hwmon: Add driver for EXYNOS4 TMU

This patch allows to read temperature
from TMU(Thermal Management Unit) of SAMSUNG EXYNOS4 series of SoC.

Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

3 files changed, 535 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 0b62c3c6b7c..c6fb7611dd1 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -303,6 +303,16 @@ config SENSORS_DS1621
 	  This driver can also be built as a module.  If so, the module
 	  will be called ds1621.
 
+config SENSORS_EXYNOS4_TMU
+	tristate "Temperature sensor on Samsung EXYNOS4"
+	depends on EXYNOS4_DEV_TMU
+	help
+	  If you say yes here you get support for TMU (Thermal Managment
+	  Unit) on SAMSUNG EXYNOS4 series of SoC.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called exynos4-tmu.
+
 config SENSORS_I5K_AMB
 	tristate "FB-DIMM AMB temperature sensor on Intel 5000 series chipsets"
 	depends on PCI && EXPERIMENTAL
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 3c9ccefea79..dbd8963ec7f 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_SENSORS_DS1621)	+= ds1621.o
 obj-$(CONFIG_SENSORS_EMC1403)	+= emc1403.o
 obj-$(CONFIG_SENSORS_EMC2103)	+= emc2103.o
 obj-$(CONFIG_SENSORS_EMC6W201)	+= emc6w201.o
+obj-$(CONFIG_SENSORS_EXYNOS4_TMU)	+= exynos4_tmu.o
 obj-$(CONFIG_SENSORS_F71805F)	+= f71805f.o
 obj-$(CONFIG_SENSORS_F71882FG)	+= f71882fg.o
 obj-$(CONFIG_SENSORS_F75375S)	+= f75375s.o
diff --git a/drivers/hwmon/exynos4_tmu.c b/drivers/hwmon/exynos4_tmu.c
new file mode 100644
index 00000000000..0170c90c635
--- /dev/null
+++ b/drivers/hwmon/exynos4_tmu.c
@@ -0,0 +1,524 @@
+/*
+ * exynos4_tmu.c - Samsung EXYNOS4 TMU (Thermal Management Unit)
+ *
+ *  Copyright (C) 2011 Samsung Electronics
+ *  Donggeun Kim <dg77.kim@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/workqueue.h>
+#include <linux/sysfs.h>
+#include <linux/kobject.h>
+#include <linux/io.h>
+#include <linux/mutex.h>
+
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+
+#include <linux/platform_data/exynos4_tmu.h>
+
+#define EXYNOS4_TMU_REG_TRIMINFO	0x0
+#define EXYNOS4_TMU_REG_CONTROL		0x20
+#define EXYNOS4_TMU_REG_STATUS		0x28
+#define EXYNOS4_TMU_REG_CURRENT_TEMP	0x40
+#define EXYNOS4_TMU_REG_THRESHOLD_TEMP	0x44
+#define EXYNOS4_TMU_REG_TRIG_LEVEL0	0x50
+#define EXYNOS4_TMU_REG_TRIG_LEVEL1	0x54
+#define EXYNOS4_TMU_REG_TRIG_LEVEL2	0x58
+#define EXYNOS4_TMU_REG_TRIG_LEVEL3	0x5C
+#define EXYNOS4_TMU_REG_PAST_TEMP0	0x60
+#define EXYNOS4_TMU_REG_PAST_TEMP1	0x64
+#define EXYNOS4_TMU_REG_PAST_TEMP2	0x68
+#define EXYNOS4_TMU_REG_PAST_TEMP3	0x6C
+#define EXYNOS4_TMU_REG_INTEN		0x70
+#define EXYNOS4_TMU_REG_INTSTAT		0x74
+#define EXYNOS4_TMU_REG_INTCLEAR	0x78
+
+#define EXYNOS4_TMU_GAIN_SHIFT		8
+#define EXYNOS4_TMU_REF_VOLTAGE_SHIFT	24
+
+#define EXYNOS4_TMU_TRIM_TEMP_MASK	0xff
+#define EXYNOS4_TMU_CORE_ON	3
+#define EXYNOS4_TMU_CORE_OFF	2
+#define EXYNOS4_TMU_DEF_CODE_TO_TEMP_OFFSET	50
+#define EXYNOS4_TMU_TRIG_LEVEL0_MASK	0x1
+#define EXYNOS4_TMU_TRIG_LEVEL1_MASK	0x10
