1 /*
2 * WUSB Wire Adapter: Control/Data Streaming Interface (WUSB[8])
3 * MMC (Microscheduled Management Command) handling
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 * WUIEs and MMC IEs...well, they are almost the same at the end. MMC
24 * IEs are Wireless USB IEs that go into the MMC period...[what is
25 * that? look in Design-overview.txt].
26 *
27 *
28 * This is a simple subsystem to keep track of which IEs are being
29 * sent by the host in the MMC period.
30 *
31 * For each WUIE we ask to send, we keep it in an array, so we can
32 * request its removal later, or replace the content. They are tracked
33 * by pointer, so be sure to use the same pointer if you want to
34 * remove it or update the contents.
35 *
36 * FIXME:
37 * - add timers that autoremove intervalled IEs?
38 */
39 #include <linux/usb/wusb.h>
40 #include <linux/slab.h>
41 #include <linux/export.h>
42 #include "wusbhc.h"
43
44 /* Initialize the MMCIEs handling mechanism */
wusbhc_mmcie_create(struct wusbhc * wusbhc)45 int wusbhc_mmcie_create(struct wusbhc *wusbhc)
46 {
47 u8 mmcies = wusbhc->mmcies_max;
48 wusbhc->mmcie = kcalloc(mmcies, sizeof(wusbhc->mmcie[0]), GFP_KERNEL);
49 if (wusbhc->mmcie == NULL)
50 return -ENOMEM;
51 mutex_init(&wusbhc->mmcie_mutex);
52 return 0;
53 }
54
55 /* Release resources used by the MMCIEs handling mechanism */
wusbhc_mmcie_destroy(struct wusbhc * wusbhc)56 void wusbhc_mmcie_destroy(struct wusbhc *wusbhc)
57 {
58 kfree(wusbhc->mmcie);
59 }
60
61 /*
62 * Add or replace an MMC Wireless USB IE.
63 *
64 * @interval: See WUSB1.0[8.5.3.1]
65 * @repeat_cnt: See WUSB1.0[8.5.3.1]
66 * @handle: See WUSB1.0[8.5.3.1]
67 * @wuie: Pointer to the header of the WUSB IE data to add.
68 * MUST BE allocated in a kmalloc buffer (no stack or
69 * vmalloc).
70 * THE CALLER ALWAYS OWNS THE POINTER (we don't free it
71 * on remove, we just forget about it).
72 * @returns: 0 if ok, < 0 errno code on error.
73 *
74 * Goes over the *whole* @wusbhc->mmcie array looking for (a) the
75 * first free spot and (b) if @wuie is already in the array (aka:
76 * transmitted in the MMCs) the spot were it is.
77 *
78 * If present, we "overwrite it" (update).
79 *
80 *
81 * NOTE: Need special ordering rules -- see below WUSB1.0 Table 7-38.
82 * The host uses the handle as the 'sort' index. We
83 * allocate the last one always for the WUIE_ID_HOST_INFO, and
84 * the rest, first come first serve in inverse order.
85 *
86 * Host software must make sure that it adds the other IEs in
87 * the right order... the host hardware is responsible for
88 * placing the WCTA IEs in the right place with the other IEs
89 * set by host software.
90 *
91 * NOTE: we can access wusbhc->wa_descr without locking because it is
92 * read only.
