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ipack.c
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1 /*
2  * Industry-pack bus support functions.
3  *
4  * (C) 2011 Samuel Iglesias Gonsalvez <[email protected]>, CERN
5  * (C) 2012 Samuel Iglesias Gonsalvez <[email protected]>, Igalia
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License as published by the Free
9  * Software Foundation; version 2 of the License.
10  */
11 
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/idr.h>
15 #include <asm/io.h>
16 #include "ipack.h"
17 
18 #define to_ipack_dev(device) container_of(device, struct ipack_device, dev)
19 #define to_ipack_driver(drv) container_of(drv, struct ipack_driver, driver)
20 
21 static DEFINE_IDA(ipack_ida);
22 
23 static void ipack_device_release(struct device *dev)
24 {
25  struct ipack_device *device = to_ipack_dev(dev);
26  kfree(device->id);
27  kfree(device);
28 }
29 
30 static inline const struct ipack_device_id *
31 ipack_match_one_device(const struct ipack_device_id *id,
32  const struct ipack_device *device)
33 {
34  if ((id->format == IPACK_ANY_FORMAT ||
35  id->format == device->id_format) &&
36  (id->vendor == IPACK_ANY_ID || id->vendor == device->id_vendor) &&
37  (id->device == IPACK_ANY_ID || id->device == device->id_device))
38  return id;
39  return NULL;
40 }
41 
42 static const struct ipack_device_id *
43 ipack_match_id(const struct ipack_device_id *ids, struct ipack_device *idev)
44 {
45  if (ids) {
46  while (ids->vendor || ids->device) {
47  if (ipack_match_one_device(ids, idev))
48  return ids;
49  ids++;
50  }
51  }
52  return NULL;
53 }
54 
55 static int ipack_bus_match(struct device *dev, struct device_driver *drv)
56 {
57  struct ipack_device *idev = to_ipack_dev(dev);
58  struct ipack_driver *idrv = to_ipack_driver(drv);
59  const struct ipack_device_id *found_id;
60 
61  found_id = ipack_match_id(idrv->id_table, idev);
62  return found_id ? 1 : 0;
63 }
64 
65 static int ipack_bus_probe(struct device *device)
66 {
67  struct ipack_device *dev = to_ipack_dev(device);
68  struct ipack_driver *drv = to_ipack_driver(device->driver);
69 
70  if (!drv->ops->probe)
71  return -EINVAL;
72 
73  return drv->ops->probe(dev);
74 }
75 
76 static int ipack_bus_remove(struct device *device)
77 {
78  struct ipack_device *dev = to_ipack_dev(device);
79  struct ipack_driver *drv = to_ipack_driver(device->driver);
80 
81  if (!drv->ops->remove)
82  return -EINVAL;
83 
84  drv->ops->remove(dev);
85  return 0;
86 }
87 
88 #ifdef CONFIG_HOTPLUG
89 
90 static int ipack_uevent(struct device *dev, struct kobj_uevent_env *env)
91 {
92  struct ipack_device *idev;
93 
94  if (!dev)
95  return -ENODEV;
96 
97  idev = to_ipack_dev(dev);
98 
99  if (add_uevent_var(env,
100  "MODALIAS=ipack:f%02Xv%08Xd%08X", idev->id_format,
101  idev->id_vendor, idev->id_device))
102  return -ENOMEM;
103 
104  return 0;
105 }
106 
107 #else /* !CONFIG_HOTPLUG */
108 
109 #define ipack_uevent NULL
110 
111 #endif /* !CONFIG_HOTPLUG */
112 
113 #define ipack_device_attr(field, format_string) \
114 static ssize_t \
115 field##_show(struct device *dev, struct device_attribute *attr, \
116  char *buf) \
117 { \
118  struct ipack_device *idev = to_ipack_dev(dev); \
119  return sprintf(buf, format_string, idev->field); \
120 }
121 
122 static ssize_t id_show(struct device *dev,
123  struct device_attribute *attr, char *buf)
124 {
125  unsigned int i, c, l, s;
126  struct ipack_device *idev = to_ipack_dev(dev);
127 
128 
129  switch (idev->id_format) {
130  case IPACK_ID_VERSION_1:
