reset.c

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/*
 * Ultra Wide Band
 * UWB basic command support and radio reset
 *
 * Copyright (C) 2005-2006 Intel Corporation
 * Inaky Perez-Gonzalez <[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.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 *
 * FIXME:
 *
 *  - docs
 *
 *  - Now we are serializing (using the uwb_dev->mutex) the command
 *    execution; it should be parallelized as much as possible some
 *    day.
 */
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/export.h>

#include "uwb-internal.h"

static
const char *__strerror[] = {
    "success",
    "failure",
    "hardware failure",
    "no more slots",
    "beacon is too large",
    "invalid parameter",
    "unsupported power level",
    "time out (wa) or invalid ie data (whci)",
    "beacon size exceeded",
    "cancelled",
    "invalid state",
    "invalid size",
    "ack not received",
    "no more asie notification",
};


const char *uwb_rc_strerror(unsigned code)
{
    if (code == 255)
        return "time out";
    if (code >= ARRAY_SIZE(__strerror))
        return "unknown error";
    return __strerror[code];
}

int uwb_rc_cmd_async(struct uwb_rc *rc, const char *cmd_name,
             struct uwb_rccb *cmd, size_t cmd_size,
             u8 expected_type, u16 expected_event,
             uwb_rc_cmd_cb_f cb, void *arg)
{
    struct device *dev = &rc->uwb_dev.dev;
    struct uwb_rc_neh *neh;
    int needtofree = 0;
    int result;

    uwb_dev_lock(&rc->uwb_dev); /* Protect against rc->priv being removed */
    if (rc->priv == NULL) {
        uwb_dev_unlock(&rc->uwb_dev);
        return -ESHUTDOWN;
    }

    if (rc->filter_cmd) {
        needtofree = rc->filter_cmd(rc, &cmd, &cmd_size);
        if (needtofree < 0 && needtofree != -ENOANO) {
            dev_err(dev, "%s: filter error: %d\n",
                cmd_name, needtofree);
            uwb_dev_unlock(&rc->uwb_dev);
            return needtofree;
        }
    }

    neh = uwb_rc_neh_add(rc, cmd, expected_type, expected_event, cb, arg);
    if (IS_ERR(neh)) {
        result = PTR_ERR(neh);
        goto out;
    }

    result = rc->cmd(rc, cmd, cmd_size);
    uwb_dev_unlock(&rc->uwb_dev);
    if (result < 0)
        uwb_rc_neh_rm(rc, neh);
    else
        uwb_rc_neh_arm(rc, neh);
    uwb_rc_neh_put(neh);
out:
    if (needtofree == 1)
        kfree(cmd);
    return result < 0 ? result : 0;
}
EXPORT_SYMBOL_GPL(uwb_rc_cmd_async);

struct uwb_rc_cmd_done_params {
    struct completion completion;
    struct uwb_rceb *reply;
    ssize_t reply_size;
};

static void uwb_rc_cmd_done(struct uwb_rc *rc, void *arg,
                struct uwb_rceb *reply, ssize_t reply_size)
{
    struct uwb_rc_cmd_done_params *p = (struct uwb_rc_cmd_done_params *)arg;

    if (reply_size > 0) {
        if (p->reply)
            reply_size = min(p->reply_size, reply_size);
        else
            p->reply = kmalloc(reply_size, GFP_ATOMIC);

        if (p->reply)
            memcpy(p->reply, reply, reply_size);
        else
            reply_size = -ENOMEM;
    }
    p->reply_size = reply_size;
    complete(&p->completion);
}


static
ssize_t __uwb_rc_cmd(struct uwb_rc *rc, const char *cmd_name,
             struct uwb_rccb *cmd, size_t cmd_size,
             struct uwb_rceb *reply, size_t reply_size,
             u8 expected_type, u16 expected_event,
             struct uwb_rceb **preply)
{
    ssize_t result = 0;
    struct device *dev = &rc->uwb_dev.dev;
    struct uwb_rc_cmd_done_params params;

    init_completion(&params.completion);
    params.reply = reply;
    params.reply_size = reply_size;

    result = uwb_rc_cmd_async(rc, cmd_name, cmd, cmd_size,
                  expected_type, expected_event,
                  uwb_rc_cmd_done, &params);
    if (result)
        return result;

    wait_for_completion(&params.completion);

    if (preply)
        *preply = params.reply;

    if (params.reply_size < 0)
        dev_err(dev, "%s: confirmation event 0x%02x/%04x/%02x "
            "reception failed: %d\n", cmd_name,
            expected_type, expected_event, cmd->bCommandContext,
            (int)params.reply_size);
    return params.reply_size;
}


