Thermal: exynos: Add sysfs node supporting exynos's emulation mode.

This patch supports exynos's emulation mode with newly created sysfs node.
Exynos 4x12 (4212, 4412) and 5 series provide emulation mode for thermal
management unit. Thermal emulation mode supports software debug for TMU's
operation. User can set temperature manually with software code and TMU
will read current temperature from user value not from sensor's value.
This patch includes also documentary placed under Documentation/thermal/.

Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

2 files changed, 112 insertions, 0 deletions

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index c2c77d1ac499..c31b9e4451a3 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -101,6 +101,15 @@ config EXYNOS_THERMAL
           If you say yes here you get support for TMU (Thermal Management
           Unit) on SAMSUNG EXYNOS series of SoC.
 
+config EXYNOS_THERMAL_EMUL
+        bool "EXYNOS TMU emulation mode support"
+        depends on EXYNOS_THERMAL
+        help
+          Exynos 4412 and 4414 and 5 series has emulation mode on TMU.
+          Enable this option will be make sysfs node in exynos thermal platform
+          device directory to support emulation mode. With emulation mode sysfs
+          node, you can manually input temperature to TMU for simulation purpose.
+
 config DB8500_THERMAL
         bool "DB8500 thermal management"
         depends on ARCH_U8500
diff --git a/drivers/thermal/exynos_thermal.c b/drivers/thermal/exynos_thermal.c
index 7772d1603769..e2ef8a3531ac 100644
--- a/drivers/thermal/exynos_thermal.c
+++ b/drivers/thermal/exynos_thermal.c
@@ -99,6 +99,14 @@
 #define IDLE_INTERVAL 10000
 #define MCELSIUS        1000
 
+#ifdef CONFIG_EXYNOS_THERMAL_EMUL
+#define EXYNOS_EMUL_TIME        0x57F0
+#define EXYNOS_EMUL_TIME_SHIFT  16
+#define EXYNOS_EMUL_DATA_SHIFT  8
+#define EXYNOS_EMUL_DATA_MASK   0xFF
+#define EXYNOS_EMUL_ENABLE      0x1
+#endif /* CONFIG_EXYNOS_THERMAL_EMUL */
+
 /* CPU Zone information */
 #define PANIC_ZONE      4
 #define WARN_ZONE       3
@@ -832,6 +840,94 @@ static inline struct  exynos_tmu_platform_data *exynos_get_driver_data(
         return (struct exynos_tmu_platform_data *)
                         platform_get_device_id(pdev)->driver_data;
 }
+
+#ifdef CONFIG_EXYNOS_THERMAL_EMUL
+static ssize_t exynos_tmu_emulation_show(struct device *dev,
+                                         struct device_attribute *attr,
+                                         char *buf)
+{
+        struct platform_device *pdev = container_of(dev,
+                                        struct platform_device, dev);
+        struct exynos_tmu_data *data = platform_get_drvdata(pdev);
+        unsigned int reg;
+        u8 temp_code;
+        int temp = 0;
+
+        if (data->soc == SOC_ARCH_EXYNOS4210)
+                goto out;
+
+        mutex_lock(&data->lock);
+        clk_enable(data->clk);
+        reg = readl(data->base + EXYNOS_EMUL_CON);
+        clk_disable(data->clk);
+        mutex_unlock(&data->lock);
+
+        if (reg & EXYNOS_EMUL_ENABLE) {
+                reg >>= EXYNOS_EMUL_DATA_SHIFT;
+                temp_code = reg & EXYNOS_EMUL_DATA_MASK;
+                temp = code_to_temp(data, temp_code);
+        }
+out:
+        return sprintf(buf, "%d\n", temp * MCELSIUS);
+}
+
+static ssize_t exynos_tmu_emulation_store(struct device *dev,
+                                        struct device_attribute *attr,
+                                        const char *buf, size_t count)
+{
+        struct platform_device *pdev = container_of(dev,
+                                        struct platform_device, dev);
+        struct exynos_tmu_data *data = platform_get_drvdata(pdev);
+        unsigned int reg;
+        int temp;
+
+        if (data->soc == SOC_ARCH_EXYNOS4210)
+                goto out;
+
+        if (!sscanf(buf, "%d\n", &temp) || temp < 0)
+                return -EINVAL;
+
+        mutex_lock(&data->lock);
+        clk_enable(data->clk);
+
+        reg = readl(data->base + EXYNOS_EMUL_CON);
+
+        if (temp) {
+                /* Both CELSIUS and MCELSIUS type are available for input */
+                if (temp > MCELSIUS)
+                        temp /= MCELSIUS;
+
+                reg = (EXYNOS_EMUL_TIME << EXYNOS_EMUL_TIME_SHIFT) |
+                        (temp_to_code(data, (temp / MCELSIUS))
+                         << EXYNOS_EMUL_DATA_SHIFT) | EXYNOS_EMUL_ENABLE;
+        } else {
+                reg &= ~EXYNOS_EMUL_ENABLE;
+        }
+
+        writel(reg, data->base + EXYNOS_EMUL_CON);
+
+        clk_disable(data->clk);
+        mutex_unlock(&data->lock);
+
+out:
+        return count;
+}
+
+static DEVICE_ATTR(emulation, 0644, exynos_tmu_emulation_show,
+                                        exynos_tmu_emulation_store);
+static int create_emulation_sysfs(struct device *dev)
+{
+        return device_create_file(dev, &dev_attr_emulation);
+}
+static void remove_emulation_sysfs(struct device *dev)
+{
+        device_remove_file(dev, &dev_attr_emulation);
+}
+#else
+static inline int create_emulation_sysfs(struct device *dev) { return 0; }
+static inline void remove_emulation_sysfs(struct device *dev) {}
+#endif
+
 static int __devinit exynos_tmu_probe(struct platform_device *pdev)
 {
         struct exynos_tmu_data *data;
@@ -930,6 +1026,11 @@ static int __devinit exynos_tmu_probe(struct platform_device *pdev)
                 dev_err(&pdev->dev, "Failed to register thermal interface\n");
                 goto err_clk;
         }
+
+        ret = create_emulation_sysfs(&pdev->dev);
+        if (ret)
+                dev_err(&pdev->dev, "Failed to create emulation mode sysfs node\n");
+
         return 0;
 err_clk:
         platform_set_drvdata(pdev, NULL);
@@ -941,6 +1042,8 @@ static int __devexit exynos_tmu_remove(struct platform_device *pdev)
 {
         struct exynos_tmu_data *data = platform_get_drvdata(pdev);
 
+        remove_emulation_sysfs(&pdev->dev);
+
         exynos_tmu_control(pdev, false);
 
         exynos_unregister_thermal();