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df365423 IPG |
1 | /* |
2 | * WUSB Wire Adapter: Control/Data Streaming Interface (WUSB[8]) | |
3 | * Notification EndPoint support | |
4 | * | |
5 | * Copyright (C) 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 | * This part takes care of getting the notification from the hw | |
24 | * only and dispatching through wusbwad into | |
25 | * wa_notif_dispatch. Handling is done there. | |
26 | * | |
27 | * WA notifications are limited in size; most of them are three or | |
28 | * four bytes long, and the longest is the HWA Device Notification, | |
29 | * which would not exceed 38 bytes (DNs are limited in payload to 32 | |
30 | * bytes plus 3 bytes header (WUSB1.0[7.6p2]), plus 3 bytes HWA | |
31 | * header (WUSB1.0[8.5.4.2]). | |
32 | * | |
33 | * It is not clear if more than one Device Notification can be packed | |
34 | * in a HWA Notification, I assume no because of the wording in | |
35 | * WUSB1.0[8.5.4.2]. In any case, the bigger any notification could | |
36 | * get is 256 bytes (as the bLength field is a byte). | |
37 | * | |
38 | * So what we do is we have this buffer and read into it; when a | |
39 | * notification arrives we schedule work to a specific, single thread | |
40 | * workqueue (so notifications are serialized) and copy the | |
41 | * notification data. After scheduling the work, we rearm the read from | |
42 | * the notification endpoint. | |
43 | * | |
44 | * Entry points here are: | |
45 | * | |
46 | * wa_nep_[create|destroy]() To initialize/release this subsystem | |
47 | * | |
48 | * wa_nep_cb() Callback for the notification | |
49 | * endpoint; when data is ready, this | |
50 | * does the dispatching. | |
51 | */ | |
52 | #include <linux/workqueue.h> | |
53 | #include <linux/ctype.h> | |
e43ace89 | 54 | |
df365423 IPG |
55 | #include "wa-hc.h" |
56 | #include "wusbhc.h" | |
57 | ||
58 | /* Structure for queueing notifications to the workqueue */ | |
59 | struct wa_notif_work { | |
60 | struct work_struct work; | |
61 | struct wahc *wa; | |
62 | size_t size; | |
63 | u8 data[]; | |
64 | }; | |
65 | ||
66 | /* | |
67 | * Process incoming notifications from the WA's Notification EndPoint | |
68 | * [the wuswad daemon, basically] | |
69 | * | |
70 | * @_nw: Pointer to a descriptor which has the pointer to the | |
71 | * @wa, the size of the buffer and the work queue | |
72 | * structure (so we can free all when done). | |
73 | * @returns 0 if ok, < 0 errno code on error. | |
74 | * | |
75 | * All notifications follow the same format; they need to start with a | |
76 | * 'struct wa_notif_hdr' header, so it is easy to parse through | |
77 | * them. We just break the buffer in individual notifications (the | |
78 | * standard doesn't say if it can be done or is forbidden, so we are | |
79 | * cautious) and dispatch each. | |
80 | * | |
81 | * So the handling layers are is: | |
82 | * | |
83 | * WA specific notification (from NEP) | |
84 | * Device Notification Received -> wa_handle_notif_dn() | |
85 | * WUSB Device notification generic handling | |
86 | * BPST Adjustment -> wa_handle_notif_bpst_adj() | |
87 | * ... -> ... | |
88 | * | |
89 | * @wa has to be referenced | |
90 | */ | |
91 | static void wa_notif_dispatch(struct work_struct *ws) | |
92 | { | |
93 | void *itr; | |
94 | u8 missing = 0; | |
95 | struct wa_notif_work *nw = container_of(ws, struct wa_notif_work, work); | |
96 | struct wahc *wa = nw->wa; | |
97 | struct wa_notif_hdr *notif_hdr; | |
98 | size_t size; | |
99 | ||
100 | struct device *dev = &wa->usb_iface->dev; | |
101 | ||
102 | #if 0 | |
