/*
   * ati_remote2 - ATI/Philips USB RF remote driver
   *
   * Copyright (C) 2005-2008 Ville Syrjala <syrjala@sci.fi>
   * Copyright (C) 2007-2008 Peter Stokes <linux@dadeos.co.uk>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2
   * as published by the Free Software Foundation.
   */
  
  #include <linux/usb/input.h>
  #include <linux/slab.h>
  #include <linux/module.h>
  
  #define DRIVER_DESC    "ATI/Philips USB RF remote driver"
  #define DRIVER_VERSION "0.3"
  
  MODULE_DESCRIPTION(DRIVER_DESC);
  MODULE_VERSION(DRIVER_VERSION);
  MODULE_AUTHOR("Ville Syrjala <syrjala@sci.fi>");
  MODULE_LICENSE("GPL");
  
  /*
   * ATI Remote Wonder II Channel Configuration
   *
   * The remote control can by assigned one of sixteen "channels" in order to facilitate
   * the use of multiple remote controls within range of each other.
   * A remote's "channel" may be altered by pressing and holding the "PC" button for
   * approximately 3 seconds, after which the button will slowly flash the count of the
   * currently configured "channel", using the numeric keypad enter a number between 1 and
   * 16 and then press the "PC" button again, the button will slowly flash the count of the
   * newly configured "channel".
   */
  
  enum {
  	ATI_REMOTE2_MAX_CHANNEL_MASK = 0xFFFF,
  	ATI_REMOTE2_MAX_MODE_MASK = 0x1F,
  };
  
  static int ati_remote2_set_mask(const char *val,
  				const struct kernel_param *kp,
  				unsigned int max)
  {
  	unsigned int mask;
  	int ret;
  
  	if (!val)
  		return -EINVAL;
  
  	ret = kstrtouint(val, 0, &mask);
  	if (ret)
  		return ret;
  
  	if (mask & ~max)
  		return -EINVAL;
  
  	*(unsigned int *)kp->arg = mask;
  
  	return 0;
  }
  
  static int ati_remote2_set_channel_mask(const char *val,
  					const struct kernel_param *kp)
  {
  	pr_debug("%s()
  ", __func__);
  
  	return ati_remote2_set_mask(val, kp, ATI_REMOTE2_MAX_CHANNEL_MASK);
  }
  
  static int ati_remote2_get_channel_mask(char *buffer,
  					const struct kernel_param *kp)
  {
  	pr_debug("%s()
  ", __func__);
  
  	return sprintf(buffer, "0x%04x", *(unsigned int *)kp->arg);
  }
  
  static int ati_remote2_set_mode_mask(const char *val,
  				     const struct kernel_param *kp)
  {
  	pr_debug("%s()
  ", __func__);
  
  	return ati_remote2_set_mask(val, kp, ATI_REMOTE2_MAX_MODE_MASK);
  }
  
  static int ati_remote2_get_mode_mask(char *buffer,
  				     const struct kernel_param *kp)
  {
  	pr_debug("%s()
  ", __func__);
  
  	return sprintf(buffer, "0x%02x", *(unsigned int *)kp->arg);
  }
  
  static unsigned int channel_mask = ATI_REMOTE2_MAX_CHANNEL_MASK;
  #define param_check_channel_mask(name, p) __param_check(name, p, unsigned int)
  static const struct kernel_param_ops param_ops_channel_mask = {
  	.set = ati_remote2_set_channel_mask,
  	.get = ati_remote2_get_channel_mask,
  };
  module_param(channel_mask, channel_mask, 0644);
  MODULE_PARM_DESC(channel_mask, "Bitmask of channels to accept <15:Channel16>...<1:Channel2><0:Channel1>");
  
  static unsigned int mode_mask = ATI_REMOTE2_MAX_MODE_MASK;
  #define param_check_mode_mask(name, p) __param_check(name, p, unsigned int)
  static const struct kernel_param_ops param_ops_mode_mask = {
  	.set = ati_remote2_set_mode_mask,
  	.get = ati_remote2_get_mode_mask,
  };
  module_param(mode_mask, mode_mask, 0644);
  MODULE_PARM_DESC(mode_mask, "Bitmask of modes to accept <4:PC><3:AUX4><2:AUX3><1:AUX2><0:AUX1>");
  
  static struct usb_device_id ati_remote2_id_table[] = {
  	{ USB_DEVICE(0x0471, 0x0602) },	/* ATI Remote Wonder II */
  	{ }
  };
  MODULE_DEVICE_TABLE(usb, ati_remote2_id_table);
  
  static DEFINE_MUTEX(ati_remote2_mutex);
  
