xref: /openbmc/linux/drivers/gpio/gpio-aspeed.c (revision 8dce88fe)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2015 IBM Corp.
4  *
5  * Joel Stanley <joel@jms.id.au>
6  */
7 
8 #include <asm/div64.h>
9 #include <linux/clk.h>
10 #include <linux/gpio/driver.h>
11 #include <linux/gpio/aspeed.h>
12 #include <linux/hashtable.h>
13 #include <linux/init.h>
14 #include <linux/io.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/pinctrl/consumer.h>
18 #include <linux/platform_device.h>
19 #include <linux/spinlock.h>
20 #include <linux/string.h>
21 
22 /*
23  * These two headers aren't meant to be used by GPIO drivers. We need
24  * them in order to access gpio_chip_hwgpio() which we need to implement
25  * the aspeed specific API which allows the coprocessor to request
26  * access to some GPIOs and to arbitrate between coprocessor and ARM.
27  */
28 #include <linux/gpio/consumer.h>
29 #include "gpiolib.h"
30 
31 struct aspeed_bank_props {
32 	unsigned int bank;
33 	u32 input;
34 	u32 output;
35 };
36 
37 struct aspeed_gpio_config {
38 	unsigned int nr_gpios;
39 	const struct aspeed_bank_props *props;
40 };
41 
42 /*
43  * @offset_timer: Maps an offset to an @timer_users index, or zero if disabled
44  * @timer_users: Tracks the number of users for each timer
45  *
46  * The @timer_users has four elements but the first element is unused. This is
47  * to simplify accounting and indexing, as a zero value in @offset_timer
48  * represents disabled debouncing for the GPIO. Any other value for an element
49  * of @offset_timer is used as an index into @timer_users. This behaviour of
50  * the zero value aligns with the behaviour of zero built from the timer
51  * configuration registers (i.e. debouncing is disabled).
52  */
53 struct aspeed_gpio {
54 	struct gpio_chip chip;
55 	struct irq_chip irqc;
56 	spinlock_t lock;
57 	void __iomem *base;
58 	int irq;
59 	const struct aspeed_gpio_config *config;
60 
61 	u8 *offset_timer;
62 	unsigned int timer_users[4];
63 	struct clk *clk;
64 
65 	u32 *dcache;
66 	u8 *cf_copro_bankmap;
67 };
68 
69 struct aspeed_gpio_bank {
70 	uint16_t	val_regs;	/* +0: Rd: read input value, Wr: set write latch
71 					 * +4: Rd/Wr: Direction (0=in, 1=out)
72 					 */
73 	uint16_t	rdata_reg;	/*     Rd: read write latch, Wr: <none>  */
74 	uint16_t	irq_regs;
75 	uint16_t	debounce_regs;
76 	uint16_t	tolerance_regs;
77 	uint16_t	cmdsrc_regs;
78 	const char	names[4][3];
79 };
80 
81 /*
82  * Note: The "value" register returns the input value sampled on the
83  *       line even when the GPIO is configured as an output. Since
84  *       that input goes through synchronizers, writing, then reading
85  *       back may not return the written value right away.
86  *
87  *       The "rdata" register returns the content of the write latch
88  *       and thus can be used to read back what was last written
89  *       reliably.
90  */
91 
92 static const int debounce_timers[4] = { 0x00, 0x50, 0x54, 0x58 };
93 
94 static const struct aspeed_gpio_copro_ops *copro_ops;
95 static void *copro_data;
96 
97 static const struct aspeed_gpio_bank aspeed_gpio_banks[] = {
98 	{
99 		.val_regs = 0x0000,
100 		.rdata_reg = 0x00c0,
101 		.irq_regs = 0x0008,
102 		.debounce_regs = 0x0040,
103 		.tolerance_regs = 0x001c,
104 		.cmdsrc_regs = 0x0060,
105 		.names = { "A", "B", "C", "D" },
106 	},
107 	{
108 		.val_regs = 0x0020,
109 		.rdata_reg = 0x00c4,
110 		.irq_regs = 0x0028,
111 		.debounce_regs = 0x0048,
112 		.tolerance_regs = 0x003c,
113 		.cmdsrc_regs = 0x0068,
114 		.names = { "E", "F", "G", "H" },
115 	},
116 	{
117 		.val_regs = 0x0070,
118 		.rdata_reg = 0x00c8,
119 		.irq_regs = 0x0098,
120 		.debounce_regs = 0x00b0,
121 		.tolerance_regs = 0x00ac,
122 		.cmdsrc_regs = 0x0090,
123 		.names = { "I", "J", "K", "L" },
124 	},
125 	{
126 		.val_regs = 0x0078,
127 		.rdata_reg = 0x00cc,
128 		.irq_regs = 0x00e8,
129 		.debounce_regs = 0x0100,
130 		.tolerance_regs = 0x00fc,
131 		.cmdsrc_regs = 0x00e0,
132 		.names = { "M", "N", "O", "P" },
133 	},
134 	{
135 		.val_regs = 0x0080,
136 		.rdata_reg = 0x00d0,
137 		.irq_regs = 0x0118,
138 		.debounce_regs = 0x0130,
139 		.tolerance_regs = 0x012c,
140 		.cmdsrc_regs = 0x0110,
141 		.names = { "Q", "R", "S", "T" },
142 	},
143 	{
144 		.val_regs = 0x0088,
145 		.rdata_reg = 0x00d4,
146 		.irq_regs = 0x0148,
147 		.debounce_regs = 0x0160,
148 		.tolerance_regs = 0x015c,
149 		.cmdsrc_regs = 0x0140,
150 		.names = { "U", "V", "W", "X" },
151 	},
152 	{
153 		.val_regs = 0x01E0,
154 		.rdata_reg = 0x00d8,
155 		.irq_regs = 0x0178,
156 		.debounce_regs = 0x0190,
157 		.tolerance_regs = 0x018c,
158 		.cmdsrc_regs = 0x0170,
159 		.names = { "Y", "Z", "AA", "AB" },
160 	},
161 	{
162 		.val_regs = 0x01e8,
163 		.rdata_reg = 0x00dc,
164 		.irq_regs = 0x01a8,
