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/amba/bus.h> 17 18 #include <asm/irq.h> 19 #include <asm/sizes.h> 20 21 #define to_amba_device(d) container_of(d, struct amba_device, dev) 22 #define to_amba_driver(d) container_of(d, struct amba_driver, drv) 23 24 static struct amba_id * 25 amba_lookup(struct amba_id *table, struct amba_device *dev) 26 { 27 int ret = 0; 28 29 while (table->mask) { 30 ret = (dev->periphid & table->mask) == table->id; 31 if (ret) 32 break; 33 table++; 34 } 35 36 return ret ? table : NULL; 37 } 38 39 static int amba_match(struct device *dev, struct device_driver *drv) 40 { 41 struct amba_device *pcdev = to_amba_device(dev); 42 struct amba_driver *pcdrv = to_amba_driver(drv); 43 44 return amba_lookup(pcdrv->id_table, pcdev) != NULL; 45 } 46 47 #ifdef CONFIG_HOTPLUG 48 static int amba_uevent(struct device *dev, struct kobj_uevent_env *env) 49 { 50 struct amba_device *pcdev = to_amba_device(dev); 51 int retval = 0; 52 53 retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid); 54 return retval; 55 } 56 #else 57 #define amba_uevent NULL 58 #endif 59 60 static int amba_suspend(struct device *dev, pm_message_t state) 61 { 62 struct amba_driver *drv = to_amba_driver(dev->driver); 63 int ret = 0; 64 65 if (dev->driver && drv->suspend) 66 ret = drv->suspend(to_amba_device(dev), state); 67 return ret; 68 } 69 70 static int amba_resume(struct device *dev) 71 { 72 struct amba_driver *drv = to_amba_driver(dev->driver); 73 int ret = 0; 74 75 if (dev->driver && drv->resume) 76 ret = drv->resume(to_amba_device(dev)); 77 return ret; 78 } 79 80 #define amba_attr_func(name,fmt,arg...) \ 81 static ssize_t name##_show(struct device *_dev, \ 82 struct device_attribute *attr, char *buf) \ 83 { \ 84 struct amba_device *dev = to_amba_device(_dev); \ 85 return sprintf(buf, fmt, arg); \ 86 } 87 88 #define amba_attr(name,fmt,arg...) \ 89 amba_attr_func(name,fmt,arg) \ 90 static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL) 91 92 amba_attr_func(id, "%08x\n", dev->periphid); 93 amba_attr(irq0, "%u\n", dev->irq[0]); 94 amba_attr(irq1, "%u\n", dev->irq[1]); 95 amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n", 96 (unsigned long long)dev->res.start, (unsigned long long)dev->res.end, 97 dev->res.flags); 98 99 static struct device_attribute amba_dev_attrs[] = { 100 __ATTR_RO(id), 101 __ATTR_RO(resource), 102 __ATTR_NULL, 103 }; 104 105 /* 106 * Primecells are part of the Advanced Microcontroller Bus Architecture, 107 * so we call the bus "amba". 108 */ 109 static struct bus_type amba_bustype = { 110 .name = "amba", 111 .dev_attrs = amba_dev_attrs, 112 .match = amba_match, 113 .uevent = amba_uevent, 114 .suspend = amba_suspend, 115 .resume = amba_resume, 116 }; 117 118 static int __init amba_init(void) 119 { 120 return bus_register(&amba_bustype); 121 } 122 123 postcore_initcall(amba_init); 124 125 static int amba_get_enable_pclk(struct amba_device *pcdev) 126 { 127 struct clk *pclk = clk_get(&pcdev->dev, "apb_pclk"); 128 int ret; 129 130 pcdev->pclk = pclk; 131 132 if (IS_ERR(pclk)) 133 return PTR_ERR(pclk); 134 135 ret = clk_enable(pclk); 136 if (ret) 137 clk_put(pclk); 138 139 return ret; 140 } 141 142 static void amba_put_disable_pclk(struct amba_device *pcdev) 143 { 144 struct clk *pclk = pcdev->pclk; 145 146 clk_disable(pclk); 147 clk_put(pclk); 148 } 149 150 static int amba_get_enable_vcore(struct amba_device *pcdev) 151 { 152 struct regulator *vcore = regulator_get(&pcdev->dev, "vcore"); 153 int ret; 154 155 pcdev->vcore = vcore; 156 157 if (IS_ERR(vcore)) { 158 /* It is OK not to supply a vcore regulator */ 159 if (PTR_ERR(vcore) == -ENODEV) 160 return 0; 161 return PTR_ERR(vcore); 162 } 163 164 ret = regulator_enable(vcore); 165 if (ret) { 166 regulator_put(vcore); 167 pcdev->vcore = ERR_PTR(-ENODEV); 168 } 169 170 return ret; 171 } 172 173 static void amba_put_disable_vcore(struct amba_device *pcdev) 174 { 175 struct regulator *vcore = pcdev->vcore; 176 177 if (!IS_ERR(vcore)) { 178 regulator_disable(vcore); 179 regulator_put(vcore); 180 } 181 } 182 183 /* 184 * These are the device model conversion veneers; they convert the 185 * device model structures to our more specific structures. 