  enum {
  	ATI_REMOTE2_OPENED = 0x1,
  	ATI_REMOTE2_SUSPENDED = 0x2,
  };
  
  enum {
  	ATI_REMOTE2_AUX1,
  	ATI_REMOTE2_AUX2,
  	ATI_REMOTE2_AUX3,
  	ATI_REMOTE2_AUX4,
  	ATI_REMOTE2_PC,
  	ATI_REMOTE2_MODES,
  };
  
  static const struct {
  	u8  hw_code;
  	u16 keycode;
  } ati_remote2_key_table[] = {
  	{ 0x00, KEY_0 },
  	{ 0x01, KEY_1 },
  	{ 0x02, KEY_2 },
  	{ 0x03, KEY_3 },
  	{ 0x04, KEY_4 },
  	{ 0x05, KEY_5 },
  	{ 0x06, KEY_6 },
  	{ 0x07, KEY_7 },
  	{ 0x08, KEY_8 },
  	{ 0x09, KEY_9 },
  	{ 0x0c, KEY_POWER },
  	{ 0x0d, KEY_MUTE },
  	{ 0x10, KEY_VOLUMEUP },
  	{ 0x11, KEY_VOLUMEDOWN },
  	{ 0x20, KEY_CHANNELUP },
  	{ 0x21, KEY_CHANNELDOWN },
  	{ 0x28, KEY_FORWARD },
  	{ 0x29, KEY_REWIND },
  	{ 0x2c, KEY_PLAY },
  	{ 0x30, KEY_PAUSE },
  	{ 0x31, KEY_STOP },
  	{ 0x37, KEY_RECORD },
  	{ 0x38, KEY_DVD },
  	{ 0x39, KEY_TV },
  	{ 0x3f, KEY_PROG1 }, /* AUX1-AUX4 and PC */
  	{ 0x54, KEY_MENU },
  	{ 0x58, KEY_UP },
  	{ 0x59, KEY_DOWN },
  	{ 0x5a, KEY_LEFT },
  	{ 0x5b, KEY_RIGHT },
  	{ 0x5c, KEY_OK },
  	{ 0x78, KEY_A },
  	{ 0x79, KEY_B },
  	{ 0x7a, KEY_C },
  	{ 0x7b, KEY_D },
  	{ 0x7c, KEY_E },
  	{ 0x7d, KEY_F },
  	{ 0x82, KEY_ENTER },
  	{ 0x8e, KEY_VENDOR },
  	{ 0x96, KEY_COFFEE },
  	{ 0xa9, BTN_LEFT },
  	{ 0xaa, BTN_RIGHT },
  	{ 0xbe, KEY_QUESTION },
  	{ 0xd0, KEY_EDIT },
  	{ 0xd5, KEY_FRONT },
  	{ 0xf9, KEY_INFO },
  };
  
  struct ati_remote2 {
  	struct input_dev *idev;
  	struct usb_device *udev;
  
  	struct usb_interface *intf[2];
  	struct usb_endpoint_descriptor *ep[2];
  	struct urb *urb[2];
  	void *buf[2];
  	dma_addr_t buf_dma[2];
  
  	unsigned long jiffies;
  	int mode;
  
  	char name[64];
  	char phys[64];
  
  	/* Each mode (AUX1-AUX4 and PC) can have an independent keymap. */
  	u16 keycode[ATI_REMOTE2_MODES][ARRAY_SIZE(ati_remote2_key_table)];
  
  	unsigned int flags;
  
  	unsigned int channel_mask;
  	unsigned int mode_mask;
  };
  
  static int ati_remote2_probe(struct usb_interface *interface, const struct usb_device_id *id);
  static void ati_remote2_disconnect(struct usb_interface *interface);
  static int ati_remote2_suspend(struct usb_interface *interface, pm_message_t message);
  static int ati_remote2_resume(struct usb_interface *interface);
  static int ati_remote2_reset_resume(struct usb_interface *interface);
  static int ati_remote2_pre_reset(struct usb_interface *interface);
  static int ati_remote2_post_reset(struct usb_interface *interface);
  
  static struct usb_driver ati_remote2_driver = {
  	.name       = "ati_remote2",
  	.probe      = ati_remote2_probe,
  	.disconnect = ati_remote2_disconnect,
  	.id_table   = ati_remote2_id_table,
  	.suspend    = ati_remote2_suspend,
  	.resume     = ati_remote2_resume,
  	.reset_resume = ati_remote2_reset_resume,
  	.pre_reset  = ati_remote2_pre_reset,
  	.post_reset = ati_remote2_post_reset,
  	.supports_autosuspend = 1,
  };
  
  static int ati_remote2_submit_urbs(struct ati_remote2 *ar2)
  {
  	int r;
  
