1/* 2 * linux/arch/arm/common/amba.c 3 * 4 * Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10#include <linux/module.h> 11#include <linux/init.h> 12#include <linux/device.h> 13#include <linux/string.h> 14#include <linux/slab.h> 15#include <linux/io.h> 16#include <linux/pm.h> 17#include <linux/pm_runtime.h> 18#include <linux/pm_domain.h> 19#include <linux/amba/bus.h> 20#include <linux/sizes.h> 21#include <linux/limits.h> 22 23#include <asm/irq.h> 24 25#define to_amba_driver(d) container_of(d, struct amba_driver, drv) 26 27static const struct amba_id * 28amba_lookup(const struct amba_id *table, struct amba_device *dev) 29{ 30 int ret = 0; 31 32 while (table->mask) { 33 ret = (dev->periphid & table->mask) == table->id; 34 if (ret) 35 break; 36 table++; 37 } 38 39 return ret ? table : NULL; 40} 41 42static int amba_match(struct device *dev, struct device_driver *drv) 43{ 44 struct amba_device *pcdev = to_amba_device(dev); 45 struct amba_driver *pcdrv = to_amba_driver(drv); 46 47 /* When driver_override is set, only bind to the matching driver */ 48 if (pcdev->driver_override) 49 return !strcmp(pcdev->driver_override, drv->name); 50 51 return amba_lookup(pcdrv->id_table, pcdev) != NULL; 52} 53 54static int amba_uevent(struct device *dev, struct kobj_uevent_env *env) 55{ 56 struct amba_device *pcdev = to_amba_device(dev); 57 int retval = 0; 58 59 retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid); 60 if (retval) 61 return retval; 62 63 retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid); 64 return retval; 65} 66 67static ssize_t driver_override_show(struct device *_dev, 68 struct device_attribute *attr, char *buf) 69{ 70 struct amba_device *dev = to_amba_device(_dev); 71 72 if (!dev->driver_override) 73 return 0; 74 75 return sprintf(buf, "%s\n", dev->driver_override); 76} 77 78static ssize_t driver_override_store(struct device *_dev, 79 struct device_attribute *attr, 80 const char *buf, size_t count) 81{ 82 struct amba_device *dev = to_amba_device(_dev); 83 char *driver_override, *old = dev->driver_override, *cp; 84 85 if (count > PATH_MAX) 86 return -EINVAL; 87 88 driver_override = kstrndup(buf, count, GFP_KERNEL); 89 if (!driver_override) 90 return -ENOMEM; 91 92 cp = strchr(driver_override, '\n'); 93 if (cp) 94 *cp = '\0'; 95 96 if (strlen(driver_override)) { 97 dev->driver_override = driver_override; 98 } else { 99 kfree(driver_override); 100 dev->driver_override = NULL; 101 } 102 103 kfree(old); 104 105 return count; 106} 107 108#define amba_attr_func(name,fmt,arg...) \ 109static ssize_t name##_show(struct device *_dev, \ 110 struct device_attribute *attr, char *buf) \ 111{ \ 112 struct amba_device *dev = to_amba_device(_dev); \ 113 return sprintf(buf, fmt, arg); \ 114} 115 116#define amba_attr(name,fmt,arg...) \ 117amba_attr_func(name,fmt,arg) \ 118static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL) 119 120amba_attr_func(id, "%08x\n", dev->periphid); 121amba_attr(irq0, "%u\n", dev->irq[0]); 122amba_attr(irq1, "%u\n", dev->irq[1]); 123amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n", 124 (unsigned long long)dev->res.start, (unsigned long long)dev->res.end, 125 dev->res.flags); 126 127static struct device_attribute amba_dev_attrs[] = { 128 __ATTR_RO(id), 129 __ATTR_RO(resource), 130 __ATTR_RW(driver_override), 131 __ATTR_NULL, 132}; 133 134#ifdef CONFIG_PM 135/* 136 * Hooks to provide runtime PM of the pclk (bus clock). It is safe to 137 * enable/disable the bus clock at runtime PM suspend/resume as this 138 * does not result in loss of context. 