linux/drivers/amba/bus.c
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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/io.h>
  16#include <linux/amba/bus.h>
  17
  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
  24static struct amba_id *
  25amba_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
  39static 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
  48static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
  49{
  50        struct amba_device *pcdev = to_amba_device(dev);
  51        int retval = 0;
  52
  53        retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
  54        return retval;
  55}
  56#else
  57#define amba_uevent NULL
  58#endif
  59
  60static int amba_suspend(struct device *dev, pm_message_t state)
  61{
  62        struct amba_driver *drv = to_amba_driver(dev->driver);
  63        int ret = 0;
  64
  65        if (dev->driver && drv->suspend)
  66                ret = drv->suspend(to_amba_device(dev), state);
  67        return ret;
  68}
  69
  70static int amba_resume(struct device *dev)
  71{
  72        struct amba_driver *drv = to_amba_driver(dev->driver);
  73        int ret = 0;
  74
  75        if (dev->driver && drv->resume)
  76                ret = drv->resume(to_amba_device(dev));
  77        return ret;
  78}
  79
  80#define amba_attr_func(name,fmt,arg...)                                 \
  81static ssize_t name##_show(struct device *_dev,                         \
  82                           struct device_attribute *attr, char *buf)    \
  83{                                                                       \
  84        struct amba_device *dev = to_amba_device(_dev);                 \
  85        return sprintf(buf, fmt, arg);                                  \
  86}
  87
  88#define amba_attr(name,fmt,arg...)      \
  89amba_attr_func(name,fmt,arg)            \
  90static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL)
  91
  92amba_attr_func(id, "%08x\n", dev->periphid);
  93amba_attr(irq0, "%u\n", dev->irq[0]);
  94amba_attr(irq1, "%u\n", dev->irq[1]);
  95amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
  96         (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
  97         dev->res.flags);
  98
  99static struct device_attribute amba_dev_attrs[] = {
 100        __ATTR_RO(id),
 101        __ATTR_RO(resource),
 102        __ATTR_NULL,
 103};
 104
 105/*
 106 * Primecells are part of the Advanced Microcontroller Bus Architecture,
 107 * so we call the bus "amba".
 108 */
 109static struct bus_type amba_bustype = {
 110        .name           = "amba",
 111        .dev_attrs      = amba_dev_attrs,
 112        .match          = amba_match,
 113        .uevent         = amba_uevent,
 114        .suspend        = amba_suspend,
 115        .resume         = amba_resume,
 116};
 117
 118static int __init amba_init(void)
 119{
 120        return bus_register(&amba_bustype);
 121}
 122
 123postcore_initcall(amba_init);
 124
 125/*
 126 * These are the device model conversion veneers; they convert the
 127 * device model structures to our more specific structures.
 128 */
 129static int amba_probe(struct device *dev)
 130{
 131        struct amba_device *pcdev = to_amba_device(dev);
 132        struct amba_driver *pcdrv = to_amba_driver(dev->driver);
 133        struct amba_id *id;
 134
 135        id = amba_lookup(pcdrv->id_table, pcdev);
 136
 137        return pcdrv->probe(pcdev, id);
 138}
 139
 140static int amba_remove(struct device *dev)
 141{
 142        struct amba_driver *drv = to_amba_driver(dev->driver);
 143        return drv->remove(to_amba_device(dev));
 144}
 145
 146static void amba_shutdown(struct device *dev)
 147{
 148        struct amba_driver *drv = to_amba_driver(dev->driver);
 149        drv->shutdown(to_amba_device(dev));
 150}
 151
 152/**
 153 *      amba_driver_register - register an AMBA device driver
 154 *      @drv: amba device driver structure
 155 *
 156 *      Register an AMBA device driver with the Linux device model
 157 *      core.  If devices pre-exist, the drivers probe function will
 158 *      be called.
 159 */
 160int amba_driver_register(struct amba_driver *drv)
 161{
 162        drv->drv.bus = &amba_bustype;
 163
 164#define SETFN(fn)       if (drv->fn) drv->drv.fn = amba_##fn
 165        SETFN(probe);
 166        SETFN(remove);
 167        SETFN(shutdown);
 168
 169        return driver_register(&drv->drv);
 170}
 171
 172/**
 173 *      amba_driver_unregister - remove an AMBA device driver
 174 *      @drv: AMBA device driver structure to remove
 175 *
 176 *      Unregister an AMBA device driver from the Linux device
 177 *      model.  The device model will call the drivers remove function
 178 *      for each device the device driver is currently handling.
 179 */
 180void amba_driver_unregister(struct amba_driver *drv)
 181{
 182        driver_unregister(&drv->drv);
 183}
 184
 185
 186static void amba_device_release(struct device *dev)
 187{
 188        struct amba_device *d = to_amba_device(dev);
 189
 190        if (d->res.parent)
 191                release_resource(&d->res);
 192        kfree(d);
 193}
 194
 195/**
 196 *      amba_device_register - register an AMBA device
 197 *      @dev: AMBA device to register
 198 *      @parent: parent memory resource
 199 *
 200 *      Setup the AMBA device, reading the cell ID if present.
 201 *      Claim the resource, and register the AMBA device with
 202 *      the Linux device manager.
