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   1 /*
   2  * IBM PowerPC IBM eBus Infrastructure Support.
   3  *
   4  * Copyright (c) 2005 IBM Corporation
   5  *  Joachim Fenkes <fenkes@de.ibm.com>
   6  *  Heiko J Schick <schickhj@de.ibm.com>
   7  *
   8  * All rights reserved.
   9  *
  10  * This source code is distributed under a dual license of GPL v2.0 and OpenIB
  11  * BSD.
  12  *
  13  * OpenIB BSD License
  14  *
  15  * Redistribution and use in source and binary forms, with or without
  16  * modification, are permitted provided that the following conditions are met:
  17  *
  18  * Redistributions of source code must retain the above copyright notice, this
  19  * list of conditions and the following disclaimer.
  20  *
  21  * Redistributions in binary form must reproduce the above copyright notice,
  22  * this list of conditions and the following disclaimer in the documentation
  23  * and/or other materials
  24  * provided with the distribution.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  27  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  30  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  33  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
  34  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  36  * POSSIBILITY OF SUCH DAMAGE.
  37  */
  38
  39 #include <linux/init.h>
  40 #include <linux/console.h>
  41 #include <linux/kobject.h>
  42 #include <linux/dma-mapping.h>
  43 #include <linux/interrupt.h>
  44 #include <linux/of.h>
  45 #include <linux/of_platform.h>
  46 #include <asm/ibmebus.h>
  47 #include <asm/abs_addr.h>
  48
  49 static struct device ibmebus_bus_device = { /* fake "parent" device */
  50         .bus_id = "ibmebus",
  51 };
  52
  53 struct bus_type ibmebus_bus_type;
  54
  55 /* These devices will automatically be added to the bus during init */
  56 static struct of_device_id __initdata builtin_matches[] = {
  57         { .compatible = "IBM,lhca" },
  58         { .compatible = "IBM,lhea" },
  59         {},
  60 };
  61
  62 static void *ibmebus_alloc_coherent(struct device *dev,
  63                                     size_t size,
  64                                     dma_addr_t *dma_handle,
  65                                     gfp_t flag)
  66 {
  67         void *mem;
  68
  69         mem = kmalloc(size, flag);
  70         *dma_handle = (dma_addr_t)mem;
  71
  72         return mem;
  73 }
  74
  75 static void ibmebus_free_coherent(struct device *dev,
  76                                   size_t size, void *vaddr,
  77                                   dma_addr_t dma_handle)
  78 {
  79         kfree(vaddr);
  80 }
  81
  82 static dma_addr_t ibmebus_map_single(struct device *dev,
  83                                      void *ptr,
  84                                      size_t size,
  85                                      enum dma_data_direction direction)
  86 {
  87         return (dma_addr_t)(ptr);
  88 }
  89
  90 static void ibmebus_unmap_single(struct device *dev,
  91                                  dma_addr_t dma_addr,
  92                                  size_t size,
  93                                  enum dma_data_direction direction)
  94 {
  95         return;
  96 }
  97
  98 static int ibmebus_map_sg(struct device *dev,
  99                           struct scatterlist *sgl,
 100                           int nents, enum dma_data_direction direction)
 101 {
 102         struct scatterlist *sg;
 103         int i;
 104
 105         for_each_sg(sgl, sg, nents, i) {
 106                 sg->dma_address = (dma_addr_t) sg_virt(sg);
 107                 sg->dma_length = sg->length;
 108         }
 109
 110         return nents;
 111 }
 112
 113 static void ibmebus_unmap_sg(struct device *dev,
 114                              struct scatterlist *sg,
 115                              int nents, enum dma_data_direction direction)
 116 {
