drivers/platform/x86/intel-hid.c - kernel/common - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  *  Intel HID event & 5 button array driver
  *
  *  Copyright (C) 2015 Alex Hung <[email protected]>
  *  Copyright (C) 2015 Andrew Lutomirski <[email protected]>
  */

 #include <linux/acpi.h>
 #include <linux/dmi.h>
 #include <linux/input.h>
 #include <linux/input/sparse-keymap.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/suspend.h>

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Alex Hung");

 static const struct acpi_device_id intel_hid_ids[] = {
 	{"INT33D5", 0},
 	{"", 0},
 };

 /* In theory, these are HID usages. */
 static const struct key_entry intel_hid_keymap[] = {
 	/* 1: LSuper (Page 0x07, usage 0xE3) -- unclear what to do */
 	/* 2: Toggle SW_ROTATE_LOCK -- easy to implement if seen in wild */
 	{ KE_KEY, 3, { KEY_NUMLOCK } },
 	{ KE_KEY, 4, { KEY_HOME } },
 	{ KE_KEY, 5, { KEY_END } },
 	{ KE_KEY, 6, { KEY_PAGEUP } },
 	{ KE_KEY, 7, { KEY_PAGEDOWN } },
 	{ KE_KEY, 8, { KEY_RFKILL } },
 	{ KE_KEY, 9, { KEY_POWER } },
 	{ KE_KEY, 11, { KEY_SLEEP } },
 	/* 13 has two different meanings in the spec -- ignore it. */
 	{ KE_KEY, 14, { KEY_STOPCD } },
 	{ KE_KEY, 15, { KEY_PLAYPAUSE } },
 	{ KE_KEY, 16, { KEY_MUTE } },
 	{ KE_KEY, 17, { KEY_VOLUMEUP } },
 	{ KE_KEY, 18, { KEY_VOLUMEDOWN } },
 	{ KE_KEY, 19, { KEY_BRIGHTNESSUP } },
 	{ KE_KEY, 20, { KEY_BRIGHTNESSDOWN } },
 	/* 27: wake -- needs special handling */
 	{ KE_END },
 };

 /* 5 button array notification value. */
 static const struct key_entry intel_array_keymap[] = {
 	{ KE_KEY,    0xC2, { KEY_LEFTMETA } },                /* Press */
 	{ KE_IGNORE, 0xC3, { KEY_LEFTMETA } },                /* Release */
 	{ KE_KEY,    0xC4, { KEY_VOLUMEUP } },                /* Press */
 	{ KE_IGNORE, 0xC5, { KEY_VOLUMEUP } },                /* Release */
 	{ KE_KEY,    0xC6, { KEY_VOLUMEDOWN } },              /* Press */
 	{ KE_IGNORE, 0xC7, { KEY_VOLUMEDOWN } },              /* Release */
 	{ KE_KEY,    0xC8, { KEY_ROTATE_LOCK_TOGGLE } },      /* Press */
 	{ KE_IGNORE, 0xC9, { KEY_ROTATE_LOCK_TOGGLE } },      /* Release */
 	{ KE_KEY,    0xCE, { KEY_POWER } },                   /* Press */
 	{ KE_IGNORE, 0xCF, { KEY_POWER } },                   /* Release */
 	{ KE_END },
 };

 static const struct dmi_system_id button_array_table[] = {
 	{
 		.ident = "Wacom MobileStudio Pro 13",
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "Wacom Co.,Ltd"),
 			DMI_MATCH(DMI_PRODUCT_NAME, "Wacom MobileStudio Pro 13"),
 		},
 	},
 	{
 		.ident = "Wacom MobileStudio Pro 16",
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "Wacom Co.,Ltd"),
 			DMI_MATCH(DMI_PRODUCT_NAME, "Wacom MobileStudio Pro 16"),
 		},
 	},
 	{ }
 };

 struct intel_hid_priv {
 	struct input_dev *input_dev;
 	struct input_dev *array;
 	bool wakeup_mode;
 };

 #define HID_EVENT_FILTER_UUID	"eeec56b3-4442-408f-a792-4edd4d758054"

 enum intel_hid_dsm_fn_codes {
 	INTEL_HID_DSM_FN_INVALID,
 	INTEL_HID_DSM_BTNL_FN,
 	INTEL_HID_DSM_HDMM_FN,
 	INTEL_HID_DSM_HDSM_FN,
 	INTEL_HID_DSM_HDEM_FN,
 	INTEL_HID_DSM_BTNS_FN,
 	INTEL_HID_DSM_BTNE_FN,
 	INTEL_HID_DSM_HEBC_V1_FN,
 	INTEL_HID_DSM_VGBS_FN,
 	INTEL_HID_DSM_HEBC_V2_FN,
 	INTEL_HID_DSM_FN_MAX
 };

