xref: /linux/drivers/gpio/gpio-aspeed.c (revision 17cfcb68af3bc7d5e8ae08779b1853310a2949f3)
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 0;
491 
492 	if (!have_output(gpio, offset))
493 		return 1;
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;
502 
503 }
504 
505 static inline int irqd_to_aspeed_gpio_data(struct irq_data *d,
506 					   struct aspeed_gpio **gpio,
507 					   const struct aspeed_gpio_bank **bank,
508 					   u32 *bit, int *offset)
509 {
510 	struct aspeed_gpio *internal;
511 
512 	*offset = irqd_to_hwirq(d);
513 
514 	internal = irq_data_get_irq_chip_data(d);
515 
516 	/* This might be a bit of a questionable place to check */
517 	if (!have_irq(internal, *offset))
518 		return -ENOTSUPP;
519 
520 	*gpio = internal;
521 	*bank = to_bank(*offset);
522 	*bit = GPIO_BIT(*offset);
523 
524 	return 0;
525 }
526 
527 static void aspeed_gpio_irq_ack(struct irq_data *d)
528 {
529 	const struct aspeed_gpio_bank *bank;
530 	struct aspeed_gpio *gpio;
531 	unsigned long flags;
532 	void __iomem *status_addr;
533 	int rc, offset;
534 	bool copro;
535 	u32 bit;
536 
537 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit, &offset);
538 	if (rc)
539 		return;
540 
541 	status_addr = bank_reg(gpio, bank, reg_irq_status);
542 
543 	spin_lock_irqsave(&gpio->lock, flags);
544 	copro = aspeed_gpio_copro_request(gpio, offset);
545 
546 	iowrite32(bit, status_addr);
547 
548 	if (copro)
549 		aspeed_gpio_copro_release(gpio, offset);
550 	spin_unlock_irqrestore(&gpio->lock, flags);
551 }
552 
553 static void aspeed_gpio_irq_set_mask(struct irq_data *d, bool set)
554 {
555 	const struct aspeed_gpio_bank *bank;
556 	struct aspeed_gpio *gpio;
557 	unsigned long flags;
558 	u32 reg, bit;
559 	void __iomem *addr;
560 	int rc, offset;
561 	bool copro;
562 
563 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit, &offset);
564 	if (rc)
565 		return;
566 
567 	addr = bank_reg(gpio, bank, reg_irq_enable);
568 
569 	spin_lock_irqsave(&gpio->lock, flags);
570 	copro = aspeed_gpio_copro_request(gpio, offset);
571 
572 	reg = ioread32(addr);
573 	if (set)
574 		reg |= bit;
575 	else
576 		reg &= ~bit;
577 	iowrite32(reg, addr);
578 
579 	if (copro)
580 		aspeed_gpio_copro_release(gpio, offset);
581 	spin_unlock_irqrestore(&gpio->lock, flags);
582 }
583 
584 static void aspeed_gpio_irq_mask(struct irq_data *d)
585 {
586 	aspeed_gpio_irq_set_mask(d, false);
587 }
588 
589 static void aspeed_gpio_irq_unmask(struct irq_data *d)
590 {
591 	aspeed_gpio_irq_set_mask(d, true);
592 }
593 
594 static int aspeed_gpio_set_type(struct irq_data *d, unsigned int type)
595 {
596 	u32 type0 = 0;
597 	u32 type1 = 0;
598 	u32 type2 = 0;
599 	u32 bit, reg;
600 	const struct aspeed_gpio_bank *bank;
601 	irq_flow_handler_t handler;
602 	struct aspeed_gpio *gpio;
603 	unsigned long flags;
604 	void __iomem *addr;
605 	int rc, offset;
606 	bool copro;
607 
608 	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit, &offset);
609 	if (rc)
610 		return -EINVAL;
611 
612 	switch (type & IRQ_TYPE_SENSE_MASK) {
613 	case IRQ_TYPE_EDGE_BOTH:
614 		type2 |= bit;
615 		/* fall through */
616 	case IRQ_TYPE_EDGE_RISING:
617 		type0 |= bit;
618 		/* fall through */
619 	case IRQ_TYPE_EDGE_FALLING:
620 		handler = handle_edge_irq;
621 		break;
622 	case IRQ_TYPE_LEVEL_HIGH:
623 		type0 |= bit;
624 		/* fall through */
625 	case IRQ_TYPE_LEVEL_LOW:
626 		type1 |= bit;
627 		handler = handle_level_irq;
628 		break;
629 	default:
630 		return -EINVAL;
631 	}
632 