  	r = usb_submit_urb(ar2->urb[0], GFP_KERNEL);
  	if (r) {
  		dev_err(&ar2->intf[0]->dev,
  			"%s(): usb_submit_urb() = %d
  ", __func__, r);
  		return r;
  	}
  	r = usb_submit_urb(ar2->urb[1], GFP_KERNEL);
  	if (r) {
  		usb_kill_urb(ar2->urb[0]);
  		dev_err(&ar2->intf[1]->dev,
  			"%s(): usb_submit_urb() = %d
  ", __func__, r);
  		return r;
  	}
  
  	return 0;
  }
  
  static void ati_remote2_kill_urbs(struct ati_remote2 *ar2)
  {
  	usb_kill_urb(ar2->urb[1]);
  	usb_kill_urb(ar2->urb[0]);
  }
  
  static int ati_remote2_open(struct input_dev *idev)
  {
  	struct ati_remote2 *ar2 = input_get_drvdata(idev);
  	int r;
  
  	dev_dbg(&ar2->intf[0]->dev, "%s()
  ", __func__);
  
  	r = usb_autopm_get_interface(ar2->intf[0]);
  	if (r) {
  		dev_err(&ar2->intf[0]->dev,
  			"%s(): usb_autopm_get_interface() = %d
  ", __func__, r);
  		goto fail1;
  	}
  
  	mutex_lock(&ati_remote2_mutex);
  
  	if (!(ar2->flags & ATI_REMOTE2_SUSPENDED)) {
  		r = ati_remote2_submit_urbs(ar2);
  		if (r)
  			goto fail2;
  	}
  
  	ar2->flags |= ATI_REMOTE2_OPENED;
  
  	mutex_unlock(&ati_remote2_mutex);
  
  	usb_autopm_put_interface(ar2->intf[0]);
  
  	return 0;
  
   fail2:
  	mutex_unlock(&ati_remote2_mutex);
  	usb_autopm_put_interface(ar2->intf[0]);
   fail1:
  	return r;
  }
  
  static void ati_remote2_close(struct input_dev *idev)
  {
  	struct ati_remote2 *ar2 = input_get_drvdata(idev);
  
  	dev_dbg(&ar2->intf[0]->dev, "%s()
  ", __func__);
  
  	mutex_lock(&ati_remote2_mutex);
  
  	if (!(ar2->flags & ATI_REMOTE2_SUSPENDED))
  		ati_remote2_kill_urbs(ar2);
  
  	ar2->flags &= ~ATI_REMOTE2_OPENED;
  
  	mutex_unlock(&ati_remote2_mutex);
  }
  
  static void ati_remote2_input_mouse(struct ati_remote2 *ar2)
  {
  	struct input_dev *idev = ar2->idev;
  	u8 *data = ar2->buf[0];
  	int channel, mode;
  
  	channel = data[0] >> 4;
  
  	if (!((1 << channel) & ar2->channel_mask))
  		return;
  
  	mode = data[0] & 0x0F;
  
  	if (mode > ATI_REMOTE2_PC) {
  		dev_err(&ar2->intf[0]->dev,
  			"Unknown mode byte (%02x %02x %02x %02x)
  ",
  			data[3], data[2], data[1], data[0]);
  		return;
  	}
  
  	if (!((1 << mode) & ar2->mode_mask))
  		return;
  
  	input_event(idev, EV_REL, REL_X, (s8) data[1]);
  	input_event(idev, EV_REL, REL_Y, (s8) data[2]);
  	input_sync(idev);
  }
  
  static int ati_remote2_lookup(unsigned int hw_code)
  {
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(ati_remote2_key_table); i++)
  		if (ati_remote2_key_table[i].hw_code == hw_code)
  			return i;
  
  	return -1;
  }
  
  static void ati_remote2_input_key(struct ati_remote2 *ar2)
  {
  	struct input_dev *idev = ar2->idev;
  	u8 *data = ar2->buf[1];
  	int channel, mode, hw_code, index;
  
  	channel = data[0] >> 4;
  
  	if (!((1 << channel) & ar2->channel_mask))
  		return;
  
  	mode = data[0] & 0x0F;
  
  	if (mode > ATI_REMOTE2_PC) {
  		dev_err(&ar2->intf[1]->dev,
  			"Unknown mode byte (%02x %02x %02x %02x)
  ",
  			data[3], data[2], data[1], data[0]);
  		return;
  	}
  
  	hw_code = data[2];
  	if (hw_code == 0x3f) {
  		/*
  		 * For some incomprehensible reason the mouse pad generates
  		 * events which look identical to the events from the last
  		 * pressed mode key. Naturally we don't want to generate key
  		 * events for the mouse pad so we filter out any subsequent
  		 * events from the same mode key.
  		 */
  		if (ar2->mode == mode)
  			return;
  
