thermal: hisilicon: add new hisilicon thermal sensor driver

This patch adds the support for hisilicon thermal sensor, within
hisilicon SoC. there will register sensors for thermal framework
and use device tree to bind cooling device.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: kongxinwei <kong.kongxinwei@hisilicon.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

3 files changed, 430 insertions, 0 deletions

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 3379bee..80e9c45 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -161,6 +161,14 @@ config THERMAL_EMULATION
 	  because userland can easily disable the thermal policy by simply
 	  flooding this sysfs node with low temperature values.
 
+config HISI_THERMAL
+	tristate "Hisilicon thermal driver"
+	depends on ARCH_HISI && CPU_THERMAL && OF
+	help
+	  Enable this to plug hisilicon's thermal sensor driver into the Linux
+	  thermal framework. cpufreq is used as the cooling device to throttle
+	  CPUs when the passive trip is crossed.
+
 config IMX_THERMAL
 	tristate "Temperature sensor driver for Freescale i.MX SoCs"
 	depends on CPU_THERMAL
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index b1783cf..ff6422e 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -41,3 +41,4 @@ obj-$(CONFIG_TI_SOC_THERMAL)	+= ti-soc-thermal/
 obj-$(CONFIG_INT340X_THERMAL)  += int340x_thermal/
 obj-$(CONFIG_ST_THERMAL)	+= st/
 obj-$(CONFIG_TEGRA_SOCTHERM)	+= tegra_soctherm.o
+obj-$(CONFIG_HISI_THERMAL)     += hisi_thermal.o
diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
new file mode 100644
index 0000000..d5dd357
--- /dev/null
+++ b/drivers/thermal/hisi_thermal.c
@@ -0,0 +1,421 @@
+/*
+ * Hisilicon thermal sensor driver
+ *
+ * Copyright (c) 2014-2015 Hisilicon Limited.
+ * Copyright (c) 2014-2015 Linaro Limited.
+ *
+ * Xinwei Kong <kong.kongxinwei@hisilicon.com>
+ * Leo Yan <leo.yan@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+#include "thermal_core.h"
+
+#define TEMP0_TH			(0x4)
+#define TEMP0_RST_TH			(0x8)
+#define TEMP0_CFG			(0xC)
+#define TEMP0_EN			(0x10)
+#define TEMP0_INT_EN			(0x14)
+#define TEMP0_INT_CLR			(0x18)
+#define TEMP0_RST_MSK			(0x1C)
+#define TEMP0_VALUE			(0x28)
+
+#define HISI_TEMP_BASE			(-60)
+#define HISI_TEMP_RESET			(100000)
+
+#define HISI_MAX_SENSORS		4
+
+struct hisi_thermal_sensor {
+	struct hisi_thermal_data *thermal;
+	struct thermal_zone_device *tzd;
+
+	long sensor_temp;
+	uint32_t id;
+	uint32_t thres_temp;
+};
+
+struct hisi_thermal_data {
+	struct mutex thermal_lock;    /* protects register data */
+	struct platform_device *pdev;
+	struct clk *clk;
+	struct hisi_thermal_sensor sensors[HISI_MAX_SENSORS];
+
+	int irq, irq_bind_sensor;
+	bool irq_enabled;
+
+	void __iomem *regs;
+};
+
+/* in millicelsius */
+static inline int _step_to_temp(int step)
+{
+	/*
+	 * Every step equals (1 * 200) / 255 celsius, and finally
+	 * need convert to millicelsius.
