xref: /openbmc/linux/drivers/mfd/ucb1x00-core.c (revision 275876e2)
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/irq.h>
27 #include <linux/device.h>
28 #include <linux/mutex.h>
29 #include <linux/mfd/ucb1x00.h>
30 #include <linux/pm.h>
31 #include <linux/gpio.h>
32 
33 static DEFINE_MUTEX(ucb1x00_mutex);
34 static LIST_HEAD(ucb1x00_drivers);
35 static LIST_HEAD(ucb1x00_devices);
36 
37 /**
38  *	ucb1x00_io_set_dir - set IO direction
39  *	@ucb: UCB1x00 structure describing chip
40  *	@in:  bitfield of IO pins to be set as inputs
41  *	@out: bitfield of IO pins to be set as outputs
42  *
43  *	Set the IO direction of the ten general purpose IO pins on
44  *	the UCB1x00 chip.  The @in bitfield has priority over the
45  *	@out bitfield, in that if you specify a pin as both input
46  *	and output, it will end up as an input.
47  *
48  *	ucb1x00_enable must have been called to enable the comms
49  *	before using this function.
50  *
51  *	This function takes a spinlock, disabling interrupts.
52  */
53 void ucb1x00_io_set_dir(struct ucb1x00 *ucb, unsigned int in, unsigned int out)
54 {
55 	unsigned long flags;
56 
57 	spin_lock_irqsave(&ucb->io_lock, flags);
58 	ucb->io_dir |= out;
59 	ucb->io_dir &= ~in;
60 
61 	ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
62 	spin_unlock_irqrestore(&ucb->io_lock, flags);
63 }
64 
65 /**
66  *	ucb1x00_io_write - set or clear IO outputs
67  *	@ucb:   UCB1x00 structure describing chip
68  *	@set:   bitfield of IO pins to set to logic '1'
69  *	@clear: bitfield of IO pins to set to logic '0'
70  *
71  *	Set the IO output state of the specified IO pins.  The value
72  *	is retained if the pins are subsequently configured as inputs.
73  *	The @clear bitfield has priority over the @set bitfield -
74  *	outputs will be cleared.
75  *
76  *	ucb1x00_enable must have been called to enable the comms
77  *	before using this function.
78  *
79  *	This function takes a spinlock, disabling interrupts.
80  */
81 void ucb1x00_io_write(struct ucb1x00 *ucb, unsigned int set, unsigned int clear)
82 {
83 	unsigned long flags;
84 
85 	spin_lock_irqsave(&ucb->io_lock, flags);
86 	ucb->io_out |= set;
87 	ucb->io_out &= ~clear;
88 
89 	ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out);
90 	spin_unlock_irqrestore(&ucb->io_lock, flags);
91 }
92 
93 /**
94  *	ucb1x00_io_read - read the current state of the IO pins
95  *	@ucb: UCB1x00 structure describing chip
96  *
97  *	Return a bitfield describing the logic state of the ten
98  *	general purpose IO pins.
99  *
100  *	ucb1x00_enable must have been called to enable the comms
101  *	before using this function.
102  *
103  *	This function does not take any mutexes or spinlocks.