165 		.debounce_regs = 0x01c0,
166 		.tolerance_regs = 0x01bc,
167 		.cmdsrc_regs = 0x01a0,
168 		.names = { "AC", "", "", "" },
169 	},
170 };
171 
172 enum aspeed_gpio_reg {
173 	reg_val,
174 	reg_rdata,
175 	reg_dir,
176 	reg_irq_enable,
177 	reg_irq_type0,
178 	reg_irq_type1,
179 	reg_irq_type2,
180 	reg_irq_status,
181 	reg_debounce_sel1,
182 	reg_debounce_sel2,
183 	reg_tolerance,
184 	reg_cmdsrc0,
185 	reg_cmdsrc1,
186 };
187 
188 #define GPIO_VAL_VALUE	0x00
189 #define GPIO_VAL_DIR	0x04
190 
191 #define GPIO_IRQ_ENABLE	0x00
192 #define GPIO_IRQ_TYPE0	0x04
193 #define GPIO_IRQ_TYPE1	0x08
194 #define GPIO_IRQ_TYPE2	0x0c
195 #define GPIO_IRQ_STATUS	0x10
196 
197 #define GPIO_DEBOUNCE_SEL1 0x00
198 #define GPIO_DEBOUNCE_SEL2 0x04
199 
200 #define GPIO_CMDSRC_0	0x00
201 #define GPIO_CMDSRC_1	0x04
202 #define  GPIO_CMDSRC_ARM		0
203 #define  GPIO_CMDSRC_LPC		1
204 #define  GPIO_CMDSRC_COLDFIRE		2
205 #define  GPIO_CMDSRC_RESERVED		3
206 
207 /* This will be resolved at compile time */
208 static inline void __iomem *bank_reg(struct aspeed_gpio *gpio,
209 				     const struct aspeed_gpio_bank *bank,
210 				     const enum aspeed_gpio_reg reg)
211 {
212 	switch (reg) {
213 	case reg_val:
214 		return gpio->base + bank->val_regs + GPIO_VAL_VALUE;
215 	case reg_rdata:
216 		return gpio->base + bank->rdata_reg;
217 	case reg_dir:
218 		return gpio->base + bank->val_regs + GPIO_VAL_DIR;
219 	case reg_irq_enable:
220 		return gpio->base + bank->irq_regs + GPIO_IRQ_ENABLE;
221 	case reg_irq_type0:
222 		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE0;
223 	case reg_irq_type1:
224 		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE1;
225 	case reg_irq_type2:
226 		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE2;
227 	case reg_irq_status:
228 		return gpio->base + bank->irq_regs + GPIO_IRQ_STATUS;
229 	case reg_debounce_sel1:
230 		return gpio->base + bank->debounce_regs + GPIO_DEBOUNCE_SEL1;
231 	case reg_debounce_sel2:
232 		return gpio->base + bank->debounce_regs + GPIO_DEBOUNCE_SEL2;
233 	case reg_tolerance:
234 		return gpio->base + bank->tolerance_regs;
235 	case reg_cmdsrc0:
236 		return gpio->base + bank->cmdsrc_regs + GPIO_CMDSRC_0;
237 	case reg_cmdsrc1:
238 		return gpio->base + bank->cmdsrc_regs + GPIO_CMDSRC_1;
239 	}
240 	BUG();
241 }
242 
243 #define GPIO_BANK(x)	((x) >> 5)
244 #define GPIO_OFFSET(x)	((x) & 0x1f)
245 #define GPIO_BIT(x)	BIT(GPIO_OFFSET(x))
246 
247 #define _GPIO_SET_DEBOUNCE(t, o, i) ((!!((t) & BIT(i))) << GPIO_OFFSET(o))
248 #define GPIO_SET_DEBOUNCE1(t, o) _GPIO_SET_DEBOUNCE(t, o, 1)
249 #define GPIO_SET_DEBOUNCE2(t, o) _GPIO_SET_DEBOUNCE(t, o, 0)
250 
251 static const struct aspeed_gpio_bank *to_bank(unsigned int offset)
252 {
253 	unsigned int bank = GPIO_BANK(offset);
254 
255 	WARN_ON(bank >= ARRAY_SIZE(aspeed_gpio_banks));
256 	return &aspeed_gpio_banks[bank];
257 }
258 
259 static inline bool is_bank_props_sentinel(const struct aspeed_bank_props *props)
260 {
261 	return !(props->input || props->output);
262 }
263 
264 static inline const struct aspeed_bank_props *find_bank_props(
265 		struct aspeed_gpio *gpio, unsigned int offset)
266 {
267 	const struct aspeed_bank_props *props = gpio->config->props;
268 
269 	while (!is_bank_props_sentinel(props)) {
270 		if (props->bank == GPIO_BANK(offset))
271 			return props;
272 		props++;
273 	}
274 
275 	return NULL;
276 }
277 
278 static inline bool have_gpio(struct aspeed_gpio *gpio, unsigned int offset)
279 {
280 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
281 	const struct aspeed_gpio_bank *bank = to_bank(offset);
282 	unsigned int group = GPIO_OFFSET(offset) / 8;
283 
284 	return bank->names[group][0] != '\0' &&
285 		(!props || ((props->input | props->output) & GPIO_BIT(offset)));
286 }
287 
288 static inline bool have_input(struct aspeed_gpio *gpio, unsigned int offset)
289 {
290 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
291 
292 	return !props || (props->input & GPIO_BIT(offset));
293 }
294 
295 #define have_irq(g, o) have_input((g), (o))
296 #define have_debounce(g, o) have_input((g), (o))
297 
298 static inline bool have_output(struct aspeed_gpio *gpio, unsigned int offset)
299 {
300 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
301 
302 	return !props || (props->output & GPIO_BIT(offset));
303 }
304 
305 static void aspeed_gpio_change_cmd_source(struct aspeed_gpio *gpio,
306 					  const struct aspeed_gpio_bank *bank,
307 					  int bindex, int cmdsrc)
308 {
309 	void __iomem *c0 = bank_reg(gpio, bank, reg_cmdsrc0);
310 	void __iomem *c1 = bank_reg(gpio, bank, reg_cmdsrc1);
311 	u32 bit, reg;
312 
313 	/*
314 	 * Each register controls 4 banks, so take the bottom 2
315 	 * bits of the bank index, and use them to select the
316 	 * right control bit (0, 8, 16 or 24).
