xref: /linux/drivers/mfd/ucb1x00-core.c (revision ca994a36f585432458ead9133fcfe05440edbb7b)
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 static struct mcp_device_id ucb1x00_id[] = {
40 	{ "ucb1x00", 0 },  /* auto-detection */
41 	{ "ucb1200", UCB_ID_1200 },
42 	{ "ucb1300", UCB_ID_1300 },
43 	{ "tc35143", UCB_ID_TC35143 },
44 	{ }
45 };
46 MODULE_DEVICE_TABLE(mcp, ucb1x00_id);
47 
48 /**
49  *	ucb1x00_io_set_dir - set IO direction
50  *	@ucb: UCB1x00 structure describing chip
51  *	@in:  bitfield of IO pins to be set as inputs
52  *	@out: bitfield of IO pins to be set as outputs
53  *
54  *	Set the IO direction of the ten general purpose IO pins on
55  *	the UCB1x00 chip.  The @in bitfield has priority over the
56  *	@out bitfield, in that if you specify a pin as both input
57  *	and output, it will end up as an input.
58  *
59  *	ucb1x00_enable must have been called to enable the comms
60  *	before using this function.
61  *
62  *	This function takes a spinlock, disabling interrupts.
63  */
64 void ucb1x00_io_set_dir(struct ucb1x00 *ucb, unsigned int in, unsigned int out)
65 {
66 	unsigned long flags;
67 
68 	spin_lock_irqsave(&ucb->io_lock, flags);
69 	ucb->io_dir |= out;
70 	ucb->io_dir &= ~in;
71 
72 	ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
73 	spin_unlock_irqrestore(&ucb->io_lock, flags);
74 }
75 
76 /**
77  *	ucb1x00_io_write - set or clear IO outputs
78  *	@ucb:   UCB1x00 structure describing chip
79  *	@set:   bitfield of IO pins to set to logic '1'
80  *	@clear: bitfield of IO pins to set to logic '0'
81  *
82  *	Set the IO output state of the specified IO pins.  The value
83  *	is retained if the pins are subsequently configured as inputs.
84  *	The @clear bitfield has priority over the @set bitfield -
85  *	outputs will be cleared.
86  *
87  *	ucb1x00_enable must have been called to enable the comms
88  *	before using this function.
89  *
90  *	This function takes a spinlock, disabling interrupts.
91  */
92 void ucb1x00_io_write(struct ucb1x00 *ucb, unsigned int set, unsigned int clear)
93 {
94 	unsigned long flags;
95 
96 	spin_lock_irqsave(&ucb->io_lock, flags);
97 	ucb->io_out |= set;
98 	ucb->io_out &= ~clear;
99 
100 	ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out);
101 	spin_unlock_irqrestore(&ucb->io_lock, flags);
102 }
103 
104 /**
105  *	ucb1x00_io_read - read the current state of the IO pins
106  *	@ucb: UCB1x00 structure describing chip
107  *
108  *	Return a bitfield describing the logic state of the ten
109  *	general purpose IO pins.
110  *
111  *	ucb1x00_enable must have been called to enable the comms
112  *	before using this function.
113  *
114  *	This function does not take any semaphores or spinlocks.