 static const char *intel_hid_dsm_fn_to_method[INTEL_HID_DSM_FN_MAX] = {
 	NULL,
 	"BTNL",
 	"HDMM",
 	"HDSM",
 	"HDEM",
 	"BTNS",
 	"BTNE",
 	"HEBC",
 	"VGBS",
 	"HEBC"
 };

 static unsigned long long intel_hid_dsm_fn_mask;
 static guid_t intel_dsm_guid;

 static bool intel_hid_execute_method(acpi_handle handle,
 				     enum intel_hid_dsm_fn_codes fn_index,
 				     unsigned long long arg)
 {
 	union acpi_object *obj, argv4, req;
 	acpi_status status;
 	char *method_name;

 	if (fn_index <= INTEL_HID_DSM_FN_INVALID ||
 	    fn_index >= INTEL_HID_DSM_FN_MAX)
 		return false;

 	method_name = (char *)intel_hid_dsm_fn_to_method[fn_index];

 	if (!(intel_hid_dsm_fn_mask & fn_index))
 		goto skip_dsm_exec;

 	/* All methods expects a package with one integer element */
 	req.type = ACPI_TYPE_INTEGER;
 	req.integer.value = arg;

 	argv4.type = ACPI_TYPE_PACKAGE;
 	argv4.package.count = 1;
 	argv4.package.elements = &req;

 	obj = acpi_evaluate_dsm(handle, &intel_dsm_guid, 1, fn_index, &argv4);
 	if (obj) {
 		acpi_handle_debug(handle, "Exec DSM Fn code: %d[%s] success\n",
 				  fn_index, method_name);
 		ACPI_FREE(obj);
 		return true;
 	}

 skip_dsm_exec:
 	status = acpi_execute_simple_method(handle, method_name, arg);
 	if (ACPI_SUCCESS(status))
 		return true;

 	return false;
 }

 static bool intel_hid_evaluate_method(acpi_handle handle,
 				      enum intel_hid_dsm_fn_codes fn_index,
 				      unsigned long long *result)
 {
 	union acpi_object *obj;
 	acpi_status status;
 	char *method_name;

 	if (fn_index <= INTEL_HID_DSM_FN_INVALID ||
 	    fn_index >= INTEL_HID_DSM_FN_MAX)
 		return false;

 	method_name = (char *)intel_hid_dsm_fn_to_method[fn_index];

 	if (!(intel_hid_dsm_fn_mask & fn_index))
 		goto skip_dsm_eval;

 	obj = acpi_evaluate_dsm_typed(handle, &intel_dsm_guid,
 				      1, fn_index,
 				      NULL,  ACPI_TYPE_INTEGER);
 	if (obj) {
 		*result = obj->integer.value;
 		acpi_handle_debug(handle,
 				  "Eval DSM Fn code: %d[%s] results: 0x%llx\n",
 				  fn_index, method_name, *result);
 		ACPI_FREE(obj);
 		return true;
 	}

 skip_dsm_eval:
 	status = acpi_evaluate_integer(handle, method_name, NULL, result);
 	if (ACPI_SUCCESS(status))
 		return true;

 	return false;
 }

 static void intel_hid_init_dsm(acpi_handle handle)
 {
 	union acpi_object *obj;

 	guid_parse(HID_EVENT_FILTER_UUID, &intel_dsm_guid);

 	obj = acpi_evaluate_dsm_typed(handle, &intel_dsm_guid, 1, 0, NULL,
 				      ACPI_TYPE_BUFFER);
 	if (obj) {
 		intel_hid_dsm_fn_mask = *obj->buffer.pointer;
 		ACPI_FREE(obj);
 	}

 	acpi_handle_debug(handle, "intel_hid_dsm_fn_mask = %llx\n",
 			  intel_hid_dsm_fn_mask);
 }

 static int intel_hid_set_enable(struct device *device, bool enable)
 {
 	acpi_handle handle = ACPI_HANDLE(device);

 	/* Enable|disable features - power button is always enabled */
 	if (!intel_hid_execute_method(handle, INTEL_HID_DSM_HDSM_FN,
 				      enable)) {
 		dev_warn(device, "failed to %sable hotkeys\n",
 			 enable ? "en" : "dis");
 		return -EIO;
 	}

 	return 0;
 }

 static void intel_button_array_enable(struct device *device, bool enable)
 {
 	struct intel_hid_priv *priv = dev_get_drvdata(device);
 	acpi_handle handle = ACPI_HANDLE(device);
 	unsigned long long button_cap;
 	acpi_status status;

 	if (!priv->array)
 		return;

 	/* Query supported platform features */
 	status = acpi_evaluate_integer(handle, "BTNC", NULL, &button_cap);
 	if (ACPI_FAILURE(status)) {
 		dev_warn(device, "failed to get button capability\n");
 		return;
 	}

