toshiba_acpi: Add keyboard backlight support

Toshiba laptops equiped with an illuminated keyboard
can operate in two different modes: Auto and FN-Z.

The Auto mode turns on the led on keystrokes and
automatically turns it off after some (configurable)
time the last key was pressed.

The FN-Z mode is used to toggle the keyboard led on/off
by userspace.

This patch adds support to set the desired KBD mode and
timeout via sysfs, creates and registers toshiba::kbd_backlight
led device whenever the mode is set to FN-Z.

The acceptable values for mode are: 1 (Auto) and 2 (Fn-Z)
The time values range are: 1-60 seconds

Signed-off-by: Azael Avalos <coproscefalo@gmail.com>
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

1 files changed, 240 insertions, 0 deletions

diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c
index 6ed5be030d58..95ae1ffaf409 100644
--- a/drivers/platform/x86/toshiba_acpi.c
+++ b/drivers/platform/x86/toshiba_acpi.c
@@ -111,7 +111,9 @@ MODULE_LICENSE("GPL");
 #define HCI_HOTKEY_EVENT                0x001e
 #define HCI_LCD_BRIGHTNESS              0x002a
 #define HCI_WIRELESS                    0x0056
+#define HCI_KBD_ILLUMINATION            0x0095
 #define SCI_ILLUMINATION                0x014e
+#define SCI_KBD_ILLUM_STATUS            0x015c
 
 /* field definitions */
 #define HCI_HOTKEY_DISABLE              0x0b
@@ -119,6 +121,7 @@ MODULE_LICENSE("GPL");
 #define HCI_LCD_BRIGHTNESS_BITS         3
 #define HCI_LCD_BRIGHTNESS_SHIFT        (16-HCI_LCD_BRIGHTNESS_BITS)
 #define HCI_LCD_BRIGHTNESS_LEVELS       (1 << HCI_LCD_BRIGHTNESS_BITS)
+#define HCI_MISC_SHIFT                  0x10
 #define HCI_VIDEO_OUT_LCD               0x1
 #define HCI_VIDEO_OUT_CRT               0x2
 #define HCI_VIDEO_OUT_TV                0x4
@@ -126,6 +129,8 @@ MODULE_LICENSE("GPL");
 #define HCI_WIRELESS_BT_PRESENT         0x0f
 #define HCI_WIRELESS_BT_ATTACH          0x40
 #define HCI_WIRELESS_BT_POWER           0x80
+#define SCI_KBD_MODE_FNZ                0x1
+#define SCI_KBD_MODE_AUTO               0x2
 
 struct toshiba_acpi_dev {
         struct acpi_device *acpi_dev;
@@ -135,10 +140,13 @@ struct toshiba_acpi_dev {
         struct work_struct hotkey_work;
         struct backlight_device *backlight_dev;
         struct led_classdev led_dev;
+        struct led_classdev kbd_led;
 
         int force_fan;
         int last_key_event;
         int key_event_valid;
+        int kbd_mode;
+        int kbd_time;
 
         unsigned int illumination_supported:1;
         unsigned int video_supported:1;
@@ -147,6 +155,9 @@ struct toshiba_acpi_dev {
         unsigned int ntfy_supported:1;
         unsigned int info_supported:1;
         unsigned int tr_backlight_supported:1;
+        unsigned int kbd_illum_supported:1;
+        unsigned int kbd_led_registered:1;
+        unsigned int sysfs_created:1;
 
         struct mutex mutex;
 };
@@ -433,6 +444,89 @@ static enum led_brightness toshiba_illumination_get(struct led_classdev *cdev)
 