317 	 */
318 	bit = BIT((bindex & 3) << 3);
319 
320 	/* Source 1 first to avoid illegal 11 combination */
321 	reg = ioread32(c1);
322 	if (cmdsrc & 2)
323 		reg |= bit;
324 	else
325 		reg &= ~bit;
326 	iowrite32(reg, c1);
327 
328 	/* Then Source 0 */
329 	reg = ioread32(c0);
330 	if (cmdsrc & 1)
331 		reg |= bit;
332 	else
333 		reg &= ~bit;
334 	iowrite32(reg, c0);
335 }
336 
337 static bool aspeed_gpio_copro_request(struct aspeed_gpio *gpio,
338 				      unsigned int offset)
339 {
340 	const struct aspeed_gpio_bank *bank = to_bank(offset);
341 
342 	if (!copro_ops || !gpio->cf_copro_bankmap)
343 		return false;
344 	if (!gpio->cf_copro_bankmap[offset >> 3])
345 		return false;
346 	if (!copro_ops->request_access)
347 		return false;
348 
349 	/* Pause the coprocessor */
350 	copro_ops->request_access(copro_data);
351 
352 	/* Change command source back to ARM */
353 	aspeed_gpio_change_cmd_source(gpio, bank, offset >> 3, GPIO_CMDSRC_ARM);
354 
355 	/* Update cache */
356 	gpio->dcache[GPIO_BANK(offset)] = ioread32(bank_reg(gpio, bank, reg_rdata));
357 
358 	return true;
359 }
360 
361 static void aspeed_gpio_copro_release(struct aspeed_gpio *gpio,
362 				      unsigned int offset)
363 {
364 	const struct aspeed_gpio_bank *bank = to_bank(offset);
365 
366 	if (!copro_ops || !gpio->cf_copro_bankmap)
367 		return;
368 	if (!gpio->cf_copro_bankmap[offset >> 3])
369 		return;
370 	if (!copro_ops->release_access)
371 		return;
372 
373 	/* Change command source back to ColdFire */
374 	aspeed_gpio_change_cmd_source(gpio, bank, offset >> 3,
375 				      GPIO_CMDSRC_COLDFIRE);
376 
377 	/* Restart the coprocessor */
378 	copro_ops->release_access(copro_data);
379 }
380 
381 static int aspeed_gpio_get(struct gpio_chip *gc, unsigned int offset)
382 {
383 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
384 	const struct aspeed_gpio_bank *bank = to_bank(offset);
385 
386 	return !!(ioread32(bank_reg(gpio, bank, reg_val)) & GPIO_BIT(offset));
387 }
388 
389 static void __aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
390 			      int val)
391 {
392 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
393 	const struct aspeed_gpio_bank *bank = to_bank(offset);
394 	void __iomem *addr;
395 	u32 reg;
396 
397 	addr = bank_reg(gpio, bank, reg_val);
398 	reg = gpio->dcache[GPIO_BANK(offset)];
399 
400 	if (val)
401 		reg |= GPIO_BIT(offset);
402 	else
403 		reg &= ~GPIO_BIT(offset);
404 	gpio->dcache[GPIO_BANK(offset)] = reg;
405 
406 	iowrite32(reg, addr);
407 }
408 
409 static void aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
410 			    int val)
411 {
412 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
413 	unsigned long flags;
414 	bool copro;
415 
416 	spin_lock_irqsave(&gpio->lock, flags);
417 	copro = aspeed_gpio_copro_request(gpio, offset);
418 
419 	__aspeed_gpio_set(gc, offset, val);
420 
421 	if (copro)
422 		aspeed_gpio_copro_release(gpio, offset);
423 	spin_unlock_irqrestore(&gpio->lock, flags);
424 }
425 
426 static int aspeed_gpio_dir_in(struct gpio_chip *gc, unsigned int offset)
427 {
428 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
429 	const struct aspeed_gpio_bank *bank = to_bank(offset);
430 	void __iomem *addr = bank_reg(gpio, bank, reg_dir);
431 	unsigned long flags;
432 	bool copro;
433 	u32 reg;
434 
435 	if (!have_input(gpio, offset))
436 		return -ENOTSUPP;
437 
438 	spin_lock_irqsave(&gpio->lock, flags);
439 
440 	reg = ioread32(addr);
441 	reg &= ~GPIO_BIT(offset);
442 
443 	copro = aspeed_gpio_copro_request(gpio, offset);
444 	iowrite32(reg, addr);
445 	if (copro)
446 		aspeed_gpio_copro_release(gpio, offset);
447 
448 	spin_unlock_irqrestore(&gpio->lock, flags);
449 
450 	return 0;
451 }
452 
453 static int aspeed_gpio_dir_out(struct gpio_chip *gc,
454 			       unsigned int offset, int val)
455 {
456 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
457 	const struct aspeed_gpio_bank *bank = to_bank(offset);
458 	void __iomem *addr = bank_reg(gpio, bank, reg_dir);
459 	unsigned long flags;
460 	bool copro;
461 	u32 reg;
462 
463 	if (!have_output(gpio, offset))
464 		return -ENOTSUPP;
465 
466 	spin_lock_irqsave(&gpio->lock, flags);
467 
468 	reg = ioread32(addr);
469 	reg |= GPIO_BIT(offset);
470 
471 	copro = aspeed_gpio_copro_request(gpio, offset);
472 	__aspeed_gpio_set(gc, offset, val);
473 	iowrite32(reg, addr);
474 
475 	if (copro)
476 		aspeed_gpio_copro_release(gpio, offset);
477 	spin_unlock_irqrestore(&gpio->lock, flags);
478 
479 	return 0;
480 }
481 
482 static int aspeed_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
483 {
484 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
485 	const struct aspeed_gpio_bank *bank = to_bank(offset);
