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/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 #define amba_attr_func(name,fmt,arg...)                                 \
  84 static ssize_t name##_show(struct device *_dev,                         \
  85                            struct device_attribute *attr, char *buf)    \
  86 {                                                                       \
  87         struct amba_device *dev = to_amba_device(_dev);                 \
  88         return sprintf(buf, fmt, arg);                                  \
  89 }
  90
  91 #define amba_attr(name,fmt,arg...)      \
  92 amba_attr_func(name,fmt,arg)            \
  93 static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL)
  94
  95 amba_attr_func(id, "%08x\n", dev->periphid);
  96 amba_attr(irq0, "%u\n", dev->irq[0]);
  97 amba_attr(irq1, "%u\n", dev->irq[1]);
  98 amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
  99          (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
 100          dev->res.flags);
 101
 102 static struct device_attribute amba_dev_attrs[] = {
 103         __ATTR_RO(id),
 104         __ATTR_RO(resource),
 105         __ATTR_NULL,
 106 };
 107
 108 /*
 109  * Primecells are part of the Advanced Microcontroller Bus Architecture,
 110  * so we call the bus "amba".
 111  */
 112 static struct bus_type amba_bustype = {
 113         .name           = "amba",
 114         .dev_attrs      = amba_dev_attrs,
 115         .match          = amba_match,
 116         .uevent         = amba_uevent,
 117         .suspend        = amba_suspend,
 118         .resume         = amba_resume,
 119 };
 120
 121 static int __init amba_init(void)
 122 {
 123         return bus_register(&amba_bustype);
 124 }
 125
 126 postcore_initcall(amba_init);
 127
 128 /*
 129  * These are the device model conversion veneers; they convert the
 130  * device model structures to our more specific structures.
 131  */
 132 static int amba_probe(struct device *dev)
 133 {
 134         struct amba_device *pcdev = to_amba_device(dev);
 135         struct amba_driver *pcdrv = to_amba_driver(dev->driver);
 136         struct amba_id *id;
 137
 138         id = amba_lookup(pcdrv->id_table, pcdev);
 139
 140         return pcdrv->probe(pcdev, id);
 141 }
 142
 143 static int amba_remove(struct device *dev)
 144 {
 145         struct amba_driver *drv = to_amba_driver(dev->driver);
 146         return drv->remove(to_amba_device(dev));
 147 }
 148
 149 static void amba_shutdown(struct device *dev)
 150 {
 151         struct amba_driver *drv = to_amba_driver(dev->driver);
 152         drv->shutdown(to_amba_device(dev));
 153 }
 154
 155 /**
 156  *      amba_driver_register - register an AMBA device driver
 157  *      @drv: amba device driver structure
 158  *
 159  *      Register an AMBA device driver with the Linux device model
 160  *      core.  If devices pre-exist, the drivers probe function will
 161  *      be called.
 162  */
 163 int amba_driver_register(struct amba_driver *drv)
 164 {
 165         drv->drv.bus = &amba_bustype;
 166
 167 #define SETFN(fn)       if (drv->fn) drv->drv.fn = amba_##fn
 168         SETFN(probe);
 169         SETFN(remove);
 170         SETFN(shutdown);
 171
 172         return driver_register(&drv->drv);
 173 }
 174
 175 /**
 176  *      amba_driver_unregister - remove an AMBA device driver
 177  *      @drv: AMBA device driver structure to remove
 178  *
 179  *      Unregister an AMBA device driver from the Linux device
 180  *      model.  The device model will call the drivers remove function
 181  *      for each device the device driver is currently handling.
 182  */
 183 void amba_driver_unregister(struct amba_driver *drv)
 184 {
 185         driver_unregister(&drv->drv);
 186 }
 187
 188
 189 static void amba_device_release(struct device *dev)
 190 {
 191         struct amba_device *d = to_amba_device(dev);
 192
 193         if (d->res.parent)
 194                 release_resource(&d->res);
 195         kfree(d);
 196 }
 197
 198 /**
 199  *      amba_device_register - register an AMBA device
 200  *      @dev: AMBA device to register
 201  *      @parent: parent memory resource
 202  *
 203  *      Setup the AMBA device, reading the cell ID if present.
 204  *      Claim the resource, and register the AMBA device with
 205  *      the Linux device manager.
