xref: /openbmc/linux/drivers/gpio/gpio-aspeed.c (revision 287dcc2b)
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 <linux/clk.h>
9 #include <linux/gpio/aspeed.h>
10 #include <linux/gpio/driver.h>
11 #include <linux/hashtable.h>
12 #include <linux/init.h>
13 #include <linux/io.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/pinctrl/consumer.h>
17 #include <linux/platform_device.h>
18 #include <linux/spinlock.h>
19 #include <linux/string.h>
20 
21 #include <asm/div64.h>
22 
23 /*
24  * These two headers aren't meant to be used by GPIO drivers. We need
25  * them in order to access gpio_chip_hwgpio() which we need to implement
26  * the aspeed specific API which allows the coprocessor to request
27  * access to some GPIOs and to arbitrate between coprocessor and ARM.
28  */
29 #include <linux/gpio/consumer.h>
30 #include "gpiolib.h"
31 
32 struct aspeed_bank_props {
33 	unsigned int bank;
34 	u32 input;
35 	u32 output;
36 };
37 
38 struct aspeed_gpio_config {
39 	unsigned int nr_gpios;
40 	const struct aspeed_bank_props *props;
41 };
42 
43 /*
44  * @offset_timer: Maps an offset to an @timer_users index, or zero if disabled
45  * @timer_users: Tracks the number of users for each timer
46  *
47  * The @timer_users has four elements but the first element is unused. This is
48  * to simplify accounting and indexing, as a zero value in @offset_timer
49  * represents disabled debouncing for the GPIO. Any other value for an element
50  * of @offset_timer is used as an index into @timer_users. This behaviour of
51  * the zero value aligns with the behaviour of zero built from the timer
52  * configuration registers (i.e. debouncing is disabled).
53  */
54 struct aspeed_gpio {
55 	struct gpio_chip chip;
56 	struct irq_chip irqc;
57 	raw_spinlock_t lock;
58 	void __iomem *base;
59 	int irq;
60 	const struct aspeed_gpio_config *config;
61 
62 	u8 *offset_timer;
63 	unsigned int timer_users[4];
64 	struct clk *clk;
65 
66 	u32 *dcache;
67 	u8 *cf_copro_bankmap;
68 };
69 
70 struct aspeed_gpio_bank {
71 	uint16_t	val_regs;	/* +0: Rd: read input value, Wr: set write latch
72 					 * +4: Rd/Wr: Direction (0=in, 1=out)
73 					 */
74 	uint16_t	rdata_reg;	/*     Rd: read write latch, Wr: <none>  */
75 	uint16_t	irq_regs;
76 	uint16_t	debounce_regs;
77 	uint16_t	tolerance_regs;
78 	uint16_t	cmdsrc_regs;
79 	const char	names[4][3];
80 };
81 
82 /*
83  * Note: The "value" register returns the input value sampled on the
84  *       line even when the GPIO is configured as an output. Since
85  *       that input goes through synchronizers, writing, then reading
86  *       back may not return the written value right away.
87  *
88  *       The "rdata" register returns the content of the write latch
89  *       and thus can be used to read back what was last written
90  *       reliably.
