/*
* uniwill_keyboard.h
*
* Copyright (C) 2018-2020 TUXEDO Computers GmbH <tux@tuxedocomputers.com>
*
* 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 "tuxedo_keyboard_common.h"
#include <linux/acpi.h>
#include <linux/wmi.h>
#include <linux/workqueue.h>
#include <linux/keyboard.h>

#define UNIWILL_WMI_MGMT_GUID_BA "ABBC0F6D-8EA1-11D1-00A0-C90629100000"
#define UNIWILL_WMI_MGMT_GUID_BB "ABBC0F6E-8EA1-11D1-00A0-C90629100000"
#define UNIWILL_WMI_MGMT_GUID_BC "ABBC0F6F-8EA1-11D1-00A0-C90629100000"

#define UNIWILL_WMI_EVENT_GUID_0 "ABBC0F70-8EA1-11D1-00A0-C90629100000"
#define UNIWILL_WMI_EVENT_GUID_1 "ABBC0F71-8EA1-11D1-00A0-C90629100000"
#define UNIWILL_WMI_EVENT_GUID_2 "ABBC0F72-8EA1-11D1-00A0-C90629100000"

#define UNIWILL_OSD_RADIOON			0x01A
#define UNIWILL_OSD_RADIOOFF			0x01B

#define UNIWILL_OSD_TOUCHPADWORKAROUND		0xFFF

#define UNIWILL_BRIGHTNESS_MIN			0x00
#define UNIWILL_BRIGHTNESS_MAX			0xc8
#define UNIWILL_BRIGHTNESS_DEFAULT		UNIWILL_BRIGHTNESS_MAX * 0.75
#define UNIWILL_COLOR_DEFAULT			0xffffff
#define UNIWILL_COLOR_STRING_DEFAULT		"WHITE"

union uw_ec_read_return {
    u32 dword;
    struct {
        u8 data_low;
        u8 data_high;
    } bytes;
};

union uw_ec_write_return {
    u32 dword;
    struct {
        u8 addr_low;
        u8 addr_high;
        u8 data_low;
        u8 data_high;
    } bytes;
};

extern u32 uniwill_wmi_ec_read(u8, u8, union uw_ec_read_return *);
extern u32 uniwill_wmi_ec_write(u8, u8, u8, u8, union uw_ec_write_return *);

struct tuxedo_keyboard_driver uniwill_keyboard_driver;

struct kbd_led_state_uw_t {
	u32 brightness;
	u32 color;
	char color_string[COLOR_STRING_LEN];
} kbd_led_state_uw = {
	.brightness = UNIWILL_BRIGHTNESS_DEFAULT,
	.color = UNIWILL_COLOR_DEFAULT,
	.color_string = UNIWILL_COLOR_STRING_DEFAULT
};

static struct key_entry uniwill_wmi_keymap[] = {
	// { KE_KEY,	UNIWILL_OSD_RADIOON,		{ KEY_RFKILL } },
	// { KE_KEY,	UNIWILL_OSD_RADIOOFF,		{ KEY_RFKILL } },
	// { KE_KEY,	0xb0,				{ KEY_F13 } },
	{ KE_KEY,	UNIWILL_OSD_TOUCHPADWORKAROUND,	{ KEY_F21 } },
	// Only used to put ev bits
	{ KE_KEY,	0xffff,				{ KEY_F6 } },
	{ KE_KEY,	0xffff,				{ KEY_LEFTALT } },
	{ KE_KEY,	0xffff,				{ KEY_LEFTMETA } },
	{ KE_END,	0 }
};

static u8 uniwill_kbd_bl_enable_state_on_start;

static void key_event_work(struct work_struct *work)
{
	sparse_keymap_report_known_event(
		current_driver->input_device,
		UNIWILL_OSD_TOUCHPADWORKAROUND,
		1,
		true
	);
}

