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/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
  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, 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
  60 static 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
  70 static 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...)                                 \
  81 static 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...)      \
  89 amba_attr_func(name,fmt,arg)            \
  90 static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL)
  91
  92 amba_attr_func(id, "%08x\n", dev->periphid);
  93 amba_attr(irq0, "%u\n", dev->irq[0]);
  94 amba_attr(irq1, "%u\n", dev->irq[1]);
  95 amba_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
  99 static 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  */
 109 static 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
 118 static int __init amba_init(void)
 119 {
 120         return bus_register(&amba_bustype);
 121 }
 122
 123 postcore_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  */
 129 static 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
 140 static 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
 146 static 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  */
 160 int 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  */
 180 void amba_driver_unregister(struct amba_driver *drv)
 181 {
 182         driver_unregister(&drv->drv);
 183 }
 184
 185
 186 static 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  */
 204 int amba_device_register(struct amba_device *dev, struct resource *parent)
 205 {
 206         u32 pid, cid;
 207         void __iomem *tmp;
 208         int i, ret;
 209
 210         dev->dev.release = amba_device_release;
 211         dev->dev.bus = &amba_bustype;
 212         dev->dev.dma_mask = &dev->dma_mask;
 213         dev->res.name = dev->dev.bus_id;
 214
 215         if (!dev->dev.coherent_dma_mask && dev->dma_mask)
 216                 dev_warn(&dev->dev, "coherent dma mask is unset\n");
 217
 218         ret = request_resource(parent, &dev->res);
 219         if (ret)
 220                 goto err_out;
 221
 222         tmp = ioremap(dev->res.start, SZ_4K);
 223         if (!tmp) {
 224                 ret = -ENOMEM;
 225                 goto err_release;
 226         }
 227
 228         for (pid = 0, i = 0; i < 4; i++)
 229                 pid |= (readl(tmp + 0xfe0 + 4 * i) & 255) << (i * 8);
 230         for (cid = 0, i = 0; i < 4; i++)
 231                 cid |= (readl(tmp + 0xff0 + 4 * i) & 255) << (i * 8);
 232
 233         iounmap(tmp);
 234
 235         if (cid == 0xb105f00d)
 236                 dev->periphid = pid;
 237
 238         if (!dev->periphid) {
 239                 ret = -ENODEV;
 240                 goto err_release;
 241         }
 242
 243         ret = device_register(&dev->dev);
 244         if (ret)
 245                 goto err_release;
 246
 247         if (dev->irq[0] != NO_IRQ)
 248                 ret = device_create_file(&dev->dev, &dev_attr_irq0);
 249         if (ret == 0 && dev->irq[1] != NO_IRQ)
 250                 ret = device_create_file(&dev->dev, &dev_attr_irq1);
 251         if (ret == 0)
 252                 return ret;
 253
 254         device_unregister(&dev->dev);
 255
 256  err_release:
 257         release_resource(&dev->res);
 258  err_out:
 259         return ret;
 260 }
 261
 262 /**
 263  *      amba_device_unregister - unregister an AMBA device
 264  *      @dev: AMBA device to remove
 265  *
 266  *      Remove the specified AMBA device from the Linux device
 267  *      manager.  All files associated with this object will be
 268  *      destroyed, and device drivers notified that the device has
 269  *      been removed.  The AMBA device's resources including
 270  *      the amba_device structure will be freed once all
 271  *      references to it have been dropped.
 272  */
 273 void amba_device_unregister(struct amba_device *dev)
 274 {
 275         device_unregister(&dev->dev);
 276 }
 277
 278
 279 struct find_data {
 280         struct amba_device *dev;
 281         struct device *parent;
 282         const char *busid;
 283         unsigned int id;
 284         unsigned int mask;
 285 };
 286
 287 static int amba_find_match(struct device *dev, void *data)
 288 {
 289         struct find_data *d = data;
 290         struct amba_device *pcdev = to_amba_device(dev);
 291         int r;
 292
 293         r = (pcdev->periphid & d->mask) == d->id;
 294         if (d->parent)
 295                 r &= d->parent == dev->parent;
 296         if (d->busid)
 297                 r &= strcmp(dev->bus_id, d->busid) == 0;
 298
 299         if (r) {
 300                 get_device(dev);
 301                 d->dev = pcdev;
 302         }
 303
 304         return r;
 305 }
 306
 307 /**
 308  *      amba_find_device - locate an AMBA device given a bus id
 309  *      @busid: bus id for device (or NULL)
 310  *      @parent: parent device (or NULL)
 311  *      @id: peripheral ID (or 0)
 312  *      @mask: peripheral ID mask (or 0)
 313  *
 314  *      Return the AMBA device corresponding to the supplied parameters.
 315  *      If no device matches, returns NULL.
 316  *
 317  *      NOTE: When a valid device is found, its refcount is
 318  *      incremented, and must be decremented before the returned
 319  *      reference.
 320  */
 321 struct amba_device *
 322 amba_find_device(const char *busid, struct device *parent, unsigned int id,
 323                  unsigned int mask)
 324 {
 325         struct find_data data;
 326
 327         data.dev = NULL;
 328         data.parent = parent;
 329         data.busid = busid;
 330         data.id = id;
 331         data.mask = mask;
 332
 333         bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
 334
 335         return data.dev;
 336 }
 337
 338 /**
 339  *      amba_request_regions - request all mem regions associated with device
 340  *      @dev: amba_device structure for device
 341  *      @name: name, or NULL to use driver name
 342  */
 343 int amba_request_regions(struct amba_device *dev, const char *name)
 344 {
 345         int ret = 0;
 346
 347         if (!name)
 348                 name = dev->dev.driver->name;
 349
 350         if (!request_mem_region(dev->res.start, SZ_4K, name))
 351                 ret = -EBUSY;
 352
 353         return ret;
 354 }
 355
 356 /**
 357  *      amba_release_regions - release mem regions assoicated with device
 358  *      @dev: amba_device structure for device
 359  *
 360  *      Release regions claimed by a successful call to amba_request_regions.
 361  */
 362 void amba_release_regions(struct amba_device *dev)
 363 {
 364         release_mem_region(dev->res.start, SZ_4K);
 365 }
 366
 367 EXPORT_SYMBOL(amba_driver_register);
 368 EXPORT_SYMBOL(amba_driver_unregister);
 369 EXPORT_SYMBOL(amba_device_register);
 370 EXPORT_SYMBOL(amba_device_unregister);
 371 EXPORT_SYMBOL(amba_find_device);
 372 EXPORT_SYMBOL(amba_request_regions);
 373 EXPORT_SYMBOL(amba_release_regions);