toshiba_acpi: Add touchpad enable/disable support-

Toshiba laptops have two ways of letting userspace
know the touchpad has changed state, one with a
button on top of the touchpad that simply emmits
scancodes whenever enabled/disabled, and another one
by pressing Fn-F9 (touchpad toggle) hotkey.

This patch adds support to enable/disable the touchpad
by exposing the _touchpad_ file in sysfs that simply
makes a call to a SCI register, imitating what
Toshiba provided software does on Windows.

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

1 files changed, 81 insertions, 0 deletions

diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c
index 95ae1ffaf409..08c53768447b 100644
--- a/drivers/platform/x86/toshiba_acpi.c
+++ b/drivers/platform/x86/toshiba_acpi.c
@@ -114,6 +114,7 @@ MODULE_LICENSE("GPL");
 #define HCI_KBD_ILLUMINATION            0x0095
 #define SCI_ILLUMINATION                0x014e
 #define SCI_KBD_ILLUM_STATUS            0x015c
+#define SCI_TOUCHPAD                    0x050e
 
 /* field definitions */
 #define HCI_HOTKEY_DISABLE              0x0b
@@ -157,6 +158,7 @@ struct toshiba_acpi_dev {
         unsigned int tr_backlight_supported:1;
         unsigned int kbd_illum_supported:1;
         unsigned int kbd_led_registered:1;
+        unsigned int touchpad_supported:1;
         unsigned int sysfs_created:1;
 
         struct mutex mutex;
@@ -527,6 +529,47 @@ static void toshiba_kbd_backlight_set(struct led_classdev *cdev,
                 return;
         }
 }
+ 
+/* TouchPad support */
+static int toshiba_touchpad_set(struct toshiba_acpi_dev *dev, u32 state)
+{
+        u32 result;
+        acpi_status status;
+
+        if (!sci_open(dev))
+                return -EIO;
+
+        status = sci_write(dev, SCI_TOUCHPAD, state, &result);
+        sci_close(dev);
+        if (ACPI_FAILURE(status)) {
+                pr_err("ACPI call to set the touchpad failed\n");
+                return -EIO;
+        } else if (result == HCI_NOT_SUPPORTED) {
+                return -ENODEV;
+        }
+
+        return 0;
+}
+
+static int toshiba_touchpad_get(struct toshiba_acpi_dev *dev, u32 *state)
+{
+        u32 result;
+        acpi_status status;
+
+        if (!sci_open(dev))
+                return -EIO;
+
+        status = sci_read(dev, SCI_TOUCHPAD, state, &result);
+        sci_close(dev);
+        if (ACPI_FAILURE(status)) {
+                pr_err("ACPI call to query the touchpad failed\n");
+                return -EIO;
+        } else if (result == HCI_NOT_SUPPORTED) {
+                return -ENODEV;
+        }
+
+        return 0;
+}
 
 /* Bluetooth rfkill handlers */
 
@@ -1130,15 +1173,48 @@ static ssize_t toshiba_kbd_bl_timeout_show(struct device *dev,
 
         return sprintf(buf, "%i\n", time >> HCI_MISC_SHIFT);
 }
+ 
+static ssize_t toshiba_touchpad_store(struct device *dev,
+                                      struct device_attribute *attr,
+                                      const char *buf, size_t count)
+{
+        struct toshiba_acpi_dev *toshiba = dev_get_drvdata(dev);
+        int state;
+
+        /* Set the TouchPad on/off, 0 - Disable | 1 - Enable */
+        if (sscanf(buf, "%i", &state) == 1 && (state == 0 || state == 1)) {
+                if (toshiba_touchpad_set(toshiba, state) < 0)
+                        return -EIO;
+        }
+
+        return count;
+}
+
+static ssize_t toshiba_touchpad_show(struct device *dev,
+                                     struct device_attribute *attr, char *buf)
+{
+        struct toshiba_acpi_dev *toshiba = dev_get_drvdata(dev);
+        u32 state;
+        int ret;
+
+        ret = toshiba_touchpad_get(toshiba, &state);
+        if (ret < 0)
+                return ret;
+
+        return sprintf(buf, "%i\n", state);
+}
 
 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 DEVICE_ATTR(touchpad, S_IRUGO | S_IWUSR,
+                   toshiba_touchpad_show, toshiba_touchpad_store);
 
 static struct attribute *toshiba_attributes[] = {
         &dev_attr_kbd_backlight_mode.attr,
         &dev_attr_kbd_backlight_timeout.attr,
+        &dev_attr_touchpad.attr,
         NULL,
 };
 
@@ -1153,6 +1229,8 @@ static umode_t toshiba_sysfs_is_visible(struct kobject *kobj,
                 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;
+        else if (attr == &dev_attr_touchpad.attr)
+                exists = (drv->touchpad_supported) ? true : false;
 
         return exists ? attr->mode : 0;
 }
@@ -1496,6 +1574,9 @@ static int toshiba_acpi_add(struct acpi_device *acpi_dev)
                 if (!led_classdev_register(&dev->acpi_dev->dev, &dev->kbd_led))
                         dev->kbd_led_registered = 1;
         }
+ 
+        ret = toshiba_touchpad_get(dev, &dummy);
+        dev->touchpad_supported = !ret;
 
         /* Determine whether or not BIOS supports fan and video interfaces */