633 	spin_lock_irqsave(&gpio->lock, flags);
634 	copro = aspeed_gpio_copro_request(gpio, offset);
635 
636 	addr = bank_reg(gpio, bank, reg_irq_type0);
637 	reg = ioread32(addr);
638 	reg = (reg & ~bit) | type0;
639 	iowrite32(reg, addr);
640 
641 	addr = bank_reg(gpio, bank, reg_irq_type1);
642 	reg = ioread32(addr);
643 	reg = (reg & ~bit) | type1;
644 	iowrite32(reg, addr);
645 
646 	addr = bank_reg(gpio, bank, reg_irq_type2);
647 	reg = ioread32(addr);
648 	reg = (reg & ~bit) | type2;
649 	iowrite32(reg, addr);
650 
651 	if (copro)
652 		aspeed_gpio_copro_release(gpio, offset);
653 	spin_unlock_irqrestore(&gpio->lock, flags);
654 
655 	irq_set_handler_locked(d, handler);
656 
657 	return 0;
658 }
659 
660 static void aspeed_gpio_irq_handler(struct irq_desc *desc)
661 {
662 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
663 	struct irq_chip *ic = irq_desc_get_chip(desc);
664 	struct aspeed_gpio *data = gpiochip_get_data(gc);
665 	unsigned int i, p, girq, banks;
666 	unsigned long reg;
667 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
668 
669 	chained_irq_enter(ic, desc);
670 
671 	banks = DIV_ROUND_UP(gpio->chip.ngpio, 32);
672 	for (i = 0; i < banks; i++) {
673 		const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i];
674 
675 		reg = ioread32(bank_reg(data, bank, reg_irq_status));
676 
677 		for_each_set_bit(p, &reg, 32) {
678 			girq = irq_find_mapping(gc->irq.domain, i * 32 + p);
679 			generic_handle_irq(girq);
680 		}
681 
682 	}
683 
684 	chained_irq_exit(ic, desc);
685 }
686 
687 static void aspeed_init_irq_valid_mask(struct gpio_chip *gc,
688 				       unsigned long *valid_mask,
689 				       unsigned int ngpios)
690 {
691 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
692 	const struct aspeed_bank_props *props = gpio->config->props;
693 
694 	while (!is_bank_props_sentinel(props)) {
695 		unsigned int offset;
696 		const unsigned long int input = props->input;
697 
698 		/* Pretty crummy approach, but similar to GPIO core */
699 		for_each_clear_bit(offset, &input, 32) {
700 			unsigned int i = props->bank * 32 + offset;
701 
702 			if (i >= gpio->chip.ngpio)
703 				break;
704 
705 			clear_bit(i, valid_mask);
706 		}
707 
708 		props++;
709 	}
710 }
711 
712 static int aspeed_gpio_reset_tolerance(struct gpio_chip *chip,
713 					unsigned int offset, bool enable)
714 {
715 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
716 	unsigned long flags;
717 	void __iomem *treg;
718 	bool copro;
719 	u32 val;
720 
721 	treg = bank_reg(gpio, to_bank(offset), reg_tolerance);
722 
723 	spin_lock_irqsave(&gpio->lock, flags);
724 	copro = aspeed_gpio_copro_request(gpio, offset);
725 
726 	val = readl(treg);
727 
728 	if (enable)
729 		val |= GPIO_BIT(offset);
730 	else
731 		val &= ~GPIO_BIT(offset);
732 
733 	writel(val, treg);
734 
735 	if (copro)
736 		aspeed_gpio_copro_release(gpio, offset);
737 	spin_unlock_irqrestore(&gpio->lock, flags);
738 
739 	return 0;
740 }
741 
742 static int aspeed_gpio_request(struct gpio_chip *chip, unsigned int offset)
743 {
744 	if (!have_gpio(gpiochip_get_data(chip), offset))
745 		return -ENODEV;
746 
747 	return pinctrl_gpio_request(chip->base + offset);
748 }
749 
750 static void aspeed_gpio_free(struct gpio_chip *chip, unsigned int offset)
751 {
752 	pinctrl_gpio_free(chip->base + offset);
753 }
754 
755 static int usecs_to_cycles(struct aspeed_gpio *gpio, unsigned long usecs,
756 		u32 *cycles)
757 {
758 	u64 rate;
759 	u64 n;
760 	u32 r;
761 
