xref: /openbmc/linux/drivers/gpio/gpio-aspeed.c (revision 2fa49589)
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/gpio/aspeed.h>
16 #include <linux/hashtable.h>
17 #include <linux/init.h>
18 #include <linux/io.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/pinctrl/consumer.h>
22 #include <linux/platform_device.h>
23 #include <linux/spinlock.h>
24 #include <linux/string.h>
25 
26 /*
27  * These two headers aren't meant to be used by GPIO drivers. We need
28  * them in order to access gpio_chip_hwgpio() which we need to implement
29  * the aspeed specific API which allows the coprocessor to request
30  * access to some GPIOs and to arbitrate between coprocessor and ARM.
31  */
32 #include <linux/gpio/consumer.h>
33 #include "gpiolib.h"
34 
35 struct aspeed_bank_props {
36 	unsigned int bank;
37 	u32 input;
38 	u32 output;
39 };
40 
41 struct aspeed_gpio_config {
42 	unsigned int nr_gpios;
43 	const struct aspeed_bank_props *props;
44 };
45 
46 /*
47  * @offset_timer: Maps an offset to an @timer_users index, or zero if disabled
48  * @timer_users: Tracks the number of users for each timer
49  *
50  * The @timer_users has four elements but the first element is unused. This is
51  * to simplify accounting and indexing, as a zero value in @offset_timer
52  * represents disabled debouncing for the GPIO. Any other value for an element
53  * of @offset_timer is used as an index into @timer_users. This behaviour of
54  * the zero value aligns with the behaviour of zero built from the timer
55  * configuration registers (i.e. debouncing is disabled).
56  */
57 struct aspeed_gpio {
58 	struct gpio_chip chip;
59 	spinlock_t lock;
60 	void __iomem *base;
61 	int irq;
62 	const struct aspeed_gpio_config *config;
63 
64 	u8 *offset_timer;
65 	unsigned int timer_users[4];
66 	struct clk *clk;
67 
68 	u32 *dcache;
69 	u8 *cf_copro_bankmap;
70 };
71 
72 struct aspeed_gpio_bank {
73 	uint16_t	val_regs;	/* +0: Rd: read input value, Wr: set write latch
74 					 * +4: Rd/Wr: Direction (0=in, 1=out)
75 					 */
76 	uint16_t	rdata_reg;	/*     Rd: read write latch, Wr: <none>  */
77 	uint16_t	irq_regs;
78 	uint16_t	debounce_regs;
79 	uint16_t	tolerance_regs;
80 	uint16_t	cmdsrc_regs;
81 	const char	names[4][3];
82 };
83 
84 /*
85  * Note: The "value" register returns the input value sampled on the
86  *       line even when the GPIO is configured as an output. Since
87  *       that input goes through synchronizers, writing, then reading
88  *       back may not return the written value right away.
89  *
90  *       The "rdata" register returns the content of the write latch
91  *       and thus can be used to read back what was last written
92  *       reliably.
93  */
94 
95 static const int debounce_timers[4] = { 0x00, 0x50, 0x54, 0x58 };
96 
97 static const struct aspeed_gpio_copro_ops *copro_ops;
98 static void *copro_data;
99 
100 static const struct aspeed_gpio_bank aspeed_gpio_banks[] = {
101 	{
102 		.val_regs = 0x0000,
103 		.rdata_reg = 0x00c0,
104 		.irq_regs = 0x0008,
105 		.debounce_regs = 0x0040,
106 		.tolerance_regs = 0x001c,
107 		.cmdsrc_regs = 0x0060,
108 		.names = { "A", "B", "C", "D" },
109 	},
110 	{
111 		.val_regs = 0x0020,
112 		.rdata_reg = 0x00c4,
113 		.irq_regs = 0x0028,
114 		.debounce_regs = 0x0048,
115 		.tolerance_regs = 0x003c,
116 		.cmdsrc_regs = 0x0068,
117 		.names = { "E", "F", "G", "H" },
118 	},
119 	{
120 		.val_regs = 0x0070,
121 		.rdata_reg = 0x00c8,
122 		.irq_regs = 0x0098,
123 		.debounce_regs = 0x00b0,
124 		.tolerance_regs = 0x00ac,
125 		.cmdsrc_regs = 0x0090,
126 		.names = { "I", "J", "K", "L" },
127 	},
128 	{
129 		.val_regs = 0x0078,
130 		.rdata_reg = 0x00cc,
131 		.irq_regs = 0x00e8,
132 		.debounce_regs = 0x0100,
133 		.tolerance_regs = 0x00fc,
134 		.cmdsrc_regs = 0x00e0,
135 		.names = { "M", "N", "O", "P" },
136 	},
137 	{
138 		.val_regs = 0x0080,
139 		.rdata_reg = 0x00d0,
140 		.irq_regs = 0x0118,
141 		.debounce_regs = 0x0130,
142 		.tolerance_regs = 0x012c,
143 		.cmdsrc_regs = 0x0110,
144 		.names = { "Q", "R", "S", "T" },
145 	},
146 	{
147 		.val_regs = 0x0088,
148 		.rdata_reg = 0x00d4,
149 		.irq_regs = 0x0148,
150 		.debounce_regs = 0x0160,
151 		.tolerance_regs = 0x015c,
152 		.cmdsrc_regs = 0x0140,
153 		.names = { "U", "V", "W", "X" },
154 	},
155 	{
156 		.val_regs = 0x01E0,
157 		.rdata_reg = 0x00d8,
158 		.irq_regs = 0x0178,
159 		.debounce_regs = 0x0190,
160 		.tolerance_regs = 0x018c,
161 		.cmdsrc_regs = 0x0170,
162 		.names = { "Y", "Z", "AA", "AB" },
163 	},
164 	{
165 		.val_regs = 0x01e8,
166 		.rdata_reg = 0x00dc,
167 		.irq_regs = 0x01a8,
168 		.debounce_regs = 0x01c0,
169 		.tolerance_regs = 0x01bc,
170 		.cmdsrc_regs = 0x01a0,