186 */ 187 static int amba_probe(struct device *dev) 188 { 189 struct amba_device *pcdev = to_amba_device(dev); 190 struct amba_driver *pcdrv = to_amba_driver(dev->driver); 191 struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev); 192 int ret; 193 194 do { 195 ret = amba_get_enable_vcore(pcdev); 196 if (ret) 197 break; 198 199 ret = amba_get_enable_pclk(pcdev); 200 if (ret) 201 break; 202 203 ret = pcdrv->probe(pcdev, id); 204 if (ret == 0) 205 break; 206 207 amba_put_disable_pclk(pcdev); 208 amba_put_disable_vcore(pcdev); 209 } while (0); 210 211 return ret; 212 } 213 214 static int amba_remove(struct device *dev) 215 { 216 struct amba_device *pcdev = to_amba_device(dev); 217 struct amba_driver *drv = to_amba_driver(dev->driver); 218 int ret = drv->remove(pcdev); 219 220 amba_put_disable_pclk(pcdev); 221 amba_put_disable_vcore(pcdev); 222 223 return ret; 224 } 225 226 static void amba_shutdown(struct device *dev) 227 { 228 struct amba_driver *drv = to_amba_driver(dev->driver); 229 drv->shutdown(to_amba_device(dev)); 230 } 231 232 /** 233 * amba_driver_register - register an AMBA device driver 234 * @drv: amba device driver structure 235 * 236 * Register an AMBA device driver with the Linux device model 237 * core. If devices pre-exist, the drivers probe function will 238 * be called. 239 */ 240 int amba_driver_register(struct amba_driver *drv) 241 { 242 drv->drv.bus = &amba_bustype; 243 244 #define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn 245 SETFN(probe); 246 SETFN(remove); 247 SETFN(shutdown); 248 249 return driver_register(&drv->drv); 250 } 251 252 /** 253 * amba_driver_unregister - remove an AMBA device driver 254 * @drv: AMBA device driver structure to remove 255 * 256 * Unregister an AMBA device driver from the Linux device 257 * model. The device model will call the drivers remove function 258 * for each device the device driver is currently handling. 259 */ 260 void amba_driver_unregister(struct amba_driver *drv) 261 { 262 driver_unregister(&drv->drv); 263 } 264 265 266 static void amba_device_release(struct device *dev) 267 { 268 struct amba_device *d = to_amba_device(dev); 269 270 if (d->res.parent) 271 release_resource(&d->res); 272 kfree(d); 273 } 274 275 /** 276 * amba_device_register - register an AMBA device 277 * @dev: AMBA device to register 278 * @parent: parent memory resource 279 * 280 * Setup the AMBA device, reading the cell ID if present. 281 * Claim the resource, and register the AMBA device with 282 * the Linux device manager. 283 */ 284 int amba_device_register(struct amba_device *dev, struct resource *parent) 285 { 286 u32 size; 287 void __iomem *tmp; 288 int i, ret; 289 290 device_initialize(&dev->dev); 291 292 /* 293 * Copy from device_add 294 */ 295 if (dev->dev.init_name) { 296 dev_set_name(&dev->dev, "%s", dev->dev.init_name); 297 dev->dev.init_name = NULL; 298 } 299 300 dev->dev.release = amba_device_release; 301 dev->dev.bus = &amba_bustype; 302 dev->dev.dma_mask = &dev->dma_mask; 303 dev->res.name = dev_name(&dev->dev); 304 305 if (!dev->dev.coherent_dma_mask && dev->dma_mask) 306 dev_warn(&dev->dev, "coherent dma mask is unset\n"); 307 308 ret = request_resource(parent, &dev->res); 309 if (ret) 310 goto err_out; 311 312 /* 313 * Dynamically calculate the size of the resource 314 * and use this for iomap 315 */ 316 size = resource_size(&dev->res); 317 tmp = ioremap(dev->res.start, size); 318 if (!tmp) { 319 ret = -ENOMEM; 320 goto err_release; 321 } 322 323 ret = amba_get_enable_pclk(dev); 324 if (ret == 0) { 325 u32 pid, cid; 326 327 /* 328 * Read pid and cid based on size of resource 329 * they are located at end of region 330 */ 331 for (pid = 0, i = 0; i < 4; i++) 332 pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) << 