dell-wmi: new driver for hotkey control

Add a WMI driver for Dell laptops. Currently it does nothing but send a
generic input event when a button with a picture of a battery on it is
pressed, but maybe other uses will appear over time.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

3 files changed, 221 insertions, 0 deletions

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 3608081bc3e..a27bff3007c 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -67,6 +67,16 @@ config DELL_LAPTOP
         This driver adds support for rfkill and backlight control to Dell
         laptops.
 
+config DELL_WMI
+        tristate "Dell WMI extras"
+        depends on ACPI_WMI
+        depends on INPUT
+        ---help---
+          Say Y here if you want to support WMI-based hotkeys on Dell laptops.
+
+          To compile this driver as a module, choose M here: the module will
+          be called dell-wmi.
+
 config FUJITSU_LAPTOP
         tristate "Fujitsu Laptop Extras"
         depends on ACPI
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index e29065120be..e40c7bd1b87 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_EEEPC_LAPTOP)	+= eeepc-laptop.o
 obj-$(CONFIG_MSI_LAPTOP)        += msi-laptop.o
 obj-$(CONFIG_COMPAL_LAPTOP)     += compal-laptop.o
 obj-$(CONFIG_DELL_LAPTOP)       += dell-laptop.o
+obj-$(CONFIG_DELL_WMI)          += dell-wmi.o
 obj-$(CONFIG_ACER_WMI)          += acer-wmi.o
 obj-$(CONFIG_HP_WMI)            += hp-wmi.o
 obj-$(CONFIG_TC1100_WMI)        += tc1100-wmi.o
diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c
new file mode 100644
index 00000000000..2fab9416214
--- /dev/null
+++ b/drivers/platform/x86/dell-wmi.c
@@ -0,0 +1,210 @@
+/*
+ * Dell WMI hotkeys
+ *
+ * Copyright (C) 2008 Red Hat <mjg@redhat.com>
+ *
+ * Portions based on wistron_btns.c:
+ * Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
+ * Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
+ * Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
+ *
+ *  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
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/input.h>
+#include <acpi/acpi_drivers.h>
+#include <linux/acpi.h>
+#include <linux/string.h>
+
+MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
+MODULE_DESCRIPTION("Dell laptop WMI hotkeys driver");
+MODULE_LICENSE("GPL");
+
+#define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492"
+
+MODULE_ALIAS("wmi:"DELL_EVENT_GUID);
+
+struct key_entry {
+        char type;              /* See KE_* below */
+        u16 code;
+        u16 keycode;
+};
+
+enum { KE_KEY, KE_SW, KE_END };
+
+static struct key_entry dell_wmi_keymap[] = {
+        {KE_KEY, 0xe045, KEY_PROG1},
+        {KE_END, 0}
+};
+
+static struct input_dev *dell_wmi_input_dev;
+
+static struct key_entry *dell_wmi_get_entry_by_scancode(int code)
+{
+        struct key_entry *key;
+
+        for (key = dell_wmi_keymap; key->type != KE_END; key++)
+                if (code == key->code)
+                        return key;
+
+        return NULL;
+}
+
+static struct key_entry *dell_wmi_get_entry_by_keycode(int keycode)
+{
+        struct key_entry *key;
+
+        for (key = dell_wmi_keymap; key->type != KE_END; key++)
+                if (key->type == KE_KEY && keycode == key->keycode)
+                        return key;
+
+        return NULL;
+}
+
+static int dell_wmi_getkeycode(struct input_dev *dev, int scancode,
+                               int *keycode)
+{
+        struct key_entry *key = dell_wmi_get_entry_by_scancode(scancode);
+
+        if (key && key->type == KE_KEY) {
+                *keycode = key->keycode;
+                return 0;
+        }
+
+        return -EINVAL;
+}
+
+static int dell_wmi_setkeycode(struct input_dev *dev, int scancode, int keycode)
+{
+        struct key_entry *key;
