xref: /openbmc/linux/drivers/bus/moxtet.c (revision a44e4f3a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Turris Mox module configuration bus driver
4  *
5  * Copyright (C) 2019 Marek Behun <marek.behun@nic.cz>
6  */
7 
8 #include <dt-bindings/bus/moxtet.h>
9 #include <linux/bitops.h>
10 #include <linux/debugfs.h>
11 #include <linux/interrupt.h>
12 #include <linux/module.h>
13 #include <linux/moxtet.h>
14 #include <linux/mutex.h>
15 #include <linux/of_device.h>
16 #include <linux/of_irq.h>
17 #include <linux/spi/spi.h>
18 
19 /*
20  * @name:	module name for sysfs
21  * @hwirq_base:	base index for IRQ for this module (-1 if no IRQs)
22  * @nirqs:	how many interrupts does the shift register provide
23  * @desc:	module description for kernel log
24  */
25 static const struct {
26 	const char *name;
27 	int hwirq_base;
28 	int nirqs;
29 	const char *desc;
30 } mox_module_table[] = {
31 	/* do not change order of this array! */
32 	{ NULL,		 0,			0, NULL },
33 	{ "sfp",	-1,			0, "MOX D (SFP cage)" },
34 	{ "pci",	MOXTET_IRQ_PCI,		1, "MOX B (Mini-PCIe)" },
35 	{ "topaz",	MOXTET_IRQ_TOPAZ,	1, "MOX C (4 port switch)" },
36 	{ "peridot",	MOXTET_IRQ_PERIDOT(0),	1, "MOX E (8 port switch)" },
37 	{ "usb3",	MOXTET_IRQ_USB3,	2, "MOX F (USB 3.0)" },
38 	{ "pci-bridge",	-1,			0, "MOX G (Mini-PCIe bridge)" },
39 };
40 
41 static inline bool mox_module_known(unsigned int id)
42 {
43 	return id >= TURRIS_MOX_MODULE_FIRST && id <= TURRIS_MOX_MODULE_LAST;
44 }
45 
46 static inline const char *mox_module_name(unsigned int id)
47 {
48 	if (mox_module_known(id))
49 		return mox_module_table[id].name;
50 	else
51 		return "unknown";
52 }
53 
54 #define DEF_MODULE_ATTR(name, fmt, ...)					\
55 static ssize_t								\
56 module_##name##_show(struct device *dev, struct device_attribute *a,	\
57 		     char *buf)						\
58 {									\
59 	struct moxtet_device *mdev = to_moxtet_device(dev);		\
60 	return sprintf(buf, (fmt), __VA_ARGS__);			\
61 }									\
62 static DEVICE_ATTR_RO(module_##name)
63 
64 DEF_MODULE_ATTR(id, "0x%x\n", mdev->id);
65 DEF_MODULE_ATTR(name, "%s\n", mox_module_name(mdev->id));
66 DEF_MODULE_ATTR(description, "%s\n",
67 		mox_module_known(mdev->id) ? mox_module_table[mdev->id].desc
68 					   : "");
69 
70 static struct attribute *moxtet_dev_attrs[] = {
71 	&dev_attr_module_id.attr,
72 	&dev_attr_module_name.attr,
73 	&dev_attr_module_description.attr,
74 	NULL,
75 };
76 
77 static const struct attribute_group moxtet_dev_group = {
78 	.attrs = moxtet_dev_attrs,
79 };
80 
81 static const struct attribute_group *moxtet_dev_groups[] = {
82 	&moxtet_dev_group,
83 	NULL,
84 };
85 
86 static int moxtet_match(struct device *dev, struct device_driver *drv)
87 {
88 	struct moxtet_device *mdev = to_moxtet_device(dev);
89 	struct moxtet_driver *tdrv = to_moxtet_driver(drv);