171 		.names = { "AC", "", "", "" },
172 	},
173 };
174 
175 enum aspeed_gpio_reg {
176 	reg_val,
177 	reg_rdata,
178 	reg_dir,
179 	reg_irq_enable,
180 	reg_irq_type0,
181 	reg_irq_type1,
182 	reg_irq_type2,
183 	reg_irq_status,
184 	reg_debounce_sel1,
185 	reg_debounce_sel2,
186 	reg_tolerance,
187 	reg_cmdsrc0,
188 	reg_cmdsrc1,
189 };
190 
191 #define GPIO_VAL_VALUE	0x00
192 #define GPIO_VAL_DIR	0x04
193 
194 #define GPIO_IRQ_ENABLE	0x00
195 #define GPIO_IRQ_TYPE0	0x04
196 #define GPIO_IRQ_TYPE1	0x08
197 #define GPIO_IRQ_TYPE2	0x0c
198 #define GPIO_IRQ_STATUS	0x10
199 
200 #define GPIO_DEBOUNCE_SEL1 0x00
201 #define GPIO_DEBOUNCE_SEL2 0x04
202 
203 #define GPIO_CMDSRC_0	0x00
204 #define GPIO_CMDSRC_1	0x04
205 #define  GPIO_CMDSRC_ARM		0
206 #define  GPIO_CMDSRC_LPC		1
207 #define  GPIO_CMDSRC_COLDFIRE		2
208 #define  GPIO_CMDSRC_RESERVED		3
209 
210 /* This will be resolved at compile time */
211 static inline void __iomem *bank_reg(struct aspeed_gpio *gpio,
212 				     const struct aspeed_gpio_bank *bank,
213 				     const enum aspeed_gpio_reg reg)
214 {
215 	switch (reg) {
216 	case reg_val:
217 		return gpio->base + bank->val_regs + GPIO_VAL_VALUE;
218 	case reg_rdata:
219 		return gpio->base + bank->rdata_reg;
220 	case reg_dir:
221 		return gpio->base + bank->val_regs + GPIO_VAL_DIR;
222 	case reg_irq_enable:
223 		return gpio->base + bank->irq_regs + GPIO_IRQ_ENABLE;
224 	case reg_irq_type0:
225 		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE0;
226 	case reg_irq_type1:
227 		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE1;
228 	case reg_irq_type2:
229 		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE2;
230 	case reg_irq_status:
231 		return gpio->base + bank->irq_regs + GPIO_IRQ_STATUS;
232 	case reg_debounce_sel1:
233 		return gpio->base + bank->debounce_regs + GPIO_DEBOUNCE_SEL1;
234 	case reg_debounce_sel2:
235 		return gpio->base + bank->debounce_regs + GPIO_DEBOUNCE_SEL2;
236 	case reg_tolerance:
237 		return gpio->base + bank->tolerance_regs;
238 	case reg_cmdsrc0:
239 		return gpio->base + bank->cmdsrc_regs + GPIO_CMDSRC_0;
240 	case reg_cmdsrc1:
241 		return gpio->base + bank->cmdsrc_regs + GPIO_CMDSRC_1;
242 	}
243 	BUG();
244 }
245 
246 #define GPIO_BANK(x)	((x) >> 5)
247 #define GPIO_OFFSET(x)	((x) & 0x1f)
248 #define GPIO_BIT(x)	BIT(GPIO_OFFSET(x))
249 
250 #define _GPIO_SET_DEBOUNCE(t, o, i) ((!!((t) & BIT(i))) << GPIO_OFFSET(o))
251 #define GPIO_SET_DEBOUNCE1(t, o) _GPIO_SET_DEBOUNCE(t, o, 1)
252 #define GPIO_SET_DEBOUNCE2(t, o) _GPIO_SET_DEBOUNCE(t, o, 0)
253 
254 static const struct aspeed_gpio_bank *to_bank(unsigned int offset)
255 {
256 	unsigned int bank = GPIO_BANK(offset);
257 
258 	WARN_ON(bank >= ARRAY_SIZE(aspeed_gpio_banks));
259 	return &aspeed_gpio_banks[bank];
260 }
261 
262 static inline bool is_bank_props_sentinel(const struct aspeed_bank_props *props)
263 {
264 	return !(props->input || props->output);
265 }
266 
267 static inline const struct aspeed_bank_props *find_bank_props(
268 		struct aspeed_gpio *gpio, unsigned int offset)
269 {
270 	const struct aspeed_bank_props *props = gpio->config->props;
271 
272 	while (!is_bank_props_sentinel(props)) {
273 		if (props->bank == GPIO_BANK(offset))
274 			return props;
275 		props++;
276 	}
277 
278 	return NULL;
279 }
280 
281 static inline bool have_gpio(struct aspeed_gpio *gpio, unsigned int offset)
282 {
283 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
284 	const struct aspeed_gpio_bank *bank = to_bank(offset);
285 	unsigned int group = GPIO_OFFSET(offset) / 8;
286 
287 	return bank->names[group][0] != '\0' &&
288 		(!props || ((props->input | props->output) & GPIO_BIT(offset)));
289 }
290 
291 static inline bool have_input(struct aspeed_gpio *gpio, unsigned int offset)
292 {
293 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
294 
295 	return !props || (props->input & GPIO_BIT(offset));
296 }
297 
298 #define have_irq(g, o) have_input((g), (o))
299 #define have_debounce(g, o) have_input((g), (o))
300 
301 static inline bool have_output(struct aspeed_gpio *gpio, unsigned int offset)
302 {
303 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
304 
305 	return !props || (props->output & GPIO_BIT(offset));
306 }
307 
308 static void aspeed_gpio_change_cmd_source(struct aspeed_gpio *gpio,
309 					  const struct aspeed_gpio_bank *bank,
310 					  int bindex, int cmdsrc)
311 {
312 	void __iomem *c0 = bank_reg(gpio, bank, reg_cmdsrc0);
313 	void __iomem *c1 = bank_reg(gpio, bank, reg_cmdsrc1);
314 	u32 bit, reg;
315 
316 	/*
317 	 * Each register controls 4 banks, so take the bottom 2
318 	 * bits of the bank index, and use them to select the
319 	 * right control bit (0, 8, 16 or 24).