333 (i * 8); 334 for (cid = 0, i = 0; i < 4; i++) 335 cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) << 336 (i * 8); 337 338 amba_put_disable_pclk(dev); 339 340 if (cid == AMBA_CID) 341 dev->periphid = pid; 342 343 if (!dev->periphid) 344 ret = -ENODEV; 345 } 346 347 iounmap(tmp); 348 349 if (ret) 350 goto err_release; 351 352 ret = device_add(&dev->dev); 353 if (ret) 354 goto err_release; 355 356 if (dev->irq[0] != NO_IRQ) 357 ret = device_create_file(&dev->dev, &dev_attr_irq0); 358 if (ret == 0 && dev->irq[1] != NO_IRQ) 359 ret = device_create_file(&dev->dev, &dev_attr_irq1); 360 if (ret == 0) 361 return ret; 362 363 device_unregister(&dev->dev); 364 365 err_release: 366 release_resource(&dev->res); 367 err_out: 368 return ret; 369 } 370 371 /** 372 * amba_device_unregister - unregister an AMBA device 373 * @dev: AMBA device to remove 374 * 375 * Remove the specified AMBA device from the Linux device 376 * manager. All files associated with this object will be 377 * destroyed, and device drivers notified that the device has 378 * been removed. The AMBA device's resources including 379 * the amba_device structure will be freed once all 380 * references to it have been dropped. 381 */ 382 void amba_device_unregister(struct amba_device *dev) 383 { 384 device_unregister(&dev->dev); 385 } 386 387 388 struct find_data { 389 struct amba_device *dev; 390 struct device *parent; 391 const char *busid; 392 unsigned int id; 393 unsigned int mask; 394 }; 395 396 static int amba_find_match(struct device *dev, void *data) 397 { 398 struct find_data *d = data; 399 struct amba_device *pcdev = to_amba_device(dev); 400 int r; 401 402 r = (pcdev->periphid & d->mask) == d->id; 403 if (d->parent) 404 r &= d->parent == dev->parent; 405 if (d->busid) 406 r &= strcmp(dev_name(dev), d->busid) == 0; 407 408 if (r) { 409 get_device(dev); 410 d->dev = pcdev; 411 } 412 413 return r; 414 } 415 416 /** 417 * amba_find_device - locate an AMBA device given a bus id 418 * @busid: bus id for device (or NULL) 419 * @parent: parent device (or NULL) 420 * @id: peripheral ID (or 0) 421 * @mask: peripheral ID mask (or 0) 422 * 423 * Return the AMBA device corresponding to the supplied parameters. 424 * If no device matches, returns NULL. 425 * 426 * NOTE: When a valid device is found, its refcount is 427 * incremented, and must be decremented before the returned 428 * reference. 429 */ 430 struct amba_device * 431 amba_find_device(const char *busid, struct device *parent, unsigned int id, 432 unsigned int mask) 433 { 434 struct find_data data; 435 436 data.dev = NULL; 437 data.parent = parent; 438 data.busid = busid; 439 data.id = id; 440 data.mask = mask; 441 442 bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match); 443 444 return data.dev; 445 } 446 447 /** 448 * amba_request_regions - request all mem regions associated with device 449 * @dev: amba_device structure for device 450 * @name: name, or NULL to use driver name 451 */ 452 int amba_request_regions(struct amba_device *dev, const char *name) 453 { 454 int ret = 0; 455 u32 size; 456 457 if (!name) 458 name = dev->dev.driver->name; 459 460 size = resource_size(&dev->res); 461 462 if (!request_mem_region(dev->res.start, size, name)) 463 ret = -EBUSY; 464 465 return ret; 466 } 467 468 /** 469 * amba_release_regions - release mem regions assoicated with device 470 * @dev: amba_device structure for device 471 * 472 * Release regions claimed by a successful call to amba_request_regions. 473 */ 474 void amba_release_regions(struct amba_device *dev) 475 { 476 u32 size; 477 478 size = resource_size(&dev->res); 479 release_mem_region(dev->res.start, size); 480 } 481 482 EXPORT_SYMBOL(amba_driver_register); 483 EXPORT_SYMBOL(amba_driver_unregister); 484 EXPORT_SYMBOL(amba_device_register); 485 EXPORT_SYMBOL(amba_device_unregister); 486 EXPORT_SYMBOL(amba_find_device); 487 EXPORT_SYMBOL(amba_request_regions); 488 EXPORT_SYMBOL(amba_release_regions); 489