486 	unsigned long flags;
487 	u32 val;
488 
489 	if (!have_input(gpio, offset))
490 		return GPIO_LINE_DIRECTION_OUT;
491 
492 	if (!have_output(gpio, offset))
493 		return GPIO_LINE_DIRECTION_IN;
494 
495 	spin_lock_irqsave(&gpio->lock, flags);
496 
497 	val = ioread32(bank_reg(gpio, bank, reg_dir)) & GPIO_BIT(offset);
498 
499 	spin_unlock_irqrestore(&gpio->lock, flags);
500 
501 	return val ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
502 }
503 
504 static inline int irqd_to_aspeed_gpio_data(struct irq_data *d,
505 					   struct aspeed_gpio **gpio,
506 					   const struct aspeed_gpio_bank **bank,
507 					   u32 *bit, int *offset)
508 {
509 	struct aspeed_gpio *internal;
510 
511 	*offset = irqd_to_hwirq(d);
512 
513 	internal = irq_data_get_irq_chip_data(d);
514 
515 	/* This might be a bit of a questionable place to check */
516 	if (!have_irq(internal, *offset))
517 		return -ENOTSUPP;
518 
519 	*gpio = internal;
520 	*bank = to_bank(*offset);
521 	*bit = GPIO_BIT(*offset);
522 
523 	return 0;
524 }
525 
526 static void aspeed_gpio_irq_ack(struct irq_data *d)
527 {
528 	const struct aspeed_gpio_bank *bank;
529 	struct aspeed_gpio *gpio;
530 	unsigned long flags;
531 	void __iomem *status_addr;
532 	int rc, offset;
533 	bool copro;
534 	u32 bit;
535 
536 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit, &offset);
537 	if (rc)
538 		return;
539 
540 	status_addr = bank_reg(gpio, bank, reg_irq_status);
541 
542 	spin_lock_irqsave(&gpio->lock, flags);
543 	copro = aspeed_gpio_copro_request(gpio, offset);
544 
545 	iowrite32(bit, status_addr);
546 
547 	if (copro)
548 		aspeed_gpio_copro_release(gpio, offset);
549 	spin_unlock_irqrestore(&gpio->lock, flags);
550 }
551 
552 static void aspeed_gpio_irq_set_mask(struct irq_data *d, bool set)
553 {
554 	const struct aspeed_gpio_bank *bank;
555 	struct aspeed_gpio *gpio;
556 	unsigned long flags;
557 	u32 reg, bit;
558 	void __iomem *addr;
559 	int rc, offset;
560 	bool copro;
561 
562 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit, &offset);
563 	if (rc)
564 		return;
565 
566 	addr = bank_reg(gpio, bank, reg_irq_enable);
567 
568 	spin_lock_irqsave(&gpio->lock, flags);
569 	copro = aspeed_gpio_copro_request(gpio, offset);
570 
571 	reg = ioread32(addr);
572 	if (set)
573 		reg |= bit;
574 	else
575 		reg &= ~bit;
576 	iowrite32(reg, addr);
577 
578 	if (copro)
579 		aspeed_gpio_copro_release(gpio, offset);
580 	spin_unlock_irqrestore(&gpio->lock, flags);
581 }
582 
583 static void aspeed_gpio_irq_mask(struct irq_data *d)
584 {
585 	aspeed_gpio_irq_set_mask(d, false);
586 }
587 
588 static void aspeed_gpio_irq_unmask(struct irq_data *d)
589 {
590 	aspeed_gpio_irq_set_mask(d, true);
591 }
592 
593 static int aspeed_gpio_set_type(struct irq_data *d, unsigned int type)
594 {
595 	u32 type0 = 0;
596 	u32 type1 = 0;
597 	u32 type2 = 0;
598 	u32 bit, reg;
599 	const struct aspeed_gpio_bank *bank;
600 	irq_flow_handler_t handler;
601 	struct aspeed_gpio *gpio;
602 	unsigned long flags;
603 	void __iomem *addr;
604 	int rc, offset;
605 	bool copro;
606 
607 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit, &offset);
608 	if (rc)
609 		return -EINVAL;
610 
611 	switch (type & IRQ_TYPE_SENSE_MASK) {
612 	case IRQ_TYPE_EDGE_BOTH:
613 		type2 |= bit;
614 		fallthrough;
615 	case IRQ_TYPE_EDGE_RISING:
616 		type0 |= bit;
617 		fallthrough;
618 	case IRQ_TYPE_EDGE_FALLING:
619 		handler = handle_edge_irq;
620 		break;
621 	case IRQ_TYPE_LEVEL_HIGH:
622 		type0 |= bit;
623 		fallthrough;
624 	case IRQ_TYPE_LEVEL_LOW:
625 		type1 |= bit;
626 		handler = handle_level_irq;
627 		break;
628 	default:
629 		return -EINVAL;
630 	}
631 
632 	spin_lock_irqsave(&gpio->lock, flags);
633 	copro = aspeed_gpio_copro_request(gpio, offset);
634 
635 	addr = bank_reg(gpio, bank, reg_irq_type0);
636 	reg = ioread32(addr);
637 	reg = (reg & ~bit) | type0;
638 	iowrite32(reg, addr);
639 
640 	addr = bank_reg(gpio, bank, reg_irq_type1);
641 	reg = ioread32(addr);
642 	reg = (reg & ~bit) | type1;
643 	iowrite32(reg, addr);
644 
645 	addr = bank_reg(gpio, bank, reg_irq_type2);
646 	reg = ioread32(addr);
647 	reg = (reg & ~bit) | type2;
648 	iowrite32(reg, addr);
649 
650 	if (copro)
651 		aspeed_gpio_copro_release(gpio, offset);
652 	spin_unlock_irqrestore(&gpio->lock, flags);
653 
654 	irq_set_handler_locked(d, handler);
655 
656 	return 0;
657 }
658 
659 static void aspeed_gpio_irq_handler(struct irq_desc *desc)
660 {
661 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
662 	struct irq_chip *ic = irq_desc_get_chip(desc);
663 	struct aspeed_gpio *data = gpiochip_get_data(gc);
664 	unsigned int i, p, banks;
665 	unsigned long reg;