  		if (data[1] == 0)
  			ar2->mode = mode;
  	}
  
  	if (!((1 << mode) & ar2->mode_mask))
  		return;
  
  	index = ati_remote2_lookup(hw_code);
  	if (index < 0) {
  		dev_err(&ar2->intf[1]->dev,
  			"Unknown code byte (%02x %02x %02x %02x)
  ",
  			data[3], data[2], data[1], data[0]);
  		return;
  	}
  
  	switch (data[1]) {
  	case 0:	/* release */
  		break;
  	case 1:	/* press */
  		ar2->jiffies = jiffies + msecs_to_jiffies(idev->rep[REP_DELAY]);
  		break;
  	case 2:	/* repeat */
  
  		/* No repeat for mouse buttons. */
  		if (ar2->keycode[mode][index] == BTN_LEFT ||
  		    ar2->keycode[mode][index] == BTN_RIGHT)
  			return;
  
  		if (!time_after_eq(jiffies, ar2->jiffies))
  			return;
  
  		ar2->jiffies = jiffies + msecs_to_jiffies(idev->rep[REP_PERIOD]);
  		break;
  	default:
  		dev_err(&ar2->intf[1]->dev,
  			"Unknown state byte (%02x %02x %02x %02x)
  ",
  			data[3], data[2], data[1], data[0]);
  		return;
  	}
  
  	input_event(idev, EV_KEY, ar2->keycode[mode][index], data[1]);
  	input_sync(idev);
  }
  
  static void ati_remote2_complete_mouse(struct urb *urb)
  {
  	struct ati_remote2 *ar2 = urb->context;
  	int r;
  
  	switch (urb->status) {
  	case 0:
  		usb_mark_last_busy(ar2->udev);
  		ati_remote2_input_mouse(ar2);
  		break;
  	case -ENOENT:
  	case -EILSEQ:
  	case -ECONNRESET:
  	case -ESHUTDOWN:
  		dev_dbg(&ar2->intf[0]->dev,
  			"%s(): urb status = %d
  ", __func__, urb->status);
  		return;
  	default:
  		usb_mark_last_busy(ar2->udev);
  		dev_err(&ar2->intf[0]->dev,
  			"%s(): urb status = %d
  ", __func__, urb->status);
  	}
  
  	r = usb_submit_urb(urb, GFP_ATOMIC);
  	if (r)
  		dev_err(&ar2->intf[0]->dev,
  			"%s(): usb_submit_urb() = %d
  ", __func__, r);
  }
  
  static void ati_remote2_complete_key(struct urb *urb)
  {
  	struct ati_remote2 *ar2 = urb->context;
  	int r;
  
  	switch (urb->status) {
  	case 0:
  		usb_mark_last_busy(ar2->udev);
  		ati_remote2_input_key(ar2);
  		break;
  	case -ENOENT:
  	case -EILSEQ:
  	case -ECONNRESET:
  	case -ESHUTDOWN:
  		dev_dbg(&ar2->intf[1]->dev,
  			"%s(): urb status = %d
  ", __func__, urb->status);
  		return;
  	default:
  		usb_mark_last_busy(ar2->udev);
  		dev_err(&ar2->intf[1]->dev,
  			"%s(): urb status = %d
  ", __func__, urb->status);
  	}
  
  	r = usb_submit_urb(urb, GFP_ATOMIC);
  	if (r)
  		dev_err(&ar2->intf[1]->dev,
  			"%s(): usb_submit_urb() = %d
  ", __func__, r);
  }
  
  static int ati_remote2_getkeycode(struct input_dev *idev,
  				  struct input_keymap_entry *ke)
  {
  	struct ati_remote2 *ar2 = input_get_drvdata(idev);
  	unsigned int mode;
  	int offset;
  	unsigned int index;
  	unsigned int scancode;
  
  	if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
  		index = ke->index;
  		if (index >= ATI_REMOTE2_MODES *
  				ARRAY_SIZE(ati_remote2_key_table))
  			return -EINVAL;
  
  		mode = ke->index / ARRAY_SIZE(ati_remote2_key_table);
  		offset = ke->index % ARRAY_SIZE(ati_remote2_key_table);
  		scancode = (mode << 8) + ati_remote2_key_table[offset].hw_code;
  	} else {
  		if (input_scancode_to_scalar(ke, &scancode))
  			return -EINVAL;
  
  		mode = scancode >> 8;
  		if (mode > ATI_REMOTE2_PC)
  			return -EINVAL;
  
  		offset = ati_remote2_lookup(scancode & 0xff);
  		if (offset < 0)
  			return -EINVAL;
  