91  */
92 
93 static const int debounce_timers[4] = { 0x00, 0x50, 0x54, 0x58 };
94 
95 static const struct aspeed_gpio_copro_ops *copro_ops;
96 static void *copro_data;
97 
98 static const struct aspeed_gpio_bank aspeed_gpio_banks[] = {
99 	{
100 		.val_regs = 0x0000,
101 		.rdata_reg = 0x00c0,
102 		.irq_regs = 0x0008,
103 		.debounce_regs = 0x0040,
104 		.tolerance_regs = 0x001c,
105 		.cmdsrc_regs = 0x0060,
106 		.names = { "A", "B", "C", "D" },
107 	},
108 	{
109 		.val_regs = 0x0020,
110 		.rdata_reg = 0x00c4,
111 		.irq_regs = 0x0028,
112 		.debounce_regs = 0x0048,
113 		.tolerance_regs = 0x003c,
114 		.cmdsrc_regs = 0x0068,
115 		.names = { "E", "F", "G", "H" },
116 	},
117 	{
118 		.val_regs = 0x0070,
119 		.rdata_reg = 0x00c8,
120 		.irq_regs = 0x0098,
121 		.debounce_regs = 0x00b0,
122 		.tolerance_regs = 0x00ac,
123 		.cmdsrc_regs = 0x0090,
124 		.names = { "I", "J", "K", "L" },
125 	},
126 	{
127 		.val_regs = 0x0078,
128 		.rdata_reg = 0x00cc,
129 		.irq_regs = 0x00e8,
130 		.debounce_regs = 0x0100,
131 		.tolerance_regs = 0x00fc,
132 		.cmdsrc_regs = 0x00e0,
133 		.names = { "M", "N", "O", "P" },
134 	},
135 	{
136 		.val_regs = 0x0080,
137 		.rdata_reg = 0x00d0,
138 		.irq_regs = 0x0118,
139 		.debounce_regs = 0x0130,
140 		.tolerance_regs = 0x012c,
141 		.cmdsrc_regs = 0x0110,
142 		.names = { "Q", "R", "S", "T" },
143 	},
144 	{
145 		.val_regs = 0x0088,
146 		.rdata_reg = 0x00d4,
147 		.irq_regs = 0x0148,
148 		.debounce_regs = 0x0160,
149 		.tolerance_regs = 0x015c,
150 		.cmdsrc_regs = 0x0140,
151 		.names = { "U", "V", "W", "X" },
152 	},
153 	{
154 		.val_regs = 0x01E0,
155 		.rdata_reg = 0x00d8,
156 		.irq_regs = 0x0178,
157 		.debounce_regs = 0x0190,
158 		.tolerance_regs = 0x018c,
159 		.cmdsrc_regs = 0x0170,
160 		.names = { "Y", "Z", "AA", "AB" },
161 	},
162 	{
163 		.val_regs = 0x01e8,
164 		.rdata_reg = 0x00dc,
165 		.irq_regs = 0x01a8,
166 		.debounce_regs = 0x01c0,
167 		.tolerance_regs = 0x01bc,
168 		.cmdsrc_regs = 0x01a0,
169 		.names = { "AC", "", "", "" },
170 	},
171 };
172 
173 enum aspeed_gpio_reg {
174 	reg_val,
175 	reg_rdata,
176 	reg_dir,
177 	reg_irq_enable,
178 	reg_irq_type0,
179 	reg_irq_type1,
180 	reg_irq_type2,
181 	reg_irq_status,
182 	reg_debounce_sel1,
183 	reg_debounce_sel2,
184 	reg_tolerance,
185 	reg_cmdsrc0,
186 	reg_cmdsrc1,
187 };
188 
189 #define GPIO_VAL_VALUE	0x00
190 #define GPIO_VAL_DIR	0x04
191 
192 #define GPIO_IRQ_ENABLE	0x00
193 #define GPIO_IRQ_TYPE0	0x04
194 #define GPIO_IRQ_TYPE1	0x08
195 #define GPIO_IRQ_TYPE2	0x0c
196 #define GPIO_IRQ_STATUS	0x10
197 
198 #define GPIO_DEBOUNCE_SEL1 0x00
199 #define GPIO_DEBOUNCE_SEL2 0x04
200 
201 #define GPIO_CMDSRC_0	0x00
202 #define GPIO_CMDSRC_1	0x04
203 #define  GPIO_CMDSRC_ARM		0
204 #define  GPIO_CMDSRC_LPC		1
205 #define  GPIO_CMDSRC_COLDFIRE		2
206 #define  GPIO_CMDSRC_RESERVED		3
207 
208 /* This will be resolved at compile time */
209 static inline void __iomem *bank_reg(struct aspeed_gpio *gpio,
210 				     const struct aspeed_gpio_bank *bank,
211 				     const enum aspeed_gpio_reg reg)
212 {
213 	switch (reg) {
214 	case reg_val:
215 		return gpio->base + bank->val_regs + GPIO_VAL_VALUE;
216 	case reg_rdata:
217 		return gpio->base + bank->rdata_reg;
218 	case reg_dir:
219 		return gpio->base + bank->val_regs + GPIO_VAL_DIR;
220 	case reg_irq_enable:
221 		return gpio->base + bank->irq_regs + GPIO_IRQ_ENABLE;
222 	case reg_irq_type0:
223 		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE0;
224 	case reg_irq_type1:
225 		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE1;
226 	case reg_irq_type2:
227 		return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE2;
228 	case reg_irq_status:
229 		return gpio->base + bank->irq_regs + GPIO_IRQ_STATUS;
230 	case reg_debounce_sel1:
231 		return gpio->base + bank->debounce_regs + GPIO_DEBOUNCE_SEL1;
232 	case reg_debounce_sel2:
233 		return gpio->base + bank->debounce_regs + GPIO_DEBOUNCE_SEL2;
234 	case reg_tolerance:
235 		return gpio->base + bank->tolerance_regs;
236 	case reg_cmdsrc0:
237 		return gpio->base + bank->cmdsrc_regs + GPIO_CMDSRC_0;
238 	case reg_cmdsrc1:
239 		return gpio->base + bank->cmdsrc_regs + GPIO_CMDSRC_1;
240 	}
241 	BUG();
242 }
243 
244 #define GPIO_BANK(x)	((x) >> 5)
245 #define GPIO_OFFSET(x)	((x) & 0x1f)
246 #define GPIO_BIT(x)	BIT(GPIO_OFFSET(x))
247 
248 #define _GPIO_SET_DEBOUNCE(t, o, i) ((!!((t) & BIT(i))) << GPIO_OFFSET(o))
249 #define GPIO_SET_DEBOUNCE1(t, o) _GPIO_SET_DEBOUNCE(t, o, 1)
250 #define GPIO_SET_DEBOUNCE2(t, o) _GPIO_SET_DEBOUNCE(t, o, 0)
251 
252 static const struct aspeed_gpio_bank *to_bank(unsigned int offset)
253 {
254 	unsigned int bank = GPIO_BANK(offset);
255 
256 	WARN_ON(bank >= ARRAY_SIZE(aspeed_gpio_banks));
257 	return &aspeed_gpio_banks[bank];
258 }
259 
260 static inline bool is_bank_props_sentinel(const struct aspeed_bank_props *props)
261 {
262 	return !(props->input || props->output);
263 }
264 
265 static inline const struct aspeed_bank_props *find_bank_props(
266 		struct aspeed_gpio *gpio, unsigned int offset)
267 {
268 	const struct aspeed_bank_props *props = gpio->config->props;
269 
270 	while (!is_bank_props_sentinel(props)) {
271 		if (props->bank == GPIO_BANK(offset))
272 			return props;
273 		props++;
274 	}
275 
276 	return NULL;
277 }
278 
279 static inline bool have_gpio(struct aspeed_gpio *gpio, unsigned int offset)
280 {
281 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
282 	const struct aspeed_gpio_bank *bank = to_bank(offset);
283 	unsigned int group = GPIO_OFFSET(offset) / 8;
284 
285 	return bank->names[group][0] != '\0' &&
286 		(!props || ((props->input | props->output) & GPIO_BIT(offset)));
287 }
288 
289 static inline bool have_input(struct aspeed_gpio *gpio, unsigned int offset)
290 {
291 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
292 
293 	return !props || (props->input & GPIO_BIT(offset));
294 }
295 
296 #define have_irq(g, o) have_input((g), (o))
297 #define have_debounce(g, o) have_input((g), (o))
298 
299 static inline bool have_output(struct aspeed_gpio *gpio, unsigned int offset)
300 {
301 	const struct aspeed_bank_props *props = find_bank_props(gpio, offset);
302 
303 	return !props || (props->output & GPIO_BIT(offset));
304 }
305 
306 static void aspeed_gpio_change_cmd_source(struct aspeed_gpio *gpio,
307 					  const struct aspeed_gpio_bank *bank,
308 					  int bindex, int cmdsrc)
309 {
310 	void __iomem *c0 = bank_reg(gpio, bank, reg_cmdsrc0);
311 	void __iomem *c1 = bank_reg(gpio, bank, reg_cmdsrc1);
312 	u32 bit, reg;
313 
314 	/*
315 	 * Each register controls 4 banks, so take the bottom 2
316 	 * bits of the bank index, and use them to select the
317 	 * right control bit (0, 8, 16 or 24).
