acer-wmi: Add acer wmi hotkey events support

Add acer wmi hotkey event support. Install a wmi notify handler to
transfer wmi event key to key code, then send out keycode through acer
wmi input device to userland.

Signed-off-by: Lee, Chun-Yi <jlee@novell.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Thomas Renninger <trenn@suse.de>
Acked-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Cc: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

2 files changed, 141 insertions, 0 deletions

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index fbee997d2c24..a122a0dac981 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -22,8 +22,10 @@ config ACER_WMI
         depends on NEW_LEDS
         depends on BACKLIGHT_CLASS_DEVICE
         depends on SERIO_I8042
+        depends on INPUT
         depends on RFKILL || RFKILL = n
         depends on ACPI_WMI
+        select INPUT_SPARSEKMAP
         ---help---
           This is a driver for newer Acer (and Wistron) laptops. It adds
           wireless radio and bluetooth control, and on some laptops,
diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index c8c65375bfe2..a1c6141f463b 100644
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c
@@ -37,6 +37,8 @@
 #include <linux/workqueue.h>
 #include <linux/debugfs.h>
 #include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/input/sparse-keymap.h>
 
 #include <acpi/acpi_drivers.h>
 
@@ -48,6 +50,7 @@ MODULE_LICENSE("GPL");
 #define ACER_ERR KERN_ERR ACER_LOGPREFIX
 #define ACER_NOTICE KERN_NOTICE ACER_LOGPREFIX
 #define ACER_INFO KERN_INFO ACER_LOGPREFIX
+#define ACER_WARNING KERN_WARNING ACER_LOGPREFIX
 
 /*
  * Magic Number
@@ -83,8 +86,39 @@ MODULE_LICENSE("GPL");
 #define WMID_GUID1              "6AF4F258-B401-42fd-BE91-3D4AC2D7C0D3"
 #define WMID_GUID2              "95764E09-FB56-4e83-B31A-37761F60994A"
 
+/*
+ * Acer ACPI event GUIDs
+ */
+#define ACERWMID_EVENT_GUID "676AA15E-6A47-4D9F-A2CC-1E6D18D14026"
+
 MODULE_ALIAS("wmi:67C3371D-95A3-4C37-BB61-DD47B491DAAB");
 MODULE_ALIAS("wmi:6AF4F258-B401-42fd-BE91-3D4AC2D7C0D3");
+MODULE_ALIAS("wmi:676AA15E-6A47-4D9F-A2CC-1E6D18D14026");
+
+enum acer_wmi_event_ids {
+        WMID_HOTKEY_EVENT = 0x1,
+};
+
+static const struct key_entry acer_wmi_keymap[] = {
+        {KE_KEY, 0x01, {KEY_WLAN} },     /* WiFi */
+        {KE_KEY, 0x12, {KEY_BLUETOOTH} },       /* BT */
+        {KE_KEY, 0x21, {KEY_PROG1} },    /* Backup */
+        {KE_KEY, 0x22, {KEY_PROG2} },    /* Arcade */
+        {KE_KEY, 0x23, {KEY_PROG3} },    /* P_Key */
+        {KE_KEY, 0x24, {KEY_PROG4} },    /* Social networking_Key */
+        {KE_KEY, 0x64, {KEY_SWITCHVIDEOMODE} }, /* Display Switch */
+        {KE_KEY, 0x82, {KEY_F22} },      /* Touch Pad On/Off */
+        {KE_END, 0}
+};
+
+static struct input_dev *acer_wmi_input_dev;
+
+struct event_return_value {
+        u8 function;
+        u8 key_num;
+        u16 device_state;
+        u32 reserved;
+} __attribute__((packed));
 
 /*
  * Interface capability flags
@@ -1085,6 +1119,99 @@ static ssize_t show_interface(struct device *dev, struct device_attribute *attr,
 
 static DEVICE_ATTR(interface, S_IRUGO, show_interface, NULL);
 