90 	const enum turris_mox_module_id *t;
91 
92 	if (of_driver_match_device(dev, drv))
93 		return 1;
94 
95 	if (!tdrv->id_table)
96 		return 0;
97 
98 	for (t = tdrv->id_table; *t; ++t)
99 		if (*t == mdev->id)
100 			return 1;
101 
102 	return 0;
103 }
104 
105 struct bus_type moxtet_bus_type = {
106 	.name		= "moxtet",
107 	.dev_groups	= moxtet_dev_groups,
108 	.match		= moxtet_match,
109 };
110 EXPORT_SYMBOL_GPL(moxtet_bus_type);
111 
112 int __moxtet_register_driver(struct module *owner,
113 			     struct moxtet_driver *mdrv)
114 {
115 	mdrv->driver.owner = owner;
116 	mdrv->driver.bus = &moxtet_bus_type;
117 	return driver_register(&mdrv->driver);
118 }
119 EXPORT_SYMBOL_GPL(__moxtet_register_driver);
120 
121 static int moxtet_dev_check(struct device *dev, void *data)
122 {
123 	struct moxtet_device *mdev = to_moxtet_device(dev);
124 	struct moxtet_device *new_dev = data;
125 
126 	if (mdev->moxtet == new_dev->moxtet && mdev->id == new_dev->id &&
127 	    mdev->idx == new_dev->idx)
128 		return -EBUSY;
129 	return 0;
130 }
131 
132 static void moxtet_dev_release(struct device *dev)
133 {
134 	struct moxtet_device *mdev = to_moxtet_device(dev);
135 
136 	put_device(mdev->moxtet->dev);
137 	kfree(mdev);
138 }
139 
140 static struct moxtet_device *
141 moxtet_alloc_device(struct moxtet *moxtet)
142 {
143 	struct moxtet_device *dev;
144 
145 	if (!get_device(moxtet->dev))
146 		return NULL;
147 
148 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
149 	if (!dev) {
150 		put_device(moxtet->dev);
151 		return NULL;
152 	}
153 
154 	dev->moxtet = moxtet;
155 	dev->dev.parent = moxtet->dev;
156 	dev->dev.bus = &moxtet_bus_type;
157 	dev->dev.release = moxtet_dev_release;
158 
159 	device_initialize(&dev->dev);
160 
161 	return dev;
162 }
163 
164 static int moxtet_add_device(struct moxtet_device *dev)
165 {
166 	static DEFINE_MUTEX(add_mutex);
167 	int ret;
168 
169 	if (dev->idx >= TURRIS_MOX_MAX_MODULES || dev->id > 0xf)
170 		return -EINVAL;
171 
172 	dev_set_name(&dev->dev, "moxtet-%s.%u", mox_module_name(dev->id),
173 		     dev->idx);
174 
175 	mutex_lock(&add_mutex);
176 
177 	ret = bus_for_each_dev(&moxtet_bus_type, NULL, dev,
178 			       moxtet_dev_check);
179 	if (ret)
180 		goto done;
181 
182 	ret = device_add(&dev->dev);
183 	if (ret < 0)
184 		dev_err(dev->moxtet->dev, "can't add %s, status %d\n",
185 			dev_name(dev->moxtet->dev), ret);
186 
187 done:
188 	mutex_unlock(&add_mutex);
189 	return ret;
190 }
191 
192 static int __unregister(struct device *dev, void *null)
193 {
194 	if (dev->of_node) {
195 		of_node_clear_flag(dev->of_node, OF_POPULATED);
196 		of_node_put(dev->of_node);
197 	}
198 
199 	device_unregister(dev);
200 
201 	return 0;
202 }
203 
204 static struct moxtet_device *
205 of_register_moxtet_device(struct moxtet *moxtet, struct device_node *nc)