131  l = 0x7; s = 1; break;
132  case IPACK_ID_VERSION_2:
133  l = 0xf; s = 2; break;
134  default:
135  return -EIO;
136  }
137  c = 0;
138  for (i = 0; i < idev->id_avail; i++) {
139  if (i > 0) {
140  if ((i & l) == 0)
141  buf[c++] = '\n';
142  else if ((i & s) == 0)
143  buf[c++] = ' ';
144  }
145  sprintf(&buf[c], "%02x", idev->id[i]);
146  c += 2;
147  }
148  buf[c++] = '\n';
149  return c;
150 }
151 
152 static ssize_t
153 id_vendor_show(struct device *dev, struct device_attribute *attr, char *buf)
154 {
155  struct ipack_device *idev = to_ipack_dev(dev);
156  switch (idev->id_format) {
157  case IPACK_ID_VERSION_1:
158  return sprintf(buf, "0x%02x\n", idev->id_vendor);
159  case IPACK_ID_VERSION_2:
160  return sprintf(buf, "0x%06x\n", idev->id_vendor);
161  default:
162  return -EIO;
163  }
164 }
165 
166 static ssize_t
167 id_device_show(struct device *dev, struct device_attribute *attr, char *buf)
168 {
169  struct ipack_device *idev = to_ipack_dev(dev);
170  switch (idev->id_format) {
171  case IPACK_ID_VERSION_1:
172  return sprintf(buf, "0x%02x\n", idev->id_device);
173  case IPACK_ID_VERSION_2:
174  return sprintf(buf, "0x%04x\n", idev->id_device);
175  default:
176  return -EIO;
177  }
178 }
179 
180 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
181  char *buf)
182 {
183  struct ipack_device *idev = to_ipack_dev(dev);
184 
185  return sprintf(buf, "ipac:f%02Xv%08Xd%08X", idev->id_format,
186  idev->id_vendor, idev->id_device);
187 }
188 
189 ipack_device_attr(id_format, "0x%hhu\n");
190 
191 static struct device_attribute ipack_dev_attrs[] = {
192  __ATTR_RO(id),
193  __ATTR_RO(id_device),
195  __ATTR_RO(id_vendor),
196  __ATTR_RO(modalias),
197 };
198 
199 static struct bus_type ipack_bus_type = {
200  .name = "ipack",
201  .probe = ipack_bus_probe,
202  .match = ipack_bus_match,
203  .remove = ipack_bus_remove,
204  .dev_attrs = ipack_dev_attrs,
205  .uevent = ipack_uevent,
206 };
207 
208 struct ipack_bus_device *ipack_bus_register(struct device *parent, int slots,
209  const struct ipack_bus_ops *ops)
210 {
211  int bus_nr;
212  struct ipack_bus_device *bus;
213 
214  bus = kzalloc(sizeof(struct ipack_bus_device), GFP_KERNEL);
215  if (!bus)
216  return NULL;
217 
218  bus_nr = ida_simple_get(&ipack_ida, 0, 0, GFP_KERNEL);
219  if (bus_nr < 0) {
220  kfree(bus);
221  return NULL;
222  }
223 
224  bus->bus_nr = bus_nr;
225  bus->parent = parent;
226  bus->slots = slots;
227  bus->ops = ops;
228  return bus;
229 }
231 
232 static int ipack_unregister_bus_member(struct device *dev, void *data)
233 {
234  struct ipack_device *idev = to_ipack_dev(dev);
235  struct ipack_bus_device *bus = data;
236 
237  if (idev->bus_nr == bus->bus_nr)
239 
240  return 1;
241 }
242 
244 {
245  bus_for_each_dev(&ipack_bus_type, NULL, bus, ipack_unregister_bus_member);
246  ida_simple_remove(&ipack_ida, bus->bus_nr);
247  kfree(bus);
248  return 0;
249 }
251 
252 int ipack_driver_register(struct ipack_driver *edrv, struct module *owner,
253  const char *name)
254 {
255  edrv->driver.owner = owner;
256  edrv->driver.name = name;
257  edrv->driver.bus = &ipack_bus_type;
258  return driver_register(&edrv->driver);
259 }
261 
263 {
264  driver_unregister(&edrv->driver);
265 }
267 
268 static u16 ipack_crc_byte(u16 crc, u8 c)
269 {
270  int i;
271 
272  crc ^= c << 8;
273  for (i = 0; i < 8; i++)
274  crc = (crc << 1) ^ ((crc & 0x8000) ? 0x1021 : 0);
275  return crc;
276 }
277 
278 /*
279  * The algorithm in lib/crc-ccitt.c does not seem to apply since it uses the
280  * opposite bit ordering.
