/*
 * HID driver for Google Fiber TV remote controls
 *
 * Copyright (c) 2014 Google Inc.
 *
 * 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.
 */
#include <linux/device.h>
#include <linux/hid.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include "hid-ids.h"

#define GFRM100  1  /* Google Fiber GFRM100 (Bluetooth classic) */
#define GFRM200  2  /* Google Fiber GFRM200 (Bluetooth LE) */
#define TIARC    3  /* Texas Instruments CC2541ARC (Bluetooth LE) */

#define GFRM100_SEARCH_KEY_REPORT_ID   0xF7
#define GFRM100_SEARCH_KEY_DOWN        0x0
#define GFRM100_SEARCH_KEY_AUDIO_DATA  0x1
#define GFRM100_SEARCH_KEY_UP          0x2

static u8 search_key_dn[3] = {0x40, 0xF7, 0x00};
static u8 search_key_up[3] = {0x40, 0x00, 0x00};


static const char* rawEventToButton(u8* data, int size)
{
	int code = 0xffff, key = 0xffff;		// aka unset
	static char msg[128];

	if (size < 1) goto unknown;

	/* GFRM200: see "SRS_RC1534059_V0 11.pdf" */
	/* strings match vendor/broadcom/drivers/bt/3rdparty/embedded/brcm/linux/bthid/bthid.c */

	code = data[0];
	switch (code) {
	case 0x02:			// GFRM200 usage page 0x01, 0x06
		if (size != 9) goto unknown;
		key = data[3];
		switch (key) {
		case 0x00:    return "RELEASE2";
		case 0x1E:    return "DIGIT_1";
		case 0x1F:    return "DIGIT_2";
		case 0x20:    return "DIGIT_3";
		case 0x21:    return "DIGIT_4";
		case 0x22:    return "DIGIT_5";
		case 0x23:    return "DIGIT_6";
		case 0x24:    return "DIGIT_7";
		case 0x25:    return "DIGIT_8";
		case 0x26:    return "DIGIT_9";
		case 0x27:    return "DIGIT_0";
		case 0x28:    return "OK";
		case 0x4F:    return "RIGHT";
		case 0x50:    return "LEFT";
		case 0x51:    return "DOWN";
		case 0x52:    return "UP";
		}
		break;

	case 0x03:			// GFRM200 usage page 0x01, 0x0c
		if (size != 3) goto unknown;
		key = data[1] | (data[2] << 8);
		switch (key) {
		case 0x00:    return "RELEASE3";
		case 0x30:    return "TV_BOX_POWER";
		case 0x40:    return "MENU";
		case 0x4C:    return "DIGIT_DEL";
		case 0x63:    return "INPUT";
		case 0x7F:    return "TV_POWER";
		case 0x83:    return "BACK";
		case 0x8D:    return "GUIDE";
		case 0x94:    return "EXIT";
		case 0x95:    return "INFO";
		case 0x9C:    return "CH_UP";
		case 0x9D:    return "CH_DOWN";
		case 0xB0:    return "PLAY";
		case 0xB1:    return "PAUSE";
		case 0xB2:    return "RECORD";
		case 0xB3:    return "FAST_FORWARD";
		case 0xB4:    return "REWIND";
		case 0xB5:    return "SKIP_FORWARD";
		case 0xB6:    return "SKIP_BACKWARD";
		case 0xB7:    return "STOP";
		case 0xE2:    return "MUTE";
		case 0xE9:    return "VOL_UP";
		case 0xEA:    return "VOL_DOWN";
		case 0x221:   return "SEARCH";
		case 0x224:   return "PREV";
		}
		break;

	case 0x81:			// GFRM200 usage page 0xff, 0x00
		if (size != 2) goto unknown;
		key = data[1];
		switch (key) {
		case 0x00:    return "RELEASE81";
		case 0x01:    return "LIVE";
		}
		break;