206 {
207 	struct moxtet_device *dev;
208 	u32 val;
209 	int ret;
210 
211 	dev = moxtet_alloc_device(moxtet);
212 	if (!dev) {
213 		dev_err(moxtet->dev,
214 			"Moxtet device alloc error for %pOF\n", nc);
215 		return ERR_PTR(-ENOMEM);
216 	}
217 
218 	ret = of_property_read_u32(nc, "reg", &val);
219 	if (ret) {
220 		dev_err(moxtet->dev, "%pOF has no valid 'reg' property (%d)\n",
221 			nc, ret);
222 		goto err_put;
223 	}
224 
225 	dev->idx = val;
226 
227 	if (dev->idx >= TURRIS_MOX_MAX_MODULES) {
228 		dev_err(moxtet->dev, "%pOF Moxtet address 0x%x out of range\n",
229 			nc, dev->idx);
230 		ret = -EINVAL;
231 		goto err_put;
232 	}
233 
234 	dev->id = moxtet->modules[dev->idx];
235 
236 	if (!dev->id) {
237 		dev_err(moxtet->dev, "%pOF Moxtet address 0x%x is empty\n", nc,
238 			dev->idx);
239 		ret = -ENODEV;
240 		goto err_put;
241 	}
242 
243 	of_node_get(nc);
244 	dev->dev.of_node = nc;
245 
246 	ret = moxtet_add_device(dev);
247 	if (ret) {
248 		dev_err(moxtet->dev,
249 			"Moxtet device register error for %pOF\n", nc);
250 		of_node_put(nc);
251 		goto err_put;
252 	}
253 
254 	return dev;
255 
256 err_put:
257 	put_device(&dev->dev);
258 	return ERR_PTR(ret);
259 }
260 
261 static void of_register_moxtet_devices(struct moxtet *moxtet)
262 {
263 	struct moxtet_device *dev;
264 	struct device_node *nc;
265 
266 	if (!moxtet->dev->of_node)
267 		return;
268 
269 	for_each_available_child_of_node(moxtet->dev->of_node, nc) {
270 		if (of_node_test_and_set_flag(nc, OF_POPULATED))
271 			continue;
272 		dev = of_register_moxtet_device(moxtet, nc);
273 		if (IS_ERR(dev)) {
274 			dev_warn(moxtet->dev,
275 				 "Failed to create Moxtet device for %pOF\n",
276 				 nc);
277 			of_node_clear_flag(nc, OF_POPULATED);
278 		}
279 	}
280 }
281 
282 static void
283 moxtet_register_devices_from_topology(struct moxtet *moxtet)
284 {
285 	struct moxtet_device *dev;
286 	int i, ret;
287 
288 	for (i = 0; i < moxtet->count; ++i) {
289 		dev = moxtet_alloc_device(moxtet);
290 		if (!dev) {
291 			dev_err(moxtet->dev, "Moxtet device %u alloc error\n",
292 				i);
293 			continue;
294 		}
295 
296 		dev->idx = i;
297 		dev->id = moxtet->modules[i];
298 
299 		ret = moxtet_add_device(dev);
300 		if (ret && ret != -EBUSY) {
301 			put_device(&dev->dev);
302 			dev_err(moxtet->dev,
303 				"Moxtet device %u register error: %i\n", i,
304 				ret);
305 		}
306 	}
307 }
308 
309 /*
310  * @nsame:	how many modules with same id are already in moxtet->modules
311  */
312 static int moxtet_set_irq(struct moxtet *moxtet, int idx, int id, int nsame)
313 {
314 	int i, first;
315 	struct moxtet_irqpos *pos;
316 
317 	first = mox_module_table[id].hwirq_base +
318 		nsame * mox_module_table[id].nirqs;
319 
320 	if (first + mox_module_table[id].nirqs > MOXTET_NIRQS)
321 		return -EINVAL;
322 
