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 goto out; 203 } 204 if (urcsts & URCSTS_ER) 205 schedule_work(&whcrc->event_work); 206 if (urcsts & URCSTS_RCI) 207 wake_up_all(&whcrc->cmd_wq); 208out: 209 return IRQ_HANDLED; 210} 211 212 213/** 214 * Initialize a UMC RC interface: map regions, get (shared) IRQ 215 */ 216static 217int whcrc_setup_rc_umc(struct whcrc *whcrc) 218{ 219 int result = 0; 220 struct device *dev = &whcrc->umc_dev->dev; 221 struct umc_dev *umc_dev = whcrc->umc_dev; 222 223 whcrc->area = umc_dev->resource.start; 224 whcrc->rc_len = umc_dev->resource.end - umc_dev->resource.start + 1; 225 result = -EBUSY; 226 if (request_mem_region(whcrc->area, whcrc->rc_len, KBUILD_MODNAME) == NULL) { 227 dev_err(dev, "can't request URC region (%zu bytes @ 0x%lx): %d\n", 228 whcrc->rc_len, whcrc->area, result); 229 goto error_request_region; 230 } 231 232 whcrc->rc_base = ioremap_nocache(whcrc->area, whcrc->rc_len); 233 if (whcrc->rc_base == NULL) { 234 dev_err(dev, "can't ioremap registers (%zu bytes @ 0x%lx): %d\n", 235 whcrc->rc_len, whcrc->area, result); 236 goto error_ioremap_nocache; 237 } 238 239 result = request_irq(umc_dev->irq, whcrc_irq_cb, IRQF_SHARED, 240 KBUILD_MODNAME, whcrc); 241 if (result < 0) { 242 dev_err(dev, "can't allocate IRQ %d: %d\n", 243 umc_dev->irq, result); 244 goto error_request_irq; 245 } 246 247 result = -ENOMEM; 248 whcrc->cmd_buf = dma_alloc_coherent(&umc_dev->dev, PAGE_SIZE, 249 &whcrc->cmd_dma_buf, GFP_KERNEL); 250 if (whcrc->cmd_buf == NULL) { 251 dev_err(dev, "Can't allocate cmd transfer buffer\n"); 252 goto error_cmd_buffer; 253 } 254 255 whcrc->evt_buf = dma_alloc_coherent(&umc_dev->dev, PAGE_SIZE, 256 &whcrc->evt_dma_buf, GFP_KERNEL); 257 if (whcrc->evt_buf == NULL) { 258 dev_err(dev, "Can't allocate evt transfer buffer\n"); 259 goto error_evt_buffer; 260 } 261 return 0; 262 263error_evt_buffer: 264 dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->cmd_buf, 265 whcrc->cmd_dma_buf); 266error_cmd_buffer: 267 free_irq(umc_dev->irq, whcrc); 268error_request_irq: 269 iounmap(whcrc->rc_base); 270error_ioremap_nocache: 271 release_mem_region(whcrc->area, whcrc->rc_len); 272error_request_region: 273 return result; 274} 275 276 277/** 278 * Release RC's UMC resources 279 */ 280static 281void whcrc_release_rc_umc(struct whcrc *whcrc) 282{ 283 struct umc_dev *umc_dev = whcrc->umc_dev; 284 285 dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->evt_buf, 286 whcrc->evt_dma_buf); 287 dma_free_coherent(&umc_dev->dev, PAGE_SIZE, whcrc->cmd_buf, 288 whcrc->cmd_dma_buf); 289 free_irq(umc_dev->irq, whcrc); 290 iounmap(whcrc->rc_base); 291 release_mem_region(whcrc->area, whcrc->rc_len); 292} 293 294 295/** 296 * whcrc_start_rc - start a WHCI radio controller 297 * @whcrc: the radio controller to start 298 * 299 * Reset the UMC device, start the radio controller, enable events and 300 * finally enable interrupts. 301 */ 302static int whcrc_start_rc(struct uwb_rc *rc) 303{ 304 struct whcrc *whcrc = rc->priv; 305 struct device *dev = &whcrc->umc_dev->dev; 306 307 /* Reset the thing */ 308 le_writel(URCCMD_RESET, whcrc->rc_base + URCCMD); 309 if (whci_wait_for(dev, whcrc->rc_base + URCCMD, URCCMD_RESET, 0, 310 5000, "hardware reset") < 0) 311 return -EBUSY; 312 313 /* Set the event buffer, start the controller (enable IRQs later) */ 314 le_writel(0, whcrc->rc_base + URCINTR); 315 le_writel(URCCMD_RS, whcrc->rc_base + URCCMD); 316 if (whci_wait_for(dev, whcrc->rc_base + URCSTS, URCSTS_HALTED, 0, 317 5000, "radio controller start") < 0) 318 return -ETIMEDOUT; 319 whcrc_enable_events(whcrc); 320 le_writel(URCINTR_EN_ALL, whcrc->rc_base + URCINTR); 321 return 0; 322} 323 324 325/** 326 * whcrc_stop_rc - stop a WHCI radio controller 327 * @whcrc: the radio controller to stop 328 * 329 * Disable interrupts and cancel any pending event processing work 330 * before clearing the Run/Stop bit. 331 */ 332static 333void