summaryrefslogtreecommitdiff
path: root/drivers/pinctrl/pinctrl-coh901.c
blob: 152efae3df8f39637f0ea750c90ca7dd99464170 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
/*
 * U300 GPIO module.
 *
 * Copyright (C) 2007-2012 ST-Ericsson AB
 * License terms: GNU General Public License (GPL) version 2
 * COH 901 571/3 - Used in DB3210 (U365 2.0) and DB3350 (U335 1.0)
 * Author: Linus Walleij <linus.walleij@linaro.org>
 * Author: Jonas Aaberg <jonas.aberg@stericsson.com>
 */
#include <linux/module.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/irqdomain.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pinctrl/pinconf-generic.h>
#include <linux/platform_data/pinctrl-coh901.h>
#include "pinctrl-coh901.h"

#define U300_GPIO_PORT_STRIDE				(0x30)
/*
 * Control Register 32bit (R/W)
 * bit 15-9 (mask 0x0000FE00) contains the number of cores. 8*cores
 * gives the number of GPIO pins.
 * bit 8-2  (mask 0x000001FC) contains the core version ID.
 */
#define U300_GPIO_CR					(0x00)
#define U300_GPIO_CR_SYNC_SEL_ENABLE			(0x00000002UL)
#define U300_GPIO_CR_BLOCK_CLKRQ_ENABLE			(0x00000001UL)
#define U300_GPIO_PXPDIR				(0x04)
#define U300_GPIO_PXPDOR				(0x08)
#define U300_GPIO_PXPCR					(0x0C)
#define U300_GPIO_PXPCR_ALL_PINS_MODE_MASK		(0x0000FFFFUL)
#define U300_GPIO_PXPCR_PIN_MODE_MASK			(0x00000003UL)
#define U300_GPIO_PXPCR_PIN_MODE_SHIFT			(0x00000002UL)
#define U300_GPIO_PXPCR_PIN_MODE_INPUT			(0x00000000UL)
#define U300_GPIO_PXPCR_PIN_MODE_OUTPUT_PUSH_PULL	(0x00000001UL)
#define U300_GPIO_PXPCR_PIN_MODE_OUTPUT_OPEN_DRAIN	(0x00000002UL)
#define U300_GPIO_PXPCR_PIN_MODE_OUTPUT_OPEN_SOURCE	(0x00000003UL)
#define U300_GPIO_PXPER					(0x10)
#define U300_GPIO_PXPER_ALL_PULL_UP_DISABLE_MASK	(0x000000FFUL)
#define U300_GPIO_PXPER_PULL_UP_DISABLE			(0x00000001UL)
#define U300_GPIO_PXIEV					(0x14)
#define U300_GPIO_PXIEN					(0x18)
#define U300_GPIO_PXIFR					(0x1C)
#define U300_GPIO_PXICR					(0x20)
#define U300_GPIO_PXICR_ALL_IRQ_CONFIG_MASK		(0x000000FFUL)
#define U300_GPIO_PXICR_IRQ_CONFIG_MASK			(0x00000001UL)
#define U300_GPIO_PXICR_IRQ_CONFIG_FALLING_EDGE		(0x00000000UL)
#define U300_GPIO_PXICR_IRQ_CONFIG_RISING_EDGE		(0x00000001UL)

/* 8 bits per port, no version has more than 7 ports */
#define U300_GPIO_PINS_PER_PORT 8
#define U300_GPIO_MAX (U300_GPIO_PINS_PER_PORT * 7)

struct u300_gpio {
	struct gpio_chip chip;
	struct list_head port_list;
	struct clk *clk;
	struct resource *memres;
	void __iomem *base;
	struct device *dev;
	u32 stride;
	/* Register offsets */
	u32 pcr;
	u32 dor;
	u32 dir;
	u32 per;
	u32 icr;
	u32 ien;
	u32 iev;
};

struct u300_gpio_port {
	struct list_head node;
	struct u300_gpio *gpio;
	char name[8];
	struct irq_domain *domain;
	int irq;
	int number;
	u8 toggle_edge_mode;
};

/*
 * Macro to expand to read a specific register found in the "gpio"
 * struct. It requires the struct u300_gpio *gpio variable to exist in
 * its context. It calculates the port offset from the given pin
 * offset, muliplies by the port stride and adds the register offset
 * so it provides a pointer to the desired register.
 */
#define U300_PIN_REG(pin, reg) \
	(gpio->base + (pin >> 3) * gpio->stride + gpio->reg)