762 	rate = clk_get_rate(gpio->clk);
763 	if (!rate)
764 		return -ENOTSUPP;
765 
766 	n = rate * usecs;
767 	r = do_div(n, 1000000);
768 
769 	if (n >= U32_MAX)
770 		return -ERANGE;
771 
772 	/* At least as long as the requested time */
773 	*cycles = n + (!!r);
774 
775 	return 0;
776 }
777 
778 /* Call under gpio->lock */
779 static int register_allocated_timer(struct aspeed_gpio *gpio,
780 		unsigned int offset, unsigned int timer)
781 {
782 	if (WARN(gpio->offset_timer[offset] != 0,
783 				"Offset %d already allocated timer %d\n",
784 				offset, gpio->offset_timer[offset]))
785 		return -EINVAL;
786 
787 	if (WARN(gpio->timer_users[timer] == UINT_MAX,
788 				"Timer user count would overflow\n"))
789 		return -EPERM;
790 
791 	gpio->offset_timer[offset] = timer;
792 	gpio->timer_users[timer]++;
793 
794 	return 0;
795 }
796 
797 /* Call under gpio->lock */
798 static int unregister_allocated_timer(struct aspeed_gpio *gpio,
799 		unsigned int offset)
800 {
801 	if (WARN(gpio->offset_timer[offset] == 0,
802 				"No timer allocated to offset %d\n", offset))
803 		return -EINVAL;
804 
805 	if (WARN(gpio->timer_users[gpio->offset_timer[offset]] == 0,
806 				"No users recorded for timer %d\n",
807 				gpio->offset_timer[offset]))
808 		return -EINVAL;
809 
810 	gpio->timer_users[gpio->offset_timer[offset]]--;
811 	gpio->offset_timer[offset] = 0;
812 
813 	return 0;
814 }
815 
816 /* Call under gpio->lock */
817 static inline bool timer_allocation_registered(struct aspeed_gpio *gpio,
818 		unsigned int offset)
819 {
820 	return gpio->offset_timer[offset] > 0;
821 }
822 
823 /* Call under gpio->lock */
824 static void configure_timer(struct aspeed_gpio *gpio, unsigned int offset,
825 		unsigned int timer)
826 {
827 	const struct aspeed_gpio_bank *bank = to_bank(offset);
828 	const u32 mask = GPIO_BIT(offset);
829 	void __iomem *addr;
830 	u32 val;
831 
832 	/* Note: Debounce timer isn't under control of the command
833 	 * source registers, so no need to sync with the coprocessor
834 	 */
835 	addr = bank_reg(gpio, bank, reg_debounce_sel1);
836 	val = ioread32(addr);
837 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE1(timer, offset), addr);
838 
839 	addr = bank_reg(gpio, bank, reg_debounce_sel2);
840 	val = ioread32(addr);
841 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE2(timer, offset), addr);
842 }
843 
844 static int enable_debounce(struct gpio_chip *chip, unsigned int offset,
845 				    unsigned long usecs)
846 {
847 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
848 	u32 requested_cycles;
849 	unsigned long flags;
850 	int rc;
851 	int i;
852 
853 	if (!gpio->clk)
854 		return -EINVAL;
855 
856 	rc = usecs_to_cycles(gpio, usecs, &requested_cycles);
857 	if (rc < 0) {
858 		dev_warn(chip->parent, "Failed to convert %luus to cycles at %luHz: %d\n",
859 				usecs, clk_get_rate(gpio->clk), rc);
860 		return rc;
861 	}
862 
863 	spin_lock_irqsave(&gpio->lock, flags);
864 
865 	if (timer_allocation_registered(gpio, offset)) {
866 		rc = unregister_allocated_timer(gpio, offset);
867 		if (rc < 0)
868 			goto out;
869 	}
870 
871 	/* Try to find a timer already configured for the debounce period */
872 	for (i = 1; i < ARRAY_SIZE(debounce_timers); i++) {
873 		u32 cycles;
874 
875 		cycles = ioread32(gpio->base + debounce_timers[i]);
876 		if (requested_cycles == cycles)
877 			break;
878 	}
879 
880 	if (i == ARRAY_SIZE(debounce_timers)) {
881 		int j;
882 
883 		/*
884 		 * As there are no timers configured for the requested debounce
