/*
 *
 *  Driver for the 3Com Bluetooth PCMCIA card
 *
 *  Copyright (C) 2001-2002  Marcel Holtmann <marcel@holtmann.org>
 *                           Jose Orlando Pereira <jop@di.uminho.pt>
 *
 *
 *  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;
 *
 *  Software distributed under the License is distributed on an "AS
 *  IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 *  implied. See the License for the specific language governing
 *  rights and limitations under the License.
 *
 *  The initial developer of the original code is David A. Hinds
 *  <dahinds@users.sourceforge.net>.  Portions created by David A. Hinds
 *  are Copyright (C) 1999 David A. Hinds.  All Rights Reserved.
 *
 */

#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/spinlock.h>
#include <linux/moduleparam.h>

#include <linux/skbuff.h>
#include <linux/string.h>
#include <linux/serial.h>
#include <linux/serial_reg.h>
#include <linux/bitops.h>
#include <asm/io.h>

#include <linux/device.h>
#include <linux/firmware.h>

#include <pcmcia/cistpl.h>
#include <pcmcia/ciscode.h>
#include <pcmcia/ds.h>
#include <pcmcia/cisreg.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>


/* ======================== Module parameters ======================== */


MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
MODULE_DESCRIPTION("Bluetooth driver for the 3Com Bluetooth PCMCIA card");
MODULE_LICENSE("GPL");
MODULE_FIRMWARE("BT3CPCC.bin");


/* ======================== Local structures ======================== */


struct bt3c_info {
	struct pcmcia_device *p_dev;

	struct hci_dev *hdev;

	spinlock_t lock;		/* For serializing operations */

	struct sk_buff_head txq;
	unsigned long tx_state;

	unsigned long rx_state;
	unsigned long rx_count;
	struct sk_buff *rx_skb;
};


static int bt3c_config(struct pcmcia_device *link);
static void bt3c_release(struct pcmcia_device *link);

static void bt3c_detach(struct pcmcia_device *p_dev);


/* Transmit states  */
#define XMIT_SENDING  1
#define XMIT_WAKEUP   2
#define XMIT_WAITING  8

/* Receiver states */
#define RECV_WAIT_PACKET_TYPE   0
#define RECV_WAIT_EVENT_HEADER  1
#define RECV_WAIT_ACL_HEADER    2
#define RECV_WAIT_SCO_HEADER    3
#define RECV_WAIT_DATA          4


/* ======================== Special I/O functions ======================== */


#define DATA_L   0
#define DATA_H   1
#define ADDR_L   2
#define ADDR_H   3
#define CONTROL  4


static inline void bt3c_address(unsigned int iobase, unsigned short addr)
{
	outb(addr & 0xff, iobase + ADDR_L);
	outb((addr >> 8) & 0xff, iobase + ADDR_H);
}


static inline void bt3c_put(unsigned int iobase, unsigned short value)
{
	outb(value & 0xff, iobase + DATA_L);
	outb((value >> 8) & 0xff, iobase + DATA_H);
}


static inline void bt3c_io_write(unsigned int iobase, unsigned short addr, unsigned short value)
{
	bt3c_address(iobase, addr);
	bt3c_put(iobase, value);
}


static inline unsigned short bt3c_get(unsigned int iobase)
{
	unsigned short value = inb(iobase + DATA_L);

	value |= inb(iobase + DATA_H) << 8;

	return value;
}


static inline unsigned short bt3c_read(unsigned int iobase, unsigned short addr)
{
	bt3c_address(iobase, addr);

	return bt3c_get(iobase);
}


/* ======================== Interrupt handling ======================== */


static int bt3c_write(unsigned int iobase, int fifo_size, __u8 *buf, int len)
{
	int actual = 0;

	bt3c_address(iobase, 0x7080);

	/* Fill FIFO with current frame */
	while (actual < len) {
		/* Transmit next byte */
		bt3c_put(iobase, buf[actual]);
		actual++;
	}

	bt3c_io_write(iobase, 0x7005, actual);

	return actual;
}


static void bt3c_write_wakeup(struct bt3c_info *info)
{
	if (!info) {
		BT_ERR("Unknown device");
		return;
	}

	if (test_and_set_bit(XMIT_SENDING, &(info->tx_state)))
		return;

	do {
		unsigned int iobase = info->p_dev->resource[0]->start;
		register struct sk_buff *skb;
		int len;

		if (!pcmcia_dev_present(info->p_dev))
			break;

		skb = skb_dequeue(&(info->txq));
		if (!skb) {
			clear_bit(XMIT_SENDING, &(info->tx_state));
			break;
		}

