xref: /openbmc/linux/drivers/gpio/gpio-aspeed.c (revision d2ba09c1)
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 	uint16_t	tolerance_regs;
64 	const char	names[4][3];
65 };
66 
67 static const int debounce_timers[4] = { 0x00, 0x50, 0x54, 0x58 };
68 
69 static const struct aspeed_gpio_bank aspeed_gpio_banks[] = {
70 	{
71 		.val_regs = 0x0000,
72 		.irq_regs = 0x0008,
73 		.debounce_regs = 0x0040,
74 		.tolerance_regs = 0x001c,
75 		.names = { "A", "B", "C", "D" },
76 	},
77 	{
78 		.val_regs = 0x0020,
79 		.irq_regs = 0x0028,
80 		.debounce_regs = 0x0048,
81 		.tolerance_regs = 0x003c,
82 		.names = { "E", "F", "G", "H" },
83 	},
84 	{
85 		.val_regs = 0x0070,
86 		.irq_regs = 0x0098,
87 		.debounce_regs = 0x00b0,
88 		.tolerance_regs = 0x00ac,
89 		.names = { "I", "J", "K", "L" },
90 	},
91 	{
92 		.val_regs = 0x0078,
93 		.irq_regs = 0x00e8,
94 		.debounce_regs = 0x0100,
95 		.tolerance_regs = 0x00fc,
96 		.names = { "M", "N", "O", "P" },
97 	},
98 	{
99 		.val_regs = 0x0080,
100 		.irq_regs = 0x0118,
101 		.debounce_regs = 0x0130,
102 		.tolerance_regs = 0x012c,
103 		.names = { "Q", "R", "S", "T" },
104 	},
105 	{
106 		.val_regs = 0x0088,
107 		.irq_regs = 0x0148,
108 		.debounce_regs = 0x0160,
109 		.tolerance_regs = 0x015c,
110 		.names = { "U", "V", "W", "X" },
111 	},
112 	{
113 		.val_regs = 0x01E0,
114 		.irq_regs = 0x0178,
115 		.debounce_regs = 0x0190,
116 		.tolerance_regs = 0x018c,
117 		.names = { "Y", "Z", "AA", "AB" },
118 	},
119 	{
120 		.val_regs = 0x01e8,
121 		.irq_regs = 0x01a8,
122 		.debounce_regs = 0x01c0,
123 		.tolerance_regs = 0x01bc,
124 		.names = { "AC", "", "", "" },
125 	},
126 };
127 
128 #define GPIO_BANK(x)	((x) >> 5)
129 #define GPIO_OFFSET(x)	((x) & 0x1f)
130 #define GPIO_BIT(x)	BIT(GPIO_OFFSET(x))
131 
132 #define GPIO_DATA	0x00
133 #define GPIO_DIR	0x04
134 
135 #define GPIO_IRQ_ENABLE	0x00
136 #define GPIO_IRQ_TYPE0	0x04
137 #define GPIO_IRQ_TYPE1	0x08
138 #define GPIO_IRQ_TYPE2	0x0c
139 #define GPIO_IRQ_STATUS	0x10
140 
141 #define GPIO_DEBOUNCE_SEL1 0x00
142 #define GPIO_DEBOUNCE_SEL2 0x04
143 
144 #define _GPIO_SET_DEBOUNCE(t, o, i) ((!!((t) & BIT(i))) << GPIO_OFFSET(o))
145 #define GPIO_SET_DEBOUNCE1(t, o) _GPIO_SET_DEBOUNCE(t, o, 1)
146 #define GPIO_SET_DEBOUNCE2(t, o) _GPIO_SET_DEBOUNCE(t, o, 0)
147 
148 static const struct aspeed_gpio_bank *to_bank(unsigned int offset)
149 {
150 	unsigned int bank = GPIO_BANK(offset);
151 
152 	WARN_ON(bank >= ARRAY_SIZE(aspeed_gpio_banks));
153 	return &aspeed_gpio_banks[bank];
154 }
155 
156 static inline bool is_bank_props_sentinel(const struct aspeed_bank_props *props)
157 {
158 	return !(props->input || props->output);
159 }
160 
161 static inline const struct aspeed_bank_props *find_bank_props(
162 		struct aspeed_gpio *gpio, unsigned int offset)
163 {
164 	const struct aspeed_bank_props *props = gpio->config->props;
165 
166 	while (!is_bank_props_sentinel(props)) {
167 		if (props->bank == GPIO_BANK(offset))
168 			return props;
169 		props++;
170 	}
171 
172 	return NULL;
173 }
174 
175 static inline bool have_gpio(struct aspeed_gpio *gpio, unsigned int offset)
176 {
177 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
178 	const struct aspeed_gpio_bank *bank = to_bank(offset);
179 	unsigned int group = GPIO_OFFSET(offset) / 8;
180 
181 	return bank->names[group][0] != '\0' &&
182 		(!props || ((props->input | props->output) & GPIO_BIT(offset)));
183 }
184 