+        int old_keycode;
+
+        if (keycode < 0 || keycode > KEY_MAX)
+                return -EINVAL;
+
+        key = dell_wmi_get_entry_by_scancode(scancode);
+        if (key && key->type == KE_KEY) {
+                old_keycode = key->keycode;
+                key->keycode = keycode;
+                set_bit(keycode, dev->keybit);
+                if (!dell_wmi_get_entry_by_keycode(old_keycode))
+                        clear_bit(old_keycode, dev->keybit);
+                return 0;
+        }
+        return -EINVAL;
+}
+
+static void dell_wmi_notify(u32 value, void *context)
+{
+        struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
+        static struct key_entry *key;
+        union acpi_object *obj;
+
+        wmi_get_event_data(value, &response);
+
+        obj = (union acpi_object *)response.pointer;
+
+        if (obj && obj->type == ACPI_TYPE_BUFFER) {
+                int *buffer = (int *)obj->buffer.pointer;
+                key = dell_wmi_get_entry_by_scancode(buffer[1]);
+                if (key) {
+                        input_report_key(dell_wmi_input_dev, key->keycode, 1);
+                        input_sync(dell_wmi_input_dev);
+                        input_report_key(dell_wmi_input_dev, key->keycode, 0);
+                        input_sync(dell_wmi_input_dev);
+                } else
+                        printk(KERN_INFO "dell-wmi: Unknown key %x pressed\n",
+                               buffer[1]);
+        }
+}
+
+static int __init dell_wmi_input_setup(void)
+{
+        struct key_entry *key;
+        int err;
+
+        dell_wmi_input_dev = input_allocate_device();
+
+        if (!dell_wmi_input_dev)
+                return -ENOMEM;
+
+        dell_wmi_input_dev->name = "Dell WMI hotkeys";
+        dell_wmi_input_dev->phys = "wmi/input0";
+        dell_wmi_input_dev->id.bustype = BUS_HOST;
+        dell_wmi_input_dev->getkeycode = dell_wmi_getkeycode;
+        dell_wmi_input_dev->setkeycode = dell_wmi_setkeycode;
+
+        for (key = dell_wmi_keymap; key->type != KE_END; key++) {
+                switch (key->type) {
+                case KE_KEY:
+                        set_bit(EV_KEY, dell_wmi_input_dev->evbit);
+                        set_bit(key->keycode, dell_wmi_input_dev->keybit);
+                        break;
+                case KE_SW:
+                        set_bit(EV_SW, dell_wmi_input_dev->evbit);
+                        set_bit(key->keycode, dell_wmi_input_dev->swbit);
+                        break;
+                }
+        }
+
+        err = input_register_device(dell_wmi_input_dev);
+
+        if (err) {
+                input_free_device(dell_wmi_input_dev);
+                return err;
+        }
+
+        return 0;
+}
+
+static int __init dell_wmi_init(void)
+{
+        int err;
+
+        if (wmi_has_guid(DELL_EVENT_GUID)) {
+                err = dell_wmi_input_setup();
+
+                if (err)
+                        return err;
+
+                err = wmi_install_notify_handler(DELL_EVENT_GUID,
+                                                 dell_wmi_notify, NULL);
+                if (err) {
+                        input_unregister_device(dell_wmi_input_dev);
+                        printk(KERN_ERR "dell-wmi: Unable to register"
+                               " notify handler - %d\n", err);
+                        return err;
+                }
+
+        } else
+                printk(KERN_WARNING "dell-wmi: No known WMI GUID found\n");
+
+        return 0;
+}
+
+static void __exit dell_wmi_exit(void)
+{
+        if (wmi_has_guid(DELL_EVENT_GUID)) {
+                wmi_remove_notify_handler(DELL_EVENT_GUID);
+                input_unregister_device(dell_wmi_input_dev);
+        }
+}
+
+module_init(dell_wmi_init);
+module_exit(dell_wmi_exit);