  		index = mode * ARRAY_SIZE(ati_remote2_key_table) + offset;
  	}
  
  	ke->keycode = ar2->keycode[mode][offset];
  	ke->len = sizeof(scancode);
  	memcpy(&ke->scancode, &scancode, sizeof(scancode));
  	ke->index = index;
  
  	return 0;
  }
  
  static int ati_remote2_setkeycode(struct input_dev *idev,
  				  const struct input_keymap_entry *ke,
  				  unsigned int *old_keycode)
  {
  	struct ati_remote2 *ar2 = input_get_drvdata(idev);
  	unsigned int mode;
  	int offset;
  	unsigned int index;
  	unsigned int scancode;
  
  	if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
  		if (ke->index >= ATI_REMOTE2_MODES *
  				ARRAY_SIZE(ati_remote2_key_table))
  			return -EINVAL;
  
  		mode = ke->index / ARRAY_SIZE(ati_remote2_key_table);
  		offset = ke->index % ARRAY_SIZE(ati_remote2_key_table);
  	} else {
  		if (input_scancode_to_scalar(ke, &scancode))
  			return -EINVAL;
  
  		mode = scancode >> 8;
  		if (mode > ATI_REMOTE2_PC)
  			return -EINVAL;
  
  		offset = ati_remote2_lookup(scancode & 0xff);
  		if (offset < 0)
  			return -EINVAL;
  	}
  
  	*old_keycode = ar2->keycode[mode][offset];
  	ar2->keycode[mode][offset] = ke->keycode;
  	__set_bit(ke->keycode, idev->keybit);
  
  	for (mode = 0; mode < ATI_REMOTE2_MODES; mode++) {
  		for (index = 0; index < ARRAY_SIZE(ati_remote2_key_table); index++) {
  			if (ar2->keycode[mode][index] == *old_keycode)
  				return 0;
  		}
  	}
  
  	__clear_bit(*old_keycode, idev->keybit);
  
  	return 0;
  }
  
  static int ati_remote2_input_init(struct ati_remote2 *ar2)
  {
  	struct input_dev *idev;
  	int index, mode, retval;
  
  	idev = input_allocate_device();
  	if (!idev)
  		return -ENOMEM;
  
  	ar2->idev = idev;
  	input_set_drvdata(idev, ar2);
  
  	idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP) | BIT_MASK(EV_REL);
  	idev->keybit[BIT_WORD(BTN_MOUSE)] = BIT_MASK(BTN_LEFT) |
  		BIT_MASK(BTN_RIGHT);
  	idev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y);
  
  	for (mode = 0; mode < ATI_REMOTE2_MODES; mode++) {
  		for (index = 0; index < ARRAY_SIZE(ati_remote2_key_table); index++) {
  			ar2->keycode[mode][index] = ati_remote2_key_table[index].keycode;
  			__set_bit(ar2->keycode[mode][index], idev->keybit);
  		}
  	}
  
  	/* AUX1-AUX4 and PC generate the same scancode. */
  	index = ati_remote2_lookup(0x3f);
  	ar2->keycode[ATI_REMOTE2_AUX1][index] = KEY_PROG1;
  	ar2->keycode[ATI_REMOTE2_AUX2][index] = KEY_PROG2;
  	ar2->keycode[ATI_REMOTE2_AUX3][index] = KEY_PROG3;
  	ar2->keycode[ATI_REMOTE2_AUX4][index] = KEY_PROG4;
  	ar2->keycode[ATI_REMOTE2_PC][index] = KEY_PC;
  	__set_bit(KEY_PROG1, idev->keybit);
  	__set_bit(KEY_PROG2, idev->keybit);
  	__set_bit(KEY_PROG3, idev->keybit);
  	__set_bit(KEY_PROG4, idev->keybit);
  	__set_bit(KEY_PC, idev->keybit);
  
  	idev->rep[REP_DELAY]  = 250;
  	idev->rep[REP_PERIOD] = 33;
  
  	idev->open = ati_remote2_open;
  	idev->close = ati_remote2_close;
  
  	idev->getkeycode = ati_remote2_getkeycode;
  	idev->setkeycode = ati_remote2_setkeycode;
  
  	idev->name = ar2->name;
  	idev->phys = ar2->phys;
  
  	usb_to_input_id(ar2->udev, &idev->id);
  	idev->dev.parent = &ar2->udev->dev;
  
  	retval = input_register_device(idev);
  	if (retval)
  		input_free_device(idev);
  
  	return retval;
  }
  
  static int ati_remote2_urb_init(struct ati_remote2 *ar2)
  {
  	struct usb_device *udev = ar2->udev;
  	int i, pipe, maxp;
  