185 static inline bool have_input(struct aspeed_gpio *gpio, unsigned int offset)
186 {
187 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
188 
189 	return !props || (props->input & GPIO_BIT(offset));
190 }
191 
192 #define have_irq(g, o) have_input((g), (o))
193 #define have_debounce(g, o) have_input((g), (o))
194 
195 static inline bool have_output(struct aspeed_gpio *gpio, unsigned int offset)
196 {
197 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
198 
199 	return !props || (props->output & GPIO_BIT(offset));
200 }
201 
202 static void __iomem *bank_val_reg(struct aspeed_gpio *gpio,
203 		const struct aspeed_gpio_bank *bank,
204 		unsigned int reg)
205 {
206 	return gpio->base + bank->val_regs + reg;
207 }
208 
209 static void __iomem *bank_irq_reg(struct aspeed_gpio *gpio,
210 		const struct aspeed_gpio_bank *bank,
211 		unsigned int reg)
212 {
213 	return gpio->base + bank->irq_regs + reg;
214 }
215 
216 static int aspeed_gpio_get(struct gpio_chip *gc, unsigned int offset)
217 {
218 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
219 	const struct aspeed_gpio_bank *bank = to_bank(offset);
220 
221 	return !!(ioread32(bank_val_reg(gpio, bank, GPIO_DATA))
222 			& GPIO_BIT(offset));
223 }
224 
225 static void __aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
226 			      int val)
227 {
228 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
229 	const struct aspeed_gpio_bank *bank = to_bank(offset);
230 	void __iomem *addr;
231 	u32 reg;
232 
233 	addr = bank_val_reg(gpio, bank, GPIO_DATA);
234 	reg = ioread32(addr);
235 
236 	if (val)
237 		reg |= GPIO_BIT(offset);
238 	else
239 		reg &= ~GPIO_BIT(offset);
240 
241 	iowrite32(reg, addr);
242 }
243 
244 static void aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
245 			    int val)
246 {
247 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
248 	unsigned long flags;
249 
250 	spin_lock_irqsave(&gpio->lock, flags);
251 
252 	__aspeed_gpio_set(gc, offset, val);
253 
254 	spin_unlock_irqrestore(&gpio->lock, flags);
255 }
256 
257 static int aspeed_gpio_dir_in(struct gpio_chip *gc, unsigned int offset)
258 {
259 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
260 	const struct aspeed_gpio_bank *bank = to_bank(offset);
261 	unsigned long flags;
262 	u32 reg;
263 
264 	if (!have_input(gpio, offset))
265 		return -ENOTSUPP;
266 
267 	spin_lock_irqsave(&gpio->lock, flags);
268 
269 	reg = ioread32(bank_val_reg(gpio, bank, GPIO_DIR));
270 	iowrite32(reg & ~GPIO_BIT(offset), bank_val_reg(gpio, bank, GPIO_DIR));
271 
272 	spin_unlock_irqrestore(&gpio->lock, flags);
273 
274 	return 0;
275 }
276 
277 static int aspeed_gpio_dir_out(struct gpio_chip *gc,
278 			       unsigned int offset, int val)
279 {
280 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
281 	const struct aspeed_gpio_bank *bank = to_bank(offset);
282 	unsigned long flags;
283 	u32 reg;
284 
285 	if (!have_output(gpio, offset))
286 		return -ENOTSUPP;
287 
288 	spin_lock_irqsave(&gpio->lock, flags);
289 
290 	reg = ioread32(bank_val_reg(gpio, bank, GPIO_DIR));
291 	iowrite32(reg | GPIO_BIT(offset), bank_val_reg(gpio, bank, GPIO_DIR));
292 
293 	__aspeed_gpio_set(gc, offset, val);
294 
295 	spin_unlock_irqrestore(&gpio->lock, flags);
296 
297 	return 0;
298 }
299 
300 static int aspeed_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
301 {
302 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