/*
 * Provides a bitmask for a specific gpio pin inside an 8-bit GPIO
 * register.
 */
#define U300_PIN_BIT(pin) \
	(1 << (pin & 0x07))

struct u300_gpio_confdata {
	u16 bias_mode;
	bool output;
	int outval;
};

/* BS335 has seven ports of 8 bits each = GPIO pins 0..55 */
#define BS335_GPIO_NUM_PORTS 7

#define U300_FLOATING_INPUT { \
	.bias_mode = PIN_CONFIG_BIAS_HIGH_IMPEDANCE, \
	.output = false, \
}

#define U300_PULL_UP_INPUT { \
	.bias_mode = PIN_CONFIG_BIAS_PULL_UP, \
	.output = false, \
}

#define U300_OUTPUT_LOW { \
	.output = true, \
	.outval = 0, \
}

#define U300_OUTPUT_HIGH { \
	.output = true, \
	.outval = 1, \
}

/* Initial configuration */
static const struct __initconst u300_gpio_confdata
bs335_gpio_config[BS335_GPIO_NUM_PORTS][U300_GPIO_PINS_PER_PORT] = {
	/* Port 0, pins 0-7 */
	{
		U300_FLOATING_INPUT,
		U300_OUTPUT_HIGH,
		U300_FLOATING_INPUT,
		U300_OUTPUT_LOW,
		U300_OUTPUT_LOW,
		U300_OUTPUT_LOW,
		U300_OUTPUT_LOW,
		U300_OUTPUT_LOW,
	},
	/* Port 1, pins 0-7 */
	{
		U300_OUTPUT_LOW,
		U300_OUTPUT_LOW,
		U300_OUTPUT_LOW,
		U300_PULL_UP_INPUT,
		U300_FLOATING_INPUT,
		U300_OUTPUT_HIGH,
		U300_OUTPUT_LOW,
		U300_OUTPUT_LOW,
	},
	/* Port 2, pins 0-7 */
	{
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_OUTPUT_LOW,
		U300_PULL_UP_INPUT,
		U300_OUTPUT_LOW,
		U300_PULL_UP_INPUT,
	},
	/* Port 3, pins 0-7 */
	{
		U300_PULL_UP_INPUT,
		U300_OUTPUT_LOW,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
	},
	/* Port 4, pins 0-7 */
	{
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
	},
	/* Port 5, pins 0-7 */
	{
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
	},
	/* Port 6, pind 0-7 */
	{
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
		U300_FLOATING_INPUT,
	}
};

/**
 * to_u300_gpio() - get the pointer to u300_gpio
 * @chip: the gpio chip member of the structure u300_gpio
 */
static inline struct u300_gpio *to_u300_gpio(struct gpio_chip *chip)
{
	return container_of(chip, struct u300_gpio, chip);
}

static int u300_gpio_request(struct gpio_chip *chip, unsigned offset)
{
	/*
	 * Map back to global GPIO space and request muxing, the direction
	 * parameter does not matter for this controller.
	 */
	int gpio = chip->base + offset;

	return pinctrl_request_gpio(gpio);
}

static void u300_gpio_free(struct gpio_chip *chip, unsigned offset)
{
	int gpio = chip->base + offset;

	pinctrl_free_gpio(gpio);
}

static int u300_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct u300_gpio *gpio = to_u300_gpio(chip);

	return readl(U300_PIN_REG(offset, dir)) & U300_PIN_BIT(offset);
}

static void u300_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct u300_gpio *gpio = to_u300_gpio(chip);
	unsigned long flags;
	u32 val;

	local_irq_save(flags);

	val = readl(U300_PIN_REG(offset, dor));
	if (value)
		writel(val | U300_PIN_BIT(offset), U300_PIN_REG(offset, dor));
	else
		writel(val & ~U300_PIN_BIT(offset), U300_PIN_REG(offset, dor));

	local_irq_restore(flags);
}

static int u300_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
	struct u300_gpio *gpio = to_u300_gpio(chip);
	unsigned long flags;
	u32 val;

	local_irq_save(flags);
	val = readl(U300_PIN_REG(offset, pcr));
	/* Mask out this pin, note 2 bits per setting */
	val &= ~(U300_GPIO_PXPCR_PIN_MODE_MASK << ((offset & 0x07) << 1));
	writel(val, U300_PIN_REG(offset, pcr));
	local_irq_restore(flags);
	return 0;
}

