1 /*
2 * Wireless Host Controller: Radio Control Interface (WHCI v0.95[2.3])
3 * Radio Control command/event transport to the UWB stack
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 * Initialize and hook up the Radio Control interface.
24 *
25 * For each device probed, creates an 'struct whcrc' which contains
26 * just the representation of the UWB Radio Controller, and the logic
27 * for reading notifications and passing them to the UWB Core.
28 *
29 * So we initialize all of those, register the UWB Radio Controller
30 * and setup the notification/event handle to pipe the notifications
31 * to the UWB management Daemon.
32 *
33 * Once uwb_rc_add() is called, the UWB stack takes control, resets
34 * the radio and readies the device to take commands the UWB
35 * API/user-space.
36 *
37 * Note this driver is just a transport driver; the commands are
38 * formed at the UWB stack and given to this driver who will deliver
39 * them to the hw and transfer the replies/notifications back to the
40 * UWB stack through the UWB daemon (UWBD).
41 */
42 #include <linux/init.h>
43 #include <linux/module.h>
44 #include <linux/pci.h>
45 #include <linux/dma-mapping.h>
46 #include <linux/interrupt.h>
47 #include <linux/workqueue.h>
48 #include <linux/uwb.h>
49 #include <linux/uwb/whci.h>
50 #include <linux/uwb/umc.h>
51
52 #include "uwb-internal.h"
53
54 /**
55 * Descriptor for an instance of the UWB Radio Control Driver that
56 * attaches to the URC interface of the WHCI PCI card.
57 *
58 * Unless there is a lock specific to the 'data members', all access
59 * is protected by uwb_rc->mutex.
60 */
61 struct whcrc {
62 struct umc_dev *umc_dev;
63 struct uwb_rc *uwb_rc; /* UWB host controller */
64
65 unsigned long area;
66 void __iomem *rc_base;
67 size_t rc_len;
68 spinlock_t irq_lock;
69
70 void *evt_buf, *cmd_buf;
71 dma_addr_t evt_dma_buf, cmd_dma_buf;
72 wait_queue_head_t cmd_wq;
73 struct work_struct event_work;
74 };
75
76 /**
77 * Execute an UWB RC command on WHCI/RC
78 *
79 * @rc: Instance of a Radio Controller that is a whcrc
80 * @cmd: Buffer containing the RCCB and payload to execute
81 * @cmd_size: Size of the command buffer.
82 *
83 * We copy the command into whcrc->cmd_buf (as it is pretty and
84 * aligned`and physically contiguous) and then press the right keys in
85 * the controller's URCCMD register to get it to read it. We might
86 * have to wait for the cmd_sem to be open to us.
87 *
88 * NOTE: rc's mutex has to be locked
89 */
whcrc_cmd(struct uwb_rc * uwb_rc,const struct uwb_rccb * cmd,size_t cmd_size)90 static int whcrc_cmd(struct uwb_rc *uwb_rc,
91 const struct uwb_rccb *cmd, size_t cmd_size)
92 {
93 int result = 0;
94 struct whcrc *whcrc = uwb_rc->priv;
95 struct device *dev = &whcrc->umc_dev->dev;
96 u32 urccmd;
97
98 if (cmd_size >= 4096)
99 return -EINVAL;
100
101 /*
102 * If the URC is halted, then the hardware has reset itself.
103 * Attempt to recover by restarting the device and then return
104 * an error as it's likely that the current command isn't
105 * valid for a newly started RC.
106 */
107 if (le_readl(whcrc->rc_base + URCSTS) & URCSTS_HALTED) {
108 dev_err(dev, "requesting reset of halted radio controller\n");
109 uwb_rc_reset_all(uwb_rc);
110 return -EIO;
111 }
112
113 result = wait_event_timeout(whcrc->cmd_wq,
114 !(le_readl(whcrc->rc_base + URCCMD) & URCCMD_ACTIVE), HZ/2);
115 if (result == 0) {
116 dev_err(dev, "device is not ready to execute commands\n");
117 return -ETIMEDOUT;
118 }
119
120 memmove(whcrc->cmd_buf, cmd, cmd_size);
121 le_writeq(whcrc->cmd_dma_buf, whcrc->rc_base + URCCMDADDR);
122
123 spin_lock(&whcrc->irq_lock);
124 urccmd = le_readl(whcrc->rc_base + URCCMD);
125 urccmd &= ~(URCCMD_EARV | URCCMD_SIZE_MASK);
126 le_writel(urccmd | URCCMD_ACTIVE | URCCMD_IWR | cmd_size,
127 whcrc->rc_base + URCCMD);
128 spin_unlock(&whcrc->irq_lock);
129
130 return 0;
131 }
132
whcrc_reset(struct uwb_rc * rc)133 static int whcrc_reset(struct uwb_rc *rc)
134 {
135 struct whcrc *whcrc = rc->priv;
136
137 return umc_controller_reset(whcrc->umc_dev);
138 }
139
140 /**
141 * Reset event reception mechanism and tell hw we are ready to get more
142 *
143 * We have read all the events in the event buffer, so we are ready to
144 * reset it to the beginning.