303 	const struct aspeed_gpio_bank *bank = to_bank(offset);
304 	unsigned long flags;
305 	u32 val;
306 
307 	if (!have_input(gpio, offset))
308 		return 0;
309 
310 	if (!have_output(gpio, offset))
311 		return 1;
312 
313 	spin_lock_irqsave(&gpio->lock, flags);
314 
315 	val = ioread32(bank_val_reg(gpio, bank, GPIO_DIR)) & GPIO_BIT(offset);
316 
317 	spin_unlock_irqrestore(&gpio->lock, flags);
318 
319 	return !val;
320 
321 }
322 
323 static inline int irqd_to_aspeed_gpio_data(struct irq_data *d,
324 		struct aspeed_gpio **gpio,
325 		const struct aspeed_gpio_bank **bank,
326 		u32 *bit)
327 {
328 	int offset;
329 	struct aspeed_gpio *internal;
330 
331 	offset = irqd_to_hwirq(d);
332 
333 	internal = irq_data_get_irq_chip_data(d);
334 
335 	/* This might be a bit of a questionable place to check */
336 	if (!have_irq(internal, offset))
337 		return -ENOTSUPP;
338 
339 	*gpio = internal;
340 	*bank = to_bank(offset);
341 	*bit = GPIO_BIT(offset);
342 
343 	return 0;
344 }
345 
346 static void aspeed_gpio_irq_ack(struct irq_data *d)
347 {
348 	const struct aspeed_gpio_bank *bank;
349 	struct aspeed_gpio *gpio;
350 	unsigned long flags;
351 	void __iomem *status_addr;
352 	u32 bit;
353 	int rc;
354 
355 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit);
356 	if (rc)
357 		return;
358 
359 	status_addr = bank_irq_reg(gpio, bank, GPIO_IRQ_STATUS);
360 
361 	spin_lock_irqsave(&gpio->lock, flags);
362 	iowrite32(bit, status_addr);
363 	spin_unlock_irqrestore(&gpio->lock, flags);
364 }
365 
366 static void aspeed_gpio_irq_set_mask(struct irq_data *d, bool set)
367 {
368 	const struct aspeed_gpio_bank *bank;
369 	struct aspeed_gpio *gpio;
370 	unsigned long flags;
371 	u32 reg, bit;
372 	void __iomem *addr;
373 	int rc;
374 
375 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit);
376 	if (rc)
377 		return;
378 
379 	addr = bank_irq_reg(gpio, bank, GPIO_IRQ_ENABLE);
380 
381 	spin_lock_irqsave(&gpio->lock, flags);
382 
383 	reg = ioread32(addr);
384 	if (set)
385 		reg |= bit;
386 	else
387 		reg &= ~bit;
388 	iowrite32(reg, addr);
389 
390 	spin_unlock_irqrestore(&gpio->lock, flags);
391 }
392 
393 static void aspeed_gpio_irq_mask(struct irq_data *d)
394 {
395 	aspeed_gpio_irq_set_mask(d, false);
396 }
397 
398 static void aspeed_gpio_irq_unmask(struct irq_data *d)
399 {
400 	aspeed_gpio_irq_set_mask(d, true);
401 }
402 
403 static int aspeed_gpio_set_type(struct irq_data *d, unsigned int type)
404 {
405 	u32 type0 = 0;
406 	u32 type1 = 0;
407 	u32 type2 = 0;
408 	u32 bit, reg;
409 	const struct aspeed_gpio_bank *bank;
410 	irq_flow_handler_t handler;
411 	struct aspeed_gpio *gpio;
412 	unsigned long flags;
413 	void __iomem *addr;
414 	int rc;
415 
416 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit);
417 	if (rc)
418 		return -EINVAL;
419 
420 	switch (type & IRQ_TYPE_SENSE_MASK) {
421 	case IRQ_TYPE_EDGE_BOTH:
422 		type2 |= bit;
423 		/* fall through */
424 	case IRQ_TYPE_EDGE_RISING:
425 		type0 |= bit;
426 		/* fall through */
427 	case IRQ_TYPE_EDGE_FALLING:
428 		handler = handle_edge_irq;
429 		break;
430 	case IRQ_TYPE_LEVEL_HIGH:
431 		type0 |= bit;
432 		/* fall through */
433 	case IRQ_TYPE_LEVEL_LOW:
434 		type1 |= bit;
435 		handler = handle_level_irq;
436 		break;
437 	default:
438 		return -EINVAL;
439 	}
440 
441 	spin_lock_irqsave(&gpio->lock, flags);
442 
443 	addr = bank_irq_reg(gpio, bank, GPIO_IRQ_TYPE0);
444 	reg = ioread32(addr);