104  */
105 unsigned int ucb1x00_io_read(struct ucb1x00 *ucb)
106 {
107 	return ucb1x00_reg_read(ucb, UCB_IO_DATA);
108 }
109 
110 static void ucb1x00_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
111 {
112 	struct ucb1x00 *ucb = container_of(chip, struct ucb1x00, gpio);
113 	unsigned long flags;
114 
115 	spin_lock_irqsave(&ucb->io_lock, flags);
116 	if (value)
117 		ucb->io_out |= 1 << offset;
118 	else
119 		ucb->io_out &= ~(1 << offset);
120 
121 	ucb1x00_enable(ucb);
122 	ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out);
123 	ucb1x00_disable(ucb);
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 	unsigned val;
131 
132 	ucb1x00_enable(ucb);
133 	val = ucb1x00_reg_read(ucb, UCB_IO_DATA);
134 	ucb1x00_disable(ucb);
135 
136 	return val & (1 << offset);
137 }
138 
139 static int ucb1x00_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
140 {
141 	struct ucb1x00 *ucb = container_of(chip, struct ucb1x00, gpio);
142 	unsigned long flags;
143 
144 	spin_lock_irqsave(&ucb->io_lock, flags);
145 	ucb->io_dir &= ~(1 << offset);
146 	ucb1x00_enable(ucb);
147 	ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
148 	ucb1x00_disable(ucb);
149 	spin_unlock_irqrestore(&ucb->io_lock, flags);
150 
151 	return 0;
152 }
153 
154 static int ucb1x00_gpio_direction_output(struct gpio_chip *chip, unsigned offset
155 		, int value)
156 {
157 	struct ucb1x00 *ucb = container_of(chip, struct ucb1x00, gpio);
158 	unsigned long flags;
159 	unsigned old, mask = 1 << offset;
160 
161 	spin_lock_irqsave(&ucb->io_lock, flags);
162 	old = ucb->io_out;
163 	if (value)
164 		ucb->io_out |= mask;
165 	else
166 		ucb->io_out &= ~mask;
167 
168 	ucb1x00_enable(ucb);
169 	if (old != ucb->io_out)
170 		ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out);
171 
172 	if (!(ucb->io_dir & mask)) {
173 		ucb->io_dir |= mask;
174 		ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
175 	}
176 	ucb1x00_disable(ucb);
177 	spin_unlock_irqrestore(&ucb->io_lock, flags);
178 
179 	return 0;
180 }
181 
182 static int ucb1x00_to_irq(struct gpio_chip *chip, unsigned offset)
183 {
184 	struct ucb1x00 *ucb = container_of(chip, struct ucb1x00, gpio);
185 
186 	return ucb->irq_base > 0 ? ucb->irq_base + offset : -ENXIO;
187 }
188 
189 /*
190  * UCB1300 data sheet says we must:
191  *  1. enable ADC	=> 5us (including reference startup time)
192  *  2. select input	=> 51*tsibclk  => 4.3us
193  *  3. start conversion	=> 102*tsibclk => 8.5us
194  * (tsibclk = 1/11981000)
195  * Period between SIB 128-bit frames = 10.7us
196  */
197 
198 /**
199  *	ucb1x00_adc_enable - enable the ADC converter
200  *	@ucb: UCB1x00 structure describing chip
201  *
202  *	Enable the ucb1x00 and ADC converter on the UCB1x00 for use.
203  *	Any code wishing to use the ADC converter must call this
204  *	function prior to using it.
205  *
206  *	This function takes the ADC mutex to prevent two or more
207  *	concurrent uses, and therefore may sleep.  As a result, it
208  *	can only be called from process context, not interrupt
209  *	context.
210  *
211  *	You should release the ADC as soon as possible using
212  *	ucb1x00_adc_disable.
213  */
214 void ucb1x00_adc_enable(struct ucb1x00 *ucb)
215 {
216 	mutex_lock(&ucb->adc_mutex);
217 
218 	ucb->adc_cr |= UCB_ADC_ENA;
219 
220 	ucb1x00_enable(ucb);
221 	ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr);
222 }
223 
224 /**
225  *	ucb1x00_adc_read - read the specified ADC channel
226  *	@ucb: UCB1x00 structure describing chip
227  *	@adc_channel: ADC channel mask
228  *	@sync: wait for syncronisation pulse.
229  *
230  *	Start an ADC conversion and wait for the result.  Note that
231  *	synchronised ADC conversions (via the ADCSYNC pin) must wait
232  *	until the trigger is asserted and the conversion is finished.
233  *
234  *	This function currently spins waiting for the conversion to
235  *	complete (2 frames max without sync).
236  *
237  *	If called for a synchronised ADC conversion, it may sleep
238  *	with the ADC mutex held.