  	for (i = 0; i < 2; i++) {
  		ar2->buf[i] = usb_alloc_coherent(udev, 4, GFP_KERNEL, &ar2->buf_dma[i]);
  		if (!ar2->buf[i])
  			return -ENOMEM;
  
  		ar2->urb[i] = usb_alloc_urb(0, GFP_KERNEL);
  		if (!ar2->urb[i])
  			return -ENOMEM;
  
  		pipe = usb_rcvintpipe(udev, ar2->ep[i]->bEndpointAddress);
  		maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
  		maxp = maxp > 4 ? 4 : maxp;
  
  		usb_fill_int_urb(ar2->urb[i], udev, pipe, ar2->buf[i], maxp,
  				 i ? ati_remote2_complete_key : ati_remote2_complete_mouse,
  				 ar2, ar2->ep[i]->bInterval);
  		ar2->urb[i]->transfer_dma = ar2->buf_dma[i];
  		ar2->urb[i]->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
  	}
  
  	return 0;
  }
  
  static void ati_remote2_urb_cleanup(struct ati_remote2 *ar2)
  {
  	int i;
  
  	for (i = 0; i < 2; i++) {
  		usb_free_urb(ar2->urb[i]);
  		usb_free_coherent(ar2->udev, 4, ar2->buf[i], ar2->buf_dma[i]);
  	}
  }
  
  static int ati_remote2_setup(struct ati_remote2 *ar2, unsigned int ch_mask)
  {
  	int r, i, channel;
  
  	/*
  	 * Configure receiver to only accept input from remote "channel"
  	 *  channel == 0  -> Accept input from any remote channel
  	 *  channel == 1  -> Only accept input from remote channel 1
  	 *  channel == 2  -> Only accept input from remote channel 2
  	 *  ...
  	 *  channel == 16 -> Only accept input from remote channel 16
  	 */
  
  	channel = 0;
  	for (i = 0; i < 16; i++) {
  		if ((1 << i) & ch_mask) {
  			if (!(~(1 << i) & ch_mask))
  				channel = i + 1;
  			break;
  		}
  	}
  
  	r = usb_control_msg(ar2->udev, usb_sndctrlpipe(ar2->udev, 0),
  			    0x20,
  			    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
  			    channel, 0x0, NULL, 0, USB_CTRL_SET_TIMEOUT);
  	if (r) {
  		dev_err(&ar2->udev->dev, "%s - failed to set channel due to error: %d
  ",
  			__func__, r);
  		return r;
  	}
  
  	return 0;
  }
  
  static ssize_t ati_remote2_show_channel_mask(struct device *dev,
  					     struct device_attribute *attr,
  					     char *buf)
  {
  	struct usb_device *udev = to_usb_device(dev);
  	struct usb_interface *intf = usb_ifnum_to_if(udev, 0);
  	struct ati_remote2 *ar2 = usb_get_intfdata(intf);
  
  	return sprintf(buf, "0x%04x
  ", ar2->channel_mask);
  }
  
  static ssize_t ati_remote2_store_channel_mask(struct device *dev,
  					      struct device_attribute *attr,
  					      const char *buf, size_t count)
  {
  	struct usb_device *udev = to_usb_device(dev);
  	struct usb_interface *intf = usb_ifnum_to_if(udev, 0);
  	struct ati_remote2 *ar2 = usb_get_intfdata(intf);
  	unsigned int mask;
  	int r;
  
  	r = kstrtouint(buf, 0, &mask);
  	if (r)
  		return r;
  
  	if (mask & ~ATI_REMOTE2_MAX_CHANNEL_MASK)
  		return -EINVAL;
  
  	r = usb_autopm_get_interface(ar2->intf[0]);
  	if (r) {
  		dev_err(&ar2->intf[0]->dev,
  			"%s(): usb_autopm_get_interface() = %d
  ", __func__, r);
  		return r;
  	}
  
  	mutex_lock(&ati_remote2_mutex);
  
  	if (mask != ar2->channel_mask) {
  		r = ati_remote2_setup(ar2, mask);
  		if (!r)
  			ar2->channel_mask = mask;
  	}
  
  	mutex_unlock(&ati_remote2_mutex);
  
  	usb_autopm_put_interface(ar2->intf[0]);
  
  	return r ? r : count;
  }
  
  static ssize_t ati_remote2_show_mode_mask(struct device *dev,
  					  struct device_attribute *attr,
  					  char *buf)
  {
  	struct usb_device *udev = to_usb_device(dev);
  	struct usb_interface *intf = usb_ifnum_to_if(udev, 0);
  	struct ati_remote2 *ar2 = usb_get_intfdata(intf);
  