145 *
146 * This is only called during initialization or after an event buffer
147 * has been retired. This means we can be sure that event processing
148 * is disabled and it's safe to update the URCEVTADDR register.
149 *
150 * There's no need to wait for the event processing to start as the
151 * URC will not clear URCCMD_ACTIVE until (internal) event buffer
152 * space is available.
153 */
154 static
whcrc_enable_events(struct whcrc * whcrc)155 void whcrc_enable_events(struct whcrc *whcrc)
156 {
157 u32 urccmd;
158
159 le_writeq(whcrc->evt_dma_buf, whcrc->rc_base + URCEVTADDR);
160
161 spin_lock(&whcrc->irq_lock);
162 urccmd = le_readl(whcrc->rc_base + URCCMD) & ~URCCMD_ACTIVE;
163 le_writel(urccmd | URCCMD_EARV, whcrc->rc_base + URCCMD);
164 spin_unlock(&whcrc->irq_lock);
165 }
166
whcrc_event_work(struct work_struct * work)167 static void whcrc_event_work(struct work_struct *work)
168 {
169 struct whcrc *whcrc = container_of(work, struct whcrc, event_work);
170 size_t size;
171 u64 urcevtaddr;
172
173 urcevtaddr = le_readq(whcrc->rc_base + URCEVTADDR);
174 size = urcevtaddr & URCEVTADDR_OFFSET_MASK;
175
176 uwb_rc_neh_grok(whcrc->uwb_rc, whcrc->evt_buf, size);
177 whcrc_enable_events(whcrc);
178 }
179
180 /**
181 * Catch interrupts?
182 *
183 * We ack inmediately (and expect the hw to do the right thing and
184 * raise another IRQ if things have changed :)
185 */
186 static
whcrc_irq_cb(int irq,void * _whcrc)187 irqreturn_t whcrc_irq_cb(int irq, void *_whcrc)
188 {
189 struct whcrc *whcrc = _whcrc;
190 struct device *dev = &whcrc->umc_dev->dev;
191 u32 urcsts;
192
193 urcsts = le_readl(whcrc->rc_base + URCSTS);
194 if (!(urcsts & URCSTS_INT_MASK))
195 return IRQ_NONE;
196 le_writel(urcsts & URCSTS_INT_MASK, whcrc->rc_base + URCSTS);
197
198 if (urcsts & URCSTS_HSE) {
199 dev_err(dev, "host system error -- hardware halted\n");
200 /* FIXME: do something sensible here */
201 goto out;
202 }
203 if (urcsts & URCSTS_ER)
204 schedule_work(&whcrc->event_work);
205 if (urcsts & URCSTS_RCI)
206 wake_up_all(&whcrc->cmd_wq);
207 out:
208 return IRQ_HANDLED;
209 }
210
211
212 /**
213 * Initialize a UMC RC interface: map regions, get (shared) IRQ
214 */
215 static
whcrc_setup_rc_umc(struct whcrc * whcrc)216 int whcrc_setup_rc_umc(struct whcrc *whcrc)
217 {
218 int result = 0;
219 struct device *dev = &whcrc->umc_dev->dev;
220 struct umc_dev *umc_dev = whcrc->umc_dev;
221
222 whcrc->area = umc_dev->resource.start;
223 whcrc->rc_len = umc_dev->resource.end - umc_dev->resource.start + 1;
224 result = -EBUSY;
225 if (request_mem_region(whcrc->area, whcrc->rc_len, KBUILD_MODNAME) == NULL) {
226 dev_err(dev, "can't request URC region (%zu bytes @ 0x%lx): %d\n",
227 whcrc->rc_len, whcrc->area, result);
228 goto error_request_region;
229 }
230
231 whcrc->rc_base = ioremap_nocache(whcrc->area, whcrc->rc_len);
232 if (whcrc->rc_base == NULL) {
233 dev_err(dev, "can't ioremap registers (%zu bytes @ 0x%lx): %d\n",
234 whcrc->rc_len, whcrc->area, result);
235 goto error_ioremap_nocache;
236 }
237
238 result = request_irq(umc_dev->irq, whcrc_irq_cb, IRQF_SHARED,
239 KBUILD_MODNAME, whcrc);
240 if (result < 0) {
241 dev_err(dev, "can't allocate IRQ %d: %d\n",
242 umc_dev->irq, result);
243 goto error_request_irq;
244 }
245
246 result = -ENOMEM;
247 whcrc->cmd_buf = dma_alloc_coherent(&umc_dev->dev, PAGE_SIZE,
248 &whcrc->cmd_dma_buf, GFP_KERNEL);
249 if (whcrc->cmd_buf == NULL) {