239  */
240 unsigned int ucb1x00_adc_read(struct ucb1x00 *ucb, int adc_channel, int sync)
241 {
242 	unsigned int val;
243 
244 	if (sync)
245 		adc_channel |= UCB_ADC_SYNC_ENA;
246 
247 	ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr | adc_channel);
248 	ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr | adc_channel | UCB_ADC_START);
249 
250 	for (;;) {
251 		val = ucb1x00_reg_read(ucb, UCB_ADC_DATA);
252 		if (val & UCB_ADC_DAT_VAL)
253 			break;
254 		/* yield to other processes */
255 		set_current_state(TASK_INTERRUPTIBLE);
256 		schedule_timeout(1);
257 	}
258 
259 	return UCB_ADC_DAT(val);
260 }
261 
262 /**
263  *	ucb1x00_adc_disable - disable the ADC converter
264  *	@ucb: UCB1x00 structure describing chip
265  *
266  *	Disable the ADC converter and release the ADC mutex.
267  */
268 void ucb1x00_adc_disable(struct ucb1x00 *ucb)
269 {
270 	ucb->adc_cr &= ~UCB_ADC_ENA;
271 	ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr);
272 	ucb1x00_disable(ucb);
273 
274 	mutex_unlock(&ucb->adc_mutex);
275 }
276 
277 /*
278  * UCB1x00 Interrupt handling.
279  *
280  * The UCB1x00 can generate interrupts when the SIBCLK is stopped.
281  * Since we need to read an internal register, we must re-enable
282  * SIBCLK to talk to the chip.  We leave the clock running until
283  * we have finished processing all interrupts from the chip.
284  */
285 static void ucb1x00_irq(unsigned int irq, struct irq_desc *desc)
286 {
287 	struct ucb1x00 *ucb = irq_desc_get_handler_data(desc);
288 	unsigned int isr, i;
289 
290 	ucb1x00_enable(ucb);
291 	isr = ucb1x00_reg_read(ucb, UCB_IE_STATUS);
292 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, isr);
293 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0);
294 
295 	for (i = 0; i < 16 && isr; i++, isr >>= 1, irq++)
296 		if (isr & 1)
297 			generic_handle_irq(ucb->irq_base + i);
298 	ucb1x00_disable(ucb);
299 }
300 
301 static void ucb1x00_irq_update(struct ucb1x00 *ucb, unsigned mask)
302 {
303 	ucb1x00_enable(ucb);
304 	if (ucb->irq_ris_enbl & mask)
305 		ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl &
306 				  ucb->irq_mask);
307 	if (ucb->irq_fal_enbl & mask)
308 		ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl &
309 				  ucb->irq_mask);
310 	ucb1x00_disable(ucb);
311 }
312 
313 static void ucb1x00_irq_noop(struct irq_data *data)
314 {
315 }
316 
317 static void ucb1x00_irq_mask(struct irq_data *data)
318 {
319 	struct ucb1x00 *ucb = irq_data_get_irq_chip_data(data);
320 	unsigned mask = 1 << (data->irq - ucb->irq_base);
321 
322 	raw_spin_lock(&ucb->irq_lock);
323 	ucb->irq_mask &= ~mask;
324 	ucb1x00_irq_update(ucb, mask);
325 	raw_spin_unlock(&ucb->irq_lock);
326 }
327 
328 static void ucb1x00_irq_unmask(struct irq_data *data)
329 {
330 	struct ucb1x00 *ucb = irq_data_get_irq_chip_data(data);
331 	unsigned mask = 1 << (data->irq - ucb->irq_base);
332 
333 	raw_spin_lock(&ucb->irq_lock);
334 	ucb->irq_mask |= mask;
335 	ucb1x00_irq_update(ucb, mask);
336 	raw_spin_unlock(&ucb->irq_lock);
337 }
338 
339 static int ucb1x00_irq_set_type(struct irq_data *data, unsigned int type)
340 {
341 	struct ucb1x00 *ucb = irq_data_get_irq_chip_data(data);
342 	unsigned mask = 1 << (data->irq - ucb->irq_base);
