xref: /openbmc/linux/drivers/vlynq/vlynq.c (revision 3213486f)
1 /*
2  * Copyright (C) 2006, 2007 Eugene Konev <ejka@openwrt.org>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  *
18  * Parts of the VLYNQ specification can be found here:
19  * http://www.ti.com/litv/pdf/sprue36a
20  */
21 
22 #include <linux/init.h>
23 #include <linux/types.h>
24 #include <linux/kernel.h>
25 #include <linux/string.h>
26 #include <linux/device.h>
27 #include <linux/module.h>
28 #include <linux/errno.h>
29 #include <linux/platform_device.h>
30 #include <linux/interrupt.h>
31 #include <linux/delay.h>
32 #include <linux/io.h>
33 #include <linux/slab.h>
34 #include <linux/irq.h>
35 
36 #include <linux/vlynq.h>
37 
38 #define VLYNQ_CTRL_PM_ENABLE		0x80000000
39 #define VLYNQ_CTRL_CLOCK_INT		0x00008000
40 #define VLYNQ_CTRL_CLOCK_DIV(x)		(((x) & 7) << 16)
41 #define VLYNQ_CTRL_INT_LOCAL		0x00004000
42 #define VLYNQ_CTRL_INT_ENABLE		0x00002000
43 #define VLYNQ_CTRL_INT_VECTOR(x)	(((x) & 0x1f) << 8)
44 #define VLYNQ_CTRL_INT2CFG		0x00000080
45 #define VLYNQ_CTRL_RESET		0x00000001
46 
47 #define VLYNQ_CTRL_CLOCK_MASK          (0x7 << 16)
48 
49 #define VLYNQ_INT_OFFSET		0x00000014
50 #define VLYNQ_REMOTE_OFFSET		0x00000080
51 
52 #define VLYNQ_STATUS_LINK		0x00000001
53 #define VLYNQ_STATUS_LERROR		0x00000080
54 #define VLYNQ_STATUS_RERROR		0x00000100
55 
56 #define VINT_ENABLE			0x00000100
57 #define VINT_TYPE_EDGE			0x00000080
58 #define VINT_LEVEL_LOW			0x00000040
59 #define VINT_VECTOR(x)			((x) & 0x1f)
60 #define VINT_OFFSET(irq)		(8 * ((irq) % 4))
61 
62 #define VLYNQ_AUTONEGO_V2		0x00010000
63 
64 struct vlynq_regs {
65 	u32 revision;
66 	u32 control;
67 	u32 status;
68 	u32 int_prio;
69 	u32 int_status;
70 	u32 int_pending;
71 	u32 int_ptr;
72 	u32 tx_offset;
73 	struct vlynq_mapping rx_mapping[4];
74 	u32 chip;
75 	u32 autonego;
76 	u32 unused[6];
77 	u32 int_device[8];
78 };
79 
80 #ifdef CONFIG_VLYNQ_DEBUG
81 static void vlynq_dump_regs(struct vlynq_device *dev)
82 {
83 	int i;
84 
85 	printk(KERN_DEBUG "VLYNQ local=%p remote=%p\n",
86 			dev->local, dev->remote);
87 	for (i = 0; i < 32; i++) {
88 		printk(KERN_DEBUG "VLYNQ: local %d: %08x\n",
89 			i + 1, ((u32 *)dev->local)[i]);
90 		printk(KERN_DEBUG "VLYNQ: remote %d: %08x\n",
91 			i + 1, ((u32 *)dev->remote)[i]);
92 	}
93 }
94 
95 static void vlynq_dump_mem(u32 *base, int count)
96 {
97 	int i;
98 
99 	for (i = 0; i < (count + 3) / 4; i++) {
100 		if (i % 4 == 0)
101 			printk(KERN_DEBUG "\nMEM[0x%04x]:", i * 4);
102 		printk(KERN_DEBUG " 0x%08x", *(base + i));
103 	}
104 	printk(KERN_DEBUG "\n");
105 }
106 #endif
107 
108 /* Check the VLYNQ link status with a given device */
109 static int vlynq_linked(struct vlynq_device *dev)
110 {
111 	int i;
112 
113 	for (i = 0; i < 100; i++)
114 		if (readl(&dev->local->status) & VLYNQ_STATUS_LINK)
115 			return 1;
116 		else
117 			cpu_relax();
118 
119 	return 0;
120 }
121 
122 static void vlynq_reset(struct vlynq_device *dev)
123 {
124 	writel(readl(&dev->local->control) | VLYNQ_CTRL_RESET,
125 			&dev->local->control);
126 
