/*
 *
 *  A driver for Nokia Connectivity Card DTL-1 devices
 *
 *  Copyright (C) 2001-2002  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 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 <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 Nokia Connectivity Card DTL-1");
MODULE_LICENSE("GPL");



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


struct dtl1_info {
        struct pcmcia_device *p_dev;

        struct hci_dev *hdev;

        spinlock_t lock;                /* For serializing operations */

        unsigned long flowmask;         /* HCI flow mask */
        int ri_latch;

        struct sk_buff_head txq;
        unsigned long tx_state;

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


static int dtl1_config(struct pcmcia_device *link);


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

/* Receiver States */
#define RECV_WAIT_NSH   0
#define RECV_WAIT_DATA  1


struct nsh {
        u8 type;
        u8 zero;
        u16 len;
} __packed;     /* Nokia Specific Header */

#define NSHL  4                         /* Nokia Specific Header Length */



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


static int dtl1_write(unsigned int iobase, int fifo_size, __u8 *buf, int len)
{
        int actual = 0;

        /* Tx FIFO should be empty */
        if (!(inb(iobase + UART_LSR) & UART_LSR_THRE))
                return 0;

        /* Fill FIFO with current frame */
        while ((fifo_size-- > 0) && (actual < len)) {
                /* Transmit next byte */
                outb(buf[actual], iobase + UART_TX);
                actual++;
        }

        return actual;
}


static void dtl1_write_wakeup(struct dtl1_info *info)
{
        if (!info) {
                BT_ERR("Unknown device");
                return;
        }

        if (test_bit(XMIT_WAITING, &(info->tx_state))) {
                set_bit(XMIT_WAKEUP, &(info->tx_state));
                return;
        }

        if (test_and_set_bit(XMIT_SENDING, &(info->tx_state))) {
                set_bit(XMIT_WAKEUP, &(info->tx_state));
                return;
        }

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

                clear_bit(XMIT_WAKEUP, &(info->tx_state));

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

                skb = skb_dequeue(&(info->txq));
                if (!skb)
                        break;

                /* Send frame */
                len = dtl1_write(iobase, 32, skb->data, skb->len);

                if (len == skb->len) {
                        set_bit(XMIT_WAITING, &(info->tx_state));
                        kfree_skb(skb);
                } else {
                        skb_pull(skb, len);
                        skb_queue_head(&(info->txq), skb);
                }

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

        } while (test_bit(XMIT_WAKEUP, &(info->tx_state)));

        clear_bit(XMIT_SENDING, &(info->tx_state));
}


static void dtl1_control(struct dtl1_info *info, struct sk_buff *skb)
{
        u8 flowmask = *(u8 *)skb->data;
        int i;

        printk(KERN_INFO "Bluetooth: Nokia control data =");
        for (i = 0; i < skb->len; i++)
                printk(" %02x", skb->data[i]);

        printk("\n");

        /* transition to active state */
        if (((info->flowmask & 0x07) == 0) && ((flowmask & 0x07) != 0)) {
                clear_bit(XMIT_WAITING, &(info->tx_state));
                dtl1_write_wakeup(info);
        }

        info->flowmask = flowmask;

        kfree_skb(skb);
}


static void dtl1_receive(struct dtl1_info *info)
{
        unsigned int iobase;
        struct nsh *nsh;
        int boguscount = 0;

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

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

        do {
                info->hdev->stat.byte_rx++;

                /* Allocate packet */
                if (info->rx_skb == NULL) {
                        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");
                                info->rx_state = RECV_WAIT_NSH;
                                info->rx_count = NSHL;
                                return;
                        }
                }

                skb_put_u8(info->rx_skb, inb(iobase + UART_RX));
                nsh = (struct nsh *)info->rx_skb->data;

                info->rx_count--;

                if (info->rx_count == 0) {

                        switch (info->rx_state) {
                        case RECV_WAIT_NSH:
                                info->rx_state = RECV_WAIT_DATA;
                                info->rx_count = nsh->len + (nsh->len & 0x0001);
                                break;
                        case RECV_WAIT_DATA:
                                hci_skb_pkt_type(info->rx_skb) = nsh->type;

                                /* remove PAD byte if it exists */
                                if (nsh->len & 0x0001) {
                                        info->rx_skb->tail--;
                                        info->rx_skb->len--;
                                }

