drivers/amba/bus.c

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