  	return sprintf(buf, "0x%02x
  ", ar2->mode_mask);
  }
  
  static ssize_t ati_remote2_store_mode_mask(struct device *dev,
  					   struct device_attribute *attr,
  					   const char *buf, size_t count)
  {
  	struct usb_device *udev = to_usb_device(dev);
  	struct usb_interface *intf = usb_ifnum_to_if(udev, 0);
  	struct ati_remote2 *ar2 = usb_get_intfdata(intf);
  	unsigned int mask;
  	int err;
  
  	err = kstrtouint(buf, 0, &mask);
  	if (err)
  		return err;
  
  	if (mask & ~ATI_REMOTE2_MAX_MODE_MASK)
  		return -EINVAL;
  
  	ar2->mode_mask = mask;
  
  	return count;
  }
  
  static DEVICE_ATTR(channel_mask, 0644, ati_remote2_show_channel_mask,
  		   ati_remote2_store_channel_mask);
  
  static DEVICE_ATTR(mode_mask, 0644, ati_remote2_show_mode_mask,
  		   ati_remote2_store_mode_mask);
  
  static struct attribute *ati_remote2_attrs[] = {
  	&dev_attr_channel_mask.attr,
  	&dev_attr_mode_mask.attr,
  	NULL,
  };
  
  static struct attribute_group ati_remote2_attr_group = {
  	.attrs = ati_remote2_attrs,
  };
  
  static int ati_remote2_probe(struct usb_interface *interface, const struct usb_device_id *id)
  {
  	struct usb_device *udev = interface_to_usbdev(interface);
  	struct usb_host_interface *alt = interface->cur_altsetting;
  	struct ati_remote2 *ar2;
  	int r;
  
  	if (alt->desc.bInterfaceNumber)
  		return -ENODEV;
  
  	ar2 = kzalloc(sizeof (struct ati_remote2), GFP_KERNEL);
  	if (!ar2)
  		return -ENOMEM;
  
  	ar2->udev = udev;
  
  	/* Sanity check, first interface must have an endpoint */
  	if (alt->desc.bNumEndpoints < 1 || !alt->endpoint) {
  		dev_err(&interface->dev,
  			"%s(): interface 0 must have an endpoint
  ", __func__);
  		r = -ENODEV;
  		goto fail1;
  	}
  	ar2->intf[0] = interface;
  	ar2->ep[0] = &alt->endpoint[0].desc;
  
  	/* Sanity check, the device must have two interfaces */
  	ar2->intf[1] = usb_ifnum_to_if(udev, 1);
  	if ((udev->actconfig->desc.bNumInterfaces < 2) || !ar2->intf[1]) {
  		dev_err(&interface->dev, "%s(): need 2 interfaces, found %d
  ",
  			__func__, udev->actconfig->desc.bNumInterfaces);
  		r = -ENODEV;
  		goto fail1;
  	}
  
  	r = usb_driver_claim_interface(&ati_remote2_driver, ar2->intf[1], ar2);
  	if (r)
  		goto fail1;
  
  	/* Sanity check, second interface must have an endpoint */
  	alt = ar2->intf[1]->cur_altsetting;
  	if (alt->desc.bNumEndpoints < 1 || !alt->endpoint) {
  		dev_err(&interface->dev,
  			"%s(): interface 1 must have an endpoint
  ", __func__);
  		r = -ENODEV;
  		goto fail2;
  	}
  	ar2->ep[1] = &alt->endpoint[0].desc;
  
  	r = ati_remote2_urb_init(ar2);
  	if (r)
  		goto fail3;
  
  	ar2->channel_mask = channel_mask;
  	ar2->mode_mask = mode_mask;
  
  	r = ati_remote2_setup(ar2, ar2->channel_mask);
  	if (r)
  		goto fail3;
  
  	usb_make_path(udev, ar2->phys, sizeof(ar2->phys));
  	strlcat(ar2->phys, "/input0", sizeof(ar2->phys));
  
  	strlcat(ar2->name, "ATI Remote Wonder II", sizeof(ar2->name));
  
  	r = sysfs_create_group(&udev->dev.kobj, &ati_remote2_attr_group);
  	if (r)
  		goto fail3;
  
  	r = ati_remote2_input_init(ar2);
  	if (r)
  		goto fail4;
  
  	usb_set_intfdata(interface, ar2);
  
  	interface->needs_remote_wakeup = 1;
  
  	return 0;
  
   fail4:
  	sysfs_remove_group(&udev->dev.kobj, &ati_remote2_attr_group);
   fail3:
  	ati_remote2_urb_cleanup(ar2);
   fail2:
  	usb_driver_release_interface(&ati_remote2_driver, ar2->intf[1]);
   fail1:
  	kfree(ar2);
  