343 
344 	raw_spin_lock(&ucb->irq_lock);
345 	if (type & IRQ_TYPE_EDGE_RISING)
346 		ucb->irq_ris_enbl |= mask;
347 	else
348 		ucb->irq_ris_enbl &= ~mask;
349 
350 	if (type & IRQ_TYPE_EDGE_FALLING)
351 		ucb->irq_fal_enbl |= mask;
352 	else
353 		ucb->irq_fal_enbl &= ~mask;
354 	if (ucb->irq_mask & mask) {
355 		ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl &
356 				  ucb->irq_mask);
357 		ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl &
358 				  ucb->irq_mask);
359 	}
360 	raw_spin_unlock(&ucb->irq_lock);
361 
362 	return 0;
363 }
364 
365 static int ucb1x00_irq_set_wake(struct irq_data *data, unsigned int on)
366 {
367 	struct ucb1x00 *ucb = irq_data_get_irq_chip_data(data);
368 	struct ucb1x00_plat_data *pdata = ucb->mcp->attached_device.platform_data;
369 	unsigned mask = 1 << (data->irq - ucb->irq_base);
370 
371 	if (!pdata || !pdata->can_wakeup)
372 		return -EINVAL;
373 
374 	raw_spin_lock(&ucb->irq_lock);
375 	if (on)
376 		ucb->irq_wake |= mask;
377 	else
378 		ucb->irq_wake &= ~mask;
379 	raw_spin_unlock(&ucb->irq_lock);
380 
381 	return 0;
382 }
383 
384 static struct irq_chip ucb1x00_irqchip = {
385 	.name = "ucb1x00",
386 	.irq_ack = ucb1x00_irq_noop,
387 	.irq_mask = ucb1x00_irq_mask,
388 	.irq_unmask = ucb1x00_irq_unmask,
389 	.irq_set_type = ucb1x00_irq_set_type,
390 	.irq_set_wake = ucb1x00_irq_set_wake,
391 };
392 
393 static int ucb1x00_add_dev(struct ucb1x00 *ucb, struct ucb1x00_driver *drv)
394 {
395 	struct ucb1x00_dev *dev;
396 	int ret;
397 
398 	dev = kmalloc(sizeof(struct ucb1x00_dev), GFP_KERNEL);
399 	if (!dev)
400 		return -ENOMEM;
401 
402 	dev->ucb = ucb;
403 	dev->drv = drv;
404 
405 	ret = drv->add(dev);
406 	if (ret) {
407 		kfree(dev);
408 		return ret;
409 	}
410 
411 	list_add_tail(&dev->dev_node, &ucb->devs);
412 	list_add_tail(&dev->drv_node, &drv->devs);
413 
414 	return ret;
415 }
416 
417 static void ucb1x00_remove_dev(struct ucb1x00_dev *dev)
418 {
419 	dev->drv->remove(dev);
420 	list_del(&dev->dev_node);
421 	list_del(&dev->drv_node);
422 	kfree(dev);
423 }
424 
425 /*
426  * Try to probe our interrupt, rather than relying on lots of
427  * hard-coded machine dependencies.  For reference, the expected
428  * IRQ mappings are:
429  *
430  *  	Machine		Default IRQ
431  *	adsbitsy	IRQ_GPCIN4
432  *	cerf		IRQ_GPIO_UCB1200_IRQ
433  *	flexanet	IRQ_GPIO_GUI
434  *	freebird	IRQ_GPIO_FREEBIRD_UCB1300_IRQ
435  *	graphicsclient	ADS_EXT_IRQ(8)
436  *	graphicsmaster	ADS_EXT_IRQ(8)
437  *	lart		LART_IRQ_UCB1200
438  *	omnimeter	IRQ_GPIO23
439  *	pfs168		IRQ_GPIO_UCB1300_IRQ
440  *	simpad		IRQ_GPIO_UCB1300_IRQ
441  *	shannon		SHANNON_IRQ_GPIO_IRQ_CODEC
442  *	yopy		IRQ_GPIO_UCB1200_IRQ
443  */
444 static int ucb1x00_detect_irq(struct ucb1x00 *ucb)
445 {
446 	unsigned long mask;
447 
448 	mask = probe_irq_on();
449 	if (!mask) {
450 		probe_irq_off(mask);
451 		return NO_IRQ;
452 	}
453 
454 	/*
455 	 * Enable the ADC interrupt.
456 	 */
457 	ucb1x00_reg_write(ucb, UCB_IE_RIS, UCB_IE_ADC);
458 	ucb1x00_reg_write(ucb, UCB_IE_FAL, UCB_IE_ADC);
459 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
460 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0);
461 
462 	/*
463 	 * Cause an ADC interrupt.
