/*
   *  Atheros Communication Bluetooth HCIATH3K UART protocol
   *
   *  HCIATH3K (HCI Atheros AR300x Protocol) is a Atheros Communication's
   *  power management protocol extension to H4 to support AR300x Bluetooth Chip.
   *
   *  Copyright (c) 2009-2010 Atheros Communications Inc.
   *
   *  Acknowledgements:
   *  This file is based on hci_h4.c, which was written
   *  by Maxim Krasnyansky and Marcel Holtmann.
   *
   *  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 <linux/module.h>
  #include <linux/kernel.h>
  
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/tty.h>
  #include <linux/errno.h>
  #include <linux/ioctl.h>
  #include <linux/skbuff.h>
  
  #include <net/bluetooth/bluetooth.h>
  #include <net/bluetooth/hci_core.h>
  
  #include "hci_uart.h"
  
  struct ath_struct {
  	struct hci_uart *hu;
  	unsigned int cur_sleep;
  
  	struct sk_buff_head txq;
  	struct work_struct ctxtsw;
  };
  
  static int ath_wakeup_ar3k(struct tty_struct *tty)
  {
  	struct ktermios ktermios;
  	int status = tty->driver->ops->tiocmget(tty);
  
  	if (status & TIOCM_CTS)
  		return status;
  
  	/* Disable Automatic RTSCTS */
  	ktermios = tty->termios;
  	ktermios.c_cflag &= ~CRTSCTS;
  	tty_set_termios(tty, &ktermios);
  
  	/* Clear RTS first */
  	status = tty->driver->ops->tiocmget(tty);
  	tty->driver->ops->tiocmset(tty, 0x00, TIOCM_RTS);
  	mdelay(20);
  
  	/* Set RTS, wake up board */
  	status = tty->driver->ops->tiocmget(tty);
  	tty->driver->ops->tiocmset(tty, TIOCM_RTS, 0x00);
  	mdelay(20);
  
  	status = tty->driver->ops->tiocmget(tty);
  
  	/* Disable Automatic RTSCTS */
  	ktermios.c_cflag |= CRTSCTS;
  	status = tty_set_termios(tty, &ktermios);
  
  	return status;
  }
  
  static void ath_hci_uart_work(struct work_struct *work)
  {
  	int status;
  	struct ath_struct *ath;
  	struct hci_uart *hu;
  	struct tty_struct *tty;
  
  	ath = container_of(work, struct ath_struct, ctxtsw);
  
  	hu = ath->hu;
  	tty = hu->tty;
  
  	/* verify and wake up controller */
  	if (ath->cur_sleep) {
  		status = ath_wakeup_ar3k(tty);
  		if (!(status & TIOCM_CTS))
  			return;
  	}
  
  	/* Ready to send Data */
  	clear_bit(HCI_UART_SENDING, &hu->tx_state);
  	hci_uart_tx_wakeup(hu);
  }
  
  /* Initialize protocol */
  static int ath_open(struct hci_uart *hu)
  {
  	struct ath_struct *ath;
  
  	BT_DBG("hu %p", hu);
  
  	ath = kzalloc(sizeof(*ath), GFP_KERNEL);
  	if (!ath)
  		return -ENOMEM;
  
  	skb_queue_head_init(&ath->txq);
  
  	hu->priv = ath;
  	ath->hu = hu;
  
  	INIT_WORK(&ath->ctxtsw, ath_hci_uart_work);
  
  	return 0;
  }
  
  /* Flush protocol data */
  static int ath_flush(struct hci_uart *hu)
  {
  	struct ath_struct *ath = hu->priv;
  
  	BT_DBG("hu %p", hu);
  
  	skb_queue_purge(&ath->txq);
  
  	return 0;
  }
  
  /* Close protocol */
  static int ath_close(struct hci_uart *hu)
  {
  	struct ath_struct *ath = hu->priv;
  
  	BT_DBG("hu %p", hu);
  
  	skb_queue_purge(&ath->txq);
  
  	cancel_work_sync(&ath->ctxtsw);
  
  	hu->priv = NULL;
  	kfree(ath);
  
  	return 0;
  }
  
  #define HCI_OP_ATH_SLEEP 0xFC04
  
  /* Enqueue frame for transmittion */
  static int ath_enqueue(struct hci_uart *hu, struct sk_buff *skb)
  {
  	struct ath_struct *ath = hu->priv;
  
  	if (bt_cb(skb)->pkt_type == HCI_SCODATA_PKT) {
  		kfree_skb(skb);
  		return 0;
  	}
  
  	/*
  	 * Update power management enable flag with parameters of
  	 * HCI sleep enable vendor specific HCI command.
  	 */
  	if (bt_cb(skb)->pkt_type == HCI_COMMAND_PKT) {
  		struct hci_command_hdr *hdr = (void *)skb->data;
  
  		if (__le16_to_cpu(hdr->opcode) == HCI_OP_ATH_SLEEP)
  			ath->cur_sleep = skb->data[HCI_COMMAND_HDR_SIZE];
  	}
  
  	BT_DBG("hu %p skb %p", hu, skb);
  
  	/* Prepend skb with frame type */
  	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
  
  	skb_queue_tail(&ath->txq, skb);
  	set_bit(HCI_UART_SENDING, &hu->tx_state);
  
  	schedule_work(&ath->ctxtsw);
  
  	return 0;
  }
  
  static struct sk_buff *ath_dequeue(struct hci_uart *hu)
  {
  	struct ath_struct *ath = hu->priv;
  
  	return skb_dequeue(&ath->txq);
  }
  
  /* Recv data */
  static int ath_recv(struct hci_uart *hu, void *data, int count)
  {
  	int ret;
  
  	ret = hci_recv_stream_fragment(hu->hdev, data, count);
  	if (ret < 0) {
  		BT_ERR("Frame Reassembly Failed");
  		return ret;
  	}
  
  	return count;
  }
  
  static struct hci_uart_proto athp = {
  	.id = HCI_UART_ATH3K,
  	.open = ath_open,
  	.close = ath_close,
  	.recv = ath_recv,
  	.enqueue = ath_enqueue,
  	.dequeue = ath_dequeue,
  	.flush = ath_flush,
  };
  
  int __init ath_init(void)
  {
  	int err = hci_uart_register_proto(&athp);
  
  	if (!err)
  		BT_INFO("HCIATH3K protocol initialized");
  	else
  		BT_ERR("HCIATH3K protocol registration failed");
  
  	return err;
  }
  
  int __exit ath_deinit(void)
  {
  	return hci_uart_unregister_proto(&athp);
  }