xref: /linux/drivers/ipack/ipack.c (revision bbcd53c960713507ae764bf81970651b5577b95a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Industry-pack bus support functions.
4  *
5  * Copyright (C) 2011-2012 CERN (www.cern.ch)
6  * Author: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
7  */
8 
9 #include <linux/module.h>
10 #include <linux/slab.h>
11 #include <linux/idr.h>
12 #include <linux/io.h>
13 #include <linux/ipack.h>
14 
15 #define to_ipack_dev(device) container_of(device, struct ipack_device, dev)
16 #define to_ipack_driver(drv) container_of(drv, struct ipack_driver, driver)
17 
18 static DEFINE_IDA(ipack_ida);
19 
20 static void ipack_device_release(struct device *dev)
21 {
22 	struct ipack_device *device = to_ipack_dev(dev);
23 	kfree(device->id);
24 	device->release(device);
25 }
26 
27 static inline const struct ipack_device_id *
28 ipack_match_one_device(const struct ipack_device_id *id,
29 		       const struct ipack_device *device)
30 {
31 	if ((id->format == IPACK_ANY_FORMAT ||
32 				id->format == device->id_format) &&
33 	    (id->vendor == IPACK_ANY_ID || id->vendor == device->id_vendor) &&
34 	    (id->device == IPACK_ANY_ID || id->device == device->id_device))
35 		return id;
36 	return NULL;
37 }
38 
39 static const struct ipack_device_id *
40 ipack_match_id(const struct ipack_device_id *ids, struct ipack_device *idev)
41 {
42 	if (ids) {
43 		while (ids->vendor || ids->device) {
44 			if (ipack_match_one_device(ids, idev))
45 				return ids;
46 			ids++;
47 		}
48 	}
49 	return NULL;
50 }
51 
52 static int ipack_bus_match(struct device *dev, struct device_driver *drv)
53 {
54 	struct ipack_device *idev = to_ipack_dev(dev);
55 	struct ipack_driver *idrv = to_ipack_driver(drv);
56 	const struct ipack_device_id *found_id;
57 
58 	found_id = ipack_match_id(idrv->id_table, idev);
59 	return found_id ? 1 : 0;
60 }
61 
62 static int ipack_bus_probe(struct device *device)
63 {
64 	struct ipack_device *dev = to_ipack_dev(device);
65 	struct ipack_driver *drv = to_ipack_driver(device->driver);
66 
67 	return drv->ops->probe(dev);
68 }
69 
70 static int ipack_bus_remove(struct device *device)
71 {
72 	struct ipack_device *dev = to_ipack_dev(device);
73 	struct ipack_driver *drv = to_ipack_driver(device->driver);
74 
75 	if (drv->ops->remove)
76 		drv->ops->remove(dev);
77 
78 	return 0;
79 }
80 
81 static int ipack_uevent(struct device *dev, struct kobj_uevent_env *env)
82 {
83 	struct ipack_device *idev;
84 
85 	if (!dev)
86 		return -ENODEV;
87 
88 	idev = to_ipack_dev(dev);
89 
90 	if (add_uevent_var(env,
91 			   "MODALIAS=ipack:f%02Xv%08Xd%08X", idev->id_format,
92 			   idev->id_vendor, idev->id_device))
93 		return -ENOMEM;
94 
95 	return 0;
96 }
97 
98 #define ipack_device_attr(field, format_string)				\
99 static ssize_t								\
100 field##_show(struct device *dev, struct device_attribute *attr,		\
101 		char *buf)						\
102 {									\
103 	struct ipack_device *idev = to_ipack_dev(dev);			\
104 	return sprintf(buf, format_string, idev->field);		\
105 }
106 
107 static ssize_t id_show(struct device *dev,
108 		       struct device_attribute *attr, char *buf)
109 {
110 	unsigned int i, c, l, s;
111 	struct ipack_device *idev = to_ipack_dev(dev);
112 
113 
114 	switch (idev->id_format) {
115 	case IPACK_ID_VERSION_1:
116 		l = 0x7; s = 1; break;
117 	case IPACK_ID_VERSION_2:
118 		l = 0xf; s = 2; break;
119 	default:
120 		return -EIO;
121 	}
122 	c = 0;
123 	for (i = 0; i < idev->id_avail; i++) {
124 		if (i > 0) {
125 			if ((i & l) == 0)
126 				buf[c++] = '\n';
127 			else if ((i & s) == 0)
128 				buf[c++] = ' ';
129 		}
130 		sprintf(&buf[c], "%02x", idev->id[i]);
131 		c += 2;
132 	}
133 	buf[c++] = '\n';
134 	return c;
135 }
136 
137 static ssize_t
138 id_vendor_show(struct device *dev, struct device_attribute *attr, char *buf)
