eeepc-laptop: add hwmon fan control

Adds an hwmon interface to control the fan.

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 148 insertions, 0 deletions

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 01b7deba91e8..7a4869a9db86 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -356,6 +356,7 @@ config EEEPC_LAPTOP
         depends on X86
         depends on ACPI
         depends on BACKLIGHT_CLASS_DEVICE
+        depends on HWMON
         depends on EXPERIMENTAL
         ---help---
           This driver supports the Fn-Fx keys on Eee PC laptops.
diff --git a/drivers/misc/eeepc-laptop.c b/drivers/misc/eeepc-laptop.c
index 2b59b7ed4b14..6d727609097f 100644
--- a/drivers/misc/eeepc-laptop.c
+++ b/drivers/misc/eeepc-laptop.c
@@ -23,6 +23,8 @@
 #include <linux/platform_device.h>
 #include <linux/backlight.h>
 #include <linux/fb.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
 #include <acpi/acpi_drivers.h>
 #include <acpi/acpi_bus.h>
 #include <linux/uaccess.h>
@@ -103,6 +105,15 @@ const char *cm_setv[] = {
         "CRDS", NULL
 };
 
+#define EEEPC_EC        "\\_SB.PCI0.SBRG.EC0."
+
+#define EEEPC_EC_FAN_PWM        EEEPC_EC "SC02" /* Fan PWM duty cycle (%) */
+#define EEEPC_EC_SC02           0x63
+#define EEEPC_EC_FAN_HRPM       EEEPC_EC "SC05" /* High byte, fan speed (RPM) */
+#define EEEPC_EC_FAN_LRPM       EEEPC_EC "SC06" /* Low byte, fan speed (RPM) */
+#define EEEPC_EC_FAN_CTRL       EEEPC_EC "SFB3" /* Byte containing SF25  */
+#define EEEPC_EC_SFB3           0xD3
+
 /*
  * This is the main structure, we can use it to store useful information
  * about the hotk device
@@ -154,6 +165,9 @@ static struct acpi_driver eeepc_hotk_driver = {
 /* The backlight device /sys/class/backlight */
 static struct backlight_device *eeepc_backlight_device;
 
+/* The hwmon device */
+static struct device *eeepc_hwmon_device;
+
 /*
  * The backlight class declaration
  */
@@ -429,6 +443,100 @@ static int eeepc_hotk_remove(struct acpi_device *device, int type)
 }
 
