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>

1 files changed, 524 insertions, 0 deletions

diff --git a/drivers/hwmon/exynos4_tmu.c b/drivers/hwmon/exynos4_tmu.c
new file mode 100644
index 000000000000..0170c90c635e
--- /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");