xref: /openbmc/linux/drivers/gpio/gpio-aspeed.c (revision afba8b0a)
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, girq, 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 			girq = irq_find_mapping(gc->irq.domain, i * 32 + p);
678 			generic_handle_irq(girq);
679 		}
680 
681 	}
682 
683 	chained_irq_exit(ic, desc);
684 }
685 
686 static void aspeed_init_irq_valid_mask(struct gpio_chip *gc,
687 				       unsigned long *valid_mask,
688 				       unsigned int ngpios)
689 {
690 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
691 	const struct aspeed_bank_props *props = gpio->config->props;
692 
693 	while (!is_bank_props_sentinel(props)) {
694 		unsigned int offset;
695 		const unsigned long int input = props->input;
696 
697 		/* Pretty crummy approach, but similar to GPIO core */
698 		for_each_clear_bit(offset, &input, 32) {
699 			unsigned int i = props->bank * 32 + offset;
700 
701 			if (i >= gpio->chip.ngpio)
702 				break;
703 
704 			clear_bit(i, valid_mask);
705 		}
706 
707 		props++;
708 	}
709 }
710 
711 static int aspeed_gpio_reset_tolerance(struct gpio_chip *chip,
712 					unsigned int offset, bool enable)
713 {
714 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
715 	unsigned long flags;
716 	void __iomem *treg;
717 	bool copro;
718 	u32 val;
719 
720 	treg = bank_reg(gpio, to_bank(offset), reg_tolerance);
721 
722 	spin_lock_irqsave(&gpio->lock, flags);
723 	copro = aspeed_gpio_copro_request(gpio, offset);
724 
725 	val = readl(treg);
726 
727 	if (enable)
728 		val |= GPIO_BIT(offset);
729 	else
730 		val &= ~GPIO_BIT(offset);
731 
732 	writel(val, treg);
733 
734 	if (copro)
735 		aspeed_gpio_copro_release(gpio, offset);
736 	spin_unlock_irqrestore(&gpio->lock, flags);
737 
738 	return 0;
739 }
740 
741 static int aspeed_gpio_request(struct gpio_chip *chip, unsigned int offset)
742 {
743 	if (!have_gpio(gpiochip_get_data(chip), offset))
744 		return -ENODEV;
745 
746 	return pinctrl_gpio_request(chip->base + offset);
747 }
748 
749 static void aspeed_gpio_free(struct gpio_chip *chip, unsigned int offset)
750 {
751 	pinctrl_gpio_free(chip->base + offset);
752 }
753 
754 static int usecs_to_cycles(struct aspeed_gpio *gpio, unsigned long usecs,
755 		u32 *cycles)
756 {
757 	u64 rate;
758 	u64 n;
759 	u32 r;
760 
761 	rate = clk_get_rate(gpio->clk);
762 	if (!rate)
763 		return -ENOTSUPP;
764 
765 	n = rate * usecs;
766 	r = do_div(n, 1000000);
767 
768 	if (n >= U32_MAX)
769 		return -ERANGE;
770 
771 	/* At least as long as the requested time */
772 	*cycles = n + (!!r);
773 
774 	return 0;
775 }
776 
777 /* Call under gpio->lock */
778 static int register_allocated_timer(struct aspeed_gpio *gpio,
779 		unsigned int offset, unsigned int timer)
780 {
781 	if (WARN(gpio->offset_timer[offset] != 0,
782 				"Offset %d already allocated timer %d\n",
783 				offset, gpio->offset_timer[offset]))
784 		return -EINVAL;
785 
786 	if (WARN(gpio->timer_users[timer] == UINT_MAX,
787 				"Timer user count would overflow\n"))
788 		return -EPERM;
789 
790 	gpio->offset_timer[offset] = timer;
791 	gpio->timer_users[timer]++;
792 
793 	return 0;
794 }
795 
796 /* Call under gpio->lock */
797 static int unregister_allocated_timer(struct aspeed_gpio *gpio,
798 		unsigned int offset)
799 {
800 	if (WARN(gpio->offset_timer[offset] == 0,
801 				"No timer allocated to offset %d\n", offset))
802 		return -EINVAL;
803 
804 	if (WARN(gpio->timer_users[gpio->offset_timer[offset]] == 0,
805 				"No users recorded for timer %d\n",
806 				gpio->offset_timer[offset]))
807 		return -EINVAL;
808 
809 	gpio->timer_users[gpio->offset_timer[offset]]--;
810 	gpio->offset_timer[offset] = 0;
811 
812 	return 0;
813 }
814 