115  */
116 unsigned int ucb1x00_io_read(struct ucb1x00 *ucb)
117 {
118 	return ucb1x00_reg_read(ucb, UCB_IO_DATA);
119 }
120 
121 static void ucb1x00_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
122 {
123 	struct ucb1x00 *ucb = container_of(chip, struct ucb1x00, gpio);
124 	unsigned long flags;
125 
126 	spin_lock_irqsave(&ucb->io_lock, flags);
127 	if (value)
128 		ucb->io_out |= 1 << offset;
129 	else
130 		ucb->io_out &= ~(1 << offset);
131 
132 	ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out);
133 	spin_unlock_irqrestore(&ucb->io_lock, flags);
134 }
135 
136 static int ucb1x00_gpio_get(struct gpio_chip *chip, unsigned offset)
137 {
138 	struct ucb1x00 *ucb = container_of(chip, struct ucb1x00, gpio);
139 	return ucb1x00_reg_read(ucb, UCB_IO_DATA) & (1 << offset);
140 }
141 
142 static int ucb1x00_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
143 {
144 	struct ucb1x00 *ucb = container_of(chip, struct ucb1x00, gpio);
145 	unsigned long flags;
146 
147 	spin_lock_irqsave(&ucb->io_lock, flags);
148 	ucb->io_dir &= ~(1 << offset);
149 	ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
150 	spin_unlock_irqrestore(&ucb->io_lock, flags);
151 
152 	return 0;
153 }
154 
155 static int ucb1x00_gpio_direction_output(struct gpio_chip *chip, unsigned offset
156 		, int value)
157 {
158 	struct ucb1x00 *ucb = container_of(chip, struct ucb1x00, gpio);
159 	unsigned long flags;
160 
161 	spin_lock_irqsave(&ucb->io_lock, flags);
162 	ucb->io_dir |= (1 << offset);
163 	ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
164 
165 	if (value)
166 		ucb->io_out |= 1 << offset;
167 	else
168 		ucb->io_out &= ~(1 << offset);
169 	ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out);
170 	spin_unlock_irqrestore(&ucb->io_lock, flags);
171 
172 	return 0;
173 }
174 
175 /*
176  * UCB1300 data sheet says we must:
177  *  1. enable ADC	=> 5us (including reference startup time)
178  *  2. select input	=> 51*tsibclk  => 4.3us
179  *  3. start conversion	=> 102*tsibclk => 8.5us
180  * (tsibclk = 1/11981000)
181  * Period between SIB 128-bit frames = 10.7us
182  */
183 
184 /**
185  *	ucb1x00_adc_enable - enable the ADC converter
186  *	@ucb: UCB1x00 structure describing chip
187  *
188  *	Enable the ucb1x00 and ADC converter on the UCB1x00 for use.
189  *	Any code wishing to use the ADC converter must call this
190  *	function prior to using it.
191  *
192  *	This function takes the ADC semaphore to prevent two or more
193  *	concurrent uses, and therefore may sleep.  As a result, it
194  *	can only be called from process context, not interrupt
195  *	context.
196  *
197  *	You should release the ADC as soon as possible using
198  *	ucb1x00_adc_disable.
199  */
200 void ucb1x00_adc_enable(struct ucb1x00 *ucb)
201 {
202 	down(&ucb->adc_sem);
203 
204 	ucb->adc_cr |= UCB_ADC_ENA;
205 
206 	ucb1x00_enable(ucb);
207 	ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr);
208 }
209 
210 /**
211  *	ucb1x00_adc_read - read the specified ADC channel
212  *	@ucb: UCB1x00 structure describing chip
213  *	@adc_channel: ADC channel mask
214  *	@sync: wait for syncronisation pulse.
215  *
216  *	Start an ADC conversion and wait for the result.  Note that
217  *	synchronised ADC conversions (via the ADCSYNC pin) must wait
218  *	until the trigger is asserted and the conversion is finished.
219  *
220  *	This function currently spins waiting for the conversion to
221  *	complete (2 frames max without sync).
222  *
223  *	If called for a synchronised ADC conversion, it may sleep
224  *	with the ADC semaphore held.
225  */
226 unsigned int ucb1x00_adc_read(struct ucb1x00 *ucb, int adc_channel, int sync)
227 {
228 	unsigned int val;
229 
230 	if (sync)
231 		adc_channel |= UCB_ADC_SYNC_ENA;
232 
233 	ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr | adc_channel);
234 	ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr | adc_channel | UCB_ADC_START);
235 
236 	for (;;) {
237 		val = ucb1x00_reg_read(ucb, UCB_ADC_DATA);
238 		if (val & UCB_ADC_DAT_VAL)
239 			break;
240 		/* yield to other processes */
241 		set_current_state(TASK_INTERRUPTIBLE);
242 		schedule_timeout(1);
243 	}
244 
245 	return UCB_ADC_DAT(val);
246 }
247 
248 /**
249  *	ucb1x00_adc_disable - disable the ADC converter
250  *	@ucb: UCB1x00 structure describing chip
251  *
252  *	Disable the ADC converter and release the ADC semaphore.
