xref: /openbmc/linux/drivers/gpio/gpio-aspeed.c (revision 4a3fad70)
1 /*
2  * Copyright 2015 IBM Corp.
3  *
4  * Joel Stanley <joel@jms.id.au>
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #include <asm/div64.h>
13 #include <linux/clk.h>
14 #include <linux/gpio/driver.h>
15 #include <linux/hashtable.h>
16 #include <linux/init.h>
17 #include <linux/io.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/pinctrl/consumer.h>
21 #include <linux/platform_device.h>
22 #include <linux/spinlock.h>
23 #include <linux/string.h>
24 
25 struct aspeed_bank_props {
26 	unsigned int bank;
27 	u32 input;
28 	u32 output;
29 };
30 
31 struct aspeed_gpio_config {
32 	unsigned int nr_gpios;
33 	const struct aspeed_bank_props *props;
34 };
35 
36 /*
37  * @offset_timer: Maps an offset to an @timer_users index, or zero if disabled
38  * @timer_users: Tracks the number of users for each timer
39  *
40  * The @timer_users has four elements but the first element is unused. This is
41  * to simplify accounting and indexing, as a zero value in @offset_timer
42  * represents disabled debouncing for the GPIO. Any other value for an element
43  * of @offset_timer is used as an index into @timer_users. This behaviour of
44  * the zero value aligns with the behaviour of zero built from the timer
45  * configuration registers (i.e. debouncing is disabled).
46  */
47 struct aspeed_gpio {
48 	struct gpio_chip chip;
49 	spinlock_t lock;
50 	void __iomem *base;
51 	int irq;
52 	const struct aspeed_gpio_config *config;
53 
54 	u8 *offset_timer;
55 	unsigned int timer_users[4];
56 	struct clk *clk;
57 };
58 
59 struct aspeed_gpio_bank {
60 	uint16_t	val_regs;
61 	uint16_t	irq_regs;
62 	uint16_t	debounce_regs;
63 	const char	names[4][3];
64 };
65 
66 static const int debounce_timers[4] = { 0x00, 0x50, 0x54, 0x58 };
67 
68 static const struct aspeed_gpio_bank aspeed_gpio_banks[] = {
69 	{
70 		.val_regs = 0x0000,
71 		.irq_regs = 0x0008,
72 		.debounce_regs = 0x0040,
73 		.names = { "A", "B", "C", "D" },
74 	},
75 	{
76 		.val_regs = 0x0020,
77 		.irq_regs = 0x0028,
78 		.debounce_regs = 0x0048,
79 		.names = { "E", "F", "G", "H" },
80 	},
81 	{
82 		.val_regs = 0x0070,
83 		.irq_regs = 0x0098,
84 		.debounce_regs = 0x00b0,
85 		.names = { "I", "J", "K", "L" },
86 	},
87 	{
88 		.val_regs = 0x0078,
89 		.irq_regs = 0x00e8,
90 		.debounce_regs = 0x0100,
91 		.names = { "M", "N", "O", "P" },
92 	},
93 	{
94 		.val_regs = 0x0080,
95 		.irq_regs = 0x0118,
96 		.debounce_regs = 0x0130,
97 		.names = { "Q", "R", "S", "T" },
98 	},
99 	{
100 		.val_regs = 0x0088,
101 		.irq_regs = 0x0148,
102 		.debounce_regs = 0x0160,
103 		.names = { "U", "V", "W", "X" },
104 	},
105 	{
106 		.val_regs = 0x01E0,
107 		.irq_regs = 0x0178,
108 		.debounce_regs = 0x0190,
109 		.names = { "Y", "Z", "AA", "AB" },
110 	},
111 	{
112 		.val_regs = 0x01E8,
113 		.irq_regs = 0x01A8,
114 		.debounce_regs = 0x01c0,
115 		.names = { "AC", "", "", "" },
116 	},
117 };
118 
119 #define GPIO_BANK(x)	((x) >> 5)
120 #define GPIO_OFFSET(x)	((x) & 0x1f)
121 #define GPIO_BIT(x)	BIT(GPIO_OFFSET(x))
122 
123 #define GPIO_DATA	0x00
124 #define GPIO_DIR	0x04
125 
126 #define GPIO_IRQ_ENABLE	0x00