815 /* Call under gpio->lock */
816 static inline bool timer_allocation_registered(struct aspeed_gpio *gpio,
817 		unsigned int offset)
818 {
819 	return gpio->offset_timer[offset] > 0;
820 }
821 
822 /* Call under gpio->lock */
823 static void configure_timer(struct aspeed_gpio *gpio, unsigned int offset,
824 		unsigned int timer)
825 {
826 	const struct aspeed_gpio_bank *bank = to_bank(offset);
827 	const u32 mask = GPIO_BIT(offset);
828 	void __iomem *addr;
829 	u32 val;
830 
831 	/* Note: Debounce timer isn't under control of the command
832 	 * source registers, so no need to sync with the coprocessor
833 	 */
834 	addr = bank_reg(gpio, bank, reg_debounce_sel1);
835 	val = ioread32(addr);
836 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE1(timer, offset), addr);
837 
838 	addr = bank_reg(gpio, bank, reg_debounce_sel2);
839 	val = ioread32(addr);
840 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE2(timer, offset), addr);
841 }
842 
843 static int enable_debounce(struct gpio_chip *chip, unsigned int offset,
844 				    unsigned long usecs)
845 {
846 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
847 	u32 requested_cycles;
848 	unsigned long flags;
849 	int rc;
850 	int i;
851 
852 	if (!gpio->clk)
853 		return -EINVAL;
854 
855 	rc = usecs_to_cycles(gpio, usecs, &requested_cycles);
856 	if (rc < 0) {
857 		dev_warn(chip->parent, "Failed to convert %luus to cycles at %luHz: %d\n",
858 				usecs, clk_get_rate(gpio->clk), rc);
859 		return rc;
860 	}
861 
862 	spin_lock_irqsave(&gpio->lock, flags);
863 
864 	if (timer_allocation_registered(gpio, offset)) {
865 		rc = unregister_allocated_timer(gpio, offset);
866 		if (rc < 0)
867 			goto out;
868 	}
869 
870 	/* Try to find a timer already configured for the debounce period */
871 	for (i = 1; i < ARRAY_SIZE(debounce_timers); i++) {
872 		u32 cycles;
873 
874 		cycles = ioread32(gpio->base + debounce_timers[i]);
875 		if (requested_cycles == cycles)
876 			break;
877 	}
878 
879 	if (i == ARRAY_SIZE(debounce_timers)) {
880 		int j;
881 
882 		/*
883 		 * As there are no timers configured for the requested debounce
884 		 * period, find an unused timer instead
885 		 */
886 		for (j = 1; j < ARRAY_SIZE(gpio->timer_users); j++) {
887 			if (gpio->timer_users[j] == 0)
888 				break;
889 		}
890 
891 		if (j == ARRAY_SIZE(gpio->timer_users)) {
892 			dev_warn(chip->parent,
893 					"Debounce timers exhausted, cannot debounce for period %luus\n",
894 					usecs);
895 
896 			rc = -EPERM;
897 
898 			/*
899 			 * We already adjusted the accounting to remove @offset
900 			 * as a user of its previous timer, so also configure
901 			 * the hardware so @offset has timers disabled for
902 			 * consistency.
903 			 */
904 			configure_timer(gpio, offset, 0);
905 			goto out;
906 		}
907 
908 		i = j;
909 
910 		iowrite32(requested_cycles, gpio->base + debounce_timers[i]);
911 	}
912 
913 	if (WARN(i == 0, "Cannot register index of disabled timer\n")) {
914 		rc = -EINVAL;
915 		goto out;
916 	}
917 
918 	register_allocated_timer(gpio, offset, i);
919 	configure_timer(gpio, offset, i);
920 
921 out:
922 	spin_unlock_irqrestore(&gpio->lock, flags);
923 
924 	return rc;
925 }
926 
927 static int disable_debounce(struct gpio_chip *chip, unsigned int offset)
928 {
929 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
930 	unsigned long flags;
931 	int rc;
932 
933 	spin_lock_irqsave(&gpio->lock, flags);
934 
935 	rc = unregister_allocated_timer(gpio, offset);
936 	if (!rc)
937 		configure_timer(gpio, offset, 0);
938 
939 	spin_unlock_irqrestore(&gpio->lock, flags);
940 
941 	return rc;
942 }
943 
944 static int set_debounce(struct gpio_chip *chip, unsigned int offset,
945 				    unsigned long usecs)
