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/sched.h>
46#include <linux/dma-mapping.h>
47#include <linux/interrupt.h>
48#include <linux/slab.h>
49#include <linux/workqueue.h>
50#include <linux/uwb.h>
51#include <linux/uwb/whci.h>
52#include <linux/uwb/umc.h>
53
54#include "uwb-internal.h"
55
56/**
57 * Descriptor for an instance of the UWB Radio Control Driver that
58 * attaches to the URC interface of the WHCI PCI card.
59 *
60 * Unless there is a lock specific to the 'data members', all access
61 * is protected by uwb_rc->mutex.
62 */
63struct whcrc {
64 struct umc_dev *umc_dev;
65 struct uwb_rc *uwb_rc; /* UWB host controller */
66
67 unsigned long area;
68 void __iomem *rc_base;
69 size_t rc_len;
70 spinlock_t irq_lock;
71
72 void *evt_buf, *cmd_buf;
73 dma_addr_t evt_dma_buf, cmd_dma_buf;
74 wait_queue_head_t cmd_wq;
75 struct work_struct event_work;
76};
77
78/**
79 * Execute an UWB RC command on WHCI/RC
80 *
81 * @rc: Instance of a Radio Controller that is a whcrc
82 * @cmd: Buffer containing the RCCB and payload to execute
83 * @cmd_size: Size of the command buffer.
84 *
85 * We copy the command into whcrc->cmd_buf (as it is pretty and
86 * aligned`and physically contiguous) and then press the right keys in
87 * the controller's URCCMD register to get it to read it. We might
88 * have to wait for the cmd_sem to be open to us.
89 *
90 * NOTE: rc's mutex has to be locked
91 */
92static int whcrc_cmd(struct uwb_rc *uwb_rc,
93 const struct uwb_rccb *cmd, size_t cmd_size)
94{
95 int result = 0;
96 struct whcrc *whcrc = uwb_rc->priv;
97 struct device *dev = &whcrc->umc_dev->dev;
98 u32 urccmd;
99
100 if (cmd_size >= 4096)
101 return -EINVAL;
102
103 /*
104 * If the URC is halted, then the hardware has reset itself.
105 * Attempt to recover by restarting the device and then return
106 * an error as it's likely that the current command isn't
107 * valid for a newly started RC.
108 */
109 if (le_readl(whcrc->rc_base + URCSTS) & URCSTS_HALTED) {
110 dev_err(dev, "requesting reset of halted radio controller\n");
111 uwb_rc_reset_all(uwb_rc);
112 return -EIO;
113 }
114
115 result = wait_event_timeout(whcrc->cmd_wq,
116 !(le_readl(whcrc->rc_base + URCCMD) & URCCMD_ACTIVE), HZ/2);
117 if (result == 0) {
118 dev_err(dev, "device is not ready to execute commands\n");
119 return -ETIMEDOUT;
120 }
121
122 memmove(whcrc->cmd_buf, cmd, cmd_size);
123 le_writeq(whcrc->cmd_dma_buf, whcrc->rc_base + URCCMDADDR);
124
125 spin_lock(&whcrc->irq_lock);
126 urccmd = le_readl(whcrc->rc_base + URCCMD);
127 urccmd &= ~(URCCMD_EARV | URCCMD_SIZE_MASK);
128 le_writel(urccmd | URCCMD_ACTIVE | URCCMD_IWR | cmd_size,
129 whcrc->rc_base + URCCMD);
130 spin_unlock(&whcrc->irq_lock);
131
132 return 0;
133}
134
135static int whcrc_reset(struct uwb_rc *rc)
136{
137 struct whcrc *whcrc = rc->priv;
138
139 return umc_controller_reset(whcrc->umc_dev);
140}
141
142/**
143 * Reset event reception mechanism and tell hw we are ready to get more
144 *
145 * We have read all the events in the event buffer, so we are ready to
146 * reset it to the beginning.
147 *
148 * This is only called during initialization or after an event buffer
149 * has been retired. This means we can be sure that event processing
150 * is disabled and it's safe to update the URCEVTADDR register.
151 *
152 * There's no need to wait for the event processing to start as the
153 * URC will not clear URCCMD_ACTIVE until (internal) event buffer
154 * space is available.