127 #define GPIO_IRQ_TYPE0	0x04
128 #define GPIO_IRQ_TYPE1	0x08
129 #define GPIO_IRQ_TYPE2	0x0c
130 #define GPIO_IRQ_STATUS	0x10
131 
132 #define GPIO_DEBOUNCE_SEL1 0x00
133 #define GPIO_DEBOUNCE_SEL2 0x04
134 
135 #define _GPIO_SET_DEBOUNCE(t, o, i) ((!!((t) & BIT(i))) << GPIO_OFFSET(o))
136 #define GPIO_SET_DEBOUNCE1(t, o) _GPIO_SET_DEBOUNCE(t, o, 1)
137 #define GPIO_SET_DEBOUNCE2(t, o) _GPIO_SET_DEBOUNCE(t, o, 0)
138 
139 static const struct aspeed_gpio_bank *to_bank(unsigned int offset)
140 {
141 	unsigned int bank = GPIO_BANK(offset);
142 
143 	WARN_ON(bank > ARRAY_SIZE(aspeed_gpio_banks));
144 	return &aspeed_gpio_banks[bank];
145 }
146 
147 static inline bool is_bank_props_sentinel(const struct aspeed_bank_props *props)
148 {
149 	return !(props->input || props->output);
150 }
151 
152 static inline const struct aspeed_bank_props *find_bank_props(
153 		struct aspeed_gpio *gpio, unsigned int offset)
154 {
155 	const struct aspeed_bank_props *props = gpio->config->props;
156 
157 	while (!is_bank_props_sentinel(props)) {
158 		if (props->bank == GPIO_BANK(offset))
159 			return props;
160 		props++;
161 	}
162 
163 	return NULL;
164 }
165 
166 static inline bool have_gpio(struct aspeed_gpio *gpio, unsigned int offset)
167 {
168 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
169 	const struct aspeed_gpio_bank *bank = to_bank(offset);
170 	unsigned int group = GPIO_OFFSET(offset) / 8;
171 
172 	return bank->names[group][0] != '\0' &&
173 		(!props || ((props->input | props->output) & GPIO_BIT(offset)));
174 }
175 
176 static inline bool have_input(struct aspeed_gpio *gpio, unsigned int offset)
177 {
178 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
179 
180 	return !props || (props->input & GPIO_BIT(offset));
181 }
182 
183 #define have_irq(g, o) have_input((g), (o))
184 #define have_debounce(g, o) have_input((g), (o))
185 
186 static inline bool have_output(struct aspeed_gpio *gpio, unsigned int offset)
187 {
188 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
189 
190 	return !props || (props->output & GPIO_BIT(offset));
191 }
192 
193 static void __iomem *bank_val_reg(struct aspeed_gpio *gpio,
194 		const struct aspeed_gpio_bank *bank,
195 		unsigned int reg)
196 {
197 	return gpio->base + bank->val_regs + reg;
198 }
199 
200 static void __iomem *bank_irq_reg(struct aspeed_gpio *gpio,
201 		const struct aspeed_gpio_bank *bank,
202 		unsigned int reg)
203 {
204 	return gpio->base + bank->irq_regs + reg;
205 }
206 
207 static int aspeed_gpio_get(struct gpio_chip *gc, unsigned int offset)
208 {
209 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
210 	const struct aspeed_gpio_bank *bank = to_bank(offset);
211 
212 	return !!(ioread32(bank_val_reg(gpio, bank, GPIO_DATA))
213 			& GPIO_BIT(offset));
214 }
215 
216 static void __aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
217 			      int val)
218 {
219 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
220 	const struct aspeed_gpio_bank *bank = to_bank(offset);
221 	void __iomem *addr;
222 	u32 reg;
223 
224 	addr = bank_val_reg(gpio, bank, GPIO_DATA);
225 	reg = ioread32(addr);
226 
227 	if (val)