253  */
254 void ucb1x00_adc_disable(struct ucb1x00 *ucb)
255 {
256 	ucb->adc_cr &= ~UCB_ADC_ENA;
257 	ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr);
258 	ucb1x00_disable(ucb);
259 
260 	up(&ucb->adc_sem);
261 }
262 
263 /*
264  * UCB1x00 Interrupt handling.
265  *
266  * The UCB1x00 can generate interrupts when the SIBCLK is stopped.
267  * Since we need to read an internal register, we must re-enable
268  * SIBCLK to talk to the chip.  We leave the clock running until
269  * we have finished processing all interrupts from the chip.
270  */
271 static irqreturn_t ucb1x00_irq(int irqnr, void *devid)
272 {
273 	struct ucb1x00 *ucb = devid;
274 	struct ucb1x00_irq *irq;
275 	unsigned int isr, i;
276 
277 	ucb1x00_enable(ucb);
278 	isr = ucb1x00_reg_read(ucb, UCB_IE_STATUS);
279 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, isr);
280 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0);
281 
282 	for (i = 0, irq = ucb->irq_handler; i < 16 && isr; i++, isr >>= 1, irq++)
283 		if (isr & 1 && irq->fn)
284 			irq->fn(i, irq->devid);
285 	ucb1x00_disable(ucb);
286 
287 	return IRQ_HANDLED;
288 }
289 
290 /**
291  *	ucb1x00_hook_irq - hook a UCB1x00 interrupt
292  *	@ucb:   UCB1x00 structure describing chip
293  *	@idx:   interrupt index
294  *	@fn:    function to call when interrupt is triggered
295  *	@devid: device id to pass to interrupt handler
296  *
297  *	Hook the specified interrupt.  You can only register one handler
298  *	for each interrupt source.  The interrupt source is not enabled
299  *	by this function; use ucb1x00_enable_irq instead.
300  *
301  *	Interrupt handlers will be called with other interrupts enabled.
302  *
303  *	Returns zero on success, or one of the following errors:
304  *	 -EINVAL if the interrupt index is invalid
305  *	 -EBUSY if the interrupt has already been hooked
306  */
307 int ucb1x00_hook_irq(struct ucb1x00 *ucb, unsigned int idx, void (*fn)(int, void *), void *devid)
308 {
309 	struct ucb1x00_irq *irq;
310 	int ret = -EINVAL;
311 
312 	if (idx < 16) {
313 		irq = ucb->irq_handler + idx;
314 		ret = -EBUSY;
315 
316 		spin_lock_irq(&ucb->lock);
317 		if (irq->fn == NULL) {
318 			irq->devid = devid;
319 			irq->fn = fn;
320 			ret = 0;
321 		}
322 		spin_unlock_irq(&ucb->lock);
323 	}
324 	return ret;
325 }
326 
327 /**
328  *	ucb1x00_enable_irq - enable an UCB1x00 interrupt source
329  *	@ucb: UCB1x00 structure describing chip
330  *	@idx: interrupt index
331  *	@edges: interrupt edges to enable
332  *
333  *	Enable the specified interrupt to trigger on %UCB_RISING,
334  *	%UCB_FALLING or both edges.  The interrupt should have been
335  *	hooked by ucb1x00_hook_irq.
336  */
337 void ucb1x00_enable_irq(struct ucb1x00 *ucb, unsigned int idx, int edges)
338 {
339 	unsigned long flags;
340 
341 	if (idx < 16) {
342 		spin_lock_irqsave(&ucb->lock, flags);
343 
344 		ucb1x00_enable(ucb);
345 		if (edges & UCB_RISING) {
346 			ucb->irq_ris_enbl |= 1 << idx;
347 			ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl);
348 		}
349 		if (edges & UCB_FALLING) {
350 			ucb->irq_fal_enbl |= 1 << idx;
351 			ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl);
352 		}
353 		ucb1x00_disable(ucb);
354 		spin_unlock_irqrestore(&ucb->lock, flags);
355 	}
356 }
357 
358 /**
359  *	ucb1x00_disable_irq - disable an UCB1x00 interrupt source
360  *	@ucb: UCB1x00 structure describing chip
361  *	@edges: interrupt edges to disable
362  *
363  *	Disable the specified interrupt triggering on the specified
364  *	(%UCB_RISING, %UCB_FALLING or both) edges.