946 {
947 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
948 
949 	if (!have_debounce(gpio, offset))
950 		return -ENOTSUPP;
951 
952 	if (usecs)
953 		return enable_debounce(chip, offset, usecs);
954 
955 	return disable_debounce(chip, offset);
956 }
957 
958 static int aspeed_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
959 				  unsigned long config)
960 {
961 	unsigned long param = pinconf_to_config_param(config);
962 	u32 arg = pinconf_to_config_argument(config);
963 
964 	if (param == PIN_CONFIG_INPUT_DEBOUNCE)
965 		return set_debounce(chip, offset, arg);
966 	else if (param == PIN_CONFIG_BIAS_DISABLE ||
967 			param == PIN_CONFIG_BIAS_PULL_DOWN ||
968 			param == PIN_CONFIG_DRIVE_STRENGTH)
969 		return pinctrl_gpio_set_config(offset, config);
970 	else if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN ||
971 			param == PIN_CONFIG_DRIVE_OPEN_SOURCE)
972 		/* Return -ENOTSUPP to trigger emulation, as per datasheet */
973 		return -ENOTSUPP;
974 	else if (param == PIN_CONFIG_PERSIST_STATE)
975 		return aspeed_gpio_reset_tolerance(chip, offset, arg);
976 
977 	return -ENOTSUPP;
978 }
979 
980 /**
981  * aspeed_gpio_copro_set_ops - Sets the callbacks used for handshaking with
982  *                             the coprocessor for shared GPIO banks
983  * @ops: The callbacks
984  * @data: Pointer passed back to the callbacks
985  */
986 int aspeed_gpio_copro_set_ops(const struct aspeed_gpio_copro_ops *ops, void *data)
987 {
988 	copro_data = data;
989 	copro_ops = ops;
990 
991 	return 0;
992 }
993 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_set_ops);
994 
995 /**
996  * aspeed_gpio_copro_grab_gpio - Mark a GPIO used by the coprocessor. The entire
997  *                               bank gets marked and any access from the ARM will
998  *                               result in handshaking via callbacks.
999  * @desc: The GPIO to be marked
1000  * @vreg_offset: If non-NULL, returns the value register offset in the GPIO space
1001  * @dreg_offset: If non-NULL, returns the data latch register offset in the GPIO space
1002  * @bit: If non-NULL, returns the bit number of the GPIO in the registers
1003  */
1004 int aspeed_gpio_copro_grab_gpio(struct gpio_desc *desc,
1005 				u16 *vreg_offset, u16 *dreg_offset, u8 *bit)
1006 {
1007 	struct gpio_chip *chip = gpiod_to_chip(desc);
1008 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
1009 	int rc = 0, bindex, offset = gpio_chip_hwgpio(desc);
1010 	const struct aspeed_gpio_bank *bank = to_bank(offset);
1011 	unsigned long flags;
1012 
1013 	if (!gpio->cf_copro_bankmap)
1014 		gpio->cf_copro_bankmap = kzalloc(gpio->chip.ngpio >> 3, GFP_KERNEL);
1015 	if (!gpio->cf_copro_bankmap)
1016 		return -ENOMEM;
1017 	if (offset < 0 || offset > gpio->chip.ngpio)
1018 		return -EINVAL;
1019 	bindex = offset >> 3;
1020 
1021 	spin_lock_irqsave(&gpio->lock, flags);
1022 
1023 	/* Sanity check, this shouldn't happen */
1024 	if (gpio->cf_copro_bankmap[bindex] == 0xff) {
1025 		rc = -EIO;
1026 		goto bail;
1027 	}
1028 	gpio->cf_copro_bankmap[bindex]++;
1029 
1030 	/* Switch command source */
1031 	if (gpio->cf_copro_bankmap[bindex] == 1)
1032 		aspeed_gpio_change_cmd_source(gpio, bank, bindex,
1033 					      GPIO_CMDSRC_COLDFIRE);
1034 
1035 	if (vreg_offset)
1036 		*vreg_offset = bank->val_regs;
1037 	if (dreg_offset)
1038 		*dreg_offset = bank->rdata_reg;
1039 	if (bit)
1040 		*bit = GPIO_OFFSET(offset);
1041  bail:
1042 	spin_unlock_irqrestore(&gpio->lock, flags);
1043 	return rc;
1044 }
1045 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_grab_gpio);
1046 
1047 /**
1048  * aspeed_gpio_copro_release_gpio - Unmark a GPIO used by the coprocessor.
