xref: /linux/drivers/ipack/ipack.c (revision b0f84a84fff180718995b1269da2988e5b28be42)
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 	if (!drv->ops->probe)
68 		return -EINVAL;
69 
70 	return drv->ops->probe(dev);
71 }
72 
73 static int ipack_bus_remove(struct device *device)
74 {
75 	struct ipack_device *dev = to_ipack_dev(device);
76 	struct ipack_driver *drv = to_ipack_driver(device->driver);
77 
78 	if (!drv->ops->remove)
79 		return -EINVAL;
80 
81 	drv->ops->remove(dev);
82 	return 0;
83 }
84 
85 static int ipack_uevent(struct device *dev, struct kobj_uevent_env *env)
86 {
87 	struct ipack_device *idev;
88 
89 	if (!dev)
90 		return -ENODEV;
91 
92 	idev = to_ipack_dev(dev);
93 
94 	if (add_uevent_var(env,
95 			   "MODALIAS=ipack:f%02Xv%08Xd%08X", idev->id_format,
96 			   idev->id_vendor, idev->id_device))
97 		return -ENOMEM;
98 
99 	return 0;
100 }
101 
102 #define ipack_device_attr(field, format_string)				\
103 static ssize_t								\
104 field##_show(struct device *dev, struct device_attribute *attr,		\
105 		char *buf)						\
106 {									\
107 	struct ipack_device *idev = to_ipack_dev(dev);			\
108 	return sprintf(buf, format_string, idev->field);		\
109 }
110 
111 static ssize_t id_show(struct device *dev,
112 		       struct device_attribute *attr, char *buf)
113 {
114 	unsigned int i, c, l, s;
115 	struct ipack_device *idev = to_ipack_dev(dev);
116 
117 
118 	switch (idev->id_format) {
119 	case IPACK_ID_VERSION_1:
120 		l = 0x7; s = 1; break;
121 	case IPACK_ID_VERSION_2:
122 		l = 0xf; s = 2; break;
123 	default:
124 		return -EIO;
125 	}
126 	c = 0;
127 	for (i = 0; i < idev->id_avail; i++) {
128 		if (i > 0) {
129 			if ((i & l) == 0)
130 				buf[c++] = '\n';
131 			else if ((i & s) == 0)
132 				buf[c++] = ' ';
133 		}
134 		sprintf(&buf[c], "%02x", idev->id[i]);
135 		c += 2;
136 	}
137 	buf[c++] = '\n';
138 	return c;
139 }
140 
141 static ssize_t
142 id_vendor_show(struct device *dev, struct device_attribute *attr, char *buf)
143 {
144 	struct ipack_device *idev = to_ipack_dev(dev);
145 	switch (idev->id_format) {
146 	case IPACK_ID_VERSION_1:
147 		return sprintf(buf, "0x%02x\n", idev->id_vendor);
148 	case IPACK_ID_VERSION_2:
149 		return sprintf(buf, "0x%06x\n", idev->id_vendor);
150 	default:
151 		return -EIO;
152 	}
153 }
154 
155 static ssize_t
156 id_device_show(struct device *dev, struct device_attribute *attr, char *buf)
157 {
158 	struct ipack_device *idev = to_ipack_dev(dev);
159 	switch (idev->id_format) {
160 	case IPACK_ID_VERSION_1:
161 		return sprintf(buf, "0x%02x\n", idev->id_device);
162 	case IPACK_ID_VERSION_2:
163 		return sprintf(buf, "0x%04x\n", idev->id_device);
164 	default:
165 		return -EIO;
166 	}
167 }
168 
169 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
170 			     char *buf)
171 {
172 	struct ipack_device *idev = to_ipack_dev(dev);
173 
174 	return sprintf(buf, "ipac:f%02Xv%08Xd%08X", idev->id_format,
175 		       idev->id_vendor, idev->id_device);
176 }
177 
178 ipack_device_attr(id_format, "0x%hhx\n");
179 
180 static DEVICE_ATTR_RO(id);
181 static DEVICE_ATTR_RO(id_device);
182 static DEVICE_ATTR_RO(id_format);
183 static DEVICE_ATTR_RO(id_vendor);
184 static DEVICE_ATTR_RO(modalias);
185 
186 static struct attribute *ipack_attrs[] = {
187 	&dev_attr_id.attr,
188 	&dev_attr_id_device.attr,
189 	&dev_attr_id_format.attr,
190 	&dev_attr_id_vendor.attr,
191 	&dev_attr_modalias.attr,
192 	NULL,
193 };
194 ATTRIBUTE_GROUPS(ipack);
195 
196 static struct bus_type ipack_bus_type = {
197 	.name      = "ipack",
198 	.probe     = ipack_bus_probe,
199 	.match     = ipack_bus_match,
200 	.remove    = ipack_bus_remove,
201 	.dev_groups = ipack_groups,
202 	.uevent	   = ipack_uevent,
203 };
204 
205 struct ipack_bus_device *ipack_bus_register(struct device *parent, int slots,
206 					    const struct ipack_bus_ops *ops,
207 					    struct module *owner)
208 {
209 	int bus_nr;
210 	struct ipack_bus_device *bus;
211 
212 	bus = kzalloc(sizeof(*bus), GFP_KERNEL);
213 	if (!bus)
214 		return NULL;
215 
216 	bus_nr = ida_simple_get(&ipack_ida, 0, 0, GFP_KERNEL);
217 	if (bus_nr < 0) {
218 		kfree(bus);
219 		return NULL;
220 	}
221 
222 	bus->bus_nr = bus_nr;
223 	bus->parent = parent;
