/*
   *
   *  Generic Bluetooth SDIO driver
   *
   *  Copyright (C) 2007  Cambridge Silicon Radio Ltd.
   *  Copyright (C) 2007  Marcel Holtmann <marcel@holtmann.org>
   *
   *
   *  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/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/types.h>
  #include <linux/sched.h>
  #include <linux/errno.h>
  #include <linux/skbuff.h>
  
  #include <linux/mmc/sdio_ids.h>
  #include <linux/mmc/sdio_func.h>
  
  #include <net/bluetooth/bluetooth.h>
  #include <net/bluetooth/hci_core.h>

  #define VERSION "0.1"
  
  static const struct sdio_device_id btsdio_table[] = {
  	/* Generic Bluetooth Type-A SDIO device */
  	{ SDIO_DEVICE_CLASS(SDIO_CLASS_BT_A) },
  
  	/* Generic Bluetooth Type-B SDIO device */
  	{ SDIO_DEVICE_CLASS(SDIO_CLASS_BT_B) },

  	/* Generic Bluetooth AMP controller */
  	{ SDIO_DEVICE_CLASS(SDIO_CLASS_BT_AMP) },

  	{ }	/* Terminating entry */
  };
  
  MODULE_DEVICE_TABLE(sdio, btsdio_table);
  
  struct btsdio_data {
  	struct hci_dev   *hdev;
  	struct sdio_func *func;
  
  	struct work_struct work;
  
  	struct sk_buff_head txq;
  };
  
  #define REG_RDAT     0x00	/* Receiver Data */
  #define REG_TDAT     0x00	/* Transmitter Data */
  #define REG_PC_RRT   0x10	/* Read Packet Control */
  #define REG_PC_WRT   0x11	/* Write Packet Control */
  #define REG_RTC_STAT 0x12	/* Retry Control Status */
  #define REG_RTC_SET  0x12	/* Retry Control Set */
  #define REG_INTRD    0x13	/* Interrupt Indication */
  #define REG_CL_INTRD 0x13	/* Interrupt Clear */
  #define REG_EN_INTRD 0x14	/* Interrupt Enable */
  #define REG_MD_STAT  0x20	/* Bluetooth Mode Status */

  #define REG_MD_SET   0x20	/* Bluetooth Mode Set */

  
  static int btsdio_tx_packet(struct btsdio_data *data, struct sk_buff *skb)
  {
  	int err;
  
  	BT_DBG("%s", data->hdev->name);
  
  	/* Prepend Type-A header */
  	skb_push(skb, 4);
  	skb->data[0] = (skb->len & 0x0000ff);
  	skb->data[1] = (skb->len & 0x00ff00) >> 8;
  	skb->data[2] = (skb->len & 0xff0000) >> 16;

  	skb->data[3] = hci_skb_pkt_type(skb);

  
  	err = sdio_writesb(data->func, REG_TDAT, skb->data, skb->len);
  	if (err < 0) {

  		skb_pull(skb, 4);

  		sdio_writeb(data->func, 0x01, REG_PC_WRT, NULL);
  		return err;
  	}
  
  	data->hdev->stat.byte_tx += skb->len;
  
  	kfree_skb(skb);
  
  	return 0;
  }
  
  static void btsdio_work(struct work_struct *work)
  {
  	struct btsdio_data *data = container_of(work, struct btsdio_data, work);
  	struct sk_buff *skb;
  	int err;
  
  	BT_DBG("%s", data->hdev->name);
  
  	sdio_claim_host(data->func);
  
  	while ((skb = skb_dequeue(&data->txq))) {
  		err = btsdio_tx_packet(data, skb);
  		if (err < 0) {
  			data->hdev->stat.err_tx++;
  			skb_queue_head(&data->txq, skb);
  			break;
  		}
  	}
  
  	sdio_release_host(data->func);
  }
  
  static int btsdio_rx_packet(struct btsdio_data *data)
  {
  	u8 hdr[4] __attribute__ ((aligned(4)));
  	struct sk_buff *skb;
  	int err, len;
  
  	BT_DBG("%s", data->hdev->name);
  
  	err = sdio_readsb(data->func, hdr, REG_RDAT, 4);
  	if (err < 0)
  		return err;
  
  	len = hdr[0] | (hdr[1] << 8) | (hdr[2] << 16);
  	if (len < 4 || len > 65543)
  		return -EILSEQ;
  
  	skb = bt_skb_alloc(len - 4, GFP_KERNEL);
  	if (!skb) {
  		/* Out of memory. Prepare a read retry and just
  		 * return with the expectation that the next time
  		 * we're called we'll have more memory. */
  		return -ENOMEM;
  	}
  
  	skb_put(skb, len - 4);
  
  	err = sdio_readsb(data->func, skb->data, REG_RDAT, len - 4);
  	if (err < 0) {

  		kfree_skb(skb);

  		return err;
  	}
  
  	data->hdev->stat.byte_rx += len;

  	hci_skb_pkt_type(skb) = hdr[3];

  	err = hci_recv_frame(data->hdev, skb);

  	if (err < 0)

  		return err;

  
  	sdio_writeb(data->func, 0x00, REG_PC_RRT, NULL);
  
  	return 0;
  }
  
  static void btsdio_interrupt(struct sdio_func *func)
  {
  	struct btsdio_data *data = sdio_get_drvdata(func);
  	int intrd;
  
