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 /* 151 * These are the device model conversion veneers; they convert the 152 * device model structures to our more specific structures. 153 */ 154 static int amba_probe(struct device *dev) 155 { 156 struct amba_device *pcdev = to_amba_device(dev); 157 struct amba_driver *pcdrv = to_amba_driver(dev->driver); 158 struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev); 159 int ret; 160 161 do { 162 ret = amba_get_enable_pclk(pcdev); 163 if (ret) 164 break; 165 166 ret = pcdrv->probe(pcdev, id); 167 if (ret == 0) 168 break; 169 170 amba_put_disable_pclk(pcdev); 171 } while (0); 172 173 return ret; 174 } 175 176 static int amba_remove(struct device *dev) 177 { 178 struct amba_device *pcdev = to_amba_device(dev); 179 struct amba_driver *drv = to_amba_driver(dev->driver); 180 int ret = drv->remove(pcdev); 181 182 amba_put_disable_pclk(pcdev); 183 184 return ret; 185 } 186 187 static void amba_shutdown(struct device *dev) 188 { 189 struct amba_driver *drv = to_amba_driver(dev->driver); 190 drv->shutdown(to_amba_device(dev)); 191 } 192 193 /** 194 * amba_driver_register - register an AMBA device driver 195 * @drv: amba device driver structure 196 * 197 * Register an AMBA device driver with the Linux device model 198 * core. If devices pre-exist, the drivers probe function will 199 * be called. 200 */ 201 int amba_driver_register(struct amba_driver *drv) 202 { 203 drv->drv.bus = &amba_bustype; 204 205 #define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn 206 SETFN(probe); 207 SETFN(remove); 208 SETFN(shutdown); 209 210 return driver_register(&drv->drv); 211 } 212 213 /** 214 * amba_driver_unregister - remove an AMBA device driver 215 * @drv: AMBA device driver structure to remove 216 * 217 * Unregister an AMBA device driver from the Linux device 218 * model. The device model will call the drivers remove function 219 * for each device the device driver is currently handling. 220 */ 221 void amba_driver_unregister(struct amba_driver *drv) 222 { 223 driver_unregister(&drv->drv); 224 } 225 226 227 static void amba_device_release(struct device *dev) 228 { 229 struct amba_device *d = to_amba_device(dev); 230 231 if (d->res.parent) 232 release_resource(&d->res); 233 kfree(d); 234 } 235 236 /** 237 * amba_device_register - register an AMBA device 238 * @dev: AMBA device to register 239 * @parent: parent memory resource 240 * 241 * Setup the AMBA device, reading the cell ID if present. 242 * Claim the resource, and register the AMBA device with 243 * the Linux device manager. 244 */ 245 int amba_device_register(struct amba_device *dev, struct resource *parent) 246 { 247 u32 size; 248 void __iomem *tmp; 249 int i, ret; 250 251 device_initialize(&dev->dev); 252 253 /* 254 * Copy from device_add 255 */ 256 if (dev->dev.init_name) { 257 dev_set_name(&dev->dev, "%s", dev->dev.init_name); 258 dev->dev.init_name = NULL; 259 } 260 261 dev->dev.release = amba_device_release; 262 dev->dev.bus = &amba_bustype; 263 dev->dev.dma_mask = &dev->dma_mask; 264 dev->res.name = dev_name(&dev->dev); 265 266 if (!dev->dev.coherent_dma_mask && dev->dma_mask) 267 dev_warn(&dev->dev, "coherent dma mask is unset\n"); 268 269 ret = request_resource(parent, &dev->res); 270 if (ret) 271 goto err_out; 272 273 /* 274 * Dynamically calculate the size of the resource 275 * and use this for iomap 276 */ 277 size = resource_size(&dev->res); 278 tmp = ioremap(dev->res.start, size); 279 if (!tmp) { 280 ret = -ENOMEM; 281 goto err_release; 282 } 283 284 ret = amba_get_enable_pclk(dev); 285 if (ret == 0) { 286 u32 pid, cid; 287 288 /* 289 * Read pid and cid based on size of resource 290 * they are located at end of region 291 */ 292 for (pid = 0, i = 0; i < 4; i++) 293 pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) << 294 (i * 8); 295 for (cid = 0, i = 0; i < 4; i++) 296 cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) << 297 (i * 8); 298 299 amba_put_disable_pclk(dev); 300 301 if (cid == AMBA_CID) 302 dev->periphid = pid; 303 304 if (!dev->periphid) 305 ret = -ENODEV; 306 } 307 308 iounmap(tmp); 309 310 if (ret) 311 goto err_release; 312 313 ret = device_add(&dev->dev); 314 if (ret) 315 goto err_release; 316 317 if (dev->irq[0] != NO_IRQ) 318 ret = device_create_file(&dev->dev, &dev_attr_irq0); 319 if (ret == 0 && dev->irq[1] != NO_IRQ) 320 ret = device_create_file(&dev->dev, &dev_attr_irq1); 321 if (ret == 0) 322 return ret; 323 324 device_unregister(&dev->dev); 325 326 err_release: 327 release_resource(&dev->res); 328 err_out: 329 return ret; 330 } 331 332 /** 333 * amba_device_unregister - unregister an AMBA device 334 * @dev: AMBA device to remove 335 * 336 * Remove the specified AMBA device from the Linux device 337 * manager. All files associated with this object will be 338 * destroyed, and device drivers notified that the device has 339 * been removed. The AMBA device's resources including 340 * the amba_device structure will be freed once all 341 * references to it have been dropped. 342 */ 343 void amba_device_unregister(struct amba_device *dev) 344 { 345 device_unregister(&dev->dev); 346 } 347 348 349 struct find_data { 350 struct amba_device *dev; 351 struct device *parent; 352 const char *busid; 353 unsigned int id; 354 unsigned int mask; 355 }; 356 357 static int amba_find_match(struct device *dev, void *data) 358 { 359 struct find_data *d = data; 360 struct amba_device *pcdev = to_amba_device(dev); 361 int r; 362 363 r = (pcdev->periphid & d->mask) == d->id; 364 if (d->parent) 365 r &= d->parent == dev->parent; 366 if (d->busid) 367 r &= strcmp(dev_name(dev), d->busid) == 0; 368 369 if (r) { 370 get_device(dev); 371 d->dev = pcdev; 372 } 373 374 return r; 375 } 376 377 /** 378 * amba_find_device - locate an AMBA device given a bus id 379 * @busid: bus id for device (or NULL) 380 * @parent: parent device (or NULL) 381 * @id: peripheral ID (or 0) 382 * @mask: peripheral ID mask (or 0) 383 * 384 * Return the AMBA device corresponding to the supplied parameters. 385 * If no device matches, returns NULL. 386 * 387 * NOTE: When a valid device is found, its refcount is 388 * incremented, and must be decremented before the returned 389 * reference. 390 */ 391 struct amba_device * 392 amba_find_device(const char *busid, struct device *parent, unsigned int id, 393 unsigned int mask) 394 { 395 struct find_data data; 396 397 data.dev = NULL; 398 data.parent = parent; 399 data.busid = busid; 400 data.id = id; 401 data.mask = mask; 402 403 bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match); 404 405 return data.dev; 406 } 407 408 /** 409 * amba_request_regions - request all mem regions associated with device 410 * @dev: amba_device structure for device 411 * @name: name, or NULL to use driver name 412 */ 413 int amba_request_regions(struct amba_device *dev, const char *name) 414 { 415 int ret = 0; 416 u32 size; 417 418 if (!name) 419 name = dev->dev.driver->name; 420 421 size = resource_size(&dev->res); 422 423 if (!request_mem_region(dev->res.start, size, name)) 424 ret = -EBUSY; 425 426 return ret; 427 } 428 429 /** 430 * amba_release_regions - release mem regions assoicated with device 431 * @dev: amba_device structure for device 432 * 433 * Release regions claimed by a successful call to amba_request_regions. 434 */ 435 void amba_release_regions(struct amba_device *dev) 436 { 437 u32 size; 438 439 size = resource_size(&dev->res); 440 release_mem_region(dev->res.start, size); 441 } 442 443 EXPORT_SYMBOL(amba_driver_register); 444 EXPORT_SYMBOL(amba_driver_unregister); 445 EXPORT_SYMBOL(amba_device_register); 446 EXPORT_SYMBOL(amba_device_unregister); 447 EXPORT_SYMBOL(amba_find_device); 448 EXPORT_SYMBOL(amba_request_regions); 449 EXPORT_SYMBOL(amba_release_regions); 450