885 		 * period, find an unused timer instead
886 		 */
887 		for (j = 1; j < ARRAY_SIZE(gpio->timer_users); j++) {
888 			if (gpio->timer_users[j] == 0)
889 				break;
890 		}
891 
892 		if (j == ARRAY_SIZE(gpio->timer_users)) {
893 			dev_warn(chip->parent,
894 					"Debounce timers exhausted, cannot debounce for period %luus\n",
895 					usecs);
896 
897 			rc = -EPERM;
898 
899 			/*
900 			 * We already adjusted the accounting to remove @offset
901 			 * as a user of its previous timer, so also configure
902 			 * the hardware so @offset has timers disabled for
903 			 * consistency.
904 			 */
905 			configure_timer(gpio, offset, 0);
906 			goto out;
907 		}
908 
909 		i = j;
910 
911 		iowrite32(requested_cycles, gpio->base + debounce_timers[i]);
912 	}
913 
914 	if (WARN(i == 0, "Cannot register index of disabled timer\n")) {
915 		rc = -EINVAL;
916 		goto out;
917 	}
918 
919 	register_allocated_timer(gpio, offset, i);
920 	configure_timer(gpio, offset, i);
921 
922 out:
923 	spin_unlock_irqrestore(&gpio->lock, flags);
924 
925 	return rc;
926 }
927 
928 static int disable_debounce(struct gpio_chip *chip, unsigned int offset)
929 {
930 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
931 	unsigned long flags;
932 	int rc;
933 
934 	spin_lock_irqsave(&gpio->lock, flags);
935 
936 	rc = unregister_allocated_timer(gpio, offset);
937 	if (!rc)
938 		configure_timer(gpio, offset, 0);
939 
940 	spin_unlock_irqrestore(&gpio->lock, flags);
941 
942 	return rc;
943 }
944 
945 static int set_debounce(struct gpio_chip *chip, unsigned int offset,
946 				    unsigned long usecs)
947 {
948 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
949 
950 	if (!have_debounce(gpio, offset))
951 		return -ENOTSUPP;
952 
953 	if (usecs)
954 		return enable_debounce(chip, offset, usecs);
955 
956 	return disable_debounce(chip, offset);
957 }
958 
959 static int aspeed_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
960 				  unsigned long config)
961 {
962 	unsigned long param = pinconf_to_config_param(config);
963 	u32 arg = pinconf_to_config_argument(config);
964 
965 	if (param == PIN_CONFIG_INPUT_DEBOUNCE)
966 		return set_debounce(chip, offset, arg);
967 	else if (param == PIN_CONFIG_BIAS_DISABLE ||
968 			param == PIN_CONFIG_BIAS_PULL_DOWN ||
969 			param == PIN_CONFIG_DRIVE_STRENGTH)
970 		return pinctrl_gpio_set_config(offset, config);
971 	else if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN ||
972 			param == PIN_CONFIG_DRIVE_OPEN_SOURCE)
973 		/* Return -ENOTSUPP to trigger emulation, as per datasheet */
974 		return -ENOTSUPP;
975 	else if (param == PIN_CONFIG_PERSIST_STATE)
976 		return aspeed_gpio_reset_tolerance(chip, offset, arg);
977 
978 	return -ENOTSUPP;
979 }
980 
981 /**
982  * aspeed_gpio_copro_set_ops - Sets the callbacks used for handhsaking with
983  *                             the coprocessor for shared GPIO banks
984  * @ops: The callbacks
985  * @data: Pointer passed back to the callbacks
986  */
987 int aspeed_gpio_copro_set_ops(const struct aspeed_gpio_copro_ops *ops, void *data)
988 {
989 	copro_data = data;
990 	copro_ops = ops;
991 
992 	return 0;
993 }
994 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_set_ops);
995 
996 /**
997  * aspeed_gpio_copro_grab_gpio - Mark a GPIO used by the coprocessor. The entire
998  *                               bank gets marked and any access from the ARM will
999  *                               result in handshaking via callbacks.
