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 /* 126 * These are the device model conversion veneers; they convert the 127 * device model structures to our more specific structures. 128 */ 129 static int amba_probe(struct device *dev) 130 { 131 struct amba_device *pcdev = to_amba_device(dev); 132 struct amba_driver *pcdrv = to_amba_driver(dev->driver); 133 struct amba_id *id; 134 135 id = amba_lookup(pcdrv->id_table, pcdev); 136 137 return pcdrv->probe(pcdev, id); 138 } 139 140 static int amba_remove(struct device *dev) 141 { 142 struct amba_driver *drv = to_amba_driver(dev->driver); 143 return drv->remove(to_amba_device(dev)); 144 } 145 146 static void amba_shutdown(struct device *dev) 147 { 148 struct amba_driver *drv = to_amba_driver(dev->driver); 149 drv->shutdown(to_amba_device(dev)); 150 } 151 152 /** 153 * amba_driver_register - register an AMBA device driver 154 * @drv: amba device driver structure 155 * 156 * Register an AMBA device driver with the Linux device model 157 * core. If devices pre-exist, the drivers probe function will 158 * be called. 159 */ 160 int amba_driver_register(struct amba_driver *drv) 161 { 162 drv->drv.bus = &amba_bustype; 163 164 #define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn 165 SETFN(probe); 166 SETFN(remove); 167 SETFN(shutdown); 168 169 return driver_register(&drv->drv); 170 } 171 172 /** 173 * amba_driver_unregister - remove an AMBA device driver 174 * @drv: AMBA device driver structure to remove 175 * 176 * Unregister an AMBA device driver from the Linux device 177 * model. The device model will call the drivers remove function 178 * for each device the device driver is currently handling. 179 */ 180 void amba_driver_unregister(struct amba_driver *drv) 181 { 182 driver_unregister(&drv->drv); 183 } 184 185 186 static void amba_device_release(struct device *dev) 187 { 188 struct amba_device *d = to_amba_device(dev); 189 190 if (d->res.parent) 191 release_resource(&d->res); 192 kfree(d); 193 } 194 195 /** 196 * amba_device_register - register an AMBA device 197 * @dev: AMBA device to register 198 * @parent: parent memory resource 199 * 200 * Setup the AMBA device, reading the cell ID if present. 201 * Claim the resource, and register the AMBA device with 202 * the Linux device manager. 203 */ 204 int amba_device_register(struct amba_device *dev, struct resource *parent) 205 { 206 u32 pid, cid; 207 void __iomem *tmp; 208 int i, ret; 209 210 dev->dev.release = amba_device_release; 211 dev->dev.bus = &amba_bustype; 212 dev->dev.dma_mask = &dev->dma_mask; 213 dev->res.name = dev->dev.bus_id; 214 215 if (!dev->dev.coherent_dma_mask && dev->dma_mask) 216 dev_warn(&dev->dev, "coherent dma mask is unset\n"); 217 218 ret = request_resource(parent, &dev->res); 219 if (ret) 220 goto err_out; 221 222 tmp = ioremap(dev->res.start, SZ_4K); 223 if (!tmp) { 224 ret = -ENOMEM; 225 goto err_release; 226 } 227 228 for (pid = 0, i = 0; i < 4; i++) 229 pid |= (readl(tmp + 0xfe0 + 4 * i) & 255) << (i * 8); 230 for (cid = 0, i = 0; i < 4; i++) 231 cid |= (readl(tmp + 0xff0 + 4 * i) & 255) << (i * 8); 232 233 iounmap(tmp); 234 235 if (cid == 0xb105f00d) 236 dev->periphid = pid; 237 238 if (!dev->periphid) { 239 ret = -ENODEV; 240 goto err_release; 241 } 242 243 ret = device_register(&dev->dev); 244 if (ret) 245 goto err_release; 246 247 if (dev->irq[0] != NO_IRQ) 248 ret = device_create_file(&dev->dev, &dev_attr_irq0); 249 if (ret == 0 && dev->irq[1] != NO_IRQ) 250 ret = device_create_file(&dev->dev, &dev_attr_irq1); 251 if (ret == 0) 252 return ret; 253 254 device_unregister(&dev->dev); 255 256 err_release: 257 release_resource(&dev->res); 258 err_out: 259 return ret; 260 } 261 262 /** 263 * amba_device_unregister - unregister an AMBA device 264 * @dev: AMBA device to remove 265 * 266 * Remove the specified AMBA device from the Linux device 267 * manager. All files associated with this object will be 268 * destroyed, and device drivers notified that the device has 269 * been removed. The AMBA device's resources including 270 * the amba_device structure will be freed once all 271 * references to it have been dropped. 272 */ 273 void amba_device_unregister(struct amba_device *dev) 274 { 275 device_unregister(&dev->dev); 276 } 277 278 279 struct find_data { 280 struct amba_device *dev; 281 struct device *parent; 282 const char *busid; 283 unsigned int id; 284 unsigned int mask; 285 }; 286 287 static int amba_find_match(struct device *dev, void *data) 288 { 289 struct find_data *d = data; 290 struct amba_device *pcdev = to_amba_device(dev); 291 int r; 292 293 r = (pcdev->periphid & d->mask) == d->id; 294 if (d->parent) 295 r &= d->parent == dev->parent; 296 if (d->busid) 297 r &= strcmp(dev->bus_id, d->busid) == 0; 298 299 if (r) { 300 get_device(dev); 301 d->dev = pcdev; 302 } 303 304 return r; 305 } 306 307 /** 308 * amba_find_device - locate an AMBA device given a bus id 309 * @busid: bus id for device (or NULL) 310 * @parent: parent device (or NULL) 311 * @id: peripheral ID (or 0) 312 * @mask: peripheral ID mask (or 0) 313 * 314 * Return the AMBA device corresponding to the supplied parameters. 315 * If no device matches, returns NULL. 316 * 317 * NOTE: When a valid device is found, its refcount is 318 * incremented, and must be decremented before the returned 319 * reference. 320 */ 321 struct amba_device * 322 amba_find_device(const char *busid, struct device *parent, unsigned int id, 323 unsigned int mask) 324 { 325 struct find_data data; 326 327 data.dev = NULL; 328 data.parent = parent; 329 data.busid = busid; 330 data.id = id; 331 data.mask = mask; 332 333 bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match); 334 335 return data.dev; 336 } 337 338 /** 339 * amba_request_regions - request all mem regions associated with device 340 * @dev: amba_device structure for device 341 * @name: name, or NULL to use driver name 342 */ 343 int amba_request_regions(struct amba_device *dev, const char *name) 344 { 345 int ret = 0; 346 347 if (!name) 348 name = dev->dev.driver->name; 349 350 if (!request_mem_region(dev->res.start, SZ_4K, name)) 351 ret = -EBUSY; 352 353 return ret; 354 } 355 356 /** 357 * amba_release_regions - release mem regions assoicated with device 358 * @dev: amba_device structure for device 359 * 360 * Release regions claimed by a successful call to amba_request_regions. 361 */ 362 void amba_release_regions(struct amba_device *dev) 363 { 364 release_mem_region(dev->res.start, SZ_4K); 365 } 366 367 EXPORT_SYMBOL(amba_driver_register); 368 EXPORT_SYMBOL(amba_driver_unregister); 369 EXPORT_SYMBOL(amba_device_register); 370 EXPORT_SYMBOL(amba_device_unregister); 371 EXPORT_SYMBOL(amba_find_device); 372 EXPORT_SYMBOL(amba_request_regions); 373 EXPORT_SYMBOL(amba_release_regions); 374