 	/* Enable|disable features - power button is always enabled */
 	if (!intel_hid_execute_method(handle, INTEL_HID_DSM_BTNE_FN,
 				      enable ? button_cap : 1))
 		dev_warn(device, "failed to set button capability\n");
 }

 static int intel_hid_pm_prepare(struct device *device)
 {
 	struct intel_hid_priv *priv = dev_get_drvdata(device);

 	priv->wakeup_mode = true;
 	return 0;
 }

 static int intel_hid_pl_suspend_handler(struct device *device)
 {
 	if (pm_suspend_via_firmware()) {
 		intel_hid_set_enable(device, false);
 		intel_button_array_enable(device, false);
 	}
 	return 0;
 }

 static int intel_hid_pl_resume_handler(struct device *device)
 {
 	struct intel_hid_priv *priv = dev_get_drvdata(device);

 	priv->wakeup_mode = false;
 	if (pm_resume_via_firmware()) {
 		intel_hid_set_enable(device, true);
 		intel_button_array_enable(device, true);
 	}
 	return 0;
 }

 static const struct dev_pm_ops intel_hid_pl_pm_ops = {
 	.prepare = intel_hid_pm_prepare,
 	.freeze  = intel_hid_pl_suspend_handler,
 	.thaw  = intel_hid_pl_resume_handler,
 	.restore  = intel_hid_pl_resume_handler,
 	.suspend  = intel_hid_pl_suspend_handler,
 	.resume  = intel_hid_pl_resume_handler,
 };

 static int intel_hid_input_setup(struct platform_device *device)
 {
 	struct intel_hid_priv *priv = dev_get_drvdata(&device->dev);
 	int ret;

 	priv->input_dev = devm_input_allocate_device(&device->dev);
 	if (!priv->input_dev)
 		return -ENOMEM;

 	ret = sparse_keymap_setup(priv->input_dev, intel_hid_keymap, NULL);
 	if (ret)
 		return ret;

 	priv->input_dev->name = "Intel HID events";
 	priv->input_dev->id.bustype = BUS_HOST;

 	return input_register_device(priv->input_dev);
 }

 static int intel_button_array_input_setup(struct platform_device *device)
 {
 	struct intel_hid_priv *priv = dev_get_drvdata(&device->dev);
 	int ret;

 	/* Setup input device for 5 button array */
 	priv->array = devm_input_allocate_device(&device->dev);
 	if (!priv->array)
 		return -ENOMEM;

 	ret = sparse_keymap_setup(priv->array, intel_array_keymap, NULL);
 	if (ret)
 		return ret;

 	priv->array->name = "Intel HID 5 button array";
 	priv->array->id.bustype = BUS_HOST;

 	return input_register_device(priv->array);
 }

 static void notify_handler(acpi_handle handle, u32 event, void *context)
 {
 	struct platform_device *device = context;
 	struct intel_hid_priv *priv = dev_get_drvdata(&device->dev);
 	unsigned long long ev_index;

 	if (priv->wakeup_mode) {
 		/*
 		 * Needed for wakeup from suspend-to-idle to work on some
 		 * platforms that don't expose the 5-button array, but still
 		 * send notifies with the power button event code to this
 		 * device object on power button actions while suspended.
 		 */
 		if (event == 0xce)
 			goto wakeup;

 		/* Wake up on 5-button array events only. */
 		if (event == 0xc0 || !priv->array)
 			return;

 		if (!sparse_keymap_entry_from_scancode(priv->array, event)) {
 			dev_info(&device->dev, "unknown event 0x%x\n", event);
 			return;
 		}

 wakeup:
 		pm_wakeup_hard_event(&device->dev);
 		return;
 	}

 	/*
 	 * Needed for suspend to work on some platforms that don't expose
 	 * the 5-button array, but still send notifies with power button
 	 * event code to this device object on power button actions.
 	 *
 	 * Report the power button press and release.
 	 */
 	if (!priv->array) {
 		if (event == 0xce) {
 			input_report_key(priv->input_dev, KEY_POWER, 1);
 			input_sync(priv->input_dev);
 			return;
 		}

 		if (event == 0xcf) {
 			input_report_key(priv->input_dev, KEY_POWER, 0);
 			input_sync(priv->input_dev);
 			return;
 		}
 	}

