asus-wmi: add hwmon interface and pwm1

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

2 files changed, 129 insertions, 0 deletions

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 45f4d63c7939..0c7cf666a1bc 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -458,6 +458,7 @@ config ASUS_WMI
         tristate "ASUS WMI Driver (EXPERIMENTAL)"
         depends on ACPI_WMI
         depends on INPUT
+        depends on HWMON
         depends on EXPERIMENTAL
         depends on BACKLIGHT_CLASS_DEVICE
         depends on RFKILL || RFKILL = n
diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 05db6b2067b5..5b779a9443d6 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -39,6 +39,8 @@
 #include <linux/rfkill.h>
 #include <linux/pci.h>
 #include <linux/pci_hotplug.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 #include <linux/platform_device.h>
@@ -167,6 +169,7 @@ struct asus_wmi {
 
         struct input_dev *inputdev;
         struct backlight_device *backlight_device;
+        struct device *hwmon_device;
         struct platform_device *platform_device;
 
         struct led_classdev tpd_led;
@@ -791,6 +794,124 @@ exit:
 }
 
 /*
+ * Hwmon device
+ */
+static ssize_t asus_hwmon_pwm1(struct device *dev,
+                            struct device_attribute *attr,
+                            char *buf)
+{
+        struct asus_wmi *asus = dev_get_drvdata(dev);
+        u32 value;
+        int err;
+
+        err = asus_wmi_get_devstate(asus, ASUS_WMI_DEVID_FAN_CTRL, &value);
+
+        if (err < 0)
+                return err;
+
+        value |= 0xFF;
+
+        if (value == 1) /* Low Speed */
+                value = 85;
+        else if (value == 2)
+                value = 170;
+        else if (value == 3)
+                value = 255;
+        else if (value != 0) {
+                pr_err("Unknown fan speed %#x", value);
+                value = -1;
+        }
+
+        return sprintf(buf, "%d\n", value);
+}
+
+static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO, asus_hwmon_pwm1, NULL, 0);
+
+static ssize_t
+show_name(struct device *dev, struct device_attribute *attr, char *buf)
+{
+        return sprintf(buf, "asus\n");
+}
+static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, 0);
+
+static struct attribute *hwmon_attributes[] = {
+        &sensor_dev_attr_pwm1.dev_attr.attr,
+        &sensor_dev_attr_name.dev_attr.attr,
+        NULL
+};
+
+static mode_t asus_hwmon_sysfs_is_visible(struct kobject *kobj,
+                                    struct attribute *attr, int idx)
+{
+        struct device *dev = container_of(kobj, struct device, kobj);
+        struct platform_device *pdev = to_platform_device(dev->parent);
+        struct asus_wmi *asus = platform_get_drvdata(pdev);
+        bool ok = true;
+        int dev_id = -1;
+        u32 value = ASUS_WMI_UNSUPPORTED_METHOD;
+
+        if (attr == &sensor_dev_attr_pwm1.dev_attr.attr)
+                dev_id = ASUS_WMI_DEVID_FAN_CTRL;
+
+        if (dev_id != -1) {
+                int err = asus_wmi_get_devstate(asus, dev_id, &value);
+
+                if (err < 0)
+                        return err;
+        }
+
+        if (dev_id == ASUS_WMI_DEVID_FAN_CTRL) {
+                /*
+                 * We need to find a better way, probably using sfun,
+                 * bits or spec ...
+                 * Currently we disable it if:
+                 * - ASUS_WMI_UNSUPPORTED_METHOD is returned
+                 * - reverved bits are non-zero
+                 * - sfun and presence bit are not set
+                 */
+                if (value != ASUS_WMI_UNSUPPORTED_METHOD || value & 0xFFF80000
+                    || (!asus->sfun && !(value & ASUS_WMI_DSTS_PRESENCE_BIT)))
+                        ok = false;
+        }
+
+        return ok ? attr->mode : 0;
+}
+
+static struct attribute_group hwmon_attribute_group = {
+        .is_visible = asus_hwmon_sysfs_is_visible,
+        .attrs = hwmon_attributes
+};
+
+static void asus_wmi_hwmon_exit(struct asus_wmi *asus)
+{
+        struct device *hwmon;
+
+        hwmon = asus->hwmon_device;
+        if (!hwmon)
+                return;
+        sysfs_remove_group(&hwmon->kobj, &hwmon_attribute_group);
+        hwmon_device_unregister(hwmon);
+        asus->hwmon_device = NULL;
+}
+
+static int asus_wmi_hwmon_init(struct asus_wmi *asus)
+{
+        struct device *hwmon;
+        int result;
+
+        hwmon = hwmon_device_register(&asus->platform_device->dev);
+        if (IS_ERR(hwmon)) {
+                pr_err("Could not register asus hwmon device\n");
+                return PTR_ERR(hwmon);
+        }
+        asus->hwmon_device = hwmon;
+        result = sysfs_create_group(&hwmon->kobj, &hwmon_attribute_group);
+        if (result)
+                asus_wmi_hwmon_exit(asus);
+        return result;
+}
+
+/*
  * Backlight
  */
 static int read_backlight_power(struct asus_wmi *asus)
@@ -1331,6 +1452,10 @@ static int asus_wmi_add(struct platform_device *pdev)
         if (err)
                 goto fail_input;
 
+        err = asus_wmi_hwmon_init(asus);
+        if (err)
+                goto fail_hwmon;
+
         err = asus_wmi_led_init(asus);
         if (err)
                 goto fail_leds;
@@ -1369,6 +1494,8 @@ fail_backlight:
 fail_rfkill:
         asus_wmi_led_exit(asus);
 fail_leds:
+        asus_wmi_hwmon_exit(asus);
+fail_hwmon:
         asus_wmi_input_exit(asus);
 fail_input:
         asus_wmi_platform_exit(asus);
@@ -1385,6 +1512,7 @@ static int asus_wmi_remove(struct platform_device *device)
         wmi_remove_notify_handler(asus->driver->event_guid);
         asus_wmi_backlight_exit(asus);
         asus_wmi_input_exit(asus);
+        asus_wmi_hwmon_exit(asus);
         asus_wmi_led_exit(asus);
         asus_wmi_rfkill_exit(asus);
         asus_wmi_debugfs_exit(asus);