1000  * @desc: The GPIO to be marked
1001  * @vreg_offset: If non-NULL, returns the value register offset in the GPIO space
1002  * @dreg_offset: If non-NULL, returns the data latch register offset in the GPIO space
1003  * @bit: If non-NULL, returns the bit number of the GPIO in the registers
1004  */
1005 int aspeed_gpio_copro_grab_gpio(struct gpio_desc *desc,
1006 				u16 *vreg_offset, u16 *dreg_offset, u8 *bit)
1007 {
1008 	struct gpio_chip *chip = gpiod_to_chip(desc);
1009 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
1010 	int rc = 0, bindex, offset = gpio_chip_hwgpio(desc);
1011 	const struct aspeed_gpio_bank *bank = to_bank(offset);
1012 	unsigned long flags;
1013 
1014 	if (!gpio->cf_copro_bankmap)
1015 		gpio->cf_copro_bankmap = kzalloc(gpio->chip.ngpio >> 3, GFP_KERNEL);
1016 	if (!gpio->cf_copro_bankmap)
1017 		return -ENOMEM;
1018 	if (offset < 0 || offset > gpio->chip.ngpio)
1019 		return -EINVAL;
1020 	bindex = offset >> 3;
1021 
1022 	spin_lock_irqsave(&gpio->lock, flags);
1023 
1024 	/* Sanity check, this shouldn't happen */
1025 	if (gpio->cf_copro_bankmap[bindex] == 0xff) {
1026 		rc = -EIO;
1027 		goto bail;
1028 	}
1029 	gpio->cf_copro_bankmap[bindex]++;
1030 
1031 	/* Switch command source */
1032 	if (gpio->cf_copro_bankmap[bindex] == 1)
1033 		aspeed_gpio_change_cmd_source(gpio, bank, bindex,
1034 					      GPIO_CMDSRC_COLDFIRE);
1035 
1036 	if (vreg_offset)
1037 		*vreg_offset = bank->val_regs;
1038 	if (dreg_offset)
1039 		*dreg_offset = bank->rdata_reg;
1040 	if (bit)
1041 		*bit = GPIO_OFFSET(offset);
1042  bail:
1043 	spin_unlock_irqrestore(&gpio->lock, flags);
1044 	return rc;
1045 }
1046 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_grab_gpio);
1047 
1048 /**
1049  * aspeed_gpio_copro_release_gpio - Unmark a GPIO used by the coprocessor.
1050  * @desc: The GPIO to be marked
1051  */
1052 int aspeed_gpio_copro_release_gpio(struct gpio_desc *desc)
1053 {
1054 	struct gpio_chip *chip = gpiod_to_chip(desc);
1055 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
1056 	int rc = 0, bindex, offset = gpio_chip_hwgpio(desc);
1057 	const struct aspeed_gpio_bank *bank = to_bank(offset);
1058 	unsigned long flags;
1059 
1060 	if (!gpio->cf_copro_bankmap)
1061 		return -ENXIO;
1062 
1063 	if (offset < 0 || offset > gpio->chip.ngpio)
1064 		return -EINVAL;
1065 	bindex = offset >> 3;
1066 
1067 	spin_lock_irqsave(&gpio->lock, flags);
1068 
1069 	/* Sanity check, this shouldn't happen */
1070 	if (gpio->cf_copro_bankmap[bindex] == 0) {
1071 		rc = -EIO;
1072 		goto bail;
1073 	}
1074 	gpio->cf_copro_bankmap[bindex]--;
1075 
1076 	/* Switch command source */
1077 	if (gpio->cf_copro_bankmap[bindex] == 0)
1078 		aspeed_gpio_change_cmd_source(gpio, bank, bindex,
1079 					      GPIO_CMDSRC_ARM);
1080  bail:
1081 	spin_unlock_irqrestore(&gpio->lock, flags);
1082 	return rc;
1083 }
1084 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_release_gpio);
1085 
1086 /*
1087  * Any banks not specified in a struct aspeed_bank_props array are assumed to
