LGE HotKey driver

lge-laptop.c

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/input/sparse-keymap.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/leds.h>
#include <linux/acpi.h>

#define LGE_WMI_KEY_EVENT_GUID "E4FB94F9-7F2B-4173-AD1A-CD1D95086248"
#define LGE_WMI_TMP_EVENT_GUID "023B133E-49D1-4E10-B313-698220140DC2"
#define LGE_WMI_MIS_EVENT_GUID "37BE1AC0-C3F2-4B1F-BFBE-8FDEAF2814D6"

#define LGE_WMI_GUID1 "C3A72B38-D3EF-42D3-8CBB-D5A57049F66D"
#define LGE_WMI_GUID2 "4E5C4404-3CED-4A5E-8C7A-1BA875D00A43"
#define LGE_WMI_GUID3 "2B4F501A-BD3C-4394-8DCF-00A7D2BC8210"

#define LGE_WMI_FILE "lge-wmi"
#define LGE_LAPTOP_NAME "LG Electronics Laptop Support"
#define LGE_LAPTOP_CLASS "LGE"
#define LGE_LAPTOP_FILE "lge-laptop"

#define LGE_AIRP_NAME "LGE Airplane Key driver"
#define LGE_AIRP_FILE "lge-airp"

#define LGE_WMI_GETULONG_METHODID 0x01
#define LGE_WMI_SETULONG_METHODID 0x02
#define LGE_WMI_FIREULONG_METHODID 0x03 /* unused */
#define LGE_WMI_IOULONG_METHODID 0x04 /* unused */

#define LGE_WMI_ERROR_INSTANCE_NOT_FOUND 0x80000001
#define LGE_WMI_ERROR_UNSUPPORTED_OPERATION 0x80000002
#define LGE_WMI_ERROR_INVALID_VALUE 0x80000003

#define LGE_EVBR 0x0140
#define LGE_EVWL 0x0136
#define LGE_EVFN 0x013B
#define LGE_EVDK 0x0148
#define LGE_EVPB 0x014B

MODULE_ALIAS("wmi:" LGE_WMI_KEY_EVENT_GUID);
MODULE_ALIAS("wmi:" LGE_WMI_TMP_EVENT_GUID);
MODULE_ALIAS("wmi:" LGE_WMI_MIS_EVENT_GUID);

static struct platform_device *lge_platform_device;
static struct input_dev *lge_wmi_inputdev;
static struct input_dev *lge_airp_inputdev;
static struct workqueue_struct *lge_touchpad_led_wq;
static struct work_struct lge_touchpad_led_work;
static int lge_touchpad_led_state;

static const struct key_entry lge_wmi_keymap[] = {
	{ KE_KEY, 112, { KEY_F13 } },
	{ KE_KEY, 116, { KEY_F21 } },
	{ KE_KEY, 151, { KEY_F14 } },
	{ KE_END, 0},
};

struct wmbb_buf_header {
	u32 req1;
	u16 req2;
	u16 unused;
	u32 result;
};

static int lge_wmab_execute(u8 instance, u32 method_id, u32 param, u32 *result)
{
	u32 tmp;
	struct acpi_buffer input = { sizeof(u32), &param };
	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
	acpi_status status;
	union acpi_object *obj;
	int retval = -EIO;

	status = wmi_evaluate_method(LGE_WMI_GUID1, instance, method_id, &input, &output);

	if (ACPI_FAILURE(status)) {
		printk(KERN_ERR pr_fmt("wmab execute failed: %x\n"), status);
		return retval;
	}

	obj = (union acpi_object *)output.pointer;
	if (!obj || obj->type != ACPI_TYPE_INTEGER)
		goto exit;

	tmp = (u32) obj->integer.value;
	if (tmp >= 0x80000000) {
		printk(KERN_ERR pr_fmt("wmab returned %x\n"), tmp);
		retval = -EIO;
		if (tmp == LGE_WMI_ERROR_INSTANCE_NOT_FOUND)
			retval = -ENXIO;
		if (tmp == LGE_WMI_ERROR_UNSUPPORTED_OPERATION)
			retval = -EPERM;
		if (tmp == LGE_WMI_ERROR_INVALID_VALUE)
			retval = -EINVAL;
	} else {
		retval = 0;
		if (result)
			*result = tmp;
	}

exit:
	kfree(obj);
	return retval;
}

static inline int lge_wmi_get_param(u8 instance, u32 *result) {
	return lge_wmab_execute(instance, LGE_WMI_GETULONG_METHODID, 0, result);
}

static inline int lge_wmi_set_param(u8 instance, u32 value) {
	return lge_wmab_execute(instance, LGE_WMI_SETULONG_METHODID, value, NULL);
}

static void lge_wmi_hotkey_notify(u32 event, void *context)
{
	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *obj;
	acpi_status status;
	u32 code;

	status = wmi_get_event_data(event, &response);
	if (ACPI_FAILURE(status)) {
		pr_err("bad event status %#x\n", status);
		return;
	}