228 		reg |= GPIO_BIT(offset);
229 	else
230 		reg &= ~GPIO_BIT(offset);
231 
232 	iowrite32(reg, addr);
233 }
234 
235 static void aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
236 			    int val)
237 {
238 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
239 	unsigned long flags;
240 
241 	spin_lock_irqsave(&gpio->lock, flags);
242 
243 	__aspeed_gpio_set(gc, offset, val);
244 
245 	spin_unlock_irqrestore(&gpio->lock, flags);
246 }
247 
248 static int aspeed_gpio_dir_in(struct gpio_chip *gc, unsigned int offset)
249 {
250 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
251 	const struct aspeed_gpio_bank *bank = to_bank(offset);
252 	unsigned long flags;
253 	u32 reg;
254 
255 	if (!have_input(gpio, offset))
256 		return -ENOTSUPP;
257 
258 	spin_lock_irqsave(&gpio->lock, flags);
259 
260 	reg = ioread32(bank_val_reg(gpio, bank, GPIO_DIR));
261 	iowrite32(reg & ~GPIO_BIT(offset), bank_val_reg(gpio, bank, GPIO_DIR));
262 
263 	spin_unlock_irqrestore(&gpio->lock, flags);
264 
265 	return 0;
266 }
267 
268 static int aspeed_gpio_dir_out(struct gpio_chip *gc,
269 			       unsigned int offset, int val)
270 {
271 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
272 	const struct aspeed_gpio_bank *bank = to_bank(offset);
273 	unsigned long flags;
274 	u32 reg;
275 
276 	if (!have_output(gpio, offset))
277 		return -ENOTSUPP;
278 
279 	spin_lock_irqsave(&gpio->lock, flags);
280 
281 	reg = ioread32(bank_val_reg(gpio, bank, GPIO_DIR));
282 	iowrite32(reg | GPIO_BIT(offset), bank_val_reg(gpio, bank, GPIO_DIR));
283 
284 	__aspeed_gpio_set(gc, offset, val);
285 
286 	spin_unlock_irqrestore(&gpio->lock, flags);
287 
288 	return 0;
289 }
290 
291 static int aspeed_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
292 {
293 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
294 	const struct aspeed_gpio_bank *bank = to_bank(offset);
295 	unsigned long flags;
296 	u32 val;
297 
298 	if (!have_input(gpio, offset))
299 		return 0;
300 
301 	if (!have_output(gpio, offset))
302 		return 1;
303 
304 	spin_lock_irqsave(&gpio->lock, flags);
305 
306 	val = ioread32(bank_val_reg(gpio, bank, GPIO_DIR)) & GPIO_BIT(offset);
307 
308 	spin_unlock_irqrestore(&gpio->lock, flags);
309 
310 	return !val;
311 
312 }
313 
314 static inline int irqd_to_aspeed_gpio_data(struct irq_data *d,
315 		struct aspeed_gpio **gpio,
316 		const struct aspeed_gpio_bank **bank,
317 		u32 *bit)
318 {
319 	int offset;
320 	struct aspeed_gpio *internal;
321 
322 	offset = irqd_to_hwirq(d);
323 
324 	internal = irq_data_get_irq_chip_data(d);
325 
326 	/* This might be a bit of a questionable place to check */
327 	if (!have_irq(internal, offset))
328 		return -ENOTSUPP;
329 
330 	*gpio = internal;
331 	*bank = to_bank(offset);
332 	*bit = GPIO_BIT(offset);
333 
334 	return 0;
335 }
336 
337 static void aspeed_gpio_irq_ack(struct irq_data *d)
338 {
339 	const struct aspeed_gpio_bank *bank;
340 	struct aspeed_gpio *gpio;
341 	unsigned long flags;
342 	void __iomem *status_addr;
343 	u32 bit;
344 	int rc;
345 
346 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit);
347 	if (rc)
348 		return;
349 
350 	status_addr = bank_irq_reg(gpio, bank, GPIO_IRQ_STATUS);