464 	 */
465 	ucb1x00_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
466 	ucb1x00_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
467 
468 	/*
469 	 * Wait for the conversion to complete.
470 	 */
471 	while ((ucb1x00_reg_read(ucb, UCB_ADC_DATA) & UCB_ADC_DAT_VAL) == 0);
472 	ucb1x00_reg_write(ucb, UCB_ADC_CR, 0);
473 
474 	/*
475 	 * Disable and clear interrupt.
476 	 */
477 	ucb1x00_reg_write(ucb, UCB_IE_RIS, 0);
478 	ucb1x00_reg_write(ucb, UCB_IE_FAL, 0);
479 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
480 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0);
481 
482 	/*
483 	 * Read triggered interrupt.
484 	 */
485 	return probe_irq_off(mask);
486 }
487 
488 static void ucb1x00_release(struct device *dev)
489 {
490 	struct ucb1x00 *ucb = classdev_to_ucb1x00(dev);
491 	kfree(ucb);
492 }
493 
494 static struct class ucb1x00_class = {
495 	.name		= "ucb1x00",
496 	.dev_release	= ucb1x00_release,
497 };
498 
499 static int ucb1x00_probe(struct mcp *mcp)
500 {
501 	struct ucb1x00_plat_data *pdata = mcp->attached_device.platform_data;
502 	struct ucb1x00_driver *drv;
503 	struct ucb1x00 *ucb;
504 	unsigned id, i, irq_base;
505 	int ret = -ENODEV;
506 
507 	/* Tell the platform to deassert the UCB1x00 reset */
508 	if (pdata && pdata->reset)
509 		pdata->reset(UCB_RST_PROBE);
510 
511 	mcp_enable(mcp);
512 	id = mcp_reg_read(mcp, UCB_ID);
513 	mcp_disable(mcp);
514 
515 	if (id != UCB_ID_1200 && id != UCB_ID_1300 && id != UCB_ID_TC35143) {
516 		printk(KERN_WARNING "UCB1x00 ID not found: %04x\n", id);
517 		goto out;
518 	}
519 
520 	ucb = kzalloc(sizeof(struct ucb1x00), GFP_KERNEL);
521 	ret = -ENOMEM;
522 	if (!ucb)
523 		goto out;
524 
525 	device_initialize(&ucb->dev);
526 	ucb->dev.class = &ucb1x00_class;
527 	ucb->dev.parent = &mcp->attached_device;
528 	dev_set_name(&ucb->dev, "ucb1x00");
529 
530 	raw_spin_lock_init(&ucb->irq_lock);
531 	spin_lock_init(&ucb->io_lock);
532 	mutex_init(&ucb->adc_mutex);
533 
534 	ucb->id  = id;
535 	ucb->mcp = mcp;
536 
537 	ret = device_add(&ucb->dev);
538 	if (ret)
539 		goto err_dev_add;
540 
541 	ucb1x00_enable(ucb);
542 	ucb->irq = ucb1x00_detect_irq(ucb);
543 	ucb1x00_disable(ucb);
544 	if (ucb->irq == NO_IRQ) {
545 		dev_err(&ucb->dev, "IRQ probe failed\n");
546 		ret = -ENODEV;
547 		goto err_no_irq;
548 	}
549 
550 	ucb->gpio.base = -1;
551 	irq_base = pdata ? pdata->irq_base : 0;
552 	ucb->irq_base = irq_alloc_descs(-1, irq_base, 16, -1);
553 	if (ucb->irq_base < 0) {
554 		dev_err(&ucb->dev, "unable to allocate 16 irqs: %d\n",
555 			ucb->irq_base);
556 		ret = ucb->irq_base;
557 		goto err_irq_alloc;
558 	}
559 
560 	for (i = 0; i < 16; i++) {
561 		unsigned irq = ucb->irq_base + i;
562 
563 		irq_set_chip_and_handler(irq, &ucb1x00_irqchip, handle_edge_irq);
564 		irq_set_chip_data(irq, ucb);
565 		set_irq_flags(irq, IRQF_VALID | IRQ_NOREQUEST);
566 	}
567 
568 	irq_set_irq_type(ucb->irq, IRQ_TYPE_EDGE_RISING);
569 	irq_set_handler_data(ucb->irq, ucb);