// Previous key codes for detecting longer combination
static u32 prev_key = 0, prevprev_key = 0;
static DECLARE_WORK(uniwill_key_event_work, key_event_work);

static int keyboard_notifier_callb(struct notifier_block *nb, unsigned long code, void *_param)
{
	struct keyboard_notifier_param *param = _param;
	int ret = NOTIFY_OK;

	if (!param->down) {

		if (code == KBD_KEYCODE) {
			switch (param->value) {
			case 125:
				// If the last keys up were 85 -> 29 -> 125
				// manually report KEY_F21
				if (prevprev_key == 85 && prev_key == 29) {
					TUXEDO_DEBUG("Touchpad Toggle\n");
					schedule_work(&uniwill_key_event_work);
					ret = NOTIFY_STOP;
				}
				break;
			}
			prevprev_key = prev_key;
			prev_key = param->value;
		}
	}

	return ret;
}

static struct notifier_block keyboard_notifier_block = {
    .notifier_call = keyboard_notifier_callb
};

static u8 uniwill_read_kbd_bl_enabled(void)
{
	union uw_ec_read_return reg_read_return;

	u32 (*__uniwill_wmi_ec_read)(u8, u8, union uw_ec_read_return *);

	u8 enabled = 0xff;

	__uniwill_wmi_ec_read = symbol_get(uniwill_wmi_ec_read);

	if (__uniwill_wmi_ec_read) {
		__uniwill_wmi_ec_read(0x8c, 0x07, &reg_read_return);
		enabled = (reg_read_return.bytes.data_low >> 1) & 0x01;
		enabled = !enabled;
	} else {
		TUXEDO_DEBUG("tuxedo-cc-wmi symbols not found\n");
	}

	if (__uniwill_wmi_ec_read) symbol_put(uniwill_wmi_ec_read);

	return enabled;
}

static void uniwill_write_kbd_bl_enable(u8 enable)
{
	union uw_ec_read_return reg_read_return;
	union uw_ec_write_return reg_write_return;

	u32 (*__uniwill_wmi_ec_read)(u8, u8, union uw_ec_read_return *);
	u32 (*__uniwill_wmi_ec_write)(u8, u8, u8, u8, union uw_ec_write_return *);

	u8 write_value = 0;
	enable = enable & 0x01;

	__uniwill_wmi_ec_read = symbol_get(uniwill_wmi_ec_read);
	__uniwill_wmi_ec_write = symbol_get(uniwill_wmi_ec_write);

	if (__uniwill_wmi_ec_read && __uniwill_wmi_ec_write) {
		__uniwill_wmi_ec_read(0x8c, 0x07, &reg_read_return);
		write_value = reg_read_return.bytes.data_low & ~(1 << 1);
		write_value |= (!enable << 1);
		__uniwill_wmi_ec_write(0x8c, 0x07, write_value, reg_read_return.bytes.data_high, &reg_write_return);
	} else {
		TUXEDO_DEBUG("tuxedo-cc-wmi symbols not found\n");
	}

	if (__uniwill_wmi_ec_read) symbol_put(uniwill_wmi_ec_read);
	if (__uniwill_wmi_ec_write) symbol_put(uniwill_wmi_ec_write);
}

static void uniwill_write_kbd_bl_rgb(u8 red, u8 green, u8 blue)
{
	union uw_ec_read_return reg_read_return;
	u8 high_byte_red_reg, high_byte_green_reg, high_byte_blue_reg;
	union uw_ec_write_return reg_write_return;

	u32 (*__uniwill_wmi_ec_read)(u8, u8, union uw_ec_read_return *);
	u32 (*__uniwill_wmi_ec_write)(u8, u8, u8, u8, union uw_ec_write_return *);

	__uniwill_wmi_ec_read = symbol_get(uniwill_wmi_ec_read);
	__uniwill_wmi_ec_write = symbol_get(uniwill_wmi_ec_write);

	if (__uniwill_wmi_ec_read && __uniwill_wmi_ec_write) {
		// Read high bytes to put the same values back
		__uniwill_wmi_ec_read(0x03, 0x18, &reg_read_return);
		high_byte_red_reg = reg_read_return.bytes.data_high;
		__uniwill_wmi_ec_read(0x05, 0x18, &reg_read_return);
		high_byte_green_reg = reg_read_return.bytes.data_high;
		__uniwill_wmi_ec_read(0x08, 0x18, &reg_read_return);
		high_byte_blue_reg = reg_read_return.bytes.data_high;