+#define EXYNOS4_TMU_TRIG_LEVEL2_MASK	0x100
+#define EXYNOS4_TMU_TRIG_LEVEL3_MASK	0x1000
+#define EXYNOS4_TMU_INTCLEAR_VAL	0x1111
+
+struct exynos4_tmu_data {
+	struct exynos4_tmu_platform_data *pdata;
+	struct device *hwmon_dev;
+	struct resource *mem;
+	void __iomem *base;
+	int irq;
+	struct work_struct irq_work;
+	struct mutex lock;
+	struct clk *clk;
+	u8 temp_error1, temp_error2;
+};
+
+/*
+ * TMU treats temperature as a mapped temperature code.
+ * The temperature is converted differently depending on the calibration type.
+ */
+static int temp_to_code(struct exynos4_tmu_data *data, u8 temp)
+{
+	struct exynos4_tmu_platform_data *pdata = data->pdata;
+	int temp_code;
+
+	/* temp should range between 25 and 125 */
+	if (temp < 25 || temp > 125) {
+		temp_code = -EINVAL;
+		goto out;
+	}
+
+	switch (pdata->cal_type) {
+	case TYPE_TWO_POINT_TRIMMING:
+		temp_code = (temp - 25) *
+		    (data->temp_error2 - data->temp_error1) /
+		    (85 - 25) + data->temp_error1;
+		break;
+	case TYPE_ONE_POINT_TRIMMING:
+		temp_code = temp + data->temp_error1 - 25;
+		break;
+	default:
+		temp_code = temp + EXYNOS4_TMU_DEF_CODE_TO_TEMP_OFFSET;
+		break;
+	}
+out:
+	return temp_code;
+}
+
+/*
+ * Calculate a temperature value from a temperature code.
+ * The unit of the temperature is degree Celsius.
+ */
+static int code_to_temp(struct exynos4_tmu_data *data, u8 temp_code)
+{
+	struct exynos4_tmu_platform_data *pdata = data->pdata;
+	int temp;
+
+	/* temp_code should range between 75 and 175 */
+	if (temp_code < 75 || temp_code > 175) {
+		temp = -ENODATA;
+		goto out;
+	}
+
+	switch (pdata->cal_type) {
+	case TYPE_TWO_POINT_TRIMMING:
+		temp = (temp_code - data->temp_error1) * (85 - 25) /
+		    (data->temp_error2 - data->temp_error1) + 25;
+		break;
+	case TYPE_ONE_POINT_TRIMMING:
+		temp = temp_code - data->temp_error1 + 25;
+		break;
+	default:
+		temp = temp_code - EXYNOS4_TMU_DEF_CODE_TO_TEMP_OFFSET;
+		break;
+	}
+out:
+	return temp;
+}
+
+static int exynos4_tmu_initialize(struct platform_device *pdev)
+{
+	struct exynos4_tmu_data *data = platform_get_drvdata(pdev);
+	struct exynos4_tmu_platform_data *pdata = data->pdata;
+	unsigned int status, trim_info;
+	int ret = 0, threshold_code;
+
+	mutex_lock(&data->lock);
+	clk_enable(data->clk);
+
+	status = readb(data->base + EXYNOS4_TMU_REG_STATUS);
+	if (!status) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	/* Save trimming info in order to perform calibration */
+	trim_info = readl(data->base + EXYNOS4_TMU_REG_TRIMINFO);
+	data->temp_error1 = trim_info & EXYNOS4_TMU_TRIM_TEMP_MASK;
+	data->temp_error2 = ((trim_info >> 8) & EXYNOS4_TMU_TRIM_TEMP_MASK);
+
+	/* Write temperature code for threshold */
+	threshold_code = temp_to_code(data, pdata->threshold);
+	if (threshold_code < 0) {
+		ret = threshold_code;
+		goto out;
+	}
+	writeb(threshold_code,
+		data->base + EXYNOS4_TMU_REG_THRESHOLD_TEMP);
+
+	writeb(pdata->trigger_levels[0],
