nfcwilink.c

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/*
 *  Texas Instrument's NFC Driver For Shared Transport.
 *
 *  NFC Driver acts as interface between NCI core and
 *  TI Shared Transport Layer.
 *
 *  Copyright (C) 2011 Texas Instruments, Inc.
 *
 *  Written by Ilan Elias <[email protected]>
 *
 *  Acknowledgements:
 *  This file is based on btwilink.c, which was written
 *  by Raja Mani and Pavan Savoy.
 *
 *  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.
 *
 *  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/platform_device.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/firmware.h>
#include <linux/nfc.h>
#include <net/nfc/nci.h>
#include <net/nfc/nci_core.h>
#include <linux/ti_wilink_st.h>

#define NFCWILINK_CHNL          12
#define NFCWILINK_OPCODE        7
#define NFCWILINK_MAX_FRAME_SIZE    300
#define NFCWILINK_HDR_LEN       4
#define NFCWILINK_OFFSET_LEN_IN_HDR 1
#define NFCWILINK_LEN_SIZE      2
#define NFCWILINK_REGISTER_TIMEOUT  8000    /* 8 sec */
#define NFCWILINK_CMD_TIMEOUT       5000    /* 5 sec */

#define BTS_FILE_NAME_MAX_SIZE      40
#define BTS_FILE_HDR_MAGIC      0x42535442
#define BTS_FILE_CMD_MAX_LEN        0xff
#define BTS_FILE_ACTION_TYPE_SEND_CMD   1

#define NCI_VS_NFCC_INFO_CMD_GID    0x2f
#define NCI_VS_NFCC_INFO_CMD_OID    0x12
#define NCI_VS_NFCC_INFO_RSP_GID    0x4f
#define NCI_VS_NFCC_INFO_RSP_OID    0x12

struct nfcwilink_hdr {
    __u8 chnl;
    __u8 opcode;
    __le16 len;
} __packed;

struct nci_vs_nfcc_info_cmd {
    __u8 gid;
    __u8 oid;
    __u8 plen;
} __packed;

struct nci_vs_nfcc_info_rsp {
    __u8 gid;
    __u8 oid;
    __u8 plen;
    __u8 status;
    __u8 hw_id;
    __u8 sw_ver_x;
    __u8 sw_ver_z;
    __u8 patch_id;
} __packed;

struct bts_file_hdr {
    __le32 magic;
    __le32 ver;
    __u8 rfu[24];
    __u8 actions[0];
} __packed;

struct bts_file_action {
    __le16 type;
    __le16 len;
    __u8 data[0];
} __packed;

struct nfcwilink {
    struct platform_device      *pdev;
    struct nci_dev          *ndev;
    unsigned long           flags;

    char                st_register_cb_status;
    long                (*st_write) (struct sk_buff *);

    struct completion       completed;

    struct nci_vs_nfcc_info_rsp nfcc_info;
};

/* NFCWILINK driver flags */
enum {
    NFCWILINK_RUNNING,
    NFCWILINK_FW_DOWNLOAD,
};

static int nfcwilink_send(struct sk_buff *skb);

static inline struct sk_buff *nfcwilink_skb_alloc(unsigned int len, gfp_t how)
{
    struct sk_buff *skb;

    skb = alloc_skb(len + NFCWILINK_HDR_LEN, how);
    if (skb)
        skb_reserve(skb, NFCWILINK_HDR_LEN);

    return skb;
}

static void nfcwilink_fw_download_receive(struct nfcwilink *drv,
                        struct sk_buff *skb)
{
    struct nci_vs_nfcc_info_rsp *rsp = (void *)skb->data;

