/*
   * SEGA Dreamcast keyboard driver
   * Based on drivers/usb/usbkbd.c
   * Copyright (c) YAEGASHI Takeshi, 2001
   * Porting to 2.6 Copyright (c) Adrian McMenamin, 2007 - 2009
   *
   * 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, see the file COPYING, or write
   * to the Free Software Foundation, Inc.,
   * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   */
  
  #include <linux/kernel.h>
  #include <linux/slab.h>
  #include <linux/input.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/timer.h>
  #include <linux/maple.h>
  
  /* Very simple mutex to ensure proper cleanup */
  static DEFINE_MUTEX(maple_keyb_mutex);
  
  #define NR_SCANCODES 256
  
  MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk");
  MODULE_DESCRIPTION("SEGA Dreamcast keyboard driver");
  MODULE_LICENSE("GPL");
  
  struct dc_kbd {
  	struct input_dev *dev;
  	unsigned short keycode[NR_SCANCODES];
  	unsigned char new[8];
  	unsigned char old[8];
  };
  
  static const unsigned short dc_kbd_keycode[NR_SCANCODES] = {
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_A, KEY_B,
  	KEY_C, KEY_D, KEY_E, KEY_F, KEY_G, KEY_H, KEY_I, KEY_J, KEY_K, KEY_L,
  	KEY_M, KEY_N, KEY_O, KEY_P, KEY_Q, KEY_R, KEY_S, KEY_T, KEY_U, KEY_V,
  	KEY_W, KEY_X, KEY_Y, KEY_Z, KEY_1, KEY_2, KEY_3, KEY_4, KEY_5, KEY_6,
  	KEY_7, KEY_8, KEY_9, KEY_0, KEY_ENTER, KEY_ESC, KEY_BACKSPACE,
  	KEY_TAB, KEY_SPACE, KEY_MINUS, KEY_EQUAL, KEY_LEFTBRACE,
  	KEY_RIGHTBRACE, KEY_BACKSLASH, KEY_BACKSLASH, KEY_SEMICOLON,
  	KEY_APOSTROPHE, KEY_GRAVE, KEY_COMMA, KEY_DOT, KEY_SLASH,
  	KEY_CAPSLOCK, KEY_F1, KEY_F2, KEY_F3, KEY_F4, KEY_F5, KEY_F6,
  	KEY_F7, KEY_F8, KEY_F9, KEY_F10, KEY_F11, KEY_F12, KEY_SYSRQ,
  	KEY_SCROLLLOCK, KEY_PAUSE, KEY_INSERT, KEY_HOME, KEY_PAGEUP,
  	KEY_DELETE, KEY_END, KEY_PAGEDOWN, KEY_RIGHT, KEY_LEFT, KEY_DOWN,
  	KEY_UP, KEY_NUMLOCK, KEY_KPSLASH, KEY_KPASTERISK, KEY_KPMINUS,
  	KEY_KPPLUS, KEY_KPENTER, KEY_KP1, KEY_KP2, KEY_KP3, KEY_KP4, KEY_KP5,
  	KEY_KP6, KEY_KP7, KEY_KP8, KEY_KP9, KEY_KP0, KEY_KPDOT, KEY_102ND,
  	KEY_COMPOSE, KEY_POWER, KEY_KPEQUAL, KEY_F13, KEY_F14, KEY_F15,
  	KEY_F16, KEY_F17, KEY_F18, KEY_F19, KEY_F20, KEY_F21, KEY_F22,
  	KEY_F23, KEY_F24, KEY_OPEN, KEY_HELP, KEY_PROPS, KEY_FRONT, KEY_STOP,
  	KEY_AGAIN, KEY_UNDO, KEY_CUT, KEY_COPY, KEY_PASTE, KEY_FIND, KEY_MUTE,
  	KEY_VOLUMEUP, KEY_VOLUMEDOWN, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_KPCOMMA, KEY_RESERVED, KEY_RO, KEY_KATAKANAHIRAGANA , KEY_YEN,
  	KEY_HENKAN, KEY_MUHENKAN, KEY_KPJPCOMMA, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_HANGEUL, KEY_HANJA, KEY_KATAKANA, KEY_HIRAGANA,
  	KEY_ZENKAKUHANKAKU, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
  	KEY_RESERVED, KEY_RESERVED, KEY_LEFTCTRL, KEY_LEFTSHIFT, KEY_LEFTALT,
  	KEY_LEFTMETA, KEY_RIGHTCTRL, KEY_RIGHTSHIFT, KEY_RIGHTALT,
  	KEY_RIGHTMETA, KEY_PLAYPAUSE, KEY_STOPCD, KEY_PREVIOUSSONG,
  	KEY_NEXTSONG, KEY_EJECTCD, KEY_VOLUMEUP, KEY_VOLUMEDOWN, KEY_MUTE,
  	KEY_WWW, KEY_BACK, KEY_FORWARD, KEY_STOP, KEY_FIND, KEY_SCROLLUP,
  	KEY_SCROLLDOWN, KEY_EDIT, KEY_SLEEP, KEY_SCREENLOCK, KEY_REFRESH,
  	KEY_CALC, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED
  };
  
  static void dc_scan_kbd(struct dc_kbd *kbd)
  {
  	struct input_dev *dev = kbd->dev;
  	void *ptr;
  	int code, keycode;
  	int i;
  