	case 0x12:			// GFRM100 type 0x12
		if (size != 3) goto unknown;
		key = data[1];
		switch (key) {
		case 0x00:    return "RELEASE12";
		case 0x82:    return "TV_POWER";
		}
		break;

	case 0x13:			// GFRM100 type 0x13
		if (size != 2) goto unknown;
		key = data[1];
		sprintf(msg, "BATTERY_LEVEL=%d", key);	// percent 0-100?
		return msg;
		break;

	case 0x40:			// GFRM100 type 0x40
		if (size != 3) goto unknown;
		key = data[1] | (data[2] << 8);
		switch (key) {
		case 0x00:    return "RELEASE40";
		case 0x04:    return "INFO";
		case 0x41:    return "OK";
		case 0x42:    return "UP";
		case 0x43:    return "DOWN";
		case 0x44:    return "LEFT";
		case 0x45:    return "RIGHT";
		case 0x30:    return "TV_BOX_POWER";
		case 0x40:    return "MENU";
		case 0x82:    return "INPUT";
		case 0x83:    return "PREV";
		case 0x8D:    return "GUIDE";
		case 0x9C:    return "CH_UP";
		case 0x9D:    return "CH_DOWN";
		case 0xB0:    return "PLAY";
		case 0xB1:    return "PAUSE";
		case 0xB2:    return "RECORD";
		case 0xB3:    return "FAST_FORWARD";
		case 0xB4:    return "REWIND";
		case 0xB5:    return "SKIP_FORWARD";
		case 0xB6:    return "SKIP_BACKWARD";
		case 0xB7:    return "STOP";
		case 0xE2:    return "MUTE";
		case 0xE9:    return "VOL_UP";
		case 0xEA:    return "VOL_DOWN";
		case 0x204:   return "EXIT";
		case 0x224:   return "BACK";
		}
		break;

	case 0x41:			// GFRM100 type 0x41
		if (size != 2) goto unknown;
		key = data[1];
		switch (key) {
		case 0x00:    return "RELEASE41";
		case 0x1E:    return "DIGIT_1";
		case 0x1F:    return "DIGIT_2";
		case 0x20:    return "DIGIT_3";
		case 0x21:    return "DIGIT_4";
		case 0x22:    return "DIGIT_5";
		case 0x23:    return "DIGIT_6";
		case 0x24:    return "DIGIT_7";
		case 0x25:    return "DIGIT_8";
		case 0x26:    return "DIGIT_9";
		case 0x27:    return "DIGIT_0";
		case 0x2a:    return "DIGIT_DEL";
		}
		break;

	case 0xf7:			// GFRM100 type 0xf7
		if (size != 10) goto unknown;
		key = data[1];
		switch (key) {
		case 0x00:   return "SEARCH";
		case 0x02:   return "RELEASEF7";
		}
		break;
	}
unknown:
	sprintf(msg, "UNKNOWN=%04x-%04x-%04x", code, key, size);
	return msg;
}

static void dataToHexString(char* str, int strLen, u8* data, int dataLen)
{
	static char* hex = "0123456789abcdef";
	char* sp = str;
	char* esp = str + strLen;
	u8* dp = data;
	u8* edp = data + dataLen;

	if (strLen < 1) return;

	while (sp + 3 < esp && dp < edp) {
		*sp++ = hex[(*dp >> 4) & 0x0f];
		*sp++ = hex[(*dp >> 0) & 0x0f];
		dp++;
	}
	*sp = '\0';
}

static void logButton(struct hid_device *hdev, struct hid_report *report,
		u8 *data, int size)
{
	char dataStr[1024];
	const char* button = rawEventToButton(data, size);

	dataToHexString(dataStr, sizeof dataStr, data, size);