static int u300_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
				      int value)
{
	struct u300_gpio *gpio = to_u300_gpio(chip);
	unsigned long flags;
	u32 oldmode;
	u32 val;

	local_irq_save(flags);
	val = readl(U300_PIN_REG(offset, pcr));
	/*
	 * Drive mode must be set by the special mode set function, set
	 * push/pull mode by default if no mode has been selected.
	 */
	oldmode = val & (U300_GPIO_PXPCR_PIN_MODE_MASK <<
			 ((offset & 0x07) << 1));
	/* mode = 0 means input, else some mode is already set */
	if (oldmode == 0) {
		val &= ~(U300_GPIO_PXPCR_PIN_MODE_MASK <<
			 ((offset & 0x07) << 1));
		val |= (U300_GPIO_PXPCR_PIN_MODE_OUTPUT_PUSH_PULL
			<< ((offset & 0x07) << 1));
		writel(val, U300_PIN_REG(offset, pcr));
	}
	u300_gpio_set(chip, offset, value);
	local_irq_restore(flags);
	return 0;
}

static int u300_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
	struct u300_gpio *gpio = to_u300_gpio(chip);
	int portno = offset >> 3;
	struct u300_gpio_port *port = NULL;
	struct list_head *p;
	int retirq;

	list_for_each(p, &gpio->port_list) {
		port = list_entry(p, struct u300_gpio_port, node);
		if (port->number == portno)
			break;
	}
	if (port == NULL) {
		dev_err(gpio->dev, "could not locate port for GPIO %d IRQ\n",
			offset);
		return -EINVAL;
	}

	/*
	 * The local hwirqs on the port are the lower three bits, there
	 * are exactly 8 IRQs per port since they are 8-bit
	 */
	retirq = irq_find_mapping(port->domain, (offset & 0x7));

	dev_dbg(gpio->dev, "request IRQ for GPIO %d, return %d from port %d\n",
		offset, retirq, port->number);
	return retirq;
}

/* Returning -EINVAL means "supported but not available" */
int u300_gpio_config_get(struct gpio_chip *chip,
			 unsigned offset,
			 unsigned long *config)
{
	struct u300_gpio *gpio = to_u300_gpio(chip);
	enum pin_config_param param = (enum pin_config_param) *config;
	bool biasmode;
	u32 drmode;

	/* One bit per pin, clamp to bool range */
	biasmode = !!(readl(U300_PIN_REG(offset, per)) & U300_PIN_BIT(offset));

	/* Mask out the two bits for this pin and shift to bits 0,1 */
	drmode = readl(U300_PIN_REG(offset, pcr));
	drmode &= (U300_GPIO_PXPCR_PIN_MODE_MASK << ((offset & 0x07) << 1));
	drmode >>= ((offset & 0x07) << 1);

	switch(param) {
	case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
		*config = 0;
		if (biasmode)
			return 0;
		else
			return -EINVAL;
		break;
	case PIN_CONFIG_BIAS_PULL_UP:
		*config = 0;
		if (!biasmode)
			return 0;
		else
			return -EINVAL;
		break;
	case PIN_CONFIG_DRIVE_PUSH_PULL:
		*config = 0;
		if (drmode == U300_GPIO_PXPCR_PIN_MODE_OUTPUT_PUSH_PULL)
			return 0;
		else
			return -EINVAL;
		break;
	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
		*config = 0;
		if (drmode == U300_GPIO_PXPCR_PIN_MODE_OUTPUT_OPEN_DRAIN)
			return 0;
		else
			return -EINVAL;
		break;
	case PIN_CONFIG_DRIVE_OPEN_SOURCE:
		*config = 0;
		if (drmode == U300_GPIO_PXPCR_PIN_MODE_OUTPUT_OPEN_SOURCE)
			return 0;
		else
			return -EINVAL;
		break;
	default:
		break;
	}
	return -ENOTSUPP;
}

int u300_gpio_config_set(struct gpio_chip *chip, unsigned offset,
			 enum pin_config_param param)
{
	struct u300_gpio *gpio = to_u300_gpio(chip);
	unsigned long flags;
	u32 val;