318 	 */
319 	bit = BIT((bindex & 3) << 3);
320 
321 	/* Source 1 first to avoid illegal 11 combination */
322 	reg = ioread32(c1);
323 	if (cmdsrc & 2)
324 		reg |= bit;
325 	else
326 		reg &= ~bit;
327 	iowrite32(reg, c1);
328 
329 	/* Then Source 0 */
330 	reg = ioread32(c0);
331 	if (cmdsrc & 1)
332 		reg |= bit;
333 	else
334 		reg &= ~bit;
335 	iowrite32(reg, c0);
336 }
337 
338 static bool aspeed_gpio_copro_request(struct aspeed_gpio *gpio,
339 				      unsigned int offset)
340 {
341 	const struct aspeed_gpio_bank *bank = to_bank(offset);
342 
343 	if (!copro_ops || !gpio->cf_copro_bankmap)
344 		return false;
345 	if (!gpio->cf_copro_bankmap[offset >> 3])
346 		return false;
347 	if (!copro_ops->request_access)
348 		return false;
349 
350 	/* Pause the coprocessor */
351 	copro_ops->request_access(copro_data);
352 
353 	/* Change command source back to ARM */
354 	aspeed_gpio_change_cmd_source(gpio, bank, offset >> 3, GPIO_CMDSRC_ARM);
355 
356 	/* Update cache */
357 	gpio->dcache[GPIO_BANK(offset)] = ioread32(bank_reg(gpio, bank, reg_rdata));
358 
359 	return true;
360 }
361 
362 static void aspeed_gpio_copro_release(struct aspeed_gpio *gpio,
363 				      unsigned int offset)
364 {
365 	const struct aspeed_gpio_bank *bank = to_bank(offset);
366 
367 	if (!copro_ops || !gpio->cf_copro_bankmap)
368 		return;
369 	if (!gpio->cf_copro_bankmap[offset >> 3])
370 		return;
371 	if (!copro_ops->release_access)
372 		return;
373 
374 	/* Change command source back to ColdFire */
375 	aspeed_gpio_change_cmd_source(gpio, bank, offset >> 3,
376 				      GPIO_CMDSRC_COLDFIRE);
377 
378 	/* Restart the coprocessor */
379 	copro_ops->release_access(copro_data);
380 }
381 
382 static int aspeed_gpio_get(struct gpio_chip *gc, unsigned int offset)
383 {
384 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
385 	const struct aspeed_gpio_bank *bank = to_bank(offset);
386 
387 	return !!(ioread32(bank_reg(gpio, bank, reg_val)) & GPIO_BIT(offset));
388 }
389 
390 static void __aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
391 			      int val)
392 {
393 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
394 	const struct aspeed_gpio_bank *bank = to_bank(offset);
395 	void __iomem *addr;
396 	u32 reg;
397 
398 	addr = bank_reg(gpio, bank, reg_val);
399 	reg = gpio->dcache[GPIO_BANK(offset)];
400 
401 	if (val)
402 		reg |= GPIO_BIT(offset);
403 	else
404 		reg &= ~GPIO_BIT(offset);
405 	gpio->dcache[GPIO_BANK(offset)] = reg;
406 
407 	iowrite32(reg, addr);
408 }
409 
410 static void aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
411 			    int val)
412 {
413 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
414 	unsigned long flags;
415 	bool copro;
416 
417 	raw_spin_lock_irqsave(&gpio->lock, flags);
418 	copro = aspeed_gpio_copro_request(gpio, offset);
419 
420 	__aspeed_gpio_set(gc, offset, val);
421 
422 	if (copro)
423 		aspeed_gpio_copro_release(gpio, offset);
424 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
425 }
426 
427 static int aspeed_gpio_dir_in(struct gpio_chip *gc, unsigned int offset)
428 {
429 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
430 	const struct aspeed_gpio_bank *bank = to_bank(offset);
431 	void __iomem *addr = bank_reg(gpio, bank, reg_dir);
432 	unsigned long flags;
433 	bool copro;
434 	u32 reg;
435 
436 	if (!have_input(gpio, offset))
437 		return -ENOTSUPP;
438 
439 	raw_spin_lock_irqsave(&gpio->lock, flags);
440 
441 	reg = ioread32(addr);
442 	reg &= ~GPIO_BIT(offset);
443 
444 	copro = aspeed_gpio_copro_request(gpio, offset);
445 	iowrite32(reg, addr);
446 	if (copro)
447 		aspeed_gpio_copro_release(gpio, offset);
448 
449 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
450 
451 	return 0;
452 }
453 
454 static int aspeed_gpio_dir_out(struct gpio_chip *gc,
455 			       unsigned int offset, int val)
456 {
457 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