351 
352 	spin_lock_irqsave(&gpio->lock, flags);
353 	iowrite32(bit, status_addr);
354 	spin_unlock_irqrestore(&gpio->lock, flags);
355 }
356 
357 static void aspeed_gpio_irq_set_mask(struct irq_data *d, bool set)
358 {
359 	const struct aspeed_gpio_bank *bank;
360 	struct aspeed_gpio *gpio;
361 	unsigned long flags;
362 	u32 reg, bit;
363 	void __iomem *addr;
364 	int rc;
365 
366 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit);
367 	if (rc)
368 		return;
369 
370 	addr = bank_irq_reg(gpio, bank, GPIO_IRQ_ENABLE);
371 
372 	spin_lock_irqsave(&gpio->lock, flags);
373 
374 	reg = ioread32(addr);
375 	if (set)
376 		reg |= bit;
377 	else
378 		reg &= bit;
379 	iowrite32(reg, addr);
380 
381 	spin_unlock_irqrestore(&gpio->lock, flags);
382 }
383 
384 static void aspeed_gpio_irq_mask(struct irq_data *d)
385 {
386 	aspeed_gpio_irq_set_mask(d, false);
387 }
388 
389 static void aspeed_gpio_irq_unmask(struct irq_data *d)
390 {
391 	aspeed_gpio_irq_set_mask(d, true);
392 }
393 
394 static int aspeed_gpio_set_type(struct irq_data *d, unsigned int type)
395 {
396 	u32 type0 = 0;
397 	u32 type1 = 0;
398 	u32 type2 = 0;
399 	u32 bit, reg;
400 	const struct aspeed_gpio_bank *bank;
401 	irq_flow_handler_t handler;
402 	struct aspeed_gpio *gpio;
403 	unsigned long flags;
404 	void __iomem *addr;
405 	int rc;
406 
407 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit);
408 	if (rc)
409 		return -EINVAL;
410 
411 	switch (type & IRQ_TYPE_SENSE_MASK) {
412 	case IRQ_TYPE_EDGE_BOTH:
413 		type2 |= bit;
414 		/* fall through */
415 	case IRQ_TYPE_EDGE_RISING:
416 		type0 |= bit;
417 		/* fall through */
418 	case IRQ_TYPE_EDGE_FALLING:
419 		handler = handle_edge_irq;
420 		break;
421 	case IRQ_TYPE_LEVEL_HIGH:
422 		type0 |= bit;
423 		/* fall through */
424 	case IRQ_TYPE_LEVEL_LOW:
425 		type1 |= bit;
426 		handler = handle_level_irq;
427 		break;
428 	default:
429 		return -EINVAL;
430 	}
431 
432 	spin_lock_irqsave(&gpio->lock, flags);
433 
434 	addr = bank_irq_reg(gpio, bank, GPIO_IRQ_TYPE0);
435 	reg = ioread32(addr);
436 	reg = (reg & ~bit) | type0;
437 	iowrite32(reg, addr);
438 
439 	addr = bank_irq_reg(gpio, bank, GPIO_IRQ_TYPE1);
440 	reg = ioread32(addr);
441 	reg = (reg & ~bit) | type1;
442 	iowrite32(reg, addr);
443 
444 	addr = bank_irq_reg(gpio, bank, GPIO_IRQ_TYPE2);
445 	reg = ioread32(addr);
446 	reg = (reg & ~bit) | type2;
447 	iowrite32(reg, addr);
448 
449 	spin_unlock_irqrestore(&gpio->lock, flags);
450 
451 	irq_set_handler_locked(d, handler);
452 
453 	return 0;
454 }
455 
456 static void aspeed_gpio_irq_handler(struct irq_desc *desc)
457 {
458 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
459 	struct irq_chip *ic = irq_desc_get_chip(desc);
460 	struct aspeed_gpio *data = gpiochip_get_data(gc);
461 	unsigned int i, p, girq;
462 	unsigned long reg;
463 
464 	chained_irq_enter(ic, desc);
465 
466 	for (i = 0; i < ARRAY_SIZE(aspeed_gpio_banks); i++) {
467 		const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i];
468 
469 		reg = ioread32(bank_irq_reg(data, bank, GPIO_IRQ_STATUS));
470 
471 		for_each_set_bit(p, &reg, 32) {
