xref: /openbmc/linux/drivers/mfd/ucb1x00-core.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  *  linux/drivers/mfd/ucb1x00-core.c
3  *
4  *  Copyright (C) 2001 Russell King, All Rights Reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License.
9  *
10  *  The UCB1x00 core driver provides basic services for handling IO,
11  *  the ADC, interrupts, and accessing registers.  It is designed
12  *  such that everything goes through this layer, thereby providing
13  *  a consistent locking methodology, as well as allowing the drivers
14  *  to be used on other non-MCP-enabled hardware platforms.
15  *
16  *  Note that all locks are private to this file.  Nothing else may
17  *  touch them.
18  */
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/init.h>
24 #include <linux/errno.h>
25 #include <linux/interrupt.h>
26 #include <linux/device.h>
27 #include <linux/mutex.h>
28 #include <linux/mfd/ucb1x00.h>
29 #include <linux/gpio.h>
30 #include <linux/semaphore.h>
31 
32 #include <mach/dma.h>
33 #include <mach/hardware.h>
34 
35 static DEFINE_MUTEX(ucb1x00_mutex);
36 static LIST_HEAD(ucb1x00_drivers);
37 static LIST_HEAD(ucb1x00_devices);
38 
39 /**
40  *	ucb1x00_io_set_dir - set IO direction
41  *	@ucb: UCB1x00 structure describing chip
42  *	@in:  bitfield of IO pins to be set as inputs
43  *	@out: bitfield of IO pins to be set as outputs
44  *
45  *	Set the IO direction of the ten general purpose IO pins on
46  *	the UCB1x00 chip.  The @in bitfield has priority over the
47  *	@out bitfield, in that if you specify a pin as both input
48  *	and output, it will end up as an input.
49  *
50  *	ucb1x00_enable must have been called to enable the comms
51  *	before using this function.
52  *
53  *	This function takes a spinlock, disabling interrupts.
54  */
55 void ucb1x00_io_set_dir(struct ucb1x00 *ucb, unsigned int in, unsigned int out)
56 {
57 	unsigned long flags;
58 
59 	spin_lock_irqsave(&ucb->io_lock, flags);
60 	ucb->io_dir |= out;
61 	ucb->io_dir &= ~in;
62 
63 	ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
64 	spin_unlock_irqrestore(&ucb->io_lock, flags);
65 }
66 
67 /**
68  *	ucb1x00_io_write - set or clear IO outputs
69  *	@ucb:   UCB1x00 structure describing chip
70  *	@set:   bitfield of IO pins to set to logic '1'
71  *	@clear: bitfield of IO pins to set to logic '0'
72  *
73  *	Set the IO output state of the specified IO pins.  The value
74  *	is retained if the pins are subsequently configured as inputs.
75  *	The @clear bitfield has priority over the @set bitfield -
76  *	outputs will be cleared.
77  *
78  *	ucb1x00_enable must have been called to enable the comms
79  *	before using this function.
80  *
81  *	This function takes a spinlock, disabling interrupts.
82  */
83 void ucb1x00_io_write(struct ucb1x00 *ucb, unsigned int set, unsigned int clear)
84 {
85 	unsigned long flags;
86 
87 	spin_lock_irqsave(&ucb->io_lock, flags);
88 	ucb->io_out |= set;
89 	ucb->io_out &= ~clear;
90 
91 	ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out);
92 	spin_unlock_irqrestore(&ucb->io_lock, flags);
93 }
94 
95 /**
96  *	ucb1x00_io_read - read the current state of the IO pins
97  *	@ucb: UCB1x00 structure describing chip
98  *
99  *	Return a bitfield describing the logic state of the ten
100  *	general purpose IO pins.
101  *
102  *	ucb1x00_enable must have been called to enable the comms
103  *	before using this function.
104  *
105  *	This function does not take any semaphores or spinlocks.
