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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 "wusbhc.h"
41 
42 /* Initialize the MMCIEs handling mechanism */
wusbhc_mmcie_create(struct wusbhc * wusbhc)43 int wusbhc_mmcie_create(struct wusbhc *wusbhc)
44 {
45 	u8 mmcies = wusbhc->mmcies_max;
46 	wusbhc->mmcie = kcalloc(mmcies, sizeof(wusbhc->mmcie[0]), GFP_KERNEL);
47 	if (wusbhc->mmcie == NULL)
48 		return -ENOMEM;
49 	mutex_init(&wusbhc->mmcie_mutex);
50 	return 0;
51 }
52 
53 /* Release resources used by the MMCIEs handling mechanism */
wusbhc_mmcie_destroy(struct wusbhc * wusbhc)54 void wusbhc_mmcie_destroy(struct wusbhc *wusbhc)
55 {
56 	kfree(wusbhc->mmcie);
57 }
58 
59 /*
60  * Add or replace an MMC Wireless USB IE.
61  *
62  * @interval:    See WUSB1.0[8.5.3.1]
63  * @repeat_cnt:  See WUSB1.0[8.5.3.1]
64  * @handle:      See WUSB1.0[8.5.3.1]
65  * @wuie:        Pointer to the header of the WUSB IE data to add.
66  *               MUST BE allocated in a kmalloc buffer (no stack or
67  *               vmalloc).
68  *               THE CALLER ALWAYS OWNS THE POINTER (we don't free it
69  *               on remove, we just forget about it).
70  * @returns:     0 if ok, < 0 errno code on error.
71  *
72  * Goes over the *whole* @wusbhc->mmcie array looking for (a) the
73  * first free spot and (b) if @wuie is already in the array (aka:
74  * transmitted in the MMCs) the spot were it is.
75  *
76  * If present, we "overwrite it" (update).
77  *
78  *
79  * NOTE: Need special ordering rules -- see below WUSB1.0 Table 7-38.
80  *       The host uses the handle as the 'sort' index. We
81  *       allocate the last one always for the WUIE_ID_HOST_INFO, and
82  *       the rest, first come first serve in inverse order.
83  *
84  *       Host software must make sure that it adds the other IEs in
85  *       the right order... the host hardware is responsible for
86  *       placing the WCTA IEs in the right place with the other IEs
87  *       set by host software.
88  *
89  * NOTE: we can access wusbhc->wa_descr without locking because it is
90  *       read only.
91  */
wusbhc_mmcie_set(struct wusbhc * wusbhc,u8 interval,u8 repeat_cnt,struct wuie_hdr * wuie)92 int wusbhc_mmcie_set(struct wusbhc *wusbhc, u8 interval, u8 repeat_cnt,
93 		     struct wuie_hdr *wuie)
94 {
95 	int result = -ENOBUFS;
96 	unsigned handle, itr;
97 
98 	/* Search a handle, taking into account the ordering */
99 	mutex_lock(&wusbhc->mmcie_mutex);
100 	switch (wuie->bIEIdentifier) {
101 	case WUIE_ID_HOST_INFO:
102 		/* Always last */
103 		handle = wusbhc->mmcies_max - 1;
104 		break;
105 	case WUIE_ID_ISOCH_DISCARD:
106 		dev_err(wusbhc->dev, "Special ordering case for WUIE ID 0x%x "
107 			"unimplemented\n", wuie->bIEIdentifier);
108 		result = -ENOSYS;
109 		goto error_unlock;
110 	default:
111 		/* search for it or find the last empty slot */
112 		handle = ~0;
113 		for (itr = 0; itr < wusbhc->mmcies_max - 1; itr++) {
114 			if (wusbhc->mmcie[itr] == wuie) {
115 				handle = itr;
116 				break;
117 			}
118 			if (wusbhc->mmcie[itr] == NULL)
119 				handle = itr;
120 		}
121 		if (handle == ~0)
122 			goto error_unlock;
123 	}
124 	result = (wusbhc->mmcie_add)(wusbhc, interval, repeat_cnt, handle,
125 				     wuie);
126 	if (result >= 0)
127 		wusbhc->mmcie[handle] = wuie;
128 error_unlock:
129 	mutex_unlock(&wusbhc->mmcie_mutex);
130 	return result;
131 }
132 EXPORT_SYMBOL_GPL(wusbhc_mmcie_set);
133 
134 /*
135  * Remove an MMC IE previously added with wusbhc_mmcie_set()
136  *
137  * @wuie	Pointer used to add the WUIE
138  */
wusbhc_mmcie_rm(struct wusbhc * wusbhc,struct wuie_hdr * wuie)139 void wusbhc_mmcie_rm(struct wusbhc *wusbhc, struct wuie_hdr *wuie)
140 {
141 	int result;
142 	unsigned handle, itr;
143 
144 	mutex_lock(&wusbhc->mmcie_mutex);
145 	for (itr = 0; itr < wusbhc->mmcies_max; itr++) {
146 		if (wusbhc->mmcie[itr] == wuie) {
147 			handle = itr;
148 			goto found;
149 		}
150 	}
151 	mutex_unlock(&wusbhc->mmcie_mutex);
152 	return;
153 
154 found:
155 	result = (wusbhc->mmcie_rm)(wusbhc, handle);
156 	if (result == 0)
157 		wusbhc->mmcie[itr] = NULL;
158 	mutex_unlock(&wusbhc->mmcie_mutex);
159 }
160 EXPORT_SYMBOL_GPL(wusbhc_mmcie_rm);
161 
wusbhc_mmc_start(struct wusbhc * wusbhc)162 static int wusbhc_mmc_start(struct wusbhc *wusbhc)
163 {
164 	int ret;
165 
166 	mutex_lock(&wusbhc->mutex);
167 	ret = wusbhc->start(wusbhc);
168 	if (ret >= 0)
169 		wusbhc->active = 1;
170 	mutex_unlock(&wusbhc->mutex);
171 
172 	return ret;
173 }
174 
wusbhc_mmc_stop(struct wusbhc * wusbhc)175 static void wusbhc_mmc_stop(struct wusbhc *wusbhc)
176 {
177 	mutex_lock(&wusbhc->mutex);
178 	wusbhc->active = 0;
179 	wusbhc->stop(wusbhc, WUSB_CHANNEL_STOP_DELAY_MS);
180 	mutex_unlock(&wusbhc->mutex);
181 }
182 
183 /*
184  * wusbhc_start - start transmitting MMCs and accepting connections
185  * @wusbhc: the HC to start
186  *
187  * Establishes a cluster reservation, enables device connections, and
188  * starts MMCs with appropriate DNTS parameters.
