btsdio.c

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/*
 *
 *  Generic Bluetooth SDIO driver
 *
 *  Copyright (C) 2007  Cambridge Silicon Radio Ltd.
 *  Copyright (C) 2007  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 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 */

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] = bt_cb(skb)->pkt_type;

    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;

    skb->dev = (void *) data->hdev;
    bt_cb(skb)->pkt_type = hdr[3];

    err = hci_recv_frame(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);

    if (test_and_set_bit(HCI_RUNNING, &hdev->flags))
        return 0;

    sdio_claim_host(data->func);

    err = sdio_enable_func(data->func);
    if (err < 0) {
        clear_bit(HCI_RUNNING, &hdev->flags);
        goto release;
    }

    err = sdio_claim_irq(data->func, btsdio_interrupt);
    if (err < 0) {
        sdio_disable_func(data->func);
        clear_bit(HCI_RUNNING, &hdev->flags);
        goto release;
    }

    if (data->func->class == SDIO_CLASS_BT_B)
        sdio_writeb(data->func, 0x00, REG_MD_STAT, 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);

    if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
        return 0;

    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 sk_buff *skb)
{
    struct hci_dev *hdev = (struct hci_dev *) skb->dev;
    struct btsdio_data *data = hci_get_drvdata(hdev);

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

    if (!test_bit(HCI_RUNNING, &hdev->flags))
        return -EBUSY;

    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;

    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;

    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 <[email protected]>");
MODULE_DESCRIPTION("Generic Bluetooth SDIO driver ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");