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 */
45int 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 */
56void 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 */
94int 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;
130error_unlock:
131	mutex_unlock(&wusbhc->mmcie_mutex);
132	return result;
133}
134EXPORT_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 */
141void 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
156found:
157	result = (wusbhc->mmcie_rm)(wusbhc, handle);
158	if (result == 0)
159		wusbhc->mmcie[itr] = NULL;
160	mutex_unlock(&wusbhc->mmcie_mutex);
161}
162EXPORT_SYMBOL_GPL(wusbhc_mmcie_rm);
163
164static 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
177static 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 */
192int 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
235error_wusbhc_start:
236	wusbhc_sec_stop(wusbhc);
237error_set_num_dnts:
238error_sec_start:
239	wusbhc_devconnect_stop(wusbhc);
240error_devconnect_start:
241	wusbhc_rsv_terminate(wusbhc);
242error_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 */
252void 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 */
267int 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
309error_pal_register:
310	uwb_rc_put(wusbhc->uwb_rc);
311	wusbhc->uwb_rc = NULL;
312error_rc_get:
313	mutex_unlock(&wusbhc->mutex);
314
315	return result;
316}
317EXPORT_SYMBOL_GPL(wusbhc_chid_set);
318