666 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
667 
668 	chained_irq_enter(ic, desc);
669 
670 	banks = DIV_ROUND_UP(gpio->chip.ngpio, 32);
671 	for (i = 0; i < banks; i++) {
672 		const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i];
673 
674 		reg = ioread32(bank_reg(data, bank, reg_irq_status));
675 
676 		for_each_set_bit(p, &reg, 32)
677 			generic_handle_domain_irq(gc->irq.domain, i * 32 + p);
678 	}
679 
680 	chained_irq_exit(ic, desc);
681 }
682 
683 static void aspeed_init_irq_valid_mask(struct gpio_chip *gc,
684 				       unsigned long *valid_mask,
685 				       unsigned int ngpios)
686 {
687 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
688 	const struct aspeed_bank_props *props = gpio->config->props;
689 
690 	while (!is_bank_props_sentinel(props)) {
691 		unsigned int offset;
692 		const unsigned long int input = props->input;
693 
694 		/* Pretty crummy approach, but similar to GPIO core */
695 		for_each_clear_bit(offset, &input, 32) {
696 			unsigned int i = props->bank * 32 + offset;
697 
698 			if (i >= gpio->chip.ngpio)
699 				break;
700 
701 			clear_bit(i, valid_mask);
702 		}
703 
704 		props++;
705 	}
706 }
707 
708 static int aspeed_gpio_reset_tolerance(struct gpio_chip *chip,
709 					unsigned int offset, bool enable)
710 {
711 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
712 	unsigned long flags;
713 	void __iomem *treg;
714 	bool copro;
715 	u32 val;
716 
717 	treg = bank_reg(gpio, to_bank(offset), reg_tolerance);
718 
719 	spin_lock_irqsave(&gpio->lock, flags);
720 	copro = aspeed_gpio_copro_request(gpio, offset);
721 
722 	val = readl(treg);
723 
724 	if (enable)
725 		val |= GPIO_BIT(offset);
726 	else
727 		val &= ~GPIO_BIT(offset);
728 
729 	writel(val, treg);
730 
731 	if (copro)
732 		aspeed_gpio_copro_release(gpio, offset);
733 	spin_unlock_irqrestore(&gpio->lock, flags);
734 
735 	return 0;
736 }
737 
738 static int aspeed_gpio_request(struct gpio_chip *chip, unsigned int offset)
739 {
740 	if (!have_gpio(gpiochip_get_data(chip), offset))
741 		return -ENODEV;
742 
743 	return pinctrl_gpio_request(chip->base + offset);
744 }
745 
746 static void aspeed_gpio_free(struct gpio_chip *chip, unsigned int offset)
747 {
748 	pinctrl_gpio_free(chip->base + offset);
749 }
750 
751 static int usecs_to_cycles(struct aspeed_gpio *gpio, unsigned long usecs,
752 		u32 *cycles)
753 {
754 	u64 rate;
755 	u64 n;
756 	u32 r;
757 
758 	rate = clk_get_rate(gpio->clk);
759 	if (!rate)
760 		return -ENOTSUPP;
761 
762 	n = rate * usecs;
763 	r = do_div(n, 1000000);
764 
765 	if (n >= U32_MAX)
766 		return -ERANGE;
767 
768 	/* At least as long as the requested time */
769 	*cycles = n + (!!r);
770 
771 	return 0;
772 }
773 
774 /* Call under gpio->lock */
775 static int register_allocated_timer(struct aspeed_gpio *gpio,
776 		unsigned int offset, unsigned int timer)
777 {
778 	if (WARN(gpio->offset_timer[offset] != 0,
779 				"Offset %d already allocated timer %d\n",
780 				offset, gpio->offset_timer[offset]))
781 		return -EINVAL;
782 
783 	if (WARN(gpio->timer_users[timer] == UINT_MAX,
784 				"Timer user count would overflow\n"))
785 		return -EPERM;
786 
787 	gpio->offset_timer[offset] = timer;
788 	gpio->timer_users[timer]++;
789 
790 	return 0;
791 }
792 
793 /* Call under gpio->lock */
794 static int unregister_allocated_timer(struct aspeed_gpio *gpio,
795 		unsigned int offset)
796 {
797 	if (WARN(gpio->offset_timer[offset] == 0,
798 				"No timer allocated to offset %d\n", offset))
799 		return -EINVAL;
800 
801 	if (WARN(gpio->timer_users[gpio->offset_timer[offset]] == 0,
802 				"No users recorded for timer %d\n",
803 				gpio->offset_timer[offset]))
804 		return -EINVAL;
805 
806 	gpio->timer_users[gpio->offset_timer[offset]]--;
807 	gpio->offset_timer[offset] = 0;
808 
809 	return 0;
810 }
811 
812 /* Call under gpio->lock */
813 static inline bool timer_allocation_registered(struct aspeed_gpio *gpio,
814 		unsigned int offset)
815 {
816 	return gpio->offset_timer[offset] > 0;
817 }
818 
819 /* Call under gpio->lock */
820 static void configure_timer(struct aspeed_gpio *gpio, unsigned int offset,
821 		unsigned int timer)
822 {
823 	const struct aspeed_gpio_bank *bank = to_bank(offset);
824 	const u32 mask = GPIO_BIT(offset);
825 	void __iomem *addr;
826 	u32 val;
827 
828 	/* Note: Debounce timer isn't under control of the command
829 	 * source registers, so no need to sync with the coprocessor
830 	 */
831 	addr = bank_reg(gpio, bank, reg_debounce_sel1);
832 	val = ioread32(addr);
833 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE1(timer, offset), addr);
834 
835 	addr = bank_reg(gpio, bank, reg_debounce_sel2);
836 	val = ioread32(addr);