445 	reg = (reg & ~bit) | type0;
446 	iowrite32(reg, addr);
447 
448 	addr = bank_irq_reg(gpio, bank, GPIO_IRQ_TYPE1);
449 	reg = ioread32(addr);
450 	reg = (reg & ~bit) | type1;
451 	iowrite32(reg, addr);
452 
453 	addr = bank_irq_reg(gpio, bank, GPIO_IRQ_TYPE2);
454 	reg = ioread32(addr);
455 	reg = (reg & ~bit) | type2;
456 	iowrite32(reg, addr);
457 
458 	spin_unlock_irqrestore(&gpio->lock, flags);
459 
460 	irq_set_handler_locked(d, handler);
461 
462 	return 0;
463 }
464 
465 static void aspeed_gpio_irq_handler(struct irq_desc *desc)
466 {
467 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
468 	struct irq_chip *ic = irq_desc_get_chip(desc);
469 	struct aspeed_gpio *data = gpiochip_get_data(gc);
470 	unsigned int i, p, girq;
471 	unsigned long reg;
472 
473 	chained_irq_enter(ic, desc);
474 
475 	for (i = 0; i < ARRAY_SIZE(aspeed_gpio_banks); i++) {
476 		const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i];
477 
478 		reg = ioread32(bank_irq_reg(data, bank, GPIO_IRQ_STATUS));
479 
480 		for_each_set_bit(p, &reg, 32) {
481 			girq = irq_find_mapping(gc->irq.domain, i * 32 + p);
482 			generic_handle_irq(girq);
483 		}
484 
485 	}
486 
487 	chained_irq_exit(ic, desc);
488 }
489 
490 static struct irq_chip aspeed_gpio_irqchip = {
491 	.name		= "aspeed-gpio",
492 	.irq_ack	= aspeed_gpio_irq_ack,
493 	.irq_mask	= aspeed_gpio_irq_mask,
494 	.irq_unmask	= aspeed_gpio_irq_unmask,
495 	.irq_set_type	= aspeed_gpio_set_type,
496 };
497 
498 static void set_irq_valid_mask(struct aspeed_gpio *gpio)
499 {
500 	const struct aspeed_bank_props *props = gpio->config->props;
501 
502 	while (!is_bank_props_sentinel(props)) {
503 		unsigned int offset;
504 		const unsigned long int input = props->input;
505 
506 		/* Pretty crummy approach, but similar to GPIO core */
507 		for_each_clear_bit(offset, &input, 32) {
508 			unsigned int i = props->bank * 32 + offset;
509 
510 			if (i >= gpio->config->nr_gpios)
511 				break;
512 
513 			clear_bit(i, gpio->chip.irq.valid_mask);
514 		}
515 
516 		props++;
517 	}
518 }
519 
520 static int aspeed_gpio_setup_irqs(struct aspeed_gpio *gpio,
521 		struct platform_device *pdev)
522 {
523 	int rc;
524 
525 	rc = platform_get_irq(pdev, 0);
526 	if (rc < 0)
527 		return rc;
528 
529 	gpio->irq = rc;
530 
531 	set_irq_valid_mask(gpio);
532 
533 	rc = gpiochip_irqchip_add(&gpio->chip, &aspeed_gpio_irqchip,
534 			0, handle_bad_irq, IRQ_TYPE_NONE);
535 	if (rc) {
536 		dev_info(&pdev->dev, "Could not add irqchip\n");
537 		return rc;
538 	}
539 
540 	gpiochip_set_chained_irqchip(&gpio->chip, &aspeed_gpio_irqchip,
541 				     gpio->irq, aspeed_gpio_irq_handler);
542 
543 	return 0;
544 }
545 
546 static int aspeed_gpio_reset_tolerance(struct gpio_chip *chip,
547 					unsigned int offset, bool enable)
548 {
549 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
550 	const struct aspeed_gpio_bank *bank;
551 	unsigned long flags;
552 	u32 val;
553 
554 	bank = to_bank(offset);
555 
556 	spin_lock_irqsave(&gpio->lock, flags);
557 	val = readl(gpio->base + bank->tolerance_regs);
558 
559 	if (enable)
560 		val |= GPIO_BIT(offset);
561 	else
562 		val &= ~GPIO_BIT(offset);
563 
564 	writel(val, gpio->base + bank->tolerance_regs);
565 	spin_unlock_irqrestore(&gpio->lock, flags);
566 
567 	return 0;
568 }
569 
570 static int aspeed_gpio_request(struct gpio_chip *chip, unsigned int offset)
571 {
572 	if (!have_gpio(gpiochip_get_data(chip), offset))