472 			girq = irq_find_mapping(gc->irq.domain, i * 32 + p);
473 			generic_handle_irq(girq);
474 		}
475 
476 	}
477 
478 	chained_irq_exit(ic, desc);
479 }
480 
481 static struct irq_chip aspeed_gpio_irqchip = {
482 	.name		= "aspeed-gpio",
483 	.irq_ack	= aspeed_gpio_irq_ack,
484 	.irq_mask	= aspeed_gpio_irq_mask,
485 	.irq_unmask	= aspeed_gpio_irq_unmask,
486 	.irq_set_type	= aspeed_gpio_set_type,
487 };
488 
489 static void set_irq_valid_mask(struct aspeed_gpio *gpio)
490 {
491 	const struct aspeed_bank_props *props = gpio->config->props;
492 
493 	while (!is_bank_props_sentinel(props)) {
494 		unsigned int offset;
495 		const unsigned long int input = props->input;
496 
497 		/* Pretty crummy approach, but similar to GPIO core */
498 		for_each_clear_bit(offset, &input, 32) {
499 			unsigned int i = props->bank * 32 + offset;
500 
501 			if (i >= gpio->config->nr_gpios)
502 				break;
503 
504 			clear_bit(i, gpio->chip.irq.valid_mask);
505 		}
506 
507 		props++;
508 	}
509 }
510 
511 static int aspeed_gpio_setup_irqs(struct aspeed_gpio *gpio,
512 		struct platform_device *pdev)
513 {
514 	int rc;
515 
516 	rc = platform_get_irq(pdev, 0);
517 	if (rc < 0)
518 		return rc;
519 
520 	gpio->irq = rc;
521 
522 	set_irq_valid_mask(gpio);
523 
524 	rc = gpiochip_irqchip_add(&gpio->chip, &aspeed_gpio_irqchip,
525 			0, handle_bad_irq, IRQ_TYPE_NONE);
526 	if (rc) {
527 		dev_info(&pdev->dev, "Could not add irqchip\n");
528 		return rc;
529 	}
530 
531 	gpiochip_set_chained_irqchip(&gpio->chip, &aspeed_gpio_irqchip,
532 				     gpio->irq, aspeed_gpio_irq_handler);
533 
534 	return 0;
535 }
536 
537 static int aspeed_gpio_request(struct gpio_chip *chip, unsigned int offset)
538 {
539 	if (!have_gpio(gpiochip_get_data(chip), offset))
540 		return -ENODEV;
541 
542 	return pinctrl_gpio_request(chip->base + offset);
543 }
544 
545 static void aspeed_gpio_free(struct gpio_chip *chip, unsigned int offset)
546 {
547 	pinctrl_gpio_free(chip->base + offset);
548 }
549 
550 static inline void __iomem *bank_debounce_reg(struct aspeed_gpio *gpio,
551 		const struct aspeed_gpio_bank *bank,
552 		unsigned int reg)
553 {
554 	return gpio->base + bank->debounce_regs + reg;
555 }
556 
557 static int usecs_to_cycles(struct aspeed_gpio *gpio, unsigned long usecs,
558 		u32 *cycles)
559 {
560 	u64 rate;
561 	u64 n;
562 	u32 r;
563 
564 	rate = clk_get_rate(gpio->clk);
565 	if (!rate)
566 		return -ENOTSUPP;
567 
568 	n = rate * usecs;
569 	r = do_div(n, 1000000);
570 
571 	if (n >= U32_MAX)
572 		return -ERANGE;
573 
574 	/* At least as long as the requested time */
575 	*cycles = n + (!!r);
576 
577 	return 0;
578 }
579 
580 /* Call under gpio->lock */
581 static int register_allocated_timer(struct aspeed_gpio *gpio,
582 		unsigned int offset, unsigned int timer)
583 {
584 	if (WARN(gpio->offset_timer[offset] != 0,
585 				"Offset %d already allocated timer %d\n",
586 				offset, gpio->offset_timer[offset]))
587 		return -EINVAL;
588 
589 	if (WARN(gpio->timer_users[timer] == UINT_MAX,
590 				"Timer user count would overflow\n"))
591 		return -EPERM;
592 
593 	gpio->offset_timer[offset] = timer;
594 	gpio->timer_users[timer]++;
595 
596 	return 0;
597 }