365  */
366 void ucb1x00_disable_irq(struct ucb1x00 *ucb, unsigned int idx, int edges)
367 {
368 	unsigned long flags;
369 
370 	if (idx < 16) {
371 		spin_lock_irqsave(&ucb->lock, flags);
372 
373 		ucb1x00_enable(ucb);
374 		if (edges & UCB_RISING) {
375 			ucb->irq_ris_enbl &= ~(1 << idx);
376 			ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl);
377 		}
378 		if (edges & UCB_FALLING) {
379 			ucb->irq_fal_enbl &= ~(1 << idx);
380 			ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl);
381 		}
382 		ucb1x00_disable(ucb);
383 		spin_unlock_irqrestore(&ucb->lock, flags);
384 	}
385 }
386 
387 /**
388  *	ucb1x00_free_irq - disable and free the specified UCB1x00 interrupt
389  *	@ucb: UCB1x00 structure describing chip
390  *	@idx: interrupt index
391  *	@devid: device id.
392  *
393  *	Disable the interrupt source and remove the handler.  devid must
394  *	match the devid passed when hooking the interrupt.
395  *
396  *	Returns zero on success, or one of the following errors:
397  *	 -EINVAL if the interrupt index is invalid
398  *	 -ENOENT if devid does not match
399  */
400 int ucb1x00_free_irq(struct ucb1x00 *ucb, unsigned int idx, void *devid)
401 {
402 	struct ucb1x00_irq *irq;
403 	int ret;
404 
405 	if (idx >= 16)
406 		goto bad;
407 
408 	irq = ucb->irq_handler + idx;
409 	ret = -ENOENT;
410 
411 	spin_lock_irq(&ucb->lock);
412 	if (irq->devid == devid) {
413 		ucb->irq_ris_enbl &= ~(1 << idx);
414 		ucb->irq_fal_enbl &= ~(1 << idx);
415 
416 		ucb1x00_enable(ucb);
417 		ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl);
418 		ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl);
419 		ucb1x00_disable(ucb);
420 
421 		irq->fn = NULL;
422 		irq->devid = NULL;
423 		ret = 0;
424 	}
425 	spin_unlock_irq(&ucb->lock);
426 	return ret;
427 
428 bad:
429 	printk(KERN_ERR "Freeing bad UCB1x00 irq %d\n", idx);
430 	return -EINVAL;
431 }
432 
433 static int ucb1x00_add_dev(struct ucb1x00 *ucb, struct ucb1x00_driver *drv)
434 {
435 	struct ucb1x00_dev *dev;
436 	int ret = -ENOMEM;
437 
438 	dev = kmalloc(sizeof(struct ucb1x00_dev), GFP_KERNEL);
439 	if (dev) {
440 		dev->ucb = ucb;
441 		dev->drv = drv;
442 
443 		ret = drv->add(dev);
444 
445 		if (ret == 0) {
446 			list_add(&dev->dev_node, &ucb->devs);
447 			list_add(&dev->drv_node, &drv->devs);
448 		} else {
449 			kfree(dev);
450 		}
451 	}
452 	return ret;
453 }
454 
455 static void ucb1x00_remove_dev(struct ucb1x00_dev *dev)
456 {
457 	dev->drv->remove(dev);
458 	list_del(&dev->dev_node);
459 	list_del(&dev->drv_node);
460 	kfree(dev);
461 }
462 
463 /*
464  * Try to probe our interrupt, rather than relying on lots of
465  * hard-coded machine dependencies.  For reference, the expected
466  * IRQ mappings are:
467  *
468  *  	Machine		Default IRQ
469  *	adsbitsy	IRQ_GPCIN4
470  *	cerf		IRQ_GPIO_UCB1200_IRQ
471  *	flexanet	IRQ_GPIO_GUI
472  *	freebird	IRQ_GPIO_FREEBIRD_UCB1300_IRQ
473  *	graphicsclient	ADS_EXT_IRQ(8)
474  *	graphicsmaster	ADS_EXT_IRQ(8)
475  *	lart		LART_IRQ_UCB1200
476  *	omnimeter	IRQ_GPIO23
477  *	pfs168		IRQ_GPIO_UCB1300_IRQ
478  *	simpad		IRQ_GPIO_UCB1300_IRQ
479  *	shannon		SHANNON_IRQ_GPIO_IRQ_CODEC
480  *	yopy		IRQ_GPIO_UCB1200_IRQ
481  */
482 static int ucb1x00_detect_irq(struct ucb1x00 *ucb)
483 {
484 	unsigned long mask;
485 
486 	mask = probe_irq_on();
487 	if (!mask) {
488 		probe_irq_off(mask);
489 		return NO_IRQ;
490 	}
491 
492 	/*
493 	 * Enable the ADC interrupt.
