LXR linux/drivers/uwb/scan.c

   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 "uwb-internal.h"
  39
  40
  41/**
  42 * Start/stop scanning in a radio controller
  43 *
  44 * @rc:      UWB Radio Controlller
  45 * @channel: Channel to scan; encodings in WUSB1.0[Table 5.12]
  46 * @type:    Type of scanning to do.
  47 * @bpst_offset: value at which to start scanning (if type ==
  48 *                UWB_SCAN_ONLY_STARTTIME)
  49 * @returns: 0 if ok, < 0 errno code on error
  50 *
  51 * We put the command on kmalloc'ed memory as some arches cannot do
  52 * USB from the stack. The reply event is copied from an stage buffer,
  53 * so it can be in the stack. See WUSB1.0[8.6.2.4] for more details.
  54 */
  55int uwb_rc_scan(struct uwb_rc *rc,
  56                unsigned channel, enum uwb_scan_type type,
  57                unsigned bpst_offset)
  58{
  59        int result;
  60        struct uwb_rc_cmd_scan *cmd;
  61        struct uwb_rc_evt_confirm reply;
  62
  63        result = -ENOMEM;
  64        cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
  65        if (cmd == NULL)
  66                goto error_kzalloc;
  67        mutex_lock(&rc->uwb_dev.mutex);
  68        cmd->rccb.bCommandType = UWB_RC_CET_GENERAL;
  69        cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SCAN);
  70        cmd->bChannelNumber = channel;
  71        cmd->bScanState = type;
  72        cmd->wStartTime = cpu_to_le16(bpst_offset);
  73        reply.rceb.bEventType = UWB_RC_CET_GENERAL;
  74        reply.rceb.wEvent = UWB_RC_CMD_SCAN;
  75        result = uwb_rc_cmd(rc, "SCAN", &cmd->rccb, sizeof(*cmd),
  76                            &reply.rceb, sizeof(reply));
  77        if (result < 0)
  78                goto error_cmd;
  79        if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
  80                dev_err(&rc->uwb_dev.dev,
  81                        "SCAN: command execution failed: %s (%d)\n",
  82                        uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
  83                result = -EIO;
  84                goto error_cmd;
  85        }
  86        rc->scanning = channel;
  87        rc->scan_type = type;
  88error_cmd:
  89        mutex_unlock(&rc->uwb_dev.mutex);
  90        kfree(cmd);
  91error_kzalloc:
  92        return result;
  93}
  94
  95/*
  96 * Print scanning state
  97 */
  98static ssize_t uwb_rc_scan_show(struct device *dev,
  99                                struct device_attribute *attr, char *buf)
 100{
 101        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 102        struct uwb_rc *rc = uwb_dev->rc;
 103        ssize_t result;
 104
 105        mutex_lock(&rc->uwb_dev.mutex);
 106        result = sprintf(buf, "%d %d\n", rc->scanning, rc->scan_type);
 107        mutex_unlock(&rc->uwb_dev.mutex);
 108        return result;
 109}
 110
 111/*
 112 *
 113 */
 114static ssize_t uwb_rc_scan_store(struct device *dev,
 115                                 struct device_attribute *attr,
 116                                 const char *buf, size_t size)
 117{
 118        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 119        struct uwb_rc *rc = uwb_dev->rc;
 120        unsigned channel;
 121        unsigned type;
 122        unsigned bpst_offset = 0;
 123        ssize_t result = -EINVAL;
 124
 125        result = sscanf(buf, "%u %u %u\n", &channel, &type, &bpst_offset);
 126        if (result >= 2 && type < UWB_SCAN_TOP)
 127                result = uwb_rc_scan(rc, channel, type, bpst_offset);
 128
 129        return result < 0 ? result : size;
 130}
 131
 132/** Radio Control sysfs interface (declaration) */
 133DEVICE_ATTR(scan, S_IRUGO | S_IWUSR, uwb_rc_scan_show, uwb_rc_scan_store);
 134