250 dev_err(dev, "Can't allocate cmd transfer buffer\n");
251 goto error_cmd_buffer;
252 }
253
254 whcrc->evt_buf = dma_alloc_coherent(&umc_dev->dev, PAGE_SIZE,
255 &whcrc->evt_dma_buf, GFP_KERNEL);
256 if (whcrc->evt_buf == NULL) {
257 dev_err(dev, "Can't allocate evt transfer buffer\n");
258 goto error_evt_buffer;
259 }
260 return 0;
261
262 error_evt_buffer:
263 dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->cmd_buf,
264 whcrc->cmd_dma_buf);
265 error_cmd_buffer:
266 free_irq(umc_dev->irq, whcrc);
267 error_request_irq:
268 iounmap(whcrc->rc_base);
269 error_ioremap_nocache:
270 release_mem_region(whcrc->area, whcrc->rc_len);
271 error_request_region:
272 return result;
273 }
274
275
276 /**
277 * Release RC's UMC resources
278 */
279 static
whcrc_release_rc_umc(struct whcrc * whcrc)280 void whcrc_release_rc_umc(struct whcrc *whcrc)
281 {
282 struct umc_dev *umc_dev = whcrc->umc_dev;
283
284 dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->evt_buf,
285 whcrc->evt_dma_buf);
286 dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->cmd_buf,
287 whcrc->cmd_dma_buf);
288 free_irq(umc_dev->irq, whcrc);
289 iounmap(whcrc->rc_base);
290 release_mem_region(whcrc->area, whcrc->rc_len);
291 }
292
293
294 /**
295 * whcrc_start_rc - start a WHCI radio controller
296 * @whcrc: the radio controller to start
297 *
298 * Reset the UMC device, start the radio controller, enable events and
299 * finally enable interrupts.
300 */
whcrc_start_rc(struct uwb_rc * rc)301 static int whcrc_start_rc(struct uwb_rc *rc)
302 {
303 struct whcrc *whcrc = rc->priv;
304 struct device *dev = &whcrc->umc_dev->dev;
305
306 /* Reset the thing */
307 le_writel(URCCMD_RESET, whcrc->rc_base + URCCMD);
308 if (whci_wait_for(dev, whcrc->rc_base + URCCMD, URCCMD_RESET, 0,
309 5000, "hardware reset") < 0)
310 return -EBUSY;
311
312 /* Set the event buffer, start the controller (enable IRQs later) */
313 le_writel(0, whcrc->rc_base + URCINTR);
314 le_writel(URCCMD_RS, whcrc->rc_base + URCCMD);
315 if (whci_wait_for(dev, whcrc->rc_base + URCSTS, URCSTS_HALTED, 0,
316 5000, "radio controller start") < 0)
317 return -ETIMEDOUT;
318 whcrc_enable_events(whcrc);
319 le_writel(URCINTR_EN_ALL, whcrc->rc_base + URCINTR);
320 return 0;
321 }
322
323
324 /**
325 * whcrc_stop_rc - stop a WHCI radio controller
326 * @whcrc: the radio controller to stop
327 *
328 * Disable interrupts and cancel any pending event processing work
329 * before clearing the Run/Stop bit.
330 */
331 static
whcrc_stop_rc(struct uwb_rc * rc)332 void whcrc_stop_rc(struct uwb_rc *rc)
333 {
334 struct whcrc *whcrc = rc->priv;
335 struct umc_dev *umc_dev = whcrc->umc_dev;
336
337 le_writel(0, whcrc->rc_base + URCINTR);
338 cancel_work_sync(&whcrc->event_work);
339
340 le_writel(0, whcrc->rc_base + URCCMD);
341 whci_wait_for(&umc_dev->dev, whcrc->rc_base + URCSTS,
342 URCSTS_HALTED, URCSTS_HALTED, 100, "radio controller stop");
343 }
344
whcrc_init(struct whcrc * whcrc)345 static void whcrc_init(struct whcrc *whcrc)
346 {
347 spin_lock_init(&whcrc->irq_lock);
348 init_waitqueue_head(&whcrc->cmd_wq);
349 INIT_WORK(&whcrc->event_work, whcrc_event_work);
350 }
351
352 /**
353 * Initialize the radio controller.
354 *
355 * NOTE: we setup whcrc->uwb_rc before calling uwb_rc_add(); in the
356 * IRQ handler we use that to determine if the hw is ready to
357 * handle events. Looks like a race condition, but it really is
358 * not.
