2 * Wireless Host Controller: Radio Control Interface (WHCI v0.95[2.3])
3 * Radio Control command/event transport to the UWB stack
5 * Copyright (C) 2005-2006 Intel Corporation
6 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
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.
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.
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
23 * Initialize and hook up the Radio Control interface.
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.
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.
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
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).
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 #include "uwb-internal.h"
54 #include <linux/uwb/debug.h>
57 * Descriptor for an instance of the UWB Radio Control Driver that
58 * attaches to the URC interface of the WHCI PCI card.
60 * Unless there is a lock specific to the 'data members', all access
61 * is protected by uwb_rc->mutex.
64 struct umc_dev *umc_dev;
65 struct uwb_rc *uwb_rc; /* UWB host controller */
68 void __iomem *rc_base;
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;
79 * Execute an UWB RC command on WHCI/RC
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.
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.
90 * NOTE: rc's mutex has to be locked
92 static int whcrc_cmd(struct uwb_rc *uwb_rc,
93 const struct uwb_rccb *cmd, size_t cmd_size)
96 struct whcrc *whcrc = uwb_rc->priv;
97 struct device *dev = &whcrc->umc_dev->dev;
100 d_fnstart(3, dev, "(%p, %p, %zu)\n", uwb_rc, cmd, cmd_size);
103 if (cmd_size >= 4096) {
109 * If the URC is halted, then the hardware has reset itself.
110 * Attempt to recover by restarting the device and then return
111 * an error as it's likely that the current command isn't
112 * valid for a newly started RC.
114 if (le_readl(whcrc->rc_base + URCSTS) & URCSTS_HALTED) {
115 dev_err(dev, "requesting reset of halted radio controller\n");
116 uwb_rc_reset_all(uwb_rc);
121 result = wait_event_timeout(whcrc->cmd_wq,
122 !(le_readl(whcrc->rc_base + URCCMD) & URCCMD_ACTIVE), HZ/2);
124 dev_err(dev, "device is not ready to execute commands\n");
129 memmove(whcrc->cmd_buf, cmd, cmd_size);
130 le_writeq(whcrc->cmd_dma_buf, whcrc->rc_base + URCCMDADDR);
132 spin_lock(&whcrc->irq_lock);
133 urccmd = le_readl(whcrc->rc_base + URCCMD);
134 urccmd &= ~(URCCMD_EARV | URCCMD_SIZE_MASK);
135 le_writel(urccmd | URCCMD_ACTIVE | URCCMD_IWR | cmd_size,
136 whcrc->rc_base + URCCMD);
137 spin_unlock(&whcrc->irq_lock);
140 d_fnend(3, dev, "(%p, %p, %zu) = %d\n",
141 uwb_rc, cmd, cmd_size, result);
145 static int whcrc_reset(struct uwb_rc *rc)
147 struct whcrc *whcrc = rc->priv;
149 return umc_controller_reset(whcrc->umc_dev);
153 * Reset event reception mechanism and tell hw we are ready to get more
155 * We have read all the events in the event buffer, so we are ready to
156 * reset it to the beginning.
158 * This is only called during initialization or after an event buffer
159 * has been retired. This means we can be sure that event processing
160 * is disabled and it's safe to update the URCEVTADDR register.
162 * There's no need to wait for the event processing to start as the
163 * URC will not clear URCCMD_ACTIVE until (internal) event buffer
164 * space is available.