106  */
107 unsigned int ucb1x00_io_read(struct ucb1x00 *ucb)
108 {
109 	return ucb1x00_reg_read(ucb, UCB_IO_DATA);
110 }
111 
112 static void ucb1x00_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
113 {
114 	struct ucb1x00 *ucb = container_of(chip, struct ucb1x00, gpio);
115 	unsigned long flags;
116 
117 	spin_lock_irqsave(&ucb->io_lock, flags);
118 	if (value)
119 		ucb->io_out |= 1 << offset;
120 	else
121 		ucb->io_out &= ~(1 << offset);
122 
123 	ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out);
124 	spin_unlock_irqrestore(&ucb->io_lock, flags);
125 }
126 
127 static int ucb1x00_gpio_get(struct gpio_chip *chip, unsigned offset)
128 {
129 	struct ucb1x00 *ucb = container_of(chip, struct ucb1x00, gpio);
130 	return ucb1x00_reg_read(ucb, UCB_IO_DATA) & (1 << offset);
131 }
132 
133 static int ucb1x00_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
134 {
135 	struct ucb1x00 *ucb = container_of(chip, struct ucb1x00, gpio);
136 	unsigned long flags;
137 
138 	spin_lock_irqsave(&ucb->io_lock, flags);
139 	ucb->io_dir &= ~(1 << offset);
140 	ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
141 	spin_unlock_irqrestore(&ucb->io_lock, flags);
142 
143 	return 0;
144 }
145 
146 static int ucb1x00_gpio_direction_output(struct gpio_chip *chip, unsigned offset
147 		, int value)
148 {
149 	struct ucb1x00 *ucb = container_of(chip, struct ucb1x00, gpio);
150 	unsigned long flags;
151 
152 	spin_lock_irqsave(&ucb->io_lock, flags);
153 	ucb->io_dir |= (1 << offset);
154 	ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
155 
156 	if (value)
157 		ucb->io_out |= 1 << offset;
158 	else
159 		ucb->io_out &= ~(1 << offset);
160 	ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out);
161 	spin_unlock_irqrestore(&ucb->io_lock, flags);
162 
163 	return 0;
164 }
165 
166 /*
167  * UCB1300 data sheet says we must:
168  *  1. enable ADC	=> 5us (including reference startup time)
169  *  2. select input	=> 51*tsibclk  => 4.3us
170  *  3. start conversion	=> 102*tsibclk => 8.5us
171  * (tsibclk = 1/11981000)
172  * Period between SIB 128-bit frames = 10.7us
173  */
174 
175 /**
176  *	ucb1x00_adc_enable - enable the ADC converter
177  *	@ucb: UCB1x00 structure describing chip
178  *
179  *	Enable the ucb1x00 and ADC converter on the UCB1x00 for use.
180  *	Any code wishing to use the ADC converter must call this
181  *	function prior to using it.
182  *
183  *	This function takes the ADC semaphore to prevent two or more
184  *	concurrent uses, and therefore may sleep.  As a result, it
185  *	can only be called from process context, not interrupt
186  *	context.
187  *
188  *	You should release the ADC as soon as possible using
189  *	ucb1x00_adc_disable.
190  */
191 void ucb1x00_adc_enable(struct ucb1x00 *ucb)
192 {
193 	down(&ucb->adc_sem);
194 
195 	ucb->adc_cr |= UCB_ADC_ENA;
196 
197 	ucb1x00_enable(ucb);
198 	ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr);
199 }
200 
201 /**
202  *	ucb1x00_adc_read - read the specified ADC channel
203  *	@ucb: UCB1x00 structure describing chip
204  *	@adc_channel: ADC channel mask
205  *	@sync: wait for syncronisation pulse.
206  *
207  *	Start an ADC conversion and wait for the result.  Note that
208  *	synchronised ADC conversions (via the ADCSYNC pin) must wait
209  *	until the trigger is asserted and the conversion is finished.
210  *
211  *	This function currently spins waiting for the conversion to
212  *	complete (2 frames max without sync).
213  *
214  *	If called for a synchronised ADC conversion, it may sleep
215  *	with the ADC semaphore held.