281  */
282 static u8 ipack_calc_crc1(struct ipack_device *dev)
283 {
284  u8 c;
285  u16 crc;
286  unsigned int i;
287 
288  crc = 0xffff;
289  for (i = 0; i < dev->id_avail; i++) {
290  c = (i != 11) ? dev->id[i] : 0;
291  crc = ipack_crc_byte(crc, c);
292  }
293  crc = ~crc;
294  return crc & 0xff;
295 }
296 
297 static u16 ipack_calc_crc2(struct ipack_device *dev)
298 {
299  u8 c;
300  u16 crc;
301  unsigned int i;
302 
303  crc = 0xffff;
304  for (i = 0; i < dev->id_avail; i++) {
305  c = ((i != 0x18) && (i != 0x19)) ? dev->id[i] : 0;
306  crc = ipack_crc_byte(crc, c);
307  }
308  crc = ~crc;
309  return crc;
310 }
311 
312 static void ipack_parse_id1(struct ipack_device *dev)
313 {
314  u8 *id = dev->id;
315  u8 crc;
316 
317  dev->id_vendor = id[4];
318  dev->id_device = id[5];
319  dev->speed_8mhz = 1;
320  dev->speed_32mhz = (id[7] == 'H');
321  crc = ipack_calc_crc1(dev);
322  dev->id_crc_correct = (crc == id[11]);
323  if (!dev->id_crc_correct) {
324  dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
325  id[11], crc);
326  }
327 }
328 
329 static void ipack_parse_id2(struct ipack_device *dev)
330 {
331  __be16 *id = (__be16 *) dev->id;
332  u16 flags, crc;
333 
334  dev->id_vendor = ((be16_to_cpu(id[3]) & 0xff) << 16)
335  + be16_to_cpu(id[4]);
336  dev->id_device = be16_to_cpu(id[5]);
337  flags = be16_to_cpu(id[10]);
338  dev->speed_8mhz = !!(flags & 2);
339  dev->speed_32mhz = !!(flags & 4);
340  crc = ipack_calc_crc2(dev);
341  dev->id_crc_correct = (crc == be16_to_cpu(id[12]));
342  if (!dev->id_crc_correct) {
343  dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
344  id[11], crc);
345  }
346 }
347 
348 static int ipack_device_read_id(struct ipack_device *dev)
349 {
350  u8 __iomem *idmem;
351  int i;
352  int ret = 0;
353 
354  ret = dev->bus->ops->map_space(dev, 0, IPACK_ID_SPACE);
355  if (ret) {
356  dev_err(&dev->dev, "error mapping memory\n");
357  return ret;
358  }
359  idmem = dev->id_space.address;
360 
361  /* Determine ID PROM Data Format. If we find the ids "IPAC" or "IPAH"
362  * we are dealing with a IndustryPack format 1 device. If we detect
363  * "VITA4 " (16 bit big endian formatted) we are dealing with a
364  * IndustryPack format 2 device */
365  if ((ioread8(idmem + 1) == 'I') &&
366  (ioread8(idmem + 3) == 'P') &&
367  (ioread8(idmem + 5) == 'A') &&
368  ((ioread8(idmem + 7) == 'C') ||
369  (ioread8(idmem + 7) == 'H'))) {
371  dev->id_avail = ioread8(idmem + 0x15);
372  if ((dev->id_avail < 0x0c) || (dev->id_avail > 0x40)) {
373  dev_warn(&dev->dev, "invalid id size");
374  dev->id_avail = 0x0c;
375  }
376  } else if ((ioread8(idmem + 0) == 'I') &&
377  (ioread8(idmem + 1) == 'V') &&
378  (ioread8(idmem + 2) == 'A') &&
379  (ioread8(idmem + 3) == 'T') &&
380  (ioread8(idmem + 4) == ' ') &&
381  (ioread8(idmem + 5) == '4')) {
