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 <linux/slab.h>
  39#include "uwb-internal.h"
  40
  41
  42/**
  43 * Start/stop scanning in a radio controller
  44 *
  45 * @rc:      UWB Radio Controlller
  46 * @channel: Channel to scan; encodings in WUSB1.0[Table 5.12]
  47 * @type:    Type of scanning to do.
  48 * @bpst_offset: value at which to start scanning (if type ==
  49 *                UWB_SCAN_ONLY_STARTTIME)
  50 * @returns: 0 if ok, < 0 errno code on error
  51 *
  52 * We put the command on kmalloc'ed memory as some arches cannot do
  53 * USB from the stack. The reply event is copied from an stage buffer,
  54 * so it can be in the stack. See WUSB1.0[8.6.2.4] for more details.
  55 */
  56int uwb_rc_scan(struct uwb_rc *rc,
  57                unsigned channel, enum uwb_scan_type type,
  58                unsigned bpst_offset)
  59{
  60        int result;
  61        struct uwb_rc_cmd_scan *cmd;
  62        struct uwb_rc_evt_confirm reply;
  63
  64        result = -ENOMEM;
  65        cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
  66        if (cmd == NULL)
  67                goto error_kzalloc;
  68        mutex_lock(&rc->uwb_dev.mutex);
  69        cmd->rccb.bCommandType = UWB_RC_CET_GENERAL;
  70        cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SCAN);
  71        cmd->bChannelNumber = channel;
  72        cmd->bScanState = type;
  73        cmd->wStartTime = cpu_to_le16(bpst_offset);
  74        reply.rceb.bEventType = UWB_RC_CET_GENERAL;
  75        reply.rceb.wEvent = UWB_RC_CMD_SCAN;
  76        result = uwb_rc_cmd(rc, "SCAN", &cmd->rccb, sizeof(*cmd),
  77                            &reply.rceb, sizeof(reply));
  78        if (result < 0)
  79                goto error_cmd;
  80        if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
  81                dev_err(&rc->uwb_dev.dev,
  82                        "SCAN: command execution failed: %s (%d)\n",
  83                        uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
  84                result = -EIO;
  85                goto error_cmd;
  86        }
  87        rc->scanning = channel;
  88        rc->scan_type = type;
  89error_cmd:
  90        mutex_unlock(&rc->uwb_dev.mutex);
  91        kfree(cmd);
  92error_kzalloc:
  93        return result;
  94}
  95
  96/*
  97 * Print scanning state
  98 */
  99static ssize_t uwb_rc_scan_show(struct device *dev,
 100                                struct device_attribute *attr, char *buf)
 101{
 102        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 103        struct uwb_rc *rc = uwb_dev->rc;
 104        ssize_t result;
 105
 106        mutex_lock(&rc->uwb_dev.mutex);
 107        result = sprintf(buf, "%d %d\n", rc->scanning, rc->scan_type);
 108        mutex_unlock(&rc->uwb_dev.mutex);
 109        return result;
 110}
 111
 112/*
 113 *
 114 */
 115static ssize_t uwb_rc_scan_store(struct device *dev,
 116                                 struct device_attribute *attr,
 117                                 const char *buf, size_t size)
 118{
 119        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 120        struct uwb_rc *rc = uwb_dev->rc;
 121        unsigned channel;
 122        unsigned type;
 123        unsigned bpst_offset = 0;
 124        ssize_t result = -EINVAL;
 125
 126        result = sscanf(buf, "%u %u %u\n", &channel, &type, &bpst_offset);
 127        if (result >= 2 && type < UWB_SCAN_TOP)
 128                result = uwb_rc_scan(rc, channel, type, bpst_offset);
 129
 130        return result < 0 ? result : size;
 131}
 132
 133/** Radio Control sysfs interface (declaration) */
 134DEVICE_ATTR(scan, S_IRUGO | S_IWUSR, uwb_rc_scan_show, uwb_rc_scan_store);
 135