gdm_sdio.c

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/*
 * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * 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.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>

#include <linux/mmc/core.h>
#include <linux/mmc/card.h>
#include <linux/mmc/sdio_func.h>
#include <linux/mmc/sdio_ids.h>

#include "gdm_sdio.h"
#include "gdm_wimax.h"
#include "sdio_boot.h"
#include "hci.h"

#define TYPE_A_HEADER_SIZE  4
#define TYPE_A_LOOKAHEAD_SIZE   16

#define MAX_NR_RX_BUF   4

#define SDU_TX_BUF_SIZE 2048
#define TX_BUF_SIZE     2048
#define TX_CHUNK_SIZE   (2048 - TYPE_A_HEADER_SIZE)
#define RX_BUF_SIZE     (25*1024)

#define TX_HZ   2000
#define TX_INTERVAL (1000000/TX_HZ)

/*#define DEBUG*/

static int init_sdio(struct sdiowm_dev *sdev);
static void release_sdio(struct sdiowm_dev *sdev);

#ifdef DEBUG
static void hexdump(char *title, u8 *data, int len)
{
    int i;

    printk(KERN_DEBUG "%s: length = %d\n", title, len);
    for (i = 0; i < len; i++) {
        printk(KERN_DEBUG "%02x ", data[i]);
        if ((i & 0xf) == 0xf)
            printk(KERN_DEBUG "\n");
    }
    printk(KERN_DEBUG "\n");
}
#endif

static struct sdio_tx *alloc_tx_struct(struct tx_cxt *tx)
{
    struct sdio_tx *t = kzalloc(sizeof(*t), GFP_ATOMIC);

    if (!t)
        return NULL;

    t->buf = kmalloc(TX_BUF_SIZE, GFP_ATOMIC);
    if (!t->buf) {
        kfree(t);
        return NULL;
    }

    t->tx_cxt = tx;

    return t;
}

static void free_tx_struct(struct sdio_tx *t)
{
    if (t) {
        kfree(t->buf);
        kfree(t);
    }
}

static struct sdio_rx *alloc_rx_struct(struct rx_cxt *rx)
{
    struct sdio_rx *r = kzalloc(sizeof(*r), GFP_ATOMIC);

    if (r)
        r->rx_cxt = rx;

    return r;
}

static void free_rx_struct(struct sdio_rx *r)
{
    kfree(r);
}

/* Before this function is called, spin lock should be locked. */
static struct sdio_tx *get_tx_struct(struct tx_cxt *tx, int *no_spc)
{
    struct sdio_tx *t;

    if (list_empty(&tx->free_list))
        return NULL;

    t = list_entry(tx->free_list.prev, struct sdio_tx, list);
    list_del(&t->list);

    *no_spc = list_empty(&tx->free_list) ? 1 : 0;

    return t;
}

/* Before this function is called, spin lock should be locked. */
static void put_tx_struct(struct tx_cxt *tx, struct sdio_tx *t)
{
    list_add_tail(&t->list, &tx->free_list);
}

/* Before this function is called, spin lock should be locked. */
static struct sdio_rx *get_rx_struct(struct rx_cxt *rx)
{
    struct sdio_rx *r;

    if (list_empty(&rx->free_list))
        return NULL;

    r = list_entry(rx->free_list.prev, struct sdio_rx, list);
    list_del(&r->list);

    return r;
}

/* Before this function is called, spin lock should be locked. */
static void put_rx_struct(struct rx_cxt *rx, struct sdio_rx *r)
{
    list_add_tail(&r->list, &rx->free_list);
}

static int init_sdio(struct sdiowm_dev *sdev)
{
    int ret = 0, i;
    struct tx_cxt   *tx = &sdev->tx;
    struct rx_cxt   *rx = &sdev->rx;
    struct sdio_tx  *t;
    struct sdio_rx  *r;

    INIT_LIST_HEAD(&tx->free_list);
    INIT_LIST_HEAD(&tx->sdu_list);
    INIT_LIST_HEAD(&tx->hci_list);

    spin_lock_init(&tx->lock);

    tx->sdu_buf = kmalloc(SDU_TX_BUF_SIZE, GFP_KERNEL);
    if (tx->sdu_buf == NULL) {
        printk(KERN_ERR "Failed to allocate SDU tx buffer.\n");
        goto fail;
    }

    for (i = 0; i < MAX_NR_SDU_BUF; i++) {
        t = alloc_tx_struct(tx);
        if (t == NULL) {
            ret = -ENOMEM;
            goto fail;
        }
        list_add(&t->list, &tx->free_list);
    }