 	/* 0xC0 is for HID events, other values are for 5 button array */
 	if (event != 0xc0) {
 		if (!priv->array ||
 		    !sparse_keymap_report_event(priv->array, event, 1, true))
 			dev_dbg(&device->dev, "unknown event 0x%x\n", event);
 		return;
 	}

 	if (!intel_hid_evaluate_method(handle, INTEL_HID_DSM_HDEM_FN,
 				       &ev_index)) {
 		dev_warn(&device->dev, "failed to get event index\n");
 		return;
 	}

 	if (!sparse_keymap_report_event(priv->input_dev, ev_index, 1, true))
 		dev_dbg(&device->dev, "unknown event index 0x%llx\n",
 			 ev_index);
 }

 static bool button_array_present(struct platform_device *device)
 {
 	acpi_handle handle = ACPI_HANDLE(&device->dev);
 	unsigned long long event_cap;

 	if (intel_hid_evaluate_method(handle, INTEL_HID_DSM_HEBC_V2_FN,
 				      &event_cap)) {
 		/* Check presence of 5 button array or v2 power button */
 		if (event_cap & 0x60000)
 			return true;
 	}

 	if (intel_hid_evaluate_method(handle, INTEL_HID_DSM_HEBC_V1_FN,
 				      &event_cap)) {
 		if (event_cap & 0x20000)
 			return true;
 	}

 	if (dmi_check_system(button_array_table))
 		return true;

 	return false;
 }

 static int intel_hid_probe(struct platform_device *device)
 {
 	acpi_handle handle = ACPI_HANDLE(&device->dev);
 	unsigned long long mode;
 	struct intel_hid_priv *priv;
 	acpi_status status;
 	int err;

 	intel_hid_init_dsm(handle);

 	if (!intel_hid_evaluate_method(handle, INTEL_HID_DSM_HDMM_FN, &mode)) {
 		dev_warn(&device->dev, "failed to read mode\n");
 		return -ENODEV;
 	}

 	if (mode != 0) {
 		/*
 		 * This driver only implements "simple" mode.  There appear
 		 * to be no other modes, but we should be paranoid and check
 		 * for compatibility.
 		 */
 		dev_info(&device->dev, "platform is not in simple mode\n");
 		return -ENODEV;
 	}

 	priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
 	dev_set_drvdata(&device->dev, priv);

 	err = intel_hid_input_setup(device);
 	if (err) {
 		pr_err("Failed to setup Intel HID hotkeys\n");
 		return err;
 	}

 	/* Setup 5 button array */
 	if (button_array_present(device)) {
 		dev_info(&device->dev, "platform supports 5 button array\n");
 		err = intel_button_array_input_setup(device);
 		if (err)
 			pr_err("Failed to setup Intel 5 button array hotkeys\n");
 	}

 	status = acpi_install_notify_handler(handle,
 					     ACPI_DEVICE_NOTIFY,
 					     notify_handler,
 					     device);
 	if (ACPI_FAILURE(status))
 		return -EBUSY;

 	err = intel_hid_set_enable(&device->dev, true);
 	if (err)
 		goto err_remove_notify;

 	if (priv->array) {
 		unsigned long long dummy;

 		intel_button_array_enable(&device->dev, true);

 		/* Call button load method to enable HID power button */
 		if (!intel_hid_evaluate_method(handle, INTEL_HID_DSM_BTNL_FN,
 					       &dummy)) {
 			dev_warn(&device->dev,
 				 "failed to enable HID power button\n");
 		}
 	}

 	device_init_wakeup(&device->dev, true);
 	return 0;

 err_remove_notify:
 	acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);

 	return err;
 }

 static int intel_hid_remove(struct platform_device *device)
 {
 	acpi_handle handle = ACPI_HANDLE(&device->dev);

 	device_init_wakeup(&device->dev, false);
 	acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
 	intel_hid_set_enable(&device->dev, false);
 	intel_button_array_enable(&device->dev, false);

 	/*
 	 * Even if we failed to shut off the event stream, we can still
 	 * safely detach from the device.
 	 */
 	return 0;
 }

 static struct platform_driver intel_hid_pl_driver = {
 	.driver = {
 		.name = "intel-hid",
 		.acpi_match_table = intel_hid_ids,
 		.pm = &intel_hid_pl_pm_ops,
 	},
 	.probe = intel_hid_probe,
 	.remove = intel_hid_remove,
 };
 MODULE_DEVICE_TABLE(acpi, intel_hid_ids);

 /*
  * Unfortunately, some laptops provide a _HID="INT33D5" device with
  * _CID="PNP0C02".  This causes the pnpacpi scan driver to claim the
  * ACPI node, so no platform device will be created.  The pnpacpi
  * driver rejects this device in subsequent processing, so no physical
  * node is created at all.
  *
  * As a workaround until the ACPI core figures out how to handle
  * this corner case, manually ask the ACPI platform device code to
  * claim the ACPI node.
  */
 static acpi_status __init
 check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
 {
 	const struct acpi_device_id *ids = context;
 	struct acpi_device *dev;

 	if (acpi_bus_get_device(handle, &dev) != 0)
 		return AE_OK;

 	if (acpi_match_device_ids(dev, ids) == 0)
 		if (acpi_create_platform_device(dev, NULL))
 			dev_info(&dev->dev,
 				 "intel-hid: created platform device\n");

 	return AE_OK;
 }

 static int __init intel_hid_init(void)
 {
 	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 			    ACPI_UINT32_MAX, check_acpi_dev, NULL,
 			    (void *)intel_hid_ids, NULL);

 	return platform_driver_register(&intel_hid_pl_driver);
 }
 module_init(intel_hid_init);

 static void __exit intel_hid_exit(void)
 {
 	platform_driver_unregister(&intel_hid_pl_driver);
 }
 module_exit(intel_hid_exit);
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Intel HID event & 5 button array driver
	*
	* Copyright (C) 2015 Alex Hung <[email protected]>
	* Copyright (C) 2015 Andrew Lutomirski <[email protected]>
	*/