127 	/* Wait for the devices to finish resetting */
128 	msleep(5);
129 
130 	/* Remove reset bit */
131 	writel(readl(&dev->local->control) & ~VLYNQ_CTRL_RESET,
132 			&dev->local->control);
133 
134 	/* Give some time for the devices to settle */
135 	msleep(5);
136 }
137 
138 static void vlynq_irq_unmask(struct irq_data *d)
139 {
140 	struct vlynq_device *dev = irq_data_get_irq_chip_data(d);
141 	int virq;
142 	u32 val;
143 
144 	BUG_ON(!dev);
145 	virq = d->irq - dev->irq_start;
146 	val = readl(&dev->remote->int_device[virq >> 2]);
147 	val |= (VINT_ENABLE | virq) << VINT_OFFSET(virq);
148 	writel(val, &dev->remote->int_device[virq >> 2]);
149 }
150 
151 static void vlynq_irq_mask(struct irq_data *d)
152 {
153 	struct vlynq_device *dev = irq_data_get_irq_chip_data(d);
154 	int virq;
155 	u32 val;
156 
157 	BUG_ON(!dev);
158 	virq = d->irq - dev->irq_start;
159 	val = readl(&dev->remote->int_device[virq >> 2]);
160 	val &= ~(VINT_ENABLE << VINT_OFFSET(virq));
161 	writel(val, &dev->remote->int_device[virq >> 2]);
162 }
163 
164 static int vlynq_irq_type(struct irq_data *d, unsigned int flow_type)
165 {
166 	struct vlynq_device *dev = irq_data_get_irq_chip_data(d);
167 	int virq;
168 	u32 val;
169 
170 	BUG_ON(!dev);
171 	virq = d->irq - dev->irq_start;
172 	val = readl(&dev->remote->int_device[virq >> 2]);
173 	switch (flow_type & IRQ_TYPE_SENSE_MASK) {
174 	case IRQ_TYPE_EDGE_RISING:
175 	case IRQ_TYPE_EDGE_FALLING:
176 	case IRQ_TYPE_EDGE_BOTH:
177 		val |= VINT_TYPE_EDGE << VINT_OFFSET(virq);
178 		val &= ~(VINT_LEVEL_LOW << VINT_OFFSET(virq));
179 		break;
180 	case IRQ_TYPE_LEVEL_HIGH:
181 		val &= ~(VINT_TYPE_EDGE << VINT_OFFSET(virq));
182 		val &= ~(VINT_LEVEL_LOW << VINT_OFFSET(virq));
183 		break;
184 	case IRQ_TYPE_LEVEL_LOW:
185 		val &= ~(VINT_TYPE_EDGE << VINT_OFFSET(virq));
186 		val |= VINT_LEVEL_LOW << VINT_OFFSET(virq);
187 		break;
188 	default:
189 		return -EINVAL;
190 	}
191 	writel(val, &dev->remote->int_device[virq >> 2]);
192 	return 0;
193 }
194 
195 static void vlynq_local_ack(struct irq_data *d)
196 {
197 	struct vlynq_device *dev = irq_data_get_irq_chip_data(d);
198 	u32 status = readl(&dev->local->status);
199 
200 	pr_debug("%s: local status: 0x%08x\n",
201 		       dev_name(&dev->dev), status);
202 	writel(status, &dev->local->status);
203 }
204 
205 static void vlynq_remote_ack(struct irq_data *d)
206 {
207 	struct vlynq_device *dev = irq_data_get_irq_chip_data(d);
208 	u32 status = readl(&dev->remote->status);
209 
210 	pr_debug("%s: remote status: 0x%08x\n",
211 		       dev_name(&dev->dev), status);
212 	writel(status, &dev->remote->status);
213 }
214 
215 static irqreturn_t vlynq_irq(int irq, void *dev_id)
216 {
217 	struct vlynq_device *dev = dev_id;
218 	u32 status;
219 	int virq = 0;
220 
221 	status = readl(&dev->local->int_status);
222 	writel(status, &dev->local->int_status);
223 
224 	if (unlikely(!status))
225 		spurious_interrupt();
226 
227 	while (status) {
228 		if (status & 1)
229 			do_IRQ(dev->irq_start + virq);
230 		status >>= 1;
231 		virq++;
232 	}
233 
234 	return IRQ_HANDLED;