 203 */
 204int amba_device_register(struct amba_device *dev, struct resource *parent)
 205{
 206        u32 pid, cid;
 207        u32 size;
 208        void __iomem *tmp;
 209        int i, ret;
 210
 211        device_initialize(&dev->dev);
 212
 213        /*
 214         * Copy from device_add
 215         */
 216        if (dev->dev.init_name) {
 217                dev_set_name(&dev->dev, "%s", dev->dev.init_name);
 218                dev->dev.init_name = NULL;
 219        }
 220
 221        dev->dev.release = amba_device_release;
 222        dev->dev.bus = &amba_bustype;
 223        dev->dev.dma_mask = &dev->dma_mask;
 224        dev->res.name = dev_name(&dev->dev);
 225
 226        if (!dev->dev.coherent_dma_mask && dev->dma_mask)
 227                dev_warn(&dev->dev, "coherent dma mask is unset\n");
 228
 229        ret = request_resource(parent, &dev->res);
 230        if (ret)
 231                goto err_out;
 232
 233        /*
 234         * Dynamically calculate the size of the resource
 235         * and use this for iomap
 236         */
 237        size = resource_size(&dev->res);
 238        tmp = ioremap(dev->res.start, size);
 239        if (!tmp) {
 240                ret = -ENOMEM;
 241                goto err_release;
 242        }
 243
 244        /*
 245         * Read pid and cid based on size of resource
 246         * they are located at end of region
 247         */
 248        for (pid = 0, i = 0; i < 4; i++)
 249                pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) << (i * 8);
 250        for (cid = 0, i = 0; i < 4; i++)
 251                cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) << (i * 8);
 252
 253        iounmap(tmp);
 254
 255        if (cid == 0xb105f00d)
 256                dev->periphid = pid;
 257
 258        if (!dev->periphid) {
 259                ret = -ENODEV;
 260                goto err_release;
 261        }
 262
 263        ret = device_add(&dev->dev);
 264        if (ret)
 265                goto err_release;
 266
 267        if (dev->irq[0] != NO_IRQ)
 268                ret = device_create_file(&dev->dev, &dev_attr_irq0);
 269        if (ret == 0 && dev->irq[1] != NO_IRQ)
 270                ret = device_create_file(&dev->dev, &dev_attr_irq1);
 271        if (ret == 0)
 272                return ret;
 273
 274        device_unregister(&dev->dev);
 275
 276 err_release:
 277        release_resource(&dev->res);
 278 err_out:
 279        return ret;
 280}
 281
 282/**
 283 *      amba_device_unregister - unregister an AMBA device
 284 *      @dev: AMBA device to remove
 285 *
 286 *      Remove the specified AMBA device from the Linux device
 287 *      manager.  All files associated with this object will be
 288 *      destroyed, and device drivers notified that the device has
 289 *      been removed.  The AMBA device's resources including
 290 *      the amba_device structure will be freed once all
 291 *      references to it have been dropped.
 292 */
 293void amba_device_unregister(struct amba_device *dev)
 294{
 295        device_unregister(&dev->dev);
 296}
 297
 298
 299struct find_data {
 300        struct amba_device *dev;
 301        struct device *parent;
 302        const char *busid;
 303        unsigned int id;
 304        unsigned int mask;
 305};
 306
 307static int amba_find_match(struct device *dev, void *data)
 308{
 309        struct find_data *d = data;
 310        struct amba_device *pcdev = to_amba_device(dev);
 311        int r;
 312
 313        r = (pcdev->periphid & d->mask) == d->id;
 314        if (d->parent)
 315                r &= d->parent == dev->parent;
 316        if (d->busid)
 317                r &= strcmp(dev_name(dev), d->busid) == 0;
 318
 319        if (r) {
 320                get_device(dev);
 321                d->dev = pcdev;
 322        }
 323
 324        return r;
 325}
 326
 327/**
 328 *      amba_find_device - locate an AMBA device given a bus id
 329 *      @busid: bus id for device (or NULL)
 330 *      @parent: parent device (or NULL)
 331 *      @id: peripheral ID (or 0)
 332 *      @mask: peripheral ID mask (or 0)
 333 *
 334 *      Return the AMBA device corresponding to the supplied parameters.
 335 *      If no device matches, returns NULL.
 336 *
 337 *      NOTE: When a valid device is found, its refcount is
 338 *      incremented, and must be decremented before the returned
 339 *      reference.
 340 */
 341struct amba_device *
 342amba_find_device(const char *busid, struct device *parent, unsigned int id,
 343                 unsigned int mask)
 344{
 345        struct find_data data;
 346
 347        data.dev = NULL;
 348        data.parent = parent;
 349        data.busid = busid;
 350        data.id = id;
 351        data.mask = mask;
 352
 353        bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
 354
 355        return data.dev;
 356}
 357
 358/**
 359 *      amba_request_regions - request all mem regions associated with device
 360 *      @dev: amba_device structure for device
 361 *      @name: name, or NULL to use driver name
 362 */
 363int amba_request_regions(struct amba_device *dev, const char *name)
 364{
 365        int ret = 0;
 366        u32 size;
 367
 368        if (!name)
 369                name = dev->dev.driver->name;
 370
 371        size = resource_size(&dev->res);
 372
 373        if (!request_mem_region(dev->res.start, size, name))
 374                ret = -EBUSY;
 375
 376        return ret;
 377}
 378
 379/**
 380 *      amba_release_regions - release mem regions assoicated with device
 381 *      @dev: amba_device structure for device
 382 *
 383 *      Release regions claimed by a successful call to amba_request_regions.
 384 */
 385void amba_release_regions(struct amba_device *dev)
 386{
 387        u32 size;
 388
 389        size = resource_size(&dev->res);
 390        release_mem_region(dev->res.start, size);
 391}
 392
 393EXPORT_SYMBOL(amba_driver_register);
 394EXPORT_SYMBOL(amba_driver_unregister);
 395EXPORT_SYMBOL(amba_device_register);
 396EXPORT_SYMBOL(amba_device_unregister);
 397EXPORT_SYMBOL(amba_find_device);
 398EXPORT_SYMBOL(amba_request_regions);
 399EXPORT_SYMBOL(amba_release_regions);
 400
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