323 	for (i = 0; i < mox_module_table[id].nirqs; ++i) {
324 		pos = &moxtet->irq.position[first + i];
325 		pos->idx = idx;
326 		pos->bit = i;
327 		moxtet->irq.exists |= BIT(first + i);
328 	}
329 
330 	return 0;
331 }
332 
333 static int moxtet_find_topology(struct moxtet *moxtet)
334 {
335 	u8 buf[TURRIS_MOX_MAX_MODULES];
336 	int cnts[TURRIS_MOX_MODULE_LAST];
337 	int i, ret;
338 
339 	memset(cnts, 0, sizeof(cnts));
340 
341 	ret = spi_read(to_spi_device(moxtet->dev), buf, TURRIS_MOX_MAX_MODULES);
342 	if (ret < 0)
343 		return ret;
344 
345 	if (buf[0] == TURRIS_MOX_CPU_ID_EMMC) {
346 		dev_info(moxtet->dev, "Found MOX A (eMMC CPU) module\n");
347 	} else if (buf[0] == TURRIS_MOX_CPU_ID_SD) {
348 		dev_info(moxtet->dev, "Found MOX A (CPU) module\n");
349 	} else {
350 		dev_err(moxtet->dev, "Invalid Turris MOX A CPU module 0x%02x\n",
351 			buf[0]);
352 		return -ENODEV;
353 	}
354 
355 	moxtet->count = 0;
356 
357 	for (i = 1; i < TURRIS_MOX_MAX_MODULES; ++i) {
358 		int id;
359 
360 		if (buf[i] == 0xff)
361 			break;
362 
363 		id = buf[i] & 0xf;
364 
365 		moxtet->modules[i-1] = id;
366 		++moxtet->count;
367 
368 		if (mox_module_known(id)) {
369 			dev_info(moxtet->dev, "Found %s module\n",
370 				 mox_module_table[id].desc);
371 
372 			if (moxtet_set_irq(moxtet, i-1, id, cnts[id]++) < 0)
373 				dev_err(moxtet->dev,
374 					"  Cannot set IRQ for module %s\n",
375 					mox_module_table[id].desc);
376 		} else {
377 			dev_warn(moxtet->dev,
378 				 "Unknown Moxtet module found (ID 0x%02x)\n",
379 				 id);
380 		}
381 	}
382 
383 	return 0;
384 }
385 
386 static int moxtet_spi_read(struct moxtet *moxtet, u8 *buf)
387 {
388 	struct spi_transfer xfer = {
389 		.rx_buf = buf,
390 		.tx_buf = moxtet->tx,
391 		.len = moxtet->count + 1
392 	};
393 	int ret;
394 
395 	mutex_lock(&moxtet->lock);
396 
397 	ret = spi_sync_transfer(to_spi_device(moxtet->dev), &xfer, 1);
398 
399 	mutex_unlock(&moxtet->lock);
400 
401 	return ret;
402 }
403 
404 int moxtet_device_read(struct device *dev)
405 {
406 	struct moxtet_device *mdev = to_moxtet_device(dev);
407 	struct moxtet *moxtet = mdev->moxtet;
408 	u8 buf[TURRIS_MOX_MAX_MODULES];
409 	int ret;
410 
411 	if (mdev->idx >= moxtet->count)
412 		return -EINVAL;
413 
414 	ret = moxtet_spi_read(moxtet, buf);
415 	if (ret < 0)
416 		return ret;
417 
418 	return buf[mdev->idx + 1] >> 4;
419 }
420 EXPORT_SYMBOL_GPL(moxtet_device_read);
421 
422 int moxtet_device_write(struct device *dev, u8 val)
423 {
424 	struct moxtet_device *mdev = to_moxtet_device(dev);
425 	struct moxtet *moxtet = mdev->moxtet;
426 	int ret;
427 
428 	if (mdev->idx >= moxtet->count)
429 		return -EINVAL;
430 
431 	mutex_lock(&moxtet->lock);
432 
433 	moxtet->tx[moxtet->count - mdev->idx] = val;
434 
435 	ret = spi_write(to_spi_device(moxtet->dev), moxtet->tx,