1088  * have the properties:
1089  *
1090  *     { .input = 0xffffffff, .output = 0xffffffff }
1091  */
1092 
1093 static const struct aspeed_bank_props ast2400_bank_props[] = {
1094 	/*     input	  output   */
1095 	{ 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
1096 	{ 6, 0x0000000f, 0x0fffff0f }, /* Y/Z/AA/AB, two 4-GPIO holes */
1097 	{ },
1098 };
1099 
1100 static const struct aspeed_gpio_config ast2400_config =
1101 	/* 220 for simplicity, really 216 with two 4-GPIO holes, four at end */
1102 	{ .nr_gpios = 220, .props = ast2400_bank_props, };
1103 
1104 static const struct aspeed_bank_props ast2500_bank_props[] = {
1105 	/*     input	  output   */
1106 	{ 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
1107 	{ 6, 0x0fffffff, 0x0fffffff }, /* Y/Z/AA/AB, 4-GPIO hole */
1108 	{ 7, 0x000000ff, 0x000000ff }, /* AC */
1109 	{ },
1110 };
1111 
1112 static const struct aspeed_gpio_config ast2500_config =
1113 	/* 232 for simplicity, actual number is 228 (4-GPIO hole in GPIOAB) */
1114 	{ .nr_gpios = 232, .props = ast2500_bank_props, };
1115 
1116 static const struct aspeed_bank_props ast2600_bank_props[] = {
1117 	/*     input	  output   */
1118 	{5, 0xffffffff,  0x0000ffff}, /* U/V/W/X */
1119 	{6, 0xffff0000,  0x0fff0000}, /* Y/Z */
1120 	{ },
1121 };
1122 
1123 static const struct aspeed_gpio_config ast2600_config =
1124 	/*
1125 	 * ast2600 has two controllers one with 208 GPIOs and one with 36 GPIOs.
1126 	 * We expect ngpio being set in the device tree and this is a fallback
1127 	 * option.
1128 	 */
1129 	{ .nr_gpios = 208, .props = ast2600_bank_props, };
1130 
1131 static const struct of_device_id aspeed_gpio_of_table[] = {
1132 	{ .compatible = "aspeed,ast2400-gpio", .data = &ast2400_config, },
1133 	{ .compatible = "aspeed,ast2500-gpio", .data = &ast2500_config, },
1134 	{ .compatible = "aspeed,ast2600-gpio", .data = &ast2600_config, },
1135 	{}
1136 };
1137 MODULE_DEVICE_TABLE(of, aspeed_gpio_of_table);
1138 
1139 static int __init aspeed_gpio_probe(struct platform_device *pdev)
1140 {
1141 	const struct of_device_id *gpio_id;
1142 	struct aspeed_gpio *gpio;
1143 	int rc, i, banks, err;
1144 	u32 ngpio;
1145 
1146 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
1147 	if (!gpio)
1148 		return -ENOMEM;
1149 
1150 	gpio->base = devm_platform_ioremap_resource(pdev, 0);
1151 	if (IS_ERR(gpio->base))
1152 		return PTR_ERR(gpio->base);
1153 
1154 	spin_lock_init(&gpio->lock);
1155 
1156 	gpio_id = of_match_node(aspeed_gpio_of_table, pdev->dev.of_node);
1157 	if (!gpio_id)
1158 		return -EINVAL;
1159 
1160 	gpio->clk = of_clk_get(pdev->dev.of_node, 0);
1161 	if (IS_ERR(gpio->clk)) {
1162 		dev_warn(&pdev->dev,
1163 				"Failed to get clock from devicetree, debouncing disabled\n");
1164 		gpio->clk = NULL;
1165 	}
1166 
1167 	gpio->config = gpio_id->data;
1168 
1169 	gpio->chip.parent = &pdev->dev;
1170 	err = of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpio);
1171 	gpio->chip.ngpio = (u16) ngpio;