155 */
156static
157void whcrc_enable_events(struct whcrc *whcrc)
158{
159 u32 urccmd;
160
161 le_writeq(whcrc->evt_dma_buf, whcrc->rc_base + URCEVTADDR);
162
163 spin_lock(&whcrc->irq_lock);
164 urccmd = le_readl(whcrc->rc_base + URCCMD) & ~URCCMD_ACTIVE;
165 le_writel(urccmd | URCCMD_EARV, whcrc->rc_base + URCCMD);
166 spin_unlock(&whcrc->irq_lock);
167}
168
169static void whcrc_event_work(struct work_struct *work)
170{
171 struct whcrc *whcrc = container_of(work, struct whcrc, event_work);
172 size_t size;
173 u64 urcevtaddr;
174
175 urcevtaddr = le_readq(whcrc->rc_base + URCEVTADDR);
176 size = urcevtaddr & URCEVTADDR_OFFSET_MASK;
177
178 uwb_rc_neh_grok(whcrc->uwb_rc, whcrc->evt_buf, size);
179 whcrc_enable_events(whcrc);
180}
181
182/**
183 * Catch interrupts?
184 *
185 * We ack inmediately (and expect the hw to do the right thing and
186 * raise another IRQ if things have changed :)
187 */
188static
189irqreturn_t whcrc_irq_cb(int irq, void *_whcrc)
190{
191 struct whcrc *whcrc = _whcrc;
192 struct device *dev = &whcrc->umc_dev->dev;
193 u32 urcsts;
194
195 urcsts = le_readl(whcrc->rc_base + URCSTS);
196 if (!(urcsts & URCSTS_INT_MASK))
197 return IRQ_NONE;
198 le_writel(urcsts & URCSTS_INT_MASK, whcrc->rc_base + URCSTS);
199
200 if (urcsts & URCSTS_HSE) {
201 dev_err(dev, "host system error -- hardware halted\n");
202 /* FIXME: do something sensible here */
203 goto out;
204 }
205 if (urcsts & URCSTS_ER)
206 schedule_work(&whcrc->event_work);
207 if (urcsts & URCSTS_RCI)
208 wake_up_all(&whcrc->cmd_wq);
209out:
210 return IRQ_HANDLED;
211}
212
213
214/**
215 * Initialize a UMC RC interface: map regions, get (shared) IRQ
216 */
217static
218int whcrc_setup_rc_umc(struct whcrc *whcrc)
219{
220 int result = 0;
221 struct device *dev = &whcrc->umc_dev->dev;
222 struct umc_dev *umc_dev = whcrc->umc_dev;
223
224 whcrc->area = umc_dev->resource.start;
225 whcrc->rc_len = resource_size(&umc_dev->resource);
226 result = -EBUSY;
227 if (request_mem_region(whcrc->area, whcrc->rc_len, KBUILD_MODNAME) == NULL) {
228 dev_err(dev, "can't request URC region (%zu bytes @ 0x%lx): %d\n",
229 whcrc->rc_len, whcrc->area, result);
230 goto error_request_region;
231 }
232
233 whcrc->rc_base = ioremap_nocache(whcrc->area, whcrc->rc_len);
234 if (whcrc->rc_base == NULL) {
235 dev_err(dev, "can't ioremap registers (%zu bytes @ 0x%lx): %d\n",
236 whcrc->rc_len, whcrc->area, result);
237 goto error_ioremap_nocache;
238 }
239
240 result = request_irq(umc_dev->irq, whcrc_irq_cb, IRQF_SHARED,
241 KBUILD_MODNAME, whcrc);
242 if (result < 0) {
243 dev_err(dev, "can't allocate IRQ %d: %d\n",
244 umc_dev->irq, result);
245 goto error_request_irq;
246 }
247
248 result = -ENOMEM;
249 whcrc->cmd_buf = dma_alloc_coherent(&umc_dev->dev, PAGE_SIZE,
250 &whcrc->cmd_dma_buf, GFP_KERNEL);
251 if (whcrc->cmd_buf == NULL) {
252 dev_err(dev, "Can't allocate cmd transfer buffer\n");
253 goto error_cmd_buffer;
254 }
255
256 whcrc->evt_buf = dma_alloc_coherent(&umc_dev->dev, PAGE_SIZE,
257 &whcrc->evt_dma_buf, GFP_KERNEL);