                                /* remove NSH */
                                skb_pull(info->rx_skb, NSHL);

                                switch (hci_skb_pkt_type(info->rx_skb)) {
                                case 0x80:
                                        /* control data for the Nokia Card */
                                        dtl1_control(info, info->rx_skb);
                                        break;
                                case 0x82:
                                case 0x83:
                                case 0x84:
                                        /* send frame to the HCI layer */
                                        hci_skb_pkt_type(info->rx_skb) &= 0x0f;
                                        hci_recv_frame(info->hdev, info->rx_skb);
                                        break;
                                default:
                                        /* unknown packet */
                                        BT_ERR("Unknown HCI packet with type 0x%02x received",
                                               hci_skb_pkt_type(info->rx_skb));
                                        kfree_skb(info->rx_skb);
                                        break;
                                }

                                info->rx_state = RECV_WAIT_NSH;
                                info->rx_count = NSHL;
                                info->rx_skb = NULL;
                                break;
                        }

                }

                /* Make sure we don't stay here too long */
                if (boguscount++ > 32)
                        break;

        } while (inb(iobase + UART_LSR) & UART_LSR_DR);
}


static irqreturn_t dtl1_interrupt(int irq, void *dev_inst)
{
        struct dtl1_info *info = dev_inst;
        unsigned int iobase;
        unsigned char msr;
        int boguscount = 0;
        int iir, lsr;
        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 + UART_IIR) & UART_IIR_ID;
        while (iir) {

                r = IRQ_HANDLED;
                /* Clear interrupt */
                lsr = inb(iobase + UART_LSR);

                switch (iir) {
                case UART_IIR_RLSI:
                        BT_ERR("RLSI");
                        break;
                case UART_IIR_RDI:
                        /* Receive interrupt */
                        dtl1_receive(info);
                        break;
                case UART_IIR_THRI:
                        if (lsr & UART_LSR_THRE) {
                                /* Transmitter ready for data */
                                dtl1_write_wakeup(info);
                        }
                        break;
                default:
                        BT_ERR("Unhandled IIR=%#x", iir);
                        break;
                }

                /* Make sure we don't stay here too long */
                if (boguscount++ > 100)
                        break;

                iir = inb(iobase + UART_IIR) & UART_IIR_ID;

        }

        msr = inb(iobase + UART_MSR);

        if (info->ri_latch ^ (msr & UART_MSR_RI)) {
                info->ri_latch = msr & UART_MSR_RI;
                clear_bit(XMIT_WAITING, &(info->tx_state));
                dtl1_write_wakeup(info);
                r = IRQ_HANDLED;
        }

        spin_unlock(&(info->lock));

        return r;
}



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


static int dtl1_hci_open(struct hci_dev *hdev)
{
        return 0;
}


static int dtl1_hci_flush(struct hci_dev *hdev)
{
        struct dtl1_info *info = hci_get_drvdata(hdev);

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

        return 0;
}


static int dtl1_hci_close(struct hci_dev *hdev)
{
        dtl1_hci_flush(hdev);

        return 0;
}


static int dtl1_hci_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct dtl1_info *info = hci_get_drvdata(hdev);
        struct sk_buff *s;
        struct nsh nsh;

        switch (hci_skb_pkt_type(skb)) {
        case HCI_COMMAND_PKT:
                hdev->stat.cmd_tx++;
                nsh.type = 0x81;
                break;
        case HCI_ACLDATA_PKT:
                hdev->stat.acl_tx++;
                nsh.type = 0x82;
                break;
        case HCI_SCODATA_PKT:
                hdev->stat.sco_tx++;
                nsh.type = 0x83;
                break;
        default:
                return -EILSEQ;
        }

        nsh.zero = 0;
        nsh.len = skb->len;

        s = bt_skb_alloc(NSHL + skb->len + 1, GFP_ATOMIC);
        if (!s)
                return -ENOMEM;

        skb_reserve(s, NSHL);
        skb_copy_from_linear_data(skb, skb_put(s, skb->len), skb->len);
        if (skb->len & 0x0001)
                skb_put_u8(s, 0);       /* PAD */

