1 /*
2 * HWA Host Controller Driver
3 * Wire Adapter Control/Data Streaming Iface (WUSB1.0[8])
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 * This driver implements a USB Host Controller (struct usb_hcd) for a
24 * Wireless USB Host Controller based on the Wireless USB 1.0
25 * Host-Wire-Adapter specification (in layman terms, a USB-dongle that
26 * implements a Wireless USB host).
27 *
28 * Check out the Design-overview.txt file in the source documentation
29 * for other details on the implementation.
30 *
31 * Main blocks:
32 *
33 * driver glue with the driver API, workqueue daemon
34 *
35 * lc RC instance life cycle management (create, destroy...)
36 *
37 * hcd glue with the USB API Host Controller Interface API.
38 *
39 * nep Notification EndPoint managent: collect notifications
40 * and queue them with the workqueue daemon.
41 *
42 * Handle notifications as coming from the NEP. Sends them
43 * off others to their respective modules (eg: connect,
44 * disconnect and reset go to devconnect).
45 *
46 * rpipe Remote Pipe management; rpipe is what we use to write
47 * to an endpoint on a WUSB device that is connected to a
48 * HWA RC.
49 *
50 * xfer Transfer management -- this is all the code that gets a
51 * buffer and pushes it to a device (or viceversa). *
52 *
53 * Some day a lot of this code will be shared between this driver and
54 * the drivers for DWA (xfer, rpipe).
55 *
56 * All starts at driver.c:hwahc_probe(), when one of this guys is
57 * connected. hwahc_disconnect() stops it.
58 *
59 * During operation, the main driver is devices connecting or
60 * disconnecting. They cause the HWA RC to send notifications into
61 * nep.c:hwahc_nep_cb() that will dispatch them to
62 * notif.c:wa_notif_dispatch(). From there they will fan to cause
63 * device connects, disconnects, etc.
64 *
65 * Note much of the activity is difficult to follow. For example a
66 * device connect goes to devconnect, which will cause the "fake" root
67 * hub port to show a connect and stop there. Then khubd will notice
68 * and call into the rh.c:hwahc_rc_port_reset() code to authenticate
69 * the device (and this might require user intervention) and enable
70 * the port.
71 *
72 * We also have a timer workqueue going from devconnect.c that
73 * schedules in hwahc_devconnect_create().
74 *
75 * The rest of the traffic is in the usual entry points of a USB HCD,
76 * which are hooked up in driver.c:hwahc_rc_driver, and defined in
77 * hcd.c.
78 */
79
80 #ifndef __HWAHC_INTERNAL_H__
81 #define __HWAHC_INTERNAL_H__
82
83 #include <linux/completion.h>
84 #include <linux/usb.h>
85 #include <linux/mutex.h>
86 #include <linux/spinlock.h>
87 #include <linux/uwb.h>
88 #include <linux/usb/wusb.h>
89 #include <linux/usb/wusb-wa.h>
90
91 struct wusbhc;
92 struct wahc;
93 extern void wa_urb_enqueue_run(struct work_struct *ws);
94
95 /**
96 * RPipe instance
97 *
98 * @descr's fields are kept in LE, as we need to send it back and
99 * forth.
100 *
101 * @wa is referenced when set
102 *
103 * @segs_available is the number of requests segments that still can
104 * be submitted to the controller without overloading
105 * it. It is initialized to descr->wRequests when
106 * aiming.
107 *
108 * A rpipe supports a max of descr->wRequests at the same time; before
109 * submitting seg_lock has to be taken. If segs_avail > 0, then we can
110 * submit; if not, we have to queue them.
111 */
112 struct wa_rpipe {
113 struct kref refcnt;
114 struct usb_rpipe_descriptor descr;
115 struct usb_host_endpoint *ep;
116 struct wahc *wa;
117 spinlock_t seg_lock;
118 struct list_head seg_list;
119 atomic_t segs_available;
120 u8 buffer[1]; /* For reads/writes on USB */
121 };
122
123
124 /**
125 * Instance of a HWA Host Controller
126 *
127 * Except where a more specific lock/mutex applies or atomic, all
128 * fields protected by @mutex.