+static void acer_wmi_notify(u32 value, void *context)
+{
+        struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
+        union acpi_object *obj;
+        struct event_return_value return_value;
+        acpi_status status;
+
+        status = wmi_get_event_data(value, &response);
+        if (status != AE_OK) {
+                printk(ACER_WARNING "bad event status 0x%x\n", status);
+                return;
+        }
+
+        obj = (union acpi_object *)response.pointer;
+
+        if (!obj)
+                return;
+        if (obj->type != ACPI_TYPE_BUFFER) {
+                printk(ACER_WARNING "Unknown response received %d\n",
+                        obj->type);
+                kfree(obj);
+                return;
+        }
+        if (obj->buffer.length != 8) {
+                printk(ACER_WARNING "Unknown buffer length %d\n",
+                        obj->buffer.length);
+                kfree(obj);
+                return;
+        }
+
+        return_value = *((struct event_return_value *)obj->buffer.pointer);
+        kfree(obj);
+
+        switch (return_value.function) {
+        case WMID_HOTKEY_EVENT:
+                if (!sparse_keymap_report_event(acer_wmi_input_dev,
+                                return_value.key_num, 1, true))
+                        printk(ACER_WARNING "Unknown key number - 0x%x\n",
+                                return_value.key_num);
+                break;
+        default:
+                printk(ACER_WARNING "Unknown function number - %d - %d\n",
+                        return_value.function, return_value.key_num);
+                break;
+        }
+}
+
+static int __init acer_wmi_input_setup(void)
+{
+        acpi_status status;
+        int err;
+
+        acer_wmi_input_dev = input_allocate_device();
+        if (!acer_wmi_input_dev)
+                return -ENOMEM;
+
+        acer_wmi_input_dev->name = "Acer WMI hotkeys";
+        acer_wmi_input_dev->phys = "wmi/input0";
+        acer_wmi_input_dev->id.bustype = BUS_HOST;
+
+        err = sparse_keymap_setup(acer_wmi_input_dev, acer_wmi_keymap, NULL);
+        if (err)
+                goto err_free_dev;
+
+        status = wmi_install_notify_handler(ACERWMID_EVENT_GUID,
+                                                acer_wmi_notify, NULL);
+        if (ACPI_FAILURE(status)) {
+                err = -EIO;
+                goto err_free_keymap;
+        }
+
+        err = input_register_device(acer_wmi_input_dev);
+        if (err)
+                goto err_uninstall_notifier;
+
+        return 0;
+
+err_uninstall_notifier:
+        wmi_remove_notify_handler(ACERWMID_EVENT_GUID);
+err_free_keymap:
+        sparse_keymap_free(acer_wmi_input_dev);
+err_free_dev:
+        input_free_device(acer_wmi_input_dev);
+        return err;
+}
+
+static void acer_wmi_input_destroy(void)
+{
+        wmi_remove_notify_handler(ACERWMID_EVENT_GUID);
+        sparse_keymap_free(acer_wmi_input_dev);
+        input_unregister_device(acer_wmi_input_dev);
+}
+
 /*
  * debugfs functions
  */
@@ -1327,6 +1454,12 @@ static int __init acer_wmi_init(void)
                        "generic video driver\n");
         }
 
+        if (wmi_has_guid(ACERWMID_EVENT_GUID)) {
+                err = acer_wmi_input_setup();
+                if (err)
+                        return err;
+        }
+
         err = platform_driver_register(&acer_platform_driver);
         if (err) {
                 printk(ACER_ERR "Unable to register platform driver.\n");
@@ -1368,11 +1501,17 @@ error_device_add:
 error_device_alloc:
         platform_driver_unregister(&acer_platform_driver);
 error_platform_register:
+        if (wmi_has_guid(ACERWMID_EVENT_GUID))
+                acer_wmi_input_destroy();
+
         return err;
 }
 
 static void __exit acer_wmi_exit(void)
 {
+        if (wmi_has_guid(ACERWMID_EVENT_GUID))
+                acer_wmi_input_destroy();
+
         remove_sysfs(acer_platform_device);
         remove_debugfs();
         platform_device_unregister(acer_platform_device);