139 {
140 	struct ipack_device *idev = to_ipack_dev(dev);
141 	switch (idev->id_format) {
142 	case IPACK_ID_VERSION_1:
143 		return sprintf(buf, "0x%02x\n", idev->id_vendor);
144 	case IPACK_ID_VERSION_2:
145 		return sprintf(buf, "0x%06x\n", idev->id_vendor);
146 	default:
147 		return -EIO;
148 	}
149 }
150 
151 static ssize_t
152 id_device_show(struct device *dev, struct device_attribute *attr, char *buf)
153 {
154 	struct ipack_device *idev = to_ipack_dev(dev);
155 	switch (idev->id_format) {
156 	case IPACK_ID_VERSION_1:
157 		return sprintf(buf, "0x%02x\n", idev->id_device);
158 	case IPACK_ID_VERSION_2:
159 		return sprintf(buf, "0x%04x\n", idev->id_device);
160 	default:
161 		return -EIO;
162 	}
163 }
164 
165 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
166 			     char *buf)
167 {
168 	struct ipack_device *idev = to_ipack_dev(dev);
169 
170 	return sprintf(buf, "ipac:f%02Xv%08Xd%08X", idev->id_format,
171 		       idev->id_vendor, idev->id_device);
172 }
173 
174 ipack_device_attr(id_format, "0x%hhx\n");
175 
176 static DEVICE_ATTR_RO(id);
177 static DEVICE_ATTR_RO(id_device);
178 static DEVICE_ATTR_RO(id_format);
179 static DEVICE_ATTR_RO(id_vendor);
180 static DEVICE_ATTR_RO(modalias);
181 
182 static struct attribute *ipack_attrs[] = {
183 	&dev_attr_id.attr,
184 	&dev_attr_id_device.attr,
185 	&dev_attr_id_format.attr,
186 	&dev_attr_id_vendor.attr,
187 	&dev_attr_modalias.attr,
188 	NULL,
189 };
190 ATTRIBUTE_GROUPS(ipack);
191 
192 static struct bus_type ipack_bus_type = {
193 	.name      = "ipack",
194 	.probe     = ipack_bus_probe,
195 	.match     = ipack_bus_match,
196 	.remove    = ipack_bus_remove,
197 	.dev_groups = ipack_groups,
198 	.uevent	   = ipack_uevent,
199 };
200 
201 struct ipack_bus_device *ipack_bus_register(struct device *parent, int slots,
202 					    const struct ipack_bus_ops *ops,
203 					    struct module *owner)
204 {
205 	int bus_nr;
206 	struct ipack_bus_device *bus;
207 
208 	bus = kzalloc(sizeof(*bus), GFP_KERNEL);
209 	if (!bus)
210 		return NULL;
211 
212 	bus_nr = ida_simple_get(&ipack_ida, 0, 0, GFP_KERNEL);
213 	if (bus_nr < 0) {
214 		kfree(bus);
215 		return NULL;
216 	}
217 
218 	bus->bus_nr = bus_nr;
219 	bus->parent = parent;
220 	bus->slots = slots;
221 	bus->ops = ops;
222 	bus->owner = owner;
223 	return bus;
224 }
225 EXPORT_SYMBOL_GPL(ipack_bus_register);
226 
227 static int ipack_unregister_bus_member(struct device *dev, void *data)
228 {
229 	struct ipack_device *idev = to_ipack_dev(dev);
230 	struct ipack_bus_device *bus = data;
231 
232 	if (idev->bus == bus)
233 		ipack_device_del(idev);
234 
235 	return 1;
236 }
237 
238 int ipack_bus_unregister(struct ipack_bus_device *bus)
239 {
240 	bus_for_each_dev(&ipack_bus_type, NULL, bus,
241 		ipack_unregister_bus_member);
242 	ida_simple_remove(&ipack_ida, bus->bus_nr);
243 	kfree(bus);
244 	return 0;
245 }
246 EXPORT_SYMBOL_GPL(ipack_bus_unregister);
247 
248 int ipack_driver_register(struct ipack_driver *edrv, struct module *owner,
249 			  const char *name)
250 {
251 	if (!edrv->ops->probe)
252 		return -EINVAL;
253 
254 	edrv->driver.owner = owner;
255 	edrv->driver.name = name;
256 	edrv->driver.bus = &ipack_bus_type;
257 	return driver_register(&edrv->driver);
258 }
259 EXPORT_SYMBOL_GPL(ipack_driver_register);
260 
261 void ipack_driver_unregister(struct ipack_driver *edrv)
262 {
263 	driver_unregister(&edrv->driver);
264 }
265 EXPORT_SYMBOL_GPL(ipack_driver_unregister);
266 
267 static u16 ipack_crc_byte(u16 crc, u8 c)
268 {
269 	int i;
270 
271 	crc ^= c << 8;
272 	for (i = 0; i < 8; i++)
273 		crc = (crc << 1) ^ ((crc & 0x8000) ? 0x1021 : 0);
274 	return crc;
275 }
276 
277 /*
278  * The algorithm in lib/crc-ccitt.c does not seem to apply since it uses the
279  * opposite bit ordering.