837 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE2(timer, offset), addr);
838 }
839 
840 static int enable_debounce(struct gpio_chip *chip, unsigned int offset,
841 				    unsigned long usecs)
842 {
843 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
844 	u32 requested_cycles;
845 	unsigned long flags;
846 	int rc;
847 	int i;
848 
849 	if (!gpio->clk)
850 		return -EINVAL;
851 
852 	rc = usecs_to_cycles(gpio, usecs, &requested_cycles);
853 	if (rc < 0) {
854 		dev_warn(chip->parent, "Failed to convert %luus to cycles at %luHz: %d\n",
855 				usecs, clk_get_rate(gpio->clk), rc);
856 		return rc;
857 	}
858 
859 	spin_lock_irqsave(&gpio->lock, flags);
860 
861 	if (timer_allocation_registered(gpio, offset)) {
862 		rc = unregister_allocated_timer(gpio, offset);
863 		if (rc < 0)
864 			goto out;
865 	}
866 
867 	/* Try to find a timer already configured for the debounce period */
868 	for (i = 1; i < ARRAY_SIZE(debounce_timers); i++) {
869 		u32 cycles;
870 
871 		cycles = ioread32(gpio->base + debounce_timers[i]);
872 		if (requested_cycles == cycles)
873 			break;
874 	}
875 
876 	if (i == ARRAY_SIZE(debounce_timers)) {
877 		int j;
878 
879 		/*
880 		 * As there are no timers configured for the requested debounce
881 		 * period, find an unused timer instead
882 		 */
883 		for (j = 1; j < ARRAY_SIZE(gpio->timer_users); j++) {
884 			if (gpio->timer_users[j] == 0)
885 				break;
886 		}
887 
888 		if (j == ARRAY_SIZE(gpio->timer_users)) {
889 			dev_warn(chip->parent,
890 					"Debounce timers exhausted, cannot debounce for period %luus\n",
891 					usecs);
892 
893 			rc = -EPERM;
894 
895 			/*
896 			 * We already adjusted the accounting to remove @offset
897 			 * as a user of its previous timer, so also configure
898 			 * the hardware so @offset has timers disabled for
899 			 * consistency.
900 			 */
901 			configure_timer(gpio, offset, 0);
902 			goto out;
903 		}
904 
905 		i = j;
906 
907 		iowrite32(requested_cycles, gpio->base + debounce_timers[i]);
908 	}
909 
910 	if (WARN(i == 0, "Cannot register index of disabled timer\n")) {
911 		rc = -EINVAL;
912 		goto out;
913 	}
914 
915 	register_allocated_timer(gpio, offset, i);
916 	configure_timer(gpio, offset, i);
917 
918 out:
919 	spin_unlock_irqrestore(&gpio->lock, flags);
920 
921 	return rc;
922 }
923 
924 static int disable_debounce(struct gpio_chip *chip, unsigned int offset)
925 {
926 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
927 	unsigned long flags;
928 	int rc;
929 
930 	spin_lock_irqsave(&gpio->lock, flags);
931 
932 	rc = unregister_allocated_timer(gpio, offset);
933 	if (!rc)
934 		configure_timer(gpio, offset, 0);
935 
936 	spin_unlock_irqrestore(&gpio->lock, flags);
937 
938 	return rc;
939 }
940 
941 static int set_debounce(struct gpio_chip *chip, unsigned int offset,
942 				    unsigned long usecs)
943 {
944 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
945 
946 	if (!have_debounce(gpio, offset))
947 		return -ENOTSUPP;
948 
949 	if (usecs)
950 		return enable_debounce(chip, offset, usecs);
951 
952 	return disable_debounce(chip, offset);
953 }
954 
955 static int aspeed_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
956 				  unsigned long config)
957 {
958 	unsigned long param = pinconf_to_config_param(config);
959 	u32 arg = pinconf_to_config_argument(config);
960 
961 	if (param == PIN_CONFIG_INPUT_DEBOUNCE)
962 		return set_debounce(chip, offset, arg);
963 	else if (param == PIN_CONFIG_BIAS_DISABLE ||
964 			param == PIN_CONFIG_BIAS_PULL_DOWN ||
965 			param == PIN_CONFIG_DRIVE_STRENGTH)
966 		return pinctrl_gpio_set_config(offset, config);
967 	else if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN ||
968 			param == PIN_CONFIG_DRIVE_OPEN_SOURCE)
969 		/* Return -ENOTSUPP to trigger emulation, as per datasheet */
970 		return -ENOTSUPP;
971 	else if (param == PIN_CONFIG_PERSIST_STATE)
972 		return aspeed_gpio_reset_tolerance(chip, offset, arg);
973 
974 	return -ENOTSUPP;
975 }
976 
977 /**
978  * aspeed_gpio_copro_set_ops - Sets the callbacks used for handshaking with
979  *                             the coprocessor for shared GPIO banks
980  * @ops: The callbacks
981  * @data: Pointer passed back to the callbacks
982  */
983 int aspeed_gpio_copro_set_ops(const struct aspeed_gpio_copro_ops *ops, void *data)
984 {
985 	copro_data = data;
986 	copro_ops = ops;
987 
988 	return 0;
989 }
990 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_set_ops);
991 
992 /**
993  * aspeed_gpio_copro_grab_gpio - Mark a GPIO used by the coprocessor. The entire
994  *                               bank gets marked and any access from the ARM will
995  *                               result in handshaking via callbacks.
