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 Controller
 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);