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         int retval = 0, i = 0, len = 0;
  51
  52         retval = add_uevent_var(envp, nr_env, &i,
  53                                 buf, bufsz, &len,
  54                                 "AMBA_ID=%08x", pcdev->periphid);
  55         envp[i] = NULL;
  56         return retval;
  57 }
  58 #else
  59 #define amba_uevent 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 #define amba_attr_func(name,fmt,arg...)                                 \
  83 static ssize_t name##_show(struct device *_dev,                         \
  84                            struct device_attribute *attr, char *buf)    \
  85 {                                                                       \
  86         struct amba_device *dev = to_amba_device(_dev);                 \
  87         return sprintf(buf, fmt, arg);                                  \
  88 }
  89
  90 #define amba_attr(name,fmt,arg...)      \
  91 amba_attr_func(name,fmt,arg)            \
  92 static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL)
  93
  94 amba_attr_func(id, "%08x\n", dev->periphid);
  95 amba_attr(irq0, "%u\n", dev->irq[0]);
  96 amba_attr(irq1, "%u\n", dev->irq[1]);
  97 amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
  98          (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
  99          dev->res.flags);
 100
 101 static struct device_attribute amba_dev_attrs[] = {
 102         __ATTR_RO(id),
 103         __ATTR_RO(resource),
 104         __ATTR_NULL,
 105 };
 106
 107 /*
 108  * Primecells are part of the Advanced Microcontroller Bus Architecture,
 109  * so we call the bus "amba".
 110  */
 111 static struct bus_type amba_bustype = {
 112         .name           = "amba",
 113         .dev_attrs      = amba_dev_attrs,
 114         .match          = amba_match,
 115         .uevent         = amba_uevent,
 116         .suspend        = amba_suspend,
 117         .resume         = amba_resume,
 118 };
 119
 120 static int __init amba_init(void)
 121 {
 122         return bus_register(&amba_bustype);
 123 }
 124
 125 postcore_initcall(amba_init);
 126
 127 /*
 128  * These are the device model conversion veneers; they convert the
 129  * device model structures to our more specific structures.
 130  */
 131 static int amba_probe(struct device *dev)
 132 {
 133         struct amba_device *pcdev = to_amba_device(dev);
 134         struct amba_driver *pcdrv = to_amba_driver(dev->driver);
 135         struct amba_id *id;
 136
 137         id = amba_lookup(pcdrv->id_table, pcdev);
 138
 139         return pcdrv->probe(pcdev, id);
 140 }
 141
 142 static int amba_remove(struct device *dev)
 143 {
 144         struct amba_driver *drv = to_amba_driver(dev->driver);
 145         return drv->remove(to_amba_device(dev));
 146 }
 147
 148 static void amba_shutdown(struct device *dev)
 149 {
 150         struct amba_driver *drv = to_amba_driver(dev->driver);
 151         drv->shutdown(to_amba_device(dev));
 152 }
 153
 154 /**
 155  *      amba_driver_register - register an AMBA device driver
 156  *      @drv: amba device driver structure
 157  *
 158  *      Register an AMBA device driver with the Linux device model
 159  *      core.  If devices pre-exist, the drivers probe function will
 160  *      be called.
 161  */
 162 int amba_driver_register(struct amba_driver *drv)
 163 {
 164         drv->drv.bus = &amba_bustype;
 165
 166 #define SETFN(fn)       if (drv->fn) drv->drv.fn = amba_##fn
 167         SETFN(probe);
 168         SETFN(remove);
 169         SETFN(shutdown);
 170
 171         return driver_register(&drv->drv);
 172 }
 173
 174 /**
 175  *      amba_driver_unregister - remove an AMBA device driver
 176  *      @drv: AMBA device driver structure to remove
 177  *
 178  *      Unregister an AMBA device driver from the Linux device
 179  *      model.  The device model will call the drivers remove function
 180  *      for each device the device driver is currently handling.
 181  */
 182 void amba_driver_unregister(struct amba_driver *drv)
 183 {
 184         driver_unregister(&drv->drv);
 185 }
 186
 187
 188 static void amba_device_release(struct device *dev)
 189 {
 190         struct amba_device *d = to_amba_device(dev);
 191
 192         if (d->res.parent)
 193                 release_resource(&d->res);
 194         kfree(d);
 195 }
 196
 197 /**
 198  *      amba_device_register - register an AMBA device
 199  *      @dev: AMBA device to register
 200  *      @parent: parent memory resource
 201  *
 202  *      Setup the AMBA device, reading the cell ID if present.
 203  *      Claim the resource, and register the AMBA device with
 204  *      the Linux device manager.