235 }
236 
237 static struct irq_chip vlynq_irq_chip = {
238 	.name = "vlynq",
239 	.irq_unmask = vlynq_irq_unmask,
240 	.irq_mask = vlynq_irq_mask,
241 	.irq_set_type = vlynq_irq_type,
242 };
243 
244 static struct irq_chip vlynq_local_chip = {
245 	.name = "vlynq local error",
246 	.irq_unmask = vlynq_irq_unmask,
247 	.irq_mask = vlynq_irq_mask,
248 	.irq_ack = vlynq_local_ack,
249 };
250 
251 static struct irq_chip vlynq_remote_chip = {
252 	.name = "vlynq local error",
253 	.irq_unmask = vlynq_irq_unmask,
254 	.irq_mask = vlynq_irq_mask,
255 	.irq_ack = vlynq_remote_ack,
256 };
257 
258 static int vlynq_setup_irq(struct vlynq_device *dev)
259 {
260 	u32 val;
261 	int i, virq;
262 
263 	if (dev->local_irq == dev->remote_irq) {
264 		printk(KERN_ERR
265 		       "%s: local vlynq irq should be different from remote\n",
266 		       dev_name(&dev->dev));
267 		return -EINVAL;
268 	}
269 
270 	/* Clear local and remote error bits */
271 	writel(readl(&dev->local->status), &dev->local->status);
272 	writel(readl(&dev->remote->status), &dev->remote->status);
273 
274 	/* Now setup interrupts */
275 	val = VLYNQ_CTRL_INT_VECTOR(dev->local_irq);
276 	val |= VLYNQ_CTRL_INT_ENABLE | VLYNQ_CTRL_INT_LOCAL |
277 		VLYNQ_CTRL_INT2CFG;
278 	val |= readl(&dev->local->control);
279 	writel(VLYNQ_INT_OFFSET, &dev->local->int_ptr);
280 	writel(val, &dev->local->control);
281 
282 	val = VLYNQ_CTRL_INT_VECTOR(dev->remote_irq);
283 	val |= VLYNQ_CTRL_INT_ENABLE;
284 	val |= readl(&dev->remote->control);
285 	writel(VLYNQ_INT_OFFSET, &dev->remote->int_ptr);
286 	writel(val, &dev->remote->int_ptr);
287 	writel(val, &dev->remote->control);
288 
289 	for (i = dev->irq_start; i <= dev->irq_end; i++) {
290 		virq = i - dev->irq_start;
291 		if (virq == dev->local_irq) {
292 			irq_set_chip_and_handler(i, &vlynq_local_chip,
293 						 handle_level_irq);
294 			irq_set_chip_data(i, dev);
295 		} else if (virq == dev->remote_irq) {
296 			irq_set_chip_and_handler(i, &vlynq_remote_chip,
297 						 handle_level_irq);
298 			irq_set_chip_data(i, dev);
299 		} else {
300 			irq_set_chip_and_handler(i, &vlynq_irq_chip,
301 						 handle_simple_irq);
302 			irq_set_chip_data(i, dev);
303 			writel(0, &dev->remote->int_device[virq >> 2]);
304 		}
305 	}
306 
307 	if (request_irq(dev->irq, vlynq_irq, IRQF_SHARED, "vlynq", dev)) {
308 		printk(KERN_ERR "%s: request_irq failed\n",
309 					dev_name(&dev->dev));
310 		return -EAGAIN;
311 	}
312 
313 	return 0;
314 }
315 
316 static void vlynq_device_release(struct device *dev)
317 {
318 	struct vlynq_device *vdev = to_vlynq_device(dev);
319 	kfree(vdev);
320 }
321 
322 static int vlynq_device_match(struct device *dev,
323 			      struct device_driver *drv)
324 {
325 	struct vlynq_device *vdev = to_vlynq_device(dev);
326 	struct vlynq_driver *vdrv = to_vlynq_driver(drv);
327 	struct vlynq_device_id *ids = vdrv->id_table;
328 
329 	while (ids->id) {
330 		if (ids->id == vdev->dev_id) {
331 			vdev->divisor = ids->divisor;
332 			vlynq_set_drvdata(vdev, ids);
333 			printk(KERN_INFO "Driver found for VLYNQ "