    /* Detect NCI_VS_NFCC_INFO_RSP and store the result */
    if ((skb->len > 3) && (rsp->gid == NCI_VS_NFCC_INFO_RSP_GID) &&
        (rsp->oid == NCI_VS_NFCC_INFO_RSP_OID)) {
        memcpy(&drv->nfcc_info, rsp,
            sizeof(struct nci_vs_nfcc_info_rsp));
    }

    kfree_skb(skb);

    complete(&drv->completed);
}

static int nfcwilink_get_bts_file_name(struct nfcwilink *drv, char *file_name)
{
    struct nci_vs_nfcc_info_cmd *cmd;
    struct sk_buff *skb;
    unsigned long comp_ret;
    int rc;

    nfc_dev_dbg(&drv->pdev->dev, "get_bts_file_name entry");

    skb = nfcwilink_skb_alloc(sizeof(struct nci_vs_nfcc_info_cmd),
                    GFP_KERNEL);
    if (!skb) {
        nfc_dev_err(&drv->pdev->dev,
                "no memory for nci_vs_nfcc_info_cmd");
        return -ENOMEM;
    }

    skb->dev = (void *)drv->ndev;

    cmd = (struct nci_vs_nfcc_info_cmd *)
            skb_put(skb, sizeof(struct nci_vs_nfcc_info_cmd));
    cmd->gid = NCI_VS_NFCC_INFO_CMD_GID;
    cmd->oid = NCI_VS_NFCC_INFO_CMD_OID;
    cmd->plen = 0;

    drv->nfcc_info.plen = 0;

    rc = nfcwilink_send(skb);
    if (rc)
        return rc;

    comp_ret = wait_for_completion_timeout(&drv->completed,
                msecs_to_jiffies(NFCWILINK_CMD_TIMEOUT));
    nfc_dev_dbg(&drv->pdev->dev, "wait_for_completion_timeout returned %ld",
            comp_ret);
    if (comp_ret == 0) {
        nfc_dev_err(&drv->pdev->dev,
                "timeout on wait_for_completion_timeout");
        return -ETIMEDOUT;
    }

    nfc_dev_dbg(&drv->pdev->dev, "nci_vs_nfcc_info_rsp: plen %d, status %d",
            drv->nfcc_info.plen,
            drv->nfcc_info.status);

    if ((drv->nfcc_info.plen != 5) || (drv->nfcc_info.status != 0)) {
        nfc_dev_err(&drv->pdev->dev,
                "invalid nci_vs_nfcc_info_rsp");
        return -EINVAL;
    }

    snprintf(file_name, BTS_FILE_NAME_MAX_SIZE,
            "TINfcInit_%d.%d.%d.%d.bts",
            drv->nfcc_info.hw_id,
            drv->nfcc_info.sw_ver_x,
            drv->nfcc_info.sw_ver_z,
            drv->nfcc_info.patch_id);

    nfc_dev_info(&drv->pdev->dev, "nfcwilink FW file name: %s", file_name);

    return 0;
}

static int nfcwilink_send_bts_cmd(struct nfcwilink *drv, __u8 *data, int len)
{
    struct nfcwilink_hdr *hdr = (struct nfcwilink_hdr *)data;
    struct sk_buff *skb;
    unsigned long comp_ret;
    int rc;

    nfc_dev_dbg(&drv->pdev->dev, "send_bts_cmd entry");

    /* verify valid cmd for the NFC channel */
    if ((len <= sizeof(struct nfcwilink_hdr)) ||
        (len > BTS_FILE_CMD_MAX_LEN) ||
        (hdr->chnl != NFCWILINK_CHNL) ||
        (hdr->opcode != NFCWILINK_OPCODE)) {
        nfc_dev_err(&drv->pdev->dev,
            "ignoring invalid bts cmd, len %d, chnl %d, opcode %d",
            len, hdr->chnl, hdr->opcode);
        return 0;
    }