    INIT_LIST_HEAD(&rx->free_list);
    INIT_LIST_HEAD(&rx->req_list);

    spin_lock_init(&rx->lock);

    for (i = 0; i < MAX_NR_RX_BUF; i++) {
        r = alloc_rx_struct(rx);
        if (r == NULL) {
            ret = -ENOMEM;
            goto fail;
        }
        list_add(&r->list, &rx->free_list);
    }

    rx->rx_buf = kmalloc(RX_BUF_SIZE, GFP_KERNEL);
    if (rx->rx_buf == NULL) {
        printk(KERN_ERR "Failed to allocate rx buffer.\n");
        goto fail;
    }

    return 0;

fail:
    release_sdio(sdev);
    return ret;
}

static void release_sdio(struct sdiowm_dev *sdev)
{
    struct tx_cxt   *tx = &sdev->tx;
    struct rx_cxt   *rx = &sdev->rx;
    struct sdio_tx  *t, *t_next;
    struct sdio_rx  *r, *r_next;

    kfree(tx->sdu_buf);

    list_for_each_entry_safe(t, t_next, &tx->free_list, list) {
        list_del(&t->list);
        free_tx_struct(t);
    }

    list_for_each_entry_safe(t, t_next, &tx->sdu_list, list) {
        list_del(&t->list);
        free_tx_struct(t);
    }

    list_for_each_entry_safe(t, t_next, &tx->hci_list, list) {
        list_del(&t->list);
        free_tx_struct(t);
    }

    kfree(rx->rx_buf);

    list_for_each_entry_safe(r, r_next, &rx->free_list, list) {
        list_del(&r->list);
        free_rx_struct(r);
    }

    list_for_each_entry_safe(r, r_next, &rx->req_list, list) {
        list_del(&r->list);
        free_rx_struct(r);
    }
}

static void send_sdio_pkt(struct sdio_func *func, u8 *data, int len)
{
    int n, blocks, ret, remain;

    sdio_claim_host(func);

    blocks = len / func->cur_blksize;
    n = blocks * func->cur_blksize;
    if (blocks) {
        ret = sdio_memcpy_toio(func, 0, data, n);
        if (ret < 0) {
            if (ret != -ENOMEDIUM)
                printk(KERN_ERR "gdmwms: %s error: ret = %d\n",
                    __func__, ret);
            goto end_io;
        }
    }

    remain = len - n;
    remain = (remain + 3) & ~3;

    if (remain) {
        ret = sdio_memcpy_toio(func, 0, data + n, remain);
        if (ret < 0) {
            if (ret != -ENOMEDIUM)
                printk(KERN_ERR "gdmwms: %s error: ret = %d\n",
                    __func__, ret);
            goto end_io;
        }
    }

end_io:
    sdio_release_host(func);
}

static void send_sdu(struct sdio_func *func, struct tx_cxt *tx)
{
    struct list_head *l, *next;
    struct hci_s *hci;
    struct sdio_tx *t;
    int pos, len, i, estlen, aggr_num = 0, aggr_len;
    u8 *buf;
    unsigned long flags;

    spin_lock_irqsave(&tx->lock, flags);

    pos = TYPE_A_HEADER_SIZE + HCI_HEADER_SIZE;
    list_for_each_entry(t, &tx->sdu_list, list) {
        estlen = ((t->len + 3) & ~3) + 4;
        if ((pos + estlen) > SDU_TX_BUF_SIZE)
            break;

        aggr_num++;
        memcpy(tx->sdu_buf + pos, t->buf, t->len);
        memset(tx->sdu_buf + pos + t->len, 0, estlen - t->len);
        pos += estlen;
    }
    aggr_len = pos;

    hci = (struct hci_s *)(tx->sdu_buf + TYPE_A_HEADER_SIZE);
    hci->cmd_evt = H2B(WIMAX_TX_SDU_AGGR);
    hci->length = H2B(aggr_len - TYPE_A_HEADER_SIZE - HCI_HEADER_SIZE);

    spin_unlock_irqrestore(&tx->lock, flags);