1172 	if (err)
1173 		gpio->chip.ngpio = gpio->config->nr_gpios;
1174 	gpio->chip.direction_input = aspeed_gpio_dir_in;
1175 	gpio->chip.direction_output = aspeed_gpio_dir_out;
1176 	gpio->chip.get_direction = aspeed_gpio_get_direction;
1177 	gpio->chip.request = aspeed_gpio_request;
1178 	gpio->chip.free = aspeed_gpio_free;
1179 	gpio->chip.get = aspeed_gpio_get;
1180 	gpio->chip.set = aspeed_gpio_set;
1181 	gpio->chip.set_config = aspeed_gpio_set_config;
1182 	gpio->chip.label = dev_name(&pdev->dev);
1183 	gpio->chip.base = -1;
1184 
1185 	/* Allocate a cache of the output registers */
1186 	banks = DIV_ROUND_UP(gpio->chip.ngpio, 32);
1187 	gpio->dcache = devm_kcalloc(&pdev->dev,
1188 				    banks, sizeof(u32), GFP_KERNEL);
1189 	if (!gpio->dcache)
1190 		return -ENOMEM;
1191 
1192 	/*
1193 	 * Populate it with initial values read from the HW and switch
1194 	 * all command sources to the ARM by default
1195 	 */
1196 	for (i = 0; i < banks; i++) {
1197 		const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i];
1198 		void __iomem *addr = bank_reg(gpio, bank, reg_rdata);
1199 		gpio->dcache[i] = ioread32(addr);
1200 		aspeed_gpio_change_cmd_source(gpio, bank, 0, GPIO_CMDSRC_ARM);
1201 		aspeed_gpio_change_cmd_source(gpio, bank, 1, GPIO_CMDSRC_ARM);
1202 		aspeed_gpio_change_cmd_source(gpio, bank, 2, GPIO_CMDSRC_ARM);
1203 		aspeed_gpio_change_cmd_source(gpio, bank, 3, GPIO_CMDSRC_ARM);
1204 	}
1205 
1206 	/* Optionally set up an irqchip if there is an IRQ */
1207 	rc = platform_get_irq(pdev, 0);
1208 	if (rc > 0) {
1209 		struct gpio_irq_chip *girq;
1210 
1211 		gpio->irq = rc;
1212 		girq = &gpio->chip.irq;
1213 		girq->chip = &gpio->irqc;
1214 		girq->chip->name = dev_name(&pdev->dev);
1215 		girq->chip->irq_ack = aspeed_gpio_irq_ack;
1216 		girq->chip->irq_mask = aspeed_gpio_irq_mask;
1217 		girq->chip->irq_unmask = aspeed_gpio_irq_unmask;
1218 		girq->chip->irq_set_type = aspeed_gpio_set_type;
1219 		girq->parent_handler = aspeed_gpio_irq_handler;
1220 		girq->num_parents = 1;
1221 		girq->parents = devm_kcalloc(&pdev->dev, 1,
1222 					     sizeof(*girq->parents),
1223 					     GFP_KERNEL);
1224 		if (!girq->parents)
1225 			return -ENOMEM;
1226 		girq->parents[0] = gpio->irq;
1227 		girq->default_type = IRQ_TYPE_NONE;
1228 		girq->handler = handle_bad_irq;
1229 		girq->init_valid_mask = aspeed_init_irq_valid_mask;
1230 	}
1231 
1232 	gpio->offset_timer =
1233 		devm_kzalloc(&pdev->dev, gpio->chip.ngpio, GFP_KERNEL);
1234 	if (!gpio->offset_timer)
1235 		return -ENOMEM;
1236 
1237 	rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
1238 	if (rc < 0)
1239 		return rc;
1240 
1241 	return 0;
1242 }
1243 
1244 static struct platform_driver aspeed_gpio_driver = {
1245 	.driver = {
1246 		.name = KBUILD_MODNAME,
1247 		.of_match_table = aspeed_gpio_of_table,
1248 	},
1249 };
1250 
1251 module_platform_driver_probe(aspeed_gpio_driver, aspeed_gpio_probe);
1252 
1253 MODULE_DESCRIPTION("Aspeed GPIO Driver");
1254 MODULE_LICENSE("GPL");
1255