	obj = (union acpi_object *)response.pointer;

	if (!obj || obj->type != ACPI_TYPE_INTEGER)
		goto exit;

	code = obj->integer.value;

	if (code <= 0xff) { /* FN key event (EVKY) */
		if (!sparse_keymap_report_event(lge_wmi_inputdev,
						code, 1, true))
			pr_info("Unknown key %x pressed\n", code);
		goto exit;
	}

	switch (code & 0xffff) {
	case LGE_EVBR:
	case LGE_EVWL:
	case LGE_EVFN:
	case LGE_EVDK:
	case LGE_EVPB:
	default:
		pr_info("event %x occured\n", code);
	}

exit:
	kfree(obj);
}

static enum led_brightness lge_wmi_touchpad_led_get(struct led_classdev *cdev)
{
	u32 res = 0xf;

	lge_wmi_get_param(0x30, &res);
	return (res & 0x2) ? LED_OFF : 1;
}

static void lge_wmi_touchpad_led_update(struct work_struct *work)
{
	u32 tmp;
	acpi_status status;

	status = lge_wmi_get_param(0x30, &tmp);
	if (ACPI_FAILURE(status))
		return;

	if (!(tmp & 0x2) != !!lge_touchpad_led_state)
		lge_wmi_set_param(0x30, tmp ^ 0x2); 
}

static void lge_wmi_touchpad_led_set(struct led_classdev *cdev,
	enum led_brightness value)
{
	lge_touchpad_led_state = (value > 0);
	queue_work(lge_touchpad_led_wq, &lge_touchpad_led_work);
}

static struct led_classdev touchpad_led = {
	.name = "lge-wmi::touchpad",
	.flags = 0,
	.max_brightness = 1,
	.brightness_get = lge_wmi_touchpad_led_get,
	.brightness_set = lge_wmi_touchpad_led_set,
};

static struct attribute *lge_attributes[] = {
	NULL
};

static const struct attribute_group lge_attr_group = {
	.is_visible = NULL,
	.attrs = lge_attributes,
};

static int lge_wmi_input_setup(struct platform_device *device)
{
	struct input_dev *inputdev;
	acpi_status status;
	int err;

	inputdev = input_allocate_device();
	if (!inputdev)
		return -ENOMEM;

	inputdev->name = "LG Electronics Laptop WMI hotkeys";
	inputdev->phys = LGE_WMI_FILE "/input0";
	inputdev->id.bustype = BUS_HOST;
	inputdev->dev.parent = &device->dev;

	err = sparse_keymap_setup(inputdev, lge_wmi_keymap, NULL);

	if (err)
		goto err_free_dev;

	status = wmi_install_notify_handler(LGE_WMI_KEY_EVENT_GUID,
						lge_wmi_hotkey_notify, NULL);
	if (ACPI_FAILURE(status)) {
		err = -EIO;
		goto err_free_keymap;
	}

	err = input_register_device(inputdev);
	if (err)
		goto err_uninstall_notifier;

	lge_wmi_inputdev = inputdev;
	return 0;

err_uninstall_notifier:
	wmi_remove_notify_handler(LGE_WMI_KEY_EVENT_GUID);
err_free_keymap:
	sparse_keymap_free(inputdev);
err_free_dev:
	input_free_device(inputdev);
	return err;
}

static void lge_wmi_input_destroy(void)
{
	if (lge_wmi_inputdev) {
		wmi_remove_notify_handler(LGE_WMI_KEY_EVENT_GUID);
		sparse_keymap_free(lge_wmi_inputdev);
		input_unregister_device(lge_wmi_inputdev);
	}
	lge_wmi_inputdev = NULL;
}

static int lge_airp_input_setup(struct platform_device *device)
{
	int err;

	lge_airp_inputdev = input_allocate_device();
	if (!lge_airp_inputdev)
		return -ENOMEM;
	
	lge_airp_inputdev->name = LGE_AIRP_NAME;
	lge_airp_inputdev->phys = LGE_AIRP_FILE "/input0";
	lge_airp_inputdev->id.bustype = BUS_HOST;
	lge_airp_inputdev->dev.parent = &device->dev;
	set_bit(EV_KEY, lge_airp_inputdev->evbit);
	set_bit(KEY_RFKILL, lge_airp_inputdev->keybit);

	err = input_register_device(lge_airp_inputdev);
	if (err) {
		input_free_device(lge_airp_inputdev);
		return err;
	}

	return 0;
}

static int lge_airp_input_destroy(struct platform_device *device)
{
	input_unregister_device(lge_airp_inputdev);
	return 0;
}

static void lge_airp_notify_handler(acpi_handle handle, u32 event, void *context)
{
	struct platform_device *device = context;