280  */
281 static u8 ipack_calc_crc1(struct ipack_device *dev)
282 {
283 	u8 c;
284 	u16 crc;
285 	unsigned int i;
286 
287 	crc = 0xffff;
288 	for (i = 0; i < dev->id_avail; i++) {
289 		c = (i != 11) ? dev->id[i] : 0;
290 		crc = ipack_crc_byte(crc, c);
291 	}
292 	crc = ~crc;
293 	return crc & 0xff;
294 }
295 
296 static u16 ipack_calc_crc2(struct ipack_device *dev)
297 {
298 	u8 c;
299 	u16 crc;
300 	unsigned int i;
301 
302 	crc = 0xffff;
303 	for (i = 0; i < dev->id_avail; i++) {
304 		c = ((i != 0x18) && (i != 0x19)) ? dev->id[i] : 0;
305 		crc = ipack_crc_byte(crc, c);
306 	}
307 	crc = ~crc;
308 	return crc;
309 }
310 
311 static void ipack_parse_id1(struct ipack_device *dev)
312 {
313 	u8 *id = dev->id;
314 	u8 crc;
315 
316 	dev->id_vendor = id[4];
317 	dev->id_device = id[5];
318 	dev->speed_8mhz = 1;
319 	dev->speed_32mhz = (id[7] == 'H');
320 	crc = ipack_calc_crc1(dev);
321 	dev->id_crc_correct = (crc == id[11]);
322 	if (!dev->id_crc_correct) {
323 		dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
324 				id[11], crc);
325 	}
326 }
327 
328 static void ipack_parse_id2(struct ipack_device *dev)
329 {
330 	__be16 *id = (__be16 *) dev->id;
331 	u16 flags, crc;
332 
333 	dev->id_vendor = ((be16_to_cpu(id[3]) & 0xff) << 16)
334 			 + be16_to_cpu(id[4]);
335 	dev->id_device = be16_to_cpu(id[5]);
336 	flags = be16_to_cpu(id[10]);
337 	dev->speed_8mhz = !!(flags & 2);
338 	dev->speed_32mhz = !!(flags & 4);
339 	crc = ipack_calc_crc2(dev);
340 	dev->id_crc_correct = (crc == be16_to_cpu(id[12]));
341 	if (!dev->id_crc_correct) {
342 		dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
343 				id[11], crc);
344 	}
345 }
346 
347 static int ipack_device_read_id(struct ipack_device *dev)
348 {
349 	u8 __iomem *idmem;
350 	int i;
351 	int ret = 0;
352 
353 	idmem = ioremap(dev->region[IPACK_ID_SPACE].start,
354 			dev->region[IPACK_ID_SPACE].size);
355 	if (!idmem) {
356 		dev_err(&dev->dev, "error mapping memory\n");
357 		return -ENOMEM;
358 	}
359 
360 	/* Determine ID PROM Data Format.  If we find the ids "IPAC" or "IPAH"
361 	 * we are dealing with a IndustryPack  format 1 device.  If we detect
362 	 * "VITA4 " (16 bit big endian formatted) we are dealing with a
363 	 * IndustryPack format 2 device */
364 	if ((ioread8(idmem + 1) == 'I') &&
365 			(ioread8(idmem + 3) == 'P') &&
366 			(ioread8(idmem + 5) == 'A') &&
367 			((ioread8(idmem + 7) == 'C') ||
368 			 (ioread8(idmem + 7) == 'H'))) {
369 		dev->id_format = IPACK_ID_VERSION_1;
370 		dev->id_avail = ioread8(idmem + 0x15);
371 		if ((dev->id_avail < 0x0c) || (dev->id_avail > 0x40)) {
372 			dev_warn(&dev->dev, "invalid id size");
373 			dev->id_avail = 0x0c;
374 		}
375 	} else if ((ioread8(idmem + 0) == 'I') &&
376 			(ioread8(idmem + 1) == 'V') &&
377 			(ioread8(idmem + 2) == 'A') &&
378 			(ioread8(idmem + 3) == 'T') &&
379 			(ioread8(idmem + 4) == ' ') &&
380 			(ioread8(idmem + 5) == '4')) {
381 		dev->id_format = IPACK_ID_VERSION_2;
382 		dev->id_avail = ioread16be(idmem + 0x16);
383 		if ((dev->id_avail < 0x1a) || (dev->id_avail > 0x40)) {
