path: root/drivers/usb/wusbcore/devconnect.c

/*
 * WUSB Wire Adapter: Control/Data Streaming Interface (WUSB[8])
 * Device Connect handling
 *
 * Copyright (C) 2006 Intel Corporation
 * 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.
 *
 *
 * FIXME: docs
 * FIXME: this file needs to be broken up, it's grown too big
 *
 *
 * WUSB1.0[7.1, 7.5.1, ]
 *
 * WUSB device connection is kind of messy. Some background:
 *
 *     When a device wants to connect it scans the UWB radio channels
 *     looking for a WUSB Channel; a WUSB channel is defined by MMCs
 *     (Micro Managed Commands or something like that) [see
 *     Design-overview for more on this] .
 *
 * So, device scans the radio, finds MMCs and thus a host and checks
 * when the next DNTS is. It sends a Device Notification Connect
 * (DN_Connect); the host picks it up (through nep.c and notif.c, ends
 * up in wusb_devconnect_ack(), which creates a wusb_dev structure in
 * wusbhc->port[port_number].wusb_dev), assigns an unauth address
 * to the device (this means from 0x80 to 0xfe) and sends, in the MMC
 * a Connect Ack Information Element (ConnAck IE).
 *
 * So now the device now has a WUSB address. From now on, we use
 * that to talk to it in the RPipes.
 *
 * ASSUMPTIONS:
 *
 *  - We use the the as device address the port number where it is
 *    connected (port 0 doesn't exist). For unauth, it is 128 + that.
 *
 * ROADMAP:
 *
 *   This file contains the logic for doing that--entry points:
 *
 *   wusb_devconnect_ack()      Ack a device until _acked() called.
 *                              Called by notif.c:wusb_handle_dn_connect()
 *                              when a DN_Connect is received.
 *
 *     wusb_devconnect_acked()  Ack done, release resources.
 *
 *   wusb_handle_dn_alive()     Called by notif.c:wusb_handle_dn()
 *                              for processing a DN_Alive pong from a device.
 *
 *   wusb_handle_dn_disconnect()Called by notif.c:wusb_handle_dn() to
 *                              process a disconenct request from a
 *                              device.
 *
 *   __wusb_dev_disable()       Called by rh.c:wusbhc_rh_clear_port_feat() when
 *                              disabling a port.
 *
 *   wusb_devconnect_create()   Called when creating the host by
 *                              lc.c:wusbhc_create().
 *
 *   wusb_devconnect_destroy()  Cleanup called removing the host. Called
 *                              by lc.c:wusbhc_destroy().
 *
 *   Each Wireless USB host maintains a list of DN_Connect requests
 *   (actually we maintain a list of pending Connect Acks, the
 *   wusbhc->ca_list).
 *
 * LIFE CYCLE OF port->wusb_dev
 *
 *   Before the @wusbhc structure put()s the reference it owns for
 *   port->wusb_dev [and clean the wusb_dev pointer], it needs to
 *   lock @wusbhc->mutex.
 */

#include <linux/jiffies.h>
#include <linux/ctype.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/export.h>
#include "wusbhc.h"

static void wusbhc_devconnect_acked_work(struct work_struct *work);

static void wusb_dev_free(struct wusb_dev *wusb_dev)
{
	kfree(wusb_dev);
}

static struct wusb_dev *wusb_dev_alloc(struct wusbhc *wusbhc)
{
	struct wusb_dev *wusb_dev;

	wusb_dev = kzalloc(sizeof(*wusb_dev), GFP_KERNEL);
	if (wusb_dev == NULL)
		goto err;

	wusb_dev->wusbhc = wusbhc;

	INIT_WORK(&wusb_dev->devconnect_acked_work, wusbhc_devconnect_acked_work);

	return wusb_dev;
err:
	wusb_dev_free(wusb_dev);
	return NULL;
}


/*
 * Using the Connect-Ack list, fill out the @wusbhc Connect-Ack WUSB IE
 * properly so that it can be added to the MMC.
 *
 * We just get the @wusbhc->ca_list and fill out the first four ones or
 * less (per-spec WUSB1.0[7.5, before T7-38). If the ConnectAck WUSB
 * IE is not allocated, we alloc it.
 *
 * @wusbhc->mutex must be taken
 */
static void wusbhc_fill_cack_ie(struct wusbhc *wusbhc)
{
	unsigned cnt;
	struct wusb_dev *dev_itr;
	struct wuie_connect_ack *cack_ie;

	cack_ie = &wusbhc->cack_ie;
	cnt = 0;
	list_for_each_entry(dev_itr, &wusbhc->cack_list, cack_node) {
		cack_ie->blk[cnt].CDID = dev_itr->cdid;
		cack_ie->blk[cnt].bDeviceAddress = dev_itr->addr;
		if (++cnt >= WUIE_ELT_MAX)
			break;
	}
	cack_ie->hdr.bLength = sizeof(cack_ie->hdr)
		+ cnt * sizeof(cack_ie->blk[0]);
}

/*
 * Register a new device that wants to connect
 *
 * A new device wants to connect, so we add it to the Connect-Ack
 * list. We give it an address in the unauthorized range (bit 8 set);
 * user space will have to drive authorization further on.
 *
 * @dev_addr: address to use for the device (which is also the port
 *            number).
 *
 * @wusbhc->mutex must be taken
 */
static struct wusb_dev *wusbhc_cack_add(struct wusbhc *wusbhc,
					struct wusb_dn_connect *dnc,
					const char *pr_cdid, u8 port_idx)
{
	struct device *dev = wusbhc->dev;
	struct wusb_dev *wusb_dev;
	int new_connection = wusb_dn_connect_new_connection(dnc);
	u8 dev_addr;
	int result;

	/* Is it registered already? */
	list_for_each_entry(wusb_dev, &wusbhc->cack_list, cack_node)
		if (!memcmp(&wusb_dev->cdid, &dnc->CDID,
			    sizeof(wusb_dev->cdid)))
			return wusb_dev;
	/* We don't have it, create an entry, register it */
	wusb_dev = wusb_dev_alloc(wusbhc);
	if (wusb_dev == NULL)
		return NULL;
	wusb_dev_init(wusb_dev);
	wusb_dev->cdid = dnc->CDID;
	wusb_dev->port_idx