whcrc_stop_rc(struct uwb_rc *rc) 334{ 335 struct whcrc *whcrc = rc->priv; 336 struct umc_dev *umc_dev = whcrc->umc_dev; 337 338 le_writel(0, whcrc->rc_base + URCINTR); 339 cancel_work_sync(&whcrc->event_work); 340 341 le_writel(0, whcrc->rc_base + URCCMD); 342 whci_wait_for(&umc_dev->dev, whcrc->rc_base + URCSTS, 343 URCSTS_HALTED, URCSTS_HALTED, 100, "radio controller stop"); 344} 345 346static void whcrc_init(struct whcrc *whcrc) 347{ 348 spin_lock_init(&whcrc->irq_lock); 349 init_waitqueue_head(&whcrc->cmd_wq); 350 INIT_WORK(&whcrc->event_work, whcrc_event_work); 351} 352 353/** 354 * Initialize the radio controller. 355 * 356 * NOTE: we setup whcrc->uwb_rc before calling uwb_rc_add(); in the 357 * IRQ handler we use that to determine if the hw is ready to 358 * handle events. Looks like a race condition, but it really is 359 * not. 360 */ 361static 362int whcrc_probe(struct umc_dev *umc_dev) 363{ 364 int result; 365 struct uwb_rc *uwb_rc; 366 struct whcrc *whcrc; 367 struct device *dev = &umc_dev->dev; 368 369 result = -ENOMEM; 370 uwb_rc = uwb_rc_alloc(); 371 if (uwb_rc == NULL) { 372 dev_err(dev, "unable to allocate RC instance\n"); 373 goto error_rc_alloc; 374 } 375 whcrc = kzalloc(sizeof(*whcrc), GFP_KERNEL); 376 if (whcrc == NULL) { 377 dev_err(dev, "unable to allocate WHC-RC instance\n"); 378 goto error_alloc; 379 } 380 whcrc_init(whcrc); 381 whcrc->umc_dev = umc_dev; 382 383 result = whcrc_setup_rc_umc(whcrc); 384 if (result < 0) { 385 dev_err(dev, "Can't setup RC UMC interface: %d\n", result); 386 goto error_setup_rc_umc; 387 } 388 whcrc->uwb_rc = uwb_rc; 389 390 uwb_rc->owner = THIS_MODULE; 391 uwb_rc->cmd = whcrc_cmd; 392 uwb_rc->reset = whcrc_reset; 393 uwb_rc->start = whcrc_start_rc; 394 uwb_rc->stop = whcrc_stop_rc; 395 396 result = uwb_rc_add(uwb_rc, dev, whcrc); 397 if (result < 0) 398 goto error_rc_add; 399 umc_set_drvdata(umc_dev, whcrc); 400 return 0; 401 402error_rc_add: 403 whcrc_release_rc_umc(whcrc); 404error_setup_rc_umc: 405 kfree(whcrc); 406error_alloc: 407 uwb_rc_put(uwb_rc); 408error_rc_alloc: 409 return result; 410} 411 412/** 413 * Clean up the radio control resources 414 * 415 * When we up the command semaphore, everybody possibly held trying to 416 * execute a command should be granted entry and then they'll see the 417 * host is quiescing and up it (so it will chain to the next waiter). 418 * This should not happen (in any case), as we can only remove when 419 * there are no handles open... 420 */ 421static void whcrc_remove(struct umc_dev *umc_dev) 422{ 423 struct whcrc *whcrc = umc_get_drvdata(umc_dev); 424 struct uwb_rc *uwb_rc = whcrc->uwb_rc; 425 426 umc_set_drvdata(umc_dev, NULL); 427 uwb_rc_rm(uwb_rc); 428 whcrc_release_rc_umc(whcrc); 429 kfree(whcrc); 430 uwb_rc_put(uwb_rc); 431} 432 433static int whcrc_pre_reset(struct umc_dev *umc) 434{ 435 struct whcrc *whcrc = umc_get_drvdata(umc); 436 struct uwb_rc *uwb_rc = whcrc->uwb_rc; 437 438 uwb_rc_pre_reset(uwb_rc); 439 return 0; 440} 441 442static int whcrc_post_reset(struct umc_dev *umc) 443{ 444 struct whcrc *whcrc = umc_get_drvdata(umc); 445 struct uwb_rc *uwb_rc = whcrc->uwb_rc; 446 447 return uwb_rc_post_reset(uwb_rc); 448} 449 450/* PCI device ID's that we handle [so it gets loaded] */ 451static struct pci_device_id whcrc_id_table[] = { 452 { PCI_DEVICE_CLASS(PCI_CLASS_WIRELESS_WHCI, ~0) }, 453 { /* empty last entry */ } 454}; 455MODULE_DEVICE_TABLE(pci, whcrc_id_table); 456 457static 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 466static int __init whcrc_driver_init(void) 467{ 468 return umc_driver_register(&whcrc_driver); 469} 470module_init(whcrc_driver_init); 471 472static void __exit whcrc_driver_exit(void) 473{ 474 umc_driver_unregister(&whcrc_driver); 475} 476module_exit(whcrc_driver_exit); 477 478MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>"); 479MODULE_DESCRIPTION("Wireless Host Controller Radio Control Driver"); 480MODULE_LICENSE("GPL"); 481