129 *
130 * @wa_descr Can be accessed without locking because it is in
131 * the same area where the device descriptors were
132 * read, so it is guaranteed to exist umodified while
133 * the device exists.
134 *
135 * Endianess has been converted to CPU's.
136 *
137 * @nep_* can be accessed without locking as its processing is
138 * serialized; we submit a NEP URB and it comes to
139 * hwahc_nep_cb(), which won't issue another URB until it is
140 * done processing it.
141 *
142 * @xfer_list:
143 *
144 * List of active transfers to verify existence from a xfer id
145 * gotten from the xfer result message. Can't use urb->list because
146 * it goes by endpoint, and we don't know the endpoint at the time
147 * when we get the xfer result message. We can't really rely on the
148 * pointer (will have to change for 64 bits) as the xfer id is 32 bits.
149 *
150 * @xfer_delayed_list: List of transfers that need to be started
151 * (with a workqueue, because they were
152 * submitted from an atomic context).
153 *
154 * FIXME: this needs to be layered up: a wusbhc layer (for sharing
155 * comonalities with WHCI), a wa layer (for sharing
156 * comonalities with DWA-RC).
157 */
158 struct wahc {
159 struct usb_device *usb_dev;
160 struct usb_interface *usb_iface;
161
162 /* HC to deliver notifications */
163 union {
164 struct wusbhc *wusb;
165 struct dwahc *dwa;
166 };
167
168 const struct usb_endpoint_descriptor *dto_epd, *dti_epd;
169 const struct usb_wa_descriptor *wa_descr;
170
171 struct urb *nep_urb; /* Notification EndPoint [lockless] */
172 struct edc nep_edc;
173 void *nep_buffer;
174 size_t nep_buffer_size;
175
176 atomic_t notifs_queued;
177
178 u16 rpipes;
179 unsigned long *rpipe_bm; /* rpipe usage bitmap */
180 spinlock_t rpipe_bm_lock; /* protect rpipe_bm */
181 struct mutex rpipe_mutex; /* assigning resources to endpoints */
182
183 struct urb *dti_urb; /* URB for reading xfer results */
184 struct urb *buf_in_urb; /* URB for reading data in */
185 struct edc dti_edc; /* DTI error density counter */
186 struct wa_xfer_result *xfer_result; /* real size = dti_ep maxpktsize */
187 size_t xfer_result_size;
188
189 s32 status; /* For reading status */
190
191 struct list_head xfer_list;
192 struct list_head xfer_delayed_list;
193 spinlock_t xfer_list_lock;
194 struct work_struct xfer_work;
195 atomic_t xfer_id_count;
196 };
197
198
199 extern int wa_create(struct wahc *wa, struct usb_interface *iface);
200 extern void __wa_destroy(struct wahc *wa);
201 void wa_reset_all(struct wahc *wa);
202
203
204 /* Miscellaneous constants */
205 enum {
206 /** Max number of EPROTO errors we tolerate on the NEP in a
207 * period of time */
208 HWAHC_EPROTO_MAX = 16,
209 /** Period of time for EPROTO errors (in jiffies) */
210 HWAHC_EPROTO_PERIOD = 4 * HZ,
211 };
212
213
214 /* Notification endpoint handling */
215 extern int wa_nep_create(struct wahc *, struct usb_interface *);