93 */
wusbhc_mmcie_set(struct wusbhc * wusbhc,u8 interval,u8 repeat_cnt,struct wuie_hdr * wuie)94 int wusbhc_mmcie_set(struct wusbhc *wusbhc, u8 interval, u8 repeat_cnt,
95 struct wuie_hdr *wuie)
96 {
97 int result = -ENOBUFS;
98 unsigned handle, itr;
99
100 /* Search a handle, taking into account the ordering */
101 mutex_lock(&wusbhc->mmcie_mutex);
102 switch (wuie->bIEIdentifier) {
103 case WUIE_ID_HOST_INFO:
104 /* Always last */
105 handle = wusbhc->mmcies_max - 1;
106 break;
107 case WUIE_ID_ISOCH_DISCARD:
108 dev_err(wusbhc->dev, "Special ordering case for WUIE ID 0x%x "
109 "unimplemented\n", wuie->bIEIdentifier);
110 result = -ENOSYS;
111 goto error_unlock;
112 default:
113 /* search for it or find the last empty slot */
114 handle = ~0;
115 for (itr = 0; itr < wusbhc->mmcies_max - 1; itr++) {
116 if (wusbhc->mmcie[itr] == wuie) {
117 handle = itr;
118 break;
119 }
120 if (wusbhc->mmcie[itr] == NULL)
121 handle = itr;
122 }
123 if (handle == ~0)
124 goto error_unlock;
125 }
126 result = (wusbhc->mmcie_add)(wusbhc, interval, repeat_cnt, handle,
127 wuie);
128 if (result >= 0)
129 wusbhc->mmcie[handle] = wuie;
130 error_unlock:
131 mutex_unlock(&wusbhc->mmcie_mutex);
132 return result;
133 }
134 EXPORT_SYMBOL_GPL(wusbhc_mmcie_set);
135
136 /*
137 * Remove an MMC IE previously added with wusbhc_mmcie_set()
138 *
139 * @wuie Pointer used to add the WUIE
140 */
wusbhc_mmcie_rm(struct wusbhc * wusbhc,struct wuie_hdr * wuie)141 void wusbhc_mmcie_rm(struct wusbhc *wusbhc, struct wuie_hdr *wuie)
142 {
143 int result;
144 unsigned handle, itr;
145
146 mutex_lock(&wusbhc->mmcie_mutex);
147 for (itr = 0; itr < wusbhc->mmcies_max; itr++) {
148 if (wusbhc->mmcie[itr] == wuie) {
149 handle = itr;
150 goto found;
151 }
152 }
153 mutex_unlock(&wusbhc->mmcie_mutex);
154 return;
155
156 found:
157 result = (wusbhc->mmcie_rm)(wusbhc, handle);
158 if (result == 0)
159 wusbhc->mmcie[itr] = NULL;
160 mutex_unlock(&wusbhc->mmcie_mutex);
161 }
162 EXPORT_SYMBOL_GPL(wusbhc_mmcie_rm);
163
wusbhc_mmc_start(struct wusbhc * wusbhc)164 static int wusbhc_mmc_start(struct wusbhc *wusbhc)
165 {
166 int ret;
167
168 mutex_lock(&wusbhc->mutex);
169 ret = wusbhc->start(wusbhc);
170 if (ret >= 0)
171 wusbhc->active = 1;
172 mutex_unlock(&wusbhc->mutex);
173
174 return ret;
175 }
176
wusbhc_mmc_stop(struct wusbhc * wusbhc)177 static void wusbhc_mmc_stop(struct wusbhc *wusbhc)
178 {
179 mutex_lock(&wusbhc->mutex);
180 wusbhc->active = 0;
181 wusbhc->stop(wusbhc, WUSB_CHANNEL_STOP_DELAY_MS);
182 mutex_unlock(&wusbhc->mutex);
183 }
184
185 /*
186 * wusbhc_start - start transmitting MMCs and accepting connections
187 * @wusbhc: the HC to start
188 *
189 * Establishes a cluster reservation, enables device connections, and
190 * starts MMCs with appropriate DNTS parameters.