436 			moxtet->count + 1);
437 
438 	mutex_unlock(&moxtet->lock);
439 
440 	return ret;
441 }
442 EXPORT_SYMBOL_GPL(moxtet_device_write);
443 
444 int moxtet_device_written(struct device *dev)
445 {
446 	struct moxtet_device *mdev = to_moxtet_device(dev);
447 	struct moxtet *moxtet = mdev->moxtet;
448 
449 	if (mdev->idx >= moxtet->count)
450 		return -EINVAL;
451 
452 	return moxtet->tx[moxtet->count - mdev->idx];
453 }
454 EXPORT_SYMBOL_GPL(moxtet_device_written);
455 
456 #ifdef CONFIG_DEBUG_FS
457 static int moxtet_debug_open(struct inode *inode, struct file *file)
458 {
459 	file->private_data = inode->i_private;
460 
461 	return nonseekable_open(inode, file);
462 }
463 
464 static ssize_t input_read(struct file *file, char __user *buf, size_t len,
465 			  loff_t *ppos)
466 {
467 	struct moxtet *moxtet = file->private_data;
468 	u8 bin[TURRIS_MOX_MAX_MODULES];
469 	u8 hex[sizeof(buf) * 2 + 1];
470 	int ret, n;
471 
472 	ret = moxtet_spi_read(moxtet, bin);
473 	if (ret < 0)
474 		return ret;
475 
476 	n = moxtet->count + 1;
477 	bin2hex(hex, bin, n);
478 
479 	hex[2*n] = '\n';
480 
481 	return simple_read_from_buffer(buf, len, ppos, hex, 2*n + 1);
482 }
483 
484 static const struct file_operations input_fops = {
485 	.owner	= THIS_MODULE,
486 	.open	= moxtet_debug_open,
487 	.read	= input_read,
488 	.llseek	= no_llseek,
489 };
490 
491 static ssize_t output_read(struct file *file, char __user *buf, size_t len,
492 			   loff_t *ppos)
493 {
494 	struct moxtet *moxtet = file->private_data;
495 	u8 hex[TURRIS_MOX_MAX_MODULES * 2 + 1];
496 	u8 *p = hex;
497 	int i;
498 
499 	mutex_lock(&moxtet->lock);
500 
501 	for (i = 0; i < moxtet->count; ++i)
502 		p = hex_byte_pack(p, moxtet->tx[moxtet->count - i]);
503 
504 	mutex_unlock(&moxtet->lock);
505 
506 	*p++ = '\n';
507 
508 	return simple_read_from_buffer(buf, len, ppos, hex, p - hex);
509 }
510 
511 static ssize_t output_write(struct file *file, const char __user *buf,
512 			    size_t len, loff_t *ppos)
513 {
514 	struct moxtet *moxtet = file->private_data;
515 	u8 bin[TURRIS_MOX_MAX_MODULES];
516 	u8 hex[sizeof(bin) * 2 + 1];
517 	ssize_t res;
518 	loff_t dummy = 0;
519 	int err, i;
520 
521 	if (len > 2 * moxtet->count + 1 || len < 2 * moxtet->count)
522 		return -EINVAL;
523 
524 	res = simple_write_to_buffer(hex, sizeof(hex), &dummy, buf, len);
525 	if (res < 0)
526 		return res;
527 
528 	if (len % 2 == 1 && hex[len - 1] != '\n')
529 		return -EINVAL;
530 
531 	err = hex2bin(bin, hex, moxtet->count);
532 	if (err < 0)
533 		return -EINVAL;
534 
535 	mutex_lock(&moxtet->lock);
536 
537 	for (i = 0; i < moxtet->count; ++i)
538 		moxtet->tx[moxtet->count - i] = bin[i];
539 
540 	err = spi_write(to_spi_device(moxtet->dev), moxtet->tx,
541 			moxtet->count + 1);
542 
543 	mutex_unlock(&moxtet->lock);
544 
545 	return err < 0 ? err : len;