	// for backward compatibility with log parsers, use this format:
	// BTHID bthid_write: [00241cb74c8f]Sending report to HID: {1f4102} -> KEY_DIGIT_2
	printk(KERN_INFO "BTHID bthid_write: Sending report to HID: {%s} -> KEY_%s\n", dataStr, button);
}

static int gfrm_input_mapped(struct hid_device *hdev, struct hid_input *hi,
		struct hid_field *field, struct hid_usage *usage,
		unsigned long **bit, int *max)
{
	int hdev_type = (int)hid_get_drvdata(hdev);

	if (hdev_type == TIARC) {
		if (usage->code == KEY_LEFTMETA) {
			hid_map_usage(hi, usage, bit, max, usage->type, KEY_MENU);
		} else if (usage->code == KEY_BACKSPACE) {
			hid_map_usage(hi, usage, bit, max, usage->type, KEY_BACK);
		} else if (usage->code == KEY_MUTE) {
			hid_map_usage(hi, usage, bit, max, usage->type, KEY_PROGRAM);
		}
	}

	return 0;
}

static int gfrm_raw_event(struct hid_device *hdev, struct hid_report *report,
		u8 *data, int size)
{
	int hdev_type = (int)hid_get_drvdata(hdev);
	int ret = 0;

	logButton(hdev, report, data, size);

	if (hdev_type != GFRM100)
		return 0;

	if (size < 2 || data[0] != GFRM100_SEARCH_KEY_REPORT_ID)
		return 0;

	/*
	 * Convert GFRM100 Search key reports into Consumer.00f7 (Key.Search)
	 * reports. Ignore audio data.
	 */
	switch (data[1]) {
	case GFRM100_SEARCH_KEY_DOWN:
		ret = hid_input_report(hdev, HID_INPUT_REPORT, search_key_dn,
					sizeof(search_key_dn), 1);
		break;

	case GFRM100_SEARCH_KEY_AUDIO_DATA:
		break;

	case GFRM100_SEARCH_KEY_UP:
		ret = hid_input_report(hdev, HID_INPUT_REPORT, search_key_up,
					sizeof(search_key_up), 1);
		break;

	default:
		break;
	}

	return (ret < 0) ? ret : 1;
}

static int gfrm_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
	int ret;

	hid_set_drvdata(hdev, (void *)id->driver_data);

	ret = hid_parse(hdev);
	if (ret)
		goto done;

	if (id->driver_data == GFRM100) {
		/*
		 * GFRM100 HID Report Descriptor does not describe the Search
		 * key reports. Thus, we need to add it manually here, so that
		 * those reports reach gfrm_raw_event() from hid_input_report().
		 */
		if (!hid_register_report(hdev, HID_INPUT_REPORT,
					 GFRM100_SEARCH_KEY_REPORT_ID)) {
			ret = -ENOMEM;
			goto done;
		}
	}

	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
done:
	return ret;
}

static void gfrm_remove(struct hid_device *hdev)
{
	hid_hw_stop(hdev);
	hid_set_drvdata(hdev, NULL);
}

static const struct hid_device_id gfrm_devices[] = {
	{ HID_BLUETOOTH_DEVICE(0x58, 0x2000),
		.driver_data = GFRM100 },
	{ HID_BLUETOOTH_DEVICE(0x471, 0x2210),
		.driver_data = GFRM200 },
	{ HID_BLUETOOTH_DEVICE(0xD, 0x0),
		.driver_data = TIARC },
	{ }
};
MODULE_DEVICE_TABLE(hid, gfrm_devices);

static struct hid_driver gfrm_driver = {
	.name = "gfrm",
	.id_table = gfrm_devices,
	.probe = gfrm_probe,
	.remove = gfrm_remove,
	.input_mapped = gfrm_input_mapped,
	.raw_event = gfrm_raw_event,
};

static int __init gfrm_init(void)
{
	return hid_register_driver(&gfrm_driver);
}

static void __exit gfrm_exit(void)
{
	hid_unregister_driver(&gfrm_driver);
}

module_init(gfrm_init);
module_exit(gfrm_exit);
MODULE_LICENSE("GPL");