linux/drivers/uwb/scan.c
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   1/*
   2 * Ultra Wide Band
   3 * Scanning management
   4 *
   5 * Copyright (C) 2005-2006 Intel Corporation
   6 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License version
  10 * 2 as published by the Free Software Foundation.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20 * 02110-1301, USA.
  21 *
  22 *
  23 *
  24 * FIXME: docs
  25 * FIXME: there are issues here on how BEACON and SCAN on USB RCI deal
  26 *        with each other. Currently seems that START_BEACON while
  27 *        SCAN_ONLY will cancel the scan, so we need to update the
  28 *        state here. Clarification request sent by email on
  29 *        10/05/2005.
  30 *        10/28/2005 No clear answer heard--maybe we'll hack the API
  31 *                   so that when we start beaconing, if the HC is
  32 *                   scanning in a mode not compatible with beaconing
  33 *                   we just fail.
  34 */
  35
  36#include <linux/device.h>
  37#include <linux/err.h>
  38#include <linux/slab.h>
  39#include <linux/stat.h>
  40#include "uwb-internal.h"
  41
  42
  43/**
  44 * Start/stop scanning in a radio controller
  45 *
  46 * @rc:      UWB Radio Controller
  47 * @channel: Channel to scan; encodings in WUSB1.0[Table 5.12]
  48 * @type:    Type of scanning to do.
  49 * @bpst_offset: value at which to start scanning (if type ==
  50 *                UWB_SCAN_ONLY_STARTTIME)
  51 * @returns: 0 if ok, < 0 errno code on error
  52 *
  53 * We put the command on kmalloc'ed memory as some arches cannot do
  54 * USB from the stack. The reply event is copied from an stage buffer,
  55 * so it can be in the stack. See WUSB1.0[8.6.2.4] for more details.
  56 */
  57int uwb_rc_scan(struct uwb_rc *rc,
  58                unsigned channel, enum uwb_scan_type type,
  59                unsigned bpst_offset)
  60{
  61        int result;
  62        struct uwb_rc_cmd_scan *cmd;
  63        struct uwb_rc_evt_confirm reply;
  64
  65        result = -ENOMEM;
  66        cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
  67        if (cmd == NULL)
  68                goto error_kzalloc;
  69        mutex_lock(&rc->uwb_dev.mutex);
  70        cmd->rccb.bCommandType = UWB_RC_CET_GENERAL;
  71        cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SCAN);
  72        cmd->bChannelNumber = channel;
  73        cmd->bScanState = type;
  74        cmd->wStartTime = cpu_to_le16(bpst_offset);
  75        reply.rceb.bEventType = UWB_RC_CET_GENERAL;
  76        reply.rceb.wEvent = UWB_RC_CMD_SCAN;
  77        result = uwb_rc_cmd(rc, "SCAN", &cmd->rccb, sizeof(*cmd),
  78                            &reply.rceb, sizeof(reply));
  79        if (result < 0)
  80                goto error_cmd;
  81        if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
  82                dev_err(&rc->uwb_dev.dev,
  83                        "SCAN: command execution failed: %s (%d)\n",
  84                        uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
  85                result = -EIO;
  86                goto error_cmd;
  87        }
  88        rc->scanning = channel;
  89        rc->scan_type = type;
  90error_cmd:
  91        mutex_unlock(&rc->uwb_dev.mutex);
  92        kfree(cmd);
  93error_kzalloc:
  94        return result;
  95}
  96
  97/*
  98 * Print scanning state
  99 */
 100static ssize_t uwb_rc_scan_show(struct device *dev,
 101                                struct device_attribute *attr, char *buf)
 102{
 103        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 104        struct uwb_rc *rc = uwb_dev->rc;
 105        ssize_t result;
 106
 107        mutex_lock(&rc->uwb_dev.mutex);
 108        result = sprintf(buf, "%d %d\n", rc->scanning, rc->scan_type);
 109        mutex_unlock(&rc->uwb_dev.mutex);
 110        return result;
 111}
 112
 113/*
 114 *
 115 */
 116static ssize_t uwb_rc_scan_store(struct device *dev,
 117                                 struct device_attribute *attr,
 118                                 const char *buf, size_t size)
 119{
 120        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 121        struct uwb_rc *rc = uwb_dev->rc;
 122        unsigned channel;
 123        unsigned type;
 124        unsigned bpst_offset = 0;
 125        ssize_t result = -EINVAL;
 126
 127        result = sscanf(buf, "%u %u %u\n", &channel, &type, &bpst_offset);
 128        if (result >= 2 && type < UWB_SCAN_TOP)
 129                result = uwb_rc_scan(rc, channel, type, bpst_offset);
 130
 131        return result < 0 ? result : size;
 132}
 133
 134/** Radio Control sysfs interface (declaration) */
 135DEVICE_ATTR(scan, S_IRUGO | S_IWUSR, uwb_rc_scan_show, uwb_rc_scan_store);
 136
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