+		data->base + EXYNOS4_TMU_REG_TRIG_LEVEL0);
+	writeb(pdata->trigger_levels[1],
+		data->base + EXYNOS4_TMU_REG_TRIG_LEVEL1);
+	writeb(pdata->trigger_levels[2],
+		data->base + EXYNOS4_TMU_REG_TRIG_LEVEL2);
+	writeb(pdata->trigger_levels[3],
+		data->base + EXYNOS4_TMU_REG_TRIG_LEVEL3);
+
+	writel(EXYNOS4_TMU_INTCLEAR_VAL,
+		data->base + EXYNOS4_TMU_REG_INTCLEAR);
+out:
+	clk_disable(data->clk);
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+static void exynos4_tmu_control(struct platform_device *pdev, bool on)
+{
+	struct exynos4_tmu_data *data = platform_get_drvdata(pdev);
+	struct exynos4_tmu_platform_data *pdata = data->pdata;
+	unsigned int con, interrupt_en;
+
+	mutex_lock(&data->lock);
+	clk_enable(data->clk);
+
+	con = pdata->reference_voltage << EXYNOS4_TMU_REF_VOLTAGE_SHIFT |
+		pdata->gain << EXYNOS4_TMU_GAIN_SHIFT;
+	if (on) {
+		con |= EXYNOS4_TMU_CORE_ON;
+		interrupt_en = pdata->trigger_level3_en << 12 |
+			pdata->trigger_level2_en << 8 |
+			pdata->trigger_level1_en << 4 |
+			pdata->trigger_level0_en;
+	} else {
+		con |= EXYNOS4_TMU_CORE_OFF;
+		interrupt_en = 0; /* Disable all interrupts */
+	}
+	writel(interrupt_en, data->base + EXYNOS4_TMU_REG_INTEN);
+	writel(con, data->base + EXYNOS4_TMU_REG_CONTROL);
+
+	clk_disable(data->clk);
+	mutex_unlock(&data->lock);
+}
+
+static int exynos4_tmu_read(struct exynos4_tmu_data *data)
+{
+	u8 temp_code;
+	int temp;
+
+	mutex_lock(&data->lock);
+	clk_enable(data->clk);
+
+	temp_code = readb(data->base + EXYNOS4_TMU_REG_CURRENT_TEMP);
+	temp = code_to_temp(data, temp_code);
+
+	clk_disable(data->clk);
+	mutex_unlock(&data->lock);
+
+	return temp;
+}
+
+static void exynos4_tmu_work(struct work_struct *work)
+{
+	struct exynos4_tmu_data *data = container_of(work,
+			struct exynos4_tmu_data, irq_work);
+
+	mutex_lock(&data->lock);
+	clk_enable(data->clk);
+
+	writel(EXYNOS4_TMU_INTCLEAR_VAL, data->base + EXYNOS4_TMU_REG_INTCLEAR);
+
+	kobject_uevent(&data->hwmon_dev->kobj, KOBJ_CHANGE);
+
+	enable_irq(data->irq);
+
+	clk_disable(data->clk);
+	mutex_unlock(&data->lock);
+}
+
+static irqreturn_t exynos4_tmu_irq(int irq, void *id)
+{
+	struct exynos4_tmu_data *data = id;
+
+	disable_irq_nosync(irq);
+	schedule_work(&data->irq_work);
+
+	return IRQ_HANDLED;
+}
+
+static ssize_t exynos4_tmu_show_name(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "exynos4-tmu\n");
+}
+
+static ssize_t exynos4_tmu_show_temp(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct exynos4_tmu_data *data = dev_get_drvdata(dev);
+	int ret;
+
+	ret = exynos4_tmu_read(data);
+	if (ret < 0)
+		return ret;
+
+	/* convert from degree Celsius to millidegree Celsius */
+	return sprintf(buf, "%d\n", ret * 1000);
+}
+
+static ssize_t exynos4_tmu_show_alarm(struct device *dev,
+		struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct exynos4_tmu_data *data = dev_get_drvdata(dev);
+	struct exynos4_tmu_platform_data *pdata = data->pdata;
+	int temp;
+	unsigned int trigger_level;
