asus-wmi: control backlight power through WMI, not ACPI

BugLink: https://bugs.launchpad.net/bugs/1000146

Some h/w that can adjust screen brightness through ACPI functions, but
can't turn on/off the backlight power correctly. So, we list those h/w in
quirks and try to turn on/off the backlight power through WMI.
Signed-off-by: AceLan Kao <acelan.kao@canonical.com>
Signed-off-by: Corentin Chary <corentin.chary@gmail.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

drivers/platform/x86/asus-wmi.c

@@ -47,6 +47,9 @@
 #include <linux/thermal.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>
+#ifdef CONFIG_ACPI_VIDEO
+#include <acpi/video.h>
+#endif
 
 #include "asus-wmi.h"
 
@@ -1676,7 +1679,13 @@ static int asus_wmi_add(struct platform_device *pdev)
 	if (err)
 		goto fail_rfkill;
 
+	if (asus->driver->quirks->wmi_backlight_power)
+		acpi_video_dmi_promote_vendor();
 	if (!acpi_video_backlight_support()) {
+#ifdef CONFIG_ACPI_VIDEO
+		pr_info("Disabling ACPI video driver\n");
+		acpi_video_unregister();
+#endif
 		err = asus_wmi_backlight_init(asus);
 		if (err && err != -ENODEV)
 			goto fail_backlight;

drivers/platform/x86/asus-wmi.h

@@ -39,6 +39,7 @@ struct quirk_entry {
 	bool hotplug_wireless;
 	bool scalar_panel_brightness;
 	bool store_backlight_power;
+	bool wmi_backlight_power;
 	int wapf;
 };
 

drivers/platform/x86/eeepc-wmi.c

@@ -79,7 +79,7 @@ static const struct key_entry eeepc_wmi_keymap[] = {
 	{ KE_KEY, 0xe1, { KEY_F14 } }, /* Change Resolution */
 	{ KE_KEY, HOME_PRESS, { KEY_CONFIG } }, /* Home/Express gate key */
 	{ KE_KEY, 0xe8, { KEY_SCREENLOCK } },
-	{ KE_KEY, 0xe9, { KEY_BRIGHTNESS_ZERO } },
+	{ KE_KEY, 0xe9, { KEY_DISPLAYTOGGLE } },
 	{ KE_KEY, 0xeb, { KEY_CAMERA_ZOOMOUT } },
 	{ KE_KEY, 0xec, { KEY_CAMERA_UP } },
 	{ KE_KEY, 0xed, { KEY_CAMERA_DOWN } },
@@ -107,6 +107,11 @@ static struct quirk_entry quirk_asus_et2012_type3 = {
 	.store_backlight_power = true,
 };
 
+static struct quirk_entry quirk_asus_x101ch = {
+	/* We need this when ACPI function doesn't do this well */
+	.wmi_backlight_power = true,
+};
+
 static struct quirk_entry *quirks;
 
 static void et2012_quirks(void)
@@ -157,6 +162,24 @@ static struct dmi_system_id asus_quirks[] = {
 		},
 		.driver_data = &quirk_asus_unknown,
 	},
+	{
+		.callback = dmi_matched,
+		.ident = "ASUSTeK Computer INC. X101CH",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "X101CH"),
+		},
+		.driver_data = &quirk_asus_x101ch,
+	},
+	{
+		.callback = dmi_matched,
+		.ident = "ASUSTeK Computer INC. 1015CX",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "1015CX"),
+		},
+		.driver_data = &quirk_asus_x101ch,
+	},
 	{},
 };