asus-wmi: add keyboard backlight support

Based on a patch from Nate Weibley. <nweibley@gmail.com>.

Cc: Nate Weibley <nweibley@gmail.com>
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

1 files changed, 113 insertions, 17 deletions

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index fa2b395145a..83a7a8101fd 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -66,6 +66,8 @@ MODULE_LICENSE("GPL");
 #define NOTIFY_BRNUP_MAX                0x1f
 #define NOTIFY_BRNDOWN_MIN              0x20
 #define NOTIFY_BRNDOWN_MAX              0x2e
+#define NOTIFY_KBD_BRTUP                0xc4
+#define NOTIFY_KBD_BRTDWN               0xc5
 
 /* WMI Methods */
 #define ASUS_WMI_METHODID_SPEC          0x43455053 /* BIOS SPECification */
@@ -174,8 +176,11 @@ struct asus_wmi {
 
         struct led_classdev tpd_led;
         int tpd_led_wk;
+        struct led_classdev kbd_led;
+        int kbd_led_wk;
         struct workqueue_struct *led_workqueue;
         struct work_struct tpd_led_work;
+        struct work_struct kbd_led_work;
 
         struct asus_rfkill wlan;
         struct asus_rfkill bluetooth;
@@ -360,30 +365,79 @@ static enum led_brightness tpd_led_get(struct led_classdev *led_cdev)
         return read_tpd_led_state(asus);
 }
 
-static int asus_wmi_led_init(struct asus_wmi *asus)
+static void kbd_led_update(struct work_struct *work)
 {
-        int rv;
+        int ctrl_param = 0;
+        struct asus_wmi *asus;
 
-        if (read_tpd_led_state(asus) < 0)
-                return 0;
+        asus = container_of(work, struct asus_wmi, kbd_led_work);
 
-        asus->led_workqueue = create_singlethread_workqueue("led_workqueue");
-        if (!asus->led_workqueue)
-                return -ENOMEM;
-        INIT_WORK(&asus->tpd_led_work, tpd_led_update);
+        /*
+         * bits 0-2: level
+         * bit 7: light on/off
+         */
+        if (asus->kbd_led_wk > 0)
+                ctrl_param = 0x80 | (asus->kbd_led_wk & 0x7F);
 
-        asus->tpd_led.name = "asus::touchpad";
-        asus->tpd_led.brightness_set = tpd_led_set;
-        asus->tpd_led.brightness_get = tpd_led_get;
-        asus->tpd_led.max_brightness = 1;
+        asus_wmi_set_devstate(ASUS_WMI_DEVID_KBD_BACKLIGHT, ctrl_param, NULL);
+}
 
-        rv = led_classdev_register(&asus->platform_device->dev, &asus->tpd_led);
-        if (rv) {
-                destroy_workqueue(asus->led_workqueue);
-                return rv;
+static int kbd_led_read(struct asus_wmi *asus, int *level, int *env)
+{
+        int retval;
+
+        /*
+         * bits 0-2: level
+         * bit 7: light on/off
+         * bit 8-10: environment (0: dark, 1: normal, 2: light)
+         * bit 17: status unknown
+         */
+        retval = asus_wmi_get_devstate_bits(asus, ASUS_WMI_DEVID_KBD_BACKLIGHT,
+                                            0xFFFF);
+
+        if (retval == 0x8000)
+                retval = -ENODEV;
+
+        if (retval >= 0) {
+                if (level)
+                        *level = retval & 0x80 ? retval & 0x7F : 0;
+                if (env)
+                        *env = (retval >> 8) & 0x7F;
+                retval = 0;
         }
 
-        return 0;
+        return retval;
+}
+
+static void kbd_led_set(struct led_classdev *led_cdev,
+                        enum led_brightness value)
+{
+        struct asus_wmi *asus;
+
+        asus = container_of(led_cdev, struct asus_wmi, kbd_led);
+
+        if (value > asus->kbd_led.max_brightness)
+                value = asus->kbd_led.max_brightness;
+        else if (value < 0)
+                value = 0;
+
+        asus->kbd_led_wk = value;
+        queue_work(asus->led_workqueue, &asus->kbd_led_work);
+}
+
+static enum led_brightness kbd_led_get(struct led_classdev *led_cdev)
+{
+        struct asus_wmi *asus;
+        int retval, value;
+
+        asus = container_of(led_cdev, struct asus_wmi, kbd_led);
+
+        retval = kbd_led_read(asus, &value, NULL);
+
+        if (retval < 0)
+                return retval;
+
+        return value;
 }
 
 static void asus_wmi_led_exit(struct asus_wmi *asus)
@@ -394,6 +448,48 @@ static void asus_wmi_led_exit(struct asus_wmi *asus)
                 destroy_workqueue(asus->led_workqueue);
 }
 
+static int asus_wmi_led_init(struct asus_wmi *asus)
+{
+        int rv = 0;
+
+        asus->led_workqueue = create_singlethread_workqueue("led_workqueue");
+        if (!asus->led_workqueue)
+                return -ENOMEM;
+
+        if (read_tpd_led_state(asus) >= 0) {
+                INIT_WORK(&asus->tpd_led_work, tpd_led_update);
+
+                asus->tpd_led.name = "asus::touchpad";
+                asus->tpd_led.brightness_set = tpd_led_set;
+                asus->tpd_led.brightness_get = tpd_led_get;
+                asus->tpd_led.max_brightness = 1;
+
+                rv = led_classdev_register(&asus->platform_device->dev,
+                                           &asus->tpd_led);
+                if (rv)
+                        goto error;
+        }
+
+        if (kbd_led_read(asus, NULL, NULL) >= 0) {
+                INIT_WORK(&asus->kbd_led_work, kbd_led_update);
+
+                asus->kbd_led.name = "asus::kbd_backlight";
+                asus->kbd_led.brightness_set = kbd_led_set;
+                asus->kbd_led.brightness_get = kbd_led_get;
+                asus->kbd_led.max_brightness = 3;
+
+                rv = led_classdev_register(&asus->platform_device->dev,
+                                           &asus->kbd_led);
+        }
+
+error:
+        if (rv)
+                asus_wmi_led_exit(asus);
+
+        return rv;
+}
+
+
 /*
  * PCI hotplug (for wlan rfkill)
  */