494 	 */
495 	ucb1x00_reg_write(ucb, UCB_IE_RIS, UCB_IE_ADC);
496 	ucb1x00_reg_write(ucb, UCB_IE_FAL, UCB_IE_ADC);
497 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
498 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0);
499 
500 	/*
501 	 * Cause an ADC interrupt.
502 	 */
503 	ucb1x00_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
504 	ucb1x00_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
505 
506 	/*
507 	 * Wait for the conversion to complete.
508 	 */
509 	while ((ucb1x00_reg_read(ucb, UCB_ADC_DATA) & UCB_ADC_DAT_VAL) == 0);
510 	ucb1x00_reg_write(ucb, UCB_ADC_CR, 0);
511 
512 	/*
513 	 * Disable and clear interrupt.
514 	 */
515 	ucb1x00_reg_write(ucb, UCB_IE_RIS, 0);
516 	ucb1x00_reg_write(ucb, UCB_IE_FAL, 0);
517 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
518 	ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0);
519 
520 	/*
521 	 * Read triggered interrupt.
522 	 */
523 	return probe_irq_off(mask);
524 }
525 
526 static void ucb1x00_release(struct device *dev)
527 {
528 	struct ucb1x00 *ucb = classdev_to_ucb1x00(dev);
529 	kfree(ucb);
530 }
531 
532 static struct class ucb1x00_class = {
533 	.name		= "ucb1x00",
534 	.dev_release	= ucb1x00_release,
535 };
536 
537 static int ucb1x00_probe(struct mcp *mcp)
538 {
539 	const struct mcp_device_id *mid;
540 	struct ucb1x00 *ucb;
541 	struct ucb1x00_driver *drv;
542 	struct ucb1x00_plat_data *pdata;
543 	unsigned int id;
544 	int ret = -ENODEV;
545 	int temp;
546 
547 	mcp_enable(mcp);
548 	id = mcp_reg_read(mcp, UCB_ID);
549 	mid = mcp_get_device_id(mcp);
550 
551 	if (mid && mid->driver_data) {
552 		if (id != mid->driver_data) {
553 			printk(KERN_WARNING "%s wrong ID %04x found: %04x\n",
554 				mid->name, (unsigned int) mid->driver_data, id);
555 			goto err_disable;
556 		}
557 	} else {
558 		mid = &ucb1x00_id[1];
559 		while (mid->driver_data) {
560 			if (id == mid->driver_data)
561 				break;
562 			mid++;
563 		}
564 		printk(KERN_WARNING "%s ID not found: %04x\n",
565 			ucb1x00_id[0].name, id);
566 		goto err_disable;
567 	}
568 
569 	ucb = kzalloc(sizeof(struct ucb1x00), GFP_KERNEL);
570 	ret = -ENOMEM;
571 	if (!ucb)
572 		goto err_disable;
573 
574 	pdata = mcp->attached_device.platform_data;
575 	ucb->dev.class = &ucb1x00_class;
576 	ucb->dev.parent = &mcp->attached_device;
577 	dev_set_name(&ucb->dev, mid->name);
578 
579 	spin_lock_init(&ucb->lock);
580 	spin_lock_init(&ucb->io_lock);
581 	sema_init(&ucb->adc_sem, 1);
582 
583 	ucb->id  = mid;
584 	ucb->mcp = mcp;
585 	ucb->irq = ucb1x00_detect_irq(ucb);