334 				"device: %08x\n", vdev->dev_id);
335 			return 1;
336 		}
337 		printk(KERN_DEBUG "Not using the %08x VLYNQ device's driver"
338 			" for VLYNQ device: %08x\n", ids->id, vdev->dev_id);
339 		ids++;
340 	}
341 	return 0;
342 }
343 
344 static int vlynq_device_probe(struct device *dev)
345 {
346 	struct vlynq_device *vdev = to_vlynq_device(dev);
347 	struct vlynq_driver *drv = to_vlynq_driver(dev->driver);
348 	struct vlynq_device_id *id = vlynq_get_drvdata(vdev);
349 	int result = -ENODEV;
350 
351 	if (drv->probe)
352 		result = drv->probe(vdev, id);
353 	if (result)
354 		put_device(dev);
355 	return result;
356 }
357 
358 static int vlynq_device_remove(struct device *dev)
359 {
360 	struct vlynq_driver *drv = to_vlynq_driver(dev->driver);
361 
362 	if (drv->remove)
363 		drv->remove(to_vlynq_device(dev));
364 
365 	return 0;
366 }
367 
368 int __vlynq_register_driver(struct vlynq_driver *driver, struct module *owner)
369 {
370 	driver->driver.name = driver->name;
371 	driver->driver.bus = &vlynq_bus_type;
372 	return driver_register(&driver->driver);
373 }
374 EXPORT_SYMBOL(__vlynq_register_driver);
375 
376 void vlynq_unregister_driver(struct vlynq_driver *driver)
377 {
378 	driver_unregister(&driver->driver);
379 }
380 EXPORT_SYMBOL(vlynq_unregister_driver);
381 
382 /*
383  * A VLYNQ remote device can clock the VLYNQ bus master
384  * using a dedicated clock line. In that case, both the
385  * remove device and the bus master should have the same
386  * serial clock dividers configured. Iterate through the
387  * 8 possible dividers until we actually link with the
388  * device.
389  */
390 static int __vlynq_try_remote(struct vlynq_device *dev)
391 {
392 	int i;
393 
394 	vlynq_reset(dev);
395 	for (i = dev->dev_id ? vlynq_rdiv2 : vlynq_rdiv8; dev->dev_id ?
396 			i <= vlynq_rdiv8 : i >= vlynq_rdiv2;
397 		dev->dev_id ? i++ : i--) {
398 
399 		if (!vlynq_linked(dev))
400 			break;
401 
402 		writel((readl(&dev->remote->control) &
403 				~VLYNQ_CTRL_CLOCK_MASK) |
404 				VLYNQ_CTRL_CLOCK_INT |
405 				VLYNQ_CTRL_CLOCK_DIV(i - vlynq_rdiv1),
406 				&dev->remote->control);
407 		writel((readl(&dev->local->control)
408 				& ~(VLYNQ_CTRL_CLOCK_INT |
409 				VLYNQ_CTRL_CLOCK_MASK)) |
410 				VLYNQ_CTRL_CLOCK_DIV(i - vlynq_rdiv1),
411 				&dev->local->control);
412 
413 		if (vlynq_linked(dev)) {
414 			printk(KERN_DEBUG
415 				"%s: using remote clock divisor %d\n",
416 				dev_name(&dev->dev), i - vlynq_rdiv1 + 1);
417 			dev->divisor = i;
418 			return 0;
419 		} else {
420 			vlynq_reset(dev);
421 		}
422 	}
423 
424 	return -ENODEV;
425 }
426 
427 /*
428  * A VLYNQ remote device can be clocked by the VLYNQ bus
429  * master using a dedicated clock line. In that case, only
430  * the bus master configures the serial clock divider.
431  * Iterate through the 8 possible dividers until we
432  * actually get a link with the device.
433  */
434 static int __vlynq_try_local(struct vlynq_device *dev)
435 {
436 	int i;
437 
438 	vlynq_reset(dev);
439 
440 	for (i = dev->dev_id ? vlynq_ldiv2 : vlynq_ldiv8; dev->dev_id ?