167 void whcrc_enable_events(struct whcrc *whcrc)
169 struct device *dev = &whcrc->umc_dev->dev;
172 d_fnstart(4, dev, "(whcrc %p)\n", whcrc);
174 le_writeq(whcrc->evt_dma_buf, whcrc->rc_base + URCEVTADDR);
176 spin_lock(&whcrc->irq_lock);
177 urccmd = le_readl(whcrc->rc_base + URCCMD) & ~URCCMD_ACTIVE;
178 le_writel(urccmd | URCCMD_EARV, whcrc->rc_base + URCCMD);
179 spin_unlock(&whcrc->irq_lock);
181 d_fnend(4, dev, "(whcrc %p) = void\n", whcrc);
184 static void whcrc_event_work(struct work_struct *work)
186 struct whcrc *whcrc = container_of(work, struct whcrc, event_work);
187 struct device *dev = &whcrc->umc_dev->dev;
191 urcevtaddr = le_readq(whcrc->rc_base + URCEVTADDR);
192 size = urcevtaddr & URCEVTADDR_OFFSET_MASK;
194 d_printf(3, dev, "received %zu octet event\n", size);
195 d_dump(4, dev, whcrc->evt_buf, size > 32 ? 32 : size);
197 uwb_rc_neh_grok(whcrc->uwb_rc, whcrc->evt_buf, size);
198 whcrc_enable_events(whcrc);
204 * We ack inmediately (and expect the hw to do the right thing and
205 * raise another IRQ if things have changed :)
208 irqreturn_t whcrc_irq_cb(int irq, void *_whcrc)
210 struct whcrc *whcrc = _whcrc;
211 struct device *dev = &whcrc->umc_dev->dev;
214 urcsts = le_readl(whcrc->rc_base + URCSTS);
215 if (!(urcsts & URCSTS_INT_MASK))
217 le_writel(urcsts & URCSTS_INT_MASK, whcrc->rc_base + URCSTS);
219 d_printf(4, dev, "acked 0x%08x, urcsts 0x%08x\n",
220 le_readl(whcrc->rc_base + URCSTS), urcsts);
222 if (urcsts & URCSTS_HSE) {
223 dev_err(dev, "host system error -- hardware halted\n");
224 /* FIXME: do something sensible here */
227 if (urcsts & URCSTS_ER) {
228 d_printf(3, dev, "ER: event ready\n");
229 schedule_work(&whcrc->event_work);
231 if (urcsts & URCSTS_RCI) {
232 d_printf(3, dev, "RCI: ready to execute another command\n");
233 wake_up_all(&whcrc->cmd_wq);
241 * Initialize a UMC RC interface: map regions, get (shared) IRQ
244 int whcrc_setup_rc_umc(struct whcrc *whcrc)
247 struct device *dev = &whcrc->umc_dev->dev;
248 struct umc_dev *umc_dev = whcrc->umc_dev;
250 whcrc->area = umc_dev->resource.start;
251 whcrc->rc_len = umc_dev->resource.end - umc_dev->resource.start + 1;
253 if (request_mem_region(whcrc->area, whcrc->rc_len, KBUILD_MODNAME)
255 dev_err(dev, "can't request URC region (%zu bytes @ 0x%lx): %d\n",
256 whcrc->rc_len, whcrc->area, result);
257 goto error_request_region;
260 whcrc->rc_base = ioremap_nocache(whcrc->area, whcrc->rc_len);
261 if (whcrc->rc_base == NULL) {
262 dev_err(dev, "can't ioremap registers (%zu bytes @ 0x%lx): %d\n",
263 whcrc->rc_len, whcrc->area, result);
264 goto error_ioremap_nocache;
267 result = request_irq(umc_dev->irq, whcrc_irq_cb, IRQF_SHARED,
268 KBUILD_MODNAME, whcrc);
270 dev_err(dev, "can't allocate IRQ %d: %d\n",
271 umc_dev->irq, result);
272 goto error_request_irq;
276 whcrc->cmd_buf = dma_alloc_coherent(&umc_dev->dev, PAGE_SIZE,
277 &whcrc->cmd_dma_buf, GFP_KERNEL);
278 if (whcrc->cmd_buf == NULL) {
279 dev_err(dev, "Can't allocate cmd transfer buffer\n");
280 goto error_cmd_buffer;