 /*
+ * Hwmon
+ */
+static int eeepc_get_fan_pwm(void)
+{
+        int value = 0;
+
+        read_acpi_int(NULL, EEEPC_EC_FAN_PWM, &value);
+        return (value);
+}
+
+static void eeepc_set_fan_pwm(int value)
+{
+        value = SENSORS_LIMIT(value, 0, 100);
+        ec_write(EEEPC_EC_SC02, value);
+}
+
+static int eeepc_get_fan_rpm(void)
+{
+        int high = 0;
+        int low = 0;
+
+        read_acpi_int(NULL, EEEPC_EC_FAN_HRPM, &high);
+        read_acpi_int(NULL, EEEPC_EC_FAN_LRPM, &low);
+        return (high << 8 | low);
+}
+
+static int eeepc_get_fan_ctrl(void)
+{
+        int value = 0;
+
+        read_acpi_int(NULL, EEEPC_EC_FAN_CTRL, &value);
+        return ((value & 0x02 ? 1 : 0));
+}
+
+static void eeepc_set_fan_ctrl(int manual)
+{
+        int value = 0;
+
+        read_acpi_int(NULL, EEEPC_EC_FAN_CTRL, &value);
+        if (manual)
+                value |= 0x02;
+        else
+                value &= ~0x02;
+        ec_write(EEEPC_EC_SFB3, value);
+}
+
+static ssize_t store_sys_hwmon(void (*set)(int), const char *buf, size_t count)
+{
+        int rv, value;
+
+        rv = parse_arg(buf, count, &value);
+        if (rv > 0)
+                set(value);
+        return rv;
+}
+
+static ssize_t show_sys_hwmon(int (*get)(void), char *buf)
+{
+        return sprintf(buf, "%d\n", get());
+}
+
+#define EEEPC_CREATE_SENSOR_ATTR(_name, _mode, _set, _get)              \
+        static ssize_t show_##_name(struct device *dev,                 \
+                                    struct device_attribute *attr,      \
+                                    char *buf)                          \
+        {                                                               \
+                return show_sys_hwmon(_set, buf);                       \
+        }                                                               \
+        static ssize_t store_##_name(struct device *dev,                \
+                                     struct device_attribute *attr,     \
+                                     const char *buf, size_t count)     \
+        {                                                               \
+                return store_sys_hwmon(_get, buf, count);               \
+        }                                                               \
+        static SENSOR_DEVICE_ATTR(_name, _mode, show_##_name, store_##_name, 0);
+
+EEEPC_CREATE_SENSOR_ATTR(fan1_input, S_IRUGO, eeepc_get_fan_rpm, NULL);
+EEEPC_CREATE_SENSOR_ATTR(fan1_pwm, S_IRUGO | S_IWUSR,
+                         eeepc_get_fan_pwm, eeepc_set_fan_pwm);
+EEEPC_CREATE_SENSOR_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
+                         eeepc_get_fan_ctrl, eeepc_set_fan_ctrl);
+
+static struct attribute *hwmon_attributes[] = {
+        &sensor_dev_attr_fan1_pwm.dev_attr.attr,
+        &sensor_dev_attr_fan1_input.dev_attr.attr,
+        &sensor_dev_attr_pwm1_enable.dev_attr.attr,
+        NULL
+};
+
+static struct attribute_group hwmon_attribute_group = {
+        .attrs = hwmon_attributes
+};
+
+/*
  * exit/init
  */
 static void eeepc_backlight_exit(void)
@@ -438,9 +546,23 @@ static void eeepc_backlight_exit(void)
         eeepc_backlight_device = NULL;
 }
 
+static void eeepc_hwmon_exit(void)
+{
+        struct device *hwmon;
+
+        hwmon = eeepc_hwmon_device;
+        if (!hwmon)
+                return ;
+        hwmon_device_unregister(hwmon);
+        sysfs_remove_group(&hwmon->kobj,
+                           &hwmon_attribute_group);
+        eeepc_hwmon_device = NULL;
+}
+
 static void __exit eeepc_laptop_exit(void)
 {
         eeepc_backlight_exit();
+        eeepc_hwmon_exit();
         acpi_bus_unregister_driver(&eeepc_hotk_driver);
         sysfs_remove_group(&platform_device->dev.kobj,
                            &platform_attribute_group);
@@ -468,6 +590,26 @@ static int eeepc_backlight_init(struct device *dev)
         return 0;
 }
 
+static int eeepc_hwmon_init(struct device *dev)
+{
+        struct device *hwmon;
+        int result;
+
+        hwmon = hwmon_device_register(dev);
+        if (IS_ERR(hwmon)) {
+                printk(EEEPC_ERR
+                       "Could not register eeepc hwmon device\n");
+                eeepc_hwmon_device = NULL;
+                return PTR_ERR(hwmon);
+        }
+        eeepc_hwmon_device = hwmon;
+        result = sysfs_create_group(&hwmon->kobj,
+                                    &hwmon_attribute_group);
+        if (result)
+                eeepc_hwmon_exit();
+        return result;
+}
+
 static int __init eeepc_laptop_init(void)
 {
         struct device *dev;
@@ -486,6 +628,9 @@ static int __init eeepc_laptop_init(void)
         result = eeepc_backlight_init(dev);
         if (result)
                 goto fail_backlight;
+        result = eeepc_hwmon_init(dev);
+        if (result)
+                goto fail_hwmon;
         /* Register platform stuff */
         result = platform_driver_register(&platform_driver);
         if (result)
@@ -510,6 +655,8 @@ fail_platform_device2:
 fail_platform_device1:
         platform_driver_unregister(&platform_driver);
 fail_platform_driver:
+        eeepc_hwmon_exit();
+fail_hwmon:
         eeepc_backlight_exit();
 fail_backlight:
         return result;