    /* remove the ST header */
    len -= sizeof(struct nfcwilink_hdr);
    data += sizeof(struct nfcwilink_hdr);

    skb = nfcwilink_skb_alloc(len, GFP_KERNEL);
    if (!skb) {
        nfc_dev_err(&drv->pdev->dev, "no memory for bts cmd");
        return -ENOMEM;
    }

    skb->dev = (void *)drv->ndev;

    memcpy(skb_put(skb, len), data, len);

    rc = nfcwilink_send(skb);
    if (rc)
        return rc;

    comp_ret = wait_for_completion_timeout(&drv->completed,
                msecs_to_jiffies(NFCWILINK_CMD_TIMEOUT));
    nfc_dev_dbg(&drv->pdev->dev, "wait_for_completion_timeout returned %ld",
            comp_ret);
    if (comp_ret == 0) {
        nfc_dev_err(&drv->pdev->dev,
                "timeout on wait_for_completion_timeout");
        return -ETIMEDOUT;
    }

    return 0;
}

static int nfcwilink_download_fw(struct nfcwilink *drv)
{
    unsigned char file_name[BTS_FILE_NAME_MAX_SIZE];
    const struct firmware *fw;
    __u16 action_type, action_len;
    __u8 *ptr;
    int len, rc;

    nfc_dev_dbg(&drv->pdev->dev, "download_fw entry");

    set_bit(NFCWILINK_FW_DOWNLOAD, &drv->flags);

    rc = nfcwilink_get_bts_file_name(drv, file_name);
    if (rc)
        goto exit;

    rc = request_firmware(&fw, file_name, &drv->pdev->dev);
    if (rc) {
        nfc_dev_err(&drv->pdev->dev, "request_firmware failed %d", rc);

        /* if the file is not found, don't exit with failure */
        if (rc == -ENOENT)
            rc = 0;

        goto exit;
    }

    len = fw->size;
    ptr = (__u8 *)fw->data;

    if ((len == 0) || (ptr == NULL)) {
        nfc_dev_dbg(&drv->pdev->dev,
                "request_firmware returned size %d", len);
        goto release_fw;
    }

    if (__le32_to_cpu(((struct bts_file_hdr *)ptr)->magic) !=
            BTS_FILE_HDR_MAGIC) {
        nfc_dev_err(&drv->pdev->dev, "wrong bts magic number");
        rc = -EINVAL;
        goto release_fw;
    }

    /* remove the BTS header */
    len -= sizeof(struct bts_file_hdr);
    ptr += sizeof(struct bts_file_hdr);

    while (len > 0) {
        action_type =
            __le16_to_cpu(((struct bts_file_action *)ptr)->type);
        action_len =
            __le16_to_cpu(((struct bts_file_action *)ptr)->len);

        nfc_dev_dbg(&drv->pdev->dev, "bts_file_action type %d, len %d",
                action_type, action_len);

        switch (action_type) {
        case BTS_FILE_ACTION_TYPE_SEND_CMD:
            rc = nfcwilink_send_bts_cmd(drv,
                    ((struct bts_file_action *)ptr)->data,
                    action_len);
            if (rc)
                goto release_fw;
            break;
        }

        /* advance to the next action */
        len -= (sizeof(struct bts_file_action) + action_len);
        ptr += (sizeof(struct bts_file_action) + action_len);
    }

release_fw:
    release_firmware(fw);

exit:
    clear_bit(NFCWILINK_FW_DOWNLOAD, &drv->flags);
    return rc;
}

/* Called by ST when registration is complete */
static void nfcwilink_register_complete(void *priv_data, char data)
{
    struct nfcwilink *drv = priv_data;

    nfc_dev_dbg(&drv->pdev->dev, "register_complete entry");

    /* store ST registration status */
    drv->st_register_cb_status = data;

    /* complete the wait in nfc_st_open() */
    complete(&drv->completed);
}

/* Called by ST when receive data is available */
static long nfcwilink_receive(void *priv_data, struct sk_buff *skb)
{
    struct nfcwilink *drv = priv_data;
    int rc;

    if (!skb)
        return -EFAULT;

    if (!drv) {
        kfree_skb(skb);
        return -EFAULT;
    }

    nfc_dev_dbg(&drv->pdev->dev, "receive entry, len %d", skb->len);

