summaryrefslogtreecommitdiffstats
path: root/arch/arm/plat-orion/gpio.c
blob: 078894bc3b9a2f59e59b941d7d1259749a8ff2a8 (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
/*
 * arch/arm/plat-orion/gpio.c
 *
 * Marvell Orion SoC GPIO handling.
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/gpio.h>

/*
 * GPIO unit register offsets.
 */
#define GPIO_OUT_OFF		0x0000
#define GPIO_IO_CONF_OFF	0x0004
#define GPIO_BLINK_EN_OFF	0x0008
#define GPIO_IN_POL_OFF		0x000c
#define GPIO_DATA_IN_OFF	0x0010
#define GPIO_EDGE_CAUSE_OFF	0x0014
#define GPIO_EDGE_MASK_OFF	0x0018
#define GPIO_LEVEL_MASK_OFF	0x001c

struct orion_gpio_chip {
	struct gpio_chip	chip;
	spinlock_t		lock;
	void __iomem		*base;
	unsigned long		valid_input;
	unsigned long		valid_output;
	int			mask_offset;
	int			secondary_irq_base;
};

static void __iomem *GPIO_OUT(struct orion_gpio_chip *ochip)
{
	return ochip->base + GPIO_OUT_OFF;
}

static void __iomem *GPIO_IO_CONF(struct orion_gpio_chip *ochip)
{
	return ochip->base + GPIO_IO_CONF_OFF;
}

static void __iomem *GPIO_BLINK_EN(struct orion_gpio_chip *ochip)
{
	return ochip->base + GPIO_BLINK_EN_OFF;
}

static void __iomem *GPIO_IN_POL(struct orion_gpio_chip *ochip)
{
	return ochip->base + GPIO_IN_POL_OFF;
}

static void __iomem *GPIO_DATA_IN(struct orion_gpio_chip *ochip)
{
	return ochip->base + GPIO_DATA_IN_OFF;
}

static void __iomem *GPIO_EDGE_CAUSE(struct orion_gpio_chip *ochip)
{
	return ochip->base + GPIO_EDGE_CAUSE_OFF;
}

static void __iomem *GPIO_EDGE_MASK(struct orion_gpio_chip *ochip)
{
	return ochip->base + ochip->mask_offset + GPIO_EDGE_MASK_OFF;
}

static void __iomem *GPIO_LEVEL_MASK(struct orion_gpio_chip *ochip)
{
	return ochip->base + ochip->mask_offset + GPIO_LEVEL_MASK_OFF;
}


static struct orion_gpio_chip orion_gpio_chips[2];
static int orion_gpio_chip_count;

static inline void
__set_direction(struct orion_gpio_chip *ochip, unsigned pin, int input)
{
	u32 u;

	u = readl(GPIO_IO_CONF(ochip));
	if (input)
		u |= 1 << pin;
	else
		u &= ~(1 << pin);
	writel(u, GPIO_IO_CONF(ochip));
}

static void __set_level(struct orion_gpio_chip *ochip, unsigned pin, int high)
{
	u32 u;

	u = readl(GPIO_OUT(ochip));
	if (high)
		u |= 1 << pin;
	else
		u &= ~(1 << pin);
	writel(u, GPIO_OUT(ochip));
}

static inline void
__set_blinking(struct orion_gpio_chip *ochip, unsigned pin, int blink)
{
	u32 u;

	u = readl(GPIO_BLINK_EN(ochip));
	if (blink)
		u |= 1 << pin;
	else
		u &= ~(1 << pin);
	writel(u, GPIO_BLINK_EN(ochip));
}

static inline int
orion_gpio_is_valid(struct orion_gpio_chip *ochip, unsigned pin, int mode)
{
	if (pin >= ochip->chip.ngpio)
		goto err_out;

	if ((mode & GPIO_INPUT_OK) && !test_bit(pin, &ochip->valid_input))
		goto err_out;

	if ((mode & GPIO_OUTPUT_OK) && !test_bit(pin, &ochip->valid_output))
		goto err_out;

	return 1;