320 	 */
321 	bit = BIT((bindex & 3) << 3);
322 
323 	/* Source 1 first to avoid illegal 11 combination */
324 	reg = ioread32(c1);
325 	if (cmdsrc & 2)
326 		reg |= bit;
327 	else
328 		reg &= ~bit;
329 	iowrite32(reg, c1);
330 
331 	/* Then Source 0 */
332 	reg = ioread32(c0);
333 	if (cmdsrc & 1)
334 		reg |= bit;
335 	else
336 		reg &= ~bit;
337 	iowrite32(reg, c0);
338 }
339 
340 static bool aspeed_gpio_copro_request(struct aspeed_gpio *gpio,
341 				      unsigned int offset)
342 {
343 	const struct aspeed_gpio_bank *bank = to_bank(offset);
344 
345 	if (!copro_ops || !gpio->cf_copro_bankmap)
346 		return false;
347 	if (!gpio->cf_copro_bankmap[offset >> 3])
348 		return false;
349 	if (!copro_ops->request_access)
350 		return false;
351 
352 	/* Pause the coprocessor */
353 	copro_ops->request_access(copro_data);
354 
355 	/* Change command source back to ARM */
356 	aspeed_gpio_change_cmd_source(gpio, bank, offset >> 3, GPIO_CMDSRC_ARM);
357 
358 	/* Update cache */
359 	gpio->dcache[GPIO_BANK(offset)] = ioread32(bank_reg(gpio, bank, reg_rdata));
360 
361 	return true;
362 }
363 
364 static void aspeed_gpio_copro_release(struct aspeed_gpio *gpio,
365 				      unsigned int offset)
366 {
367 	const struct aspeed_gpio_bank *bank = to_bank(offset);
368 
369 	if (!copro_ops || !gpio->cf_copro_bankmap)
370 		return;
371 	if (!gpio->cf_copro_bankmap[offset >> 3])
372 		return;
373 	if (!copro_ops->release_access)
374 		return;
375 
376 	/* Change command source back to ColdFire */
377 	aspeed_gpio_change_cmd_source(gpio, bank, offset >> 3,
378 				      GPIO_CMDSRC_COLDFIRE);
379 
380 	/* Restart the coprocessor */
381 	copro_ops->release_access(copro_data);
382 }
383 
384 static int aspeed_gpio_get(struct gpio_chip *gc, unsigned int offset)
385 {
386 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
387 	const struct aspeed_gpio_bank *bank = to_bank(offset);
388 
389 	return !!(ioread32(bank_reg(gpio, bank, reg_val)) & GPIO_BIT(offset));
390 }
391 
392 static void __aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
393 			      int val)
394 {
395 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
396 	const struct aspeed_gpio_bank *bank = to_bank(offset);
397 	void __iomem *addr;
398 	u32 reg;
399 
400 	addr = bank_reg(gpio, bank, reg_val);
401 	reg = gpio->dcache[GPIO_BANK(offset)];
402 
403 	if (val)
404 		reg |= GPIO_BIT(offset);
405 	else
406 		reg &= ~GPIO_BIT(offset);
407 	gpio->dcache[GPIO_BANK(offset)] = reg;
408 
409 	iowrite32(reg, addr);
410 }
411 
412 static void aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
413 			    int val)
414 {
415 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
416 	unsigned long flags;
417 	bool copro;
418 
419 	spin_lock_irqsave(&gpio->lock, flags);
420 	copro = aspeed_gpio_copro_request(gpio, offset);
421 
422 	__aspeed_gpio_set(gc, offset, val);
423 
424 	if (copro)
425 		aspeed_gpio_copro_release(gpio, offset);
426 	spin_unlock_irqrestore(&gpio->lock, flags);
427 }
428 
429 static int aspeed_gpio_dir_in(struct gpio_chip *gc, unsigned int offset)
430 {
431 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
432 	const struct aspeed_gpio_bank *bank = to_bank(offset);
433 	void __iomem *addr = bank_reg(gpio, bank, reg_dir);
434 	unsigned long flags;
435 	bool copro;
436 	u32 reg;
437 
438 	if (!have_input(gpio, offset))
439 		return -ENOTSUPP;
440 
441 	spin_lock_irqsave(&gpio->lock, flags);
442 
443 	reg = ioread32(addr);
444 	reg &= ~GPIO_BIT(offset);
445 
446 	copro = aspeed_gpio_copro_request(gpio, offset);
447 	iowrite32(reg, addr);
448 	if (copro)
449 		aspeed_gpio_copro_release(gpio, offset);
450 
451 	spin_unlock_irqrestore(&gpio->lock, flags);
452 
453 	return 0;
454 }
455 
456 static int aspeed_gpio_dir_out(struct gpio_chip *gc,
457 			       unsigned int offset, int val)
458 {
459 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
460 	const struct aspeed_gpio_bank *bank = to_bank(offset);
461 	void __iomem *addr = bank_reg(gpio, bank, reg_dir);
462 	unsigned long flags;
463 	bool copro;
464 	u32 reg;
465 
466 	if (!have_output(gpio, offset))
467 		return -ENOTSUPP;
468 