546 }
547 
548 static const struct file_operations output_fops = {
549 	.owner	= THIS_MODULE,
550 	.open	= moxtet_debug_open,
551 	.read	= output_read,
552 	.write	= output_write,
553 	.llseek	= no_llseek,
554 };
555 
556 static int moxtet_register_debugfs(struct moxtet *moxtet)
557 {
558 	struct dentry *root, *entry;
559 
560 	root = debugfs_create_dir("moxtet", NULL);
561 
562 	if (IS_ERR(root))
563 		return PTR_ERR(root);
564 
565 	entry = debugfs_create_file_unsafe("input", 0444, root, moxtet,
566 					   &input_fops);
567 	if (IS_ERR(entry))
568 		goto err_remove;
569 
570 	entry = debugfs_create_file_unsafe("output", 0644, root, moxtet,
571 					   &output_fops);
572 	if (IS_ERR(entry))
573 		goto err_remove;
574 
575 	moxtet->debugfs_root = root;
576 
577 	return 0;
578 err_remove:
579 	debugfs_remove_recursive(root);
580 	return PTR_ERR(entry);
581 }
582 
583 static void moxtet_unregister_debugfs(struct moxtet *moxtet)
584 {
585 	debugfs_remove_recursive(moxtet->debugfs_root);
586 }
587 #else
588 static inline int moxtet_register_debugfs(struct moxtet *moxtet)
589 {
590 	return 0;
591 }
592 
593 static inline void moxtet_unregister_debugfs(struct moxtet *moxtet)
594 {
595 }
596 #endif
597 
598 static int moxtet_irq_domain_map(struct irq_domain *d, unsigned int irq,
599 				 irq_hw_number_t hw)
600 {
601 	struct moxtet *moxtet = d->host_data;
602 
603 	if (hw >= MOXTET_NIRQS || !(moxtet->irq.exists & BIT(hw))) {
604 		dev_err(moxtet->dev, "Invalid hw irq number\n");
605 		return -EINVAL;
606 	}
607 
608 	irq_set_chip_data(irq, d->host_data);
609 	irq_set_chip_and_handler(irq, &moxtet->irq.chip, handle_level_irq);
610 
611 	return 0;
612 }
613 
614 static int moxtet_irq_domain_xlate(struct irq_domain *d,
615 				   struct device_node *ctrlr,
616 				   const u32 *intspec, unsigned int intsize,
617 				   unsigned long *out_hwirq,
618 				   unsigned int *out_type)
619 {
620 	struct moxtet *moxtet = d->host_data;
621 	int irq;
622 
623 	if (WARN_ON(intsize < 1))
624 		return -EINVAL;
625 
626 	irq = intspec[0];
627 
628 	if (irq >= MOXTET_NIRQS || !(moxtet->irq.exists & BIT(irq)))
629 		return -EINVAL;
630 
631 	*out_hwirq = irq;
632 	*out_type = IRQ_TYPE_NONE;
633 	return 0;
634 }
635 
636 static const struct irq_domain_ops moxtet_irq_domain = {
637 	.map = moxtet_irq_domain_map,
638 	.xlate = moxtet_irq_domain_xlate,
639 };
640 
641 static void moxtet_irq_mask(struct irq_data *d)
642 {
643 	struct moxtet *moxtet = irq_data_get_irq_chip_data(d);
644 
645 	moxtet->irq.masked |= BIT(d->hwirq);
646 }
647 
648 static void moxtet_irq_unmask(struct irq_data *d)
649 {
650 	struct moxtet *moxtet = irq_data_get_irq_chip_data(d);
651 
652 	moxtet->irq.masked &= ~BIT(d->hwirq);
653 }
654 
655 static void moxtet_irq_print_chip(struct irq_data *d, struct seq_file *p)
