ideapad: add backlight driver

When acpi_backlight=vendor in cmdline or no backlight support in acpi video
device, ideapad-laptop will register backlight device and control brightness
and backlight power via the command in VPC2004.

Signed-off-by: Ike Panhc <ike.pan@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

1 files changed, 117 insertions, 6 deletions

diff --git a/drivers/platform/x86/ideapad-laptop.c b/drivers/platform/x86/ideapad-laptop.c
index 1612abde5188..8811c68f809d 100644
--- a/drivers/platform/x86/ideapad-laptop.c
+++ b/drivers/platform/x86/ideapad-laptop.c
@@ -32,6 +32,8 @@
 #include <linux/platform_device.h>
 #include <linux/input.h>
 #include <linux/input/sparse-keymap.h>
+#include <linux/backlight.h>
+#include <linux/fb.h>
 
 #define IDEAPAD_RFKILL_DEV_NUM  (3)
 
@@ -44,6 +46,7 @@ struct ideapad_private {
         struct rfkill *rfk[IDEAPAD_RFKILL_DEV_NUM];
         struct platform_device *platform_device;
         struct input_dev *inputdev;
+        struct backlight_device *blightdev;
         unsigned long cfg;
 };
 
@@ -309,8 +312,7 @@ static int __devinit ideapad_register_rfkill(struct acpi_device *adevice,
         return 0;
 }
 
-static void __devexit ideapad_unregister_rfkill(struct acpi_device *adevice,
-                                                int dev)
+static void ideapad_unregister_rfkill(struct acpi_device *adevice, int dev)
 {
         struct ideapad_private *priv = dev_get_drvdata(&adevice->dev);
 
@@ -418,6 +420,98 @@ static void ideapad_input_report(struct ideapad_private *priv,
 }
 
 /*
+ * backlight
+ */
+static int ideapad_backlight_get_brightness(struct backlight_device *blightdev)
+{
+        unsigned long now;
+
+        if (read_ec_data(ideapad_handle, 0x12, &now))
+                return -EIO;
+        return now;
+}
+
+static int ideapad_backlight_update_status(struct backlight_device *blightdev)
+{
+        if (write_ec_cmd(ideapad_handle, 0x13, blightdev->props.brightness))
+                return -EIO;
+        if (write_ec_cmd(ideapad_handle, 0x33,
+                         blightdev->props.power == FB_BLANK_POWERDOWN ? 0 : 1))
+                return -EIO;
+
+        return 0;
+}
+
+static const struct backlight_ops ideapad_backlight_ops = {
+        .get_brightness = ideapad_backlight_get_brightness,
+        .update_status = ideapad_backlight_update_status,
+};
+
+static int ideapad_backlight_init(struct ideapad_private *priv)
+{
+        struct backlight_device *blightdev;
+        struct backlight_properties props;
+        unsigned long max, now, power;
+
+        if (read_ec_data(ideapad_handle, 0x11, &max))
+                return -EIO;
+        if (read_ec_data(ideapad_handle, 0x12, &now))
+                return -EIO;
+        if (read_ec_data(ideapad_handle, 0x18, &power))
+                return -EIO;
+
+        memset(&props, 0, sizeof(struct backlight_properties));
+        props.max_brightness = max;
+        props.type = BACKLIGHT_PLATFORM;
+        blightdev = backlight_device_register("ideapad",
+                                              &priv->platform_device->dev,
+                                              priv,
+                                              &ideapad_backlight_ops,
+                                              &props);
+        if (IS_ERR(blightdev)) {
+                pr_err("Could not register backlight device\n");
+                return PTR_ERR(blightdev);
+        }
+
+        priv->blightdev = blightdev;
+        blightdev->props.brightness = now;
+        blightdev->props.power = power ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
+        backlight_update_status(blightdev);
+
+        return 0;
+}
+
+static void ideapad_backlight_exit(struct ideapad_private *priv)
+{
+        if (priv->blightdev)
+                backlight_device_unregister(priv->blightdev);
+        priv->blightdev = NULL;
+}
+
+static void ideapad_backlight_notify_power(struct ideapad_private *priv)
+{
+        unsigned long power;
+        struct backlight_device *blightdev = priv->blightdev;
+
+        if (read_ec_data(ideapad_handle, 0x18, &power))
+                return;
+        blightdev->props.power = power ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
+}
+
+static void ideapad_backlight_notify_brightness(struct ideapad_private *priv)
+{
+        unsigned long now;
+
+        /* if we control brightness via acpi video driver */
+        if (priv->blightdev == NULL) {
+                read_ec_data(ideapad_handle, 0x12, &now);
+                return;
+        }
+
+        backlight_force_update(priv->blightdev, BACKLIGHT_UPDATE_HOTKEY);
+}
+
+/*
  * module init/exit
  */
 static const struct acpi_device_id ideapad_device_ids[] = {
@@ -458,8 +552,17 @@ static int __devinit ideapad_acpi_add(struct acpi_device *adevice)
         }
         ideapad_sync_rfk_state(adevice);
 
+        if (!acpi_video_backlight_support()) {
+                ret = ideapad_backlight_init(priv);
+                if (ret && ret != -ENODEV)
+                        goto backlight_failed;
+        }
+
         return 0;
 
+backlight_failed:
+        for (i = 0; i < IDEAPAD_RFKILL_DEV_NUM; i++)
+                ideapad_unregister_rfkill(adevice, i);
 input_failed:
         ideapad_platform_exit(priv);
 platform_failed:
@@ -472,6 +575,7 @@ static int __devexit ideapad_acpi_remove(struct acpi_device *adevice, int type)
         struct ideapad_private *priv = dev_get_drvdata(&adevice->dev);
         int i;
 
+        ideapad_backlight_exit(priv);
         for (i = 0; i < IDEAPAD_RFKILL_DEV_NUM; i++)
                 ideapad_unregister_rfkill(adevice, i);
         ideapad_input_exit(priv);
@@ -496,12 +600,19 @@ static void ideapad_acpi_notify(struct acpi_device *adevice, u32 event)
         vpc1 = (vpc2 << 8) | vpc1;
         for (vpc_bit = 0; vpc_bit < 16; vpc_bit++) {
                 if (test_bit(vpc_bit, &vpc1)) {
-                        if (vpc_bit == 9)
+                        switch (vpc_bit) {
+                        case 9:
                                 ideapad_sync_rfk_state(adevice);
-                        else if (vpc_bit == 4)
-                                read_ec_data(handle, 0x12, &vpc2);
-                        else
+                                break;
+                        case 4:
+                                ideapad_backlight_notify_brightness(priv);
+                                break;
+                        case 2:
+                                ideapad_backlight_notify_power(priv);
+                                break;
+                        default:
                                 ideapad_input_report(priv, vpc_bit);
+                        }
                 }
         }
 }