         return state ? LED_FULL : LED_OFF;
 }
+ 
+/* KBD Illumination */
+static int toshiba_kbd_illum_status_set(struct toshiba_acpi_dev *dev, u32 time)
+{
+        u32 result;
+        acpi_status status;
+
+        if (!sci_open(dev))
+                return -EIO;
+
+        status = sci_write(dev, SCI_KBD_ILLUM_STATUS, time, &result);
+        sci_close(dev);
+        if (ACPI_FAILURE(status) || result == SCI_INPUT_DATA_ERROR) {
+                pr_err("ACPI call to set KBD backlight status failed\n");
+                return -EIO;
+        } else if (result == HCI_NOT_SUPPORTED) {
+                pr_info("Keyboard backlight status not supported\n");
+                return -ENODEV;
+        }
+
+        return 0;
+}
+
+static int toshiba_kbd_illum_status_get(struct toshiba_acpi_dev *dev, u32 *time)
+{
+        u32 result;
+        acpi_status status;
+
+        if (!sci_open(dev))
+                return -EIO;
+
+        status = sci_read(dev, SCI_KBD_ILLUM_STATUS, time, &result);
+        sci_close(dev);
+        if (ACPI_FAILURE(status) || result == SCI_INPUT_DATA_ERROR) {
+                pr_err("ACPI call to get KBD backlight status failed\n");
+                return -EIO;
+        } else if (result == HCI_NOT_SUPPORTED) {
+                pr_info("Keyboard backlight status not supported\n");
+                return -ENODEV;
+        }
+
+        return 0;
+}
+
+static enum led_brightness toshiba_kbd_backlight_get(struct led_classdev *cdev)
+{
+        struct toshiba_acpi_dev *dev = container_of(cdev,
+                        struct toshiba_acpi_dev, kbd_led);
+        u32 state, result;
+        acpi_status status;
+
+        /* Check the keyboard backlight state */
+        status = hci_read1(dev, HCI_KBD_ILLUMINATION, &state, &result);
+        if (ACPI_FAILURE(status) || result == SCI_INPUT_DATA_ERROR) {
+                pr_err("ACPI call to get the keyboard backlight failed\n");
+                return LED_OFF;
+        } else if (result == HCI_NOT_SUPPORTED) {
+                pr_info("Keyboard backlight not supported\n");
+                return LED_OFF;
+        }
+
+        return state ? LED_FULL : LED_OFF;
+}
+
+static void toshiba_kbd_backlight_set(struct led_classdev *cdev,
+                                     enum led_brightness brightness)
+{
+        struct toshiba_acpi_dev *dev = container_of(cdev,
+                        struct toshiba_acpi_dev, kbd_led);
+        u32 state, result;
+        acpi_status status;
+
+        /* Set the keyboard backlight state */
+        state = brightness ? 1 : 0;
+        status = hci_write1(dev, HCI_KBD_ILLUMINATION, state, &result);
+        if (ACPI_FAILURE(status) || result == SCI_INPUT_DATA_ERROR) {
+                pr_err("ACPI call to set KBD Illumination mode failed\n");
+                return;
+        } else if (result == HCI_NOT_SUPPORTED) {
+                pr_info("Keyboard backlight not supported\n");
+                return;
+        }
+}
 
 /* Bluetooth rfkill handlers */
 
@@ -956,6 +1050,117 @@ static const struct backlight_ops toshiba_backlight_data = {
         .get_brightness = get_lcd_brightness,
         .update_status  = set_lcd_status,
 };
+ 
+/*
+ * Sysfs files
+ */
+
+static ssize_t toshiba_kbd_bl_mode_store(struct device *dev,
+                                         struct device_attribute *attr,
+                                         const char *buf, size_t count)
+{
+        struct toshiba_acpi_dev *toshiba = dev_get_drvdata(dev);
+        int mode = -1;
+        int time = -1;
+
+        if (sscanf(buf, "%i", &mode) != 1 && (mode != 2 || mode != 1))
+                return -EINVAL;
+
+        /* Set the Keyboard Backlight Mode where:
+         * Mode - Auto (2) | FN-Z (1)
+         *      Auto - KBD backlight turns off automatically in given time
+         *      FN-Z - KBD backlight "toggles" when hotkey pressed
+         */
+        if (mode != -1 && toshiba->kbd_mode != mode) {
+                time = toshiba->kbd_time << HCI_MISC_SHIFT;
+                time = time + toshiba->kbd_mode;
+                if (toshiba_kbd_illum_status_set(toshiba, time) < 0)
+                        return -EIO;
+                toshiba->kbd_mode = mode;
+        }
+
+        return count;
+}
+
+static ssize_t toshiba_kbd_bl_mode_show(struct device *dev,
+                                        struct device_attribute *attr,
+                                        char *buf)
+{
+        struct toshiba_acpi_dev *toshiba = dev_get_drvdata(dev);
+        u32 time;
+
+        if (toshiba_kbd_illum_status_get(toshiba, &time) < 0)
+                return -EIO;
+
+        return sprintf(buf, "%i\n", time & 0x07);
+}
+
+static ssize_t toshiba_kbd_bl_timeout_store(struct device *dev,
+                                            struct device_attribute *attr,
+                                            const char *buf, size_t count)
+{
+        struct toshiba_acpi_dev *toshiba = dev_get_drvdata(dev);
+        int time = -1;
+
+        if (sscanf(buf, "%i", &time) != 1 && (time < 0 || time > 60))
+                return -EINVAL;
+
+        /* Set the Keyboard Backlight Timeout: 0-60 seconds */
+        if (time != -1 && toshiba->kbd_time != time) {
+                time = time << HCI_MISC_SHIFT;
+                time = (toshiba->kbd_mode == SCI_KBD_MODE_AUTO) ?
+                                                        time + 1 : time + 2;
+                if (toshiba_kbd_illum_status_set(toshiba, time) < 0)
+                        return -EIO;
+                toshiba->kbd_time = time >> HCI_MISC_SHIFT;
+        }
+
+        return count;
+}
+
+static ssize_t toshiba_kbd_bl_timeout_show(struct device *dev,
+                                           struct device_attribute *attr,
+                                           char *buf)
+{
+        struct toshiba_acpi_dev *toshiba = dev_get_drvdata(dev);
+        u32 time;
+
+        if (toshiba_kbd_illum_status_get(toshiba, &time) < 0)
+                return -EIO;
+
+        return sprintf(buf, "%i\n", time >> HCI_MISC_SHIFT);
+}
+
+static DEVICE_ATTR(kbd_backlight_mode, S_IRUGO | S_IWUSR,
+                   toshiba_kbd_bl_mode_show, toshiba_kbd_bl_mode_store);
+static DEVICE_ATTR(kbd_backlight_timeout, S_IRUGO | S_IWUSR,
+                   toshiba_kbd_bl_timeout_show, toshiba_kbd_bl_timeout_store);
+
+static struct attribute *toshiba_attributes[] = {
+        &dev_attr_kbd_backlight_mode.attr,
+        &dev_attr_kbd_backlight_timeout.attr,
+        NULL,
+};
+
+static umode_t toshiba_sysfs_is_visible(struct kobject *kobj,
+                                        struct attribute *attr, int idx)
+{
+        struct device *dev = container_of(kobj, struct device, kobj);
+        struct toshiba_acpi_dev *drv = dev_get_drvdata(dev);
+        bool exists = true;
+
+        if (attr == &dev_attr_kbd_backlight_mode.attr)
+                exists = (drv->kbd_illum_supported) ? true : false;
+        else if (attr == &dev_attr_kbd_backlight_timeout.attr)
+                exists = (drv->kbd_mode == SCI_KBD_MODE_AUTO) ? true : false;
+
+        return exists ? attr->mode : 0;
+}
+
+static struct attribute_group toshiba_attr_group = {
+        .is_visible = toshiba_sysfs_is_visible,
+        .attrs = toshiba_attributes,
+};
 
