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