598 
599 /* Call under gpio->lock */
600 static int unregister_allocated_timer(struct aspeed_gpio *gpio,
601 		unsigned int offset)
602 {
603 	if (WARN(gpio->offset_timer[offset] == 0,
604 				"No timer allocated to offset %d\n", offset))
605 		return -EINVAL;
606 
607 	if (WARN(gpio->timer_users[gpio->offset_timer[offset]] == 0,
608 				"No users recorded for timer %d\n",
609 				gpio->offset_timer[offset]))
610 		return -EINVAL;
611 
612 	gpio->timer_users[gpio->offset_timer[offset]]--;
613 	gpio->offset_timer[offset] = 0;
614 
615 	return 0;
616 }
617 
618 /* Call under gpio->lock */
619 static inline bool timer_allocation_registered(struct aspeed_gpio *gpio,
620 		unsigned int offset)
621 {
622 	return gpio->offset_timer[offset] > 0;
623 }
624 
625 /* Call under gpio->lock */
626 static void configure_timer(struct aspeed_gpio *gpio, unsigned int offset,
627 		unsigned int timer)
628 {
629 	const struct aspeed_gpio_bank *bank = to_bank(offset);
630 	const u32 mask = GPIO_BIT(offset);
631 	void __iomem *addr;
632 	u32 val;
633 
634 	addr = bank_debounce_reg(gpio, bank, GPIO_DEBOUNCE_SEL1);
635 	val = ioread32(addr);
636 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE1(timer, offset), addr);
637 
638 	addr = bank_debounce_reg(gpio, bank, GPIO_DEBOUNCE_SEL2);
639 	val = ioread32(addr);
640 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE2(timer, offset), addr);
641 }
642 
643 static int enable_debounce(struct gpio_chip *chip, unsigned int offset,
644 				    unsigned long usecs)
645 {
646 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
647 	u32 requested_cycles;
648 	unsigned long flags;
649 	int rc;
650 	int i;
651 
652 	if (!gpio->clk)
653 		return -EINVAL;
654 
655 	rc = usecs_to_cycles(gpio, usecs, &requested_cycles);
656 	if (rc < 0) {
657 		dev_warn(chip->parent, "Failed to convert %luus to cycles at %luHz: %d\n",
658 				usecs, clk_get_rate(gpio->clk), rc);
659 		return rc;
660 	}
661 
662 	spin_lock_irqsave(&gpio->lock, flags);
663 
664 	if (timer_allocation_registered(gpio, offset)) {
665 		rc = unregister_allocated_timer(gpio, offset);
666 		if (rc < 0)
667 			goto out;
668 	}
669 
670 	/* Try to find a timer already configured for the debounce period */
671 	for (i = 1; i < ARRAY_SIZE(debounce_timers); i++) {
672 		u32 cycles;
673 
674 		cycles = ioread32(gpio->base + debounce_timers[i]);
675 		if (requested_cycles == cycles)
676 			break;
677 	}
678 
679 	if (i == ARRAY_SIZE(debounce_timers)) {
680 		int j;
681 
682 		/*
683 		 * As there are no timers configured for the requested debounce
684 		 * period, find an unused timer instead
685 		 */
686 		for (j = 1; j < ARRAY_SIZE(gpio->timer_users); j++) {
687 			if (gpio->timer_users[j] == 0)
688 				break;
689 		}
690 
691 		if (j == ARRAY_SIZE(gpio->timer_users)) {
692 			dev_warn(chip->parent,
693 					"Debounce timers exhausted, cannot debounce for period %luus\n",
694 					usecs);
695 
696 			rc = -EPERM;
697 
698 			/*
699 			 * We already adjusted the accounting to remove @offset
700 			 * as a user of its previous timer, so also configure
701 			 * the hardware so @offset has timers disabled for
702 			 * consistency.