216  */
217 unsigned int ucb1x00_adc_read(struct ucb1x00 *ucb, int adc_channel, int sync)
218 {
219 	unsigned int val;
220 
221 	if (sync)
222 		adc_channel |= UCB_ADC_SYNC_ENA;
223 
224 	ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr | adc_channel);
225 	ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr | adc_channel | UCB_ADC_START);
226 
227 	for (;;) {
228 		val = ucb1x00_reg_read(ucb, UCB_ADC_DATA);
229 		if (val & UCB_ADC_DAT_VAL)
230 			break;
231 		/* yield to other processes */
232 		set_current_state(TASK_INTERRUPTIBLE);
233 		schedule_timeout(1);
234 	}
235 
236 	return UCB_ADC_DAT(val);
237 }
238 
239 /**
240  *	ucb1x00_adc_disable - disable the ADC converter
241  *	@ucb: UCB1x00 structure describing chip
242  *
243  *	Disable the ADC converter and release the ADC semaphore.
244  */
245 void ucb1x00_adc_disable(struct ucb1x00 *ucb)
246 {
247 	ucb->adc_cr &= ~UCB_ADC_ENA;
248 	ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr);
249 	ucb1x00_disable(ucb);
250 
251 	up(&ucb->adc_sem);
252 }
253 
254 /*
255  * UCB1x00 Interrupt handling.
256  *
257  * The UCB1x00 can generate interrupts when the SIBCLK is stopped.
258  * Since we need to read an internal register, we must re-enable
259  * SIBCLK to talk to the chip.  We leave the clock running until
260  * we have finished processing all interrupts from the chip.
261  */
262 static irqreturn_t ucb1x00_irq(int irqnr, void *devid)
263 {
264 	struct ucb1x00 *ucb = devid;
265 	struct ucb1x00_irq *irq;
266 	unsigned int isr, i;
267 
268 	ucb1x00_enable(ucb);
269 	isr = ucb1x00_reg_read(ucb, UCB_IE_STATUS);
270 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, isr);
271 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0);
272 
273 	for (i = 0, irq = ucb->irq_handler; i < 16 && isr; i++, isr >>= 1, irq++)
274 		if (isr & 1 && irq->fn)
275 			irq->fn(i, irq->devid);
276 	ucb1x00_disable(ucb);
277 
278 	return IRQ_HANDLED;
279 }
280 
281 /**
282  *	ucb1x00_hook_irq - hook a UCB1x00 interrupt
283  *	@ucb:   UCB1x00 structure describing chip
284  *	@idx:   interrupt index
285  *	@fn:    function to call when interrupt is triggered
286  *	@devid: device id to pass to interrupt handler
287  *
288  *	Hook the specified interrupt.  You can only register one handler
289  *	for each interrupt source.  The interrupt source is not enabled
290  *	by this function; use ucb1x00_enable_irq instead.
291  *
292  *	Interrupt handlers will be called with other interrupts enabled.
293  *
294  *	Returns zero on success, or one of the following errors:
295  *	 -EINVAL if the interrupt index is invalid
296  *	 -EBUSY if the interrupt has already been hooked
297  */
298 int ucb1x00_hook_irq(struct ucb1x00 *ucb, unsigned int idx, void (*fn)(int, void *), void *devid)
299 {
300 	struct ucb1x00_irq *irq;
301 	int ret = -EINVAL;
302 
303 	if (idx < 16) {
304 		irq = ucb->irq_handler + idx;
305 		ret = -EBUSY;
306 
307 		spin_lock_irq(&ucb->lock);
308 		if (irq->fn == NULL) {
309 			irq->devid = devid;
310 			irq->fn = fn;
311 			ret = 0;
312 		}
313 		spin_unlock_irq(&ucb->lock);
314 	}
315 	return ret;
316 }
317 
318 /**
319  *	ucb1x00_enable_irq - enable an UCB1x00 interrupt source
320  *	@ucb: UCB1x00 structure describing chip
321  *	@idx: interrupt index
322  *	@edges: interrupt edges to enable
323  *
324  *	Enable the specified interrupt to trigger on %UCB_RISING,
325  *	%UCB_FALLING or both edges.  The interrupt should have been
326  *	hooked by ucb1x00_hook_irq.