139 */ 140static int amba_pm_runtime_suspend(struct device *dev) 141{ 142 struct amba_device *pcdev = to_amba_device(dev); 143 int ret = pm_generic_runtime_suspend(dev); 144 145 if (ret == 0 && dev->driver) { 146 if (pm_runtime_is_irq_safe(dev)) 147 clk_disable(pcdev->pclk); 148 else 149 clk_disable_unprepare(pcdev->pclk); 150 } 151 152 return ret; 153} 154 155static int amba_pm_runtime_resume(struct device *dev) 156{ 157 struct amba_device *pcdev = to_amba_device(dev); 158 int ret; 159 160 if (dev->driver) { 161 if (pm_runtime_is_irq_safe(dev)) 162 ret = clk_enable(pcdev->pclk); 163 else 164 ret = clk_prepare_enable(pcdev->pclk); 165 /* Failure is probably fatal to the system, but... */ 166 if (ret) 167 return ret; 168 } 169 170 return pm_generic_runtime_resume(dev); 171} 172#endif /* CONFIG_PM */ 173 174static const struct dev_pm_ops amba_pm = { 175 .suspend = pm_generic_suspend, 176 .resume = pm_generic_resume, 177 .freeze = pm_generic_freeze, 178 .thaw = pm_generic_thaw, 179 .poweroff = pm_generic_poweroff, 180 .restore = pm_generic_restore, 181 SET_RUNTIME_PM_OPS( 182 amba_pm_runtime_suspend, 183 amba_pm_runtime_resume, 184 NULL 185 ) 186}; 187 188/* 189 * Primecells are part of the Advanced Microcontroller Bus Architecture, 190 * so we call the bus "amba". 191 */ 192struct bus_type amba_bustype = { 193 .name = "amba", 194 .dev_attrs = amba_dev_attrs, 195 .match = amba_match, 196 .uevent = amba_uevent, 197 .pm = &amba_pm, 198}; 199 200static int __init amba_init(void) 201{ 202 return bus_register(&amba_bustype); 203} 204 205postcore_initcall(amba_init); 206 207static int amba_get_enable_pclk(struct amba_device *pcdev) 208{ 209 int ret; 210 211 pcdev->pclk = clk_get(&pcdev->dev, "apb_pclk"); 212 if (IS_ERR(pcdev->pclk)) 213 return PTR_ERR(pcdev->pclk); 214 215 ret = clk_prepare_enable(pcdev->pclk); 216 if (ret) 217 clk_put(pcdev->pclk); 218 219 return ret; 220} 221 222static void amba_put_disable_pclk(struct amba_device *pcdev) 223{ 224 clk_disable_unprepare(pcdev->pclk); 225 clk_put(pcdev->pclk); 226} 227 228/* 229 * These are the device model conversion veneers; they convert the 230 * device model structures to our more specific structures. 231 */ 232static int amba_probe(struct device *dev) 233{ 234 struct amba_device *pcdev = to_amba_device(dev); 235 struct amba_driver *pcdrv = to_amba_driver(dev->driver); 236 const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev); 237 int ret; 238 239 do { 240 ret = dev_pm_domain_attach(dev, true); 241 if (ret == -EPROBE_DEFER) 242 break; 243 244 ret = amba_get_enable_pclk(pcdev); 245 if (ret) { 246 dev_pm_domain_detach(dev, true); 247 break; 248 } 249 250 pm_runtime_get_noresume(dev); 251 pm_runtime_set_active(dev); 252 pm_runtime_enable(dev); 253 254 ret = pcdrv->probe(pcdev, id); 255 if (ret == 0) 256 break; 257 258 pm_runtime_disable(dev); 259 pm_runtime_set_suspended(dev); 260 pm_runtime_put_noidle(dev); 261 262 amba_put_disable_pclk(pcdev); 263 dev_pm_domain_detach(dev, true); 264 } while (0); 265 266 return ret; 267} 268 269static int amba_remove(struct device *dev) 270{ 271 struct amba_device *pcdev = to_amba_device(dev); 272 struct amba_driver *drv = to_amba_driver(dev->driver); 273 int ret; 274 275 pm_runtime_get_sync(dev); 276 ret = drv->remove(pcdev); 277 pm_runtime_put_noidle(dev); 278 279 /* Undo the runtime PM settings in amba_probe() */ 280 pm_runtime_disable(dev); 281 pm_runtime_set_suspended(dev); 282 pm_runtime_put_noidle(dev); 283 284 amba_put_disable_pclk(pcdev); 285 dev_pm_domain_detach(dev, true); 286 287 return ret; 288} 289 290static void amba_shutdown(struct device *dev) 291{ 292 struct amba_driver *drv = to_amba_driver(dev->driver); 293 drv->shutdown(to_amba_device(dev)); 294} 295 296/** 297 * amba_driver_register - register an AMBA device driver 298 * @drv: amba device driver structure 299 * 300 * Register an AMBA device driver with the Linux device model 301 * core. If devices pre-exist, the drivers probe function will 302 * be called. 