 205  */
 206 int amba_device_register(struct amba_device *dev, struct resource *parent)
 207 {
 208         u32 pid, cid;
 209         void __iomem *tmp;
 210         int i, ret;
 211
 212         dev->dev.release = amba_device_release;
 213         dev->dev.bus = &amba_bustype;
 214         dev->dev.dma_mask = &dev->dma_mask;
 215         dev->res.name = dev->dev.bus_id;
 216
 217         if (!dev->dev.coherent_dma_mask && dev->dma_mask)
 218                 dev_warn(&dev->dev, "coherent dma mask is unset\n");
 219
 220         ret = request_resource(parent, &dev->res);
 221         if (ret)
 222                 goto err_out;
 223
 224         tmp = ioremap(dev->res.start, SZ_4K);
 225         if (!tmp) {
 226                 ret = -ENOMEM;
 227                 goto err_release;
 228         }
 229
 230         for (pid = 0, i = 0; i < 4; i++)
 231                 pid |= (readl(tmp + 0xfe0 + 4 * i) & 255) << (i * 8);
 232         for (cid = 0, i = 0; i < 4; i++)
 233                 cid |= (readl(tmp + 0xff0 + 4 * i) & 255) << (i * 8);
 234
 235         iounmap(tmp);
 236
 237         if (cid == 0xb105f00d)
 238                 dev->periphid = pid;
 239
 240         if (!dev->periphid) {
 241                 ret = -ENODEV;
 242                 goto err_release;
 243         }
 244
 245         ret = device_register(&dev->dev);
 246         if (ret)
 247                 goto err_release;
 248
 249         if (dev->irq[0] != NO_IRQ)
 250                 ret = device_create_file(&dev->dev, &dev_attr_irq0);
 251         if (ret == 0 && dev->irq[1] != NO_IRQ)
 252                 ret = device_create_file(&dev->dev, &dev_attr_irq1);
 253         if (ret == 0)
 254                 return ret;
 255
 256         device_unregister(&dev->dev);
 257
 258  err_release:
 259         release_resource(&dev->res);
 260  err_out:
 261         return ret;
 262 }
 263
 264 /**
 265  *      amba_device_unregister - unregister an AMBA device
 266  *      @dev: AMBA device to remove
 267  *
 268  *      Remove the specified AMBA device from the Linux device
 269  *      manager.  All files associated with this object will be
 270  *      destroyed, and device drivers notified that the device has
 271  *      been removed.  The AMBA device's resources including
 272  *      the amba_device structure will be freed once all
 273  *      references to it have been dropped.
 274  */
 275 void amba_device_unregister(struct amba_device *dev)
 276 {
 277         device_unregister(&dev->dev);
 278 }
 279
 280
 281 struct find_data {
 282         struct amba_device *dev;
 283         struct device *parent;
 284         const char *busid;
 285         unsigned int id;
 286         unsigned int mask;
 287 };
 288
 289 static int amba_find_match(struct device *dev, void *data)
 290 {
 291         struct find_data *d = data;
 292         struct amba_device *pcdev = to_amba_device(dev);
 293         int r;
 294
 295         r = (pcdev->periphid & d->mask) == d->id;
 296         if (d->parent)
 297                 r &= d->parent == dev->parent;
 298         if (d->busid)
 299                 r &= strcmp(dev->bus_id, d->busid) == 0;
 300
 301         if (r) {
 302                 get_device(dev);
 303                 d->dev = pcdev;
 304         }
 305
 306         return r;
 307 }
 308
 309 /**
 310  *      amba_find_device - locate an AMBA device given a bus id
 311  *      @busid: bus id for device (or NULL)
 312  *      @parent: parent device (or NULL)
 313  *      @id: peripheral ID (or 0)
 314  *      @mask: peripheral ID mask (or 0)
 315  *
 316  *      Return the AMBA device corresponding to the supplied parameters.
 317  *      If no device matches, returns NULL.
 318  *
 319  *      NOTE: When a valid device is found, its refcount is
 320  *      incremented, and must be decremented before the returned
 321  *      reference.
 322  */
 323 struct amba_device *
 324 amba_find_device(const char *busid, struct device *parent, unsigned int id,
 325                  unsigned int mask)
 326 {
 327         struct find_data data;
 328
 329         data.dev = NULL;
 330         data.parent = parent;
 331         data.busid = busid;
 332         data.id = id;
 333         data.mask = mask;
 334
 335         bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
 336
 337         return data.dev;
 338 }
 339
 340 /**
 341  *      amba_request_regions - request all mem regions associated with device
 342  *      @dev: amba_device structure for device
 343  *      @name: name, or NULL to use driver name
 344  */
 345 int amba_request_regions(struct amba_device *dev, const char *name)
 346 {
 347         int ret = 0;
 348
 349         if (!name)
 350                 name = dev->dev.driver->name;
 351
 352         if (!request_mem_region(dev->res.start, SZ_4K, name))
 353                 ret = -EBUSY;
 354
 355         return ret;
 356 }
 357
 358 /**
 359  *      amba_release_regions - release mem regions assoicated with device
 360  *      @dev: amba_device structure for device
 361  *
 362  *      Release regions claimed by a successful call to amba_request_regions.
 363  */
 364 void amba_release_regions(struct amba_device *dev)
 365 {
 366         release_mem_region(dev->res.start, SZ_4K);
 367 }
 368
 369 EXPORT_SYMBOL(amba_driver_register);
 370 EXPORT_SYMBOL(amba_driver_unregister);
 371 EXPORT_SYMBOL(amba_device_register);
 372 EXPORT_SYMBOL(amba_device_unregister);
 373 EXPORT_SYMBOL(amba_find_device);
 374 EXPORT_SYMBOL(amba_request_regions);
 375 EXPORT_SYMBOL(amba_release_regions);