359 */
360 static
whcrc_probe(struct umc_dev * umc_dev)361 int whcrc_probe(struct umc_dev *umc_dev)
362 {
363 int result;
364 struct uwb_rc *uwb_rc;
365 struct whcrc *whcrc;
366 struct device *dev = &umc_dev->dev;
367
368 result = -ENOMEM;
369 uwb_rc = uwb_rc_alloc();
370 if (uwb_rc == NULL) {
371 dev_err(dev, "unable to allocate RC instance\n");
372 goto error_rc_alloc;
373 }
374 whcrc = kzalloc(sizeof(*whcrc), GFP_KERNEL);
375 if (whcrc == NULL) {
376 dev_err(dev, "unable to allocate WHC-RC instance\n");
377 goto error_alloc;
378 }
379 whcrc_init(whcrc);
380 whcrc->umc_dev = umc_dev;
381
382 result = whcrc_setup_rc_umc(whcrc);
383 if (result < 0) {
384 dev_err(dev, "Can't setup RC UMC interface: %d\n", result);
385 goto error_setup_rc_umc;
386 }
387 whcrc->uwb_rc = uwb_rc;
388
389 uwb_rc->owner = THIS_MODULE;
390 uwb_rc->cmd = whcrc_cmd;
391 uwb_rc->reset = whcrc_reset;
392 uwb_rc->start = whcrc_start_rc;
393 uwb_rc->stop = whcrc_stop_rc;
394
395 result = uwb_rc_add(uwb_rc, dev, whcrc);
396 if (result < 0)
397 goto error_rc_add;
398 umc_set_drvdata(umc_dev, whcrc);
399 return 0;
400
401 error_rc_add:
402 whcrc_release_rc_umc(whcrc);
403 error_setup_rc_umc:
404 kfree(whcrc);
405 error_alloc:
406 uwb_rc_put(uwb_rc);
407 error_rc_alloc:
408 return result;
409 }
410
411 /**
412 * Clean up the radio control resources
413 *
414 * When we up the command semaphore, everybody possibly held trying to
415 * execute a command should be granted entry and then they'll see the
416 * host is quiescing and up it (so it will chain to the next waiter).
417 * This should not happen (in any case), as we can only remove when
418 * there are no handles open...
419 */
whcrc_remove(struct umc_dev * umc_dev)420 static void whcrc_remove(struct umc_dev *umc_dev)
421 {
422 struct whcrc *whcrc = umc_get_drvdata(umc_dev);
423 struct uwb_rc *uwb_rc = whcrc->uwb_rc;
424
425 umc_set_drvdata(umc_dev, NULL);
426 uwb_rc_rm(uwb_rc);
427 whcrc_release_rc_umc(whcrc);
428 kfree(whcrc);
429 uwb_rc_put(uwb_rc);
430 }
431
whcrc_pre_reset(struct umc_dev * umc)432 static int whcrc_pre_reset(struct umc_dev *umc)
433 {
434 struct whcrc *whcrc = umc_get_drvdata(umc);
435 struct uwb_rc *uwb_rc = whcrc->uwb_rc;
436
437 uwb_rc_pre_reset(uwb_rc);
438 return 0;
439 }
440
whcrc_post_reset(struct umc_dev * umc)441 static int whcrc_post_reset(struct umc_dev *umc)
442 {
443 struct whcrc *whcrc = umc_get_drvdata(umc);
444 struct uwb_rc *uwb_rc = whcrc->uwb_rc;
445
446 uwb_rc_post_reset(uwb_rc);
447 return 0;
448 }
449
450 /* PCI device ID's that we handle [so it gets loaded] */
451 static struct pci_device_id whcrc_id_table[] = {
452 { PCI_DEVICE_CLASS(PCI_CLASS_WIRELESS_WHCI, ~0) },
453 { /* empty last entry */ }
454 };
455 MODULE_DEVICE_TABLE(pci, whcrc_id_table);
456
457 static struct umc_driver whcrc_driver = {
458 .name = "whc-rc",
459 .cap_id = UMC_CAP_ID_WHCI_RC,
460 .probe = whcrc_probe,
461 .remove = whcrc_remove,
462 .pre_reset = whcrc_pre_reset,
463 .post_reset = whcrc_post_reset,
464 };
465
whcrc_driver_init(void)466 static int __init whcrc_driver_init(void)
467 {
468 return umc_driver_register(&whcrc_driver);
469 }
470 module_init(whcrc_driver_init);
471
whcrc_driver_exit(void)472 static void __exit whcrc_driver_exit(void)
473 {
474 umc_driver_unregister(&whcrc_driver);
475 }
476 module_exit(whcrc_driver_exit);
477
478 MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
479 MODULE_DESCRIPTION("Wireless Host Controller Radio Control Driver");
480 MODULE_LICENSE("GPL");
481