216 extern void wa_nep_destroy(struct wahc *);
217
wa_nep_arm(struct wahc * wa,gfp_t gfp_mask)218 static inline int wa_nep_arm(struct wahc *wa, gfp_t gfp_mask)
219 {
220 struct urb *urb = wa->nep_urb;
221 urb->transfer_buffer = wa->nep_buffer;
222 urb->transfer_buffer_length = wa->nep_buffer_size;
223 return usb_submit_urb(urb, gfp_mask);
224 }
225
wa_nep_disarm(struct wahc * wa)226 static inline void wa_nep_disarm(struct wahc *wa)
227 {
228 usb_kill_urb(wa->nep_urb);
229 }
230
231
232 /* RPipes */
wa_rpipe_init(struct wahc * wa)233 static inline void wa_rpipe_init(struct wahc *wa)
234 {
235 spin_lock_init(&wa->rpipe_bm_lock);
236 mutex_init(&wa->rpipe_mutex);
237 }
238
wa_init(struct wahc * wa)239 static inline void wa_init(struct wahc *wa)
240 {
241 edc_init(&wa->nep_edc);
242 atomic_set(&wa->notifs_queued, 0);
243 wa_rpipe_init(wa);
244 edc_init(&wa->dti_edc);
245 INIT_LIST_HEAD(&wa->xfer_list);
246 INIT_LIST_HEAD(&wa->xfer_delayed_list);
247 spin_lock_init(&wa->xfer_list_lock);
248 INIT_WORK(&wa->xfer_work, wa_urb_enqueue_run);
249 atomic_set(&wa->xfer_id_count, 1);
250 }
251
252 /**
253 * Destroy a pipe (when refcount drops to zero)
254 *
255 * Assumes it has been moved to the "QUIESCING" state.
256 */
257 struct wa_xfer;
258 extern void rpipe_destroy(struct kref *_rpipe);
259 static inline
__rpipe_get(struct wa_rpipe * rpipe)260 void __rpipe_get(struct wa_rpipe *rpipe)
261 {
262 kref_get(&rpipe->refcnt);
263 }
264 extern int rpipe_get_by_ep(struct wahc *, struct usb_host_endpoint *,
265 struct urb *, gfp_t);
rpipe_put(struct wa_rpipe * rpipe)266 static inline void rpipe_put(struct wa_rpipe *rpipe)
267 {
268 kref_put(&rpipe->refcnt, rpipe_destroy);
269
270 }
271 extern void rpipe_ep_disable(struct wahc *, struct usb_host_endpoint *);
272 extern int wa_rpipes_create(struct wahc *);
273 extern void wa_rpipes_destroy(struct wahc *);
rpipe_avail_dec(struct wa_rpipe * rpipe)274 static inline void rpipe_avail_dec(struct wa_rpipe *rpipe)
275 {
276 atomic_dec(&rpipe->segs_available);
277 }
278
279 /**
280 * Returns true if the rpipe is ready to submit more segments.
281 */
rpipe_avail_inc(struct wa_rpipe * rpipe)282 static inline int rpipe_avail_inc(struct wa_rpipe *rpipe)
283 {
284 return atomic_inc_return(&rpipe->segs_available) > 0
285 && !list_empty(&rpipe->seg_list);
286 }
287
288
289 /* Transferring data */
290 extern int wa_urb_enqueue(struct wahc *, struct usb_host_endpoint *,
291 struct urb *, gfp_t);
292 extern int wa_urb_dequeue(struct wahc *, struct urb *);
293 extern void wa_handle_notif_xfer(struct wahc *, struct wa_notif_hdr *);
294
295
296 /* Misc
297 *
298 * FIXME: Refcounting for the actual @hwahc object is not correct; I
299 * mean, this should be refcounting on the HCD underneath, but
300 * it is not. In any case, the semantics for HCD refcounting
301 * are *weird*...on refcount reaching zero it just frees
302 * it...no RC specific function is called...unless I miss
303 * something.