 117         return;
 118 }
 119
 120 static int ibmebus_dma_supported(struct device *dev, u64 mask)
 121 {
 122         return 1;
 123 }
 124
 125 static struct dma_mapping_ops ibmebus_dma_ops = {
 126         .alloc_coherent = ibmebus_alloc_coherent,
 127         .free_coherent  = ibmebus_free_coherent,
 128         .map_single     = ibmebus_map_single,
 129         .unmap_single   = ibmebus_unmap_single,
 130         .map_sg         = ibmebus_map_sg,
 131         .unmap_sg       = ibmebus_unmap_sg,
 132         .dma_supported  = ibmebus_dma_supported,
 133 };
 134
 135 static int ibmebus_match_path(struct device *dev, void *data)
 136 {
 137         struct device_node *dn = to_of_device(dev)->node;
 138         return (dn->full_name &&
 139                 (strcasecmp((char *)data, dn->full_name) == 0));
 140 }
 141
 142 static int ibmebus_match_node(struct device *dev, void *data)
 143 {
 144         return to_of_device(dev)->node == data;
 145 }
 146
 147 static int ibmebus_create_device(struct device_node *dn)
 148 {
 149         struct of_device *dev;
 150         int ret;
 151
 152         dev = of_device_alloc(dn, NULL, &ibmebus_bus_device);
 153         if (!dev)
 154                 return -ENOMEM;
 155
 156         dev->dev.bus = &ibmebus_bus_type;
 157         dev->dev.archdata.dma_ops = &ibmebus_dma_ops;
 158
 159         ret = of_device_register(dev);
 160         if (ret) {
 161                 of_device_free(dev);
 162                 return ret;
 163         }
 164
 165         return 0;
 166 }
 167
 168 static int ibmebus_create_devices(const struct of_device_id *matches)
 169 {
 170         struct device_node *root, *child;
 171         int ret = 0;
 172
 173         root = of_find_node_by_path("/");
 174
 175         for_each_child_of_node(root, child) {
 176                 if (!of_match_node(matches, child))
 177                         continue;
 178
 179                 if (bus_find_device(&ibmebus_bus_type, NULL, child,
 180                                     ibmebus_match_node))
 181                         continue;
 182
 183                 ret = ibmebus_create_device(child);
 184                 if (ret) {
 185                         printk(KERN_ERR "%s: failed to create device (%i)",
 186                                __func__, ret);
 187                         of_node_put(child);
 188                         break;
 189                 }
 190         }
 191
 192         of_node_put(root);
 193         return ret;
 194 }
 195
 196 int ibmebus_register_driver(struct of_platform_driver *drv)
 197 {
 198         /* If the driver uses devices that ibmebus doesn't know, add them */
 199         ibmebus_create_devices(drv->match_table);
 200
 201         return of_register_driver(drv, &ibmebus_bus_type);
 202 }
 203 EXPORT_SYMBOL(ibmebus_register_driver);
 204
 205 void ibmebus_unregister_driver(struct of_platform_driver *drv)
 206 {
 207         of_unregister_driver(drv);
 208 }
 209 EXPORT_SYMBOL(ibmebus_unregister_driver);
 210
 211 int ibmebus_request_irq(u32 ist, irq_handler_t handler,
 212                         unsigned long irq_flags, const char *devname,
 213                         void *dev_id)
 214 {
 215         unsigned int irq = irq_create_mapping(NULL, ist);
 216
 217         if (irq == NO_IRQ)
 218                 return -EINVAL;
 219
 220         return request_irq(irq, handler, irq_flags, devname, dev_id);
 221 }
 222 EXPORT_SYMBOL(ibmebus_request_irq);
 223
 224 void ibmebus_free_irq(u32 ist, void *dev_id)
 225 {
 226         unsigned int irq = irq_find_mapping(NULL, ist);
 227
 228         free_irq(irq, dev_id);
 229 }
 230 EXPORT_SYMBOL(ibmebus_free_irq);
 231
 232 static ssize_t name_show(struct device *dev,
 233                          struct device_attribute *attr, char *buf)
 234 {
 235         return sprintf(buf, "%s\n", to_of_device(dev)->node->name);
 236 }
 237
 238 static struct device_attribute ibmebus_dev_attrs[] = {