224 	bus->slots = slots;
225 	bus->ops = ops;
226 	bus->owner = owner;
227 	return bus;
228 }
229 EXPORT_SYMBOL_GPL(ipack_bus_register);
230 
231 static int ipack_unregister_bus_member(struct device *dev, void *data)
232 {
233 	struct ipack_device *idev = to_ipack_dev(dev);
234 	struct ipack_bus_device *bus = data;
235 
236 	if (idev->bus == bus)
237 		ipack_device_del(idev);
238 
239 	return 1;
240 }
241 
242 int ipack_bus_unregister(struct ipack_bus_device *bus)
243 {
244 	bus_for_each_dev(&ipack_bus_type, NULL, bus,
245 		ipack_unregister_bus_member);
246 	ida_simple_remove(&ipack_ida, bus->bus_nr);
247 	kfree(bus);
248 	return 0;
249 }
250 EXPORT_SYMBOL_GPL(ipack_bus_unregister);
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 }
260 EXPORT_SYMBOL_GPL(ipack_driver_register);
261 
262 void ipack_driver_unregister(struct ipack_driver *edrv)
263 {
264 	driver_unregister(&edrv->driver);
265 }
266 EXPORT_SYMBOL_GPL(ipack_driver_unregister);
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 	idmem = ioremap(dev->region[IPACK_ID_SPACE].start,
355 			dev->region[IPACK_ID_SPACE].size);
356 	if (!idmem) {
357 		dev_err(&dev->dev, "error mapping memory\n");
358 		return -ENOMEM;
359 	}
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'))) {
370 		dev->id_format = IPACK_ID_VERSION_1;
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')) {
382 		dev->id_format = IPACK_ID_VERSION_2;
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 {
389 		dev->id_format = IPACK_ID_VERSION_INVALID;
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 		ret = -ENOMEM;
403 		goto out;
404 	}
405 	for (i = 0; i < dev->id_avail; i++) {
406 		if (dev->id_format == IPACK_ID_VERSION_1)
407 			dev->id[i] = ioread8(idmem + (i << 1) + 1);
408 		else
409 			dev->id[i] = ioread8(idmem + i);
410 	}
411 
412 	/* now we can finally work with the copy */
413 	switch (dev->id_format) {
414 	case IPACK_ID_VERSION_1:
415 		ipack_parse_id1(dev);
416 		break;
417 	case IPACK_ID_VERSION_2:
418 		ipack_parse_id2(dev);
419 		break;
420 	}
421 
422 out:
423 	iounmap(idmem);
424 
425 	return ret;
426 }
427 
428 int ipack_device_init(struct ipack_device *dev)
429 {
430 	int ret;
431 
432 	dev->dev.bus = &ipack_bus_type;
433 	dev->dev.release = ipack_device_release;
434 	dev->dev.parent = dev->bus->parent;
435 	dev_set_name(&dev->dev,
436 		     "ipack-dev.%u.%u", dev->bus->bus_nr, dev->slot);
437 	device_initialize(&dev->dev);
438 
439 	if (dev->bus->ops->set_clockrate(dev, 8))
440 		dev_warn(&dev->dev, "failed to switch to 8 MHz operation for reading of device ID.\n");
441 	if (dev->bus->ops->reset_timeout(dev))
442 		dev_warn(&dev->dev, "failed to reset potential timeout.");
443 
444 	ret = ipack_device_read_id(dev);
445 	if (ret < 0) {
446 		dev_err(&dev->dev, "error reading device id section.\n");
447 		return ret;
448 	}
449 
450 	/* if the device supports 32 MHz operation, use it. */
451 	if (dev->speed_32mhz) {
452 		ret = dev->bus->ops->set_clockrate(dev, 32);
453 		if (ret < 0)
454 			dev_err(&dev->dev, "failed to switch to 32 MHz operation.\n");
455 	}
456 
457 	return 0;
458 }
459 EXPORT_SYMBOL_GPL(ipack_device_init);
460 
461 int ipack_device_add(struct ipack_device *dev)
462 {
463 	return device_add(&dev->dev);
464 }
465 EXPORT_SYMBOL_GPL(ipack_device_add);
466 
467 void ipack_device_del(struct ipack_device *dev)
468 {
469 	device_del(&dev->dev);
470 	ipack_put_device(dev);
471 }
472 EXPORT_SYMBOL_GPL(ipack_device_del);
473 
474 void ipack_get_device(struct ipack_device *dev)
475 {
476 	get_device(&dev->dev);
477 }
478 EXPORT_SYMBOL_GPL(ipack_get_device);
479 
480 void ipack_put_device(struct ipack_device *dev)
481 {
482 	put_device(&dev->dev);
483 }
484 EXPORT_SYMBOL_GPL(ipack_put_device);
485 
486 static int __init ipack_init(void)
487 {
488 	ida_init(&ipack_ida);
489 	return bus_register(&ipack_bus_type);
490 }
491 
492 static void __exit ipack_exit(void)
493 {
494 	bus_unregister(&ipack_bus_type);
495 	ida_destroy(&ipack_ida);
496 }
497 
498 module_init(ipack_init);
499 module_exit(ipack_exit);
500 
501 MODULE_AUTHOR("Samuel Iglesias Gonsalvez <siglesias@igalia.com>");
502 MODULE_LICENSE("GPL");
503 MODULE_DESCRIPTION("Industry-pack bus core");
504