	local_irq_save(flags);
	switch (param) {
	case PIN_CONFIG_BIAS_DISABLE:
	case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
		val = readl(U300_PIN_REG(offset, per));
		writel(val | U300_PIN_BIT(offset), U300_PIN_REG(offset, per));
		break;
	case PIN_CONFIG_BIAS_PULL_UP:
		val = readl(U300_PIN_REG(offset, per));
		writel(val & ~U300_PIN_BIT(offset), U300_PIN_REG(offset, per));
		break;
	case PIN_CONFIG_DRIVE_PUSH_PULL:
		val = readl(U300_PIN_REG(offset, pcr));
		val &= ~(U300_GPIO_PXPCR_PIN_MODE_MASK
			 << ((offset & 0x07) << 1));
		val |= (U300_GPIO_PXPCR_PIN_MODE_OUTPUT_PUSH_PULL
			<< ((offset & 0x07) << 1));
		writel(val, U300_PIN_REG(offset, pcr));
		break;
	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
		val = readl(U300_PIN_REG(offset, pcr));
		val &= ~(U300_GPIO_PXPCR_PIN_MODE_MASK
			 << ((offset & 0x07) << 1));
		val |= (U300_GPIO_PXPCR_PIN_MODE_OUTPUT_OPEN_DRAIN
			<< ((offset & 0x07) << 1));
		writel(val, U300_PIN_REG(offset, pcr));
		break;
	case PIN_CONFIG_DRIVE_OPEN_SOURCE:
		val = readl(U300_PIN_REG(offset, pcr));
		val &= ~(U300_GPIO_PXPCR_PIN_MODE_MASK
			 << ((offset & 0x07) << 1));
		val |= (U300_GPIO_PXPCR_PIN_MODE_OUTPUT_OPEN_SOURCE
			<< ((offset & 0x07) << 1));
		writel(val, U300_PIN_REG(offset, pcr));
		break;
	default:
		local_irq_restore(flags);
		dev_err(gpio->dev, "illegal configuration requested\n");
		return -EINVAL;
	}
	local_irq_restore(flags);
	return 0;
}

static struct gpio_chip u300_gpio_chip = {
	.label			= "u300-gpio-chip",
	.owner			= THIS_MODULE,
	.request		= u300_gpio_request,
	.free			= u300_gpio_free,
	.get			= u300_gpio_get,
	.set			= u300_gpio_set,
	.direction_input	= u300_gpio_direction_input,
	.direction_output	= u300_gpio_direction_output,
	.to_irq			= u300_gpio_to_irq,
};

static void u300_toggle_trigger(struct u300_gpio *gpio, unsigned offset)
{
	u32 val;

	val = readl(U300_PIN_REG(offset, icr));
	/* Set mode depending on state */
	if (u300_gpio_get(&gpio->chip, offset)) {
		/* High now, let's trigger on falling edge next then */
		writel(val & ~U300_PIN_BIT(offset), U300_PIN_REG(offset, icr));
		dev_dbg(gpio->dev, "next IRQ on falling edge on pin %d\n",
			offset);
	} else {
		/* Low now, let's trigger on rising edge next then */
		writel(val | U300_PIN_BIT(offset), U300_PIN_REG(offset, icr));
		dev_dbg(gpio->dev, "next IRQ on rising edge on pin %d\n",
			offset);
	}
}

static int u300_gpio_irq_type(struct irq_data *d, unsigned trigger)
{
	struct u300_gpio_port *port = irq_data_get_irq_chip_data(d);
	struct u300_gpio *gpio = port->gpio;
	int offset = (port->number << 3) + d->hwirq;
	u32 val;

	if ((trigger & IRQF_TRIGGER_RISING) &&
	    (trigger & IRQF_TRIGGER_FALLING)) {
		/*
		 * The GPIO block can only trigger on falling OR rising edges,
		 * not both. So we need to toggle the mode whenever the pin
		 * goes from one state to the other with a special state flag
		 */
		dev_dbg(gpio->dev,
			"trigger on both rising and falling edge on pin %d\n",
			offset);
		port->toggle_edge_mode |= U300_PIN_BIT(offset);
		u300_toggle_trigger(gpio, offset);
	} else if (trigger & IRQF_TRIGGER_RISING) {
		dev_dbg(gpio->dev, "trigger on rising edge on pin %d\n",
			offset);
		val = readl(U300_PIN_REG(offset, icr));
		writel(val | U300_PIN_BIT(offset), U300_PIN_REG(offset, icr));
		port->toggle_edge_mode &= ~U300_PIN_BIT(offset);
	} else if (trigger & IRQF_TRIGGER_FALLING) {
		dev_dbg(gpio->dev, "trigger on falling edge on pin %d\n",
			offset);
		val = readl(U300_PIN_REG(offset, icr));
		writel(val & ~U300_PIN_BIT(offset), U300_PIN_REG(offset, icr));
		port->toggle_edge_mode &= ~U300_PIN_BIT(offset);
	}