283 whcrc->evt_buf = dma_alloc_coherent(&umc_dev->dev, PAGE_SIZE,
284 &whcrc->evt_dma_buf, GFP_KERNEL);
285 if (whcrc->evt_buf == NULL) {
286 dev_err(dev, "Can't allocate evt transfer buffer\n");
287 goto error_evt_buffer;
289 d_printf(3, dev, "UWB RC Interface: %zu bytes at 0x%p, irq %u\n",
290 whcrc->rc_len, whcrc->rc_base, umc_dev->irq);
294 dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->cmd_buf,
297 free_irq(umc_dev->irq, whcrc);
299 iounmap(whcrc->rc_base);
300 error_ioremap_nocache:
301 release_mem_region(whcrc->area, whcrc->rc_len);
302 error_request_region:
308 * Release RC's UMC resources
311 void whcrc_release_rc_umc(struct whcrc *whcrc)
313 struct umc_dev *umc_dev = whcrc->umc_dev;
315 dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->evt_buf,
317 dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->cmd_buf,
319 free_irq(umc_dev->irq, whcrc);
320 iounmap(whcrc->rc_base);
321 release_mem_region(whcrc->area, whcrc->rc_len);
326 * whcrc_start_rc - start a WHCI radio controller
327 * @whcrc: the radio controller to start
329 * Reset the UMC device, start the radio controller, enable events and
330 * finally enable interrupts.
332 static int whcrc_start_rc(struct uwb_rc *rc)
334 struct whcrc *whcrc = rc->priv;
336 struct device *dev = &whcrc->umc_dev->dev;
337 unsigned long start, duration;
339 /* Reset the thing */
340 le_writel(URCCMD_RESET, whcrc->rc_base + URCCMD);
343 if (whci_wait_for(dev, whcrc->rc_base + URCCMD, URCCMD_RESET, 0,
344 5000, "device to reset at init") < 0) {
347 } else if (d_test(3)) {
348 duration = jiffies - start;
349 if (duration > msecs_to_jiffies(40))
350 dev_err(dev, "Device took %ums to "
351 "reset. MAX expected: 40ms\n",
352 jiffies_to_msecs(duration));
355 /* Set the event buffer, start the controller (enable IRQs later) */
356 le_writel(0, whcrc->rc_base + URCINTR);
357 le_writel(URCCMD_RS, whcrc->rc_base + URCCMD);
361 if (whci_wait_for(dev, whcrc->rc_base + URCSTS, URCSTS_HALTED, 0,
362 5000, "device to start") < 0)
365 duration = jiffies - start;
366 if (duration > msecs_to_jiffies(40))
367 dev_err(dev, "Device took %ums to start. "
368 "MAX expected: 40ms\n",
369 jiffies_to_msecs(duration));
371 whcrc_enable_events(whcrc);
373 le_writel(URCINTR_EN_ALL, whcrc->rc_base + URCINTR);
380 * whcrc_stop_rc - stop a WHCI radio controller
381 * @whcrc: the radio controller to stop
383 * Disable interrupts and cancel any pending event processing work
384 * before clearing the Run/Stop bit.
387 void whcrc_stop_rc(struct uwb_rc *rc)
389 struct whcrc *whcrc = rc->priv;
390 struct umc_dev *umc_dev = whcrc->umc_dev;
392 le_writel(0, whcrc->rc_base + URCINTR);
393 cancel_work_sync(&whcrc->event_work);
395 le_writel(0, whcrc->rc_base + URCCMD);
396 whci_wait_for(&umc_dev->dev, whcrc->rc_base + URCSTS,
397 URCSTS_HALTED, URCSTS_HALTED, 100, "URCSTS.HALTED");
400 static void whcrc_init(struct whcrc *whcrc)
402 spin_lock_init(&whcrc->irq_lock);
403 init_waitqueue_head(&whcrc->cmd_wq);
404 INIT_WORK(&whcrc->event_work, whcrc_event_work);
408 * Initialize the radio controller.