err_out:
	pr_debug("%s: invalid GPIO %d\n", __func__, pin);
	return false;
}

/*
 * GENERIC_GPIO primitives.
 */
static int orion_gpio_request(struct gpio_chip *chip, unsigned pin)
{
	struct orion_gpio_chip *ochip =
		container_of(chip, struct orion_gpio_chip, chip);

	if (orion_gpio_is_valid(ochip, pin, GPIO_INPUT_OK) ||
	    orion_gpio_is_valid(ochip, pin, GPIO_OUTPUT_OK))
		return 0;

	return -EINVAL;
}

static int orion_gpio_direction_input(struct gpio_chip *chip, unsigned pin)
{
	struct orion_gpio_chip *ochip =
		container_of(chip, struct orion_gpio_chip, chip);
	unsigned long flags;

	if (!orion_gpio_is_valid(ochip, pin, GPIO_INPUT_OK))
		return -EINVAL;

	spin_lock_irqsave(&ochip->lock, flags);
	__set_direction(ochip, pin, 1);
	spin_unlock_irqrestore(&ochip->lock, flags);

	return 0;
}

static int orion_gpio_get(struct gpio_chip *chip, unsigned pin)
{
	struct orion_gpio_chip *ochip =
		container_of(chip, struct orion_gpio_chip, chip);
	int val;

	if (readl(GPIO_IO_CONF(ochip)) & (1 << pin)) {
		val = readl(GPIO_DATA_IN(ochip)) ^ readl(GPIO_IN_POL(ochip));
	} else {
		val = readl(GPIO_OUT(ochip));
	}

	return (val >> pin) & 1;
}

static int
orion_gpio_direction_output(struct gpio_chip *chip, unsigned pin, int value)
{
	struct orion_gpio_chip *ochip =
		container_of(chip, struct orion_gpio_chip, chip);
	unsigned long flags;

	if (!orion_gpio_is_valid(ochip, pin, GPIO_OUTPUT_OK))
		return -EINVAL;

	spin_lock_irqsave(&ochip->lock, flags);
	__set_blinking(ochip, pin, 0);
	__set_level(ochip, pin, value);
	__set_direction(ochip, pin, 0);
	spin_unlock_irqrestore(&ochip->lock, flags);

	return 0;
}

static void orion_gpio_set(struct gpio_chip *chip, unsigned pin, int value)
{
	struct orion_gpio_chip *ochip =
		container_of(chip, struct orion_gpio_chip, chip);
	unsigned long flags;

	spin_lock_irqsave(&ochip->lock, flags);
	__set_level(ochip, pin, value);
	spin_unlock_irqrestore(&ochip->lock, flags);
}

static int orion_gpio_to_irq(struct gpio_chip *chip, unsigned pin)
{
	struct orion_gpio_chip *ochip =
		container_of(chip, struct orion_gpio_chip, chip);

	return ochip->secondary_irq_base + pin;
}


/*
 * Orion-specific GPIO API extensions.
 */
static struct orion_gpio_chip *orion_gpio_chip_find(int pin)
{
	int i;

	for (i = 0; i < orion_gpio_chip_count; i++) {
		struct orion_gpio_chip *ochip = orion_gpio_chips + i;
		struct gpio_chip *chip = &ochip->chip;

		if (pin >= chip->base && pin < chip->base + chip->ngpio)
			return ochip;
	}

	return NULL;
}

void __init orion_gpio_set_unused(unsigned pin)
{
	struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);

	if (ochip == NULL)
		return;

	pin -= ochip->chip.base;

	/* Configure as output, drive low. */
	__set_level(ochip, pin, 0);
	__set_direction(ochip, pin, 0);
}

void __init orion_gpio_set_valid(unsigned pin, int mode)
{
	struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);

	if (ochip == NULL)
		return;

	pin -= ochip->chip.base;

	if (mode == 1)
		mode = GPIO_INPUT_OK | GPIO_OUTPUT_OK;

	if (mode & GPIO_INPUT_OK)
		__set_bit(pin, &ochip->valid_input);
	else
		__clear_bit(pin, &ochip->valid_input);

	if (mode & GPIO_OUTPUT_OK)
		__set_bit(pin, &ochip->valid_output);
	else
		__clear_bit(pin, &ochip->valid_output);
}

void orion_gpio_set_blink(unsigned pin, int blink)
{
	struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
	unsigned long flags;

	if (ochip == NULL)
		return;

	spin_lock_irqsave(&ochip->lock, flags);
	__set_level(ochip, pin, 0);
	__set_blinking(ochip, pin, blink);
	spin_unlock_irqrestore(&ochip->lock, flags);
}
EXPORT_SYMBOL(orion_gpio_set_blink);