441 			i <= vlynq_ldiv8 : i >= vlynq_ldiv2;
442 		dev->dev_id ? i++ : i--) {
443 
444 		writel((readl(&dev->local->control) &
445 				~VLYNQ_CTRL_CLOCK_MASK) |
446 				VLYNQ_CTRL_CLOCK_INT |
447 				VLYNQ_CTRL_CLOCK_DIV(i - vlynq_ldiv1),
448 				&dev->local->control);
449 
450 		if (vlynq_linked(dev)) {
451 			printk(KERN_DEBUG
452 				"%s: using local clock divisor %d\n",
453 				dev_name(&dev->dev), i - vlynq_ldiv1 + 1);
454 			dev->divisor = i;
455 			return 0;
456 		} else {
457 			vlynq_reset(dev);
458 		}
459 	}
460 
461 	return -ENODEV;
462 }
463 
464 /*
465  * When using external clocking method, serial clock
466  * is supplied by an external oscillator, therefore we
467  * should mask the local clock bit in the clock control
468  * register for both the bus master and the remote device.
469  */
470 static int __vlynq_try_external(struct vlynq_device *dev)
471 {
472 	vlynq_reset(dev);
473 	if (!vlynq_linked(dev))
474 		return -ENODEV;
475 
476 	writel((readl(&dev->remote->control) &
477 			~VLYNQ_CTRL_CLOCK_INT),
478 			&dev->remote->control);
479 
480 	writel((readl(&dev->local->control) &
481 			~VLYNQ_CTRL_CLOCK_INT),
482 			&dev->local->control);
483 
484 	if (vlynq_linked(dev)) {
485 		printk(KERN_DEBUG "%s: using external clock\n",
486 			dev_name(&dev->dev));
487 			dev->divisor = vlynq_div_external;
488 		return 0;
489 	}
490 
491 	return -ENODEV;
492 }
493 
494 static int __vlynq_enable_device(struct vlynq_device *dev)
495 {
496 	int result;
497 	struct plat_vlynq_ops *ops = dev->dev.platform_data;
498 
499 	result = ops->on(dev);
500 	if (result)
501 		return result;
502 
503 	switch (dev->divisor) {
504 	case vlynq_div_external:
505 	case vlynq_div_auto:
506 		/* When the device is brought from reset it should have clock
507 		 * generation negotiated by hardware.
508 		 * Check which device is generating clocks and perform setup
509 		 * accordingly */
510 		if (vlynq_linked(dev) && readl(&dev->remote->control) &
511 		   VLYNQ_CTRL_CLOCK_INT) {
512 			if (!__vlynq_try_remote(dev) ||
513 				!__vlynq_try_local(dev)  ||
514 				!__vlynq_try_external(dev))
515 				return 0;
516 		} else {
517 			if (!__vlynq_try_external(dev) ||
518 				!__vlynq_try_local(dev)    ||
519 				!__vlynq_try_remote(dev))
520 				return 0;
521 		}
522 		break;
523 	case vlynq_ldiv1:
524 	case vlynq_ldiv2:
525 	case vlynq_ldiv3:
526 	case vlynq_ldiv4:
527 	case vlynq_ldiv5:
528 	case vlynq_ldiv6:
529 	case vlynq_ldiv7:
530 	case vlynq_ldiv8:
531 		writel(VLYNQ_CTRL_CLOCK_INT |
532 			VLYNQ_CTRL_CLOCK_DIV(dev->divisor -
533 			vlynq_ldiv1), &dev->local->control);
534 		writel(0, &dev->remote->control);
535 		if (vlynq_linked(dev)) {
536 			printk(KERN_DEBUG
537 				"%s: using local clock divisor %d\n",
538 				dev_name(&dev->dev),
539 				dev->divisor - vlynq_ldiv1 + 1);
540 			return 0;
541 		}
542 		break;
543 	case vlynq_rdiv1:
544 	case vlynq_rdiv2:
545 	case vlynq_rdiv3:
546 	case vlynq_rdiv4:
547 	case vlynq_rdiv5:
548 	case vlynq_rdiv6:
549 	case vlynq_rdiv7:
550 	case vlynq_rdiv8:
551 		writel(0, &dev->local->control);
552 		writel(VLYNQ_CTRL_CLOCK_INT |
553 			VLYNQ_CTRL_CLOCK_DIV(dev->divisor -
554 			vlynq_rdiv1), &dev->remote->control);
555 		if (vlynq_linked(dev)) {
556 			printk(KERN_DEBUG
557 				"%s: using remote clock divisor %d\n",