	#include <linux/acpi.h>
	#include <linux/dmi.h>
	#include <linux/input.h>
	#include <linux/input/sparse-keymap.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/suspend.h>

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Alex Hung");

	static const struct acpi_device_id intel_hid_ids[] = {
	{"INT33D5", 0},
	{"", 0},
	};

	/* In theory, these are HID usages. */
	static const struct key_entry intel_hid_keymap[] = {
	/* 1: LSuper (Page 0x07, usage 0xE3) -- unclear what to do */
	/* 2: Toggle SW_ROTATE_LOCK -- easy to implement if seen in wild */
	{ KE_KEY, 3, { KEY_NUMLOCK } },
	{ KE_KEY, 4, { KEY_HOME } },
	{ KE_KEY, 5, { KEY_END } },
	{ KE_KEY, 6, { KEY_PAGEUP } },
	{ KE_KEY, 7, { KEY_PAGEDOWN } },
	{ KE_KEY, 8, { KEY_RFKILL } },
	{ KE_KEY, 9, { KEY_POWER } },
	{ KE_KEY, 11, { KEY_SLEEP } },
	/* 13 has two different meanings in the spec -- ignore it. */
	{ KE_KEY, 14, { KEY_STOPCD } },
	{ KE_KEY, 15, { KEY_PLAYPAUSE } },
	{ KE_KEY, 16, { KEY_MUTE } },
	{ KE_KEY, 17, { KEY_VOLUMEUP } },
	{ KE_KEY, 18, { KEY_VOLUMEDOWN } },
	{ KE_KEY, 19, { KEY_BRIGHTNESSUP } },
	{ KE_KEY, 20, { KEY_BRIGHTNESSDOWN } },
	/* 27: wake -- needs special handling */
	{ KE_END },
	};

	/* 5 button array notification value. */
	static const struct key_entry intel_array_keymap[] = {
	{ KE_KEY, 0xC2, { KEY_LEFTMETA } }, /* Press */
	{ KE_IGNORE, 0xC3, { KEY_LEFTMETA } }, /* Release */
	{ KE_KEY, 0xC4, { KEY_VOLUMEUP } }, /* Press */
	{ KE_IGNORE, 0xC5, { KEY_VOLUMEUP } }, /* Release */
	{ KE_KEY, 0xC6, { KEY_VOLUMEDOWN } }, /* Press */
	{ KE_IGNORE, 0xC7, { KEY_VOLUMEDOWN } }, /* Release */
	{ KE_KEY, 0xC8, { KEY_ROTATE_LOCK_TOGGLE } }, /* Press */
	{ KE_IGNORE, 0xC9, { KEY_ROTATE_LOCK_TOGGLE } }, /* Release */
	{ KE_KEY, 0xCE, { KEY_POWER } }, /* Press */
	{ KE_IGNORE, 0xCF, { KEY_POWER } }, /* Release */
	{ KE_END },
	};

	static const struct dmi_system_id button_array_table[] = {
	{
	.ident = "Wacom MobileStudio Pro 13",
	.matches = {
	DMI_MATCH(DMI_SYS_VENDOR, "Wacom Co.,Ltd"),
	DMI_MATCH(DMI_PRODUCT_NAME, "Wacom MobileStudio Pro 13"),
	},
	},
	{
	.ident = "Wacom MobileStudio Pro 16",
	.matches = {
	DMI_MATCH(DMI_SYS_VENDOR, "Wacom Co.,Ltd"),
	DMI_MATCH(DMI_PRODUCT_NAME, "Wacom MobileStudio Pro 16"),
	},
	},
	{ }
	};

	struct intel_hid_priv {
	struct input_dev *input_dev;
	struct input_dev *array;
	bool wakeup_mode;
	};