		// Write the colors
		// Note: Writing is done separately because of less delay than by reading
		// thereby making the transition smoother
		__uniwill_wmi_ec_write(0x03, 0x18, red, high_byte_red_reg, &reg_write_return);
		__uniwill_wmi_ec_write(0x05, 0x18, green, high_byte_green_reg, &reg_write_return);
		__uniwill_wmi_ec_write(0x08, 0x18, blue, high_byte_blue_reg, &reg_write_return);
	} else {
		TUXEDO_DEBUG("tuxedo-cc-wmi symbols not found\n");
	}

	if (__uniwill_wmi_ec_read) symbol_put(uniwill_wmi_ec_read);
	if (__uniwill_wmi_ec_write) symbol_put(uniwill_wmi_ec_write);
}

static void uniwill_write_kbd_bl_state(void) {
	// Get single colors from state
	u32 color_red = ((kbd_led_state_uw.color >> 0x10) & 0xff);
	u32 color_green = (kbd_led_state_uw.color >> 0x08) & 0xff;
	u32 color_blue = (kbd_led_state_uw.color >> 0x00) & 0xff;

	u32 brightness_percentage = (kbd_led_state_uw.brightness * 100) / UNIWILL_BRIGHTNESS_MAX;

	// Scale color values
	color_red = (color_red * 0xc8) / 0xff;
	color_green = (color_green * 0xc8) / 0xff;
	color_blue = (color_blue * 0xc8) / 0xff;

	// Scale the respective values
	color_red = (color_red * brightness_percentage) / 100;
	color_green = (color_green * brightness_percentage) / 100;
	color_blue = (color_blue * brightness_percentage) / 100;

	uniwill_write_kbd_bl_rgb(color_red, color_green, color_blue);
}

static void uniwill_wmi_handle_event(u32 value, void *context, u32 guid_nr)
{
	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *obj;

	acpi_status status;
	int code;

	status = wmi_get_event_data(value, &response);
	if (status != AE_OK) {
		TUXEDO_ERROR("uniwill handle event -> bad event status\n");
		return;
	}

	obj = (union acpi_object *) response.pointer;
	if (obj && obj->type == ACPI_TYPE_INTEGER) {
		code = obj->integer.value;
		if (!sparse_keymap_report_known_event(current_driver->input_device, code, 1, true)) {
			TUXEDO_DEBUG("[Ev %d] Unknown key - %d (%0#6x)\n", guid_nr, code, code);
		}

		// Special key combination when mode change key is pressed
		if (code == 0xb0) {
			input_report_key(current_driver->input_device, KEY_LEFTMETA, 1);
			input_report_key(current_driver->input_device, KEY_LEFTALT, 1);
			input_report_key(current_driver->input_device, KEY_F6, 1);
			input_sync(current_driver->input_device);
			input_report_key(current_driver->input_device, KEY_F6, 0);
			input_report_key(current_driver->input_device, KEY_LEFTALT, 0);
			input_report_key(current_driver->input_device, KEY_LEFTMETA, 0);
			input_sync(current_driver->input_device);
		}

		// Keyboard backlight brightness toggle
		switch (code) {
		case 0x3b:
			kbd_led_state_uw.brightness = 0x00;
			uniwill_write_kbd_bl_state();
			break;
		case 0x3c:
			kbd_led_state_uw.brightness = 0x20;
			uniwill_write_kbd_bl_state();
			break;
		case 0x3d:
			kbd_led_state_uw.brightness = 0x50;
			uniwill_write_kbd_bl_state();
			break;
		case 0x3e:
			kbd_led_state_uw.brightness = 0x80;
			uniwill_write_kbd_bl_state();
			break;
		case 0x3f:
			kbd_led_state_uw.brightness = 0xc8;
			uniwill_write_kbd_bl_state();
			break;
		}
	}

	kfree(obj);
}

static void uniwill_wmi_notify0(u32 value, void *context)
{
	uniwill_wmi_handle_event(value, context, 0);
}

static void uniwill_wmi_notify1(u32 value, void *context)
{
	uniwill_wmi_handle_event(value, context, 1);
}

static void uniwill_wmi_notify2(u32 value, void *context)
{
	uniwill_wmi_handle_event(value, context, 2);
}

static int uniwill_keyboard_probe(struct platform_device *dev)
{
	int status;