    /* strip the ST header
    (apart for the chnl byte, which is not received in the hdr) */
    skb_pull(skb, (NFCWILINK_HDR_LEN-1));

    if (test_bit(NFCWILINK_FW_DOWNLOAD, &drv->flags)) {
        nfcwilink_fw_download_receive(drv, skb);
        return 0;
    }

    skb->dev = (void *) drv->ndev;

    /* Forward skb to NCI core layer */
    rc = nci_recv_frame(skb);
    if (rc < 0) {
        nfc_dev_err(&drv->pdev->dev, "nci_recv_frame failed %d", rc);
        return rc;
    }

    return 0;
}

/* protocol structure registered with ST */
static struct st_proto_s nfcwilink_proto = {
    .chnl_id = NFCWILINK_CHNL,
    .max_frame_size = NFCWILINK_MAX_FRAME_SIZE,
    .hdr_len = (NFCWILINK_HDR_LEN-1),   /* not including chnl byte */
    .offset_len_in_hdr = NFCWILINK_OFFSET_LEN_IN_HDR,
    .len_size = NFCWILINK_LEN_SIZE,
    .reserve = 0,
    .recv = nfcwilink_receive,
    .reg_complete_cb = nfcwilink_register_complete,
    .write = NULL,
};

static int nfcwilink_open(struct nci_dev *ndev)
{
    struct nfcwilink *drv = nci_get_drvdata(ndev);
    unsigned long comp_ret;
    int rc;

    nfc_dev_dbg(&drv->pdev->dev, "open entry");

    if (test_and_set_bit(NFCWILINK_RUNNING, &drv->flags)) {
        rc = -EBUSY;
        goto exit;
    }

    nfcwilink_proto.priv_data = drv;

    init_completion(&drv->completed);
    drv->st_register_cb_status = -EINPROGRESS;

    rc = st_register(&nfcwilink_proto);
    if (rc < 0) {
        if (rc == -EINPROGRESS) {
            comp_ret = wait_for_completion_timeout(
            &drv->completed,
            msecs_to_jiffies(NFCWILINK_REGISTER_TIMEOUT));

            nfc_dev_dbg(&drv->pdev->dev,
            "wait_for_completion_timeout returned %ld",
            comp_ret);

            if (comp_ret == 0) {
                /* timeout */
                rc = -ETIMEDOUT;
                goto clear_exit;
            } else if (drv->st_register_cb_status != 0) {
                rc = drv->st_register_cb_status;
                nfc_dev_err(&drv->pdev->dev,
                "st_register_cb failed %d", rc);
                goto clear_exit;
            }
        } else {
            nfc_dev_err(&drv->pdev->dev,
                "st_register failed %d", rc);
            goto clear_exit;
        }
    }

    /* st_register MUST fill the write callback */
    BUG_ON(nfcwilink_proto.write == NULL);
    drv->st_write = nfcwilink_proto.write;

    if (nfcwilink_download_fw(drv)) {
        nfc_dev_err(&drv->pdev->dev, "nfcwilink_download_fw failed %d",
                rc);
        /* open should succeed, even if the FW download failed */
    }

    goto exit;

clear_exit:
    clear_bit(NFCWILINK_RUNNING, &drv->flags);

exit:
    return rc;
}

static int nfcwilink_close(struct nci_dev *ndev)
{
    struct nfcwilink *drv = nci_get_drvdata(ndev);
    int rc;

    nfc_dev_dbg(&drv->pdev->dev, "close entry");

    if (!test_and_clear_bit(NFCWILINK_RUNNING, &drv->flags))
        return 0;

    rc = st_unregister(&nfcwilink_proto);
    if (rc)
        nfc_dev_err(&drv->pdev->dev, "st_unregister failed %d", rc);

    drv->st_write = NULL;

    return rc;
}

static int nfcwilink_send(struct sk_buff *skb)
{
    struct nci_dev *ndev = (struct nci_dev *)skb->dev;
    struct nfcwilink *drv = nci_get_drvdata(ndev);
    struct nfcwilink_hdr hdr = {NFCWILINK_CHNL, NFCWILINK_OPCODE, 0x0000};
    long len;

    nfc_dev_dbg(&drv->pdev->dev, "send entry, len %d", skb->len);

    if (!test_bit(NFCWILINK_RUNNING, &drv->flags)) {
        kfree_skb(skb);
        return -EINVAL;
    }