570 	irq_set_chained_handler(ucb->irq, ucb1x00_irq);
571 
572 	if (pdata && pdata->gpio_base) {
573 		ucb->gpio.label = dev_name(&ucb->dev);
574 		ucb->gpio.dev = &ucb->dev;
575 		ucb->gpio.owner = THIS_MODULE;
576 		ucb->gpio.base = pdata->gpio_base;
577 		ucb->gpio.ngpio = 10;
578 		ucb->gpio.set = ucb1x00_gpio_set;
579 		ucb->gpio.get = ucb1x00_gpio_get;
580 		ucb->gpio.direction_input = ucb1x00_gpio_direction_input;
581 		ucb->gpio.direction_output = ucb1x00_gpio_direction_output;
582 		ucb->gpio.to_irq = ucb1x00_to_irq;
583 		ret = gpiochip_add(&ucb->gpio);
584 		if (ret)
585 			goto err_gpio_add;
586 	} else
587 		dev_info(&ucb->dev, "gpio_base not set so no gpiolib support");
588 
589 	mcp_set_drvdata(mcp, ucb);
590 
591 	if (pdata)
592 		device_set_wakeup_capable(&ucb->dev, pdata->can_wakeup);
593 
594 	INIT_LIST_HEAD(&ucb->devs);
595 	mutex_lock(&ucb1x00_mutex);
596 	list_add_tail(&ucb->node, &ucb1x00_devices);
597 	list_for_each_entry(drv, &ucb1x00_drivers, node) {
598 		ucb1x00_add_dev(ucb, drv);
599 	}
600 	mutex_unlock(&ucb1x00_mutex);
601 
602 	return ret;
603 
604  err_gpio_add:
605 	irq_set_chained_handler(ucb->irq, NULL);
606  err_irq_alloc:
607 	if (ucb->irq_base > 0)
608 		irq_free_descs(ucb->irq_base, 16);
609  err_no_irq:
610 	device_del(&ucb->dev);
611  err_dev_add:
612 	put_device(&ucb->dev);
613  out:
614 	if (pdata && pdata->reset)
615 		pdata->reset(UCB_RST_PROBE_FAIL);
616 	return ret;
617 }
618 
619 static void ucb1x00_remove(struct mcp *mcp)
620 {
621 	struct ucb1x00_plat_data *pdata = mcp->attached_device.platform_data;
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 	irq_set_chained_handler(ucb->irq, NULL);
641 	irq_free_descs(ucb->irq_base, 16);
642 	device_unregister(&ucb->dev);
643 
644 	if (pdata && pdata->reset)
645 		pdata->reset(UCB_RST_REMOVE);
646 }
647 
648 int ucb1x00_register_driver(struct ucb1x00_driver *drv)
649 {
650 	struct ucb1x00 *ucb;
651 
652 	INIT_LIST_HEAD(&drv->devs);
653 	mutex_lock(&ucb1x00_mutex);
654 	list_add_tail(&drv->node, &ucb1x00_drivers);
655 	list_for_each_entry(ucb, &ucb1x00_devices, node) {
656 		ucb1x00_add_dev(ucb, drv);
657 	}
658 	mutex_unlock(&ucb1x00_mutex);
659 	return 0;
660 }
661 
662 void ucb1x00_unregister_driver(struct ucb1x00_driver *drv)
663 {
664 	struct list_head *n, *l;
665 
666 	mutex_lock(&ucb1x00_mutex);
667 	list_del(&drv->node);
668 	list_for_each_safe(l, n, &drv->devs) {
669 		struct ucb1x00_dev *dev = list_entry(l, struct ucb1x00_dev, drv_node);
670 		ucb1x00_remove_dev(dev);
671 	}
672 	mutex_unlock(&ucb1x00_mutex);
673 }
674 
675 #ifdef CONFIG_PM_SLEEP
676 static int ucb1x00_suspend(struct device *dev)
677 {
678 	struct ucb1x00_plat_data *pdata = dev_get_platdata(dev);
679 	struct ucb1x00 *ucb = dev_get_drvdata(dev);
680 	struct ucb1x00_dev *udev;
681 
682 	mutex_lock(&ucb1x00_mutex);
683 	list_for_each_entry(udev, &ucb->devs, dev_node) {
684 		if (udev->drv->suspend)
685 			udev->drv->suspend(udev);