ssize_t uwb_rc_cmd(struct uwb_rc *rc, const char *cmd_name,
           struct uwb_rccb *cmd, size_t cmd_size,
           struct uwb_rceb *reply, size_t reply_size)
{
    struct device *dev = &rc->uwb_dev.dev;
    ssize_t result;

    result = __uwb_rc_cmd(rc, cmd_name,
                  cmd, cmd_size, reply, reply_size,
                  reply->bEventType, reply->wEvent, NULL);

    if (result > 0 && result < reply_size) {
        dev_err(dev, "%s: not enough data returned for decoding reply "
            "(%zu bytes received vs at least %zu needed)\n",
            cmd_name, result, reply_size);
        result = -EIO;
    }
    return result;
}
EXPORT_SYMBOL_GPL(uwb_rc_cmd);


ssize_t uwb_rc_vcmd(struct uwb_rc *rc, const char *cmd_name,
            struct uwb_rccb *cmd, size_t cmd_size,
            u8 expected_type, u16 expected_event,
            struct uwb_rceb **preply)
{
    return __uwb_rc_cmd(rc, cmd_name, cmd, cmd_size, NULL, 0,
                expected_type, expected_event, preply);
}
EXPORT_SYMBOL_GPL(uwb_rc_vcmd);


int uwb_rc_reset(struct uwb_rc *rc)
{
    int result = -ENOMEM;
    struct uwb_rc_evt_confirm reply;
    struct uwb_rccb *cmd;
    size_t cmd_size = sizeof(*cmd);

    mutex_lock(&rc->uwb_dev.mutex);
    cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
    if (cmd == NULL)
        goto error_kzalloc;
    cmd->bCommandType = UWB_RC_CET_GENERAL;
    cmd->wCommand = cpu_to_le16(UWB_RC_CMD_RESET);
    reply.rceb.bEventType = UWB_RC_CET_GENERAL;
    reply.rceb.wEvent = UWB_RC_CMD_RESET;
    result = uwb_rc_cmd(rc, "RESET", cmd, cmd_size,
                &reply.rceb, sizeof(reply));
    if (result < 0)
        goto error_cmd;
    if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
        dev_err(&rc->uwb_dev.dev,
            "RESET: command execution failed: %s (%d)\n",
            uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
        result = -EIO;
    }
error_cmd:
    kfree(cmd);
error_kzalloc:
    mutex_unlock(&rc->uwb_dev.mutex);
    return result;
}

int uwbd_msg_handle_reset(struct uwb_event *evt)
{
    struct uwb_rc *rc = evt->rc;
    int ret;

    dev_info(&rc->uwb_dev.dev, "resetting radio controller\n");
    ret = rc->reset(rc);
    if (ret < 0) {
        dev_err(&rc->uwb_dev.dev, "failed to reset hardware: %d\n", ret);
        goto error;
    }
    return 0;
error:
    /* Nothing can be done except try the reset again. Wait a bit
       to avoid reset loops during probe() or remove(). */
    msleep(1000);
    uwb_rc_reset_all(rc);
    return ret;
}

void uwb_rc_reset_all(struct uwb_rc *rc)
{
    struct uwb_event *evt;

    evt = kzalloc(sizeof(struct uwb_event), GFP_ATOMIC);
    if (unlikely(evt == NULL))
        return;

    evt->rc = __uwb_rc_get(rc); /* will be put by uwbd's uwbd_event_handle() */
    evt->ts_jiffies = jiffies;
    evt->type = UWB_EVT_TYPE_MSG;
    evt->message = UWB_EVT_MSG_RESET;

    uwbd_event_queue(evt);
}
EXPORT_SYMBOL_GPL(uwb_rc_reset_all);

void uwb_rc_pre_reset(struct uwb_rc *rc)
{
    rc->stop(rc);
    uwbd_flush(rc);

    uwb_radio_reset_state(rc);
    uwb_rsv_remove_all(rc);
}
EXPORT_SYMBOL_GPL(uwb_rc_pre_reset);

int uwb_rc_post_reset(struct uwb_rc *rc)
{
    int ret;

    ret = rc->start(rc);
    if (ret)
        goto out;
    ret = uwb_rc_mac_addr_set(rc, &rc->uwb_dev.mac_addr);
    if (ret)
        goto out;
    ret = uwb_rc_dev_addr_set(rc, &rc->uwb_dev.dev_addr);
    if (ret)
        goto out;
out:
    return ret;
}
EXPORT_SYMBOL_GPL(uwb_rc_post_reset);