platform/x86: toshiba_acpi: Update KBD backlight LED on second gen laptops

Second generation keyboard backlight (type 2) laptops can switch
on the keyboard LED on their own via hardware/firmware, but the
LED subsystem is unaware of such change since the LED interface
was only being created on first generation keyboard backlight
(type 1) laptops.

This patch creates the LED interface for second gen keyboards
and calls the *_hw_changed API whenever userspace changes the
state of the keyboard backlight LED.

While we are at it, remove an unneeded asignment to the acpi_dev
struct under *_kbd_bl_work, and also update the kbd_event_generated
variable in the main toshiba struct instead of the global struct.
Signed-off-by: NAzael Avalos <coproscefalo@gmail.com>
[dvhart: correct int* and int compare with dev->kbd_mode]
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

drivers/platform/x86/toshiba_acpi.c

@@ -1836,6 +1836,7 @@ static ssize_t kbd_backlight_mode_store(struct device *dev,
 			return ret;
 
 		toshiba->kbd_mode = mode;
+		toshiba_acpi->kbd_mode = mode;
 
 		/*
 		 * Some laptop models with the second generation backlit
@@ -1852,7 +1853,7 @@ static ssize_t kbd_backlight_mode_store(struct device *dev,
 		 * event via genetlink.
 		 */
 		if (toshiba->kbd_type == 2 &&
-		    !toshiba_acpi->kbd_event_generated)
+		    !toshiba->kbd_event_generated)
 			schedule_work(&kbd_bl_work);
 	}
 
@@ -2413,16 +2414,21 @@ static const struct attribute_group toshiba_attr_group = {
 
 static void toshiba_acpi_kbd_bl_work(struct work_struct *work)
 {
-	struct acpi_device *acpi_dev = toshiba_acpi->acpi_dev;
-
 	/* Update the sysfs entries */
-	if (sysfs_update_group(&acpi_dev->dev.kobj,
+	if (sysfs_update_group(&toshiba_acpi->acpi_dev->dev.kobj,
 			       &toshiba_attr_group))
 		pr_err("Unable to update sysfs entries\n");
 
+	/* Notify LED subsystem about keyboard backlight change */
+	if (toshiba_acpi->kbd_type == 2 &&
+	    toshiba_acpi->kbd_mode != SCI_KBD_MODE_AUTO)
+		led_classdev_notify_brightness_hw_changed(&toshiba_acpi->kbd_led,
+				(toshiba_acpi->kbd_mode == SCI_KBD_MODE_ON) ?
+				LED_FULL : LED_OFF);
+
 	/* Emulate the keyboard backlight event */
-	acpi_bus_generate_netlink_event(acpi_dev->pnp.device_class,
-					dev_name(&acpi_dev->dev),
+	acpi_bus_generate_netlink_event(toshiba_acpi->acpi_dev->pnp.device_class,
+					dev_name(&toshiba_acpi->acpi_dev->dev),
 					0x92, 0);
 }
 
@@ -3119,9 +3125,12 @@ static int toshiba_acpi_add(struct acpi_device *acpi_dev)
 	/*
 	 * Only register the LED if KBD illumination is supported
 	 * and the keyboard backlight operation mode is set to FN-Z
+	 * or we detect a second gen keyboard backlight
 	 */
-	if (dev->kbd_illum_supported && dev->kbd_mode == SCI_KBD_MODE_FNZ) {
+	if (dev->kbd_illum_supported &&
+	    (dev->kbd_mode == SCI_KBD_MODE_FNZ || dev->kbd_type == 2)) {
 		dev->kbd_led.name = "toshiba::kbd_backlight";
+		dev->kbd_led.flags = LED_BRIGHT_HW_CHANGED;
 		dev->kbd_led.max_brightness = 1;
 		dev->kbd_led.brightness_set = toshiba_kbd_backlight_set;
 		dev->kbd_led.brightness_get = toshiba_kbd_backlight_get;
@@ -3237,11 +3246,16 @@ static void toshiba_acpi_notify(struct acpi_device *acpi_dev, u32 event)
 		pr_info("SATA power event received %x\n", event);
 		break;
 	case 0x92: /* Keyboard backlight mode changed */
-		toshiba_acpi->kbd_event_generated = true;
+		dev->kbd_event_generated = true;
 		/* Update sysfs entries */
 		if (sysfs_update_group(&acpi_dev->dev.kobj,
 				       &toshiba_attr_group))
 			pr_err("Unable to update sysfs entries\n");
+		/* Notify LED subsystem about keyboard backlight change */
+		if (dev->kbd_type == 2 && dev->kbd_mode != SCI_KBD_MODE_AUTO)
+			led_classdev_notify_brightness_hw_changed(&dev->kbd_led,
+					(dev->kbd_mode == SCI_KBD_MODE_ON) ?
+					LED_FULL : LED_OFF);
 		break;
 	case 0x85: /* Unknown */
 	case 0x8d: /* Unknown */