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
18static DEFINE_IDA(ipack_ida);
19
20static 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
27static inline const struct ipack_device_id *
28ipack_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
39static const struct ipack_device_id *
40ipack_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
52static 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
62static 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
70static void 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
79static int ipack_uevent(const struct device *dev, struct kobj_uevent_env *env)
80{
81	const struct ipack_device *idev;
82
83	if (!dev)
84		return -ENODEV;
85
86	idev = to_ipack_dev(dev);
87
88	if (add_uevent_var(env,
89			   "MODALIAS=ipack:f%02Xv%08Xd%08X", idev->id_format,
90			   idev->id_vendor, idev->id_device))
91		return -ENOMEM;
92
93	return 0;
94}
95
96#define ipack_device_attr(field, format_string)				\
97static ssize_t								\
98field##_show(struct device *dev, struct device_attribute *attr,		\
99		char *buf)						\
100{									\
101	struct ipack_device *idev = to_ipack_dev(dev);			\
102	return sprintf(buf, format_string, idev->field);		\
103}
104
105static ssize_t id_show(struct device *dev,
106		       struct device_attribute *attr, char *buf)
107{
108	unsigned int i, c, l, s;
109	struct ipack_device *idev = to_ipack_dev(dev);
110
111
112	switch (idev->id_format) {
113	case IPACK_ID_VERSION_1:
114		l = 0x7; s = 1; break;
115	case IPACK_ID_VERSION_2:
116		l = 0xf; s = 2; break;
117	default:
118		return -EIO;
119	}
120	c = 0;
121	for (i = 0; i < idev->id_avail; i++) {
122		if (i > 0) {
123			if ((i & l) == 0)
124				buf[c++] = '\n';
125			else if ((i & s) == 0)
126				buf[c++] = ' ';
127		}
128		sprintf(&buf[c], "%02x", idev->id[i]);
129		c += 2;
130	}
131	buf[c++] = '\n';
132	return c;
133}
134
135static ssize_t
136id_vendor_show(struct device *dev, struct device_attribute *attr, char *buf)
137{
138	struct ipack_device *idev = to_ipack_dev(dev);
139	switch (idev->id_format) {
140	case IPACK_ID_VERSION_1:
141		return sprintf(buf, "0x%02x\n", idev->id_vendor);
142	case IPACK_ID_VERSION_2:
143		return sprintf(buf, "0x%06x\n", idev->id_vendor);
144	default:
145		return -EIO;
146	}
147}
148
149static ssize_t
150id_device_show(struct device *dev, struct device_attribute *attr, char *buf)
151{
152	struct ipack_device *idev = to_ipack_dev(dev);
153	switch (idev->id_format) {
154	case IPACK_ID_VERSION_1:
155		return sprintf(buf, "0x%02x\n", idev->id_device);
156	case IPACK_ID_VERSION_2:
157		return sprintf(buf, "0x%04x\n", idev->id_device);
158	default:
159		return -EIO;
160	}
161}
162
163static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
164			     char *buf)
165{
166	struct ipack_device *idev = to_ipack_dev(dev);
167
168	return sprintf(buf, "ipac:f%02Xv%08Xd%08X", idev->id_format,
169		       idev->id_vendor, idev->id_device);
170}
171
172ipack_device_attr(id_format, "0x%hhx\n");
173
174static DEVICE_ATTR_RO(id);
175static DEVICE_ATTR_RO(id_device);
176static DEVICE_ATTR_RO(id_format);
177static DEVICE_ATTR_RO(id_vendor);
178static DEVICE_ATTR_RO(modalias);
179
180static struct attribute *ipack_attrs[] = {
181	&dev_attr_id.attr,
182	&dev_attr_id_device.attr,
183	&dev_attr_id_format.attr,
184	&dev_attr_id_vendor.attr,
185	&dev_attr_modalias.attr,
186	NULL,
187};
188ATTRIBUTE_GROUPS(ipack);
189
190static const struct bus_type ipack_bus_type = {
191	.name      = "ipack",
192	.probe     = ipack_bus_probe,
193	.match     = ipack_bus_match,
194	.remove    = ipack_bus_remove,
195	.dev_groups = ipack_groups,
196	.uevent	   = ipack_uevent,
