/*
* WUSB Wire Adapter: Control/Data Streaming Interface (WUSB[8])
* MMC (Microscheduled Management Command) handling
*
* Copyright (C) 2005-2006 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.
*
*
* WUIEs and MMC IEs...well, they are almost the same at the end. MMC
* IEs are Wireless USB IEs that go into the MMC period...[what is
* that? look in Design-overview.txt].
*
*
* This is a simple subsystem to keep track of which IEs are being
* sent by the host in the MMC period.
*
* For each WUIE we ask to send, we keep it in an array, so we can
* request its removal later, or replace the content. They are tracked
* by pointer, so be sure to use the same pointer if you want to
* remove it or update the contents.
*
* FIXME:
* - add timers that autoremove intervalled IEs?
*/
#include <linux/usb/wusb.h>
#include <linux/slab.h>
#include "wusbhc.h"
/* Initialize the MMCIEs handling mechanism */
int wusbhc_mmcie_create(struct wusbhc *wusbhc)
{
u8 mmcies = wusbhc->mmcies_max;
wusbhc->mmcie = kcalloc(mmcies, sizeof(wusbhc->mmcie[0]), GFP_KERNEL);
if (wusbhc->mmcie == NULL)
return -ENOMEM;
mutex_init(&wusbhc->mmcie_mutex);
return 0;
}
/* Release resources used by the MMCIEs handling mechanism */
void wusbhc_mmcie_destroy(struct wusbhc *wusbhc)
{
kfree(wusbhc->mmcie);
}
/*
* Add or replace an MMC Wireless USB IE.
*
* @interval: See WUSB1.0[8.5.3.1]
* @repeat_cnt: See WUSB1.0[8.5.3.1]
* @handle: See WUSB1.0[8.5.3.1]
* @wuie: Pointer to the header of the WUSB IE data to add.
* MUST BE allocated in a kmalloc buffer (no stack or
* vmalloc).
* THE CALLER ALWAYS OWNS THE POINTER (we don't free it
* on remove, we just forget about it).
* @returns: 0 if ok, < 0 errno code on error.
*
* Goes over the *whole* @wusbhc->mmcie array looking for (a) the
* first free spot and (b) if @wuie is already in the array (aka:
* transmitted in the MMCs) the spot were it is.
*
* If present, we "overwrite it" (update).
*
*
* NOTE: Need special ordering rules -- see below WUSB1.0 Table 7-38.
* The host uses the handle as the 'sort' index. We
* allocate the last one always for the WUIE_ID_HOST_INFO, and
* the rest, first come first serve in inverse order.
*
* Host software must make sure that it adds the other IEs in
* the right order... the host hardware is responsible for
* placing the WCTA IEs in the right place with the other IEs
* set by host software.
*
* NOTE: we can access wusbhc->wa_descr without locking because it is
* read only.
*/
int wusbhc_mmcie_set(struct wusbhc *wusbhc, u8 interval, u8 repeat_cnt,
struct wuie_hdr *wuie)
{
int result = -ENOBUFS;
unsigned handle, itr;
/* Search a handle, taking into account the ordering */
mutex_lock(&wusbhc->mmcie_mutex);
switch (wuie->bIEIdentifier) {
case WUIE_ID_HOST_INFO:
/* Always last */
handle = wusbhc->mmcies_max - 1;
break;
case WUIE_ID_ISOCH_DISCARD:
dev_err(wusbhc->dev, "Special ordering case for WUIE ID 0x%x "
"unimplemented\n", wuie->bIEIdentifier);
result = -ENOSYS;
goto error_unlock;
default:
/* search for it or find the last empty slot */
handle = ~0;
for (itr = 0; itr < wusbhc->mmcies_max - 1; itr++) {
if (wusbhc->mmcie[itr] == wuie) {
handle = itr;
break;
}
if (wusbhc->mmcie[itr] == NULL)
handle = itr;
}
if (handle == ~0)
goto error_unlock;
}
result = (wusbhc->mmcie_add)(wusbhc, interval, repeat_cnt, handle,
wuie);
if (result >= 0)
wusbhc->mmcie[handle] = wuie;
error_unlock:
mutex_unlock(&wusbhc->mmcie_mutex);
return result;
}
EXPORT_SYMBOL_GPL(wusbhc_mmcie_set);
/*
* Remove an MMC IE previously added with wusbhc_mmcie_set()
*
* @wuie Pointer used to add the WUIE
*/
void wusbhc_mmcie_rm(struct wusbhc *wusbhc, struct wuie_hdr *wuie)
{
int result;
unsigned handle, itr;
mutex_lock(&wusbhc->mmcie_mutex);
for (itr = 0; itr < wusbhc->mmcies_max; itr++) {
if (wusbhc->mmcie[itr] == wuie) {
handle = itr;
goto found;
}
}
mutex_unlock(&wusbhc->mmcie_mutex);
return;
found:
result = (wusbhc->mmcie_rm)(wusbhc, handle);
if (result == 0)
wusbhc->mmcie[itr] = NULL;
mutex_unlock(&wusbhc->mmcie_mutex);
}
EXPORT_SYMBOL_GPL(wusbhc_mmcie_rm);
static int wusbhc_mmc_start(struct wusbhc *wusbhc)
{
int ret;
mutex_lock(&wusbhc->mutex);
ret = wusbhc->start(wusbhc);
if (ret >= 0)
wusbhc->active = 1;
mutex_unlock(&wusbhc->mutex);
return ret;
}
static void wusbhc_mmc_stop(struct wusbhc *wusbhc)
{
mutex_lock(&wusbhc->mutex);
wusbhc->active = 0;
wusbhc->stop(wusbhc, WUSB_CHANNEL_STOP_DELAY_MS);
mutex_unlock(&wusbhc->mutex);
}
/*
* wusbhc_start - start transmitting MMCs and accepting connections
* @wusbhc: the HC to start
*
* Establishes a cluster reservation, enables device connections, and
* starts MMCs with appropriate DNTS parameters.
*/
int wusbhc_start(struct wusbhc *wusbhc)
{
int result;
struct device *dev = wusbhc->dev;
WARN_ON(wusbhc->wuie_host_info != NULL);
result = wusbhc_rsv_establish(wusbhc);
if (result < 0) {
dev_err(dev, "cannot establish cluster reservation: %d\n",
result);
goto error_rsv_establish;
}
result = wusbhc_devconnect_start(wusbhc);
if (result < 0) {
dev_err(dev, "error enabling device connections: %d\n", result);
goto error_devconnect_start;
}
result = wusbhc_sec_start(wusbhc);
if (result < 0) {
dev_err(dev, "error starting security in the HC: %d\n", result);
goto error_sec_start;
}
/* FIXME: the choice of the DNTS parameters is somewhat
* arbitrary */
result = wusbhc->set_num_dnts(wusbhc, 0, 15);
if (result < 0) {
dev_err(dev, "Cannot set DNTS parameters: %d\n", result);
goto error_set_num_dnts;
}
result = wusbhc_mmc_start(wusbhc);
if (result < 0) {
dev_err(dev, "error starting wusbch: %d\n", result);
goto error_wusbhc_start;
}
return 0;
error_wusbhc_start:
wusbhc_sec_stop(wusbhc);
error_set_num_dnts:
error_sec_start:
wusbhc_devconnect_stop(wusbhc);
error_devconnect_start:
wusbhc_rsv_terminate(wusbhc);
error_rsv_establish:
return result;
}
/*
* wusbhc_stop - stop transmitting MMCs
* @wusbhc: the HC to stop
*
* Stops the WUSB channel and removes the cluster reservation.
*/
void wusbhc_stop(struct wusbhc *wusbhc)
{
wusbhc_mmc_stop(wusbhc);
wusbhc_sec_stop(wusbhc);
wusbhc_devconnect_stop(wusbhc);
wusbhc_rsv_terminate(wusbhc);
}
/*
* Set/reset/update a new CHID
*
* Depending on the previous state of the MMCs, start, stop or change
* the sent MMC. This effectively switches the host controller on and
* off (radio wise).
*/
int wusbhc_chid_set(struct wusbhc *wusbhc, const struct wusb_ckhdid *chid)
{
int result = 0;
if (memcmp(chid, &wusb_ckhdid_zero, sizeof(*chid)) == 0)
chid = NULL;
mutex_lock(&wusbhc->mutex);
if (chid) {
if (wusbhc->active) {
mutex_unlock(&wusbhc->mutex);
return -EBUSY;
}
wusbhc->chid = *chid;
}
mutex_unlock(&wusbhc->mutex);
if (chid)
result = uwb_radio_start(&wusbhc->pal);
else
uwb_radio_stop(&wusbhc->pal);
return result;
}
EXPORT_SYMBOL_GPL(wusbhc_chid_set);