	return 0;
}

static void u300_gpio_irq_enable(struct irq_data *d)
{
	struct u300_gpio_port *port = irq_data_get_irq_chip_data(d);
	struct u300_gpio *gpio = port->gpio;
	int offset = (port->number << 3) + d->hwirq;
	u32 val;
	unsigned long flags;

	dev_dbg(gpio->dev, "enable IRQ for hwirq %lu on port %s, offset %d\n",
		 d->hwirq, port->name, offset);
	local_irq_save(flags);
	val = readl(U300_PIN_REG(offset, ien));
	writel(val | U300_PIN_BIT(offset), U300_PIN_REG(offset, ien));
	local_irq_restore(flags);
}

static void u300_gpio_irq_disable(struct irq_data *d)
{
	struct u300_gpio_port *port = irq_data_get_irq_chip_data(d);
	struct u300_gpio *gpio = port->gpio;
	int offset = (port->number << 3) + d->hwirq;
	u32 val;
	unsigned long flags;

	local_irq_save(flags);
	val = readl(U300_PIN_REG(offset, ien));
	writel(val & ~U300_PIN_BIT(offset), U300_PIN_REG(offset, ien));
	local_irq_restore(flags);
}

static struct irq_chip u300_gpio_irqchip = {
	.name			= "u300-gpio-irqchip",
	.irq_enable		= u300_gpio_irq_enable,
	.irq_disable		= u300_gpio_irq_disable,
	.irq_set_type		= u300_gpio_irq_type,

};

static void u300_gpio_irq_handler(unsigned irq, struct irq_desc *desc)
{
	struct u300_gpio_port *port = irq_get_handler_data(irq);
	struct u300_gpio *gpio = port->gpio;
	int pinoffset = port->number << 3; /* get the right stride */
	unsigned long val;

	desc->irq_data.chip->irq_ack(&desc->irq_data);
	/* Read event register */
	val = readl(U300_PIN_REG(pinoffset, iev));
	/* Mask relevant bits */
	val &= 0xFFU; /* 8 bits per port */
	/* ACK IRQ (clear event) */
	writel(val, U300_PIN_REG(pinoffset, iev));

	/* Call IRQ handler */
	if (val != 0) {
		int irqoffset;

		for_each_set_bit(irqoffset, &val, U300_GPIO_PINS_PER_PORT) {
			int pin_irq = irq_find_mapping(port->domain, irqoffset);
			int offset = pinoffset + irqoffset;

			dev_dbg(gpio->dev, "GPIO IRQ %d on pin %d\n",
				pin_irq, offset);
			generic_handle_irq(pin_irq);
			/*
			 * Triggering IRQ on both rising and falling edge
			 * needs mockery
			 */
			if (port->toggle_edge_mode & U300_PIN_BIT(offset))
				u300_toggle_trigger(gpio, offset);
		}
	}

	desc->irq_data.chip->irq_unmask(&desc->irq_data);
}

static void __init u300_gpio_init_pin(struct u300_gpio *gpio,
				      int offset,
				      const struct u300_gpio_confdata *conf)
{
	/* Set mode: input or output */
	if (conf->output) {
		u300_gpio_direction_output(&gpio->chip, offset, conf->outval);

		/* Deactivate bias mode for output */
		u300_gpio_config_set(&gpio->chip, offset,
				     PIN_CONFIG_BIAS_HIGH_IMPEDANCE);

		/* Set drive mode for output */
		u300_gpio_config_set(&gpio->chip, offset,
				     PIN_CONFIG_DRIVE_PUSH_PULL);

		dev_dbg(gpio->dev, "set up pin %d as output, value: %d\n",
			offset, conf->outval);
	} else {
		u300_gpio_direction_input(&gpio->chip, offset);

		/* Always set output low on input pins */
		u300_gpio_set(&gpio->chip, offset, 0);