197};
198
199struct ipack_bus_device *ipack_bus_register(struct device *parent, int slots,
200					    const struct ipack_bus_ops *ops,
201					    struct module *owner)
202{
203	int bus_nr;
204	struct ipack_bus_device *bus;
205
206	bus = kzalloc(sizeof(*bus), GFP_KERNEL);
207	if (!bus)
208		return NULL;
209
210	bus_nr = ida_alloc(&ipack_ida, GFP_KERNEL);
211	if (bus_nr < 0) {
212		kfree(bus);
213		return NULL;
214	}
215
216	bus->bus_nr = bus_nr;
217	bus->parent = parent;
218	bus->slots = slots;
219	bus->ops = ops;
220	bus->owner = owner;
221	return bus;
222}
223EXPORT_SYMBOL_GPL(ipack_bus_register);
224
225static int ipack_unregister_bus_member(struct device *dev, void *data)
226{
227	struct ipack_device *idev = to_ipack_dev(dev);
228	struct ipack_bus_device *bus = data;
229
230	if (idev->bus == bus)
231		ipack_device_del(idev);
232
233	return 1;
234}
235
236int ipack_bus_unregister(struct ipack_bus_device *bus)
237{
238	bus_for_each_dev(&ipack_bus_type, NULL, bus,
239		ipack_unregister_bus_member);
240	ida_free(&ipack_ida, bus->bus_nr);
241	kfree(bus);
242	return 0;
243}
244EXPORT_SYMBOL_GPL(ipack_bus_unregister);
245
246int ipack_driver_register(struct ipack_driver *edrv, struct module *owner,
247			  const char *name)
248{
249	if (!edrv->ops->probe)
250		return -EINVAL;
251
252	edrv->driver.owner = owner;
253	edrv->driver.name = name;
254	edrv->driver.bus = &ipack_bus_type;
255	return driver_register(&edrv->driver);
256}
257EXPORT_SYMBOL_GPL(ipack_driver_register);
258
259void ipack_driver_unregister(struct ipack_driver *edrv)
260{
261	driver_unregister(&edrv->driver);
262}
263EXPORT_SYMBOL_GPL(ipack_driver_unregister);
264
265static u16 ipack_crc_byte(u16 crc, u8 c)
266{
267	int i;
268
269	crc ^= c << 8;
270	for (i = 0; i < 8; i++)
271		crc = (crc << 1) ^ ((crc & 0x8000) ? 0x1021 : 0);
272	return crc;
273}
274
275/*
276 * The algorithm in lib/crc-ccitt.c does not seem to apply since it uses the
277 * opposite bit ordering.
278 */
279static u8 ipack_calc_crc1(struct ipack_device *dev)
280{
281	u8 c;
282	u16 crc;
283	unsigned int i;
284
285	crc = 0xffff;
286	for (i = 0; i < dev->id_avail; i++) {
287		c = (i != 11) ? dev->id[i] : 0;
288		crc = ipack_crc_byte(crc, c);
289	}
290	crc = ~crc;
291	return crc & 0xff;
292}
293
294static u16 ipack_calc_crc2(struct ipack_device *dev)
295{
296	u8 c;
297	u16 crc;
298	unsigned int i;
299
300	crc = 0xffff;
301	for (i = 0; i < dev->id_avail; i++) {
302		c = ((i != 0x18) && (i != 0x19)) ? dev->id[i] : 0;
303		crc = ipack_crc_byte(crc, c);
304	}
305	crc = ~crc;
306	return crc;
307}
308
309static void ipack_parse_id1(struct ipack_device *dev)
310{
311	u8 *id = dev->id;
312	u8 crc;
313
314	dev->id_vendor = id[4];
315	dev->id_device = id[5];
316	dev->speed_8mhz = 1;
317	dev->speed_32mhz = (id[7] == 'H');
318	crc = ipack_calc_crc1(dev);
319	dev->id_crc_correct = (crc == id[11]);
320	if (!dev->id_crc_correct) {
321		dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
322				id[11], crc);
323	}
324}
325
326static void ipack_parse_id2(struct ipack_device *dev)
327{
328	__be16 *id = (__be16 *) dev->id;
329	u16 flags, crc;
330
331	dev->id_vendor = ((be16_to_cpu(id[3]) & 0xff) << 16)
332			 + be16_to_cpu(id[4]);
333	dev->id_device = be16_to_cpu(id[5]);
334	flags = be16_to_cpu(id[10]);
335	dev->speed_8mhz = !!(flags & 2);
336	dev->speed_32mhz = !!(flags & 4);
337	crc = ipack_calc_crc2(dev);
338	dev->id_crc_correct = (crc == be16_to_cpu(id[12]));
339	if (!dev->id_crc_correct) {
340		dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
341				id[11], crc);
342	}
343}
344
345static int ipack_device_read_id(struct ipack_device *dev)
346{
347	u8 __iomem *idmem;
