path: root/drivers/net/wimax/i2400m/control.c

/*
 * Intel Wireless WiMAX Connection 2400m
 * Miscellaneous control functions for managing the device
 *
 *
 * Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *   * Neither the name of Intel Corporation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * Intel Corporation <linux-wimax@intel.com>
 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
 *  - Initial implementation
 *
 * This is a collection of functions used to control the device (plus
 * a few helpers).
 *
 * There are utilities for handling TLV buffers, hooks on the device's
 * reports to act on device changes of state [i2400m_report_hook()],
 * on acks to commands [i2400m_msg_ack_hook()], a helper for sending
 * commands to the device and blocking until a reply arrives
 * [i2400m_msg_to_dev()], a few high level commands for manipulating
 * the device state, powersving mode and configuration plus the
 * routines to setup the device once communication is stablished with
 * it [i2400m_dev_initialize()].
 *
 * ROADMAP
 *
 * i2400m_dev_initalize()       Called by i2400m_dev_start()
 *   i2400m_set_init_config()
 *   i2400m_firmware_check()
 *   i2400m_cmd_get_state()
 * i2400m_dev_shutdown()        Called by i2400m_dev_stop()
 *   i2400m->bus_reset()
 *
 * i2400m_{cmd,get,set}_*()
 *   i2400m_msg_to_dev()
 *   i2400m_msg_check_status()
 *
 * i2400m_report_hook()         Called on reception of an event
 *   i2400m_report_state_hook()
 *     i2400m_tlv_buffer_walk()
 *     i2400m_tlv_match()
 *     i2400m_report_tlv_system_state()
 *     i2400m_report_tlv_rf_switches_status()
 *     i2400m_report_tlv_media_status()
 *   i2400m_cmd_enter_powersave()
 *
 * i2400m_msg_ack_hook()        Called on reception of a reply to a
 *                              command, get or set
 */

#include <stdarg.h>
#include "i2400m.h"
#include <linux/kernel.h>
#include <linux/wimax/i2400m.h>


#define D_SUBMODULE control
#include "debug-levels.h"


/*
 * Return if a TLV is of a give type and size
 *
 * @tlv_hdr: pointer to the TLV
 * @tlv_type: type of the TLV we are looking for
 * @tlv_size: expected size of the TLV we are looking for (if -1,
 *            don't check the size). This includes the header
 * Returns: 0 if the TLV matches
 *          < 0 if it doesn't match at all
 *          > 0 total TLV + payload size, if the type matches, but not
 *              the size
 */
static
ssize_t i2400m_tlv_match(const struct i2400m_tlv_hdr *tlv,
		     enum i2400m_tlv tlv_type, ssize_t tlv_size)
{
	if (le16_to_cpu(tlv->type) != tlv_type)	/* Not our type? skip */
		return -1;
	if (tlv_size != -1
	    && le16_to_cpu(tlv->length) + sizeof(*tlv) != tlv_size) {
		size_t size = le16_to_cpu(tlv->length) + sizeof(*tlv);
		printk(KERN_WARNING "W: tlv type 0x%x mismatched because of "
		       "size (got %zu vs %zu expected)\n",
		       tlv_type, size, tlv_size);
		return size;
	}
	return 0;
}


/*
 * Given a buffer of TLVs, iterate over them
 *
 * @i2400m: device instance
 * @tlv_buf: pointer to the beginning of the TLV buffer
 * @buf_size: buffer size in bytes
 * @tlv_pos: seek position; this is assumed to be a pointer returned
 *           by i2400m_tlv_buffer_walk() [and thus, validated]. The
 *           TLV returned will be the one following this one.
 *
 * Usage:
 *
 * tlv_itr = NULL;
 * while (tlv_itr = i2400m_tlv_buffer_walk(i2400m, buf, size, tlv_itr))  {
 *         ...
 *         // Do stuff with tlv_itr, DON'T MODIFY IT
 *         ...
 * }
 */
static
const struct i2400m_tlv_hdr *i2400m_tlv_buffer_walk(
	struct i2400m *i2400m,
	const void *tlv_buf, size_t buf_size,
	const struct i2400m_tlv_hdr *