469 	spin_lock_irqsave(&gpio->lock, flags);
470 
471 	reg = ioread32(addr);
472 	reg |= GPIO_BIT(offset);
473 
474 	copro = aspeed_gpio_copro_request(gpio, offset);
475 	__aspeed_gpio_set(gc, offset, val);
476 	iowrite32(reg, addr);
477 
478 	if (copro)
479 		aspeed_gpio_copro_release(gpio, offset);
480 	spin_unlock_irqrestore(&gpio->lock, flags);
481 
482 	return 0;
483 }
484 
485 static int aspeed_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
486 {
487 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
488 	const struct aspeed_gpio_bank *bank = to_bank(offset);
489 	unsigned long flags;
490 	u32 val;
491 
492 	if (!have_input(gpio, offset))
493 		return 0;
494 
495 	if (!have_output(gpio, offset))
496 		return 1;
497 
498 	spin_lock_irqsave(&gpio->lock, flags);
499 
500 	val = ioread32(bank_reg(gpio, bank, reg_dir)) & GPIO_BIT(offset);
501 
502 	spin_unlock_irqrestore(&gpio->lock, flags);
503 
504 	return !val;
505 
506 }
507 
508 static inline int irqd_to_aspeed_gpio_data(struct irq_data *d,
509 					   struct aspeed_gpio **gpio,
510 					   const struct aspeed_gpio_bank **bank,
511 					   u32 *bit, int *offset)
512 {
513 	struct aspeed_gpio *internal;
514 
515 	*offset = irqd_to_hwirq(d);
516 
517 	internal = irq_data_get_irq_chip_data(d);
518 
519 	/* This might be a bit of a questionable place to check */
520 	if (!have_irq(internal, *offset))
521 		return -ENOTSUPP;
522 
523 	*gpio = internal;
524 	*bank = to_bank(*offset);
525 	*bit = GPIO_BIT(*offset);
526 
527 	return 0;
528 }
529 
530 static void aspeed_gpio_irq_ack(struct irq_data *d)
531 {
532 	const struct aspeed_gpio_bank *bank;
533 	struct aspeed_gpio *gpio;
534 	unsigned long flags;
535 	void __iomem *status_addr;
536 	int rc, offset;
537 	bool copro;
538 	u32 bit;
539 
540 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit, &offset);
541 	if (rc)
542 		return;
543 
544 	status_addr = bank_reg(gpio, bank, reg_irq_status);
545 
546 	spin_lock_irqsave(&gpio->lock, flags);
547 	copro = aspeed_gpio_copro_request(gpio, offset);
548 
549 	iowrite32(bit, status_addr);
550 
551 	if (copro)
552 		aspeed_gpio_copro_release(gpio, offset);
553 	spin_unlock_irqrestore(&gpio->lock, flags);
554 }
555 
556 static void aspeed_gpio_irq_set_mask(struct irq_data *d, bool set)
557 {
558 	const struct aspeed_gpio_bank *bank;
559 	struct aspeed_gpio *gpio;
560 	unsigned long flags;
561 	u32 reg, bit;
562 	void __iomem *addr;
563 	int rc, offset;
564 	bool copro;
565 
566 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit, &offset);
567 	if (rc)
568 		return;
569 
570 	addr = bank_reg(gpio, bank, reg_irq_enable);
571 
572 	spin_lock_irqsave(&gpio->lock, flags);
573 	copro = aspeed_gpio_copro_request(gpio, offset);
574 
575 	reg = ioread32(addr);
576 	if (set)
577 		reg |= bit;
578 	else
579 		reg &= ~bit;
580 	iowrite32(reg, addr);
581 
582 	if (copro)
583 		aspeed_gpio_copro_release(gpio, offset);
584 	spin_unlock_irqrestore(&gpio->lock, flags);
585 }
586 
587 static void aspeed_gpio_irq_mask(struct irq_data *d)
588 {
589 	aspeed_gpio_irq_set_mask(d, false);
590 }
591 
592 static void aspeed_gpio_irq_unmask(struct irq_data *d)
593 {
594 	aspeed_gpio_irq_set_mask(d, true);
595 }
596 
597 static int aspeed_gpio_set_type(struct irq_data *d, unsigned int type)
598 {
599 	u32 type0 = 0;
600 	u32 type1 = 0;
601 	u32 type2 = 0;
602 	u32 bit, reg;
603 	const struct aspeed_gpio_bank *bank;
604 	irq_flow_handler_t handler;
605 	struct aspeed_gpio *gpio;
606 	unsigned long flags;
607 	void __iomem *addr;
608 	int rc, offset;
609 	bool copro;
610 
611 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit, &offset);
612 	if (rc)
613 		return -EINVAL;
614 
615 	switch (type & IRQ_TYPE_SENSE_MASK) {
616 	case IRQ_TYPE_EDGE_BOTH:
617 		type2 |= bit;
618 		/* fall through */
619 	case IRQ_TYPE_EDGE_RISING:
620 		type0 |= bit;
621 		/* fall through */
622 	case IRQ_TYPE_EDGE_FALLING:
623 		handler = handle_edge_irq;
624 		break;
625 	case IRQ_TYPE_LEVEL_HIGH:
626 		type0 |= bit;
627 		/* fall through */
628 	case IRQ_TYPE_LEVEL_LOW:
629 		type1 |= bit;
630 		handler = handle_level_irq;
631 		break;
632 	default:
633 		return -EINVAL;