#ifdef DEBUG
    hexdump("sdio_send", tx->sdu_buf + TYPE_A_HEADER_SIZE,
        aggr_len - TYPE_A_HEADER_SIZE);
#endif

    for (pos = TYPE_A_HEADER_SIZE; pos < aggr_len; pos += TX_CHUNK_SIZE) {
        len = aggr_len - pos;
        len = len > TX_CHUNK_SIZE ? TX_CHUNK_SIZE : len;
        buf = tx->sdu_buf + pos - TYPE_A_HEADER_SIZE;

        buf[0] = len & 0xff;
        buf[1] = (len >> 8) & 0xff;
        buf[2] = (len >> 16) & 0xff;
        buf[3] = (pos + len) >= aggr_len ? 0 : 1;
        send_sdio_pkt(func, buf, len + TYPE_A_HEADER_SIZE);
    }

    spin_lock_irqsave(&tx->lock, flags);

    for (l = tx->sdu_list.next, i = 0; i < aggr_num; i++, l = next) {
        next = l->next;
        t = list_entry(l, struct sdio_tx, list);
        if (t->callback)
            t->callback(t->cb_data);

        list_del(l);
        put_tx_struct(t->tx_cxt, t);
    }

    do_gettimeofday(&tx->sdu_stamp);
    spin_unlock_irqrestore(&tx->lock, flags);
}

static void send_hci(struct sdio_func *func, struct tx_cxt *tx,
            struct sdio_tx *t)
{
    unsigned long flags;

#ifdef DEBUG
    hexdump("sdio_send", t->buf + TYPE_A_HEADER_SIZE,
        t->len - TYPE_A_HEADER_SIZE);
#endif
    send_sdio_pkt(func, t->buf, t->len);

    spin_lock_irqsave(&tx->lock, flags);
    if (t->callback)
        t->callback(t->cb_data);
    free_tx_struct(t);
    spin_unlock_irqrestore(&tx->lock, flags);
}

static void do_tx(struct work_struct *work)
{
    struct sdiowm_dev *sdev = container_of(work, struct sdiowm_dev, ws);
    struct sdio_func *func = sdev->func;
    struct tx_cxt *tx = &sdev->tx;
    struct sdio_tx *t = NULL;
    struct timeval now, *before;
    int is_sdu = 0;
    long diff;
    unsigned long flags;

    spin_lock_irqsave(&tx->lock, flags);
    if (!tx->can_send) {
        spin_unlock_irqrestore(&tx->lock, flags);
        return;
    }

    if (!list_empty(&tx->hci_list)) {
        t = list_entry(tx->hci_list.next, struct sdio_tx, list);
        list_del(&t->list);
        is_sdu = 0;
    } else if (!tx->stop_sdu_tx && !list_empty(&tx->sdu_list)) {
        do_gettimeofday(&now);
        before = &tx->sdu_stamp;

        diff = (now.tv_sec - before->tv_sec) * 1000000 +
            (now.tv_usec - before->tv_usec);
        if (diff >= 0 && diff < TX_INTERVAL) {
            schedule_work(&sdev->ws);
            spin_unlock_irqrestore(&tx->lock, flags);
            return;
        }
        is_sdu = 1;
    }

    if (!is_sdu && t == NULL) {
        spin_unlock_irqrestore(&tx->lock, flags);
        return;
    }

    tx->can_send = 0;

    spin_unlock_irqrestore(&tx->lock, flags);

    if (is_sdu)
        send_sdu(func, tx);
    else
        send_hci(func, tx, t);
}

static int gdm_sdio_send(void *priv_dev, void *data, int len,
            void (*cb)(void *data), void *cb_data)
{
    struct sdiowm_dev *sdev = priv_dev;
    struct tx_cxt *tx = &sdev->tx;
    struct sdio_tx *t;
    u8 *pkt = data;
    int no_spc = 0;
    u16 cmd_evt;
    unsigned long flags;

    BUG_ON(len > TX_BUF_SIZE - TYPE_A_HEADER_SIZE);

    spin_lock_irqsave(&tx->lock, flags);

    cmd_evt = (pkt[0] << 8) | pkt[1];
    if (cmd_evt == WIMAX_TX_SDU) {
        t = get_tx_struct(tx, &no_spc);
        if (t == NULL) {
            /* This case must not happen. */
            spin_unlock_irqrestore(&tx->lock, flags);
            return -ENOSPC;
        }
        list_add_tail(&t->list, &tx->sdu_list);

        memcpy(t->buf, data, len);

        t->len = len;
        t->callback = cb;
        t->cb_data = cb_data;
    } else {
        t = alloc_tx_struct(tx);
        if (t == NULL) {
            spin_unlock_irqrestore(&tx->lock, flags);
            return -ENOMEM;
        }
        list_add_tail(&t->list, &tx->hci_list);

        t->buf[0] = len & 0xff;
        t->buf[1] = (len >> 8) & 0xff;
        t->buf[2] = (len >> 16) & 0xff;
        t->buf[3] = 2;
        memcpy(t->buf + TYPE_A_HEADER_SIZE, data, len);

        t->len = len + TYPE_A_HEADER_SIZE;
        t->callback = cb;
        t->cb_data = cb_data;
    }

    if (tx->can_send)
        schedule_work(&sdev->ws);