558 				dev_name(&dev->dev),
559 				dev->divisor - vlynq_rdiv1 + 1);
560 			return 0;
561 		}
562 		break;
563 	}
564 
565 	ops->off(dev);
566 	return -ENODEV;
567 }
568 
569 int vlynq_enable_device(struct vlynq_device *dev)
570 {
571 	struct plat_vlynq_ops *ops = dev->dev.platform_data;
572 	int result = -ENODEV;
573 
574 	result = __vlynq_enable_device(dev);
575 	if (result)
576 		return result;
577 
578 	result = vlynq_setup_irq(dev);
579 	if (result)
580 		ops->off(dev);
581 
582 	dev->enabled = !result;
583 	return result;
584 }
585 EXPORT_SYMBOL(vlynq_enable_device);
586 
587 
588 void vlynq_disable_device(struct vlynq_device *dev)
589 {
590 	struct plat_vlynq_ops *ops = dev->dev.platform_data;
591 
592 	dev->enabled = 0;
593 	free_irq(dev->irq, dev);
594 	ops->off(dev);
595 }
596 EXPORT_SYMBOL(vlynq_disable_device);
597 
598 int vlynq_set_local_mapping(struct vlynq_device *dev, u32 tx_offset,
599 			    struct vlynq_mapping *mapping)
600 {
601 	int i;
602 
603 	if (!dev->enabled)
604 		return -ENXIO;
605 
606 	writel(tx_offset, &dev->local->tx_offset);
607 	for (i = 0; i < 4; i++) {
608 		writel(mapping[i].offset, &dev->local->rx_mapping[i].offset);
609 		writel(mapping[i].size, &dev->local->rx_mapping[i].size);
610 	}
611 	return 0;
612 }
613 EXPORT_SYMBOL(vlynq_set_local_mapping);
614 
615 int vlynq_set_remote_mapping(struct vlynq_device *dev, u32 tx_offset,
616 			     struct vlynq_mapping *mapping)
617 {
618 	int i;
619 
620 	if (!dev->enabled)
621 		return -ENXIO;
622 
623 	writel(tx_offset, &dev->remote->tx_offset);
624 	for (i = 0; i < 4; i++) {
625 		writel(mapping[i].offset, &dev->remote->rx_mapping[i].offset);
626 		writel(mapping[i].size, &dev->remote->rx_mapping[i].size);
627 	}
628 	return 0;
629 }
630 EXPORT_SYMBOL(vlynq_set_remote_mapping);
631 
632 int vlynq_set_local_irq(struct vlynq_device *dev, int virq)
633 {
634 	int irq = dev->irq_start + virq;
635 	if (dev->enabled)
636 		return -EBUSY;
637 
638 	if ((irq < dev->irq_start) || (irq > dev->irq_end))
639 		return -EINVAL;
640 
641 	if (virq == dev->remote_irq)
642 		return -EINVAL;
643 
644 	dev->local_irq = virq;
645 
646 	return 0;
647 }
648 EXPORT_SYMBOL(vlynq_set_local_irq);
649 
650 int vlynq_set_remote_irq(struct vlynq_device *dev, int virq)
651 {
652 	int irq = dev->irq_start + virq;
653 	if (dev->enabled)
654 		return -EBUSY;
655 
656 	if ((irq < dev->irq_start) || (irq > dev->irq_end))
657 		return -EINVAL;
658 
659 	if (virq == dev->local_irq)
660 		return -EINVAL;
661 
662 	dev->remote_irq = virq;
663 
664 	return 0;
665 }
666 EXPORT_SYMBOL(vlynq_set_remote_irq);
667 
668 static int vlynq_probe(struct platform_device *pdev)
669 {
670 	struct vlynq_device *dev;
671 	struct resource *regs_res, *mem_res, *irq_res;
672 	int len, result;
673 
674 	regs_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
675 	if (!regs_res)
676 		return -ENODEV;
677 
678 	mem_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem");
679 	if (!mem_res)
680 		return -ENODEV;
681 
682 	irq_res = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "devirq");
683 	if (!irq_res)
684 		return -ENODEV;
685 
686 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
687 	if (!dev) {
688 		printk(KERN_ERR
689 		       "vlynq: failed to allocate device structure\n");
690 		return -ENOMEM;
691 	}
692 