		/* Send frame */
		len = bt3c_write(iobase, 256, skb->data, skb->len);

		if (len != skb->len)
			BT_ERR("Very strange");

		kfree_skb(skb);

		info->hdev->stat.byte_tx += len;

	} while (0);
}


static void bt3c_receive(struct bt3c_info *info)
{
	unsigned int iobase;
	int size = 0, avail;

	if (!info) {
		BT_ERR("Unknown device");
		return;
	}

	iobase = info->p_dev->resource[0]->start;

	avail = bt3c_read(iobase, 0x7006);

	bt3c_address(iobase, 0x7480);
	while (size < avail) {
		size++;
		info->hdev->stat.byte_rx++;

		/* Allocate packet */
		if (!info->rx_skb) {
			info->rx_state = RECV_WAIT_PACKET_TYPE;
			info->rx_count = 0;
			info->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
			if (!info->rx_skb) {
				BT_ERR("Can't allocate mem for new packet");
				return;
			}
		}


		if (info->rx_state == RECV_WAIT_PACKET_TYPE) {

			hci_skb_pkt_type(info->rx_skb) = inb(iobase + DATA_L);
			inb(iobase + DATA_H);

			switch (hci_skb_pkt_type(info->rx_skb)) {

			case HCI_EVENT_PKT:
				info->rx_state = RECV_WAIT_EVENT_HEADER;
				info->rx_count = HCI_EVENT_HDR_SIZE;
				break;

			case HCI_ACLDATA_PKT:
				info->rx_state = RECV_WAIT_ACL_HEADER;
				info->rx_count = HCI_ACL_HDR_SIZE;
				break;

			case HCI_SCODATA_PKT:
				info->rx_state = RECV_WAIT_SCO_HEADER;
				info->rx_count = HCI_SCO_HDR_SIZE;
				break;

			default:
				/* Unknown packet */
				BT_ERR("Unknown HCI packet with type 0x%02x received",
				       hci_skb_pkt_type(info->rx_skb));
				info->hdev->stat.err_rx++;

				kfree_skb(info->rx_skb);
				info->rx_skb = NULL;
				break;

			}

		} else {

			__u8 x = inb(iobase + DATA_L);

			skb_put_u8(info->rx_skb, x);
			inb(iobase + DATA_H);
			info->rx_count--;

			if (info->rx_count == 0) {

				int dlen;
				struct hci_event_hdr *eh;
				struct hci_acl_hdr *ah;
				struct hci_sco_hdr *sh;

				switch (info->rx_state) {

				case RECV_WAIT_EVENT_HEADER:
					eh = hci_event_hdr(info->rx_skb);
					info->rx_state = RECV_WAIT_DATA;
					info->rx_count = eh->plen;
					break;

				case RECV_WAIT_ACL_HEADER:
					ah = hci_acl_hdr(info->rx_skb);
					dlen = __le16_to_cpu(ah->dlen);
					info->rx_state = RECV_WAIT_DATA;
					info->rx_count = dlen;
					break;

				case RECV_WAIT_SCO_HEADER:
					sh = hci_sco_hdr(info->rx_skb);
					info->rx_state = RECV_WAIT_DATA;
					info->rx_count = sh->dlen;
					break;

				case RECV_WAIT_DATA:
					hci_recv_frame(info->hdev, info->rx_skb);
					info->rx_skb = NULL;
					break;

				}

			}

		}

	}

	bt3c_io_write(iobase, 0x7006, 0x0000);
}


static irqreturn_t bt3c_interrupt(int irq, void *dev_inst)
{
	struct bt3c_info *info = dev_inst;
	unsigned int iobase;
	int iir;
	irqreturn_t r = IRQ_NONE;

	if (!info || !info->hdev)
		/* our irq handler is shared */
		return IRQ_NONE;

	iobase = info->p_dev->resource[0]->start;

	spin_lock(&(info->lock));

	iir = inb(iobase + CONTROL);
	if (iir & 0x80) {
		int stat = bt3c_read(iobase, 0x7001);

		if ((stat & 0xff) == 0x7f) {
			BT_ERR("Very strange (stat=0x%04x)", stat);
		} else if ((stat & 0xff) != 0xff) {
			if (stat & 0x0020) {
				int status = bt3c_read(iobase, 0x7002) & 0x10;
				BT_INFO("%s: Antenna %s", info->hdev->name,
							status ? "out" : "in");
			}
			if (stat & 0x0001)
				bt3c_receive(info);
			if (stat & 0x0002) {
				clear_bit(XMIT_SENDING, &(info->tx_state));
				bt3c_write_wakeup(info);
			}

			bt3c_io_write(iobase, 0x7001, 0x0000);

			outb(iir, iobase + CONTROL);
		}
		r = IRQ_HANDLED;
	}

	spin_unlock(&(info->lock));

	return r;
}


/* ======================== HCI interface ======================== */


static int bt3c_hci_flush(struct hci_dev *hdev)
{
	struct bt3c_info *info = hci_get_drvdata(hdev);