586 	if (ucb->irq == NO_IRQ) {
587 		printk(KERN_ERR "%s: IRQ probe failed\n", mid->name);
588 		ret = -ENODEV;
589 		goto err_free;
590 	}
591 
592 	ucb->gpio.base = -1;
593 	if (pdata && (pdata->gpio_base >= 0)) {
594 		ucb->gpio.label = dev_name(&ucb->dev);
595 		ucb->gpio.base = pdata->gpio_base;
596 		ucb->gpio.ngpio = 10;
597 		ucb->gpio.set = ucb1x00_gpio_set;
598 		ucb->gpio.get = ucb1x00_gpio_get;
599 		ucb->gpio.direction_input = ucb1x00_gpio_direction_input;
600 		ucb->gpio.direction_output = ucb1x00_gpio_direction_output;
601 		ret = gpiochip_add(&ucb->gpio);
602 		if (ret)
603 			goto err_free;
604 	} else
605 		dev_info(&ucb->dev, "gpio_base not set so no gpiolib support");
606 
607 	ret = request_irq(ucb->irq, ucb1x00_irq, IRQF_TRIGGER_RISING,
608 			  mid->name, ucb);
609 	if (ret) {
610 		printk(KERN_ERR "%s: unable to grab irq%d: %d\n",
611 			mid->name, ucb->irq, ret);
612 		goto err_gpio;
613 	}
614 
615 	mcp_set_drvdata(mcp, ucb);
616 
617 	ret = device_register(&ucb->dev);
618 	if (ret)
619 		goto err_irq;
620 
621 
622 	INIT_LIST_HEAD(&ucb->devs);
623 	mutex_lock(&ucb1x00_mutex);
624 	list_add(&ucb->node, &ucb1x00_devices);
625 	list_for_each_entry(drv, &ucb1x00_drivers, node) {
626 		ucb1x00_add_dev(ucb, drv);
627 	}
628 	mutex_unlock(&ucb1x00_mutex);
629 
630 	goto out;
631 
632  err_irq:
633 	free_irq(ucb->irq, ucb);
634  err_gpio:
635 	if (ucb->gpio.base != -1)
636 		temp = gpiochip_remove(&ucb->gpio);
637  err_free:
638 	kfree(ucb);
639  err_disable:
640 	mcp_disable(mcp);
641  out:
642 	return ret;
643 }
644 
645 static void ucb1x00_remove(struct mcp *mcp)
646 {
647 	struct ucb1x00 *ucb = mcp_get_drvdata(mcp);
648 	struct list_head *l, *n;
649 	int ret;
650 
651 	mutex_lock(&ucb1x00_mutex);
652 	list_del(&ucb->node);
653 	list_for_each_safe(l, n, &ucb->devs) {
654 		struct ucb1x00_dev *dev = list_entry(l, struct ucb1x00_dev, dev_node);
655 		ucb1x00_remove_dev(dev);
656 	}
657 	mutex_unlock(&ucb1x00_mutex);
658 
659 	if (ucb->gpio.base != -1) {
660 		ret = gpiochip_remove(&ucb->gpio);
661 		if (ret)
662 			dev_err(&ucb->dev, "Can't remove gpio chip: %d\n", ret);
663 	}
664 
665 	free_irq(ucb->irq, ucb);
666 	device_unregister(&ucb->dev);
667 }
668 
669 int ucb1x00_register_driver(struct ucb1x00_driver *drv)
670 {
671 	struct ucb1x00 *ucb;
672 
673 	INIT_LIST_HEAD(&drv->devs);
674 	mutex_lock(&ucb1x00_mutex);
675 	list_add(&drv->node, &ucb1x00_drivers);
676 	list_for_each_entry(ucb, &ucb1x00_devices, node) {
677 		ucb1x00_add_dev(ucb, drv);
678 	}
679 	mutex_unlock(&ucb1x00_mutex);