693 	dev->id = pdev->id;
694 	dev->dev.bus = &vlynq_bus_type;
695 	dev->dev.parent = &pdev->dev;
696 	dev_set_name(&dev->dev, "vlynq%d", dev->id);
697 	dev->dev.platform_data = pdev->dev.platform_data;
698 	dev->dev.release = vlynq_device_release;
699 
700 	dev->regs_start = regs_res->start;
701 	dev->regs_end = regs_res->end;
702 	dev->mem_start = mem_res->start;
703 	dev->mem_end = mem_res->end;
704 
705 	len = resource_size(regs_res);
706 	if (!request_mem_region(regs_res->start, len, dev_name(&dev->dev))) {
707 		printk(KERN_ERR "%s: Can't request vlynq registers\n",
708 		       dev_name(&dev->dev));
709 		result = -ENXIO;
710 		goto fail_request;
711 	}
712 
713 	dev->local = ioremap(regs_res->start, len);
714 	if (!dev->local) {
715 		printk(KERN_ERR "%s: Can't remap vlynq registers\n",
716 		       dev_name(&dev->dev));
717 		result = -ENXIO;
718 		goto fail_remap;
719 	}
720 
721 	dev->remote = (struct vlynq_regs *)((void *)dev->local +
722 					    VLYNQ_REMOTE_OFFSET);
723 
724 	dev->irq = platform_get_irq_byname(pdev, "irq");
725 	dev->irq_start = irq_res->start;
726 	dev->irq_end = irq_res->end;
727 	dev->local_irq = dev->irq_end - dev->irq_start;
728 	dev->remote_irq = dev->local_irq - 1;
729 
730 	if (device_register(&dev->dev))
731 		goto fail_register;
732 	platform_set_drvdata(pdev, dev);
733 
734 	printk(KERN_INFO "%s: regs 0x%p, irq %d, mem 0x%p\n",
735 	       dev_name(&dev->dev), (void *)dev->regs_start, dev->irq,
736 	       (void *)dev->mem_start);
737 
738 	dev->dev_id = 0;
739 	dev->divisor = vlynq_div_auto;
740 	result = __vlynq_enable_device(dev);
741 	if (result == 0) {
742 		dev->dev_id = readl(&dev->remote->chip);
743 		((struct plat_vlynq_ops *)(dev->dev.platform_data))->off(dev);
744 	}
745 	if (dev->dev_id)
746 		printk(KERN_INFO "Found a VLYNQ device: %08x\n", dev->dev_id);
747 
748 	return 0;
749 
750 fail_register:
751 	iounmap(dev->local);
752 fail_remap:
753 fail_request:
754 	release_mem_region(regs_res->start, len);
755 	kfree(dev);
756 	return result;
757 }
758 
759 static int vlynq_remove(struct platform_device *pdev)
760 {
761 	struct vlynq_device *dev = platform_get_drvdata(pdev);
762 
763 	device_unregister(&dev->dev);
764 	iounmap(dev->local);
765 	release_mem_region(dev->regs_start,
766 			   dev->regs_end - dev->regs_start + 1);
767 
768 	kfree(dev);
769 
770 	return 0;
771 }
772 
773 static struct platform_driver vlynq_platform_driver = {
774 	.driver.name = "vlynq",
775 	.probe = vlynq_probe,
776 	.remove = vlynq_remove,
777 };
778 
779 struct bus_type vlynq_bus_type = {
780 	.name = "vlynq",
781 	.match = vlynq_device_match,
782 	.probe = vlynq_device_probe,
783 	.remove = vlynq_device_remove,
784 };
785 EXPORT_SYMBOL(vlynq_bus_type);
786 
787 static int vlynq_init(void)
788 {
789 	int res = 0;
790 
791 	res = bus_register(&vlynq_bus_type);
792 	if (res)
793 		goto fail_bus;
794 
795 	res = platform_driver_register(&vlynq_platform_driver);
796 	if (res)
797 		goto fail_platform;
798 
799 	return 0;
800 
801 fail_platform:
802 	bus_unregister(&vlynq_bus_type);
803 fail_bus:
804 	return res;
805 }
806 
807 static void vlynq_exit(void)
808 {
809 	platform_driver_unregister(&vlynq_platform_driver);
810 	bus_unregister(&vlynq_bus_type);
811 }
812 
813 module_init(vlynq_init);
814 module_exit(vlynq_exit);
815