		/* Set bias mode for input */
		u300_gpio_config_set(&gpio->chip, offset, conf->bias_mode);

		dev_dbg(gpio->dev, "set up pin %d as input, bias: %04x\n",
			offset, conf->bias_mode);
	}
}

static void __init u300_gpio_init_coh901571(struct u300_gpio *gpio,
				     struct u300_gpio_platform *plat)
{
	int i, j;

	/* Write default config and values to all pins */
	for (i = 0; i < plat->ports; i++) {
		for (j = 0; j < 8; j++) {
			const struct u300_gpio_confdata *conf;
			int offset = (i*8) + j;

			conf = &bs335_gpio_config[i][j];
			u300_gpio_init_pin(gpio, offset, conf);
		}
	}
}

static inline void u300_gpio_free_ports(struct u300_gpio *gpio)
{
	struct u300_gpio_port *port;
	struct list_head *p, *n;

	list_for_each_safe(p, n, &gpio->port_list) {
		port = list_entry(p, struct u300_gpio_port, node);
		list_del(&port->node);
		if (port->domain)
			irq_domain_remove(port->domain);
		kfree(port);
	}
}

static int __init u300_gpio_probe(struct platform_device *pdev)
{
	struct u300_gpio_platform *plat = dev_get_platdata(&pdev->dev);
	struct u300_gpio *gpio;
	int err = 0;
	int portno;
	u32 val;
	u32 ifr;
	int i;

	gpio = kzalloc(sizeof(struct u300_gpio), GFP_KERNEL);
	if (gpio == NULL) {
		dev_err(&pdev->dev, "failed to allocate memory\n");
		return -ENOMEM;
	}

	gpio->chip = u300_gpio_chip;
	gpio->chip.ngpio = plat->ports * U300_GPIO_PINS_PER_PORT;
	gpio->chip.dev = &pdev->dev;
	gpio->chip.base = plat->gpio_base;
	gpio->dev = &pdev->dev;

	/* Get GPIO clock */
	gpio->clk = clk_get(gpio->dev, NULL);
	if (IS_ERR(gpio->clk)) {
		err = PTR_ERR(gpio->clk);
		dev_err(gpio->dev, "could not get GPIO clock\n");
		goto err_no_clk;
	}
	err = clk_prepare_enable(gpio->clk);
	if (err) {
		dev_err(gpio->dev, "could not enable GPIO clock\n");
		goto err_no_clk_enable;
	}

	gpio->memres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!gpio->memres) {
		dev_err(gpio->dev, "could not get GPIO memory resource\n");
		err = -ENODEV;
		goto err_no_resource;
	}

	if (!request_mem_region(gpio->memres->start,
				resource_size(gpio->memres),
				"GPIO Controller")) {
		err = -ENODEV;
		goto err_no_ioregion;
	}

	gpio->base = ioremap(gpio->memres->start, resource_size(gpio->memres));
	if (!gpio->base) {
		err = -ENOMEM;
		goto err_no_ioremap;
	}

	dev_info(gpio->dev,
		 "initializing GPIO Controller COH 901 571/3\n");
	gpio->stride = U300_GPIO_PORT_STRIDE;
	gpio->pcr = U300_GPIO_PXPCR;
	gpio->dor = U300_GPIO_PXPDOR;
	gpio->dir = U300_GPIO_PXPDIR;
	gpio->per = U300_GPIO_PXPER;
	gpio->icr = U300_GPIO_PXICR;
	gpio->ien = U300_GPIO_PXIEN;
	gpio->iev = U300_GPIO_PXIEV;
	ifr = U300_GPIO_PXIFR;

	val = readl(gpio->base + U300_GPIO_CR);
	dev_info(gpio->dev, "COH901571/3 block version: %d, " \
		 "number of cores: %d totalling %d pins\n",
		 ((val & 0x000001FC) >> 2),
		 ((val & 0x0000FE00) >> 9),
		 ((val & 0x0000FE00) >> 9) * 8);
	writel(U300_GPIO_CR_BLOCK_CLKRQ_ENABLE,
	       gpio->base + U300_GPIO_CR);
	u300_gpio_init_coh901571(gpio, plat);