    spin_unlock_irqrestore(&tx->lock, flags);

    if (no_spc)
        return -ENOSPC;

    return 0;
}

/*
 * Handle the HCI, WIMAX_SDU_TX_FLOW.
 */
static int control_sdu_tx_flow(struct sdiowm_dev *sdev, u8 *hci_data, int len)
{
    struct tx_cxt *tx = &sdev->tx;
    u16 cmd_evt;
    unsigned long flags;

    spin_lock_irqsave(&tx->lock, flags);

    cmd_evt = (hci_data[0] << 8) | (hci_data[1]);
    if (cmd_evt != WIMAX_SDU_TX_FLOW)
        goto out;

    if (hci_data[4] == 0) {
#ifdef DEBUG
        printk(KERN_DEBUG "WIMAX ==> STOP SDU TX\n");
#endif
        tx->stop_sdu_tx = 1;
    } else if (hci_data[4] == 1) {
#ifdef DEBUG
        printk(KERN_DEBUG "WIMAX ==> START SDU TX\n");
#endif
        tx->stop_sdu_tx = 0;
        if (tx->can_send)
            schedule_work(&sdev->ws);
        /*
         * If free buffer for sdu tx doesn't exist, then tx queue
         * should not be woken. For this reason, don't pass the command,
         * START_SDU_TX.
         */
        if (list_empty(&tx->free_list))
            len = 0;
    }

out:
    spin_unlock_irqrestore(&tx->lock, flags);
    return len;
}

static void gdm_sdio_irq(struct sdio_func *func)
{
    struct phy_dev *phy_dev = sdio_get_drvdata(func);
    struct sdiowm_dev *sdev = phy_dev->priv_dev;
    struct tx_cxt *tx = &sdev->tx;
    struct rx_cxt *rx = &sdev->rx;
    struct sdio_rx *r;
    unsigned long flags;
    u8 val, hdr[TYPE_A_LOOKAHEAD_SIZE], *buf;
    u32 len, blocks, n;
    int ret, remain;

    /* Check interrupt */
    val = sdio_readb(func, 0x13, &ret);
    if (val & 0x01)
        sdio_writeb(func, 0x01, 0x13, &ret);    /* clear interrupt */
    else
        return;

    ret = sdio_memcpy_fromio(func, hdr, 0x0, TYPE_A_LOOKAHEAD_SIZE);
    if (ret) {
        printk(KERN_ERR "Cannot read from function %d\n", func->num);
        goto done;
    }

    len = (hdr[2] << 16) | (hdr[1] << 8) | hdr[0];
    if (len > (RX_BUF_SIZE - TYPE_A_HEADER_SIZE)) {
        printk(KERN_ERR "Too big Type-A size: %d\n", len);
        goto done;
    }

    if (hdr[3] == 1) {  /* Ack */
#ifdef DEBUG
        u32 *ack_seq = (u32 *)&hdr[4];
#endif
        spin_lock_irqsave(&tx->lock, flags);
        tx->can_send = 1;

        if (!list_empty(&tx->sdu_list) || !list_empty(&tx->hci_list))
            schedule_work(&sdev->ws);
        spin_unlock_irqrestore(&tx->lock, flags);
#ifdef DEBUG
        printk(KERN_DEBUG "Ack... %0x\n", ntohl(*ack_seq));
#endif
        goto done;
    }

    memcpy(rx->rx_buf, hdr + TYPE_A_HEADER_SIZE,
            TYPE_A_LOOKAHEAD_SIZE - TYPE_A_HEADER_SIZE);

    buf = rx->rx_buf + TYPE_A_LOOKAHEAD_SIZE - TYPE_A_HEADER_SIZE;
    remain = len - TYPE_A_LOOKAHEAD_SIZE + TYPE_A_HEADER_SIZE;
    if (remain <= 0)
        goto end_io;

    blocks = remain / func->cur_blksize;

    if (blocks) {
        n = blocks * func->cur_blksize;
        ret = sdio_memcpy_fromio(func, buf, 0x0, n);
        if (ret) {
            printk(KERN_ERR "Cannot read from function %d\n",
                func->num);
            goto done;
        }
        buf += n;
        remain -= n;
    }

    if (remain) {
        ret = sdio_memcpy_fromio(func, buf, 0x0, remain);
        if (ret) {
            printk(KERN_ERR "Cannot read from function %d\n",
                func->num);
            goto done;
        }
    }

end_io:
#ifdef DEBUG
    hexdump("sdio_receive", rx->rx_buf, len);
#endif
    len = control_sdu_tx_flow(sdev, rx->rx_buf, len);