703 			 */
704 			configure_timer(gpio, offset, 0);
705 			goto out;
706 		}
707 
708 		i = j;
709 
710 		iowrite32(requested_cycles, gpio->base + debounce_timers[i]);
711 	}
712 
713 	if (WARN(i == 0, "Cannot register index of disabled timer\n")) {
714 		rc = -EINVAL;
715 		goto out;
716 	}
717 
718 	register_allocated_timer(gpio, offset, i);
719 	configure_timer(gpio, offset, i);
720 
721 out:
722 	spin_unlock_irqrestore(&gpio->lock, flags);
723 
724 	return rc;
725 }
726 
727 static int disable_debounce(struct gpio_chip *chip, unsigned int offset)
728 {
729 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
730 	unsigned long flags;
731 	int rc;
732 
733 	spin_lock_irqsave(&gpio->lock, flags);
734 
735 	rc = unregister_allocated_timer(gpio, offset);
736 	if (!rc)
737 		configure_timer(gpio, offset, 0);
738 
739 	spin_unlock_irqrestore(&gpio->lock, flags);
740 
741 	return rc;
742 }
743 
744 static int set_debounce(struct gpio_chip *chip, unsigned int offset,
745 				    unsigned long usecs)
746 {
747 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
748 
749 	if (!have_debounce(gpio, offset))
750 		return -ENOTSUPP;
751 
752 	if (usecs)
753 		return enable_debounce(chip, offset, usecs);
754 
755 	return disable_debounce(chip, offset);
756 }
757 
758 static int aspeed_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
759 				  unsigned long config)
760 {
761 	unsigned long param = pinconf_to_config_param(config);
762 	u32 arg = pinconf_to_config_argument(config);
763 
764 	if (param == PIN_CONFIG_INPUT_DEBOUNCE)
765 		return set_debounce(chip, offset, arg);
766 	else if (param == PIN_CONFIG_BIAS_DISABLE ||
767 			param == PIN_CONFIG_BIAS_PULL_DOWN ||
768 			param == PIN_CONFIG_DRIVE_STRENGTH)
769 		return pinctrl_gpio_set_config(offset, config);
770 	else if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN ||
771 			param == PIN_CONFIG_DRIVE_OPEN_SOURCE)
772 		/* Return -ENOTSUPP to trigger emulation, as per datasheet */
773 		return -ENOTSUPP;
774 
775 	return -ENOTSUPP;
776 }
777 
778 /*
779  * Any banks not specified in a struct aspeed_bank_props array are assumed to
780  * have the properties:
781  *
782  *     { .input = 0xffffffff, .output = 0xffffffff }
783  */
784 
785 static const struct aspeed_bank_props ast2400_bank_props[] = {
786 	/*     input	  output   */
787 	{ 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
788 	{ 6, 0x0000000f, 0x0fffff0f }, /* Y/Z/AA/AB, two 4-GPIO holes */
789 	{ },
790 };
791 
792 static const struct aspeed_gpio_config ast2400_config =
793 	/* 220 for simplicity, really 216 with two 4-GPIO holes, four at end */
794 	{ .nr_gpios = 220, .props = ast2400_bank_props, };
795 
796 static const struct aspeed_bank_props ast2500_bank_props[] = {
797 	/*     input	  output   */