303 */ 304int amba_driver_register(struct amba_driver *drv) 305{ 306 drv->drv.bus = &amba_bustype; 307 308#define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn 309 SETFN(probe); 310 SETFN(remove); 311 SETFN(shutdown); 312 313 return driver_register(&drv->drv); 314} 315 316/** 317 * amba_driver_unregister - remove an AMBA device driver 318 * @drv: AMBA device driver structure to remove 319 * 320 * Unregister an AMBA device driver from the Linux device 321 * model. The device model will call the drivers remove function 322 * for each device the device driver is currently handling. 323 */ 324void amba_driver_unregister(struct amba_driver *drv) 325{ 326 driver_unregister(&drv->drv); 327} 328 329 330static void amba_device_release(struct device *dev) 331{ 332 struct amba_device *d = to_amba_device(dev); 333 334 if (d->res.parent) 335 release_resource(&d->res); 336 kfree(d); 337} 338 339/** 340 * amba_device_add - add a previously allocated AMBA device structure 341 * @dev: AMBA device allocated by amba_device_alloc 342 * @parent: resource parent for this devices resources 343 * 344 * Claim the resource, and read the device cell ID if not already 345 * initialized. Register the AMBA device with the Linux device 346 * manager. 347 */ 348int amba_device_add(struct amba_device *dev, struct resource *parent) 349{ 350 u32 size; 351 void __iomem *tmp; 352 int i, ret; 353 354 WARN_ON(dev->irq[0] == (unsigned int)-1); 355 WARN_ON(dev->irq[1] == (unsigned int)-1); 356 357 ret = request_resource(parent, &dev->res); 358 if (ret) 359 goto err_out; 360 361 /* Hard-coded primecell ID instead of plug-n-play */ 362 if (dev->periphid != 0) 363 goto skip_probe; 364 365 /* 366 * Dynamically calculate the size of the resource 367 * and use this for iomap 368 */ 369 size = resource_size(&dev->res); 370 tmp = ioremap(dev->res.start, size); 371 if (!tmp) { 372 ret = -ENOMEM; 373 goto err_release; 374 } 375 376 ret = amba_get_enable_pclk(dev); 377 if (ret == 0) { 378 u32 pid, cid; 379 380 /* 381 * Read pid and cid based on size of resource 382 * they are located at end of region 383 */ 384 for (pid = 0, i = 0; i < 4; i++) 385 pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) << 386 (i * 8); 387 for (cid = 0, i = 0; i < 4; i++) 388 cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) << 389 (i * 8); 390 391 amba_put_disable_pclk(dev); 392 393 if (cid == AMBA_CID || cid == CORESIGHT_CID) 394 dev->periphid = pid; 395 396 if (!dev->periphid) 397 ret = -ENODEV; 398 } 399 400 iounmap(tmp); 401 402 if (ret) 403 goto err_release; 404 405 skip_probe: 406 ret = device_add(&dev->dev); 407 if (ret) 408 goto err_release; 409 410 if (dev->irq[0]) 411 ret = device_create_file(&dev->dev, &dev_attr_irq0); 412 if (ret == 0 && dev->irq[1]) 413 ret = device_create_file(&dev->dev, &dev_attr_irq1); 414 if (ret == 0) 415 return ret; 416 417 device_unregister(&dev->dev); 418 419 err_release: 420 release_resource(&dev->res); 421 err_out: 422 return ret; 423} 424EXPORT_SYMBOL_GPL(amba_device_add); 425 426static struct amba_device * 