	/* Add each port with its IRQ separately */
	INIT_LIST_HEAD(&gpio->port_list);
	for (portno = 0 ; portno < plat->ports; portno++) {
		struct u300_gpio_port *port =
			kmalloc(sizeof(struct u300_gpio_port), GFP_KERNEL);

		if (!port) {
			dev_err(gpio->dev, "out of memory\n");
			err = -ENOMEM;
			goto err_no_port;
		}

		snprintf(port->name, 8, "gpio%d", portno);
		port->number = portno;
		port->gpio = gpio;

		port->irq = platform_get_irq_byname(pdev,
						    port->name);

		dev_dbg(gpio->dev, "register IRQ %d for port %s\n", port->irq,
			port->name);

		port->domain = irq_domain_add_linear(pdev->dev.of_node,
						     U300_GPIO_PINS_PER_PORT,
						     &irq_domain_simple_ops,
						     port);
		if (!port->domain)
			goto err_no_domain;

		irq_set_chained_handler(port->irq, u300_gpio_irq_handler);
		irq_set_handler_data(port->irq, port);

		/* For each GPIO pin set the unique IRQ handler */
		for (i = 0; i < U300_GPIO_PINS_PER_PORT; i++) {
			int irqno = irq_create_mapping(port->domain, i);

			dev_dbg(gpio->dev, "GPIO%d on port %s gets IRQ %d\n",
				gpio->chip.base + (port->number << 3) + i,
				port->name, irqno);
			irq_set_chip_and_handler(irqno, &u300_gpio_irqchip,
						 handle_simple_irq);
			set_irq_flags(irqno, IRQF_VALID);
			irq_set_chip_data(irqno, port);
		}

		/* Turns off irq force (test register) for this port */
		writel(0x0, gpio->base + portno * gpio->stride + ifr);

		list_add_tail(&port->node, &gpio->port_list);
	}
	dev_dbg(gpio->dev, "initialized %d GPIO ports\n", portno);

	err = gpiochip_add(&gpio->chip);
	if (err) {
		dev_err(gpio->dev, "unable to add gpiochip: %d\n", err);
		goto err_no_chip;
	}

	/* Spawn pin controller device as child of the GPIO, pass gpio chip */
	plat->pinctrl_device->dev.platform_data = &gpio->chip;
	err = platform_device_register(plat->pinctrl_device);
	if (err)
		goto err_no_pinctrl;

	platform_set_drvdata(pdev, gpio);

	return 0;

err_no_pinctrl:
	err = gpiochip_remove(&gpio->chip);
err_no_chip:
err_no_domain:
err_no_port:
	u300_gpio_free_ports(gpio);
	iounmap(gpio->base);
err_no_ioremap:
	release_mem_region(gpio->memres->start, resource_size(gpio->memres));
err_no_ioregion:
err_no_resource:
	clk_disable_unprepare(gpio->clk);
err_no_clk_enable:
	clk_put(gpio->clk);
err_no_clk:
	kfree(gpio);
	dev_info(&pdev->dev, "module ERROR:%d\n", err);
	return err;
}

static int __exit u300_gpio_remove(struct platform_device *pdev)
{
	struct u300_gpio *gpio = platform_get_drvdata(pdev);
	int err;

	/* Turn off the GPIO block */
	writel(0x00000000U, gpio->base + U300_GPIO_CR);

	err = gpiochip_remove(&gpio->chip);
	if (err < 0) {
		dev_err(gpio->dev, "unable to remove gpiochip: %d\n", err);
		return err;
	}
	u300_gpio_free_ports(gpio);
	iounmap(gpio->base);
	release_mem_region(gpio->memres->start,
			   resource_size(gpio->memres));
	clk_disable_unprepare(gpio->clk);
	clk_put(gpio->clk);
	platform_set_drvdata(pdev, NULL);
	kfree(gpio);
	return 0;
}

static struct platform_driver u300_gpio_driver = {
	.driver		= {
		.name	= "u300-gpio",
	},
	.remove		= __exit_p(u300_gpio_remove),
};

static int __init u300_gpio_init(void)
{
	return platform_driver_probe(&u300_gpio_driver, u300_gpio_probe);
}

static void __exit u300_gpio_exit(void)
{
	platform_driver_unregister(&u300_gpio_driver);
}

arch_initcall(u300_gpio_init);
module_exit(u300_gpio_exit);

MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
MODULE_DESCRIPTION("ST-Ericsson AB COH 901 335/COH 901 571/3 GPIO driver");
MODULE_LICENSE("GPL");