/*****************************************************************************
 * Orion GPIO IRQ
 *
 * GPIO_IN_POL register controls whether GPIO_DATA_IN will hold the same
 * value of the line or the opposite value.
 *
 * Level IRQ handlers: DATA_IN is used directly as cause register.
 *                     Interrupt are masked by LEVEL_MASK registers.
 * Edge IRQ handlers:  Change in DATA_IN are latched in EDGE_CAUSE.
 *                     Interrupt are masked by EDGE_MASK registers.
 * Both-edge handlers: Similar to regular Edge handlers, but also swaps
 *                     the polarity to catch the next line transaction.
 *                     This is a race condition that might not perfectly
 *                     work on some use cases.
 *
 * Every eight GPIO lines are grouped (OR'ed) before going up to main
 * cause register.
 *
 *                    EDGE  cause    mask
 *        data-in   /--------| |-----| |----\
 *     -----| |-----                         ---- to main cause reg
 *           X      \----------------| |----/
 *        polarity    LEVEL          mask
 *
 ****************************************************************************/
static void gpio_irq_ack(struct irq_data *d)
{
	struct orion_gpio_chip *ochip = irq_data_get_irq_chip_data(d);
	int type;

	type = irq_desc[d->irq].status & IRQ_TYPE_SENSE_MASK;
	if (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)) {
		int pin = d->irq - ochip->secondary_irq_base;

		writel(~(1 << pin), GPIO_EDGE_CAUSE(ochip));
	}
}

static void gpio_irq_mask(struct irq_data *d)
{
	struct orion_gpio_chip *ochip = irq_data_get_irq_chip_data(d);
	int type;
	void __iomem *reg;
	int pin;

	type = irq_desc[d->irq].status & IRQ_TYPE_SENSE_MASK;
	if (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING))
		reg = GPIO_EDGE_MASK(ochip);
	else
		reg = GPIO_LEVEL_MASK(ochip);

	pin = d->irq - ochip->secondary_irq_base;

	writel(readl(reg) & ~(1 << pin), reg);
}

static void gpio_irq_unmask(struct irq_data *d)
{
	struct orion_gpio_chip *ochip = irq_data_get_irq_chip_data(d);
	int type;
	void __iomem *reg;
	int pin;

	type = irq_desc[d->irq].status & IRQ_TYPE_SENSE_MASK;
	if (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING))
		reg = GPIO_EDGE_MASK(ochip);
	else
		reg = GPIO_LEVEL_MASK(ochip);

	pin = d->irq - ochip->secondary_irq_base;

	writel(readl(reg) | (1 << pin), reg);
}

static int gpio_irq_set_type(struct irq_data *d, u32 type)
{
	struct orion_gpio_chip *ochip = irq_data_get_irq_chip_data(d);
	int pin;
	u32 u;

	pin = d->irq - ochip->secondary_irq_base;

	u = readl(GPIO_IO_CONF(ochip)) & (1 << pin);
	if (!u) {
		printk(KERN_ERR "orion gpio_irq_set_type failed "
				"(irq %d, pin %d).\n", d->irq, pin);
		return -EINVAL;
	}

	/*
	 * Set edge/level type.
	 */
	if (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)) {
		set_irq_handler(d->irq, handle_edge_irq);
	} else if (type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
		set_irq_handler(d->irq, handle_level_irq);
	} else {
		printk(KERN_ERR "failed to set irq=%d (type=%d)\n",
		       d->irq, type);
		return -EINVAL;
	}