103 | /* FIXME: need to check for this??? */ | |
104 | if (usb_hcd->state == HC_STATE_QUIESCING) /* Going down? */ | |
105 | goto out; /* screw it */ | |
106 | #endif | |
107 | atomic_dec(&wa->notifs_queued); /* Throttling ctl */ | |
108 | dev = &wa->usb_iface->dev; | |
109 | size = nw->size; | |
110 | itr = nw->data; | |
111 | ||
112 | while (size) { | |
113 | if (size < sizeof(*notif_hdr)) { | |
114 | missing = sizeof(*notif_hdr) - size; | |
115 | goto exhausted_buffer; | |
116 | } | |
117 | notif_hdr = itr; | |
118 | if (size < notif_hdr->bLength) | |
119 | goto exhausted_buffer; | |
120 | itr += notif_hdr->bLength; | |
121 | size -= notif_hdr->bLength; | |
122 | /* Dispatch the notification [don't use itr or size!] */ | |
123 | switch (notif_hdr->bNotifyType) { | |
124 | case HWA_NOTIF_DN: { | |
125 | struct hwa_notif_dn *hwa_dn; | |
126 | hwa_dn = container_of(notif_hdr, struct hwa_notif_dn, | |
127 | hdr); | |
128 | wusbhc_handle_dn(wa->wusb, hwa_dn->bSourceDeviceAddr, | |
129 | hwa_dn->dndata, | |
130 | notif_hdr->bLength - sizeof(*hwa_dn)); | |
131 | break; | |
132 | } | |
133 | case WA_NOTIF_TRANSFER: | |
134 | wa_handle_notif_xfer(wa, notif_hdr); | |
135 | break; | |
136 | case DWA_NOTIF_RWAKE: | |
137 | case DWA_NOTIF_PORTSTATUS: | |
138 | case HWA_NOTIF_BPST_ADJ: | |
139 | /* FIXME: unimplemented WA NOTIFs */ | |
140 | /* fallthru */ | |
141 | default: | |
e43ace89 DV |
142 | dev_err(dev, "HWA: unknown notification 0x%x, " |
143 | "%zu bytes; discarding\n", | |
144 | notif_hdr->bNotifyType, | |
145 | (size_t)notif_hdr->bLength); | |
df365423 IPG |
146 | break; |
147 | } | |
148 | } | |
149 | out: | |
150 | wa_put(wa); | |
151 | kfree(nw); | |
152 | return; | |
153 | ||
154 | /* THIS SHOULD NOT HAPPEN | |
155 | * | |
156 | * Buffer exahusted with partial data remaining; just warn and | |
157 | * discard the data, as this should not happen. | |
158 | */ | |
159 | exhausted_buffer: | |
df365423 IPG |
160 | dev_warn(dev, "HWA: device sent short notification, " |
161 | "%d bytes missing; discarding %d bytes.\n", | |
162 | missing, (int)size); | |
df365423 IPG |
163 | goto out; |
164 | } | |
165 | ||
166 | /* | |
167 | * Deliver incoming WA notifications to the wusbwa workqueue | |
168 | * | |
169 | * @wa: Pointer the Wire Adapter Controller Data Streaming | |
170 | * instance (part of an 'struct usb_hcd'). | |
171 | * @size: Size of the received buffer | |
172 | * @returns 0 if ok, < 0 errno code on error. | |
173 | * | |
174 | * The input buffer is @wa->nep_buffer, with @size bytes | |
175 | * (guaranteed to fit in the allocated space, | |
176 | * @wa->nep_buffer_size). | |
177 | */ | |
178 | static int wa_nep_queue(struct wahc *wa, size_t size) | |
179 | { | |
180 | int result = 0; | |
181 | struct device *dev = &wa->usb_iface->dev; | |
182 | struct wa_notif_work *nw; | |
183 | ||
184 | /* dev_fnstart(dev, "(wa %p, size %zu)\n", wa, size); */ | |
185 | BUG_ON(size > wa->nep_buffer_size); | |
186 | if (size == 0) | |
187 | goto out; | |
188 | if (atomic_read(&wa->notifs_queued) > 200) { | |
189 | if (printk_ratelimit()) | |
190 | dev_err(dev, "Too many notifications queued, " | |
191 | "throttling back\n"); | |
192 | goto out; | |
193 | } | |
194 | nw = kzalloc(sizeof(*nw) + size, GFP_ATOMIC); | |
195 | if (nw == NULL) { | |
196 | if (printk_ratelimit()) | |
197 | dev_err(dev, "No memory to queue notification\n"); | |
198 | goto out; | |
199 | } | |
200 | INIT_WORK(&nw->work, wa_notif_dispatch); | |
201 | nw->wa = wa_get(wa); | |
202 | nw->size = size; | |
203 | memcpy(nw->data, wa->nep_buffer, size); | |