    spin_lock_irqsave(&rx->lock, flags);

    if (!list_empty(&rx->req_list)) {
        r = list_entry(rx->req_list.next, struct sdio_rx, list);
        spin_unlock_irqrestore(&rx->lock, flags);
        if (r->callback)
            r->callback(r->cb_data, rx->rx_buf, len);
        spin_lock_irqsave(&rx->lock, flags);
        list_del(&r->list);
        put_rx_struct(rx, r);
    }

    spin_unlock_irqrestore(&rx->lock, flags);

done:
    sdio_writeb(func, 0x00, 0x10, &ret);    /* PCRRT */
    if (!phy_dev->netdev)
        register_wimax_device(phy_dev, &func->dev);
}

static int gdm_sdio_receive(void *priv_dev,
                void (*cb)(void *cb_data, void *data, int len),
                void *cb_data)
{
    struct sdiowm_dev *sdev = priv_dev;
    struct rx_cxt *rx = &sdev->rx;
    struct sdio_rx *r;
    unsigned long flags;

    spin_lock_irqsave(&rx->lock, flags);
    r = get_rx_struct(rx);
    if (r == NULL) {
        spin_unlock_irqrestore(&rx->lock, flags);
        return -ENOMEM;
    }

    r->callback = cb;
    r->cb_data = cb_data;

    list_add_tail(&r->list, &rx->req_list);
    spin_unlock_irqrestore(&rx->lock, flags);

    return 0;
}

static int sdio_wimax_probe(struct sdio_func *func,
                const struct sdio_device_id *id)
{
    int ret;
    struct phy_dev *phy_dev = NULL;
    struct sdiowm_dev *sdev = NULL;

    printk(KERN_INFO "Found GDM SDIO VID = 0x%04x PID = 0x%04x...\n",
            func->vendor, func->device);
    printk(KERN_INFO "GCT WiMax driver version %s\n", DRIVER_VERSION);

    sdio_claim_host(func);
    sdio_enable_func(func);
    sdio_claim_irq(func, gdm_sdio_irq);

    ret = sdio_boot(func);
    if (ret)
        return ret;

    phy_dev = kzalloc(sizeof(*phy_dev), GFP_KERNEL);
    if (phy_dev == NULL) {
        ret = -ENOMEM;
        goto out;
    }
    sdev = kzalloc(sizeof(*sdev), GFP_KERNEL);
    if (sdev == NULL) {
        ret = -ENOMEM;
        goto out;
    }

    phy_dev->priv_dev = (void *)sdev;
    phy_dev->send_func = gdm_sdio_send;
    phy_dev->rcv_func = gdm_sdio_receive;

    ret = init_sdio(sdev);
    if (ret < 0)
        goto out;

    sdev->func = func;

    sdio_writeb(func, 1, 0x14, &ret);   /* Enable interrupt */
    sdio_release_host(func);

    INIT_WORK(&sdev->ws, do_tx);

    sdio_set_drvdata(func, phy_dev);
out:
    if (ret) {
        kfree(phy_dev);
        kfree(sdev);
    }

    return ret;
}

static void sdio_wimax_remove(struct sdio_func *func)
{
    struct phy_dev *phy_dev = sdio_get_drvdata(func);
    struct sdiowm_dev *sdev = phy_dev->priv_dev;

    if (phy_dev->netdev)
        unregister_wimax_device(phy_dev);
    sdio_claim_host(func);
    sdio_release_irq(func);
    sdio_disable_func(func);
    sdio_release_host(func);
    release_sdio(sdev);

    kfree(sdev);
    kfree(phy_dev);
}

static const struct sdio_device_id sdio_wimax_ids[] = {
    { SDIO_DEVICE(0x0296, 0x5347) },
    {0}
};

MODULE_DEVICE_TABLE(sdio, sdio_wimax_ids);

static struct sdio_driver sdio_wimax_driver = {
    .probe      = sdio_wimax_probe,
    .remove     = sdio_wimax_remove,
    .name       = "sdio_wimax",
    .id_table   = sdio_wimax_ids,
};

static int __init sdio_gdm_wimax_init(void)
{
    return sdio_register_driver(&sdio_wimax_driver);
}

static void __exit sdio_gdm_wimax_exit(void)
{
    sdio_unregister_driver(&sdio_wimax_driver);
}

module_init(sdio_gdm_wimax_init);
module_exit(sdio_gdm_wimax_exit);

MODULE_VERSION(DRIVER_VERSION);
MODULE_DESCRIPTION("GCT WiMax SDIO Device Driver");
MODULE_AUTHOR("Ethan Park");
MODULE_LICENSE("GPL");