1049  * @desc: The GPIO to be marked
1050  */
1051 int aspeed_gpio_copro_release_gpio(struct gpio_desc *desc)
1052 {
1053 	struct gpio_chip *chip = gpiod_to_chip(desc);
1054 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
1055 	int rc = 0, bindex, offset = gpio_chip_hwgpio(desc);
1056 	const struct aspeed_gpio_bank *bank = to_bank(offset);
1057 	unsigned long flags;
1058 
1059 	if (!gpio->cf_copro_bankmap)
1060 		return -ENXIO;
1061 
1062 	if (offset < 0 || offset > gpio->chip.ngpio)
1063 		return -EINVAL;
1064 	bindex = offset >> 3;
1065 
1066 	spin_lock_irqsave(&gpio->lock, flags);
1067 
1068 	/* Sanity check, this shouldn't happen */
1069 	if (gpio->cf_copro_bankmap[bindex] == 0) {
1070 		rc = -EIO;
1071 		goto bail;
1072 	}
1073 	gpio->cf_copro_bankmap[bindex]--;
1074 
1075 	/* Switch command source */
1076 	if (gpio->cf_copro_bankmap[bindex] == 0)
1077 		aspeed_gpio_change_cmd_source(gpio, bank, bindex,
1078 					      GPIO_CMDSRC_ARM);
1079  bail:
1080 	spin_unlock_irqrestore(&gpio->lock, flags);
1081 	return rc;
1082 }
1083 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_release_gpio);
1084 
1085 /*
1086  * Any banks not specified in a struct aspeed_bank_props array are assumed to
1087  * have the properties:
1088  *
1089  *     { .input = 0xffffffff, .output = 0xffffffff }
1090  */
1091 
1092 static const struct aspeed_bank_props ast2400_bank_props[] = {
1093 	/*     input	  output   */
1094 	{ 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
1095 	{ 6, 0x0000000f, 0x0fffff0f }, /* Y/Z/AA/AB, two 4-GPIO holes */
1096 	{ },
1097 };
1098 
1099 static const struct aspeed_gpio_config ast2400_config =
1100 	/* 220 for simplicity, really 216 with two 4-GPIO holes, four at end */
1101 	{ .nr_gpios = 220, .props = ast2400_bank_props, };
1102 
1103 static const struct aspeed_bank_props ast2500_bank_props[] = {
1104 	/*     input	  output   */
1105 	{ 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
1106 	{ 6, 0x0fffffff, 0x0fffffff }, /* Y/Z/AA/AB, 4-GPIO hole */
1107 	{ 7, 0x000000ff, 0x000000ff }, /* AC */
1108 	{ },
1109 };
1110 
1111 static const struct aspeed_gpio_config ast2500_config =
1112 	/* 232 for simplicity, actual number is 228 (4-GPIO hole in GPIOAB) */
1113 	{ .nr_gpios = 232, .props = ast2500_bank_props, };
1114 
1115 static const struct aspeed_bank_props ast2600_bank_props[] = {
1116 	/*     input	  output   */
1117 	{5, 0xffffffff,  0xffffff00}, /* U/V/W/X */
1118 	{6, 0x0000ffff,  0x0000ffff}, /* Y/Z */
1119 	{ },
1120 };
1121 
1122 static const struct aspeed_gpio_config ast2600_config =
1123 	/*
1124 	 * ast2600 has two controllers one with 208 GPIOs and one with 36 GPIOs.
1125 	 * We expect ngpio being set in the device tree and this is a fallback
1126 	 * option.
1127 	 */
1128 	{ .nr_gpios = 208, .props = ast2600_bank_props, };
1129 
1130 static const struct of_device_id aspeed_gpio_of_table[] = {
1131 	{ .compatible = "aspeed,ast2400-gpio", .data = &ast2400_config, },
1132 	{ .compatible = "aspeed,ast2500-gpio", .data = &ast2500_config, },
1133 	{ .compatible = "aspeed,ast2600-gpio", .data = &ast2600_config, },
1134 	{}
1135 };
1136 MODULE_DEVICE_TABLE(of, aspeed_gpio_of_table);
1137 
1138 static int __init aspeed_gpio_probe(struct platform_device *pdev)
1139 {
1140 	const struct of_device_id *gpio_id;
1141 	struct aspeed_gpio *gpio;
1142 	int rc, i, banks, err;
1143 	u32 ngpio;
1144 
1145 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
1146 	if (!gpio)
1147 		return -ENOMEM;
1148 
1149 	gpio->base = devm_platform_ioremap_resource(pdev, 0);
1150 	if (IS_ERR(gpio->base))
