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 14 #include <asm/io.h> 15 #include <asm/irq.h> 16 #include <asm/hardware/amba.h> 17 #include <asm/sizes.h> 18 19 #define to_amba_device(d) container_of(d, struct amba_device, dev) 20 #define to_amba_driver(d) container_of(d, struct amba_driver, drv) 21 22 static struct amba_id * 23 amba_lookup(struct amba_id *table, struct amba_device *dev) 24 { 25 int ret = 0; 26 27 while (table->mask) { 28 ret = (dev->periphid & table->mask) == table->id; 29 if (ret) 30 break; 31 table++; 32 } 33 34 return ret ? table : NULL; 35 } 36 37 static int amba_match(struct device *dev, struct device_driver *drv) 38 { 39 struct amba_device *pcdev = to_amba_device(dev); 40 struct amba_driver *pcdrv = to_amba_driver(drv); 41 42 return amba_lookup(pcdrv->id_table, pcdev) != NULL; 43 } 44 45 #ifdef CONFIG_HOTPLUG 46 static int amba_hotplug(struct device *dev, char **envp, int nr_env, char *buf, int bufsz) 47 { 48 struct amba_device *pcdev = to_amba_device(dev); 49 50 if (nr_env < 2) 51 return -ENOMEM; 52 53 snprintf(buf, bufsz, "AMBA_ID=%08x", pcdev->periphid); 54 *envp++ = buf; 55 *envp++ = NULL; 56 return 0; 57 } 58 #else 59 #define amba_hotplug NULL 60 #endif 61 62 static int amba_suspend(struct device *dev, u32 state) 63 { 64 struct amba_driver *drv = to_amba_driver(dev->driver); 65 int ret = 0; 66 67 if (dev->driver && drv->suspend) 68 ret = drv->suspend(to_amba_device(dev), state); 69 return ret; 70 } 71 72 static int amba_resume(struct device *dev) 73 { 74 struct amba_driver *drv = to_amba_driver(dev->driver); 75 int ret = 0; 76 77 if (dev->driver && drv->resume) 78 ret = drv->resume(to_amba_device(dev)); 79 return ret; 80 } 81 82 /* 83 * Primecells are part of the Advanced Microcontroller Bus Architecture, 84 * so we call the bus "amba". 85 */ 86 static struct bus_type amba_bustype = { 87 .name = "amba", 88 .match = amba_match, 89 .hotplug = amba_hotplug, 90 .suspend = amba_suspend, 91 .resume = amba_resume, 92 }; 93 94 static int __init amba_init(void) 95 { 96 return bus_register(&amba_bustype); 97 } 98 99 postcore_initcall(amba_init);100 101 /*102 * These are the device model conversion veneers; they convert the103 * device model structures to our more specific structures.104 */105 static int amba_probe(struct device *dev)106 {107 struct amba_device *pcdev = to_amba_device(dev);108 struct amba_driver *pcdrv = to_amba_driver(dev->driver);109 struct amba_id *id;110 111 id = amba_lookup(pcdrv->id_table, pcdev);112 113 return pcdrv->probe(pcdev, id);114 }115 116 static int amba_remove(struct device *dev)117 {118 struct amba_driver *drv = to_amba_driver(dev->driver);119 return drv->remove(to_amba_device(dev));120 }121 122 static void amba_shutdown(struct device *dev)123 {124 struct amba_driver *drv = to_amba_driver(dev->driver);125 drv->shutdown(to_amba_device(dev));126 }127 128 /**129 * amba_driver_register - register an AMBA device driver130 * @drv: amba device driver structure131 *132 * Register an AMBA device driver with the Linux device model133 * core. If devices pre-exist, the drivers probe function will134 * be called.135 */136 int amba_driver_register(struct amba_driver *drv)137 {138 drv->drv.bus = &amba_bustype;139 140 #define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn141 SETFN(probe);142 SETFN(remove);143 SETFN(shutdown);144 145 return driver_register(&drv->drv);146 }147 148 /**149 * amba_driver_unregister - remove an AMBA device driver150 * @drv: AMBA device driver structure to remove151 *152 * Unregister an AMBA device driver from the Linux device153 * model. The device model will call the drivers remove function154 * for each device the device driver is currently handling.155 */156 void amba_driver_unregister(struct amba_driver *drv)157 {158 driver_unregister(&drv->drv);159 }160 161 162 static void amba_device_release(struct device *dev)163 {164 struct amba_device *d = to_amba_device(dev);165 166 if (d->res.parent)167 release_resource(&d->res);168 kfree(d);169 }170 171 #define amba_attr(name,fmt,arg...) /172 static ssize_t show_##name(struct device *_dev, char *buf) /173 { /174 struct amba_device *dev = to_amba_device(_dev); /175 return sprintf(buf, fmt, arg); /176 } /177 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)178 179 amba_attr(id, "%08x/n", dev->periphid);180 amba_attr(irq0, "%u/n", dev->irq[0]);181 amba_attr(irq1, "%u/n", dev->irq[1]);182 amba_attr(resource, "/t%08lx/t%08lx/t%08lx/n",183 dev->res.start, dev->res.end, dev->res.flags);184 185 /**186 * amba_device_register - register an AMBA device187 * @dev: AMBA device to register188 * @parent: parent memory resource189 *190 * Setup the AMBA device, reading the cell ID if present.191 * Claim the resource, and register the AMBA device with192 * the Linux device manager.193 */194 int amba_device_register(struct amba_device *dev, struct resource *parent)195 {196 u32 pid, cid;197 void *tmp;198 int i, ret;199 200 dev->dev.release = amba_device_release;201 dev->dev.bus = &amba_bustype;202 dev->dev.dma_mask = &dev->dma_mask;203 dev->res.name = dev->dev.bus_id;204 205 if (!dev->dev.coherent_dma_mask && dev->dma_mask)206 dev_warn(&dev->dev, "coherent dma mask is unset/n");207 208 ret = request_resource(parent, &dev->res);209 if (ret == 0) {210 tmp = ioremap(dev->res.start, SZ_4K);211 if (!tmp) {212 ret = -ENOMEM;213 goto out;214 }215 216 for (pid = 0, i = 0; i < 4; i++)217 pid |= (readl(tmp + 0xfe0 + 4 * i) & 255) << (i * 8);218 for (cid = 0, i = 0; i < 4; i++)219 cid |= (readl(tmp + 0xff0 + 4 * i) & 255) << (i * 8);220 221 iounmap(tmp);222 223 if (cid == 0xb105f00d)224 dev->periphid = pid;225 226 if (dev->periphid)227 ret = device_register(&dev->dev);228 else229 ret = -ENODEV;230 231 if (ret == 0) {232 device_create_file(&dev->dev, &dev_attr_id);233 if (dev->irq[0] != NO_IRQ)234 device_create_file(&dev->dev, &dev_attr_irq0);235 if (dev->irq[1] != NO_IRQ)236 device_create_file(&dev->dev, &dev_attr_irq1);237 device_create_file(&dev->dev, &dev_attr_resource);238 } else {239 out:240 release_resource(&dev->res);241 }242 }243 return ret;244 }245 246 /**247 * amba_device_unregister - unregister an AMBA device248 * @dev: AMBA device to remove249 *250 * Remove the specified AMBA device from the Linux device251 * manager. All files associated with this object will be252 * destroyed, and device drivers notified that the device has253 * been removed. The AMBA device's resources including254 * the amba_device structure will be freed once all255 * references to it have been dropped.256 */257 void amba_device_unregister(struct amba_device *dev)258 {259 device_unregister(&dev->dev);260 }261 262 263 struct find_data {264 struct amba_device *dev;265 struct device *parent;266 const char *busid;267 unsigned int id;268 unsigned int mask;269 };270 271 static int amba_find_match(struct device *dev, void *data)272 {273 struct find_data *d = data;274 struct amba_device *pcdev = to_amba_device(dev);275 int r;276 277 r = (pcdev->periphid & d->mask) == d->id;278 if (d->parent)279 r &= d->parent == dev->parent;280 if (d->busid)281 r &= strcmp(dev->bus_id, d->busid) == 0;282 283 if (r) {284 get_device(dev);285 d->dev = pcdev;286 }287 288 return r;289 }290 291 /**292 * amba_find_device - locate an AMBA device given a bus id293 * @busid: bus id for device (or NULL)294 * @parent: parent device (or NULL)295 * @id: peripheral ID (or 0)296 * @mask: peripheral ID mask (or 0)297 *298 * Return the AMBA device corresponding to the supplied parameters.299 * If no device matches, returns NULL.300 *301 * NOTE: When a valid device is found, its refcount is302 * incremented, and must be decremented before the returned303 * reference.304 */305 struct amba_device *306 amba_find_device(const char *busid, struct device *parent, unsigned int id,307 unsigned int mask)308 {309 struct find_data data;310 311 data.dev = NULL;312 data.parent = parent;313 data.busid = busid;314 data.id = id;315 data.mask = mask;316 317 bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);318 319 return data.dev;320 }321 322 /**323 * amba_request_regions - request all mem regions associated with device324 * @dev: amba_device structure for device325 * @name: name, or NULL to use driver name326 */327 int amba_request_regions(struct amba_device *dev, const char *name)328 {329 int ret = 0;330 331 if (!name)332 name = dev->dev.driver->name;333 334 if (!request_mem_region(dev->res.start, SZ_4K, name))335 ret = -EBUSY;336 337 return ret;338 }339 340 /**341 * amba_release_regions - release mem regions assoicated with device342 * @dev: amba_device structure for device343 *344 * Release regions claimed by a successful call to amba_request_regions.345 */346 void amba_release_regions(struct amba_device *dev)347 {348 release_mem_region(dev->res.start, SZ_4K);349 }350 351 EXPORT_SYMBOL(amba_driver_register);352 EXPORT_SYMBOL(amba_driver_unregister);353 EXPORT_SYMBOL(amba_device_register);354 EXPORT_SYMBOL(amba_device_unregister);355 EXPORT_SYMBOL(amba_find_device);356 EXPORT_SYMBOL(amba_request_regions);357 EXPORT_SYMBOL(amba_release_regions);358 