573 		return -ENODEV;
574 
575 	return pinctrl_gpio_request(chip->base + offset);
576 }
577 
578 static void aspeed_gpio_free(struct gpio_chip *chip, unsigned int offset)
579 {
580 	pinctrl_gpio_free(chip->base + offset);
581 }
582 
583 static inline void __iomem *bank_debounce_reg(struct aspeed_gpio *gpio,
584 		const struct aspeed_gpio_bank *bank,
585 		unsigned int reg)
586 {
587 	return gpio->base + bank->debounce_regs + reg;
588 }
589 
590 static int usecs_to_cycles(struct aspeed_gpio *gpio, unsigned long usecs,
591 		u32 *cycles)
592 {
593 	u64 rate;
594 	u64 n;
595 	u32 r;
596 
597 	rate = clk_get_rate(gpio->clk);
598 	if (!rate)
599 		return -ENOTSUPP;
600 
601 	n = rate * usecs;
602 	r = do_div(n, 1000000);
603 
604 	if (n >= U32_MAX)
605 		return -ERANGE;
606 
607 	/* At least as long as the requested time */
608 	*cycles = n + (!!r);
609 
610 	return 0;
611 }
612 
613 /* Call under gpio->lock */
614 static int register_allocated_timer(struct aspeed_gpio *gpio,
615 		unsigned int offset, unsigned int timer)
616 {
617 	if (WARN(gpio->offset_timer[offset] != 0,
618 				"Offset %d already allocated timer %d\n",
619 				offset, gpio->offset_timer[offset]))
620 		return -EINVAL;
621 
622 	if (WARN(gpio->timer_users[timer] == UINT_MAX,
623 				"Timer user count would overflow\n"))
624 		return -EPERM;
625 
626 	gpio->offset_timer[offset] = timer;
627 	gpio->timer_users[timer]++;
628 
629 	return 0;
630 }
631 
632 /* Call under gpio->lock */
633 static int unregister_allocated_timer(struct aspeed_gpio *gpio,
634 		unsigned int offset)
635 {
636 	if (WARN(gpio->offset_timer[offset] == 0,
637 				"No timer allocated to offset %d\n", offset))
638 		return -EINVAL;
639 
640 	if (WARN(gpio->timer_users[gpio->offset_timer[offset]] == 0,
641 				"No users recorded for timer %d\n",
642 				gpio->offset_timer[offset]))
643 		return -EINVAL;
644 
645 	gpio->timer_users[gpio->offset_timer[offset]]--;
646 	gpio->offset_timer[offset] = 0;
647 
648 	return 0;
649 }
650 
651 /* Call under gpio->lock */
652 static inline bool timer_allocation_registered(struct aspeed_gpio *gpio,
653 		unsigned int offset)
654 {
655 	return gpio->offset_timer[offset] > 0;
656 }
657 
658 /* Call under gpio->lock */
659 static void configure_timer(struct aspeed_gpio *gpio, unsigned int offset,
660 		unsigned int timer)
661 {
662 	const struct aspeed_gpio_bank *bank = to_bank(offset);
663 	const u32 mask = GPIO_BIT(offset);
664 	void __iomem *addr;
665 	u32 val;
666 
667 	addr = bank_debounce_reg(gpio, bank, GPIO_DEBOUNCE_SEL1);
668 	val = ioread32(addr);
669 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE1(timer, offset), addr);
670 
671 	addr = bank_debounce_reg(gpio, bank, GPIO_DEBOUNCE_SEL2);
672 	val = ioread32(addr);
673 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE2(timer, offset), addr);
674 }
675 
676 static int enable_debounce(struct gpio_chip *chip, unsigned int offset,
677 				    unsigned long usecs)
678 {
679 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
680 	u32 requested_cycles;
681 	unsigned long flags;
682 	int rc;
683 	int i;
684 
685 	if (!gpio->clk)
686 		return -EINVAL;
687 
688 	rc = usecs_to_cycles(gpio, usecs, &requested_cycles);
689 	if (rc < 0) {
690 		dev_warn(chip->parent, "Failed to convert %luus to cycles at %luHz: %d\n",
691 				usecs, clk_get_rate(gpio->clk), rc);
692 		return rc;
693 	}
694 
695 	spin_lock_irqsave(&gpio->lock, flags);