427amba_aphb_device_add(struct device *parent, const char *name, 428 resource_size_t base, size_t size, int irq1, int irq2, 429 void *pdata, unsigned int periphid, u64 dma_mask, 430 struct resource *resbase) 431{ 432 struct amba_device *dev; 433 int ret; 434 435 dev = amba_device_alloc(name, base, size); 436 if (!dev) 437 return ERR_PTR(-ENOMEM); 438 439 dev->dev.coherent_dma_mask = dma_mask; 440 dev->irq[0] = irq1; 441 dev->irq[1] = irq2; 442 dev->periphid = periphid; 443 dev->dev.platform_data = pdata; 444 dev->dev.parent = parent; 445 446 ret = amba_device_add(dev, resbase); 447 if (ret) { 448 amba_device_put(dev); 449 return ERR_PTR(ret); 450 } 451 452 return dev; 453} 454 455struct amba_device * 456amba_apb_device_add(struct device *parent, const char *name, 457 resource_size_t base, size_t size, int irq1, int irq2, 458 void *pdata, unsigned int periphid) 459{ 460 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata, 461 periphid, 0, &iomem_resource); 462} 463EXPORT_SYMBOL_GPL(amba_apb_device_add); 464 465struct amba_device * 466amba_ahb_device_add(struct device *parent, const char *name, 467 resource_size_t base, size_t size, int irq1, int irq2, 468 void *pdata, unsigned int periphid) 469{ 470 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata, 471 periphid, ~0ULL, &iomem_resource); 472} 473EXPORT_SYMBOL_GPL(amba_ahb_device_add); 474 475struct amba_device * 476amba_apb_device_add_res(struct device *parent, const char *name, 477 resource_size_t base, size_t size, int irq1, 478 int irq2, void *pdata, unsigned int periphid, 479 struct resource *resbase) 480{ 481 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata, 482 periphid, 0, resbase); 483} 484EXPORT_SYMBOL_GPL(amba_apb_device_add_res); 485 486struct amba_device * 487amba_ahb_device_add_res(struct device *parent, const char *name, 488 resource_size_t base, size_t size, int irq1, 489 int irq2, void *pdata, unsigned int periphid, 490 struct resource *resbase) 491{ 492 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata, 493 periphid, ~0ULL, resbase); 494} 495EXPORT_SYMBOL_GPL(amba_ahb_device_add_res); 496 497 498static void amba_device_initialize(struct amba_device *dev, const char *name) 499{ 500 device_initialize(&dev->dev); 501 if (name) 502 dev_set_name(&dev->dev, "%s", name); 503 dev->dev.release = amba_device_release; 504 dev->dev.bus = &amba_bustype; 505 dev->dev.dma_mask = &dev->dev.coherent_dma_mask; 506 dev->res.name = dev_name(&dev->dev); 507} 508 509/** 510 * amba_device_alloc - allocate an AMBA device 511 * @name: sysfs name of the AMBA device 512 * @base: base of AMBA device 513 * @size: size of AMBA device 514 * 515 * Allocate and initialize an AMBA device structure. Returns %NULL 516 * on failure. 517 */ 518struct amba_device *amba_device_alloc(const char *name, resource_size_t base, 519 size_t size) 520{ 521 struct amba_device *dev; 522 523 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 524 if (dev) { 525 amba_device_initialize(dev, name); 526 dev->res.start = base; 527 dev->res.end = base + size - 1; 528 dev->res.flags = IORESOURCE_MEM; 529 } 530 531 return dev; 532} 533EXPORT_SYMBOL_GPL(amba_device_alloc); 534 535/** 536 * amba_device_register - register an AMBA device 537 * @dev: AMBA device to register 538 * @parent: parent memory resource 539 * 540 * Setup the AMBA device, reading the cell ID if present. 541 * Claim the resource, and register the AMBA device with 542 * the Linux device manager. 