327  */
328 void ucb1x00_enable_irq(struct ucb1x00 *ucb, unsigned int idx, int edges)
329 {
330 	unsigned long flags;
331 
332 	if (idx < 16) {
333 		spin_lock_irqsave(&ucb->lock, flags);
334 
335 		ucb1x00_enable(ucb);
336 		if (edges & UCB_RISING) {
337 			ucb->irq_ris_enbl |= 1 << idx;
338 			ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl);
339 		}
340 		if (edges & UCB_FALLING) {
341 			ucb->irq_fal_enbl |= 1 << idx;
342 			ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl);
343 		}
344 		ucb1x00_disable(ucb);
345 		spin_unlock_irqrestore(&ucb->lock, flags);
346 	}
347 }
348 
349 /**
350  *	ucb1x00_disable_irq - disable an UCB1x00 interrupt source
351  *	@ucb: UCB1x00 structure describing chip
352  *	@edges: interrupt edges to disable
353  *
354  *	Disable the specified interrupt triggering on the specified
355  *	(%UCB_RISING, %UCB_FALLING or both) edges.
356  */
357 void ucb1x00_disable_irq(struct ucb1x00 *ucb, unsigned int idx, int edges)
358 {
359 	unsigned long flags;
360 
361 	if (idx < 16) {
362 		spin_lock_irqsave(&ucb->lock, flags);
363 
364 		ucb1x00_enable(ucb);
365 		if (edges & UCB_RISING) {
366 			ucb->irq_ris_enbl &= ~(1 << idx);
367 			ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl);
368 		}
369 		if (edges & UCB_FALLING) {
370 			ucb->irq_fal_enbl &= ~(1 << idx);
371 			ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl);
372 		}
373 		ucb1x00_disable(ucb);
374 		spin_unlock_irqrestore(&ucb->lock, flags);
375 	}
376 }
377 
378 /**
379  *	ucb1x00_free_irq - disable and free the specified UCB1x00 interrupt
380  *	@ucb: UCB1x00 structure describing chip
381  *	@idx: interrupt index
382  *	@devid: device id.
383  *
384  *	Disable the interrupt source and remove the handler.  devid must
385  *	match the devid passed when hooking the interrupt.
386  *
387  *	Returns zero on success, or one of the following errors:
388  *	 -EINVAL if the interrupt index is invalid
389  *	 -ENOENT if devid does not match
390  */
391 int ucb1x00_free_irq(struct ucb1x00 *ucb, unsigned int idx, void *devid)
392 {
393 	struct ucb1x00_irq *irq;
394 	int ret;
395 
396 	if (idx >= 16)
397 		goto bad;
398 
399 	irq = ucb->irq_handler + idx;
400 	ret = -ENOENT;
401 
402 	spin_lock_irq(&ucb->lock);
403 	if (irq->devid == devid) {
404 		ucb->irq_ris_enbl &= ~(1 << idx);
405 		ucb->irq_fal_enbl &= ~(1 << idx);
406 
407 		ucb1x00_enable(ucb);
408 		ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl);
409 		ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl);
410 		ucb1x00_disable(ucb);
411 
412 		irq->fn = NULL;
413 		irq->devid = NULL;
414 		ret = 0;
415 	}
