text: /*
   * MSI WMI hotkeys
   *
   * Copyright (C) 2009 Novell <trenn@suse.de>
   *
   * Most stuff taken over from hp-wmi
   *
   *  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/input.h>
  #include <linux/input/sparse-keymap.h>
  #include <linux/acpi.h>
  #include <linux/backlight.h>
  #include <linux/slab.h>
  
  MODULE_AUTHOR("Thomas Renninger <trenn@suse.de>");
  MODULE_DESCRIPTION("MSI laptop WMI hotkeys driver");
  MODULE_LICENSE("GPL");
  
  MODULE_ALIAS("wmi:551A1F84-FBDD-4125-91DB-3EA8F44F1D45");
  MODULE_ALIAS("wmi:B6F3EEF2-3D2F-49DC-9DE3-85BCE18C62F2");
  
  #define DRV_NAME "msi-wmi"
  #define DRV_PFX DRV_NAME ": "
  
  #define MSIWMI_BIOS_GUID "551A1F84-FBDD-4125-91DB-3EA8F44F1D45"
  #define MSIWMI_EVENT_GUID "B6F3EEF2-3D2F-49DC-9DE3-85BCE18C62F2"
  
  #define dprintk(msg...) pr_debug(DRV_PFX msg)
  
  #define KEYCODE_BASE 0xD0
  #define MSI_WMI_BRIGHTNESSUP   KEYCODE_BASE
  #define MSI_WMI_BRIGHTNESSDOWN (KEYCODE_BASE + 1)
  #define MSI_WMI_VOLUMEUP       (KEYCODE_BASE + 2)
  #define MSI_WMI_VOLUMEDOWN     (KEYCODE_BASE + 3)
  static struct key_entry msi_wmi_keymap[] = {
  	{ KE_KEY, MSI_WMI_BRIGHTNESSUP,   {KEY_BRIGHTNESSUP} },
  	{ KE_KEY, MSI_WMI_BRIGHTNESSDOWN, {KEY_BRIGHTNESSDOWN} },
  	{ KE_KEY, MSI_WMI_VOLUMEUP,       {KEY_VOLUMEUP} },
  	{ KE_KEY, MSI_WMI_VOLUMEDOWN,     {KEY_VOLUMEDOWN} },
  	{ KE_END, 0}
  };
  static ktime_t last_pressed[ARRAY_SIZE(msi_wmi_keymap) - 1];
  
  struct backlight_device *backlight;
  
  static int backlight_map[] = { 0x00, 0x33, 0x66, 0x99, 0xCC, 0xFF };
  
  static struct input_dev *msi_wmi_input_dev;
  
  static int msi_wmi_query_block(int instance, int *ret)
  {
  	acpi_status status;
  	union acpi_object *obj;
  
  	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
  
  	status = wmi_query_block(MSIWMI_BIOS_GUID, instance, &output);
  
  	obj = output.pointer;
  
  	if (!obj || obj->type != ACPI_TYPE_INTEGER) {
  		if (obj) {
  			printk(KERN_ERR DRV_PFX "query block returned object "
  			       "type: %d - buffer length:%d\n", obj->type,
  			       obj->type == ACPI_TYPE_BUFFER ?
  			       obj->buffer.length : 0);
  		}
  		kfree(obj);
  		return -EINVAL;
  	}
  	*ret = obj->integer.value;
  	kfree(obj);
  	return 0;
  }
  
  static int msi_wmi_set_block(int instance, int value)
  {
  	acpi_status status;
  
  	struct acpi_buffer input = { sizeof(int), &value };
  
  	dprintk("Going to set block of instance: %d - value: %d\n",
  		instance, value);
  
  	status = wmi_set_block(MSIWMI_BIOS_GUID, instance, &input);
  
  	return ACPI_SUCCESS(status) ? 0 : 1;
  }
  
  static int bl_get(struct backlight_device *bd)
  {
  	int level, err, ret;
  
  	/* Instance 1 is "get backlight", cmp with DSDT */
  	err = msi_wmi_query_block(1, &ret);
  	if (err) {
  		printk(KERN_ERR DRV_PFX "Could not query backlight: %d\n", err);
  		return -EINVAL;
  	}
  	dprintk("Get: Query block returned: %d\n", ret);
  	for (level = 0; level < ARRAY_SIZE(backlight_map); level++) {
  		if (backlight_map[level] == ret) {
  			dprintk("Current backlight level: 0x%X - index: %d\n",
  				backlight_map[level], level);
  			break;
  		}
  	}
  	if (level == ARRAY_SIZE(backlight_map)) {
  		printk(KERN_ERR DRV_PFX "get: Invalid brightness value: 0x%X\n",
  		       ret);
  		return -EINVAL;
  	}
  	return level;
  }
  
  static int bl_set_status(struct backlight_device *bd)
  {
  	int bright = bd->props.brightness;
  	if (bright >= ARRAY_SIZE(backlight_map) || bright < 0)
  		return -EINVAL;
  