634 	}
635 
636 	spin_lock_irqsave(&gpio->lock, flags);
637 	copro = aspeed_gpio_copro_request(gpio, offset);
638 
639 	addr = bank_reg(gpio, bank, reg_irq_type0);
640 	reg = ioread32(addr);
641 	reg = (reg & ~bit) | type0;
642 	iowrite32(reg, addr);
643 
644 	addr = bank_reg(gpio, bank, reg_irq_type1);
645 	reg = ioread32(addr);
646 	reg = (reg & ~bit) | type1;
647 	iowrite32(reg, addr);
648 
649 	addr = bank_reg(gpio, bank, reg_irq_type2);
650 	reg = ioread32(addr);
651 	reg = (reg & ~bit) | type2;
652 	iowrite32(reg, addr);
653 
654 	if (copro)
655 		aspeed_gpio_copro_release(gpio, offset);
656 	spin_unlock_irqrestore(&gpio->lock, flags);
657 
658 	irq_set_handler_locked(d, handler);
659 
660 	return 0;
661 }
662 
663 static void aspeed_gpio_irq_handler(struct irq_desc *desc)
664 {
665 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
666 	struct irq_chip *ic = irq_desc_get_chip(desc);
667 	struct aspeed_gpio *data = gpiochip_get_data(gc);
668 	unsigned int i, p, girq;
669 	unsigned long reg;
670 
671 	chained_irq_enter(ic, desc);
672 
673 	for (i = 0; i < ARRAY_SIZE(aspeed_gpio_banks); i++) {
674 		const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i];
675 
676 		reg = ioread32(bank_reg(data, bank, reg_irq_status));
677 
678 		for_each_set_bit(p, &reg, 32) {
679 			girq = irq_find_mapping(gc->irq.domain, i * 32 + p);
680 			generic_handle_irq(girq);
681 		}
682 
683 	}
684 
685 	chained_irq_exit(ic, desc);
686 }
687 
688 static struct irq_chip aspeed_gpio_irqchip = {
689 	.name		= "aspeed-gpio",
690 	.irq_ack	= aspeed_gpio_irq_ack,
691 	.irq_mask	= aspeed_gpio_irq_mask,
692 	.irq_unmask	= aspeed_gpio_irq_unmask,
693 	.irq_set_type	= aspeed_gpio_set_type,
694 };
695 
696 static void set_irq_valid_mask(struct aspeed_gpio *gpio)
697 {
698 	const struct aspeed_bank_props *props = gpio->config->props;
699 
700 	while (!is_bank_props_sentinel(props)) {
701 		unsigned int offset;
702 		const unsigned long int input = props->input;
703 
704 		/* Pretty crummy approach, but similar to GPIO core */
705 		for_each_clear_bit(offset, &input, 32) {
706 			unsigned int i = props->bank * 32 + offset;
707 
708 			if (i >= gpio->config->nr_gpios)
709 				break;
710 
711 			clear_bit(i, gpio->chip.irq.valid_mask);
712 		}
713 
714 		props++;
715 	}
716 }
717 
718 static int aspeed_gpio_setup_irqs(struct aspeed_gpio *gpio,
719 		struct platform_device *pdev)
720 {
721 	int rc;
722 
723 	rc = platform_get_irq(pdev, 0);
724 	if (rc < 0)
725 		return rc;
726 
727 	gpio->irq = rc;
728 
729 	set_irq_valid_mask(gpio);
730 
731 	rc = gpiochip_irqchip_add(&gpio->chip, &aspeed_gpio_irqchip,
732 			0, handle_bad_irq, IRQ_TYPE_NONE);
733 	if (rc) {
734 		dev_info(&pdev->dev, "Could not add irqchip\n");
735 		return rc;
736 	}
737 
738 	gpiochip_set_chained_irqchip(&gpio->chip, &aspeed_gpio_irqchip,
739 				     gpio->irq, aspeed_gpio_irq_handler);
740 
741 	return 0;
742 }
743 
744 static int aspeed_gpio_reset_tolerance(struct gpio_chip *chip,
745 					unsigned int offset, bool enable)
746 {
747 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
748 	unsigned long flags;
749 	void __iomem *treg;
750 	bool copro;
751 	u32 val;
752 
753 	treg = bank_reg(gpio, to_bank(offset), reg_tolerance);
754 
755 	spin_lock_irqsave(&gpio->lock, flags);
756 	copro = aspeed_gpio_copro_request(gpio, offset);
757 
758 	val = readl(treg);
759 
760 	if (enable)
761 		val |= GPIO_BIT(offset);
762 	else
763 		val &= ~GPIO_BIT(offset);
764 
765 	writel(val, treg);
766 
767 	if (copro)
768 		aspeed_gpio_copro_release(gpio, offset);
769 	spin_unlock_irqrestore(&gpio->lock, flags);
770 
771 	return 0;
772 }
773 
774 static int aspeed_gpio_request(struct gpio_chip *chip, unsigned int offset)
775 {
776 	if (!have_gpio(gpiochip_get_data(chip), offset))
777 		return -ENODEV;
778 
779 	return pinctrl_gpio_request(chip->base + offset);
780 }
781 
782 static void aspeed_gpio_free(struct gpio_chip *chip, unsigned int offset)
783 {
784 	pinctrl_gpio_free(chip->base + offset);
785 }
786 
787 static int usecs_to_cycles(struct aspeed_gpio *gpio, unsigned long usecs,
788 		u32 *cycles)
789 {
790 	u64 rate;
791 	u64 n;