416 	spin_unlock_irq(&ucb->lock);
417 	return ret;
418 
419 bad:
420 	printk(KERN_ERR "Freeing bad UCB1x00 irq %d\n", idx);
421 	return -EINVAL;
422 }
423 
424 static int ucb1x00_add_dev(struct ucb1x00 *ucb, struct ucb1x00_driver *drv)
425 {
426 	struct ucb1x00_dev *dev;
427 	int ret = -ENOMEM;
428 
429 	dev = kmalloc(sizeof(struct ucb1x00_dev), GFP_KERNEL);
430 	if (dev) {
431 		dev->ucb = ucb;
432 		dev->drv = drv;
433 
434 		ret = drv->add(dev);
435 
436 		if (ret == 0) {
437 			list_add(&dev->dev_node, &ucb->devs);
438 			list_add(&dev->drv_node, &drv->devs);
439 		} else {
440 			kfree(dev);
441 		}
442 	}
443 	return ret;
444 }
445 
446 static void ucb1x00_remove_dev(struct ucb1x00_dev *dev)
447 {
448 	dev->drv->remove(dev);
449 	list_del(&dev->dev_node);
450 	list_del(&dev->drv_node);
451 	kfree(dev);
452 }
453 
454 /*
455  * Try to probe our interrupt, rather than relying on lots of
456  * hard-coded machine dependencies.  For reference, the expected
457  * IRQ mappings are:
458  *
459  *  	Machine		Default IRQ
460  *	adsbitsy	IRQ_GPCIN4
461  *	cerf		IRQ_GPIO_UCB1200_IRQ
462  *	flexanet	IRQ_GPIO_GUI
463  *	freebird	IRQ_GPIO_FREEBIRD_UCB1300_IRQ
464  *	graphicsclient	ADS_EXT_IRQ(8)
465  *	graphicsmaster	ADS_EXT_IRQ(8)
466  *	lart		LART_IRQ_UCB1200
467  *	omnimeter	IRQ_GPIO23
468  *	pfs168		IRQ_GPIO_UCB1300_IRQ
469  *	simpad		IRQ_GPIO_UCB1300_IRQ
470  *	shannon		SHANNON_IRQ_GPIO_IRQ_CODEC
471  *	yopy		IRQ_GPIO_UCB1200_IRQ
472  */
473 static int ucb1x00_detect_irq(struct ucb1x00 *ucb)
474 {
475 	unsigned long mask;
476 
477 	mask = probe_irq_on();
478 	if (!mask) {
479 		probe_irq_off(mask);
480 		return NO_IRQ;
481 	}
482 
483 	/*
484 	 * Enable the ADC interrupt.
485 	 */
486 	ucb1x00_reg_write(ucb, UCB_IE_RIS, UCB_IE_ADC);
487 	ucb1x00_reg_write(ucb, UCB_IE_FAL, UCB_IE_ADC);
488 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
489 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0);
490 
491 	/*
492 	 * Cause an ADC interrupt.
493 	 */
494 	ucb1x00_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
495 	ucb1x00_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
496 
497 	/*
498 	 * Wait for the conversion to complete.
499 	 */
500 	while ((ucb1x00_reg_read(ucb, UCB_ADC_DATA) & UCB_ADC_DAT_VAL) == 0);
501 	ucb1x00_reg_write(ucb, UCB_ADC_CR, 0);
502 
503 	/*
504 	 * Disable and clear interrupt.
505 	 */
506 	ucb1x00_reg_write(ucb, UCB_IE_RIS, 0);
507 	ucb1x00_reg_write(ucb, UCB_IE_FAL, 0);
508 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
509 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0);
510 
511 	/*
512 	 * Read triggered interrupt.