	#define HID_EVENT_FILTER_UUID "eeec56b3-4442-408f-a792-4edd4d758054"

	enum intel_hid_dsm_fn_codes {
	INTEL_HID_DSM_FN_INVALID,
	INTEL_HID_DSM_BTNL_FN,
	INTEL_HID_DSM_HDMM_FN,
	INTEL_HID_DSM_HDSM_FN,
	INTEL_HID_DSM_HDEM_FN,
	INTEL_HID_DSM_BTNS_FN,
	INTEL_HID_DSM_BTNE_FN,
	INTEL_HID_DSM_HEBC_V1_FN,
	INTEL_HID_DSM_VGBS_FN,
	INTEL_HID_DSM_HEBC_V2_FN,
	INTEL_HID_DSM_FN_MAX
	};

	static const char *intel_hid_dsm_fn_to_method[INTEL_HID_DSM_FN_MAX] = {
	NULL,
	"BTNL",
	"HDMM",
	"HDSM",
	"HDEM",
	"BTNS",
	"BTNE",
	"HEBC",
	"VGBS",
	"HEBC"
	};

	static unsigned long long intel_hid_dsm_fn_mask;
	static guid_t intel_dsm_guid;

	static bool intel_hid_execute_method(acpi_handle handle,
	enum intel_hid_dsm_fn_codes fn_index,
	unsigned long long arg)
	{
	union acpi_object *obj, argv4, req;
	acpi_status status;
	char *method_name;

	if (fn_index <= INTEL_HID_DSM_FN_INVALID \|\|
	fn_index >= INTEL_HID_DSM_FN_MAX)
	return false;

	method_name = (char *)intel_hid_dsm_fn_to_method[fn_index];

	if (!(intel_hid_dsm_fn_mask & fn_index))
	goto skip_dsm_exec;

	/* All methods expects a package with one integer element */
	req.type = ACPI_TYPE_INTEGER;
	req.integer.value = arg;

	argv4.type = ACPI_TYPE_PACKAGE;
	argv4.package.count = 1;
	argv4.package.elements = &req;

	obj = acpi_evaluate_dsm(handle, &intel_dsm_guid, 1, fn_index, &argv4);
	if (obj) {
	acpi_handle_debug(handle, "Exec DSM Fn code: %d[%s] success\n",
	fn_index, method_name);
	ACPI_FREE(obj);
	return true;
	}

	skip_dsm_exec:
	status = acpi_execute_simple_method(handle, method_name, arg);
	if (ACPI_SUCCESS(status))
	return true;

	return false;
	}

	static bool intel_hid_evaluate_method(acpi_handle handle,
	enum intel_hid_dsm_fn_codes fn_index,
	unsigned long long *result)
	{
	union acpi_object *obj;
	acpi_status status;
	char *method_name;

	if (fn_index <= INTEL_HID_DSM_FN_INVALID \|\|
	fn_index >= INTEL_HID_DSM_FN_MAX)
	return false;

	method_name = (char *)intel_hid_dsm_fn_to_method[fn_index];

	if (!(intel_hid_dsm_fn_mask & fn_index))
	goto skip_dsm_eval;

	obj = acpi_evaluate_dsm_typed(handle, &intel_dsm_guid,
	1, fn_index,
	NULL, ACPI_TYPE_INTEGER);
	if (obj) {
	*result = obj->integer.value;
	acpi_handle_debug(handle,
	"Eval DSM Fn code: %d[%s] results: 0x%llx\n",
	fn_index, method_name, *result);
	ACPI_FREE(obj);
	return true;
	}

	skip_dsm_eval:
	status = acpi_evaluate_integer(handle, method_name, NULL, result);
	if (ACPI_SUCCESS(status))
	return true;

	return false;
	}

	static void intel_hid_init_dsm(acpi_handle handle)
	{
	union acpi_object *obj;

	guid_parse(HID_EVENT_FILTER_UUID, &intel_dsm_guid);

	obj = acpi_evaluate_dsm_typed(handle, &intel_dsm_guid, 1, 0, NULL,
	ACPI_TYPE_BUFFER);
	if (obj) {
	intel_hid_dsm_fn_mask = *obj->buffer.pointer;
	ACPI_FREE(obj);
	}

	acpi_handle_debug(handle, "intel_hid_dsm_fn_mask = %llx\n",
	intel_hid_dsm_fn_mask);
	}

	static int intel_hid_set_enable(struct device *device, bool enable)
	{
	acpi_handle handle = ACPI_HANDLE(device);

	/* Enable\|disable features - power button is always enabled */
	if (!intel_hid_execute_method(handle, INTEL_HID_DSM_HDSM_FN,
	enable)) {
	dev_warn(device, "failed to %sable hotkeys\n",
	enable ? "en" : "dis");
	return -EIO;
	}

	return 0;
	}

	static void intel_button_array_enable(struct device *device, bool enable)
	{
	struct intel_hid_priv *priv = dev_get_drvdata(device);
	acpi_handle handle = ACPI_HANDLE(device);
	unsigned long long button_cap;
	acpi_status status;

	if (!priv->array)
	return;

	/* Query supported platform features */
	status = acpi_evaluate_integer(handle, "BTNC", NULL, &button_cap);
	if (ACPI_FAILURE(status)) {
	dev_warn(device, "failed to get button capability\n");
	return;
	}