798 	{ 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
799 	{ 6, 0x0fffffff, 0x0fffffff }, /* Y/Z/AA/AB, 4-GPIO hole */
800 	{ 7, 0x000000ff, 0x000000ff }, /* AC */
801 	{ },
802 };
803 
804 static const struct aspeed_gpio_config ast2500_config =
805 	/* 232 for simplicity, actual number is 228 (4-GPIO hole in GPIOAB) */
806 	{ .nr_gpios = 232, .props = ast2500_bank_props, };
807 
808 static const struct of_device_id aspeed_gpio_of_table[] = {
809 	{ .compatible = "aspeed,ast2400-gpio", .data = &ast2400_config, },
810 	{ .compatible = "aspeed,ast2500-gpio", .data = &ast2500_config, },
811 	{}
812 };
813 MODULE_DEVICE_TABLE(of, aspeed_gpio_of_table);
814 
815 static int __init aspeed_gpio_probe(struct platform_device *pdev)
816 {
817 	const struct of_device_id *gpio_id;
818 	struct aspeed_gpio *gpio;
819 	struct resource *res;
820 	int rc;
821 
822 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
823 	if (!gpio)
824 		return -ENOMEM;
825 
826 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
827 	gpio->base = devm_ioremap_resource(&pdev->dev, res);
828 	if (IS_ERR(gpio->base))
829 		return PTR_ERR(gpio->base);
830 
831 	spin_lock_init(&gpio->lock);
832 
833 	gpio_id = of_match_node(aspeed_gpio_of_table, pdev->dev.of_node);
834 	if (!gpio_id)
835 		return -EINVAL;
836 
837 	gpio->clk = of_clk_get(pdev->dev.of_node, 0);
838 	if (IS_ERR(gpio->clk)) {
839 		dev_warn(&pdev->dev,
840 				"Failed to get clock from devicetree, debouncing disabled\n");
841 		gpio->clk = NULL;
842 	}
843 
844 	gpio->config = gpio_id->data;
845 
846 	gpio->chip.parent = &pdev->dev;
847 	gpio->chip.ngpio = gpio->config->nr_gpios;
848 	gpio->chip.parent = &pdev->dev;
849 	gpio->chip.direction_input = aspeed_gpio_dir_in;
850 	gpio->chip.direction_output = aspeed_gpio_dir_out;
851 	gpio->chip.get_direction = aspeed_gpio_get_direction;
852 	gpio->chip.request = aspeed_gpio_request;
853 	gpio->chip.free = aspeed_gpio_free;
854 	gpio->chip.get = aspeed_gpio_get;
855 	gpio->chip.set = aspeed_gpio_set;
856 	gpio->chip.set_config = aspeed_gpio_set_config;
857 	gpio->chip.label = dev_name(&pdev->dev);
858 	gpio->chip.base = -1;
859 	gpio->chip.irq.need_valid_mask = true;
860 
861 	rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
862 	if (rc < 0)
863 		return rc;
864 
865 	gpio->offset_timer =
866 		devm_kzalloc(&pdev->dev, gpio->chip.ngpio, GFP_KERNEL);
867 
868 	return aspeed_gpio_setup_irqs(gpio, pdev);
869 }
870 
871 static struct platform_driver aspeed_gpio_driver = {
872 	.driver = {
873 		.name = KBUILD_MODNAME,
874 		.of_match_table = aspeed_gpio_of_table,
875 	},
876 };
877 
878 module_platform_driver_probe(aspeed_gpio_driver, aspeed_gpio_probe);
879 
880 MODULE_DESCRIPTION("Aspeed GPIO Driver");
881 MODULE_LICENSE("GPL");
882