513 	 */
514 	return probe_irq_off(mask);
515 }
516 
517 static void ucb1x00_release(struct device *dev)
518 {
519 	struct ucb1x00 *ucb = classdev_to_ucb1x00(dev);
520 	kfree(ucb);
521 }
522 
523 static struct class ucb1x00_class = {
524 	.name		= "ucb1x00",
525 	.dev_release	= ucb1x00_release,
526 };
527 
528 static int ucb1x00_probe(struct mcp *mcp)
529 {
530 	struct ucb1x00 *ucb;
531 	struct ucb1x00_driver *drv;
532 	unsigned int id;
533 	int ret = -ENODEV;
534 	int temp;
535 
536 	mcp_enable(mcp);
537 	id = mcp_reg_read(mcp, UCB_ID);
538 
539 	if (id != UCB_ID_1200 && id != UCB_ID_1300 && id != UCB_ID_TC35143) {
540 		printk(KERN_WARNING "UCB1x00 ID not found: %04x\n", id);
541 		goto err_disable;
542 	}
543 
544 	ucb = kzalloc(sizeof(struct ucb1x00), GFP_KERNEL);
545 	ret = -ENOMEM;
546 	if (!ucb)
547 		goto err_disable;
548 
549 
550 	ucb->dev.class = &ucb1x00_class;
551 	ucb->dev.parent = &mcp->attached_device;
552 	dev_set_name(&ucb->dev, "ucb1x00");
553 
554 	spin_lock_init(&ucb->lock);
555 	spin_lock_init(&ucb->io_lock);
556 	sema_init(&ucb->adc_sem, 1);
557 
558 	ucb->id  = id;
559 	ucb->mcp = mcp;
560 	ucb->irq = ucb1x00_detect_irq(ucb);
561 	if (ucb->irq == NO_IRQ) {
562 		printk(KERN_ERR "UCB1x00: IRQ probe failed\n");
563 		ret = -ENODEV;
564 		goto err_free;
565 	}
566 
567 	ucb->gpio.base = -1;
568 	if (mcp->gpio_base != 0) {
569 		ucb->gpio.label = dev_name(&ucb->dev);
570 		ucb->gpio.base = mcp->gpio_base;
571 		ucb->gpio.ngpio = 10;
572 		ucb->gpio.set = ucb1x00_gpio_set;
573 		ucb->gpio.get = ucb1x00_gpio_get;
574 		ucb->gpio.direction_input = ucb1x00_gpio_direction_input;
575 		ucb->gpio.direction_output = ucb1x00_gpio_direction_output;
576 		ret = gpiochip_add(&ucb->gpio);
577 		if (ret)
578 			goto err_free;
579 	} else
580 		dev_info(&ucb->dev, "gpio_base not set so no gpiolib support");
581 
582 	ret = request_irq(ucb->irq, ucb1x00_irq, IRQF_TRIGGER_RISING,
583 			  "UCB1x00", ucb);
584 	if (ret) {
585 		printk(KERN_ERR "ucb1x00: unable to grab irq%d: %d\n",
586 			ucb->irq, ret);
587 		goto err_gpio;
588 	}
589 
590 	mcp_set_drvdata(mcp, ucb);
591 
592 	ret = device_register(&ucb->dev);
593 	if (ret)
594 		goto err_irq;
595 
596 
597 	INIT_LIST_HEAD(&ucb->devs);
598 	mutex_lock(&ucb1x00_mutex);
599 	list_add(&ucb->node, &ucb1x00_devices);
600 	list_for_each_entry(drv, &ucb1x00_drivers, node) {
601 		ucb1x00_add_dev(ucb, drv);
602 	}
603 	mutex_unlock(&ucb1x00_mutex);
604 
605 	goto out;
606 
607  err_irq:
608 	free_irq(ucb->irq, ucb);
609  err_gpio:
610 	if (ucb->gpio.base != -1)
611 		temp = gpiochip_remove(&ucb->gpio);
612  err_free:
613 	kfree(ucb);
614  err_disable:
615 	mcp_disable(mcp);
616  out:
617 	return ret;
618 }
619 
620 static void ucb1x00_remove(struct mcp *mcp)
621 {
622 	struct ucb1x00 *ucb = mcp_get_drvdata(mcp);
623 	struct list_head *l, *n;
624 	int ret;
625 
626 	mutex_lock(&ucb1x00_mutex);
627 	list_del(&ucb->node);
628 	list_for_each_safe(l, n, &ucb->devs) {
629 		struct ucb1x00_dev *dev = list_entry(l, struct ucb1x00_dev, dev_node);
630 		ucb1x00_remove_dev(dev);
631 	}
632 	mutex_unlock(&ucb1x00_mutex);