	if (event != 0x80) {
		dev_warn(&device->dev, "unknown event: %#x\n", event);
		return;
	}
	input_report_key(lge_airp_inputdev, KEY_RFKILL, 1);
	input_report_key(lge_airp_inputdev, KEY_RFKILL, 0);
	input_sync(lge_airp_inputdev);
}

static int lge_airp_probe(struct platform_device *device)
{
	acpi_handle handle = ACPI_HANDLE(&device->dev);
	acpi_status result;
	u64 dev_status;
	int err;

	result = acpi_evaluate_integer(handle, "_STA", NULL, &dev_status);
	if (!(result == AE_NOT_FOUND || (ACPI_SUCCESS(result) && (dev_status & 0x1f) != 0))) {
		dev_warn(&device->dev, "Either LGE Airplane Key is not present or OSI configuration is inappropriate\n");
		return -ENODEV;
	}

	err = lge_airp_input_setup(device);
	if (err) {
		pr_err("Failed to set up LGE Airplane Key\n");
		return err;
	}

	result = acpi_install_notify_handler(handle,
					     ACPI_DEVICE_NOTIFY,
					     lge_airp_notify_handler,
					     device);
	if (ACPI_FAILURE(result)) {
		err = -EBUSY;
		goto err_remove_input;
	}

	return 0;

err_remove_input:
	lge_airp_input_destroy(device);

	return err;
}

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

	lge_airp_input_destroy(device);
	acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, lge_airp_notify_handler);

	return 0;
}

static const struct acpi_device_id lge_airp_ids[] = {
	{"LGEX0815", 0},
	{"", 0},
};

static struct platform_driver lge_airp_pl_driver = {
	.driver = {
		.name = "lge-airp",
		.acpi_match_table = lge_airp_ids,
	},
	.probe = lge_airp_probe,
	.remove = lge_airp_remove,
};
MODULE_DEVICE_TABLE(acpi, lge_airp_ids);

static int lge_wmi_platform_probe(struct platform_device *device)
{
	int err;

	if (wmi_has_guid(LGE_WMI_KEY_EVENT_GUID)) {
		err = lge_wmi_input_setup(device);
		if (err)
			goto fail_input_setup;
	}

	if (wmi_has_guid(LGE_WMI_GUID1)) {
		lge_touchpad_led_wq =
			create_singlethread_workqueue("lge_touchpad_workqueue");
		if (!lge_touchpad_led_wq) {
			err = -ENOMEM;
			goto fail_create_touchpad_wq;
		}
		INIT_WORK(&lge_touchpad_led_work, lge_wmi_touchpad_led_update);

		touchpad_led.brightness = 1;
		err = devm_led_classdev_register(&device->dev, &touchpad_led);
		if (err)
			goto fail_create_touchpad_led;
	}

	err = sysfs_create_group(&device->dev.kobj, &lge_attr_group);
	if (err)
		goto fail_sysfs;
	return 0;

fail_sysfs:
	devm_led_classdev_unregister(&device->dev, &touchpad_led);

fail_create_touchpad_led:
	destroy_workqueue(lge_touchpad_led_wq);

fail_create_touchpad_wq:
	lge_wmi_input_destroy();

fail_input_setup:
	return err;
}

static int lge_wmi_platform_remove(struct platform_device *device)
{
	sysfs_remove_group(&device->dev.kobj, &lge_attr_group);
	devm_led_classdev_unregister(&device->dev, &touchpad_led);
	destroy_workqueue(lge_touchpad_led_wq);
	lge_wmi_input_destroy();
	return 0;
}

static struct platform_driver lge_platform_driver = {
	.driver = {
		.name = LGE_LAPTOP_FILE,
	},
	.remove = lge_wmi_platform_remove,
};

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, "created platform device");
	
	return AE_OK;
}

static int lge_wmi_enabled = 0, lge_airp_enabled = 0;

static int __init lge_wmi_init(void)
{
	if (!wmi_has_guid(LGE_WMI_GUID1)) {
		return -ENODEV;
	}

	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
			    ACPI_UINT32_MAX, check_acpi_dev, NULL,
			    (void *)lge_airp_ids, NULL);

	lge_platform_device = platform_create_bundle(&lge_platform_driver,
						    lge_wmi_platform_probe,
						    NULL, 0, NULL, 0);
	lge_wmi_enabled = !IS_ERR(lge_platform_device);

	lge_airp_enabled = !platform_driver_register(&lge_airp_pl_driver);

	if (!lge_wmi_enabled && !lge_airp_enabled)
		return -ENODEV;

	return 0;
}

void lge_wmi_exit(void)
{
	if (lge_airp_enabled)
		platform_driver_unregister(&lge_airp_pl_driver);

	if (lge_wmi_enabled) {
		platform_device_unregister(lge_platform_device);
		platform_driver_unregister(&lge_platform_driver);
	}
}

module_init(lge_wmi_init);
module_exit(lge_wmi_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jin-oh Kang <jinoh.kang.kr@gmail.com>");
MODULE_DESCRIPTION("some LG laptop stuff");