543 */ 544int amba_device_register(struct amba_device *dev, struct resource *parent) 545{ 546 amba_device_initialize(dev, dev->dev.init_name); 547 dev->dev.init_name = NULL; 548 549 return amba_device_add(dev, parent); 550} 551 552/** 553 * amba_device_put - put an AMBA device 554 * @dev: AMBA device to put 555 */ 556void amba_device_put(struct amba_device *dev) 557{ 558 put_device(&dev->dev); 559} 560EXPORT_SYMBOL_GPL(amba_device_put); 561 562/** 563 * amba_device_unregister - unregister an AMBA device 564 * @dev: AMBA device to remove 565 * 566 * Remove the specified AMBA device from the Linux device 567 * manager. All files associated with this object will be 568 * destroyed, and device drivers notified that the device has 569 * been removed. The AMBA device's resources including 570 * the amba_device structure will be freed once all 571 * references to it have been dropped. 572 */ 573void amba_device_unregister(struct amba_device *dev) 574{ 575 device_unregister(&dev->dev); 576} 577 578 579struct find_data { 580 struct amba_device *dev; 581 struct device *parent; 582 const char *busid; 583 unsigned int id; 584 unsigned int mask; 585}; 586 587static int amba_find_match(struct device *dev, void *data) 588{ 589 struct find_data *d = data; 590 struct amba_device *pcdev = to_amba_device(dev); 591 int r; 592 593 r = (pcdev->periphid & d->mask) == d->id; 594 if (d->parent) 595 r &= d->parent == dev->parent; 596 if (d->busid) 597 r &= strcmp(dev_name(dev), d->busid) == 0; 598 599 if (r) { 600 get_device(dev); 601 d->dev = pcdev; 602 } 603 604 return r; 605} 606 607/** 608 * amba_find_device - locate an AMBA device given a bus id 609 * @busid: bus id for device (or NULL) 610 * @parent: parent device (or NULL) 611 * @id: peripheral ID (or 0) 612 * @mask: peripheral ID mask (or 0) 613 * 614 * Return the AMBA device corresponding to the supplied parameters. 615 * If no device matches, returns NULL. 616 * 617 * NOTE: When a valid device is found, its refcount is 618 * incremented, and must be decremented before the returned 619 * reference. 620 */ 621struct amba_device * 622amba_find_device(const char *busid, struct device *parent, unsigned int id, 623 unsigned int mask) 624{ 625 struct find_data data; 626 627 data.dev = NULL; 628 data.parent = parent; 629 data.busid = busid; 630 data.id = id; 631 data.mask = mask; 632 633 bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match); 634 635 return data.dev; 636} 637 638/** 639 * amba_request_regions - request all mem regions associated with device 640 * @dev: amba_device structure for device 641 * @name: name, or NULL to use driver name 642 */ 643int amba_request_regions(struct amba_device *dev, const char *name) 644{ 645 int ret = 0; 646 u32 size; 647 648 if (!name) 649 name = dev->dev.driver->name; 650 651 size = resource_size(&dev->res); 652 653 if (!request_mem_region(dev->res.start, size, name)) 654 ret = -EBUSY; 655 656 return ret; 657} 658 659/** 660 * amba_release_regions - release mem regions associated with device 661 * @dev: amba_device structure for device 662 * 663 * Release regions claimed by a successful call to amba_request_regions. 664 */ 665void amba_release_regions(struct amba_device *dev) 666{ 667 u32 size; 668 669 size = resource_size(&dev->res); 670 release_mem_region(dev->res.start, size); 671} 672 673EXPORT_SYMBOL(amba_driver_register); 674EXPORT_SYMBOL(amba_driver_unregister); 675EXPORT_SYMBOL(amba_device_register); 676EXPORT_SYMBOL(amba_device_unregister); 677EXPORT_SYMBOL(amba_find_device); 678EXPORT_SYMBOL(amba_request_regions); 679EXPORT_SYMBOL(amba_release_regions); 680