        /* Prepend skb with Nokia frame header and queue */
        memcpy(skb_push(s, NSHL), &nsh, NSHL);
        skb_queue_tail(&(info->txq), s);

        dtl1_write_wakeup(info);

        kfree_skb(skb);

        return 0;
}



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


static int dtl1_open(struct dtl1_info *info)
{
        unsigned long flags;
        unsigned int iobase = info->p_dev->resource[0]->start;
        struct hci_dev *hdev;

        spin_lock_init(&(info->lock));

        skb_queue_head_init(&(info->txq));

        info->rx_state = RECV_WAIT_NSH;
        info->rx_count = NSHL;
        info->rx_skb = NULL;

        set_bit(XMIT_WAITING, &(info->tx_state));

        /* 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  = dtl1_hci_open;
        hdev->close = dtl1_hci_close;
        hdev->flush = dtl1_hci_flush;
        hdev->send  = dtl1_hci_send_frame;

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

        /* Reset UART */
        outb(0, iobase + UART_MCR);

        /* Turn off interrupts */
        outb(0, iobase + UART_IER);

        /* Initialize UART */
        outb(UART_LCR_WLEN8, iobase + UART_LCR);        /* Reset DLAB */
        outb((UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2), iobase + UART_MCR);

        info->ri_latch = inb(info->p_dev->resource[0]->start + UART_MSR)
                                & UART_MSR_RI;

        /* Turn on interrupts */
        outb(UART_IER_RLSI | UART_IER_RDI | UART_IER_THRI, iobase + UART_IER);

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

        /* Timeout before it is safe to send the first HCI packet */
        msleep(2000);

        /* Register HCI device */
        if (hci_register_dev(hdev) < 0) {
                BT_ERR("Can't register HCI device");
                info->hdev = NULL;
                hci_free_dev(hdev);
                return -ENODEV;
        }

        return 0;
}


static int dtl1_close(struct dtl1_info *info)
{
        unsigned long flags;
        unsigned int iobase = info->p_dev->resource[0]->start;
        struct hci_dev *hdev = info->hdev;

        if (!hdev)
                return -ENODEV;

        dtl1_hci_close(hdev);

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

        /* Reset UART */
        outb(0, iobase + UART_MCR);

        /* Turn off interrupts */
        outb(0, iobase + UART_IER);

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

        hci_unregister_dev(hdev);
        hci_free_dev(hdev);

        return 0;
}

static int dtl1_probe(struct pcmcia_device *link)
{
        struct dtl1_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_IO;

        return dtl1_config(link);
}


static void dtl1_detach(struct pcmcia_device *link)
{
        struct dtl1_info *info = link->priv;

        dtl1_close(info);
        pcmcia_disable_device(link);
}

static int dtl1_confcheck(struct pcmcia_device *p_dev, void *priv_data)
{
        if ((p_dev->resource[1]->end) || (p_dev->resource[1]->end < 8))
                return -ENODEV;

        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 dtl1_config(struct pcmcia_device *link)
{
        struct dtl1_info *info = link->priv;
        int ret;

        /* Look for a generic full-sized window */
        link->resource[0]->end = 8;
        ret = pcmcia_loop_config(link, dtl1_confcheck, NULL);
        if (ret)
                goto failed;

        ret = pcmcia_request_irq(link, dtl1_interrupt);
        if (ret)
                goto failed;

        ret = pcmcia_enable_device(link);
        if (ret)
                goto failed;

        ret = dtl1_open(info);
        if (ret)
                goto failed;

        return 0;

failed:
        dtl1_detach(link);
        return ret;
}

static const struct pcmcia_device_id dtl1_ids[] = {
        PCMCIA_DEVICE_PROD_ID12("Nokia Mobile Phones", "DTL-1", 0xe1bfdd64, 0xe168480d),
        PCMCIA_DEVICE_PROD_ID12("Nokia Mobile Phones", "DTL-4", 0xe1bfdd64, 0x9102bc82),
        PCMCIA_DEVICE_PROD_ID12("Socket", "CF", 0xb38bcc2e, 0x44ebf863),
        PCMCIA_DEVICE_PROD_ID12("Socket", "CF+ Personal Network Card", 0xb38bcc2e, 0xe732bae3),
        PCMCIA_DEVICE_NULL
};
MODULE_DEVICE_TABLE(pcmcia, dtl1_ids);

static struct pcmcia_driver dtl1_driver = {
        .owner          = THIS_MODULE,
        .name           = "dtl1_cs",
        .probe          = dtl1_probe,
        .remove         = dtl1_detach,
        .id_table       = dtl1_ids,
};
module_pcmcia_driver(dtl1_driver);