF << PMU_TDC0_REF_CAL_CNT_OFFS)
+#define PMU_TDC0_AVG_NUM_OFFS		25
+#define PMU_TDC0_AVG_NUM_MASK		(0x7 << PMU_TDC0_AVG_NUM_OFFS)
+
+/* Dove Thermal Diode Control 1 Register */
+#define PMU_TEMP_DIOD_CTRL1_REG		0x04
+#define PMU_TDC1_TEMP_VALID_MASK	(0x1 << 10)
+
+/* Dove Thermal Sensor Dev Structure */
+struct dove_thermal_priv {
+	void __iomem *sensor;
+	void __iomem *control;
+};
+
+static int dove_init_sensor(const struct dove_thermal_priv *priv)
+{
+	u32 reg;
+	u32 i;
+
+	/* Configure the Diode Control Register #0 */
+	reg = readl_relaxed(priv->control);
+
+	/* Use average of 2 */
+	reg &= ~PMU_TDC0_AVG_NUM_MASK;
+	reg |= (0x1 << PMU_TDC0_AVG_NUM_OFFS);
+
+	/* Reference calibration value */
+	reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
+	reg |= (0x0F1 << PMU_TDC0_REF_CAL_CNT_OFFS);
+
+	/* Set the high level reference for calibration */
+	reg &= ~PMU_TDC0_SEL_VCAL_MASK;
+	reg |= (0x2 << PMU_TDC0_SEL_VCAL_OFFS);
+	writel(reg, priv->control);
+
+	/* Reset the sensor */
+	reg = readl_relaxed(priv->control);
+	writel((reg | PMU_TDC0_SW_RST_MASK), priv->control);
+	writel(reg, priv->control);
+
+	/* Enable the sensor */
+	reg = readl_relaxed(priv->sensor);
+	reg &= ~PMU_TM_DISABLE_MASK;
+	writel(reg, priv->sensor);
+
+	/* Poll the sensor for the first reading */
+	for (i = 0; i < 1000000; i++) {
+		reg = readl_relaxed(priv->sensor);
+		if (reg & DOVE_THERMAL_TEMP_MASK)
+			break;
+	}
+
+	if (i == 1000000)
+		return -EIO;
+
+	return 0;
+}
+
+static int dove_get_temp(struct thermal_zone_device *thermal,
+			  unsigned long *temp)
+{
+	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");
+		return -EIO;
+	}
+
+	/*
+	 * Calculate temperature. See Section 8.10.1 of 88AP510,
+	 * Documentation/arm/Marvell/README
+	 */
+	reg = readl_relaxed(priv->sensor);
+	reg = (reg >> DOVE_THERMAL_TEMP_OFFSET) & DOVE_THERMAL_TEMP_MASK;
+	*temp = ((2281638UL - (7298*reg)) / 10);
+
+	return 0;
+}
+
+static struct thermal_zone_device_ops ops = {
+	.get_temp = dove_get_temp,
+};
+
+static const struct of_device_id dove_thermal_id_table[] = {
+	{ .compatible = "marvell,dove-thermal" },
+	{}
+};
+
+static int dove_thermal_probe(struct platform_device *pdev)
+{
+	struct thermal_zone_device *thermal = NULL;
+	struct dove_thermal_priv *priv;
+	struct resource *res;
+	int ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "Failed to get platform resource\n");
+		return -ENODEV;
+	}
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->sensor = devm_request_and_ioremap(&pdev->dev, res);
+	if (!priv->sensor) {
+		dev_err(&pdev->dev, "Failed to request_ioremap memory\n");
+		return -EADDRNOTAVAIL;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res) {
+		dev_err(&pdev->dev, "Failed to get platform resource\n");
+		return -ENODEV;
+	}
+	priv->control = devm_request_and_ioremap(&pdev->dev, res);
+	if (!priv->control) {
+		dev_err(&pdev->dev, "Failed to request_ioremap memory\n");
+		return -EADDRNOTAVAIL;
+	}
+
+	ret = dove_init_sensor(priv);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to initialize sensor\n");
+		return ret;
+	}
+
+	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");
+		return PTR_ERR(thermal);
+	}
+
+	platform_set_drvdata(pdev, thermal);
+
+	return 0;
+}
+
+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);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+MODULE_DEVICE_TABLE(of, dove_thermal_id_table);
+
+static struct platform_driver dove_thermal_driver = {
+	.probe = dove_thermal_probe,
+	.remove = dove_thermal_exit,
+	.driver = {
+		.name = "dove_thermal",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(dove_thermal_id_table),
+	},
+};
+
+module_platform_driver(dove_thermal_driver);
+
+MODULE_AUTHOR("Andrew Lunn <[e-mail]>");
+MODULE_DESCRIPTION("Dove thermal driver");
+MODULE_LICENSE("GPL");