204 | atomic_inc(&wa->notifs_queued); /* Throttling ctl */ | |
205 | queue_work(wusbd, &nw->work); | |
206 | out: | |
207 | /* dev_fnend(dev, "(wa %p, size %zu) = result\n", wa, size, result); */ | |
208 | return result; | |
209 | } | |
210 | ||
211 | /* | |
212 | * Callback for the notification event endpoint | |
213 | * | |
214 | * Check's that everything is fine and then passes the data to be | |
215 | * queued to the workqueue. | |
216 | */ | |
217 | static void wa_nep_cb(struct urb *urb) | |
218 | { | |
219 | int result; | |
220 | struct wahc *wa = urb->context; | |
221 | struct device *dev = &wa->usb_iface->dev; | |
222 | ||
223 | switch (result = urb->status) { | |
224 | case 0: | |
225 | result = wa_nep_queue(wa, urb->actual_length); | |
226 | if (result < 0) | |
227 | dev_err(dev, "NEP: unable to process notification(s): " | |
228 | "%d\n", result); | |
229 | break; | |
230 | case -ECONNRESET: /* Not an error, but a controlled situation; */ | |
231 | case -ENOENT: /* (we killed the URB)...so, no broadcast */ | |
232 | case -ESHUTDOWN: | |
233 | dev_dbg(dev, "NEP: going down %d\n", urb->status); | |
234 | goto out; | |
235 | default: /* On general errors, we retry unless it gets ugly */ | |
236 | if (edc_inc(&wa->nep_edc, EDC_MAX_ERRORS, | |
237 | EDC_ERROR_TIMEFRAME)) { | |
238 | dev_err(dev, "NEP: URB max acceptable errors " | |
239 | "exceeded, resetting device\n"); | |
240 | wa_reset_all(wa); | |
241 | goto out; | |
242 | } | |
243 | dev_err(dev, "NEP: URB error %d\n", urb->status); | |
244 | } | |
245 | result = wa_nep_arm(wa, GFP_ATOMIC); | |
246 | if (result < 0) { | |
247 | dev_err(dev, "NEP: cannot submit URB: %d\n", result); | |
248 | wa_reset_all(wa); | |
249 | } | |
250 | out: | |
251 | return; | |
252 | } | |
253 | ||
254 | /* | |
255 | * Initialize @wa's notification and event's endpoint stuff | |
256 | * | |
257 | * This includes the allocating the read buffer, the context ID | |
258 | * allocation bitmap, the URB and submitting the URB. | |
259 | */ | |
260 | int wa_nep_create(struct wahc *wa, struct usb_interface *iface) | |
261 | { | |
262 | int result; | |
263 | struct usb_endpoint_descriptor *epd; | |
264 | struct usb_device *usb_dev = interface_to_usbdev(iface); | |
265 | struct device *dev = &iface->dev; | |
266 | ||
267 | edc_init(&wa->nep_edc); | |
268 | epd = &iface->cur_altsetting->endpoint[0].desc; | |
269 | wa->nep_buffer_size = 1024; | |
270 | wa->nep_buffer = kmalloc(wa->nep_buffer_size, GFP_KERNEL); | |
271 | if (wa->nep_buffer == NULL) { | |
272 | dev_err(dev, "Unable to allocate notification's read buffer\n"); | |
273 | goto error_nep_buffer; | |
274 | } | |
275 | wa->nep_urb = usb_alloc_urb(0, GFP_KERNEL); | |
276 | if (wa->nep_urb == NULL) { | |
277 | dev_err(dev, "Unable to allocate notification URB\n"); | |
278 | goto error_urb_alloc; | |
279 | } | |
280 | usb_fill_int_urb(wa->nep_urb, usb_dev, | |
281 | usb_rcvintpipe(usb_dev, epd->bEndpointAddress), | |
282 | wa->nep_buffer, wa->nep_buffer_size, | |
283 | wa_nep_cb, wa, epd->bInterval); | |
284 | result = wa_nep_arm(wa, GFP_KERNEL); | |
285 | if (result < 0) { | |
286 | dev_err(dev, "Cannot submit notification URB: %d\n", result); | |
287 | goto error_nep_arm; | |
288 | } | |
289 | return 0; | |
290 | ||
291 | error_nep_arm: | |
292 | usb_free_urb(wa->nep_urb); | |
293 | error_urb_alloc: | |
294 | kfree(wa->nep_buffer); | |
295 | error_nep_buffer: | |
296 | return -ENOMEM; | |
297 | } | |
298 | ||
299 | void wa_nep_destroy(struct wahc *wa) | |
300 | { | |
301 | wa_nep_disarm(wa); | |
302 | usb_free_urb(wa->nep_urb); | |
303 | kfree(wa->nep_buffer); | |
304 | } |