	/* Drop TX queue */
	skb_queue_purge(&(info->txq));

	return 0;
}


static int bt3c_hci_open(struct hci_dev *hdev)
{
	return 0;
}


static int bt3c_hci_close(struct hci_dev *hdev)
{
	bt3c_hci_flush(hdev);

	return 0;
}


static int bt3c_hci_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
{
	struct bt3c_info *info = hci_get_drvdata(hdev);
	unsigned long flags;

	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;
	}

	/* Prepend skb with frame type */
	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
	skb_queue_tail(&(info->txq), skb);

	spin_lock_irqsave(&(info->lock), flags);

	bt3c_write_wakeup(info);

	spin_unlock_irqrestore(&(info->lock), flags);

	return 0;
}


/* ======================== Card services HCI interaction ======================== */


static int bt3c_load_firmware(struct bt3c_info *info,
			      const unsigned char *firmware,
			      int count)
{
	char *ptr = (char *) firmware;
	char b[9];
	unsigned int iobase, tmp;
	unsigned long size, addr, fcs;
	int i, err = 0;

	iobase = info->p_dev->resource[0]->start;

	/* Reset */
	bt3c_io_write(iobase, 0x8040, 0x0404);
	bt3c_io_write(iobase, 0x8040, 0x0400);

	udelay(1);

	bt3c_io_write(iobase, 0x8040, 0x0404);

	udelay(17);

	/* Load */
	while (count) {
		if (ptr[0] != 'S') {
			BT_ERR("Bad address in firmware");
			err = -EFAULT;
			goto error;
		}

		memset(b, 0, sizeof(b));
		memcpy(b, ptr + 2, 2);
		if (kstrtoul(b, 16, &size) < 0)
			return -EINVAL;

		memset(b, 0, sizeof(b));
		memcpy(b, ptr + 4, 8);
		if (kstrtoul(b, 16, &addr) < 0)
			return -EINVAL;

		memset(b, 0, sizeof(b));
		memcpy(b, ptr + (size * 2) + 2, 2);
		if (kstrtoul(b, 16, &fcs) < 0)
			return -EINVAL;

		memset(b, 0, sizeof(b));
		for (tmp = 0, i = 0; i < size; i++) {
			memcpy(b, ptr + (i * 2) + 2, 2);
			tmp += simple_strtol(b, NULL, 16);
		}

		if (((tmp + fcs) & 0xff) != 0xff) {
			BT_ERR("Checksum error in firmware");
			err = -EILSEQ;
			goto error;
		}

		if (ptr[1] == '3') {
			bt3c_address(iobase, addr);

			memset(b, 0, sizeof(b));
			for (i = 0; i < (size - 4) / 2; i++) {
				memcpy(b, ptr + (i * 4) + 12, 4);
				tmp = simple_strtoul(b, NULL, 16);
				bt3c_put(iobase, tmp);
			}
		}

		ptr   += (size * 2) + 6;
		count -= (size * 2) + 6;
	}

	udelay(17);

	/* Boot */
	bt3c_address(iobase, 0x3000);
	outb(inb(iobase + CONTROL) | 0x40, iobase + CONTROL);

error:
	udelay(17);

	/* Clear */
	bt3c_io_write(iobase, 0x7006, 0x0000);
	bt3c_io_write(iobase, 0x7005, 0x0000);
	bt3c_io_write(iobase, 0x7001, 0x0000);

	return err;
}


static int bt3c_open(struct bt3c_info *info)
{
	const struct firmware *firmware;
	struct hci_dev *hdev;
	int err;

	spin_lock_init(&(info->lock));

	skb_queue_head_init(&(info->txq));

	info->rx_state = RECV_WAIT_PACKET_TYPE;
	info->rx_count = 0;
	info->rx_skb = NULL;

	/* Initialize HCI device */
	hdev = hci_alloc_dev();
	if (!hdev) {
		BT_ERR("Can't allocate HCI device");
		return -ENOMEM;
	}

	info->hdev = hdev;

	hdev->bus = HCI_PCCARD;
	hci_set_drvdata(hdev, info);
	SET_HCIDEV_DEV(hdev, &info->p_dev->dev);

	hdev->open  = bt3c_hci_open;
	hdev->close = bt3c_hci_close;
	hdev->flush = bt3c_hci_flush;
	hdev->send  = bt3c_hci_send_frame;

