arch/arm/common/amba.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
  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, pm_message_t 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 the
 103  * 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 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
 140 #define SETFN(fn)       if (drv->fn) drv->drv.fn = amba_##fn
 141         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 driver
 150  *      @drv: AMBA device driver structure to remove
 151  *
 152  *      Unregister an AMBA device driver from the Linux device
 153  *      model.  The device model will call the drivers remove function
 154  *      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 device
 187  *      @dev: AMBA device to register
 188  *      @parent: parent memory resource
 189  *
 190  *      Setup the AMBA device, reading the cell ID if present.
 191  *      Claim the resource, and register the AMBA device with
 192  *      the Linux device manager.
 193  */
 194 int amba_device_register(struct amba_device *dev, struct resource *parent)
 195 {
 196         u32 pid, cid;
 197         void __iomem *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                 else
 229                         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 device
 248  *      @dev: AMBA device to remove
 249  *
 250  *      Remove the specified AMBA device from the Linux device
 251  *      manager.  All files associated with this object will be
 252  *      destroyed, and device drivers notified that the device has
 253  *      been removed.  The AMBA device's resources including
 254  *      the amba_device structure will be freed once all
 255  *      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 id
 293  *      @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 is
 302  *      incremented, and must be decremented before the returned
 303  *      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 device
 324  *      @dev: amba_device structure for device
 325  *      @name: name, or NULL to use driver name
 326  */
 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 device
 342  *      @dev: amba_device structure for device
 343  *
 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);