996  * @desc: The GPIO to be marked
997  * @vreg_offset: If non-NULL, returns the value register offset in the GPIO space
998  * @dreg_offset: If non-NULL, returns the data latch register offset in the GPIO space
999  * @bit: If non-NULL, returns the bit number of the GPIO in the registers
1000  */
1001 int aspeed_gpio_copro_grab_gpio(struct gpio_desc *desc,
1002 				u16 *vreg_offset, u16 *dreg_offset, u8 *bit)
1003 {
1004 	struct gpio_chip *chip = gpiod_to_chip(desc);
1005 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
1006 	int rc = 0, bindex, offset = gpio_chip_hwgpio(desc);
1007 	const struct aspeed_gpio_bank *bank = to_bank(offset);
1008 	unsigned long flags;
1009 
1010 	if (!gpio->cf_copro_bankmap)
1011 		gpio->cf_copro_bankmap = kzalloc(gpio->chip.ngpio >> 3, GFP_KERNEL);
1012 	if (!gpio->cf_copro_bankmap)
1013 		return -ENOMEM;
1014 	if (offset < 0 || offset > gpio->chip.ngpio)
1015 		return -EINVAL;
1016 	bindex = offset >> 3;
1017 
1018 	spin_lock_irqsave(&gpio->lock, flags);
1019 
1020 	/* Sanity check, this shouldn't happen */
1021 	if (gpio->cf_copro_bankmap[bindex] == 0xff) {
1022 		rc = -EIO;
1023 		goto bail;
1024 	}
1025 	gpio->cf_copro_bankmap[bindex]++;
1026 
1027 	/* Switch command source */
1028 	if (gpio->cf_copro_bankmap[bindex] == 1)
1029 		aspeed_gpio_change_cmd_source(gpio, bank, bindex,
1030 					      GPIO_CMDSRC_COLDFIRE);
1031 
1032 	if (vreg_offset)
1033 		*vreg_offset = bank->val_regs;
1034 	if (dreg_offset)
1035 		*dreg_offset = bank->rdata_reg;
1036 	if (bit)
1037 		*bit = GPIO_OFFSET(offset);
1038  bail:
1039 	spin_unlock_irqrestore(&gpio->lock, flags);
1040 	return rc;
1041 }
1042 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_grab_gpio);
1043 
1044 /**
1045  * aspeed_gpio_copro_release_gpio - Unmark a GPIO used by the coprocessor.
1046  * @desc: The GPIO to be marked
1047  */
1048 int aspeed_gpio_copro_release_gpio(struct gpio_desc *desc)
1049 {
1050 	struct gpio_chip *chip = gpiod_to_chip(desc);
1051 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
1052 	int rc = 0, bindex, offset = gpio_chip_hwgpio(desc);
1053 	const struct aspeed_gpio_bank *bank = to_bank(offset);
1054 	unsigned long flags;
1055 
1056 	if (!gpio->cf_copro_bankmap)
1057 		return -ENXIO;
1058 
1059 	if (offset < 0 || offset > gpio->chip.ngpio)
1060 		return -EINVAL;
1061 	bindex = offset >> 3;
1062 
1063 	spin_lock_irqsave(&gpio->lock, flags);
1064 
1065 	/* Sanity check, this shouldn't happen */
1066 	if (gpio->cf_copro_bankmap[bindex] == 0) {
1067 		rc = -EIO;
1068 		goto bail;
1069 	}
1070 	gpio->cf_copro_bankmap[bindex]--;
1071 
1072 	/* Switch command source */
1073 	if (gpio->cf_copro_bankmap[bindex] == 0)
1074 		aspeed_gpio_change_cmd_source(gpio, bank, bindex,
1075 					      GPIO_CMDSRC_ARM);
1076  bail:
1077 	spin_unlock_irqrestore(&gpio->lock, flags);
1078 	return rc;
1079 }
1080 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_release_gpio);
1081 
1082 /*
1083  * Any banks not specified in a struct aspeed_bank_props array are assumed to
1084  * have the properties:
1085  *
1086  *     { .input = 0xffffffff, .output = 0xffffffff }
1087  */
1088 
1089 static const struct aspeed_bank_props ast2400_bank_props[] = {
1090 	/*     input	  output   */
1091 	{ 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
1092 	{ 6, 0x0000000f, 0x0fffff0f }, /* Y/Z/AA/AB, two 4-GPIO holes */
1093 	{ },
1094 };
1095 
1096 static const struct aspeed_gpio_config ast2400_config =
1097 	/* 220 for simplicity, really 216 with two 4-GPIO holes, four at end */
1098 	{ .nr_gpios = 220, .props = ast2400_bank_props, };
1099 
1100 static const struct aspeed_bank_props ast2500_bank_props[] = {
1101 	/*     input	  output   */
1102 	{ 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
1103 	{ 6, 0x0fffffff, 0x0fffffff }, /* Y/Z/AA/AB, 4-GPIO hole */
1104 	{ 7, 0x000000ff, 0x000000ff }, /* AC */
1105 	{ },
1106 };
1107 
1108 static const struct aspeed_gpio_config ast2500_config =
1109 	/* 232 for simplicity, actual number is 228 (4-GPIO hole in GPIOAB) */
1110 	{ .nr_gpios = 232, .props = ast2500_bank_props, };
1111 
1112 static const struct aspeed_bank_props ast2600_bank_props[] = {
1113 	/*     input	  output   */
1114 	{4, 0xffffffff,  0x00ffffff}, /* Q/R/S/T */
1115 	{5, 0xffffffff,  0xffffff00}, /* U/V/W/X */
1116 	{6, 0x0000ffff,  0x0000ffff}, /* Y/Z */
1117 	{ },
1118 };
1119 
1120 static const struct aspeed_gpio_config ast2600_config =
1121 	/*
1122 	 * ast2600 has two controllers one with 208 GPIOs and one with 36 GPIOs.
1123 	 * We expect ngpio being set in the device tree and this is a fallback
1124 	 * option.