 206  */
 207 int amba_device_register(struct amba_device *dev, struct resource *parent)
 208 {
 209         u32 pid, cid;
 210         void __iomem *tmp;
 211         int i, ret;
 212
 213         dev->dev.release = amba_device_release;
 214         dev->dev.bus = &amba_bustype;
 215         dev->dev.dma_mask = &dev->dma_mask;
 216         dev->res.name = dev->dev.bus_id;
 217
 218         if (!dev->dev.coherent_dma_mask && dev->dma_mask)
 219                 dev_warn(&dev->dev, "coherent dma mask is unset\n");
 220
 221         ret = request_resource(parent, &dev->res);
 222         if (ret)
 223                 goto err_out;
 224
 225         tmp = ioremap(dev->res.start, SZ_4K);
 226         if (!tmp) {
 227                 ret = -ENOMEM;
 228                 goto err_release;
 229         }
 230
 231         for (pid = 0, i = 0; i < 4; i++)
 232                 pid |= (readl(tmp + 0xfe0 + 4 * i) & 255) << (i * 8);
 233         for (cid = 0, i = 0; i < 4; i++)
 234                 cid |= (readl(tmp + 0xff0 + 4 * i) & 255) << (i * 8);
 235
 236         iounmap(tmp);
 237
 238         if (cid == 0xb105f00d)
 239                 dev->periphid = pid;
 240
 241         if (!dev->periphid) {
 242                 ret = -ENODEV;
 243                 goto err_release;
 244         }
 245
 246         ret = device_register(&dev->dev);
 247         if (ret)
 248                 goto err_release;
 249
 250         if (dev->irq[0] != NO_IRQ)
 251                 ret = device_create_file(&dev->dev, &dev_attr_irq0);
 252         if (ret == 0 && dev->irq[1] != NO_IRQ)
 253                 ret = device_create_file(&dev->dev, &dev_attr_irq1);
 254         if (ret == 0)
 255                 return ret;
 256
 257         device_unregister(&dev->dev);
 258
 259  err_release:
 260         release_resource(&dev->res);
 261  err_out:
 262         return ret;
 263 }
 264
 265 /**
 266  *      amba_device_unregister - unregister an AMBA device
 267  *      @dev: AMBA device to remove
 268  *
 269  *      Remove the specified AMBA device from the Linux device
 270  *      manager.  All files associated with this object will be
 271  *      destroyed, and device drivers notified that the device has
 272  *      been removed.  The AMBA device's resources including
 273  *      the amba_device structure will be freed once all
 274  *      references to it have been dropped.
 275  */
 276 void amba_device_unregister(struct amba_device *dev)
 277 {
 278         device_unregister(&dev->dev);
 279 }
 280
 281
 282 struct find_data {
 283         struct amba_device *dev;
 284         struct device *parent;
 285         const char *busid;
 286         unsigned int id;
 287         unsigned int mask;
 288 };
 289
 290 static int amba_find_match(struct device *dev, void *data)
 291 {
 292         struct find_data *d = data;
 293         struct amba_device *pcdev = to_amba_device(dev);
 294         int r;
 295
 296         r = (pcdev->periphid & d->mask) == d->id;
 297         if (d->parent)
 298                 r &= d->parent == dev->parent;
 299         if (d->busid)
 300                 r &= strcmp(dev->bus_id, d->busid) == 0;
 301
 302         if (r) {
 303                 get_device(dev);
 304                 d->dev = pcdev;
 305         }
 306
 307         return r;
 308 }
 309
 310 /**
 311  *      amba_find_device - locate an AMBA device given a bus id
 312  *      @busid: bus id for device (or NULL)
 313  *      @parent: parent device (or NULL)
 314  *      @id: peripheral ID (or 0)
 315  *      @mask: peripheral ID mask (or 0)
 316  *
 317  *      Return the AMBA device corresponding to the supplied parameters.
 318  *      If no device matches, returns NULL.
 319  *
 320  *      NOTE: When a valid device is found, its refcount is
 321  *      incremented, and must be decremented before the returned
 322  *      reference.
 323  */
 324 struct amba_device *
 325 amba_find_device(const char *busid, struct device *parent, unsigned int id,
 326                  unsigned int mask)
 327 {
 328         struct find_data data;
 329
 330         data.dev = NULL;
 331         data.parent = parent;
 332         data.busid = busid;
 333         data.id = id;
 334         data.mask = mask;
 335
 336         bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
 337
 338         return data.dev;
 339 }
 340
 341 /**
 342  *      amba_request_regions - request all mem regions associated with device
 343  *      @dev: amba_device structure for device
 344  *      @name: name, or NULL to use driver name
 345  */
 346 int amba_request_regions(struct amba_device *dev, const char *name)
 347 {
 348         int ret = 0;
 349
 350         if (!name)
 351                 name = dev->dev.driver->name;
 352
 353         if (!request_mem_region(dev->res.start, SZ_4K, name))
 354                 ret = -EBUSY;
 355
 356         return ret;
 357 }
 358
 359 /**
 360  *      amba_release_regions - release mem regions assoicated with device
 361  *      @dev: amba_device structure for device
 362  *
 363  *      Release regions claimed by a successful call to amba_request_regions.
 364  */
 365 void amba_release_regions(struct amba_device *dev)
 366 {
 367         release_mem_region(dev->res.start, SZ_4K);
 368 }
 369
 370 EXPORT_SYMBOL(amba_driver_register);
 371 EXPORT_SYMBOL(amba_driver_unregister);
 372 EXPORT_SYMBOL(amba_device_register);
 373 EXPORT_SYMBOL(amba_device_unregister);
 374 EXPORT_SYMBOL(amba_find_device);
 375 EXPORT_SYMBOL(amba_request_regions);
 376 EXPORT_SYMBOL(amba_release_regions);