+
+	temp = exynos4_tmu_read(data);
+	if (temp < 0)
+		return temp;
+
+	trigger_level = pdata->threshold + pdata->trigger_levels[attr->index];
+
+	return sprintf(buf, "%d\n", !!(temp > trigger_level));
+}
+
+static ssize_t exynos4_tmu_show_level(struct device *dev,
+		struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct exynos4_tmu_data *data = dev_get_drvdata(dev);
+	struct exynos4_tmu_platform_data *pdata = data->pdata;
+	unsigned int temp = pdata->threshold +
+			pdata->trigger_levels[attr->index];
+
+	return sprintf(buf, "%u\n", temp * 1000);
+}
+
+static DEVICE_ATTR(name, S_IRUGO, exynos4_tmu_show_name, NULL);
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, exynos4_tmu_show_temp, NULL, 0);
+
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO,
+		exynos4_tmu_show_alarm, NULL, 1);
+static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO,
+		exynos4_tmu_show_alarm, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp1_emergency_alarm, S_IRUGO,
+		exynos4_tmu_show_alarm, NULL, 3);
+
+static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, exynos4_tmu_show_level, NULL, 1);
+static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, exynos4_tmu_show_level, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp1_emergency, S_IRUGO,
+		exynos4_tmu_show_level, NULL, 3);
+
+static struct attribute *exynos4_tmu_attributes[] = {
+	&dev_attr_name.attr,
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit.dev_attr.attr,
+	&sensor_dev_attr_temp1_emergency.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group exynos4_tmu_attr_group = {
+	.attrs = exynos4_tmu_attributes,
+};
+
+static int __devinit exynos4_tmu_probe(struct platform_device *pdev)
+{
+	struct exynos4_tmu_data *data;
+	struct exynos4_tmu_platform_data *pdata = pdev->dev.platform_data;
+	int ret;
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "No platform init data supplied.\n");
+		return -ENODEV;
+	}
+
+	data = kzalloc(sizeof(struct exynos4_tmu_data), GFP_KERNEL);
+	if (!data) {
+		dev_err(&pdev->dev, "Failed to allocate driver structure\n");
+		return -ENOMEM;
+	}
+
+	data->irq = platform_get_irq(pdev, 0);
+	if (data->irq < 0) {
+		ret = data->irq;
+		dev_err(&pdev->dev, "Failed to get platform irq\n");
+		goto err_free;
+	}
+
+	INIT_WORK(&data->irq_work, exynos4_tmu_work);
+
+	data->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!data->mem) {
+		ret = -ENOENT;
+		dev_err(&pdev->dev, "Failed to get platform resource\n");
+		goto err_free;
+	}
+
+	data->mem = request_mem_region(data->mem->start,
+			resource_size(data->mem), pdev->name);
+	if (!data->mem) {
+		ret = -ENODEV;
+		dev_err(&pdev->dev, "Failed to request memory region\n");
+		goto err_free;
+	}
+
+	data->base = ioremap(data->mem->start, resource_size(data->mem));
+	if (!data->base) {
+		ret = -ENODEV;
+		dev_err(&pdev->dev, "Failed to ioremap memory\n");
+		goto err_mem_region;
+	}
+
+	ret = request_irq(data->irq, exynos4_tmu_irq,