  	for (i = 0; i < 8; i++) {
  		code = i + 224;
  		keycode = kbd->keycode[code];
  		input_event(dev, EV_MSC, MSC_SCAN, code);
  		input_report_key(dev, keycode, (kbd->new[0] >> i) & 1);
  	}
  
  	for (i = 2; i < 8; i++) {
  		ptr = memchr(kbd->new + 2, kbd->old[i], 6);
  		code = kbd->old[i];
  		if (code > 3 && ptr == NULL) {
  			keycode = kbd->keycode[code];
  			if (keycode) {
  				input_event(dev, EV_MSC, MSC_SCAN, code);
  				input_report_key(dev, keycode, 0);
  			} else
  				dev_dbg(&dev->dev,
  					"Unknown key (scancode %#x) released.",
  					code);
  		}
  		ptr = memchr(kbd->old + 2, kbd->new[i], 6);
  		code = kbd->new[i];
  		if (code > 3 && ptr) {
  			keycode = kbd->keycode[code];
  			if (keycode) {
  				input_event(dev, EV_MSC, MSC_SCAN, code);
  				input_report_key(dev, keycode, 1);
  			} else
  				dev_dbg(&dev->dev,
  					"Unknown key (scancode %#x) pressed.",
  					code);
  		}
  	}
  	input_sync(dev);
  	memcpy(kbd->old, kbd->new, 8);
  }
  
  static void dc_kbd_callback(struct mapleq *mq)
  {
  	struct maple_device *mapledev = mq->dev;
  	struct dc_kbd *kbd = maple_get_drvdata(mapledev);
  	unsigned long *buf = (unsigned long *)(mq->recvbuf->buf);
  
  	/*
  	 * We should always get the lock because the only
  	 * time it may be locked is if the driver is in the cleanup phase.
  	 */
  	if (likely(mutex_trylock(&maple_keyb_mutex))) {
  
  		if (buf[1] == mapledev->function) {
  			memcpy(kbd->new, buf + 2, 8);
  			dc_scan_kbd(kbd);
  		}
  
  		mutex_unlock(&maple_keyb_mutex);
  	}
  }
  
  static int probe_maple_kbd(struct device *dev)
  {
  	struct maple_device *mdev;
  	struct maple_driver *mdrv;
  	int i, error;
  	struct dc_kbd *kbd;
  	struct input_dev *idev;
  
  	mdev = to_maple_dev(dev);
  	mdrv = to_maple_driver(dev->driver);
  
  	kbd = kzalloc(sizeof(struct dc_kbd), GFP_KERNEL);
  	if (!kbd) {
  		error = -ENOMEM;
  		goto fail;
  	}
  
  	idev = input_allocate_device();
  	if (!idev) {
  		error = -ENOMEM;
  		goto fail_idev_alloc;
  	}
  
  	kbd->dev = idev;
  	memcpy(kbd->keycode, dc_kbd_keycode, sizeof(kbd->keycode));
  
  	idev->name = mdev->product_name;
  	idev->evbit[0] = BIT(EV_KEY) | BIT(EV_REP);
  	idev->keycode = kbd->keycode;
  	idev->keycodesize = sizeof(unsigned short);
  	idev->keycodemax = ARRAY_SIZE(kbd->keycode);
  	idev->id.bustype = BUS_HOST;
  	idev->dev.parent = &mdev->dev;
  
  	for (i = 0; i < NR_SCANCODES; i++)
  		__set_bit(dc_kbd_keycode[i], idev->keybit);
  	__clear_bit(KEY_RESERVED, idev->keybit);
  
  	input_set_capability(idev, EV_MSC, MSC_SCAN);
  	input_set_drvdata(idev, kbd);
  
  	error = input_register_device(idev);
  	if (error)
  		goto fail_register;
  
  	/* Maple polling is locked to VBLANK - which may be just 50/s */
  	maple_getcond_callback(mdev, dc_kbd_callback, HZ/50,
  		MAPLE_FUNC_KEYBOARD);
  
  	mdev->driver = mdrv;
  
  	maple_set_drvdata(mdev, kbd);
  
  	return error;
  
  fail_register:
  	maple_set_drvdata(mdev, NULL);
  	input_free_device(idev);
  fail_idev_alloc:
  	kfree(kbd);
  fail:
  	return error;
  }
  
  static int remove_maple_kbd(struct device *dev)
  {
  	struct maple_device *mdev = to_maple_dev(dev);
  	struct dc_kbd *kbd = maple_get_drvdata(mdev);
  
  	mutex_lock(&maple_keyb_mutex);
  
  	input_unregister_device(kbd->dev);
  	kfree(kbd);
  
  	maple_set_drvdata(mdev, NULL);
  
  	mutex_unlock(&maple_keyb_mutex);
  	return 0;
  }
  
  static struct maple_driver dc_kbd_driver = {
  	.function = MAPLE_FUNC_KEYBOARD,
  	.drv = {
  		.name = "Dreamcast_keyboard",
  		.probe = probe_maple_kbd,
  		.remove = remove_maple_kbd,
  	},
  };
  
  static int __init dc_kbd_init(void)
  {
  	return maple_driver_register(&dc_kbd_driver);
  }
  
  static void __exit dc_kbd_exit(void)
  {
  	maple_driver_unregister(&dc_kbd_driver);
  }
  
  module_init(dc_kbd_init);
  module_exit(dc_kbd_exit);