	/* Enable\|disable features - power button is always enabled */
	if (!intel_hid_execute_method(handle, INTEL_HID_DSM_BTNE_FN,
	enable ? button_cap : 1))
	dev_warn(device, "failed to set button capability\n");
	}

	static int intel_hid_pm_prepare(struct device *device)
	{
	struct intel_hid_priv *priv = dev_get_drvdata(device);

	priv->wakeup_mode = true;
	return 0;
	}

	static int intel_hid_pl_suspend_handler(struct device *device)
	{
	if (pm_suspend_via_firmware()) {
	intel_hid_set_enable(device, false);
	intel_button_array_enable(device, false);
	}
	return 0;
	}

	static int intel_hid_pl_resume_handler(struct device *device)
	{
	struct intel_hid_priv *priv = dev_get_drvdata(device);

	priv->wakeup_mode = false;
	if (pm_resume_via_firmware()) {
	intel_hid_set_enable(device, true);
	intel_button_array_enable(device, true);
	}
	return 0;
	}

	static const struct dev_pm_ops intel_hid_pl_pm_ops = {
	.prepare = intel_hid_pm_prepare,
	.freeze = intel_hid_pl_suspend_handler,
	.thaw = intel_hid_pl_resume_handler,
	.restore = intel_hid_pl_resume_handler,
	.suspend = intel_hid_pl_suspend_handler,
	.resume = intel_hid_pl_resume_handler,
	};

	static int intel_hid_input_setup(struct platform_device *device)
	{
	struct intel_hid_priv *priv = dev_get_drvdata(&device->dev);
	int ret;

	priv->input_dev = devm_input_allocate_device(&device->dev);
	if (!priv->input_dev)
	return -ENOMEM;

	ret = sparse_keymap_setup(priv->input_dev, intel_hid_keymap, NULL);
	if (ret)
	return ret;

	priv->input_dev->name = "Intel HID events";
	priv->input_dev->id.bustype = BUS_HOST;

	return input_register_device(priv->input_dev);
	}

	static int intel_button_array_input_setup(struct platform_device *device)
	{
	struct intel_hid_priv *priv = dev_get_drvdata(&device->dev);
	int ret;

	/* Setup input device for 5 button array */
	priv->array = devm_input_allocate_device(&device->dev);
	if (!priv->array)
	return -ENOMEM;

	ret = sparse_keymap_setup(priv->array, intel_array_keymap, NULL);
	if (ret)
	return ret;

	priv->array->name = "Intel HID 5 button array";
	priv->array->id.bustype = BUS_HOST;

	return input_register_device(priv->array);
	}

	static void notify_handler(acpi_handle handle, u32 event, void *context)
	{
	struct platform_device *device = context;
	struct intel_hid_priv *priv = dev_get_drvdata(&device->dev);
	unsigned long long ev_index;

	if (priv->wakeup_mode) {
	/*
	* Needed for wakeup from suspend-to-idle to work on some
	* platforms that don't expose the 5-button array, but still
	* send notifies with the power button event code to this
	* device object on power button actions while suspended.
	*/
	if (event == 0xce)
	goto wakeup;

	/* Wake up on 5-button array events only. */
	if (event == 0xc0 \|\| !priv->array)
	return;

	if (!sparse_keymap_entry_from_scancode(priv->array, event)) {
	dev_info(&device->dev, "unknown event 0x%x\n", event);
	return;
	}

	wakeup:
	pm_wakeup_hard_event(&device->dev);
	return;
	}

	/*
	* Needed for suspend to work on some platforms that don't expose
	* the 5-button array, but still send notifies with power button
	* event code to this device object on power button actions.
	*
	* Report the power button press and release.
	*/
	if (!priv->array) {
	if (event == 0xce) {
	input_report_key(priv->input_dev, KEY_POWER, 1);
	input_sync(priv->input_dev);
	return;
	}

	if (event == 0xcf) {
	input_report_key(priv->input_dev, KEY_POWER, 0);
	input_sync(priv->input_dev);
	return;
	}
	}

	/* 0xC0 is for HID events, other values are for 5 button array */
	if (event != 0xc0) {
	if (!priv->array \|\|
	!sparse_keymap_report_event(priv->array, event, 1, true))
	dev_dbg(&device->dev, "unknown event 0x%x\n", event);
	return;
	}

	if (!intel_hid_evaluate_method(handle, INTEL_HID_DSM_HDEM_FN,
	&ev_index)) {
	dev_warn(&device->dev, "failed to get event index\n");
	return;
	}

	if (!sparse_keymap_report_event(priv->input_dev, ev_index, 1, true))
	dev_dbg(&device->dev, "unknown event index 0x%llx\n",
	ev_index);
	}

	static bool button_array_present(struct platform_device *device)
	{
	acpi_handle handle = ACPI_HANDLE(&device->dev);
	unsigned long long event_cap;

