bus.c 8.8 KB

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