633 
634 	if (ucb->gpio.base != -1) {
635 		ret = gpiochip_remove(&ucb->gpio);
636 		if (ret)
637 			dev_err(&ucb->dev, "Can't remove gpio chip: %d\n", ret);
638 	}
639 
640 	free_irq(ucb->irq, ucb);
641 	device_unregister(&ucb->dev);
642 }
643 
644 int ucb1x00_register_driver(struct ucb1x00_driver *drv)
645 {
646 	struct ucb1x00 *ucb;
647 
648 	INIT_LIST_HEAD(&drv->devs);
649 	mutex_lock(&ucb1x00_mutex);
650 	list_add(&drv->node, &ucb1x00_drivers);
651 	list_for_each_entry(ucb, &ucb1x00_devices, node) {
652 		ucb1x00_add_dev(ucb, drv);
653 	}
654 	mutex_unlock(&ucb1x00_mutex);
655 	return 0;
656 }
657 
658 void ucb1x00_unregister_driver(struct ucb1x00_driver *drv)
659 {
660 	struct list_head *n, *l;
661 
662 	mutex_lock(&ucb1x00_mutex);
663 	list_del(&drv->node);
664 	list_for_each_safe(l, n, &drv->devs) {
665 		struct ucb1x00_dev *dev = list_entry(l, struct ucb1x00_dev, drv_node);
666 		ucb1x00_remove_dev(dev);
667 	}
668 	mutex_unlock(&ucb1x00_mutex);
669 }
670 
671 static int ucb1x00_suspend(struct mcp *mcp, pm_message_t state)
672 {
673 	struct ucb1x00 *ucb = mcp_get_drvdata(mcp);
674 	struct ucb1x00_dev *dev;
675 
676 	mutex_lock(&ucb1x00_mutex);
677 	list_for_each_entry(dev, &ucb->devs, dev_node) {
678 		if (dev->drv->suspend)
679 			dev->drv->suspend(dev, state);
680 	}
681 	mutex_unlock(&ucb1x00_mutex);
682 	return 0;
683 }
684 
685 static int ucb1x00_resume(struct mcp *mcp)
686 {
687 	struct ucb1x00 *ucb = mcp_get_drvdata(mcp);
688 	struct ucb1x00_dev *dev;
689 
690 	ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
691 	mutex_lock(&ucb1x00_mutex);
692 	list_for_each_entry(dev, &ucb->devs, dev_node) {
693 		if (dev->drv->resume)
694 			dev->drv->resume(dev);
695 	}
696 	mutex_unlock(&ucb1x00_mutex);
697 	return 0;
698 }
699 
700 static struct mcp_driver ucb1x00_driver = {
701 	.drv		= {
702 		.name	= "ucb1x00",
703 	},
704 	.probe		= ucb1x00_probe,
705 	.remove		= ucb1x00_remove,
706 	.suspend	= ucb1x00_suspend,
707 	.resume		= ucb1x00_resume,
708 };
709 
710 static int __init ucb1x00_init(void)
711 {
712 	int ret = class_register(&ucb1x00_class);
713 	if (ret == 0) {
714 		ret = mcp_driver_register(&ucb1x00_driver);
715 		if (ret)
716 			class_unregister(&ucb1x00_class);
717 	}
718 	return ret;
719 }
720 
721 static void __exit ucb1x00_exit(void)
722 {
723 	mcp_driver_unregister(&ucb1x00_driver);
724 	class_unregister(&ucb1x00_class);
725 }
726 
727 module_init(ucb1x00_init);
728 module_exit(ucb1x00_exit);
729 
730 EXPORT_SYMBOL(ucb1x00_io_set_dir);
731 EXPORT_SYMBOL(ucb1x00_io_write);
732 EXPORT_SYMBOL(ucb1x00_io_read);
733 
734 EXPORT_SYMBOL(ucb1x00_adc_enable);
735 EXPORT_SYMBOL(ucb1x00_adc_read);
736 EXPORT_SYMBOL(ucb1x00_adc_disable);
737 
738 EXPORT_SYMBOL(ucb1x00_hook_irq);
739 EXPORT_SYMBOL(ucb1x00_free_irq);
740 EXPORT_SYMBOL(ucb1x00_enable_irq);
741 EXPORT_SYMBOL(ucb1x00_disable_irq);
742 
743 EXPORT_SYMBOL(ucb1x00_register_driver);
744 EXPORT_SYMBOL(ucb1x00_unregister_driver);
745 
746 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
747 MODULE_DESCRIPTION("UCB1x00 core driver");
748 MODULE_LICENSE("GPL");
749