    /* add the ST hdr to the start of the buffer */
    hdr.len = cpu_to_le16(skb->len);
    memcpy(skb_push(skb, NFCWILINK_HDR_LEN), &hdr, NFCWILINK_HDR_LEN);

    /* Insert skb to shared transport layer's transmit queue.
     * Freeing skb memory is taken care in shared transport layer,
     * so don't free skb memory here.
     */
    len = drv->st_write(skb);
    if (len < 0) {
        kfree_skb(skb);
        nfc_dev_err(&drv->pdev->dev, "st_write failed %ld", len);
        return -EFAULT;
    }

    return 0;
}

static struct nci_ops nfcwilink_ops = {
    .open = nfcwilink_open,
    .close = nfcwilink_close,
    .send = nfcwilink_send,
};

static int nfcwilink_probe(struct platform_device *pdev)
{
    static struct nfcwilink *drv;
    int rc;
    __u32 protocols;

    nfc_dev_dbg(&pdev->dev, "probe entry");

    drv = kzalloc(sizeof(struct nfcwilink), GFP_KERNEL);
    if (!drv) {
        rc = -ENOMEM;
        goto exit;
    }

    drv->pdev = pdev;

    protocols = NFC_PROTO_JEWEL_MASK
        | NFC_PROTO_MIFARE_MASK | NFC_PROTO_FELICA_MASK
        | NFC_PROTO_ISO14443_MASK
        | NFC_PROTO_ISO14443_B_MASK
        | NFC_PROTO_NFC_DEP_MASK;

    drv->ndev = nci_allocate_device(&nfcwilink_ops,
                    protocols,
                    NFCWILINK_HDR_LEN,
                    0);
    if (!drv->ndev) {
        nfc_dev_err(&pdev->dev, "nci_allocate_device failed");
        rc = -ENOMEM;
        goto free_exit;
    }

    nci_set_parent_dev(drv->ndev, &pdev->dev);
    nci_set_drvdata(drv->ndev, drv);

    rc = nci_register_device(drv->ndev);
    if (rc < 0) {
        nfc_dev_err(&pdev->dev, "nci_register_device failed %d", rc);
        goto free_dev_exit;
    }

    dev_set_drvdata(&pdev->dev, drv);

    goto exit;

free_dev_exit:
    nci_free_device(drv->ndev);

free_exit:
    kfree(drv);

exit:
    return rc;
}

static int nfcwilink_remove(struct platform_device *pdev)
{
    struct nfcwilink *drv = dev_get_drvdata(&pdev->dev);
    struct nci_dev *ndev;

    nfc_dev_dbg(&pdev->dev, "remove entry");

    if (!drv)
        return -EFAULT;

    ndev = drv->ndev;

    nci_unregister_device(ndev);
    nci_free_device(ndev);

    kfree(drv);

    dev_set_drvdata(&pdev->dev, NULL);

    return 0;
}

static struct platform_driver nfcwilink_driver = {
    .probe = nfcwilink_probe,
    .remove = nfcwilink_remove,
    .driver = {
        .name = "nfcwilink",
        .owner = THIS_MODULE,
    },
};

module_platform_driver(nfcwilink_driver);

/* ------ Module Info ------ */

MODULE_AUTHOR("Ilan Elias <[email protected]>");
MODULE_DESCRIPTION("NFC Driver for TI Shared Transport");
MODULE_LICENSE("GPL");