384 			dev_warn(&dev->dev, "invalid id size");
385 			dev->id_avail = 0x1a;
386 		}
387 	} else {
388 		dev->id_format = IPACK_ID_VERSION_INVALID;
389 		dev->id_avail = 0;
390 	}
391 
392 	if (!dev->id_avail) {
393 		ret = -ENODEV;
394 		goto out;
395 	}
396 
397 	/* Obtain the amount of memory required to store a copy of the complete
398 	 * ID ROM contents */
399 	dev->id = kmalloc(dev->id_avail, GFP_KERNEL);
400 	if (!dev->id) {
401 		ret = -ENOMEM;
402 		goto out;
403 	}
404 	for (i = 0; i < dev->id_avail; i++) {
405 		if (dev->id_format == IPACK_ID_VERSION_1)
406 			dev->id[i] = ioread8(idmem + (i << 1) + 1);
407 		else
408 			dev->id[i] = ioread8(idmem + i);
409 	}
410 
411 	/* now we can finally work with the copy */
412 	switch (dev->id_format) {
413 	case IPACK_ID_VERSION_1:
414 		ipack_parse_id1(dev);
415 		break;
416 	case IPACK_ID_VERSION_2:
417 		ipack_parse_id2(dev);
418 		break;
419 	}
420 
421 out:
422 	iounmap(idmem);
423 
424 	return ret;
425 }
426 
427 int ipack_device_init(struct ipack_device *dev)
428 {
429 	int ret;
430 
431 	dev->dev.bus = &ipack_bus_type;
432 	dev->dev.release = ipack_device_release;
433 	dev->dev.parent = dev->bus->parent;
434 	dev_set_name(&dev->dev,
435 		     "ipack-dev.%u.%u", dev->bus->bus_nr, dev->slot);
436 	device_initialize(&dev->dev);
437 
438 	if (dev->bus->ops->set_clockrate(dev, 8))
439 		dev_warn(&dev->dev, "failed to switch to 8 MHz operation for reading of device ID.\n");
440 	if (dev->bus->ops->reset_timeout(dev))
441 		dev_warn(&dev->dev, "failed to reset potential timeout.");
442 
443 	ret = ipack_device_read_id(dev);
444 	if (ret < 0) {
445 		dev_err(&dev->dev, "error reading device id section.\n");
446 		return ret;
447 	}
448 
449 	/* if the device supports 32 MHz operation, use it. */
450 	if (dev->speed_32mhz) {
451 		ret = dev->bus->ops->set_clockrate(dev, 32);
452 		if (ret < 0)
453 			dev_err(&dev->dev, "failed to switch to 32 MHz operation.\n");
454 	}
455 
456 	return 0;
457 }
458 EXPORT_SYMBOL_GPL(ipack_device_init);
459 
460 int ipack_device_add(struct ipack_device *dev)
461 {
462 	return device_add(&dev->dev);
463 }
464 EXPORT_SYMBOL_GPL(ipack_device_add);
465 
466 void ipack_device_del(struct ipack_device *dev)
467 {
468 	device_del(&dev->dev);
469 	ipack_put_device(dev);
470 }
471 EXPORT_SYMBOL_GPL(ipack_device_del);
472 
473 void ipack_get_device(struct ipack_device *dev)
474 {
475 	get_device(&dev->dev);
476 }
477 EXPORT_SYMBOL_GPL(ipack_get_device);
478 
479 void ipack_put_device(struct ipack_device *dev)
480 {
481 	put_device(&dev->dev);
482 }
483 EXPORT_SYMBOL_GPL(ipack_put_device);
484 
485 static int __init ipack_init(void)
486 {
487 	ida_init(&ipack_ida);
488 	return bus_register(&ipack_bus_type);
489 }
490 
491 static void __exit ipack_exit(void)
492 {
493 	bus_unregister(&ipack_bus_type);
494 	ida_destroy(&ipack_ida);
495 }
496 
497 module_init(ipack_init);
498 module_exit(ipack_exit);
499 
500 MODULE_AUTHOR("Samuel Iglesias Gonsalvez <siglesias@igalia.com>");
501 MODULE_LICENSE("GPL");
502 MODULE_DESCRIPTION("Industry-pack bus core");
503