680 	return 0;
681 }
682 
683 void ucb1x00_unregister_driver(struct ucb1x00_driver *drv)
684 {
685 	struct list_head *n, *l;
686 
687 	mutex_lock(&ucb1x00_mutex);
688 	list_del(&drv->node);
689 	list_for_each_safe(l, n, &drv->devs) {
690 		struct ucb1x00_dev *dev = list_entry(l, struct ucb1x00_dev, drv_node);
691 		ucb1x00_remove_dev(dev);
692 	}
693 	mutex_unlock(&ucb1x00_mutex);
694 }
695 
696 static int ucb1x00_suspend(struct mcp *mcp, pm_message_t state)
697 {
698 	struct ucb1x00 *ucb = mcp_get_drvdata(mcp);
699 	struct ucb1x00_dev *dev;
700 
701 	mutex_lock(&ucb1x00_mutex);
702 	list_for_each_entry(dev, &ucb->devs, dev_node) {
703 		if (dev->drv->suspend)
704 			dev->drv->suspend(dev, state);
705 	}
706 	mutex_unlock(&ucb1x00_mutex);
707 	return 0;
708 }
709 
710 static int ucb1x00_resume(struct mcp *mcp)
711 {
712 	struct ucb1x00 *ucb = mcp_get_drvdata(mcp);
713 	struct ucb1x00_dev *dev;
714 
715 	ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
716 	mutex_lock(&ucb1x00_mutex);
717 	list_for_each_entry(dev, &ucb->devs, dev_node) {
718 		if (dev->drv->resume)
719 			dev->drv->resume(dev);
720 	}
721 	mutex_unlock(&ucb1x00_mutex);
722 	return 0;
723 }
724 
725 static struct mcp_driver ucb1x00_driver = {
726 	.drv		= {
727 		.name	= "ucb1x00",
728 	},
729 	.probe		= ucb1x00_probe,
730 	.remove		= ucb1x00_remove,
731 	.suspend	= ucb1x00_suspend,
732 	.resume		= ucb1x00_resume,
733 	.id_table	= ucb1x00_id,
734 };
735 
736 static int __init ucb1x00_init(void)
737 {
738 	int ret = class_register(&ucb1x00_class);
739 	if (ret == 0) {
740 		ret = mcp_driver_register(&ucb1x00_driver);
741 		if (ret)
742 			class_unregister(&ucb1x00_class);
743 	}
744 	return ret;
745 }
746 
747 static void __exit ucb1x00_exit(void)
748 {
749 	mcp_driver_unregister(&ucb1x00_driver);
750 	class_unregister(&ucb1x00_class);
751 }
752 
753 module_init(ucb1x00_init);
754 module_exit(ucb1x00_exit);
755 
756 EXPORT_SYMBOL(ucb1x00_io_set_dir);
757 EXPORT_SYMBOL(ucb1x00_io_write);
758 EXPORT_SYMBOL(ucb1x00_io_read);
759 
760 EXPORT_SYMBOL(ucb1x00_adc_enable);
761 EXPORT_SYMBOL(ucb1x00_adc_read);
762 EXPORT_SYMBOL(ucb1x00_adc_disable);
763 
764 EXPORT_SYMBOL(ucb1x00_hook_irq);
765 EXPORT_SYMBOL(ucb1x00_free_irq);
766 EXPORT_SYMBOL(ucb1x00_enable_irq);
767 EXPORT_SYMBOL(ucb1x00_disable_irq);
768 
769 EXPORT_SYMBOL(ucb1x00_register_driver);
770 EXPORT_SYMBOL(ucb1x00_unregister_driver);
771 
772 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
773 MODULE_DESCRIPTION("UCB1x00 core driver");
774 MODULE_LICENSE("GPL");
775