191 */
wusbhc_start(struct wusbhc * wusbhc)192 int wusbhc_start(struct wusbhc *wusbhc)
193 {
194 int result;
195 struct device *dev = wusbhc->dev;
196
197 WARN_ON(wusbhc->wuie_host_info != NULL);
198 BUG_ON(wusbhc->uwb_rc == NULL);
199
200 result = wusbhc_rsv_establish(wusbhc);
201 if (result < 0) {
202 dev_err(dev, "cannot establish cluster reservation: %d\n",
203 result);
204 goto error_rsv_establish;
205 }
206
207 result = wusbhc_devconnect_start(wusbhc);
208 if (result < 0) {
209 dev_err(dev, "error enabling device connections: %d\n",
210 result);
211 goto error_devconnect_start;
212 }
213
214 result = wusbhc_sec_start(wusbhc);
215 if (result < 0) {
216 dev_err(dev, "error starting security in the HC: %d\n",
217 result);
218 goto error_sec_start;
219 }
220
221 result = wusbhc->set_num_dnts(wusbhc, wusbhc->dnts_interval,
222 wusbhc->dnts_num_slots);
223 if (result < 0) {
224 dev_err(dev, "Cannot set DNTS parameters: %d\n", result);
225 goto error_set_num_dnts;
226 }
227 result = wusbhc_mmc_start(wusbhc);
228 if (result < 0) {
229 dev_err(dev, "error starting wusbch: %d\n", result);
230 goto error_wusbhc_start;
231 }
232
233 return 0;
234
235 error_wusbhc_start:
236 wusbhc_sec_stop(wusbhc);
237 error_set_num_dnts:
238 error_sec_start:
239 wusbhc_devconnect_stop(wusbhc);
240 error_devconnect_start:
241 wusbhc_rsv_terminate(wusbhc);
242 error_rsv_establish:
243 return result;
244 }
245
246 /*
247 * wusbhc_stop - stop transmitting MMCs
248 * @wusbhc: the HC to stop
249 *
250 * Stops the WUSB channel and removes the cluster reservation.
251 */
wusbhc_stop(struct wusbhc * wusbhc)252 void wusbhc_stop(struct wusbhc *wusbhc)
253 {
254 wusbhc_mmc_stop(wusbhc);
255 wusbhc_sec_stop(wusbhc);
256 wusbhc_devconnect_stop(wusbhc);
257 wusbhc_rsv_terminate(wusbhc);
258 }
259
260 /*
261 * Set/reset/update a new CHID
262 *
263 * Depending on the previous state of the MMCs, start, stop or change
264 * the sent MMC. This effectively switches the host controller on and
265 * off (radio wise).
266 */
wusbhc_chid_set(struct wusbhc * wusbhc,const struct wusb_ckhdid * chid)267 int wusbhc_chid_set(struct wusbhc *wusbhc, const struct wusb_ckhdid *chid)
268 {
269 int result = 0;
270
271 if (memcmp(chid, &wusb_ckhdid_zero, sizeof(*chid)) == 0)
272 chid = NULL;
273
274 mutex_lock(&wusbhc->mutex);
275 if (chid) {
276 if (wusbhc->active) {
277 mutex_unlock(&wusbhc->mutex);
278 return -EBUSY;
279 }
280 wusbhc->chid = *chid;
281 }
282
283 /* register with UWB if we haven't already since we are about to start
284 the radio. */
285 if ((chid) && (wusbhc->uwb_rc == NULL)) {
286 wusbhc->uwb_rc = uwb_rc_get_by_grandpa(wusbhc->dev->parent);
287 if (wusbhc->uwb_rc == NULL) {
288 result = -ENODEV;
289 dev_err(wusbhc->dev,
290 "Cannot get associated UWB Host Controller\n");
291 goto error_rc_get;
292 }
293
294 result = wusbhc_pal_register(wusbhc);
295 if (result < 0) {
296 dev_err(wusbhc->dev, "Cannot register as a UWB PAL\n");
297 goto error_pal_register;
298 }
299 }
300 mutex_unlock(&wusbhc->mutex);
301
302 if (chid)
303 result = uwb_radio_start(&wusbhc->pal);
304 else if (wusbhc->uwb_rc)
305 uwb_radio_stop(&wusbhc->pal);
306
307 return result;
308
309 error_pal_register:
310 uwb_rc_put(wusbhc->uwb_rc);
311 wusbhc->uwb_rc = NULL;
312 error_rc_get:
313 mutex_unlock(&wusbhc->mutex);
314
315 return result;
316 }
317 EXPORT_SYMBOL_GPL(wusbhc_chid_set);
318