696 
697 	if (timer_allocation_registered(gpio, offset)) {
698 		rc = unregister_allocated_timer(gpio, offset);
699 		if (rc < 0)
700 			goto out;
701 	}
702 
703 	/* Try to find a timer already configured for the debounce period */
704 	for (i = 1; i < ARRAY_SIZE(debounce_timers); i++) {
705 		u32 cycles;
706 
707 		cycles = ioread32(gpio->base + debounce_timers[i]);
708 		if (requested_cycles == cycles)
709 			break;
710 	}
711 
712 	if (i == ARRAY_SIZE(debounce_timers)) {
713 		int j;
714 
715 		/*
716 		 * As there are no timers configured for the requested debounce
717 		 * period, find an unused timer instead
718 		 */
719 		for (j = 1; j < ARRAY_SIZE(gpio->timer_users); j++) {
720 			if (gpio->timer_users[j] == 0)
721 				break;
722 		}
723 
724 		if (j == ARRAY_SIZE(gpio->timer_users)) {
725 			dev_warn(chip->parent,
726 					"Debounce timers exhausted, cannot debounce for period %luus\n",
727 					usecs);
728 
729 			rc = -EPERM;
730 
731 			/*
732 			 * We already adjusted the accounting to remove @offset
733 			 * as a user of its previous timer, so also configure
734 			 * the hardware so @offset has timers disabled for
735 			 * consistency.
736 			 */
737 			configure_timer(gpio, offset, 0);
738 			goto out;
739 		}
740 
741 		i = j;
742 
743 		iowrite32(requested_cycles, gpio->base + debounce_timers[i]);
744 	}
745 
746 	if (WARN(i == 0, "Cannot register index of disabled timer\n")) {
747 		rc = -EINVAL;
748 		goto out;
749 	}
750 
751 	register_allocated_timer(gpio, offset, i);
752 	configure_timer(gpio, offset, i);
753 
754 out:
755 	spin_unlock_irqrestore(&gpio->lock, flags);
756 
757 	return rc;
758 }
759 
760 static int disable_debounce(struct gpio_chip *chip, unsigned int offset)
761 {
762 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
763 	unsigned long flags;
764 	int rc;
765 
766 	spin_lock_irqsave(&gpio->lock, flags);
767 
768 	rc = unregister_allocated_timer(gpio, offset);
769 	if (!rc)
770 		configure_timer(gpio, offset, 0);
771 
772 	spin_unlock_irqrestore(&gpio->lock, flags);
773 
774 	return rc;
775 }
776 
777 static int set_debounce(struct gpio_chip *chip, unsigned int offset,
778 				    unsigned long usecs)
779 {
780 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
781 
782 	if (!have_debounce(gpio, offset))
783 		return -ENOTSUPP;
784 
785 	if (usecs)
786 		return enable_debounce(chip, offset, usecs);
787 
788 	return disable_debounce(chip, offset);
789 }
790 
791 static int aspeed_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
792 				  unsigned long config)
793 {
794 	unsigned long param = pinconf_to_config_param(config);
795 	u32 arg = pinconf_to_config_argument(config);
796 
797 	if (param == PIN_CONFIG_INPUT_DEBOUNCE)
798 		return set_debounce(chip, offset, arg);
799 	else if (param == PIN_CONFIG_BIAS_DISABLE ||
800 			param == PIN_CONFIG_BIAS_PULL_DOWN ||
801 			param == PIN_CONFIG_DRIVE_STRENGTH)
802 		return pinctrl_gpio_set_config(offset, config);
803 	else if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN ||
804 			param == PIN_CONFIG_DRIVE_OPEN_SOURCE)
805 		/* Return -ENOTSUPP to trigger emulation, as per datasheet */
806 		return -ENOTSUPP;
807 	else if (param == PIN_CONFIG_PERSIST_STATE)
808 		return aspeed_gpio_reset_tolerance(chip, offset, arg);
809 
810 	return -ENOTSUPP;
811 }
812 
813 /*
814  * Any banks not specified in a struct aspeed_bank_props array are assumed to