656 {
657 	struct moxtet *moxtet = irq_data_get_irq_chip_data(d);
658 	struct moxtet_irqpos *pos = &moxtet->irq.position[d->hwirq];
659 	int id;
660 
661 	id = moxtet->modules[pos->idx];
662 
663 	seq_printf(p, " moxtet-%s.%i#%i", mox_module_name(id), pos->idx,
664 		   pos->bit);
665 }
666 
667 static const struct irq_chip moxtet_irq_chip = {
668 	.name			= "moxtet",
669 	.irq_mask		= moxtet_irq_mask,
670 	.irq_unmask		= moxtet_irq_unmask,
671 	.irq_print_chip		= moxtet_irq_print_chip,
672 };
673 
674 static int moxtet_irq_read(struct moxtet *moxtet, unsigned long *map)
675 {
676 	struct moxtet_irqpos *pos = moxtet->irq.position;
677 	u8 buf[TURRIS_MOX_MAX_MODULES];
678 	int i, ret;
679 
680 	ret = moxtet_spi_read(moxtet, buf);
681 	if (ret < 0)
682 		return ret;
683 
684 	*map = 0;
685 
686 	for_each_set_bit(i, &moxtet->irq.exists, MOXTET_NIRQS) {
687 		if (!(buf[pos[i].idx + 1] & BIT(4 + pos[i].bit)))
688 			set_bit(i, map);
689 	}
690 
691 	return 0;
692 }
693 
694 static irqreturn_t moxtet_irq_thread_fn(int irq, void *data)
695 {
696 	struct moxtet *moxtet = data;
697 	unsigned long set;
698 	int nhandled = 0, i, sub_irq, ret;
699 
700 	ret = moxtet_irq_read(moxtet, &set);
701 	if (ret < 0)
702 		goto out;
703 
704 	set &= ~moxtet->irq.masked;
705 
706 	do {
707 		for_each_set_bit(i, &set, MOXTET_NIRQS) {
708 			sub_irq = irq_find_mapping(moxtet->irq.domain, i);
709 			handle_nested_irq(sub_irq);
710 			dev_dbg(moxtet->dev, "%i irq\n", i);
711 			++nhandled;
712 		}
713 
714 		ret = moxtet_irq_read(moxtet, &set);
715 		if (ret < 0)
716 			goto out;
717 
718 		set &= ~moxtet->irq.masked;
719 	} while (set);
720 
721 out:
722 	return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
723 }
724 
725 static void moxtet_irq_free(struct moxtet *moxtet)
726 {
727 	int i, irq;
728 
729 	for (i = 0; i < MOXTET_NIRQS; ++i) {
730 		if (moxtet->irq.exists & BIT(i)) {
731 			irq = irq_find_mapping(moxtet->irq.domain, i);
732 			irq_dispose_mapping(irq);
733 		}
734 	}
735 
736 	irq_domain_remove(moxtet->irq.domain);
737 }
738 
739 static int moxtet_irq_setup(struct moxtet *moxtet)
740 {
741 	int i, ret;
742 
743 	moxtet->irq.domain = irq_domain_add_simple(moxtet->dev->of_node,
744 						   MOXTET_NIRQS, 0,
745 						   &moxtet_irq_domain, moxtet);
746 	if (moxtet->irq.domain == NULL) {
747 		dev_err(moxtet->dev, "Could not add IRQ domain\n");
748 		return -ENOMEM;
749 	}
750 
751 	for (i = 0; i < MOXTET_NIRQS; ++i)
752 		if (moxtet->irq.exists & BIT(i))
753 			irq_create_mapping(moxtet->irq.domain, i);
754 
755 	moxtet->irq.chip = moxtet_irq_chip;
756 	moxtet->irq.masked = ~0;
757 
758 	ret = request_threaded_irq(moxtet->dev_irq, NULL, moxtet_irq_thread_fn,
759 				   IRQF_ONESHOT, "moxtet", moxtet);
760 	if (ret < 0)
761 		goto err_free;
762 
763 	return 0;
764 
765 err_free:
766 	moxtet_irq_free(moxtet);
767 	return ret;
768 }
769 
770 static int moxtet_probe(struct spi_device *spi)
771 {
772 	struct moxtet *moxtet;
773 	int ret;
774 
775 	ret = spi_setup(spi);
776 	if (ret < 0)
777 		return ret;
778 
779 	moxtet = devm_kzalloc(&spi->dev, sizeof(struct moxtet),
780 			      GFP_KERNEL);
781 	if (!moxtet)
782 		return -ENOMEM;
783 
784 	moxtet->dev = &spi->dev;
785 	spi_set_drvdata(spi, moxtet);
786 
787 	mutex_init(&moxtet->lock);
788 
789 	moxtet->dev_irq = of_irq_get(moxtet->dev->of_node, 0);
790 	if (moxtet->dev_irq == -EPROBE_DEFER)
791 		return -EPROBE_DEFER;
792 
793 	if (moxtet->dev_irq <= 0) {
794 		dev_err(moxtet->dev, "No IRQ resource found\n");
795 		return -ENXIO;
796 	}
797 
798 	ret = moxtet_find_topology(moxtet);
799 	if (ret < 0)
800 		return ret;
801 
802 	if (moxtet->irq.exists) {
803 		ret = moxtet_irq_setup(moxtet);
804 		if (ret < 0)
805 			return ret;
806 	}
807 
808 	of_register_moxtet_devices(moxtet);
809 	moxtet_register_devices_from_topology(moxtet);
810 
811 	ret = moxtet_register_debugfs(moxtet);
812 	if (ret < 0)
813 		dev_warn(moxtet->dev, "Failed creating debugfs entries: %i\n",
814 			 ret);
815 
816 	return 0;
817 }
818 
819 static int moxtet_remove(struct spi_device *spi)
820 {
821 	struct moxtet *moxtet = spi_get_drvdata(spi);
822 
823 	free_irq(moxtet->dev_irq, moxtet);
824 
825 	moxtet_irq_free(moxtet);
826 
827 	moxtet_unregister_debugfs(moxtet);
828 
829 	device_for_each_child(moxtet->dev, NULL, __unregister);
830 
831 	mutex_destroy(&moxtet->lock);
832 
833 	return 0;
834 }
835 
836 static const struct of_device_id moxtet_dt_ids[] = {
837 	{ .compatible = "cznic,moxtet" },
838 	{},
839 };
840 MODULE_DEVICE_TABLE(of, moxtet_dt_ids);
841 
842 static struct spi_driver moxtet_spi_driver = {
843 	.driver = {
844 		.name		= "moxtet",
845 		.of_match_table = moxtet_dt_ids,
846 	},
847 	.probe		= moxtet_probe,
848 	.remove		= moxtet_remove,
849 };
850 
851 static int __init moxtet_init(void)
852 {
853 	int ret;
854 
855 	ret = bus_register(&moxtet_bus_type);
856 	if (ret < 0) {
857 		pr_err("moxtet bus registration failed: %d\n", ret);
858 		goto error;
859 	}
860 
861 	ret = spi_register_driver(&moxtet_spi_driver);
862 	if (ret < 0) {
863 		pr_err("moxtet spi driver registration failed: %d\n", ret);
864 		goto error_bus;
865 	}
866 
867 	return 0;
868 
869 error_bus:
870 	bus_unregister(&moxtet_bus_type);
871 error:
872 	return ret;
873 }
874 postcore_initcall_sync(moxtet_init);
875 
876 static void __exit moxtet_exit(void)
877 {
878 	spi_unregister_driver(&moxtet_spi_driver);
879 	bus_unregister(&moxtet_bus_type);
880 }
881 module_exit(moxtet_exit);
882 
883 MODULE_AUTHOR("Marek Behun <marek.behun@nic.cz>");
884 MODULE_DESCRIPTION("CZ.NIC's Turris Mox module configuration bus");
885 MODULE_LICENSE("GPL v2");
886