686 	}
687 	mutex_unlock(&ucb1x00_mutex);
688 
689 	if (ucb->irq_wake) {
690 		unsigned long flags;
691 
692 		raw_spin_lock_irqsave(&ucb->irq_lock, flags);
693 		ucb1x00_enable(ucb);
694 		ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl &
695 				  ucb->irq_wake);
696 		ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl &
697 				  ucb->irq_wake);
698 		ucb1x00_disable(ucb);
699 		raw_spin_unlock_irqrestore(&ucb->irq_lock, flags);
700 
701 		enable_irq_wake(ucb->irq);
702 	} else if (pdata && pdata->reset)
703 		pdata->reset(UCB_RST_SUSPEND);
704 
705 	return 0;
706 }
707 
708 static int ucb1x00_resume(struct device *dev)
709 {
710 	struct ucb1x00_plat_data *pdata = dev_get_platdata(dev);
711 	struct ucb1x00 *ucb = dev_get_drvdata(dev);
712 	struct ucb1x00_dev *udev;
713 
714 	if (!ucb->irq_wake && pdata && pdata->reset)
715 		pdata->reset(UCB_RST_RESUME);
716 
717 	ucb1x00_enable(ucb);
718 	ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out);
719 	ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
720 
721 	if (ucb->irq_wake) {
722 		unsigned long flags;
723 
724 		raw_spin_lock_irqsave(&ucb->irq_lock, flags);
725 		ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl &
726 				  ucb->irq_mask);
727 		ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl &
728 				  ucb->irq_mask);
729 		raw_spin_unlock_irqrestore(&ucb->irq_lock, flags);
730 
731 		disable_irq_wake(ucb->irq);
732 	}
733 	ucb1x00_disable(ucb);
734 
735 	mutex_lock(&ucb1x00_mutex);
736 	list_for_each_entry(udev, &ucb->devs, dev_node) {
737 		if (udev->drv->resume)
738 			udev->drv->resume(udev);
739 	}
740 	mutex_unlock(&ucb1x00_mutex);
741 	return 0;
742 }
743 #endif
744 
745 static SIMPLE_DEV_PM_OPS(ucb1x00_pm_ops, ucb1x00_suspend, ucb1x00_resume);
746 
747 static struct mcp_driver ucb1x00_driver = {
748 	.drv		= {
749 		.name	= "ucb1x00",
750 		.owner	= THIS_MODULE,
751 		.pm	= &ucb1x00_pm_ops,
752 	},
753 	.probe		= ucb1x00_probe,
754 	.remove		= ucb1x00_remove,
755 };
756 
757 static int __init ucb1x00_init(void)
758 {
759 	int ret = class_register(&ucb1x00_class);
760 	if (ret == 0) {
761 		ret = mcp_driver_register(&ucb1x00_driver);
762 		if (ret)
763 			class_unregister(&ucb1x00_class);
764 	}
765 	return ret;
766 }
767 
768 static void __exit ucb1x00_exit(void)
769 {
770 	mcp_driver_unregister(&ucb1x00_driver);
771 	class_unregister(&ucb1x00_class);
772 }
773 
774 module_init(ucb1x00_init);
775 module_exit(ucb1x00_exit);
776 
777 EXPORT_SYMBOL(ucb1x00_io_set_dir);
778 EXPORT_SYMBOL(ucb1x00_io_write);
779 EXPORT_SYMBOL(ucb1x00_io_read);
780 
781 EXPORT_SYMBOL(ucb1x00_adc_enable);
782 EXPORT_SYMBOL(ucb1x00_adc_read);
783 EXPORT_SYMBOL(ucb1x00_adc_disable);
784 
785 EXPORT_SYMBOL(ucb1x00_register_driver);
786 EXPORT_SYMBOL(ucb1x00_unregister_driver);
787 
788 MODULE_ALIAS("mcp:ucb1x00");
789 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
790 MODULE_DESCRIPTION("UCB1x00 core driver");
791 MODULE_LICENSE("GPL");
792