+	 */
+	return (HISI_TEMP_BASE + (step * 200 / 255)) * 1000;
+}
+
+static inline long _temp_to_step(long temp)
+{
+	return ((temp / 1000 - HISI_TEMP_BASE) * 255 / 200);
+}
+
+static long hisi_thermal_get_sensor_temp(struct hisi_thermal_data *data,
+					 struct hisi_thermal_sensor *sensor)
+{
+	long val;
+
+	mutex_lock(&data->thermal_lock);
+
+	/* disable interrupt */
+	writel(0x0, data->regs + TEMP0_INT_EN);
+	writel(0x1, data->regs + TEMP0_INT_CLR);
+
+	/* disable module firstly */
+	writel(0x0, data->regs + TEMP0_EN);
+
+	/* select sensor id */
+	writel((sensor->id << 12), data->regs + TEMP0_CFG);
+
+	/* enable module */
+	writel(0x1, data->regs + TEMP0_EN);
+
+	usleep_range(3000, 5000);
+
+	val = readl(data->regs + TEMP0_VALUE);
+	val = _step_to_temp(val);
+
+	mutex_unlock(&data->thermal_lock);
+
+	return val;
+}
+
+static void hisi_thermal_enable_bind_irq_sensor
+			(struct hisi_thermal_data *data)
+{
+	struct hisi_thermal_sensor *sensor;
+
+	mutex_lock(&data->thermal_lock);
+
+	sensor = &data->sensors[data->irq_bind_sensor];
+
+	/* setting the hdak time */
+	writel(0x0, data->regs + TEMP0_CFG);
+
+	/* disable module firstly */
+	writel(0x0, data->regs + TEMP0_RST_MSK);
+	writel(0x0, data->regs + TEMP0_EN);
+
+	/* select sensor id */
+	writel((sensor->id << 12), data->regs + TEMP0_CFG);
+
+	/* enable for interrupt */
+	writel(_temp_to_step(sensor->thres_temp) | 0x0FFFFFF00,
+	       data->regs + TEMP0_TH);
+
+	writel(_temp_to_step(HISI_TEMP_RESET), data->regs + TEMP0_RST_TH);
+
+	/* enable module */
+	writel(0x1, data->regs + TEMP0_RST_MSK);
+	writel(0x1, data->regs + TEMP0_EN);
+
+	writel(0x0, data->regs + TEMP0_INT_CLR);
+	writel(0x1, data->regs + TEMP0_INT_EN);
+
+	usleep_range(3000, 5000);
+
+	mutex_unlock(&data->thermal_lock);
+}
+
+static void hisi_thermal_disable_sensor(struct hisi_thermal_data *data)
+{
+	mutex_lock(&data->thermal_lock);
+
+	/* disable sensor module */
+	writel(0x0, data->regs + TEMP0_INT_EN);
+	writel(0x0, data->regs + TEMP0_RST_MSK);
+	writel(0x0, data->regs + TEMP0_EN);
+
+	mutex_unlock(&data->thermal_lock);
+}
+
+static int hisi_thermal_get_temp(void *_sensor, long *temp)
+{
+	struct hisi_thermal_sensor *sensor = _sensor;
+	struct hisi_thermal_data *data = sensor->thermal;
+
+	int sensor_id = 0, i;
+	long max_temp = 0;
+
+	*temp = hisi_thermal_get_sensor_temp(data, sensor);
+
+	sensor->sensor_temp = *temp;
+
+	for (i = 0; i < HISI_MAX_SENSORS; i++) {
+		if (data->sensors[i].sensor_temp >= max_temp) {
+			max_temp = data->sensors[i].sensor_temp;
+			sensor_id = i;
+		}
+	}
+
+	mutex_lock(&data->thermal_lock);
+	data->irq_bind_sensor = sensor_id;
+	mutex_unlock(&data->thermal_lock);
+
+	dev_dbg(&data->pdev->dev, "id=%d, irq=%d, temp=%ld, thres=%d\n",
+		sensor->id, data->irq_enabled, *temp, sensor->thres_temp);
+	/*
+	 * Bind irq to sensor for two cases:
+	 *   Reenable alarm IRQ if temperature below threshold;
+	 *   if irq has been enabled, always set it;
+	 */
+	if (data->irq_enabled) {
+		hisi_thermal_enable_bind_irq_sensor(data);
+		return 0;
+	}
+
+	if (max_temp < sensor->thres_temp) {
+		data->irq_enabled = true;
+		hisi_thermal_enable_bind_irq_sensor(data);
+		enable_irq(data->irq);
+	}
+
+	return 0;
+}
+
+static struct thermal_zone_of_device_ops hisi_of_thermal_ops = {
+	.get_temp = hisi_thermal_get_temp,
+};
+
+static irqreturn_t hisi_thermal_alarm_irq(int irq, void *dev)
+{
+	struct hisi_thermal_data *data = dev;
+
+	disable_irq_nosync(irq);
+	data->irq_enabled = false;
+
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)
+{
+	struct hisi_thermal_data *data = dev;
+	struct hisi_thermal_sensor *sensor;
+	int i;
+
+	mutex_lock(&data->thermal_lock);
+	sensor = &data->sensors[data->irq_bind_sensor];
+
+	dev_crit(&data->pdev->dev, "THERMAL ALARM: T > %d\n",
+		 sensor->thres_temp / 1000);
+	mutex_unlock(&data->thermal_lock);
+
+	for (i = 0; i < HISI_MAX_SENSORS; i++)
+		thermal_zone_device_update(data->sensors[i].tzd);
+
+	return IRQ_HANDLED;
+}
+
+static int hisi_thermal_register_sensor(struct platform_device *pdev,
+					struct hisi_thermal_data *data,
+					struct hisi_thermal_sensor *sensor,
+					int index)
+{
+	int ret, i;
+	const struct thermal_trip *trip;
+
+	sensor->id = index;