348	int i;
349	int ret = 0;
350
351	idmem = ioremap(dev->region[IPACK_ID_SPACE].start,
352			dev->region[IPACK_ID_SPACE].size);
353	if (!idmem) {
354		dev_err(&dev->dev, "error mapping memory\n");
355		return -ENOMEM;
356	}
357
358	/* Determine ID PROM Data Format.  If we find the ids "IPAC" or "IPAH"
359	 * we are dealing with a IndustryPack  format 1 device.  If we detect
360	 * "VITA4 " (16 bit big endian formatted) we are dealing with a
361	 * IndustryPack format 2 device */
362	if ((ioread8(idmem + 1) == 'I') &&
363			(ioread8(idmem + 3) == 'P') &&
364			(ioread8(idmem + 5) == 'A') &&
365			((ioread8(idmem + 7) == 'C') ||
366			 (ioread8(idmem + 7) == 'H'))) {
367		dev->id_format = IPACK_ID_VERSION_1;
368		dev->id_avail = ioread8(idmem + 0x15);
369		if ((dev->id_avail < 0x0c) || (dev->id_avail > 0x40)) {
370			dev_warn(&dev->dev, "invalid id size");
371			dev->id_avail = 0x0c;
372		}
373	} else if ((ioread8(idmem + 0) == 'I') &&
374			(ioread8(idmem + 1) == 'V') &&
375			(ioread8(idmem + 2) == 'A') &&
376			(ioread8(idmem + 3) == 'T') &&
377			(ioread8(idmem + 4) == ' ') &&
378			(ioread8(idmem + 5) == '4')) {
379		dev->id_format = IPACK_ID_VERSION_2;
380		dev->id_avail = ioread16be(idmem + 0x16);
381		if ((dev->id_avail < 0x1a) || (dev->id_avail > 0x40)) {
382			dev_warn(&dev->dev, "invalid id size");
383			dev->id_avail = 0x1a;
384		}
385	} else {
386		dev->id_format = IPACK_ID_VERSION_INVALID;
387		dev->id_avail = 0;
388	}
389
390	if (!dev->id_avail) {
391		ret = -ENODEV;
392		goto out;
393	}
394
395	/* Obtain the amount of memory required to store a copy of the complete
396	 * ID ROM contents */
397	dev->id = kmalloc(dev->id_avail, GFP_KERNEL);
398	if (!dev->id) {
399		ret = -ENOMEM;
400		goto out;
401	}
402	for (i = 0; i < dev->id_avail; i++) {
403		if (dev->id_format == IPACK_ID_VERSION_1)
404			dev->id[i] = ioread8(idmem + (i << 1) + 1);
405		else
406			dev->id[i] = ioread8(idmem + i);
407	}
408
409	/* now we can finally work with the copy */
410	switch (dev->id_format) {
411	case IPACK_ID_VERSION_1:
412		ipack_parse_id1(dev);
413		break;
414	case IPACK_ID_VERSION_2:
415		ipack_parse_id2(dev);
416		break;
417	}
418
419out:
420	iounmap(idmem);
421
422	return ret;
423}
424
425int ipack_device_init(struct ipack_device *dev)
426{
427	int ret;
428
429	dev->dev.bus = &ipack_bus_type;
430	dev->dev.release = ipack_device_release;
431	dev->dev.parent = dev->bus->parent;
432	ret = dev_set_name(&dev->dev,
433		     "ipack-dev.%u.%u", dev->bus->bus_nr, dev->slot);
434	if (ret)
435		return ret;
436
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}
459EXPORT_SYMBOL_GPL(ipack_device_init);
460
461int ipack_device_add(struct ipack_device *dev)
462{
463	return device_add(&dev->dev);
464}
465EXPORT_SYMBOL_GPL(ipack_device_add);
466
467void ipack_device_del(struct ipack_device *dev)
468{
469	device_del(&dev->dev);
470	ipack_put_device(dev);
471}
472EXPORT_SYMBOL_GPL(ipack_device_del);
473
474void ipack_get_device(struct ipack_device *dev)
475{
476	get_device(&dev->dev);
477}
478EXPORT_SYMBOL_GPL(ipack_get_device);
479
480void ipack_put_device(struct ipack_device *dev)
481{
482	put_device(&dev->dev);
483}
484EXPORT_SYMBOL_GPL(ipack_put_device);
485
486static int __init ipack_init(void)
487{
488	ida_init(&ipack_ida);
489	return bus_register(&ipack_bus_type);
490}
491
492static void __exit ipack_exit(void)
493{
494	bus_unregister(&ipack_bus_type);
495	ida_destroy(&ipack_ida);
496}
497
498module_init(ipack_init);
499module_exit(ipack_exit);
500
501MODULE_AUTHOR("Samuel Iglesias Gonsalvez <siglesias@igalia.com>");
502MODULE_LICENSE("GPL");
503MODULE_DESCRIPTION("Industry-pack bus core");
504