 239         __ATTR_RO(name),
 240         __ATTR_NULL
 241 };
 242
 243 static char *ibmebus_chomp(const char *in, size_t count)
 244 {
 245         char *out = kmalloc(count + 1, GFP_KERNEL);
 246
 247         if (!out)
 248                 return NULL;
 249
 250         memcpy(out, in, count);
 251         out[count] = '\0';
 252         if (out[count - 1] == '\n')
 253                 out[count - 1] = '\0';
 254
 255         return out;
 256 }
 257
 258 static ssize_t ibmebus_store_probe(struct bus_type *bus,
 259                                    const char *buf, size_t count)
 260 {
 261         struct device_node *dn = NULL;
 262         char *path;
 263         ssize_t rc = 0;
 264
 265         path = ibmebus_chomp(buf, count);
 266         if (!path)
 267                 return -ENOMEM;
 268
 269         if (bus_find_device(&ibmebus_bus_type, NULL, path,
 270                             ibmebus_match_path)) {
 271                 printk(KERN_WARNING "%s: %s has already been probed\n",
 272                        __func__, path);
 273                 rc = -EEXIST;
 274                 goto out;
 275         }
 276
 277         if ((dn = of_find_node_by_path(path))) {
 278                 rc = ibmebus_create_device(dn);
 279                 of_node_put(dn);
 280         } else {
 281                 printk(KERN_WARNING "%s: no such device node: %s\n",
 282                        __func__, path);
 283                 rc = -ENODEV;
 284         }
 285
 286 out:
 287         kfree(path);
 288         if (rc)
 289                 return rc;
 290         return count;
 291 }
 292
 293 static ssize_t ibmebus_store_remove(struct bus_type *bus,
 294                                     const char *buf, size_t count)
 295 {
 296         struct device *dev;
 297         char *path;
 298
 299         path = ibmebus_chomp(buf, count);
 300         if (!path)
 301                 return -ENOMEM;
 302
 303         if ((dev = bus_find_device(&ibmebus_bus_type, NULL, path,
 304                                    ibmebus_match_path))) {
 305                 of_device_unregister(to_of_device(dev));
 306
 307                 kfree(path);
 308                 return count;
 309         } else {
 310                 printk(KERN_WARNING "%s: %s not on the bus\n",
 311                        __func__, path);
 312
 313                 kfree(path);
 314                 return -ENODEV;
 315         }
 316 }
 317
 318 static struct bus_attribute ibmebus_bus_attrs[] = {
 319         __ATTR(probe, S_IWUSR, NULL, ibmebus_store_probe),
 320         __ATTR(remove, S_IWUSR, NULL, ibmebus_store_remove),
 321         __ATTR_NULL
 322 };
 323
 324 struct bus_type ibmebus_bus_type = {
 325         .uevent    = of_device_uevent,
 326         .dev_attrs = ibmebus_dev_attrs,
 327         .bus_attrs = ibmebus_bus_attrs
 328 };
 329 EXPORT_SYMBOL(ibmebus_bus_type);
 330
 331 static int __init ibmebus_bus_init(void)
 332 {
 333         int err;
 334
 335         printk(KERN_INFO "IBM eBus Device Driver\n");
 336
 337         err = of_bus_type_init(&ibmebus_bus_type, "ibmebus");
 338         if (err) {
 339                 printk(KERN_ERR "%s: failed to register IBM eBus.\n",
 340                        __func__);
 341                 return err;
 342         }
 343
 344         err = device_register(&ibmebus_bus_device);
 345         if (err) {
 346                 printk(KERN_WARNING "%s: device_register returned %i\n",
 347                        __func__, err);
 348                 bus_unregister(&ibmebus_bus_type);
 349
 350                 return err;
 351         }
 352
 353         err = ibmebus_create_devices(builtin_matches);
 354         if (err) {
 355                 device_unregister(&ibmebus_bus_device);
 356                 bus_unregister(&ibmebus_bus_type);
 357                 return err;
 358         }
 359
 360         return 0;
 361 }
 362 postcore_initcall(ibmebus_bus_init);