 static bool toshiba_acpi_i8042_filter(unsigned char data, unsigned char str,
                                       struct serio *port)
@@ -1158,6 +1363,10 @@ static int toshiba_acpi_remove(struct acpi_device *acpi_dev)
         struct toshiba_acpi_dev *dev = acpi_driver_data(acpi_dev);
 
         remove_toshiba_proc_entries(dev);
+ 
+        if (dev->sysfs_created)
+                sysfs_remove_group(&dev->acpi_dev->dev.kobj,
+                                   &toshiba_attr_group);
 
         if (dev->ntfy_supported) {
                 i8042_remove_filter(toshiba_acpi_i8042_filter);
@@ -1179,6 +1388,9 @@ static int toshiba_acpi_remove(struct acpi_device *acpi_dev)
 
         if (dev->illumination_supported)
                 led_classdev_unregister(&dev->led_dev);
+ 
+        if (dev->kbd_led_registered)
+                led_classdev_unregister(&dev->kbd_led);
 
         if (toshiba_acpi)
                 toshiba_acpi = NULL;
@@ -1225,6 +1437,7 @@ static int toshiba_acpi_add(struct acpi_device *acpi_dev)
         dev->acpi_dev = acpi_dev;
         dev->method_hci = hci_method;
         acpi_dev->driver_data = dev;
+        dev_set_drvdata(&acpi_dev->dev, dev);
 
         if (toshiba_acpi_setup_keyboard(dev))
                 pr_info("Unable to activate hotkeys\n");
@@ -1264,6 +1477,25 @@ static int toshiba_acpi_add(struct acpi_device *acpi_dev)
                 if (!led_classdev_register(&acpi_dev->dev, &dev->led_dev))
                         dev->illumination_supported = 1;
         }
+ 
+        ret = toshiba_kbd_illum_status_get(dev, &dummy);
+        if (!ret) {
+                dev->kbd_time = dummy >> HCI_MISC_SHIFT;
+                dev->kbd_mode = dummy & 0x07;
+        }
+        dev->kbd_illum_supported = !ret;
+        /*
+         * Only register the LED if KBD illumination is supported
+         * and the keyboard backlight operation mode is set to FN-Z
+         */
+        if (dev->kbd_illum_supported && dev->kbd_mode == SCI_KBD_MODE_FNZ) {
+                dev->kbd_led.name = "toshiba::kbd_backlight";
+                dev->kbd_led.max_brightness = 1;
+                dev->kbd_led.brightness_set = toshiba_kbd_backlight_set;
+                dev->kbd_led.brightness_get = toshiba_kbd_backlight_get;
+                if (!led_classdev_register(&dev->acpi_dev->dev, &dev->kbd_led))
+                        dev->kbd_led_registered = 1;
+        }
 
         /* Determine whether or not BIOS supports fan and video interfaces */
 
@@ -1273,6 +1505,14 @@ static int toshiba_acpi_add(struct acpi_device *acpi_dev)
         ret = get_fan_status(dev, &dummy);
         dev->fan_supported = !ret;
 
+        ret = sysfs_create_group(&dev->acpi_dev->dev.kobj,
+                                 &toshiba_attr_group);
+        if (ret) {
+                dev->sysfs_created = 0;
+                goto error;
+        }
+        dev->sysfs_created = !ret;
+
         create_toshiba_proc_entries(dev);
 
         toshiba_acpi = dev;