792 	u32 r;
793 
794 	rate = clk_get_rate(gpio->clk);
795 	if (!rate)
796 		return -ENOTSUPP;
797 
798 	n = rate * usecs;
799 	r = do_div(n, 1000000);
800 
801 	if (n >= U32_MAX)
802 		return -ERANGE;
803 
804 	/* At least as long as the requested time */
805 	*cycles = n + (!!r);
806 
807 	return 0;
808 }
809 
810 /* Call under gpio->lock */
811 static int register_allocated_timer(struct aspeed_gpio *gpio,
812 		unsigned int offset, unsigned int timer)
813 {
814 	if (WARN(gpio->offset_timer[offset] != 0,
815 				"Offset %d already allocated timer %d\n",
816 				offset, gpio->offset_timer[offset]))
817 		return -EINVAL;
818 
819 	if (WARN(gpio->timer_users[timer] == UINT_MAX,
820 				"Timer user count would overflow\n"))
821 		return -EPERM;
822 
823 	gpio->offset_timer[offset] = timer;
824 	gpio->timer_users[timer]++;
825 
826 	return 0;
827 }
828 
829 /* Call under gpio->lock */
830 static int unregister_allocated_timer(struct aspeed_gpio *gpio,
831 		unsigned int offset)
832 {
833 	if (WARN(gpio->offset_timer[offset] == 0,
834 				"No timer allocated to offset %d\n", offset))
835 		return -EINVAL;
836 
837 	if (WARN(gpio->timer_users[gpio->offset_timer[offset]] == 0,
838 				"No users recorded for timer %d\n",
839 				gpio->offset_timer[offset]))
840 		return -EINVAL;
841 
842 	gpio->timer_users[gpio->offset_timer[offset]]--;
843 	gpio->offset_timer[offset] = 0;
844 
845 	return 0;
846 }
847 
848 /* Call under gpio->lock */
849 static inline bool timer_allocation_registered(struct aspeed_gpio *gpio,
850 		unsigned int offset)
851 {
852 	return gpio->offset_timer[offset] > 0;
853 }
854 
855 /* Call under gpio->lock */
856 static void configure_timer(struct aspeed_gpio *gpio, unsigned int offset,
857 		unsigned int timer)
858 {
859 	const struct aspeed_gpio_bank *bank = to_bank(offset);
860 	const u32 mask = GPIO_BIT(offset);
861 	void __iomem *addr;
862 	u32 val;
863 
864 	/* Note: Debounce timer isn't under control of the command
865 	 * source registers, so no need to sync with the coprocessor
866 	 */
867 	addr = bank_reg(gpio, bank, reg_debounce_sel1);
868 	val = ioread32(addr);
869 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE1(timer, offset), addr);
870 
871 	addr = bank_reg(gpio, bank, reg_debounce_sel2);
872 	val = ioread32(addr);
873 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE2(timer, offset), addr);
874 }
875 
876 static int enable_debounce(struct gpio_chip *chip, unsigned int offset,
877 				    unsigned long usecs)
878 {
879 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
880 	u32 requested_cycles;
881 	unsigned long flags;
882 	int rc;
883 	int i;
884 
885 	if (!gpio->clk)
886 		return -EINVAL;
887 
888 	rc = usecs_to_cycles(gpio, usecs, &requested_cycles);
889 	if (rc < 0) {
890 		dev_warn(chip->parent, "Failed to convert %luus to cycles at %luHz: %d\n",
891 				usecs, clk_get_rate(gpio->clk), rc);
892 		return rc;
893 	}
894 
895 	spin_lock_irqsave(&gpio->lock, flags);
896 
897 	if (timer_allocation_registered(gpio, offset)) {
898 		rc = unregister_allocated_timer(gpio, offset);
899 		if (rc < 0)
900 			goto out;
901 	}
902 
903 	/* Try to find a timer already configured for the debounce period */
904 	for (i = 1; i < ARRAY_SIZE(debounce_timers); i++) {
905 		u32 cycles;
906 
907 		cycles = ioread32(gpio->base + debounce_timers[i]);
908 		if (requested_cycles == cycles)
909 			break;
910 	}
911 
912 	if (i == ARRAY_SIZE(debounce_timers)) {
913 		int j;
914 
915 		/*
916 		 * As there are no timers configured for the requested debounce
917 		 * period, find an unused timer instead
918 		 */
919 		for (j = 1; j < ARRAY_SIZE(gpio->timer_users); j++) {
920 			if (gpio->timer_users[j] == 0)
921 				break;
922 		}
923 
924 		if (j == ARRAY_SIZE(gpio->timer_users)) {
925 			dev_warn(chip->parent,
926 					"Debounce timers exhausted, cannot debounce for period %luus\n",
927 					usecs);
928 
929 			rc = -EPERM;
930 
931 			/*
932 			 * We already adjusted the accounting to remove @offset
933 			 * as a user of its previous timer, so also configure
934 			 * the hardware so @offset has timers disabled for
935 			 * consistency.
