eeepc-wmi: support backlight power (bl_power) attribute

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

1 files changed, 61 insertions, 14 deletions

diff --git a/drivers/platform/x86/eeepc-wmi.c b/drivers/platform/x86/eeepc-wmi.c
index 75dd692d31ee..910eb00fb13e 100644
--- a/drivers/platform/x86/eeepc-wmi.c
+++ b/drivers/platform/x86/eeepc-wmi.c
@@ -73,13 +73,16 @@ MODULE_ALIAS("wmi:"EEEPC_WMI_MGMT_GUID);
 #define EEEPC_WMI_DEVID_BLUETOOTH       0x00010013
 #define EEEPC_WMI_DEVID_WIMAX           0x00010017
 #define EEEPC_WMI_DEVID_WWAN3G          0x00010019
-#define EEEPC_WMI_DEVID_BACKLIGHT       0x00050012
+#define EEEPC_WMI_DEVID_BACKLIGHT       0x00050011
+#define EEEPC_WMI_DEVID_BRIGHTNESS      0x00050012
 #define EEEPC_WMI_DEVID_CAMERA          0x00060013
 #define EEEPC_WMI_DEVID_CARDREADER      0x00080013
 #define EEEPC_WMI_DEVID_TPDLED          0x00100011
 
 #define EEEPC_WMI_DSTS_STATUS_BIT       0x00000001
 #define EEEPC_WMI_DSTS_PRESENCE_BIT     0x00010000
+#define EEEPC_WMI_DSTS_BRIGHTNESS_MASK  0x000000FF
+#define EEEPC_WMI_DSTS_MAX_BRIGTH_MASK  0x0000FF00
 
 static bool hotplug_wireless;
 
@@ -262,7 +265,7 @@ static acpi_status eeepc_wmi_set_devstate(u32 dev_id, u32 ctrl_param,
 }
 
 /* Helper for special devices with magic return codes */
-static int eeepc_wmi_get_devstate_simple(u32 dev_id)
+static int eeepc_wmi_get_devstate_bits(u32 dev_id, u32 mask)
 {
         u32 retval = 0;
         acpi_status status;
@@ -275,7 +278,12 @@ static int eeepc_wmi_get_devstate_simple(u32 dev_id)
         if (!(retval & EEEPC_WMI_DSTS_PRESENCE_BIT))
                 return -ENODEV;
 
-        return retval & EEEPC_WMI_DSTS_STATUS_BIT;
+        return retval & mask;
+}
+
+static int eeepc_wmi_get_devstate_simple(u32 dev_id)
+{
+        return eeepc_wmi_get_devstate_bits(dev_id, EEEPC_WMI_DSTS_STATUS_BIT);
 }
 
 /*
@@ -770,34 +778,53 @@ exit:
 /*
  * Backlight
  */
+static int read_backlight_power(void)
+{
+        int ret = eeepc_wmi_get_devstate_simple(EEEPC_WMI_DEVID_BACKLIGHT);
+
+        if (ret < 0)
+                return ret;
+
+        return ret ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
+}
+
 static int read_brightness(struct backlight_device *bd)
 {
         u32 retval;
         acpi_status status;
 
-        status = eeepc_wmi_get_devstate(EEEPC_WMI_DEVID_BACKLIGHT, &retval);
+        status = eeepc_wmi_get_devstate(EEEPC_WMI_DEVID_BRIGHTNESS, &retval);
 
         if (ACPI_FAILURE(status))
-                return -1;
+                return -EIO;
         else
-                return retval & 0xFF;
+                return retval & EEEPC_WMI_DSTS_BRIGHTNESS_MASK;
 }
 
 static int update_bl_status(struct backlight_device *bd)
 {
-
         u32 ctrl_param;
         acpi_status status;
+        int power;
 
         ctrl_param = bd->props.brightness;
 
-        status = eeepc_wmi_set_devstate(EEEPC_WMI_DEVID_BACKLIGHT,
+        status = eeepc_wmi_set_devstate(EEEPC_WMI_DEVID_BRIGHTNESS,
                                         ctrl_param, NULL);
 
         if (ACPI_FAILURE(status))
-                return -1;
-        else
-                return 0;
+                return -EIO;
+
+        power = read_backlight_power();
+        if (power != -ENODEV && bd->props.power != power) {
+                ctrl_param = !!(bd->props.power == FB_BLANK_UNBLANK);
+                status = eeepc_wmi_set_devstate(EEEPC_WMI_DEVID_BACKLIGHT,
+                                                ctrl_param, NULL);
+
+                if (ACPI_FAILURE(status))
+                        return -EIO;
+        }
+        return 0;
 }
 
 static const struct backlight_ops eeepc_wmi_bl_ops = {
@@ -827,9 +854,29 @@ static int eeepc_wmi_backlight_init(struct eeepc_wmi *eeepc)
 {
         struct backlight_device *bd;
         struct backlight_properties props;
+        int max;
+        int power;
+
+        max = eeepc_wmi_get_devstate_bits(EEEPC_WMI_DEVID_BRIGHTNESS,
+                                          EEEPC_WMI_DSTS_MAX_BRIGTH_MASK);
+        power = read_backlight_power();
+
+        if (max < 0 && power < 0) {
+                /* Try to keep the original error */
+                if (max == -ENODEV && power == -ENODEV)
+                        return -ENODEV;
+                if (max != -ENODEV)
+                        return max;
+                else
+                        return power;
+        }
+        if (max == -ENODEV)
+                max = 0;
+        if (power == -ENODEV)
+                power = FB_BLANK_UNBLANK;
 
         memset(&props, 0, sizeof(struct backlight_properties));
-        props.max_brightness = 15;
+        props.max_brightness = max;
         bd = backlight_device_register(EEEPC_WMI_FILE,
                                        &eeepc->platform_device->dev, eeepc,
                                        &eeepc_wmi_bl_ops, &props);
@@ -841,7 +888,7 @@ static int eeepc_wmi_backlight_init(struct eeepc_wmi *eeepc)
         eeepc->backlight_device = bd;
 
         bd->props.brightness = read_brightness(bd);
-        bd->props.power = FB_BLANK_UNBLANK;
+        bd->props.power = power;
         backlight_update_status(bd);
 
         return 0;
@@ -1202,7 +1249,7 @@ static int __init eeepc_wmi_add(struct platform_device *pdev)
 
         if (!acpi_video_backlight_support()) {
                 err = eeepc_wmi_backlight_init(eeepc);
-                if (err)
+                if (err && err != -ENODEV)
                         goto fail_backlight;
         } else
                 pr_info("Backlight controlled by ACPI video driver\n");