btuart_cs.c

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/*
 *
 *  Driver for Bluetooth PCMCIA cards with HCI UART interface
 *
 *  Copyright (C) 2001-2002  Marcel Holtmann <[email protected]>
 *
 *
 *  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
 *  <[email protected]>.  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 <[email protected]>");
MODULE_DESCRIPTION("Bluetooth driver for Bluetooth PCMCIA cards with HCI UART interface");
MODULE_LICENSE("GPL");



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


typedef struct btuart_info_t {
    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;
} btuart_info_t;


static int btuart_config(struct pcmcia_device *link);
static void btuart_release(struct pcmcia_device *link);

static void btuart_detach(struct pcmcia_device *p_dev);


/* Maximum baud rate */
#define SPEED_MAX  115200

/* Default baud rate: 57600, 115200, 230400 or 460800 */
#define DEFAULT_BAUD_RATE  115200


/* 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



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


static int btuart_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 btuart_write_wakeup(btuart_info_t *info)
{
    if (!info) {
        BT_ERR("Unknown device");
        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;

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

        /* Send frame */
        len = btuart_write(iobase, 16, skb->data, skb->len);
        set_bit(XMIT_WAKEUP, &(info->tx_state));

        if (len == skb->len) {
            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 btuart_receive(btuart_info_t *info)
{
    unsigned int iobase;
    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_state = RECV_WAIT_PACKET_TYPE;
            info->rx_count = 0;
            if (!(info->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC))) {
                BT_ERR("Can't allocate mem for new packet");
                return;
            }
        }

        if (info->rx_state == RECV_WAIT_PACKET_TYPE) {

            info->rx_skb->dev = (void *) info->hdev;
            bt_cb(info->rx_skb)->pkt_type = inb(iobase + UART_RX);

            switch (bt_cb(info->rx_skb)->pkt_type) {

            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", bt_cb(info->rx_skb)->pkt_type);
                info->hdev->stat.err_rx++;
                clear_bit(HCI_RUNNING, &(info->hdev->flags));

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

            }

        } else {

            *skb_put(info->rx_skb, 1) = inb(iobase + UART_RX);
            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->rx_skb);
                    info->rx_skb = NULL;
                    break;

                }

            }

        }

        /* Make sure we don't stay here too long */
        if (boguscount++ > 16)
            break;

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


static irqreturn_t btuart_interrupt(int irq, void *dev_inst)
{
    btuart_info_t *info = dev_inst;
    unsigned int iobase;
    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 */
            btuart_receive(info);
            break;
        case UART_IIR_THRI:
            if (lsr & UART_LSR_THRE) {
                /* Transmitter ready for data */
                btuart_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;

    }

    spin_unlock(&(info->lock));

    return r;
}


static void btuart_change_speed(btuart_info_t *info, unsigned int speed)
{
    unsigned long flags;
    unsigned int iobase;
    int fcr;        /* FIFO control reg */
    int lcr;        /* Line control reg */
    int divisor;

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

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

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

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

    divisor = SPEED_MAX / speed;

    fcr = UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT;

    /* 
     * Use trigger level 1 to avoid 3 ms. timeout delay at 9600 bps, and
     * almost 1,7 ms at 19200 bps. At speeds above that we can just forget
     * about this timeout since it will always be fast enough. 
     */

    if (speed < 38400)
        fcr |= UART_FCR_TRIGGER_1;
    else
        fcr |= UART_FCR_TRIGGER_14;

    /* Bluetooth cards use 8N1 */
    lcr = UART_LCR_WLEN8;

    outb(UART_LCR_DLAB | lcr, iobase + UART_LCR);   /* Set DLAB */
    outb(divisor & 0xff, iobase + UART_DLL);    /* Set speed */
    outb(divisor >> 8, iobase + UART_DLM);
    outb(lcr, iobase + UART_LCR);   /* Set 8N1  */
    outb(fcr, iobase + UART_FCR);   /* Enable FIFO's */

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

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



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


static int btuart_hci_flush(struct hci_dev *hdev)
{
    btuart_info_t *info = hci_get_drvdata(hdev);

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

    return 0;
}


static int btuart_hci_open(struct hci_dev *hdev)
{
    set_bit(HCI_RUNNING, &(hdev->flags));

    return 0;
}


static int btuart_hci_close(struct hci_dev *hdev)
{
    if (!test_and_clear_bit(HCI_RUNNING, &(hdev->flags)))
        return 0;

    btuart_hci_flush(hdev);

    return 0;
}


static int btuart_hci_send_frame(struct sk_buff *skb)
{
    btuart_info_t *info;
    struct hci_dev *hdev = (struct hci_dev *)(skb->dev);

    if (!hdev) {
        BT_ERR("Frame for unknown HCI device (hdev=NULL)");
        return -ENODEV;
    }

    info = hci_get_drvdata(hdev);

    switch (bt_cb(skb)->pkt_type) {
    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), &bt_cb(skb)->pkt_type, 1);
    skb_queue_tail(&(info->txq), skb);

    btuart_write_wakeup(info);

    return 0;
}


static int btuart_hci_ioctl(struct hci_dev *hdev, unsigned int cmd, unsigned long arg)
{
    return -ENOIOCTLCMD;
}



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


static int btuart_open(btuart_info_t *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_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     = btuart_hci_open;
    hdev->close    = btuart_hci_close;
    hdev->flush    = btuart_hci_flush;
    hdev->send     = btuart_hci_send_frame;
    hdev->ioctl    = btuart_hci_ioctl;

    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);

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

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

    btuart_change_speed(info, DEFAULT_BAUD_RATE);

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

    /* 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 btuart_close(btuart_info_t *info)
{
    unsigned long flags;
    unsigned int iobase = info->p_dev->resource[0]->start;
    struct hci_dev *hdev = info->hdev;

    if (!hdev)
        return -ENODEV;

    btuart_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 btuart_probe(struct pcmcia_device *link)
{
    btuart_info_t *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 btuart_config(link);
}


static void btuart_detach(struct pcmcia_device *link)
{
    btuart_release(link);
}

static int btuart_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 btuart_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 btuart_config(struct pcmcia_device *link)
{
    btuart_info_t *info = link->priv;
    int i;
    int 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, btuart_check_config, &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, btuart_check_config_notpicky, NULL))
        goto found_port;

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

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

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

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

    return 0;

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


static void btuart_release(struct pcmcia_device *link)
{
    btuart_info_t *info = link->priv;

    btuart_close(info);

    pcmcia_disable_device(link);
}

static const struct pcmcia_device_id btuart_ids[] = {
    /* don't use this driver. Use serial_cs + hci_uart instead */
    PCMCIA_DEVICE_NULL
};
MODULE_DEVICE_TABLE(pcmcia, btuart_ids);

static struct pcmcia_driver btuart_driver = {
    .owner      = THIS_MODULE,
    .name       = "btuart_cs",
    .probe      = btuart_probe,
    .remove     = btuart_detach,
    .id_table   = btuart_ids,
};

static int __init init_btuart_cs(void)
{
    return pcmcia_register_driver(&btuart_driver);
}


static void __exit exit_btuart_cs(void)
{
    pcmcia_unregister_driver(&btuart_driver);
}

module_init(init_btuart_cs);
module_exit(exit_btuart_cs);