	/* Load firmware */
	err = request_firmware(&firmware, "BT3CPCC.bin", &info->p_dev->dev);
	if (err < 0) {
		BT_ERR("Firmware request failed");
		goto error;
	}

	err = bt3c_load_firmware(info, firmware->data, firmware->size);

	release_firmware(firmware);

	if (err < 0) {
		BT_ERR("Firmware loading failed");
		goto error;
	}

	/* Timeout before it is safe to send the first HCI packet */
	msleep(1000);

	/* Register HCI device */
	err = hci_register_dev(hdev);
	if (err < 0) {
		BT_ERR("Can't register HCI device");
		goto error;
	}

	return 0;

error:
	info->hdev = NULL;
	hci_free_dev(hdev);
	return err;
}


static int bt3c_close(struct bt3c_info *info)
{
	struct hci_dev *hdev = info->hdev;

	if (!hdev)
		return -ENODEV;

	bt3c_hci_close(hdev);

	hci_unregister_dev(hdev);
	hci_free_dev(hdev);

	return 0;
}

static int bt3c_probe(struct pcmcia_device *link)
{
	struct bt3c_info *info;

	/* Create new info device */
	info = devm_kzalloc(&link->dev, sizeof(*info), GFP_KERNEL);
	if (!info)
		return -ENOMEM;

	info->p_dev = link;
	link->priv = info;

	link->config_flags |= CONF_ENABLE_IRQ | CONF_AUTO_SET_VPP |
		CONF_AUTO_SET_IO;

	return bt3c_config(link);
}


static void bt3c_detach(struct pcmcia_device *link)
{
	bt3c_release(link);
}

static int bt3c_check_config(struct pcmcia_device *p_dev, void *priv_data)
{
	int *try = priv_data;

	if (!try)
		p_dev->io_lines = 16;

	if ((p_dev->resource[0]->end != 8) || (p_dev->resource[0]->start == 0))
		return -EINVAL;

	p_dev->resource[0]->end = 8;
	p_dev->resource[0]->flags &= ~IO_DATA_PATH_WIDTH;
	p_dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8;

	return pcmcia_request_io(p_dev);
}

static int bt3c_check_config_notpicky(struct pcmcia_device *p_dev,
				      void *priv_data)
{
	static unsigned int base[5] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8, 0x0 };
	int j;

	if (p_dev->io_lines > 3)
		return -ENODEV;

	p_dev->resource[0]->flags &= ~IO_DATA_PATH_WIDTH;
	p_dev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8;
	p_dev->resource[0]->end = 8;

	for (j = 0; j < 5; j++) {
		p_dev->resource[0]->start = base[j];
		p_dev->io_lines = base[j] ? 16 : 3;
		if (!pcmcia_request_io(p_dev))
			return 0;
	}
	return -ENODEV;
}

static int bt3c_config(struct pcmcia_device *link)
{
	struct bt3c_info *info = link->priv;
	int i;
	unsigned long try;

	/* First pass: look for a config entry that looks normal.
	   Two tries: without IO aliases, then with aliases */
	for (try = 0; try < 2; try++)
		if (!pcmcia_loop_config(link, bt3c_check_config, (void *) try))
			goto found_port;

	/* Second pass: try to find an entry that isn't picky about
	   its base address, then try to grab any standard serial port
	   address, and finally try to get any free port. */
	if (!pcmcia_loop_config(link, bt3c_check_config_notpicky, NULL))
		goto found_port;

	BT_ERR("No usable port range found");
	goto failed;

found_port:
	i = pcmcia_request_irq(link, &bt3c_interrupt);
	if (i != 0)
		goto failed;

	i = pcmcia_enable_device(link);
	if (i != 0)
		goto failed;

	if (bt3c_open(info) != 0)
		goto failed;

	return 0;

failed:
	bt3c_release(link);
	return -ENODEV;
}


static void bt3c_release(struct pcmcia_device *link)
{
	struct bt3c_info *info = link->priv;

	bt3c_close(info);

	pcmcia_disable_device(link);
}


static const struct pcmcia_device_id bt3c_ids[] = {
	PCMCIA_DEVICE_PROD_ID13("3COM", "Bluetooth PC Card", 0xefce0a31, 0xd4ce9b02),
	PCMCIA_DEVICE_NULL
};
MODULE_DEVICE_TABLE(pcmcia, bt3c_ids);

static struct pcmcia_driver bt3c_driver = {
	.owner		= THIS_MODULE,
	.name		= "bt3c_cs",
	.probe		= bt3c_probe,
	.remove		= bt3c_detach,
	.id_table	= bt3c_ids,
};
module_pcmcia_driver(bt3c_driver);