258 if (whcrc->evt_buf == NULL) {
259 dev_err(dev, "Can't allocate evt transfer buffer\n");
260 goto error_evt_buffer;
261 }
262 return 0;
263
264error_evt_buffer:
265 dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->cmd_buf,
266 whcrc->cmd_dma_buf);
267error_cmd_buffer:
268 free_irq(umc_dev->irq, whcrc);
269error_request_irq:
270 iounmap(whcrc->rc_base);
271error_ioremap_nocache:
272 release_mem_region(whcrc->area, whcrc->rc_len);
273error_request_region:
274 return result;
275}
276
277
278/**
279 * Release RC's UMC resources
280 */
281static
282void whcrc_release_rc_umc(struct whcrc *whcrc)
283{
284 struct umc_dev *umc_dev = whcrc->umc_dev;
285
286 dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->evt_buf,
287 whcrc->evt_dma_buf);
288 dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->cmd_buf,
289 whcrc->cmd_dma_buf);
290 free_irq(umc_dev->irq, whcrc);
291 iounmap(whcrc->rc_base);
292 release_mem_region(whcrc->area, whcrc->rc_len);
293}
294
295
296/**
297 * whcrc_start_rc - start a WHCI radio controller
298 * @whcrc: the radio controller to start
299 *
300 * Reset the UMC device, start the radio controller, enable events and
301 * finally enable interrupts.
302 */
303static int whcrc_start_rc(struct uwb_rc *rc)
304{
305 struct whcrc *whcrc = rc->priv;
306 struct device *dev = &whcrc->umc_dev->dev;
307
308 /* Reset the thing */
309 le_writel(URCCMD_RESET, whcrc->rc_base + URCCMD);
310 if (whci_wait_for(dev, whcrc->rc_base + URCCMD, URCCMD_RESET, 0,
311 5000, "hardware reset") < 0)
312 return -EBUSY;
313
314 /* Set the event buffer, start the controller (enable IRQs later) */
315 le_writel(0, whcrc->rc_base + URCINTR);
316 le_writel(URCCMD_RS, whcrc->rc_base + URCCMD);
317 if (whci_wait_for(dev, whcrc->rc_base + URCSTS, URCSTS_HALTED, 0,
318 5000, "radio controller start") < 0)
319 return -ETIMEDOUT;
320 whcrc_enable_events(whcrc);
321 le_writel(URCINTR_EN_ALL, whcrc->rc_base + URCINTR);
322 return 0;
323}
324
325
326/**
327 * whcrc_stop_rc - stop a WHCI radio controller
328 * @whcrc: the radio controller to stop
329 *
330 * Disable interrupts and cancel any pending event processing work
331 * before clearing the Run/Stop bit.
332 */
333static
334void whcrc_stop_rc(struct uwb_rc *rc)
335{
336 struct whcrc *whcrc = rc->priv;
337 struct umc_dev *umc_dev = whcrc->umc_dev;
338
339 le_writel(0, whcrc->rc_base + URCINTR);
340 cancel_work_sync(&whcrc->event_work);
341
342 le_writel(0, whcrc->rc_base + URCCMD);
343 whci_wait_for(&umc_dev->dev, whcrc->rc_base + URCSTS,
344 URCSTS_HALTED, URCSTS_HALTED, 100, "radio controller stop");
345}
346
347static void whcrc_init(struct whcrc *whcrc)
348{
349 spin_lock_init(&whcrc->irq_lock);
350 init_waitqueue_head(&whcrc->cmd_wq);
351 INIT_WORK(&whcrc->event_work, whcrc_event_work);
352}
353
354/**
355 * Initialize the radio controller.
356 *
357 * NOTE: we setup whcrc->uwb_rc before calling uwb_rc_add(); in the
358 * IRQ handler we use that to determine if the hw is ready to
359 * handle events. Looks like a race condition, but it really is
360 * not.