383  dev->id_avail = ioread16be(idmem + 0x16);
384  if ((dev->id_avail < 0x1a) || (dev->id_avail > 0x40)) {
385  dev_warn(&dev->dev, "invalid id size");
386  dev->id_avail = 0x1a;
387  }
388  } else {
390  dev->id_avail = 0;
391  }
392 
393  if (!dev->id_avail) {
394  ret = -ENODEV;
395  goto out;
396  }
397 
398  /* Obtain the amount of memory required to store a copy of the complete
399  * ID ROM contents */
400  dev->id = kmalloc(dev->id_avail, GFP_KERNEL);
401  if (!dev->id) {
402  dev_err(&dev->dev, "dev->id alloc failed.\n");
403  ret = -ENOMEM;
404  goto out;
405  }
406  for (i = 0; i < dev->id_avail; i++) {
407  if (dev->id_format == IPACK_ID_VERSION_1)
408  dev->id[i] = ioread8(idmem + (i << 1) + 1);
409  else
410  dev->id[i] = ioread8(idmem + i);
411  }
412 
413  /* now we can finally work with the copy */
414  switch (dev->id_format) {
415  case IPACK_ID_VERSION_1:
416  ipack_parse_id1(dev);
417  break;
418  case IPACK_ID_VERSION_2:
419  ipack_parse_id2(dev);
420  break;
421  }
422 
423 out:
424  dev->bus->ops->unmap_space(dev, IPACK_ID_SPACE);
425 
426  return ret;
427 }
428 
430  int slot)
431 {
432  int ret;
433  struct ipack_device *dev;
434 
435  dev = kzalloc(sizeof(struct ipack_device), GFP_KERNEL);
436  if (!dev)
437  return NULL;
438 
439  dev->dev.bus = &ipack_bus_type;
440  dev->dev.release = ipack_device_release;
441  dev->dev.parent = bus->parent;
442  dev->slot = slot;
443  dev->bus_nr = bus->bus_nr;
444  dev->bus = bus;
445  dev_set_name(&dev->dev,
446  "ipack-dev.%u.%u", dev->bus_nr, dev->slot);
447 
448  if (bus->ops->set_clockrate(dev, 8))
449  dev_warn(&dev->dev, "failed to switch to 8 MHz operation for reading of device ID.\n");
450  if (bus->ops->reset_timeout(dev))
451  dev_warn(&dev->dev, "failed to reset potential timeout.");
452 
453  ret = ipack_device_read_id(dev);
454  if (ret < 0) {
455  dev_err(&dev->dev, "error reading device id section.\n");
456  kfree(dev);
457  return NULL;
458  }
459 
460  /* if the device supports 32 MHz operation, use it. */
461  if (dev->speed_32mhz) {
462  ret = bus->ops->set_clockrate(dev, 32);
463  if (ret < 0)
464  dev_err(&dev->dev, "failed to switch to 32 MHz operation.\n");
465  }
466 
467  ret = device_register(&dev->dev);
468  if (ret < 0) {
469  kfree(dev->id);
470  kfree(dev);
471  return NULL;
472  }
473 
474  return dev;
475 }
477 
479 {
480  device_unregister(&dev->dev);
481 }
483 
484 static int __init ipack_init(void)
485 {
486  ida_init(&ipack_ida);
487  return bus_register(&ipack_bus_type);
488 }
489 
490 static void __exit ipack_exit(void)
491 {
492  bus_unregister(&ipack_bus_type);
493  ida_destroy(&ipack_ida);
494 }
495 
496 module_init(ipack_init);
497 module_exit(ipack_exit);
498 
499 MODULE_AUTHOR("Samuel Iglesias Gonsalvez <[email protected]>");
500 MODULE_LICENSE("GPL");
501 MODULE_DESCRIPTION("Industry-pack bus core");