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/amba/bus.h> 16 17 #include <asm/io.h> 18 #include <asm/sizes.h> 19 20 #define to_amba_device(d) container_of(d, struct amba_device, dev) 21 #define to_amba_driver(d) container_of(d, struct amba_driver, drv) 22 23 static struct amba_id * 24 amba_lookup(struct amba_id *table, struct amba_device *dev) 25 { 26 int ret = 0; 27 28 while (table->mask) { 29 ret = (dev->periphid & table->mask) == table->id; 30 if (ret) 31 break; 32 table++; 33 } 34 35 return ret ? table : NULL; 36 } 37 38 static int amba_match(struct device *dev, struct device_driver *drv) 39 { 40 struct amba_device *pcdev = to_amba_device(dev); 41 struct amba_driver *pcdrv = to_amba_driver(drv); 42 43 return amba_lookup(pcdrv->id_table, pcdev) != NULL; 44 } 45 46 #ifdef CONFIG_HOTPLUG 47 static int amba_uevent(struct device *dev, char **envp, int nr_env, char *buf, int bufsz) 48 { 49 struct amba_device *pcdev = to_amba_device(dev); 50 51 if (nr_env < 2) 52 return -ENOMEM; 53 54 snprintf(buf, bufsz, "AMBA_ID=%08x", pcdev->periphid); 55 *envp++ = buf; 56 *envp++ = NULL; 57 return 0; 58 } 59 #else 60 #define amba_uevent NULL 61 #endif 62 63 static int amba_suspend(struct device *dev, pm_message_t state) 64 { 65 struct amba_driver *drv = to_amba_driver(dev->driver); 66 int ret = 0; 67 68 if (dev->driver && drv->suspend) 69 ret = drv->suspend(to_amba_device(dev), state); 70 return ret; 71 } 72 73 static int amba_resume(struct device *dev) 74 { 75 struct amba_driver *drv = to_amba_driver(dev->driver); 76 int ret = 0; 77 78 if (dev->driver && drv->resume) 79 ret = drv->resume(to_amba_device(dev)); 80 return ret; 81 } 82 83 #define amba_attr_func(name,fmt,arg...) \ 84 static ssize_t name##_show(struct device *_dev, \ 85 struct device_attribute *attr, char *buf) \ 86 { \ 87 struct amba_device *dev = to_amba_device(_dev); \ 88 return sprintf(buf, fmt, arg); \ 89 } 90 91 #define amba_attr(name,fmt,arg...) \ 92 amba_attr_func(name,fmt,arg) \ 93 static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL) 94 95 amba_attr_func(id, "%08x\n", dev->periphid); 96 amba_attr(irq0, "%u\n", dev->irq[0]); 97 amba_attr(irq1, "%u\n", dev->irq[1]); 98 amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n", 99 (unsigned long long)dev->res.start, (unsigned long long)dev->res.end, 100 dev->res.flags); 101 102 static struct device_attribute amba_dev_attrs[] = { 103 __ATTR_RO(id), 104 __ATTR_RO(resource), 105 __ATTR_NULL, 106 }; 107 108 /* 109 * Primecells are part of the Advanced Microcontroller Bus Architecture, 110 * so we call the bus "amba". 111 */ 112 static struct bus_type amba_bustype = { 113 .name = "amba", 114 .dev_attrs = amba_dev_attrs, 115 .match = amba_match, 116 .uevent = amba_uevent, 117 .suspend = amba_suspend, 118 .resume = amba_resume, 119 }; 120 121 static int __init amba_init(void) 122 { 123 return bus_register(&amba_bustype); 124 } 125 126 postcore_initcall(amba_init); 127 128 /* 129 * These are the device model conversion veneers; they convert the 130 * device model structures to our more specific structures. 131 */ 132 static int amba_probe(struct device *dev) 133 { 134 struct amba_device *pcdev = to_amba_device(dev); 135 struct amba_driver *pcdrv = to_amba_driver(dev->driver); 136 struct amba_id *id; 137 138 id = amba_lookup(pcdrv->id_table, pcdev); 139 140 return pcdrv->probe(pcdev, id); 141 } 142 143 static int amba_remove(struct device *dev) 144 { 145 struct amba_driver *drv = to_amba_driver(dev->driver); 146 return drv->remove(to_amba_device(dev)); 147 } 148 149 static void amba_shutdown(struct device *dev) 150 { 151 struct amba_driver *drv = to_amba_driver(dev->driver); 152 drv->shutdown(to_amba_device(dev)); 153 } 154 155 /** 156 * amba_driver_register - register an AMBA device driver 157 * @drv: amba device driver structure 158 * 159 * Register an AMBA device driver with the Linux device model 160 * core. If devices pre-exist, the drivers probe function will 161 * be called. 162 */ 163 int amba_driver_register(struct amba_driver *drv) 164 { 165 drv->drv.bus = &amba_bustype; 166 167 #define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn 168 SETFN(probe); 169 SETFN(remove); 170 SETFN(shutdown); 171 172 return driver_register(&drv->drv); 173 } 174 175 /** 176 * amba_driver_unregister - remove an AMBA device driver 177 * @drv: AMBA device driver structure to remove 178 * 179 * Unregister an AMBA device driver from the Linux device 180 * model. The device model will call the drivers remove function 181 * for each device the device driver is currently handling. 182 */ 183 void amba_driver_unregister(struct amba_driver *drv) 184 { 185 driver_unregister(&drv->drv); 186 } 187 188 189 static void amba_device_release(struct device *dev) 190 { 191 struct amba_device *d = to_amba_device(dev); 192 193 if (d->res.parent) 194 release_resource(&d->res); 195 kfree(d); 196 } 197 198 /** 199 * amba_device_register - register an AMBA device 200 * @dev: AMBA device to register 201 * @parent: parent memory resource 202 * 203 * Setup the AMBA device, reading the cell ID if present. 