936 			 */
937 			configure_timer(gpio, offset, 0);
938 			goto out;
939 		}
940 
941 		i = j;
942 
943 		iowrite32(requested_cycles, gpio->base + debounce_timers[i]);
944 	}
945 
946 	if (WARN(i == 0, "Cannot register index of disabled timer\n")) {
947 		rc = -EINVAL;
948 		goto out;
949 	}
950 
951 	register_allocated_timer(gpio, offset, i);
952 	configure_timer(gpio, offset, i);
953 
954 out:
955 	spin_unlock_irqrestore(&gpio->lock, flags);
956 
957 	return rc;
958 }
959 
960 static int disable_debounce(struct gpio_chip *chip, unsigned int offset)
961 {
962 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
963 	unsigned long flags;
964 	int rc;
965 
966 	spin_lock_irqsave(&gpio->lock, flags);
967 
968 	rc = unregister_allocated_timer(gpio, offset);
969 	if (!rc)
970 		configure_timer(gpio, offset, 0);
971 
972 	spin_unlock_irqrestore(&gpio->lock, flags);
973 
974 	return rc;
975 }
976 
977 static int set_debounce(struct gpio_chip *chip, unsigned int offset,
978 				    unsigned long usecs)
979 {
980 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
981 
982 	if (!have_debounce(gpio, offset))
983 		return -ENOTSUPP;
984 
985 	if (usecs)
986 		return enable_debounce(chip, offset, usecs);
987 
988 	return disable_debounce(chip, offset);
989 }
990 
991 static int aspeed_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
992 				  unsigned long config)
993 {
994 	unsigned long param = pinconf_to_config_param(config);
995 	u32 arg = pinconf_to_config_argument(config);
996 
997 	if (param == PIN_CONFIG_INPUT_DEBOUNCE)
998 		return set_debounce(chip, offset, arg);
999 	else if (param == PIN_CONFIG_BIAS_DISABLE ||
1000 			param == PIN_CONFIG_BIAS_PULL_DOWN ||
1001 			param == PIN_CONFIG_DRIVE_STRENGTH)
1002 		return pinctrl_gpio_set_config(offset, config);
1003 	else if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN ||
1004 			param == PIN_CONFIG_DRIVE_OPEN_SOURCE)
1005 		/* Return -ENOTSUPP to trigger emulation, as per datasheet */
1006 		return -ENOTSUPP;
1007 	else if (param == PIN_CONFIG_PERSIST_STATE)
1008 		return aspeed_gpio_reset_tolerance(chip, offset, arg);
1009 
1010 	return -ENOTSUPP;
1011 }
1012 
1013 /**
1014  * aspeed_gpio_copro_set_ops - Sets the callbacks used for handhsaking with
1015  *                             the coprocessor for shared GPIO banks
1016  * @ops: The callbacks
1017  * @data: Pointer passed back to the callbacks
1018  */
1019 int aspeed_gpio_copro_set_ops(const struct aspeed_gpio_copro_ops *ops, void *data)
1020 {
1021 	copro_data = data;
1022 	copro_ops = ops;
1023 
1024 	return 0;
1025 }
1026 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_set_ops);
1027 
1028 /**
1029  * aspeed_gpio_copro_grab_gpio - Mark a GPIO used by the coprocessor. The entire
1030  *                               bank gets marked and any access from the ARM will
1031  *                               result in handshaking via callbacks.
1032  * @desc: The GPIO to be marked
1033  * @vreg_offset: If non-NULL, returns the value register offset in the GPIO space
1034  * @dreg_offset: If non-NULL, returns the data latch register offset in the GPIO space
1035  * @bit: If non-NULL, returns the bit number of the GPIO in the registers
1036  */
1037 int aspeed_gpio_copro_grab_gpio(struct gpio_desc *desc,
1038 				u16 *vreg_offset, u16 *dreg_offset, u8 *bit)
1039 {
1040 	struct gpio_chip *chip = gpiod_to_chip(desc);
1041 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
1042 	int rc = 0, bindex, offset = gpio_chip_hwgpio(desc);
1043 	const struct aspeed_gpio_bank *bank = to_bank(offset);
1044 	unsigned long flags;
1045 
1046 	if (!gpio->cf_copro_bankmap)
1047 		gpio->cf_copro_bankmap = kzalloc(gpio->config->nr_gpios >> 3, GFP_KERNEL);
1048 	if (!gpio->cf_copro_bankmap)
1049 		return -ENOMEM;
1050 	if (offset < 0 || offset > gpio->config->nr_gpios)
1051 		return -EINVAL;
1052 	bindex = offset >> 3;
1053 
1054 	spin_lock_irqsave(&gpio->lock, flags);
1055 
1056 	/* Sanity check, this shouldn't happen */
1057 	if (gpio->cf_copro_bankmap[bindex] == 0xff) {
1058 		rc = -EIO;
1059 		goto bail;
1060 	}
1061 	gpio->cf_copro_bankmap[bindex]++;
1062 
1063 	/* Switch command source */
1064 	if (gpio->cf_copro_bankmap[bindex] == 1)
1065 		aspeed_gpio_change_cmd_source(gpio, bank, bindex,
1066 					      GPIO_CMDSRC_COLDFIRE);
1067 
1068 	if (vreg_offset)
1069 		*vreg_offset = bank->val_regs;
1070 	if (dreg_offset)
1071 		*dreg_offset = bank->rdata_reg;
1072 	if (bit)
1073 		*bit = GPIO_OFFSET(offset);
1074  bail:
1075 	spin_unlock_irqrestore(&gpio->lock, flags);
1076 	return rc;
1077 }
1078 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_grab_gpio);
1079 
1080 /**
1081  * aspeed_gpio_copro_release_gpio - Unmark a GPIO used by the coprocessor.