  	/* Instance 0 is "set backlight" */
  	return msi_wmi_set_block(0, backlight_map[bright]);
  }
  
  static const struct backlight_ops msi_backlight_ops = {
  	.get_brightness	= bl_get,
  	.update_status	= bl_set_status,
  };
  
  static void msi_wmi_notify(u32 value, void *context)
  {
  	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
  	static struct key_entry *key;
  	union acpi_object *obj;
  	ktime_t cur;
  	acpi_status status;
  
  	status = wmi_get_event_data(value, &response);
  	if (status != AE_OK) {
  		printk(KERN_INFO DRV_PFX "bad event status 0x%x\n", status);
  		return;
  	}
  
  	obj = (union acpi_object *)response.pointer;
  
  	if (obj && obj->type == ACPI_TYPE_INTEGER) {
  		int eventcode = obj->integer.value;
  		dprintk("Eventcode: 0x%x\n", eventcode);
  		key = sparse_keymap_entry_from_scancode(msi_wmi_input_dev,
  				eventcode);
  		if (key) {
  			ktime_t diff;
  			cur = ktime_get_real();
  			diff = ktime_sub(cur, last_pressed[key->code -
  					KEYCODE_BASE]);
  			/* Ignore event if the same event happened in a 50 ms
  			   timeframe -> Key press may result in 10-20 GPEs */
  			if (ktime_to_us(diff) < 1000 * 50) {
  				dprintk("Suppressed key event 0x%X - "
  					"Last press was %lld us ago\n",
  					 key->code, ktime_to_us(diff));
  				return;
  			}
  			last_pressed[key->code - KEYCODE_BASE] = cur;
  
  			if (key->type == KE_KEY &&
  			/* Brightness is served via acpi video driver */
  			(!acpi_video_backlight_support() ||
  			(key->code != MSI_WMI_BRIGHTNESSUP &&
  			key->code != MSI_WMI_BRIGHTNESSDOWN))) {
  				dprintk("Send key: 0x%X - "
  					"Input layer keycode: %d\n", key->code,
  					 key->keycode);
  				sparse_keymap_report_entry(msi_wmi_input_dev,
  						key, 1, true);
  			}
  		} else
  			printk(KERN_INFO "Unknown key pressed - %x\n",
  			       eventcode);
  	} else
  		printk(KERN_INFO DRV_PFX "Unknown event received\n");
  	kfree(response.pointer);
  }
  
  static int __init msi_wmi_input_setup(void)
  {
  	int err;
  
  	msi_wmi_input_dev = input_allocate_device();
  	if (!msi_wmi_input_dev)
  		return -ENOMEM;
  
  	msi_wmi_input_dev->name = "MSI WMI hotkeys";
  	msi_wmi_input_dev->phys = "wmi/input0";
  	msi_wmi_input_dev->id.bustype = BUS_HOST;
  
  	err = sparse_keymap_setup(msi_wmi_input_dev, msi_wmi_keymap, NULL);
  	if (err)
  		goto err_free_dev;
  
  	err = input_register_device(msi_wmi_input_dev);
  
  	if (err)
  		goto err_free_keymap;
  
  	memset(last_pressed, 0, sizeof(last_pressed));
  
  	return 0;
  
  err_free_keymap:
  	sparse_keymap_free(msi_wmi_input_dev);
  err_free_dev:
  	input_free_device(msi_wmi_input_dev);
  	return err;
  }
  
  static int __init msi_wmi_init(void)
  {
  	int err;
  
  	if (!wmi_has_guid(MSIWMI_EVENT_GUID)) {
  		printk(KERN_ERR
  		       "This machine doesn't have MSI-hotkeys through WMI\n");
  		return -ENODEV;
  	}
  	err = wmi_install_notify_handler(MSIWMI_EVENT_GUID,
  			msi_wmi_notify, NULL);
  	if (ACPI_FAILURE(err))
  		return -EINVAL;
  
  	err = msi_wmi_input_setup();
  	if (err)
  		goto err_uninstall_notifier;
  
  	if (!acpi_video_backlight_support()) {
  		struct backlight_properties props;
  		memset(&props, 0, sizeof(struct backlight_properties));
  		props.max_brightness = ARRAY_SIZE(backlight_map) - 1;
  		backlight = backlight_device_register(DRV_NAME, NULL, NULL,
  						      &msi_backlight_ops,
  						      &props);
  		if (IS_ERR(backlight)) {
  			err = PTR_ERR(backlight);
  			goto err_free_input;
  		}
  
  		err = bl_get(NULL);
  		if (err < 0)
  			goto err_free_backlight;
  
  		backlight->props.brightness = err;
  	}
  	dprintk("Event handler installed\n");
  
  	return 0;
  
  err_free_backlight:
  	backlight_device_unregister(backlight);
  err_free_input:
  	input_unregister_device(msi_wmi_input_dev);
  err_uninstall_notifier:
  	wmi_remove_notify_handler(MSIWMI_EVENT_GUID);
  	return err;
  }
  
  static void __exit msi_wmi_exit(void)
  {
  	if (wmi_has_guid(MSIWMI_EVENT_GUID)) {
  		wmi_remove_notify_handler(MSIWMI_EVENT_GUID);
  		sparse_keymap_free(msi_wmi_input_dev);
  		input_unregister_device(msi_wmi_input_dev);
  		backlight_device_unregister(backlight);
  	}
  }
  
  module_init(msi_wmi_init);
  module_exit(msi_wmi_exit);
  