toshiba-acpi: Add support for Toshiba Illumination.

Add support for Toshiba Illumination. This is a set of LEDs installed on
some Toshiba laptops. It is controlled through ACPI, the commands has been
found through reverse engineering. It has been tested on a Toshiba Qosmio
G50-122.
Signed-off-by: NPierre Ducroquet <pinaraf@pinaraf.info>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

drivers/platform/x86/toshiba_acpi.c

@@ -4,6 +4,7 @@
  *
  *  Copyright (C) 2002-2004 John Belmonte
  *  Copyright (C) 2008 Philip Langdale
+ *  Copyright (C) 2010 Pierre Ducroquet
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -47,6 +48,7 @@
 #include <linux/platform_device.h>
 #include <linux/rfkill.h>
 #include <linux/input.h>
+#include <linux/leds.h>
 #include <linux/slab.h>
 
 #include <asm/uaccess.h>
@@ -287,6 +289,7 @@ struct toshiba_acpi_dev {
 	struct platform_device *p_dev;
 	struct rfkill *bt_rfk;
 	struct input_dev *hotkey_dev;
+	int illumination_installed;
 	acpi_handle handle;
 
 	const char *bt_name;
@@ -294,6 +297,110 @@ struct toshiba_acpi_dev {
 	struct mutex mutex;
 };
 
+/* Illumination support */
+static int toshiba_illumination_available(void)
+{
+	u32 in[HCI_WORDS] = { 0, 0, 0, 0, 0, 0 };
+	u32 out[HCI_WORDS];
+	acpi_status status;
+
+	in[0] = 0xf100;
+	status = hci_raw(in, out);
+	if (ACPI_FAILURE(status)) {
+		printk(MY_INFO "Illumination device not available\n");
+		return 0;
+	}
+	in[0] = 0xf400;
+	status = hci_raw(in, out);
+	return 1;
+}
+
+static void toshiba_illumination_set(struct led_classdev *cdev,
+				     enum led_brightness brightness)
+{
+	u32 in[HCI_WORDS] = { 0, 0, 0, 0, 0, 0 };
+	u32 out[HCI_WORDS];
+	acpi_status status;
+
+	/* First request : initialize communication. */
+	in[0] = 0xf100;
+	status = hci_raw(in, out);
+	if (ACPI_FAILURE(status)) {
+		printk(MY_INFO "Illumination device not available\n");
+		return;
+	}
+
+	if (brightness) {
+		/* Switch the illumination on */
+		in[0] = 0xf400;
+		in[1] = 0x14e;
+		in[2] = 1;
+		status = hci_raw(in, out);
+		if (ACPI_FAILURE(status)) {
+			printk(MY_INFO "ACPI call for illumination failed.\n");
+			return;
+		}
+	} else {
+		/* Switch the illumination off */
+		in[0] = 0xf400;
+		in[1] = 0x14e;
+		in[2] = 0;
+		status = hci_raw(in, out);
+		if (ACPI_FAILURE(status)) {
+			printk(MY_INFO "ACPI call for illumination failed.\n");
+			return;
+		}
+	}
+
+	/* Last request : close communication. */
+	in[0] = 0xf200;
+	in[1] = 0;
+	in[2] = 0;
+	hci_raw(in, out);
+}
+
+static enum led_brightness toshiba_illumination_get(struct led_classdev *cdev)
+{
+	u32 in[HCI_WORDS] = { 0, 0, 0, 0, 0, 0 };
+	u32 out[HCI_WORDS];
+	acpi_status status;
+	enum led_brightness result;
+
+	/* First request : initialize communication. */
+	in[0] = 0xf100;
+	status = hci_raw(in, out);
+	if (ACPI_FAILURE(status)) {
+		printk(MY_INFO "Illumination device not available\n");
+		return LED_OFF;
+	}
+
+	/* Check the illumination */
+	in[0] = 0xf300;
+	in[1] = 0x14e;
+	status = hci_raw(in, out);
+	if (ACPI_FAILURE(status)) {
+		printk(MY_INFO "ACPI call for illumination failed.\n");
+		return LED_OFF;
+	}
+
+	result = out[2] ? LED_FULL : LED_OFF;
+
+	/* Last request : close communication. */
+	in[0] = 0xf200;
+	in[1] = 0;
+	in[2] = 0;
+	hci_raw(in, out);
+
+	return result;
+}
+
+static struct led_classdev toshiba_led = {
+	.name           = "toshiba::illumination",
+	.max_brightness = 1,
+	.brightness_set = toshiba_illumination_set,
+	.brightness_get = toshiba_illumination_get,
+};
+
 static struct toshiba_acpi_dev toshiba_acpi = {
 	.bt_name = "Toshiba Bluetooth",
 };
@@ -913,6 +1020,9 @@ static void toshiba_acpi_exit(void)
 	acpi_remove_notify_handler(toshiba_acpi.handle, ACPI_DEVICE_NOTIFY,
 				   toshiba_acpi_notify);
 
+	if (toshiba_acpi.illumination_installed)
+		led_classdev_unregister(&toshiba_led);
+
 	platform_device_unregister(toshiba_acpi.p_dev);
 
 	return;
@@ -1007,6 +1117,13 @@ static int __init toshiba_acpi_init(void)
 		}
 	}
 
+	toshiba_acpi.illumination_installed = 0;
+	if (toshiba_illumination_available()) {
+		if (!led_classdev_register(&(toshiba_acpi.p_dev->dev),
+					   &toshiba_led))
+			toshiba_acpi.illumination_installed = 1;
+	}
+
 	return 0;
 }