815  * have the properties:
816  *
817  *     { .input = 0xffffffff, .output = 0xffffffff }
818  */
819 
820 static const struct aspeed_bank_props ast2400_bank_props[] = {
821 	/*     input	  output   */
822 	{ 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
823 	{ 6, 0x0000000f, 0x0fffff0f }, /* Y/Z/AA/AB, two 4-GPIO holes */
824 	{ },
825 };
826 
827 static const struct aspeed_gpio_config ast2400_config =
828 	/* 220 for simplicity, really 216 with two 4-GPIO holes, four at end */
829 	{ .nr_gpios = 220, .props = ast2400_bank_props, };
830 
831 static const struct aspeed_bank_props ast2500_bank_props[] = {
832 	/*     input	  output   */
833 	{ 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
834 	{ 6, 0x0fffffff, 0x0fffffff }, /* Y/Z/AA/AB, 4-GPIO hole */
835 	{ 7, 0x000000ff, 0x000000ff }, /* AC */
836 	{ },
837 };
838 
839 static const struct aspeed_gpio_config ast2500_config =
840 	/* 232 for simplicity, actual number is 228 (4-GPIO hole in GPIOAB) */
841 	{ .nr_gpios = 232, .props = ast2500_bank_props, };
842 
843 static const struct of_device_id aspeed_gpio_of_table[] = {
844 	{ .compatible = "aspeed,ast2400-gpio", .data = &ast2400_config, },
845 	{ .compatible = "aspeed,ast2500-gpio", .data = &ast2500_config, },
846 	{}
847 };
848 MODULE_DEVICE_TABLE(of, aspeed_gpio_of_table);
849 
850 static int __init aspeed_gpio_probe(struct platform_device *pdev)
851 {
852 	const struct of_device_id *gpio_id;
853 	struct aspeed_gpio *gpio;
854 	struct resource *res;
855 	int rc;
856 
857 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
858 	if (!gpio)
859 		return -ENOMEM;
860 
861 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
862 	gpio->base = devm_ioremap_resource(&pdev->dev, res);
863 	if (IS_ERR(gpio->base))
864 		return PTR_ERR(gpio->base);
865 
866 	spin_lock_init(&gpio->lock);
867 
868 	gpio_id = of_match_node(aspeed_gpio_of_table, pdev->dev.of_node);
869 	if (!gpio_id)
870 		return -EINVAL;
871 
872 	gpio->clk = of_clk_get(pdev->dev.of_node, 0);
873 	if (IS_ERR(gpio->clk)) {
874 		dev_warn(&pdev->dev,
875 				"Failed to get clock from devicetree, debouncing disabled\n");
876 		gpio->clk = NULL;
877 	}
878 
879 	gpio->config = gpio_id->data;
880 
881 	gpio->chip.parent = &pdev->dev;
882 	gpio->chip.ngpio = gpio->config->nr_gpios;
883 	gpio->chip.parent = &pdev->dev;
884 	gpio->chip.direction_input = aspeed_gpio_dir_in;
885 	gpio->chip.direction_output = aspeed_gpio_dir_out;
886 	gpio->chip.get_direction = aspeed_gpio_get_direction;
887 	gpio->chip.request = aspeed_gpio_request;
888 	gpio->chip.free = aspeed_gpio_free;
889 	gpio->chip.get = aspeed_gpio_get;
890 	gpio->chip.set = aspeed_gpio_set;
891 	gpio->chip.set_config = aspeed_gpio_set_config;
892 	gpio->chip.label = dev_name(&pdev->dev);
893 	gpio->chip.base = -1;
894 	gpio->chip.irq.need_valid_mask = true;
895 
896 	rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
897 	if (rc < 0)
898 		return rc;
899 
900 	gpio->offset_timer =
901 		devm_kzalloc(&pdev->dev, gpio->chip.ngpio, GFP_KERNEL);
902 
903 	return aspeed_gpio_setup_irqs(gpio, pdev);
904 }
905 
906 static struct platform_driver aspeed_gpio_driver = {
907 	.driver = {
908 		.name = KBUILD_MODNAME,
909 		.of_match_table = aspeed_gpio_of_table,
910 	},
911 };
912 
913 module_platform_driver_probe(aspeed_gpio_driver, aspeed_gpio_probe);
914 
915 MODULE_DESCRIPTION("Aspeed GPIO Driver");
916 MODULE_LICENSE("GPL");
917