	if (intel_hid_evaluate_method(handle, INTEL_HID_DSM_HEBC_V2_FN,
	&event_cap)) {
	/* Check presence of 5 button array or v2 power button */
	if (event_cap & 0x60000)
	return true;
	}

	if (intel_hid_evaluate_method(handle, INTEL_HID_DSM_HEBC_V1_FN,
	&event_cap)) {
	if (event_cap & 0x20000)
	return true;
	}

	if (dmi_check_system(button_array_table))
	return true;

	return false;
	}

	static int intel_hid_probe(struct platform_device *device)
	{
	acpi_handle handle = ACPI_HANDLE(&device->dev);
	unsigned long long mode;
	struct intel_hid_priv *priv;
	acpi_status status;
	int err;

	intel_hid_init_dsm(handle);

	if (!intel_hid_evaluate_method(handle, INTEL_HID_DSM_HDMM_FN, &mode)) {
	dev_warn(&device->dev, "failed to read mode\n");
	return -ENODEV;
	}

	if (mode != 0) {
	/*
	* This driver only implements "simple" mode. There appear
	* to be no other modes, but we should be paranoid and check
	* for compatibility.
	*/
	dev_info(&device->dev, "platform is not in simple mode\n");
	return -ENODEV;
	}

	priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
	return -ENOMEM;
	dev_set_drvdata(&device->dev, priv);

	err = intel_hid_input_setup(device);
	if (err) {
	pr_err("Failed to setup Intel HID hotkeys\n");
	return err;
	}

	/* Setup 5 button array */
	if (button_array_present(device)) {
	dev_info(&device->dev, "platform supports 5 button array\n");
	err = intel_button_array_input_setup(device);
	if (err)
	pr_err("Failed to setup Intel 5 button array hotkeys\n");
	}

	status = acpi_install_notify_handler(handle,
	ACPI_DEVICE_NOTIFY,
	notify_handler,
	device);
	if (ACPI_FAILURE(status))
	return -EBUSY;

	err = intel_hid_set_enable(&device->dev, true);
	if (err)
	goto err_remove_notify;

	if (priv->array) {
	unsigned long long dummy;

	intel_button_array_enable(&device->dev, true);

	/* Call button load method to enable HID power button */
	if (!intel_hid_evaluate_method(handle, INTEL_HID_DSM_BTNL_FN,
	&dummy)) {
	dev_warn(&device->dev,
	"failed to enable HID power button\n");
	}
	}

	device_init_wakeup(&device->dev, true);
	return 0;

	err_remove_notify:
	acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);

	return err;
	}

	static int intel_hid_remove(struct platform_device *device)
	{
	acpi_handle handle = ACPI_HANDLE(&device->dev);

	device_init_wakeup(&device->dev, false);
	acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
	intel_hid_set_enable(&device->dev, false);
	intel_button_array_enable(&device->dev, false);

	/*
	* Even if we failed to shut off the event stream, we can still
	* safely detach from the device.
	*/
	return 0;
	}

	static struct platform_driver intel_hid_pl_driver = {
	.driver = {
	.name = "intel-hid",
	.acpi_match_table = intel_hid_ids,
	.pm = &intel_hid_pl_pm_ops,
	},
	.probe = intel_hid_probe,
	.remove = intel_hid_remove,
	};
	MODULE_DEVICE_TABLE(acpi, intel_hid_ids);

	/*
	* Unfortunately, some laptops provide a _HID="INT33D5" device with
	* _CID="PNP0C02". This causes the pnpacpi scan driver to claim the
	* ACPI node, so no platform device will be created. The pnpacpi
	* driver rejects this device in subsequent processing, so no physical
	* node is created at all.
	*
	* As a workaround until the ACPI core figures out how to handle
	* this corner case, manually ask the ACPI platform device code to
	* claim the ACPI node.
	*/
	static acpi_status __init
	check_acpi_dev(acpi_handle handle, u32 lvl, void context, void *rv)
	{
	const struct acpi_device_id *ids = context;
	struct acpi_device *dev;

	if (acpi_bus_get_device(handle, &dev) != 0)
	return AE_OK;

	if (acpi_match_device_ids(dev, ids) == 0)
	if (acpi_create_platform_device(dev, NULL))
	dev_info(&dev->dev,
	"intel-hid: created platform device\n");

	return AE_OK;
	}

	static int __init intel_hid_init(void)
	{
	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
	ACPI_UINT32_MAX, check_acpi_dev, NULL,
	(void *)intel_hid_ids, NULL);

	return platform_driver_register(&intel_hid_pl_driver);
	}
	module_init(intel_hid_init);

	static void __exit intel_hid_exit(void)
	{
	platform_driver_unregister(&intel_hid_pl_driver);
	}
	module_exit(intel_hid_exit);