410 * NOTE: we setup whcrc->uwb_rc before calling uwb_rc_add(); in the
411 * IRQ handler we use that to determine if the hw is ready to
412 * handle events. Looks like a race condition, but it really is
416 int whcrc_probe(struct umc_dev *umc_dev)
419 struct uwb_rc *uwb_rc;
421 struct device *dev = &umc_dev->dev;
423 d_fnstart(3, dev, "(umc_dev %p)\n", umc_dev);
425 uwb_rc = uwb_rc_alloc();
426 if (uwb_rc == NULL) {
427 dev_err(dev, "unable to allocate RC instance\n");
430 whcrc = kzalloc(sizeof(*whcrc), GFP_KERNEL);
432 dev_err(dev, "unable to allocate WHC-RC instance\n");
436 whcrc->umc_dev = umc_dev;
438 result = whcrc_setup_rc_umc(whcrc);
440 dev_err(dev, "Can't setup RC UMC interface: %d\n", result);
441 goto error_setup_rc_umc;
443 whcrc->uwb_rc = uwb_rc;
445 uwb_rc->owner = THIS_MODULE;
446 uwb_rc->cmd = whcrc_cmd;
447 uwb_rc->reset = whcrc_reset;
448 uwb_rc->start = whcrc_start_rc;
449 uwb_rc->stop = whcrc_stop_rc;
451 result = uwb_rc_add(uwb_rc, dev, whcrc);
454 umc_set_drvdata(umc_dev, whcrc);
455 d_fnend(3, dev, "(umc_dev %p) = 0\n", umc_dev);
459 whcrc_release_rc_umc(whcrc);
465 d_fnend(3, dev, "(umc_dev %p) = %d\n", umc_dev, result);
470 * Clean up the radio control resources
472 * When we up the command semaphore, everybody possibly held trying to
473 * execute a command should be granted entry and then they'll see the
474 * host is quiescing and up it (so it will chain to the next waiter).
475 * This should not happen (in any case), as we can only remove when
476 * there are no handles open...
478 static void whcrc_remove(struct umc_dev *umc_dev)
480 struct whcrc *whcrc = umc_get_drvdata(umc_dev);
481 struct uwb_rc *uwb_rc = whcrc->uwb_rc;
483 umc_set_drvdata(umc_dev, NULL);
485 whcrc_release_rc_umc(whcrc);
488 d_printf(1, &umc_dev->dev, "freed whcrc %p\n", whcrc);
491 static int whcrc_pre_reset(struct umc_dev *umc)
493 struct whcrc *whcrc = umc_get_drvdata(umc);
494 struct uwb_rc *uwb_rc = whcrc->uwb_rc;
496 uwb_rc_pre_reset(uwb_rc);
500 static int whcrc_post_reset(struct umc_dev *umc)
502 struct whcrc *whcrc = umc_get_drvdata(umc);
503 struct uwb_rc *uwb_rc = whcrc->uwb_rc;
505 uwb_rc_post_reset(uwb_rc);
509 /* PCI device ID's that we handle [so it gets loaded] */
510 static struct pci_device_id whcrc_id_table[] = {
511 { PCI_DEVICE_CLASS(PCI_CLASS_WIRELESS_WHCI, ~0) },
512 { /* empty last entry */ }
514 MODULE_DEVICE_TABLE(pci, whcrc_id_table);
516 static struct umc_driver whcrc_driver = {
518 .cap_id = UMC_CAP_ID_WHCI_RC,
519 .probe = whcrc_probe,
520 .remove = whcrc_remove,
521 .pre_reset = whcrc_pre_reset,
522 .post_reset = whcrc_post_reset,
525 static int __init whcrc_driver_init(void)
527 return umc_driver_register(&whcrc_driver);
529 module_init(whcrc_driver_init);
531 static void __exit whcrc_driver_exit(void)
533 umc_driver_unregister(&whcrc_driver);
535 module_exit(whcrc_driver_exit);
537 MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
538 MODULE_DESCRIPTION("Wireless Host Controller Radio Control Driver");
539 MODULE_LICENSE("GPL");