304 *
305 * FIXME: has to go away in favour of an 'struct' hcd based sollution
306 */
wa_get(struct wahc * wa)307 static inline struct wahc *wa_get(struct wahc *wa)
308 {
309 usb_get_intf(wa->usb_iface);
310 return wa;
311 }
312
wa_put(struct wahc * wa)313 static inline void wa_put(struct wahc *wa)
314 {
315 usb_put_intf(wa->usb_iface);
316 }
317
318
__wa_feature(struct wahc * wa,unsigned op,u16 feature)319 static inline int __wa_feature(struct wahc *wa, unsigned op, u16 feature)
320 {
321 return usb_control_msg(wa->usb_dev, usb_sndctrlpipe(wa->usb_dev, 0),
322 op ? USB_REQ_SET_FEATURE : USB_REQ_CLEAR_FEATURE,
323 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
324 feature,
325 wa->usb_iface->cur_altsetting->desc.bInterfaceNumber,
326 NULL, 0, 1000 /* FIXME: arbitrary */);
327 }
328
329
__wa_set_feature(struct wahc * wa,u16 feature)330 static inline int __wa_set_feature(struct wahc *wa, u16 feature)
331 {
332 return __wa_feature(wa, 1, feature);
333 }
334
335
__wa_clear_feature(struct wahc * wa,u16 feature)336 static inline int __wa_clear_feature(struct wahc *wa, u16 feature)
337 {
338 return __wa_feature(wa, 0, feature);
339 }
340
341
342 /**
343 * Return the status of a Wire Adapter
344 *
345 * @wa: Wire Adapter instance
346 * @returns < 0 errno code on error, or status bitmap as described
347 * in WUSB1.0[8.3.1.6].
348 *
349 * NOTE: need malloc, some arches don't take USB from the stack
350 */
351 static inline
__wa_get_status(struct wahc * wa)352 s32 __wa_get_status(struct wahc *wa)
353 {
354 s32 result;
355 result = usb_control_msg(
356 wa->usb_dev, usb_rcvctrlpipe(wa->usb_dev, 0),
357 USB_REQ_GET_STATUS,
358 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
359 0, wa->usb_iface->cur_altsetting->desc.bInterfaceNumber,
360 &wa->status, sizeof(wa->status),
361 1000 /* FIXME: arbitrary */);
362 if (result >= 0)
363 result = wa->status;
364 return result;
365 }
366
367
368 /**
369 * Waits until the Wire Adapter's status matches @mask/@value
370 *
371 * @wa: Wire Adapter instance.
372 * @returns < 0 errno code on error, otherwise status.
373 *
374 * Loop until the WAs status matches the mask and value (status & mask
375 * == value). Timeout if it doesn't happen.
376 *
377 * FIXME: is there an official specification on how long status
378 * changes can take?
379 */
__wa_wait_status(struct wahc * wa,u32 mask,u32 value)380 static inline s32 __wa_wait_status(struct wahc *wa, u32 mask, u32 value)
381 {
382 s32 result;
383 unsigned loops = 10;
384 do {
385 msleep(50);
386 result = __wa_get_status(wa);
387 if ((result & mask) == value)
388 break;
389 if (loops-- == 0) {
390 result = -ETIMEDOUT;
391 break;
392 }
393 } while (result >= 0);
394 return result;
395 }
396
397
398 /** Command @hwahc to stop, @returns 0 if ok, < 0 errno code on error */
__wa_stop(struct wahc * wa)399 static inline int __wa_stop(struct wahc *wa)
400 {
401 int result;
402 struct device *dev = &wa->usb_iface->dev;
403
404 result = __wa_clear_feature(wa, WA_ENABLE);
405 if (result < 0 && result != -ENODEV) {
406 dev_err(dev, "error commanding HC to stop: %d\n", result);
407 goto out;
408 }
409 result = __wa_wait_status(wa, WA_ENABLE, 0);
410 if (result < 0 && result != -ENODEV)
411 dev_err(dev, "error waiting for HC to stop: %d\n", result);
412 out:
413 return 0;
414 }
415
416
417 #endif /* #ifndef __HWAHC_INTERNAL_H__ */
418