189  */
wusbhc_start(struct wusbhc * wusbhc)190 int wusbhc_start(struct wusbhc *wusbhc)
191 {
192 	int result;
193 	struct device *dev = wusbhc->dev;
194 
195 	WARN_ON(wusbhc->wuie_host_info != NULL);
196 
197 	result = wusbhc_rsv_establish(wusbhc);
198 	if (result < 0) {
199 		dev_err(dev, "cannot establish cluster reservation: %d\n",
200 			result);
201 		goto error_rsv_establish;
202 	}
203 
204 	result = wusbhc_devconnect_start(wusbhc);
205 	if (result < 0) {
206 		dev_err(dev, "error enabling device connections: %d\n", result);
207 		goto error_devconnect_start;
208 	}
209 
210 	result = wusbhc_sec_start(wusbhc);
211 	if (result < 0) {
212 		dev_err(dev, "error starting security in the HC: %d\n", result);
213 		goto error_sec_start;
214 	}
215 	/* FIXME: the choice of the DNTS parameters is somewhat
216 	 * arbitrary */
217 	result = wusbhc->set_num_dnts(wusbhc, 0, 15);
218 	if (result < 0) {
219 		dev_err(dev, "Cannot set DNTS parameters: %d\n", result);
220 		goto error_set_num_dnts;
221 	}
222 	result = wusbhc_mmc_start(wusbhc);
223 	if (result < 0) {
224 		dev_err(dev, "error starting wusbch: %d\n", result);
225 		goto error_wusbhc_start;
226 	}
227 
228 	return 0;
229 
230 error_wusbhc_start:
231 	wusbhc_sec_stop(wusbhc);
232 error_set_num_dnts:
233 error_sec_start:
234 	wusbhc_devconnect_stop(wusbhc);
235 error_devconnect_start:
236 	wusbhc_rsv_terminate(wusbhc);
237 error_rsv_establish:
238 	return result;
239 }
240 
241 /*
242  * wusbhc_stop - stop transmitting MMCs
243  * @wusbhc: the HC to stop
244  *
245  * Stops the WUSB channel and removes the cluster reservation.
246  */
wusbhc_stop(struct wusbhc * wusbhc)247 void wusbhc_stop(struct wusbhc *wusbhc)
248 {
249 	wusbhc_mmc_stop(wusbhc);
250 	wusbhc_sec_stop(wusbhc);
251 	wusbhc_devconnect_stop(wusbhc);
252 	wusbhc_rsv_terminate(wusbhc);
253 }
254 
255 /*
256  * Set/reset/update a new CHID
257  *
258  * Depending on the previous state of the MMCs, start, stop or change
259  * the sent MMC. This effectively switches the host controller on and
260  * off (radio wise).
261  */
wusbhc_chid_set(struct wusbhc * wusbhc,const struct wusb_ckhdid * chid)262 int wusbhc_chid_set(struct wusbhc *wusbhc, const struct wusb_ckhdid *chid)
263 {
264 	int result = 0;
265 
266 	if (memcmp(chid, &wusb_ckhdid_zero, sizeof(chid)) == 0)
267 		chid = NULL;
268 
269 	mutex_lock(&wusbhc->mutex);
270 	if (chid) {
271 		if (wusbhc->active) {
272 			mutex_unlock(&wusbhc->mutex);
273 			return -EBUSY;
274 		}
275 		wusbhc->chid = *chid;
276 	}
277 	mutex_unlock(&wusbhc->mutex);
278 
279 	if (chid)
280 		result = uwb_radio_start(&wusbhc->pal);
281 	else
282 		uwb_radio_stop(&wusbhc->pal);
283 	return result;
284 }
285 EXPORT_SYMBOL_GPL(wusbhc_chid_set);
286