361 */
362static
363int whcrc_probe(struct umc_dev *umc_dev)
364{
365 int result;
366 struct uwb_rc *uwb_rc;
367 struct whcrc *whcrc;
368 struct device *dev = &umc_dev->dev;
369
370 result = -ENOMEM;
371 uwb_rc = uwb_rc_alloc();
372 if (uwb_rc == NULL) {
373 dev_err(dev, "unable to allocate RC instance\n");
374 goto error_rc_alloc;
375 }
376 whcrc = kzalloc(sizeof(*whcrc), GFP_KERNEL);
377 if (whcrc == NULL) {
378 dev_err(dev, "unable to allocate WHC-RC instance\n");
379 goto error_alloc;
380 }
381 whcrc_init(whcrc);
382 whcrc->umc_dev = umc_dev;
383
384 result = whcrc_setup_rc_umc(whcrc);
385 if (result < 0) {
386 dev_err(dev, "Can't setup RC UMC interface: %d\n", result);
387 goto error_setup_rc_umc;
388 }
389 whcrc->uwb_rc = uwb_rc;
390
391 uwb_rc->owner = THIS_MODULE;
392 uwb_rc->cmd = whcrc_cmd;
393 uwb_rc->reset = whcrc_reset;
394 uwb_rc->start = whcrc_start_rc;
395 uwb_rc->stop = whcrc_stop_rc;
396
397 result = uwb_rc_add(uwb_rc, dev, whcrc);
398 if (result < 0)
399 goto error_rc_add;
400 umc_set_drvdata(umc_dev, whcrc);
401 return 0;
402
403error_rc_add:
404 whcrc_release_rc_umc(whcrc);
405error_setup_rc_umc:
406 kfree(whcrc);
407error_alloc:
408 uwb_rc_put(uwb_rc);
409error_rc_alloc:
410 return result;
411}
412
413/**
414 * Clean up the radio control resources
415 *
416 * When we up the command semaphore, everybody possibly held trying to
417 * execute a command should be granted entry and then they'll see the
418 * host is quiescing and up it (so it will chain to the next waiter).
419 * This should not happen (in any case), as we can only remove when
420 * there are no handles open...
421 */
422static void whcrc_remove(struct umc_dev *umc_dev)
423{
424 struct whcrc *whcrc = umc_get_drvdata(umc_dev);
425 struct uwb_rc *uwb_rc = whcrc->uwb_rc;
426
427 umc_set_drvdata(umc_dev, NULL);
428 uwb_rc_rm(uwb_rc);
429 whcrc_release_rc_umc(whcrc);
430 kfree(whcrc);
431 uwb_rc_put(uwb_rc);
432}
433
434static int whcrc_pre_reset(struct umc_dev *umc)
435{
436 struct whcrc *whcrc = umc_get_drvdata(umc);
437 struct uwb_rc *uwb_rc = whcrc->uwb_rc;
438
439 uwb_rc_pre_reset(uwb_rc);
440 return 0;
441}
442
443static int whcrc_post_reset(struct umc_dev *umc)
444{
445 struct whcrc *whcrc = umc_get_drvdata(umc);
446 struct uwb_rc *uwb_rc = whcrc->uwb_rc;
447
448 return uwb_rc_post_reset(uwb_rc);
449}
450
451/* PCI device ID's that we handle [so it gets loaded] */
452static struct pci_device_id __used whcrc_id_table[] = {
453 { PCI_DEVICE_CLASS(PCI_CLASS_WIRELESS_WHCI, ~0) },
454 { /* empty last entry */ }
455};
456MODULE_DEVICE_TABLE(pci, whcrc_id_table);
457
458static struct umc_driver whcrc_driver = {
459 .name = "whc-rc",
460 .cap_id = UMC_CAP_ID_WHCI_RC,
461 .probe = whcrc_probe,
462 .remove = whcrc_remove,
463 .pre_reset = whcrc_pre_reset,
464 .post_reset = whcrc_post_reset,
465};
466
467static int __init whcrc_driver_init(void)
468{
469 return umc_driver_register(&whcrc_driver);
470}
471module_init(whcrc_driver_init);
472
473static void __exit whcrc_driver_exit(void)
474{
475 umc_driver_unregister(&whcrc_driver);
476}
477module_exit(whcrc_driver_exit);
478
479MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
480MODULE_DESCRIPTION("Wireless Host Controller Radio Control Driver");
481MODULE_LICENSE("GPL");
482