1151 		return PTR_ERR(gpio->base);
1152 
1153 	spin_lock_init(&gpio->lock);
1154 
1155 	gpio_id = of_match_node(aspeed_gpio_of_table, pdev->dev.of_node);
1156 	if (!gpio_id)
1157 		return -EINVAL;
1158 
1159 	gpio->clk = of_clk_get(pdev->dev.of_node, 0);
1160 	if (IS_ERR(gpio->clk)) {
1161 		dev_warn(&pdev->dev,
1162 				"Failed to get clock from devicetree, debouncing disabled\n");
1163 		gpio->clk = NULL;
1164 	}
1165 
1166 	gpio->config = gpio_id->data;
1167 
1168 	gpio->chip.parent = &pdev->dev;
1169 	err = of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpio);
1170 	gpio->chip.ngpio = (u16) ngpio;
1171 	if (err)
1172 		gpio->chip.ngpio = gpio->config->nr_gpios;
1173 	gpio->chip.direction_input = aspeed_gpio_dir_in;
1174 	gpio->chip.direction_output = aspeed_gpio_dir_out;
1175 	gpio->chip.get_direction = aspeed_gpio_get_direction;
1176 	gpio->chip.request = aspeed_gpio_request;
1177 	gpio->chip.free = aspeed_gpio_free;
1178 	gpio->chip.get = aspeed_gpio_get;
1179 	gpio->chip.set = aspeed_gpio_set;
1180 	gpio->chip.set_config = aspeed_gpio_set_config;
1181 	gpio->chip.label = dev_name(&pdev->dev);
1182 	gpio->chip.base = -1;
1183 
1184 	/* Allocate a cache of the output registers */
1185 	banks = DIV_ROUND_UP(gpio->chip.ngpio, 32);
1186 	gpio->dcache = devm_kcalloc(&pdev->dev,
1187 				    banks, sizeof(u32), GFP_KERNEL);
1188 	if (!gpio->dcache)
1189 		return -ENOMEM;
1190 
1191 	/*
1192 	 * Populate it with initial values read from the HW and switch
1193 	 * all command sources to the ARM by default
1194 	 */
1195 	for (i = 0; i < banks; i++) {
1196 		const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i];
1197 		void __iomem *addr = bank_reg(gpio, bank, reg_rdata);
1198 		gpio->dcache[i] = ioread32(addr);
1199 		aspeed_gpio_change_cmd_source(gpio, bank, 0, GPIO_CMDSRC_ARM);
1200 		aspeed_gpio_change_cmd_source(gpio, bank, 1, GPIO_CMDSRC_ARM);
1201 		aspeed_gpio_change_cmd_source(gpio, bank, 2, GPIO_CMDSRC_ARM);
1202 		aspeed_gpio_change_cmd_source(gpio, bank, 3, GPIO_CMDSRC_ARM);
1203 	}
1204 
1205 	/* Optionally set up an irqchip if there is an IRQ */
1206 	rc = platform_get_irq(pdev, 0);
1207 	if (rc > 0) {
1208 		struct gpio_irq_chip *girq;
1209 
1210 		gpio->irq = rc;
1211 		girq = &gpio->chip.irq;
1212 		girq->chip = &gpio->irqc;
1213 		girq->chip->name = dev_name(&pdev->dev);
1214 		girq->chip->irq_ack = aspeed_gpio_irq_ack;
1215 		girq->chip->irq_mask = aspeed_gpio_irq_mask;
1216 		girq->chip->irq_unmask = aspeed_gpio_irq_unmask;
1217 		girq->chip->irq_set_type = aspeed_gpio_set_type;
1218 		girq->parent_handler = aspeed_gpio_irq_handler;
1219 		girq->num_parents = 1;
1220 		girq->parents = devm_kcalloc(&pdev->dev, 1,
1221 					     sizeof(*girq->parents),
1222 					     GFP_KERNEL);
1223 		if (!girq->parents)
1224 			return -ENOMEM;
1225 		girq->parents[0] = gpio->irq;
1226 		girq->default_type = IRQ_TYPE_NONE;
1227 		girq->handler = handle_bad_irq;
1228 		girq->init_valid_mask = aspeed_init_irq_valid_mask;
1229 	}
1230 
1231 	gpio->offset_timer =
1232 		devm_kzalloc(&pdev->dev, gpio->chip.ngpio, GFP_KERNEL);
1233 	if (!gpio->offset_timer)
1234 		return -ENOMEM;
1235 
1236 	rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
1237 	if (rc < 0)
1238 		return rc;
1239 
1240 	return 0;
1241 }
1242 
1243 static struct platform_driver aspeed_gpio_driver = {
1244 	.driver = {
1245 		.name = KBUILD_MODNAME,
1246 		.of_match_table = aspeed_gpio_of_table,
1247 	},
1248 };
1249 
1250 module_platform_driver_probe(aspeed_gpio_driver, aspeed_gpio_probe);
1251 
1252 MODULE_DESCRIPTION("Aspeed GPIO Driver");
1253 MODULE_LICENSE("GPL");
1254