  	return r;
  }
  
  static void ati_remote2_disconnect(struct usb_interface *interface)
  {
  	struct ati_remote2 *ar2;
  	struct usb_host_interface *alt = interface->cur_altsetting;
  
  	if (alt->desc.bInterfaceNumber)
  		return;
  
  	ar2 = usb_get_intfdata(interface);
  	usb_set_intfdata(interface, NULL);
  
  	input_unregister_device(ar2->idev);
  
  	sysfs_remove_group(&ar2->udev->dev.kobj, &ati_remote2_attr_group);
  
  	ati_remote2_urb_cleanup(ar2);
  
  	usb_driver_release_interface(&ati_remote2_driver, ar2->intf[1]);
  
  	kfree(ar2);
  }
  
  static int ati_remote2_suspend(struct usb_interface *interface,
  			       pm_message_t message)
  {
  	struct ati_remote2 *ar2;
  	struct usb_host_interface *alt = interface->cur_altsetting;
  
  	if (alt->desc.bInterfaceNumber)
  		return 0;
  
  	ar2 = usb_get_intfdata(interface);
  
  	dev_dbg(&ar2->intf[0]->dev, "%s()
  ", __func__);
  
  	mutex_lock(&ati_remote2_mutex);
  
  	if (ar2->flags & ATI_REMOTE2_OPENED)
  		ati_remote2_kill_urbs(ar2);
  
  	ar2->flags |= ATI_REMOTE2_SUSPENDED;
  
  	mutex_unlock(&ati_remote2_mutex);
  
  	return 0;
  }
  
  static int ati_remote2_resume(struct usb_interface *interface)
  {
  	struct ati_remote2 *ar2;
  	struct usb_host_interface *alt = interface->cur_altsetting;
  	int r = 0;
  
  	if (alt->desc.bInterfaceNumber)
  		return 0;
  
  	ar2 = usb_get_intfdata(interface);
  
  	dev_dbg(&ar2->intf[0]->dev, "%s()
  ", __func__);
  
  	mutex_lock(&ati_remote2_mutex);
  
  	if (ar2->flags & ATI_REMOTE2_OPENED)
  		r = ati_remote2_submit_urbs(ar2);
  
  	if (!r)
  		ar2->flags &= ~ATI_REMOTE2_SUSPENDED;
  
  	mutex_unlock(&ati_remote2_mutex);
  
  	return r;
  }
  
  static int ati_remote2_reset_resume(struct usb_interface *interface)
  {
  	struct ati_remote2 *ar2;
  	struct usb_host_interface *alt = interface->cur_altsetting;
  	int r = 0;
  
  	if (alt->desc.bInterfaceNumber)
  		return 0;
  
  	ar2 = usb_get_intfdata(interface);
  
  	dev_dbg(&ar2->intf[0]->dev, "%s()
  ", __func__);
  
  	mutex_lock(&ati_remote2_mutex);
  
  	r = ati_remote2_setup(ar2, ar2->channel_mask);
  	if (r)
  		goto out;
  
  	if (ar2->flags & ATI_REMOTE2_OPENED)
  		r = ati_remote2_submit_urbs(ar2);
  
  	if (!r)
  		ar2->flags &= ~ATI_REMOTE2_SUSPENDED;
  
   out:
  	mutex_unlock(&ati_remote2_mutex);
  
  	return r;
  }
  
  static int ati_remote2_pre_reset(struct usb_interface *interface)
  {
  	struct ati_remote2 *ar2;
  	struct usb_host_interface *alt = interface->cur_altsetting;
  
  	if (alt->desc.bInterfaceNumber)
  		return 0;
  
  	ar2 = usb_get_intfdata(interface);
  
  	dev_dbg(&ar2->intf[0]->dev, "%s()
  ", __func__);
  
  	mutex_lock(&ati_remote2_mutex);
  
  	if (ar2->flags == ATI_REMOTE2_OPENED)
  		ati_remote2_kill_urbs(ar2);
  
  	return 0;
  }
  
  static int ati_remote2_post_reset(struct usb_interface *interface)
  {
  	struct ati_remote2 *ar2;
  	struct usb_host_interface *alt = interface->cur_altsetting;
  	int r = 0;
  
  	if (alt->desc.bInterfaceNumber)
  		return 0;
  
  	ar2 = usb_get_intfdata(interface);
  
  	dev_dbg(&ar2->intf[0]->dev, "%s()
  ", __func__);
  
  	if (ar2->flags == ATI_REMOTE2_OPENED)
  		r = ati_remote2_submit_urbs(ar2);
  
  	mutex_unlock(&ati_remote2_mutex);
  
  	return r;
  }
  
  module_usb_driver(ati_remote2_driver);