+	sensor->thermal = data;
+
+	sensor->tzd = thermal_zone_of_sensor_register(&pdev->dev, sensor->id,
+				sensor, &hisi_of_thermal_ops);
+	if (IS_ERR(sensor->tzd)) {
+		ret = PTR_ERR(sensor->tzd);
+		dev_err(&pdev->dev, "failed to register sensor id %d: %d\n",
+			sensor->id, ret);
+		return ret;
+	}
+
+	trip = of_thermal_get_trip_points(sensor->tzd);
+
+	for (i = 0; i < of_thermal_get_ntrips(sensor->tzd); i++) {
+		if (trip[i].type == THERMAL_TRIP_PASSIVE) {
+			sensor->thres_temp = trip[i].temperature;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static const struct of_device_id of_hisi_thermal_match[] = {
+	{ .compatible = "hisilicon,tsensor" },
+	{ /* end */ }
+};
+MODULE_DEVICE_TABLE(of, of_hisi_thermal_match);
+
+static void hisi_thermal_toggle_sensor(struct hisi_thermal_sensor *sensor,
+				       bool on)
+{
+	struct thermal_zone_device *tzd = sensor->tzd;
+
+	tzd->ops->set_mode(tzd,
+		on ? THERMAL_DEVICE_ENABLED : THERMAL_DEVICE_DISABLED);
+}
+
+static int hisi_thermal_probe(struct platform_device *pdev)
+{
+	struct hisi_thermal_data *data;
+	struct resource *res;
+	int i;
+	int ret;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	mutex_init(&data->thermal_lock);
+	data->pdev = pdev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	data->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(data->regs)) {
+		dev_err(&pdev->dev, "failed to get io address\n");
+		return PTR_ERR(data->regs);
+	}
+
+	data->irq = platform_get_irq(pdev, 0);
+	if (data->irq < 0)
+		return data->irq;
+
+	ret = devm_request_threaded_irq(&pdev->dev, data->irq,
+					hisi_thermal_alarm_irq,
+					hisi_thermal_alarm_irq_thread,
+					0, "hisi_thermal", data);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, data);
+
+	data->clk = devm_clk_get(&pdev->dev, "thermal_clk");
+	if (IS_ERR(data->clk)) {
+		ret = PTR_ERR(data->clk);
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev,
+				"failed to get thermal clk: %d\n", ret);
+		return ret;
+	}
+
+	/* enable clock for thermal */
+	ret = clk_prepare_enable(data->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
+		return ret;
+	}
+
+	for (i = 0; i < HISI_MAX_SENSORS; ++i) {
+		ret = hisi_thermal_register_sensor(pdev, data,
+						   &data->sensors[i], i);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"failed to register thermal sensor: %d\n", ret);
+			goto err_get_sensor_data;
+		}
+	}
+
+	hisi_thermal_enable_bind_irq_sensor(data);
+	data->irq_enabled = true;
+
+	for (i = 0; i < HISI_MAX_SENSORS; i++)
+		hisi_thermal_toggle_sensor(&data->sensors[i], true);
+
+	return 0;
+
+err_get_sensor_data:
+	clk_disable_unprepare(data->clk);
+
+	return ret;
+}
+
+static int hisi_thermal_remove(struct platform_device *pdev)
+{
+	struct hisi_thermal_data *data = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = 0; i < HISI_MAX_SENSORS; i++) {
+		struct hisi_thermal_sensor *sensor = &data->sensors[i];
+
+		hisi_thermal_toggle_sensor(sensor, false);
+		thermal_zone_of_sensor_unregister(&pdev->dev, sensor->tzd);
+	}
+
+	hisi_thermal_disable_sensor(data);
+	clk_disable_unprepare(data->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int hisi_thermal_suspend(struct device *dev)
+{
+	struct hisi_thermal_data *data = dev_get_drvdata(dev);
+
+	hisi_thermal_disable_sensor(data);
+	data->irq_enabled = false;
+
+	clk_disable_unprepare(data->clk);
+
+	return 0;
+}
+
+static int hisi_thermal_resume(struct device *dev)
+{
+	struct hisi_thermal_data *data = dev_get_drvdata(dev);
+
+	clk_prepare_enable(data->clk);
+
+	data->irq_enabled = true;
+	hisi_thermal_enable_bind_irq_sensor(data);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(hisi_thermal_pm_ops,
+			 hisi_thermal_suspend, hisi_thermal_resume);
+
+static struct platform_driver hisi_thermal_driver = {
+	.driver = {
+		.name		= "hisi_thermal",
+		.owner		= THIS_MODULE,
+		.pm		= &hisi_thermal_pm_ops,
+		.of_match_table = of_hisi_thermal_match,
+	},
+	.probe	= hisi_thermal_probe,
+	.remove	= hisi_thermal_remove,
+};
+
+module_platform_driver(hisi_thermal_driver);
+
+MODULE_AUTHOR("Xinwei Kong <kong.kongxinwei@hisilicon.com>");
+MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
+MODULE_DESCRIPTION("Hisilicon thermal driver");
+MODULE_LICENSE("GPL v2");