+		IRQF_DISABLED | IRQF_TRIGGER_RISING,
+		"exynos4-tmu", data);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq: %d\n", data->irq);
+		goto err_io_remap;
+	}
+
+	data->clk = clk_get(NULL, "tmu_apbif");
+	if (IS_ERR(data->clk)) {
+		ret = PTR_ERR(data->clk);
+		dev_err(&pdev->dev, "Failed to get clock\n");
+		goto err_irq;
+	}
+
+	data->pdata = pdata;
+	platform_set_drvdata(pdev, data);
+	mutex_init(&data->lock);
+
+	ret = exynos4_tmu_initialize(pdev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to initialize TMU\n");
+		goto err_clk;
+	}
+
+	ret = sysfs_create_group(&pdev->dev.kobj, &exynos4_tmu_attr_group);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to create sysfs group\n");
+		goto err_clk;
+	}
+
+	data->hwmon_dev = hwmon_device_register(&pdev->dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		ret = PTR_ERR(data->hwmon_dev);
+		dev_err(&pdev->dev, "Failed to register hwmon device\n");
+		goto err_create_group;
+	}
+
+	exynos4_tmu_control(pdev, true);
+
+	return 0;
+
+err_create_group:
+	sysfs_remove_group(&pdev->dev.kobj, &exynos4_tmu_attr_group);
+err_clk:
+	platform_set_drvdata(pdev, NULL);
+	clk_put(data->clk);
+err_irq:
+	free_irq(data->irq, data);
+err_io_remap:
+	iounmap(data->base);
+err_mem_region:
+	release_mem_region(data->mem->start, resource_size(data->mem));
+err_free:
+	kfree(data);
+
+	return ret;
+}
+
+static int __devexit exynos4_tmu_remove(struct platform_device *pdev)
+{
+	struct exynos4_tmu_data *data = platform_get_drvdata(pdev);
+
+	exynos4_tmu_control(pdev, false);
+
+	hwmon_device_unregister(data->hwmon_dev);
+	sysfs_remove_group(&pdev->dev.kobj, &exynos4_tmu_attr_group);
+
+	clk_put(data->clk);
+
+	free_irq(data->irq, data);
+
+	iounmap(data->base);
+	release_mem_region(data->mem->start, resource_size(data->mem));
+
+	platform_set_drvdata(pdev, NULL);
+
+	kfree(data);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int exynos4_tmu_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	exynos4_tmu_control(pdev, false);
+
+	return 0;
+}
+
+static int exynos4_tmu_resume(struct platform_device *pdev)
+{
+	exynos4_tmu_initialize(pdev);
+	exynos4_tmu_control(pdev, true);
+
+	return 0;
+}
+#else
+#define exynos4_tmu_suspend NULL
+#define exynos4_tmu_resume NULL
+#endif
+
+static struct platform_driver exynos4_tmu_driver = {
+	.driver = {
+		.name   = "exynos4-tmu",
+		.owner  = THIS_MODULE,
+	},
+	.probe = exynos4_tmu_probe,
+	.remove	= __devexit_p(exynos4_tmu_remove),
+	.suspend = exynos4_tmu_suspend,
+	.resume = exynos4_tmu_resume,
+};
+
+static int __init exynos4_tmu_driver_init(void)
+{
+	return platform_driver_register(&exynos4_tmu_driver);
+}
+module_init(exynos4_tmu_driver_init);
+
+static void __exit exynos4_tmu_driver_exit(void)
+{
+	platform_driver_unregister(&exynos4_tmu_driver);
+}
+module_exit(exynos4_tmu_driver_exit);
+
+MODULE_DESCRIPTION("EXYNOS4 TMU Driver");
+MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:exynos4-tmu");