1125 	 */
1126 	{ .nr_gpios = 208, .props = ast2600_bank_props, };
1127 
1128 static const struct of_device_id aspeed_gpio_of_table[] = {
1129 	{ .compatible = "aspeed,ast2400-gpio", .data = &ast2400_config, },
1130 	{ .compatible = "aspeed,ast2500-gpio", .data = &ast2500_config, },
1131 	{ .compatible = "aspeed,ast2600-gpio", .data = &ast2600_config, },
1132 	{}
1133 };
1134 MODULE_DEVICE_TABLE(of, aspeed_gpio_of_table);
1135 
1136 static int __init aspeed_gpio_probe(struct platform_device *pdev)
1137 {
1138 	const struct of_device_id *gpio_id;
1139 	struct aspeed_gpio *gpio;
1140 	int rc, i, banks, err;
1141 	u32 ngpio;
1142 
1143 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
1144 	if (!gpio)
1145 		return -ENOMEM;
1146 
1147 	gpio->base = devm_platform_ioremap_resource(pdev, 0);
1148 	if (IS_ERR(gpio->base))
1149 		return PTR_ERR(gpio->base);
1150 
1151 	spin_lock_init(&gpio->lock);
1152 
1153 	gpio_id = of_match_node(aspeed_gpio_of_table, pdev->dev.of_node);
1154 	if (!gpio_id)
1155 		return -EINVAL;
1156 
1157 	gpio->clk = of_clk_get(pdev->dev.of_node, 0);
1158 	if (IS_ERR(gpio->clk)) {
1159 		dev_warn(&pdev->dev,
1160 				"Failed to get clock from devicetree, debouncing disabled\n");
1161 		gpio->clk = NULL;
1162 	}
1163 
1164 	gpio->config = gpio_id->data;
1165 
1166 	gpio->chip.parent = &pdev->dev;
1167 	err = of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpio);
1168 	gpio->chip.ngpio = (u16) ngpio;
1169 	if (err)
1170 		gpio->chip.ngpio = gpio->config->nr_gpios;
1171 	gpio->chip.direction_input = aspeed_gpio_dir_in;
1172 	gpio->chip.direction_output = aspeed_gpio_dir_out;
1173 	gpio->chip.get_direction = aspeed_gpio_get_direction;
1174 	gpio->chip.request = aspeed_gpio_request;
1175 	gpio->chip.free = aspeed_gpio_free;
1176 	gpio->chip.get = aspeed_gpio_get;
1177 	gpio->chip.set = aspeed_gpio_set;
1178 	gpio->chip.set_config = aspeed_gpio_set_config;
1179 	gpio->chip.label = dev_name(&pdev->dev);
1180 	gpio->chip.base = -1;
1181 
1182 	/* Allocate a cache of the output registers */
1183 	banks = DIV_ROUND_UP(gpio->chip.ngpio, 32);
1184 	gpio->dcache = devm_kcalloc(&pdev->dev,
1185 				    banks, sizeof(u32), GFP_KERNEL);
1186 	if (!gpio->dcache)
1187 		return -ENOMEM;
1188 
1189 	/*
1190 	 * Populate it with initial values read from the HW and switch
1191 	 * all command sources to the ARM by default
1192 	 */
1193 	for (i = 0; i < banks; i++) {
1194 		const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i];
1195 		void __iomem *addr = bank_reg(gpio, bank, reg_rdata);
1196 		gpio->dcache[i] = ioread32(addr);
1197 		aspeed_gpio_change_cmd_source(gpio, bank, 0, GPIO_CMDSRC_ARM);
1198 		aspeed_gpio_change_cmd_source(gpio, bank, 1, GPIO_CMDSRC_ARM);
1199 		aspeed_gpio_change_cmd_source(gpio, bank, 2, GPIO_CMDSRC_ARM);
1200 		aspeed_gpio_change_cmd_source(gpio, bank, 3, GPIO_CMDSRC_ARM);
1201 	}
1202 
1203 	/* Optionally set up an irqchip if there is an IRQ */
1204 	rc = platform_get_irq(pdev, 0);
1205 	if (rc > 0) {
1206 		struct gpio_irq_chip *girq;
1207 
1208 		gpio->irq = rc;
1209 		girq = &gpio->chip.irq;
1210 		girq->chip = &gpio->irqc;
1211 		girq->chip->name = dev_name(&pdev->dev);
1212 		girq->chip->irq_ack = aspeed_gpio_irq_ack;
1213 		girq->chip->irq_mask = aspeed_gpio_irq_mask;
1214 		girq->chip->irq_unmask = aspeed_gpio_irq_unmask;
1215 		girq->chip->irq_set_type = aspeed_gpio_set_type;
1216 		girq->parent_handler = aspeed_gpio_irq_handler;
1217 		girq->num_parents = 1;
1218 		girq->parents = devm_kcalloc(&pdev->dev, 1,
1219 					     sizeof(*girq->parents),
1220 					     GFP_KERNEL);
1221 		if (!girq->parents)
1222 			return -ENOMEM;
1223 		girq->parents[0] = gpio->irq;
1224 		girq->default_type = IRQ_TYPE_NONE;
1225 		girq->handler = handle_bad_irq;
1226 		girq->init_valid_mask = aspeed_init_irq_valid_mask;
1227 	}
1228 
1229 	gpio->offset_timer =
1230 		devm_kzalloc(&pdev->dev, gpio->chip.ngpio, GFP_KERNEL);
1231 	if (!gpio->offset_timer)
1232 		return -ENOMEM;
1233 
1234 	rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
1235 	if (rc < 0)
1236 		return rc;
1237 
1238 	return 0;
1239 }
1240 
1241 static struct platform_driver aspeed_gpio_driver = {
1242 	.driver = {
1243 		.name = KBUILD_MODNAME,
1244 		.of_match_table = aspeed_gpio_of_table,
1245 	},
1246 };
1247 
1248 module_platform_driver_probe(aspeed_gpio_driver, aspeed_gpio_probe);
1249 
1250 MODULE_DESCRIPTION("Aspeed GPIO Driver");
1251 MODULE_LICENSE("GPL");
1252