1082  * @desc: The GPIO to be marked
1083  */
1084 int aspeed_gpio_copro_release_gpio(struct gpio_desc *desc)
1085 {
1086 	struct gpio_chip *chip = gpiod_to_chip(desc);
1087 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
1088 	int rc = 0, bindex, offset = gpio_chip_hwgpio(desc);
1089 	const struct aspeed_gpio_bank *bank = to_bank(offset);
1090 	unsigned long flags;
1091 
1092 	if (!gpio->cf_copro_bankmap)
1093 		return -ENXIO;
1094 
1095 	if (offset < 0 || offset > gpio->config->nr_gpios)
1096 		return -EINVAL;
1097 	bindex = offset >> 3;
1098 
1099 	spin_lock_irqsave(&gpio->lock, flags);
1100 
1101 	/* Sanity check, this shouldn't happen */
1102 	if (gpio->cf_copro_bankmap[bindex] == 0) {
1103 		rc = -EIO;
1104 		goto bail;
1105 	}
1106 	gpio->cf_copro_bankmap[bindex]--;
1107 
1108 	/* Switch command source */
1109 	if (gpio->cf_copro_bankmap[bindex] == 0)
1110 		aspeed_gpio_change_cmd_source(gpio, bank, bindex,
1111 					      GPIO_CMDSRC_ARM);
1112  bail:
1113 	spin_unlock_irqrestore(&gpio->lock, flags);
1114 	return rc;
1115 }
1116 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_release_gpio);
1117 
1118 /*
1119  * Any banks not specified in a struct aspeed_bank_props array are assumed to
1120  * have the properties:
1121  *
1122  *     { .input = 0xffffffff, .output = 0xffffffff }
1123  */
1124 
1125 static const struct aspeed_bank_props ast2400_bank_props[] = {
1126 	/*     input	  output   */
1127 	{ 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
1128 	{ 6, 0x0000000f, 0x0fffff0f }, /* Y/Z/AA/AB, two 4-GPIO holes */
1129 	{ },
1130 };
1131 
1132 static const struct aspeed_gpio_config ast2400_config =
1133 	/* 220 for simplicity, really 216 with two 4-GPIO holes, four at end */
1134 	{ .nr_gpios = 220, .props = ast2400_bank_props, };
1135 
1136 static const struct aspeed_bank_props ast2500_bank_props[] = {
1137 	/*     input	  output   */
1138 	{ 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
1139 	{ 6, 0x0fffffff, 0x0fffffff }, /* Y/Z/AA/AB, 4-GPIO hole */
1140 	{ 7, 0x000000ff, 0x000000ff }, /* AC */
1141 	{ },
1142 };
1143 
1144 static const struct aspeed_gpio_config ast2500_config =
1145 	/* 232 for simplicity, actual number is 228 (4-GPIO hole in GPIOAB) */
1146 	{ .nr_gpios = 232, .props = ast2500_bank_props, };
1147 
1148 static const struct of_device_id aspeed_gpio_of_table[] = {
1149 	{ .compatible = "aspeed,ast2400-gpio", .data = &ast2400_config, },
1150 	{ .compatible = "aspeed,ast2500-gpio", .data = &ast2500_config, },
1151 	{}
1152 };
1153 MODULE_DEVICE_TABLE(of, aspeed_gpio_of_table);
1154 
1155 static int __init aspeed_gpio_probe(struct platform_device *pdev)
1156 {
1157 	const struct of_device_id *gpio_id;
1158 	struct aspeed_gpio *gpio;
1159 	struct resource *res;
1160 	int rc, i, banks;
1161 
1162 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
1163 	if (!gpio)
1164 		return -ENOMEM;
1165 
1166 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1167 	gpio->base = devm_ioremap_resource(&pdev->dev, res);
1168 	if (IS_ERR(gpio->base))
1169 		return PTR_ERR(gpio->base);
1170 
1171 	spin_lock_init(&gpio->lock);
1172 
1173 	gpio_id = of_match_node(aspeed_gpio_of_table, pdev->dev.of_node);
1174 	if (!gpio_id)
1175 		return -EINVAL;
1176 
1177 	gpio->clk = of_clk_get(pdev->dev.of_node, 0);
1178 	if (IS_ERR(gpio->clk)) {
1179 		dev_warn(&pdev->dev,
1180 				"Failed to get clock from devicetree, debouncing disabled\n");
1181 		gpio->clk = NULL;
1182 	}
1183 
1184 	gpio->config = gpio_id->data;
1185 
1186 	gpio->chip.parent = &pdev->dev;
1187 	gpio->chip.ngpio = gpio->config->nr_gpios;
1188 	gpio->chip.direction_input = aspeed_gpio_dir_in;
1189 	gpio->chip.direction_output = aspeed_gpio_dir_out;
1190 	gpio->chip.get_direction = aspeed_gpio_get_direction;
1191 	gpio->chip.request = aspeed_gpio_request;
1192 	gpio->chip.free = aspeed_gpio_free;
1193 	gpio->chip.get = aspeed_gpio_get;
1194 	gpio->chip.set = aspeed_gpio_set;
1195 	gpio->chip.set_config = aspeed_gpio_set_config;
1196 	gpio->chip.label = dev_name(&pdev->dev);
1197 	gpio->chip.base = -1;
1198 	gpio->chip.irq.need_valid_mask = true;
1199 
1200 	/* Allocate a cache of the output registers */
1201 	banks = gpio->config->nr_gpios >> 5;
1202 	gpio->dcache = devm_kcalloc(&pdev->dev,
1203 				    banks, sizeof(u32), GFP_KERNEL);
1204 	if (!gpio->dcache)
1205 		return -ENOMEM;
1206 
1207 	/*
1208 	 * Populate it with initial values read from the HW and switch
1209 	 * all command sources to the ARM by default
1210 	 */
1211 	for (i = 0; i < banks; i++) {
1212 		const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i];
1213 		void __iomem *addr = bank_reg(gpio, bank, reg_rdata);
1214 		gpio->dcache[i] = ioread32(addr);
1215 		aspeed_gpio_change_cmd_source(gpio, bank, 0, GPIO_CMDSRC_ARM);
1216 		aspeed_gpio_change_cmd_source(gpio, bank, 1, GPIO_CMDSRC_ARM);
1217 		aspeed_gpio_change_cmd_source(gpio, bank, 2, GPIO_CMDSRC_ARM);
1218 		aspeed_gpio_change_cmd_source(gpio, bank, 3, GPIO_CMDSRC_ARM);
1219 	}
1220 
1221 	rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
1222 	if (rc < 0)
1223 		return rc;
1224 
1225 	gpio->offset_timer =
1226 		devm_kzalloc(&pdev->dev, gpio->chip.ngpio, GFP_KERNEL);
1227 
1228 	return aspeed_gpio_setup_irqs(gpio, pdev);
1229 }
1230 
1231 static struct platform_driver aspeed_gpio_driver = {
1232 	.driver = {
1233 		.name = KBUILD_MODNAME,
1234 		.of_match_table = aspeed_gpio_of_table,
1235 	},
1236 };
1237 
1238 module_platform_driver_probe(aspeed_gpio_driver, aspeed_gpio_probe);
1239 
1240 MODULE_DESCRIPTION("Aspeed GPIO Driver");
1241 MODULE_LICENSE("GPL");
1242