	/*
	 * Configure interrupt polarity.
	 */
	if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH) {
		u = readl(GPIO_IN_POL(ochip));
		u &= ~(1 << pin);
		writel(u, GPIO_IN_POL(ochip));
	} else if (type == IRQ_TYPE_EDGE_FALLING || type == IRQ_TYPE_LEVEL_LOW) {
		u = readl(GPIO_IN_POL(ochip));
		u |= 1 << pin;
		writel(u, GPIO_IN_POL(ochip));
	} else if (type == IRQ_TYPE_EDGE_BOTH) {
		u32 v;

		v = readl(GPIO_IN_POL(ochip)) ^ readl(GPIO_DATA_IN(ochip));

		/*
		 * set initial polarity based on current input level
		 */
		u = readl(GPIO_IN_POL(ochip));
		if (v & (1 << pin))
			u |= 1 << pin;		/* falling */
		else
			u &= ~(1 << pin);	/* rising */
		writel(u, GPIO_IN_POL(ochip));
	}

	return 0;
}

struct irq_chip orion_gpio_irq_chip = {
	.name		= "orion_gpio_irq",
	.irq_ack	= gpio_irq_ack,
	.irq_mask	= gpio_irq_mask,
	.irq_unmask	= gpio_irq_unmask,
	.irq_set_type	= gpio_irq_set_type,
};

void __init orion_gpio_init(int gpio_base, int ngpio,
			    u32 base, int mask_offset, int secondary_irq_base)
{
	struct orion_gpio_chip *ochip;
	int i;

	if (orion_gpio_chip_count == ARRAY_SIZE(orion_gpio_chips))
		return;

	ochip = orion_gpio_chips + orion_gpio_chip_count;
	ochip->chip.label = "orion_gpio";
	ochip->chip.request = orion_gpio_request;
	ochip->chip.direction_input = orion_gpio_direction_input;
	ochip->chip.get = orion_gpio_get;
	ochip->chip.direction_output = orion_gpio_direction_output;
	ochip->chip.set = orion_gpio_set;
	ochip->chip.to_irq = orion_gpio_to_irq;
	ochip->chip.base = gpio_base;
	ochip->chip.ngpio = ngpio;
	ochip->chip.can_sleep = 0;
	spin_lock_init(&ochip->lock);
	ochip->base = (void __iomem *)base;
	ochip->valid_input = 0;
	ochip->valid_output = 0;
	ochip->mask_offset = mask_offset;
	ochip->secondary_irq_base = secondary_irq_base;

	gpiochip_add(&ochip->chip);

	orion_gpio_chip_count++;

	/*
	 * Mask and clear GPIO interrupts.
	 */
	writel(0, GPIO_EDGE_CAUSE(ochip));
	writel(0, GPIO_EDGE_MASK(ochip));
	writel(0, GPIO_LEVEL_MASK(ochip));

	for (i = 0; i < ngpio; i++) {
		unsigned int irq = secondary_irq_base + i;

		set_irq_chip(irq, &orion_gpio_irq_chip);
		set_irq_handler(irq, handle_level_irq);
		set_irq_chip_data(irq, ochip);
		irq_desc[irq].status |= IRQ_LEVEL;
		set_irq_flags(irq, IRQF_VALID);
	}
}

void orion_gpio_irq_handler(int pinoff)
{
	struct orion_gpio_chip *ochip;
	u32 cause;
	int i;

	ochip = orion_gpio_chip_find(pinoff);
	if (ochip == NULL)
		return;

	cause = readl(GPIO_DATA_IN(ochip)) & readl(GPIO_LEVEL_MASK(ochip));
	cause |= readl(GPIO_EDGE_CAUSE(ochip)) & readl(GPIO_EDGE_MASK(ochip));

	for (i = 0; i < ochip->chip.ngpio; i++) {
		int irq;
		struct irq_desc *desc;

		irq = ochip->secondary_irq_base + i;

		if (!(cause & (1 << i)))
			continue;

		desc = irq_desc + irq;
		if ((desc->status & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
			/* Swap polarity (race with GPIO line) */
			u32 polarity;

			polarity = readl(GPIO_IN_POL(ochip));
			polarity ^= 1 << i;
			writel(polarity, GPIO_IN_POL(ochip));
		}

		desc_handle_irq(irq, desc);
	}
}
OpenPOWER on IntegriCloud