  	BT_DBG("%s", data->hdev->name);
  
  	intrd = sdio_readb(func, REG_INTRD, NULL);
  	if (intrd & 0x01) {
  		sdio_writeb(func, 0x01, REG_CL_INTRD, NULL);
  
  		if (btsdio_rx_packet(data) < 0) {
  			data->hdev->stat.err_rx++;
  			sdio_writeb(data->func, 0x01, REG_PC_RRT, NULL);
  		}
  	}
  }
  
  static int btsdio_open(struct hci_dev *hdev)
  {

  	struct btsdio_data *data = hci_get_drvdata(hdev);

  	int err;
  
  	BT_DBG("%s", hdev->name);

  	sdio_claim_host(data->func);
  
  	err = sdio_enable_func(data->func);

  	if (err < 0)

  		goto release;

  
  	err = sdio_claim_irq(data->func, btsdio_interrupt);
  	if (err < 0) {
  		sdio_disable_func(data->func);

  		goto release;
  	}
  
  	if (data->func->class == SDIO_CLASS_BT_B)

  		sdio_writeb(data->func, 0x00, REG_MD_SET, NULL);

  
  	sdio_writeb(data->func, 0x01, REG_EN_INTRD, NULL);
  
  release:
  	sdio_release_host(data->func);
  
  	return err;
  }
  
  static int btsdio_close(struct hci_dev *hdev)
  {

  	struct btsdio_data *data = hci_get_drvdata(hdev);

  
  	BT_DBG("%s", hdev->name);

  	sdio_claim_host(data->func);
  
  	sdio_writeb(data->func, 0x00, REG_EN_INTRD, NULL);
  
  	sdio_release_irq(data->func);
  	sdio_disable_func(data->func);
  
  	sdio_release_host(data->func);
  
  	return 0;
  }
  
  static int btsdio_flush(struct hci_dev *hdev)
  {

  	struct btsdio_data *data = hci_get_drvdata(hdev);

  
  	BT_DBG("%s", hdev->name);
  
  	skb_queue_purge(&data->txq);
  
  	return 0;
  }

  static int btsdio_send_frame(struct hci_dev *hdev, struct sk_buff *skb)

  {

  	struct btsdio_data *data = hci_get_drvdata(hdev);

  
  	BT_DBG("%s", hdev->name);

  	switch (hci_skb_pkt_type(skb)) {

  	case HCI_COMMAND_PKT:
  		hdev->stat.cmd_tx++;
  		break;
  
  	case HCI_ACLDATA_PKT:
  		hdev->stat.acl_tx++;
  		break;
  
  	case HCI_SCODATA_PKT:
  		hdev->stat.sco_tx++;
  		break;
  
  	default:
  		return -EILSEQ;
  	}
  
  	skb_queue_tail(&data->txq, skb);
  
  	schedule_work(&data->work);
  
  	return 0;
  }

  static int btsdio_probe(struct sdio_func *func,
  				const struct sdio_device_id *id)
  {
  	struct btsdio_data *data;
  	struct hci_dev *hdev;
  	struct sdio_func_tuple *tuple = func->tuples;
  	int err;
  
  	BT_DBG("func %p id %p class 0x%04x", func, id, func->class);
  
  	while (tuple) {
  		BT_DBG("code 0x%x size %d", tuple->code, tuple->size);
  		tuple = tuple->next;
  	}

  	data = devm_kzalloc(&func->dev, sizeof(*data), GFP_KERNEL);

  	if (!data)
  		return -ENOMEM;
  
  	data->func = func;
  
  	INIT_WORK(&data->work, btsdio_work);
  
  	skb_queue_head_init(&data->txq);
  
  	hdev = hci_alloc_dev();

  	if (!hdev)

  		return -ENOMEM;

  	hdev->bus = HCI_SDIO;

  	hci_set_drvdata(hdev, data);

  	if (id->class == SDIO_CLASS_BT_AMP)
  		hdev->dev_type = HCI_AMP;
  	else
  		hdev->dev_type = HCI_BREDR;

  	data->hdev = hdev;
  
  	SET_HCIDEV_DEV(hdev, &func->dev);
  
  	hdev->open     = btsdio_open;
  	hdev->close    = btsdio_close;
  	hdev->flush    = btsdio_flush;
  	hdev->send     = btsdio_send_frame;

  	if (func->vendor == 0x0104 && func->device == 0x00c5)
  		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);

  	err = hci_register_dev(hdev);
  	if (err < 0) {
  		hci_free_dev(hdev);

  		return err;
  	}
  
  	sdio_set_drvdata(func, data);
  
  	return 0;
  }
  
  static void btsdio_remove(struct sdio_func *func)
  {
  	struct btsdio_data *data = sdio_get_drvdata(func);
  	struct hci_dev *hdev;
  
  	BT_DBG("func %p", func);
  
  	if (!data)
  		return;
  
  	hdev = data->hdev;
  
  	sdio_set_drvdata(func, NULL);
  
  	hci_unregister_dev(hdev);
  
  	hci_free_dev(hdev);
  }
  
  static struct sdio_driver btsdio_driver = {
  	.name		= "btsdio",
  	.probe		= btsdio_probe,
  	.remove		= btsdio_remove,
  	.id_table	= btsdio_table,
  };
  
  static int __init btsdio_init(void)
  {
  	BT_INFO("Generic Bluetooth SDIO driver ver %s", VERSION);
  
  	return sdio_register_driver(&btsdio_driver);
  }
  
  static void __exit btsdio_exit(void)
  {
  	sdio_unregister_driver(&btsdio_driver);
  }
  
  module_init(btsdio_init);
  module_exit(btsdio_exit);
  
  MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
  MODULE_DESCRIPTION("Generic Bluetooth SDIO driver ver " VERSION);
  MODULE_VERSION(VERSION);
  MODULE_LICENSE("GPL");