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

/*
 * Intel Wireless WiMAX Connection 2400m
 * Generic probe/disconnect, reset and message passing
 *
 *
 * Copyright (C) 2007-2008 Intel Corporation <linux-wimax@intel.com>
 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 *
 * See i2400m.h for driver documentation. This contains helpers for
 * the driver model glue [_setup()/_release()], handling device resets
 * [_dev_reset_handle()], and the backends for the WiMAX stack ops
 * reset [_op_reset()] and message from user [_op_msg_from_user()].
 *
 * ROADMAP:
 *
 * i2400m_op_msg_from_user()
 *   i2400m_msg_to_dev()
 *   wimax_msg_to_user_send()
 *
 * i2400m_op_reset()
 *   i240m->bus_reset()
 *
 * i2400m_dev_reset_handle()
 *   __i2400m_dev_reset_handle()
 *     __i2400m_dev_stop()
 *     __i2400m_dev_start()
 *
 * i2400m_setup()
 *   i2400m->bus_setup()
 *   i2400m_bootrom_init()
 *   register_netdev()
 *   wimax_dev_add()
 *   i2400m_dev_start()
 *     __i2400m_dev_start()
 *       i2400m_dev_bootstrap()
 *       i2400m_tx_setup()
 *       i2400m->bus_dev_start()
 *       i2400m_firmware_check()
 *       i2400m_check_mac_addr()
 *
 * i2400m_release()
 *   i2400m_dev_stop()
 *     __i2400m_dev_stop()
 *       i2400m_dev_shutdown()
 *       i2400m->bus_dev_stop()
 *       i2400m_tx_release()
 *   i2400m->bus_release()
 *   wimax_dev_rm()
 *   unregister_netdev()
 */
#include "i2400m.h"
#include <linux/etherdevice.h>
#include <linux/wimax/i2400m.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/suspend.h>
#include <linux/slab.h>

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


static char i2400m_debug_params[128];
module_param_string(debug, i2400m_debug_params, sizeof(i2400m_debug_params),
		    0644);
MODULE_PARM_DESC(debug,
		 "String of space-separated NAME:VALUE pairs, where NAMEs "
		 "are the different debug submodules and VALUE are the "
		 "initial debug value to set.");

static char i2400m_barkers_params[128];
module_param_string(barkers, i2400m_barkers_params,
		    sizeof(i2400m_barkers_params), 0644);
MODULE_PARM_DESC(barkers,
		 "String of comma-separated 32-bit values; each is "
		 "recognized as the value the device sends as a reboot "
		 "signal; values are appended to a list--setting one value "
		 "as zero cleans the existing list and starts a new one.");

static
struct i2400m_work *__i2400m_work_setup(
	struct i2400m *i2400m, void (*fn)(struct work_struct *),
	gfp_t gfp_flags, const void *pl, size_t pl_size)
{
	struct i2400m_work *iw;

	iw = kzalloc(sizeof(*iw) + pl_size, gfp_flags);
	if (iw == NULL)
		return NULL;
	iw->i2400m = i2400m_get(i2400m);
	iw->pl_size = pl_size;
	memcpy(iw->pl, pl, pl_size);
	INIT_WORK(&iw->ws, fn);
	return iw;
}


/*
 * Schedule i2400m's specific work on the system's queue.
 *
 * Used for a few cases where we really need it; otherwise, identical
 * to i2400m_queue_work().
 *
 * Returns < 0 errno code on error, 1 if ok.
 *
 * If it returns zero, something really bad happened, as it means the
 * works struct was already queued, but we have just allocated it, so
 * it should not happen.
 */
static int i2400m_schedule_work(struct i2400m *i2400m,
			 void (*fn)(struct work_struct *), gfp_t gfp_flags,
			 const void *pl, size_t pl_size)
{
	int result;
	struct i2400m_work *iw;

	result = -ENOMEM;
	iw = __i2400m_work_setup(i2400m, fn, gfp_flags, pl, pl_size);
	if (iw != NULL) {
		result = schedule_work(&iw->ws);
		if (WARN_ON(result == 0))
			result = -ENXIO;
	}
	return result;
}


/*
 * WiMAX stack operation: relay a message from user space
 *
 * @wimax_dev: device descriptor
 * @pipe_name: named pipe the message is for
 * @msg_buf: pointer to the message bytes
 * @msg_len: length of the buffer
 * @genl_info: passed by the generic netlink layer
 *
 * The WiMAX stack will call this function when a message was received
 * from user space.
 *
 * For the i2400m, this is an L3L4 message, as specified in
 * include/linux/wimax/i2400m.h, and thus prefixed with a 'struct
 * i2400m_l3l4_hdr'. Driver (and device) expect the messages to be
 * coded in Little Endian.
 *
 * This function just verifies that the header declaration and the
 * payload are consistent and then deals with it, either forwarding it
 * to the device or procesing it locally.
 *
 * In the i2400m, messages are basically commands that will carry an
 * ack, so we use i2400m_msg_to_dev() and then deliver the ack back to
 * user space. The rx.c code might intercept the response and use it
 * to update the driver's state, but then it will pass it on so it can
 * be relayed back to user space.
 *
 * Note that asynchronous events from the device are processed and
 * sent to user space in rx.c.
 */
static
int i2400m_op_msg_from_user(struct wimax_dev *wimax_dev,
			    const char *pipe_name,
			    const void *msg_buf, size_t msg_len,
			    const struct genl_info *genl_info)
{
	int result;
	struct i2400m *i2400m = wimax_dev_to_i2400m(wimax_dev);
	struct device *dev = i2400m_dev(i2400m);
	struct sk_buff *ack_skb;

	d_fnstart(4, dev, "(wimax_dev %p [i2400m %p] msg_buf %p "
		  "msg_len %zu genl_info %p)\n"