	// Look for for GUIDs used on uniwill devices
	status =
		wmi_has_guid(UNIWILL_WMI_EVENT_GUID_0) &&
		wmi_has_guid(UNIWILL_WMI_EVENT_GUID_1) &&
		wmi_has_guid(UNIWILL_WMI_EVENT_GUID_2) &&
		wmi_has_guid(UNIWILL_WMI_MGMT_GUID_BA) &&
		wmi_has_guid(UNIWILL_WMI_MGMT_GUID_BB) &&
		wmi_has_guid(UNIWILL_WMI_MGMT_GUID_BC);
	
	if (!status) {
		TUXEDO_DEBUG("probe: At least one Uniwill GUID missing\n");
		return -ENODEV;
	}

	// Attempt to add event handlers
	status = wmi_install_notify_handler(UNIWILL_WMI_EVENT_GUID_0, uniwill_wmi_notify0, NULL);
	if (ACPI_FAILURE(status)) {
		TUXEDO_ERROR("probe: Failed to install uniwill notify handler 0\n");
		goto err_remove_notifiers;
	}
	
	status = wmi_install_notify_handler(UNIWILL_WMI_EVENT_GUID_1, uniwill_wmi_notify1, NULL);
	if (ACPI_FAILURE(status)) {
		TUXEDO_ERROR("probe: Failed to install uniwill notify handler 1\n");
		goto err_remove_notifiers;
	}

	status = wmi_install_notify_handler(UNIWILL_WMI_EVENT_GUID_2, uniwill_wmi_notify2, NULL);
	if (ACPI_FAILURE(status)) {
		TUXEDO_ERROR("probe: Failed to install uniwill notify handler 2\n");
		goto err_remove_notifiers;
	}

	status = register_keyboard_notifier(&keyboard_notifier_block);

	// Save previous enable state
	uniwill_kbd_bl_enable_state_on_start = uniwill_read_kbd_bl_enabled();

	// Disable backlight while initializing
	uniwill_write_kbd_bl_enable(0);

	// Initialize keyboard backlight driver state according to parameters
	if (param_brightness > UNIWILL_BRIGHTNESS_MAX) param_brightness = UNIWILL_BRIGHTNESS_DEFAULT;
	kbd_led_state_uw.brightness = param_brightness;
	if (color_lookup(&color_list, param_color) <= (u32) 0xffffff) kbd_led_state_uw.color = color_lookup(&color_list, param_color);
	else kbd_led_state_uw.color = UNIWILL_COLOR_DEFAULT;

	// Update keyboard according to the current state
	uniwill_write_kbd_bl_state();

	// Enable keyboard backlight
	uniwill_write_kbd_bl_enable(1);

	return 0;

err_remove_notifiers:
	wmi_remove_notify_handler(UNIWILL_WMI_EVENT_GUID_0);
	wmi_remove_notify_handler(UNIWILL_WMI_EVENT_GUID_1);
	wmi_remove_notify_handler(UNIWILL_WMI_EVENT_GUID_2);

	return -ENODEV;
}

static int uniwill_keyboard_remove(struct platform_device *dev)
{
	// Restore previous backlight enable state
	if (uniwill_kbd_bl_enable_state_on_start != 0xff) {
		uniwill_write_kbd_bl_enable(uniwill_kbd_bl_enable_state_on_start);
	}

	unregister_keyboard_notifier(&keyboard_notifier_block);
	wmi_remove_notify_handler(UNIWILL_WMI_EVENT_GUID_0);
	wmi_remove_notify_handler(UNIWILL_WMI_EVENT_GUID_1);
	wmi_remove_notify_handler(UNIWILL_WMI_EVENT_GUID_2);

	return 0;
}

static int uniwill_keyboard_suspend(struct platform_device *dev, pm_message_t state)
{
	uniwill_write_kbd_bl_enable(0);
	return 0;
}

static int uniwill_keyboard_resume(struct platform_device *dev)
{
	uniwill_write_kbd_bl_state();
	uniwill_write_kbd_bl_enable(1);
	return 0;
}

static struct platform_driver platform_driver_uniwill = {
	.remove = uniwill_keyboard_remove,
	.suspend = uniwill_keyboard_suspend,
	.resume = uniwill_keyboard_resume,
	.driver =
		{
			.name = DRIVER_NAME,
			.owner = THIS_MODULE,
		},
};

struct tuxedo_keyboard_driver uniwill_keyboard_driver = {
	.platform_driver = &platform_driver_uniwill,
	.probe = uniwill_keyboard_probe,
	.key_map = uniwill_wmi_keymap,
};