204 * Claim the resource, and register the AMBA device with 205 * the Linux device manager. 206 */ 207 int amba_device_register(struct amba_device *dev, struct resource *parent) 208 { 209 u32 pid, cid; 210 void __iomem *tmp; 211 int i, ret; 212 213 dev->dev.release = amba_device_release; 214 dev->dev.bus = &amba_bustype; 215 dev->dev.dma_mask = &dev->dma_mask; 216 dev->res.name = dev->dev.bus_id; 217 218 if (!dev->dev.coherent_dma_mask && dev->dma_mask) 219 dev_warn(&dev->dev, "coherent dma mask is unset\n"); 220 221 ret = request_resource(parent, &dev->res); 222 if (ret) 223 goto err_out; 224 225 tmp = ioremap(dev->res.start, SZ_4K); 226 if (!tmp) { 227 ret = -ENOMEM; 228 goto err_release; 229 } 230 231 for (pid = 0, i = 0; i < 4; i++) 232 pid |= (readl(tmp + 0xfe0 + 4 * i) & 255) << (i * 8); 233 for (cid = 0, i = 0; i < 4; i++) 234 cid |= (readl(tmp + 0xff0 + 4 * i) & 255) << (i * 8); 235 236 iounmap(tmp); 237 238 if (cid == 0xb105f00d) 239 dev->periphid = pid; 240 241 if (!dev->periphid) { 242 ret = -ENODEV; 243 goto err_release; 244 } 245 246 ret = device_register(&dev->dev); 247 if (ret) 248 goto err_release; 249 250 if (dev->irq[0] != NO_IRQ) 251 ret = device_create_file(&dev->dev, &dev_attr_irq0); 252 if (ret == 0 && dev->irq[1] != NO_IRQ) 253 ret = device_create_file(&dev->dev, &dev_attr_irq1); 254 if (ret == 0) 255 return ret; 256 257 device_unregister(&dev->dev); 258 259 err_release: 260 release_resource(&dev->res); 261 err_out: 262 return ret; 263 } 264 265 /** 266 * amba_device_unregister - unregister an AMBA device 267 * @dev: AMBA device to remove 268 * 269 * Remove the specified AMBA device from the Linux device 270 * manager. All files associated with this object will be 271 * destroyed, and device drivers notified that the device has 272 * been removed. The AMBA device's resources including 273 * the amba_device structure will be freed once all 274 * references to it have been dropped. 275 */ 276 void amba_device_unregister(struct amba_device *dev) 277 { 278 device_unregister(&dev->dev); 279 } 280 281 282 struct find_data { 283 struct amba_device *dev; 284 struct device *parent; 285 const char *busid; 286 unsigned int id; 287 unsigned int mask; 288 }; 289 290 static int amba_find_match(struct device *dev, void *data) 291 { 292 struct find_data *d = data; 293 struct amba_device *pcdev = to_amba_device(dev); 294 int r; 295 296 r = (pcdev->periphid & d->mask) == d->id; 297 if (d->parent) 298 r &= d->parent == dev->parent; 299 if (d->busid) 300 r &= strcmp(dev->bus_id, d->busid) == 0; 301 302 if (r) { 303 get_device(dev); 304 d->dev = pcdev; 305 } 306 307 return r; 308 } 309 310 /** 311 * amba_find_device - locate an AMBA device given a bus id 312 * @busid: bus id for device (or NULL) 313 * @parent: parent device (or NULL) 314 * @id: peripheral ID (or 0) 315 * @mask: peripheral ID mask (or 0) 316 * 317 * Return the AMBA device corresponding to the supplied parameters. 318 * If no device matches, returns NULL. 319 * 320 * NOTE: When a valid device is found, its refcount is 321 * incremented, and must be decremented before the returned 322 * reference. 323 */ 324 struct amba_device * 325 amba_find_device(const char *busid, struct device *parent, unsigned int id, 326 unsigned int mask) 327 { 328 struct find_data data; 329 330 data.dev = NULL; 331 data.parent = parent; 332 data.busid = busid; 333 data.id = id; 334 data.mask = mask; 335 336 bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match); 337 338 return data.dev; 339 } 340 341 /** 342 * amba_request_regions - request all mem regions associated with device 343 * @dev: amba_device structure for device 344 * @name: name, or NULL to use driver name 345 */ 346 int amba_request_regions(struct amba_device *dev, const char *name) 347 { 348 int ret = 0; 349 350 if (!name) 351 name = dev->dev.driver->name; 352 353 if (!request_mem_region(dev->res.start, SZ_4K, name)) 354 ret = -EBUSY; 355 356 return ret; 357 } 358 359 /** 360 * amba_release_regions - release mem regions assoicated with device 361 * @dev: amba_device structure for device 362 * 363 * Release regions claimed by a successful call to amba_request_regions. 364 */ 365 void amba_release_regions(struct amba_device *dev) 366 { 367 release_mem_region(dev->res.start, SZ_4K); 368 } 369 370 EXPORT_SYMBOL(amba_driver_register); 371 EXPORT_SYMBOL(amba_driver_unregister); 372 EXPORT_SYMBOL(amba_device_register); 373 EXPORT_SYMBOL(amba_device_unregister); 374 EXPORT_SYMBOL(amba_find_device); 375 EXPORT_SYMBOL(amba_request_regions); 376 EXPORT_SYMBOL(amba_release_regions); 377