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  */
  56 int 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;
  89 error_cmd:
  90         mutex_unlock(&rc->uwb_dev.mutex);
  91         kfree(cmd);
  92 error_kzalloc:
  93         return result;
  94 }
  95
  96 /*
  97  * Print scanning state
  98  */
  99 static 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  */
 115 static 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) */
 134 DEVICE_ATTR(scan, S_IRUGO | S_IWUSR, uwb_rc_scan_show, uwb_rc_scan_store);