458 	const struct aspeed_gpio_bank *bank = to_bank(offset);
459 	void __iomem *addr = bank_reg(gpio, bank, reg_dir);
460 	unsigned long flags;
461 	bool copro;
462 	u32 reg;
463 
464 	if (!have_output(gpio, offset))
465 		return -ENOTSUPP;
466 
467 	raw_spin_lock_irqsave(&gpio->lock, flags);
468 
469 	reg = ioread32(addr);
470 	reg |= GPIO_BIT(offset);
471 
472 	copro = aspeed_gpio_copro_request(gpio, offset);
473 	__aspeed_gpio_set(gc, offset, val);
474 	iowrite32(reg, addr);
475 
476 	if (copro)
477 		aspeed_gpio_copro_release(gpio, offset);
478 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
479 
480 	return 0;
481 }
482 
483 static int aspeed_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
484 {
485 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
486 	const struct aspeed_gpio_bank *bank = to_bank(offset);
487 	unsigned long flags;
488 	u32 val;
489 
490 	if (!have_input(gpio, offset))
491 		return GPIO_LINE_DIRECTION_OUT;
492 
493 	if (!have_output(gpio, offset))
494 		return GPIO_LINE_DIRECTION_IN;
495 
496 	raw_spin_lock_irqsave(&gpio->lock, flags);
497 
498 	val = ioread32(bank_reg(gpio, bank, reg_dir)) & GPIO_BIT(offset);
499 
500 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
501 
502 	return val ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
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 	raw_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 	raw_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 	raw_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 	raw_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 		fallthrough;
616 	case IRQ_TYPE_EDGE_RISING:
617 		type0 |= bit;
618 		fallthrough;
619 	case IRQ_TYPE_EDGE_FALLING:
620 		handler = handle_edge_irq;
621 		break;
622 	case IRQ_TYPE_LEVEL_HIGH:
623 		type0 |= bit;
624 		fallthrough;
625 	case IRQ_TYPE_LEVEL_LOW:
626 		type1 |= bit;
627 		handler = handle_level_irq;
628 		break;
629 	default:
630 		return -EINVAL;
631 	}
632 
633 	raw_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 	raw_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, 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 			generic_handle_domain_irq(gc->irq.domain, i * 32 + p);
679 	}
680 
681 	chained_irq_exit(ic, desc);
682 }
683 
684 static void aspeed_init_irq_valid_mask(struct gpio_chip *gc,
685 				       unsigned long *valid_mask,
686 				       unsigned int ngpios)
687 {
688 	struct aspeed_gpio *gpio = gpiochip_get_data(gc);
689 	const struct aspeed_bank_props *props = gpio->config->props;
690 
691 	while (!is_bank_props_sentinel(props)) {
692 		unsigned int offset;
693 		const unsigned long int input = props->input;
694 
695 		/* Pretty crummy approach, but similar to GPIO core */
696 		for_each_clear_bit(offset, &input, 32) {
697 			unsigned int i = props->bank * 32 + offset;
698 
699 			if (i >= gpio->chip.ngpio)
700 				break;
701 
702 			clear_bit(i, valid_mask);
703 		}
704 
705 		props++;
706 	}
707 }
708 
709 static int aspeed_gpio_reset_tolerance(struct gpio_chip *chip,
710 					unsigned int offset, bool enable)
711 {
712 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
713 	unsigned long flags;
714 	void __iomem *treg;
715 	bool copro;
716 	u32 val;
717 
718 	treg = bank_reg(gpio, to_bank(offset), reg_tolerance);
719 
720 	raw_spin_lock_irqsave(&gpio->lock, flags);
721 	copro = aspeed_gpio_copro_request(gpio, offset);
722 
723 	val = readl(treg);
724 
725 	if (enable)
726 		val |= GPIO_BIT(offset);
727 	else
728 		val &= ~GPIO_BIT(offset);
729 
730 	writel(val, treg);
731 
732 	if (copro)
733 		aspeed_gpio_copro_release(gpio, offset);
734 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
735 
736 	return 0;
737 }
738 
739 static int aspeed_gpio_request(struct gpio_chip *chip, unsigned int offset)
740 {
741 	if (!have_gpio(gpiochip_get_data(chip), offset))
742 		return -ENODEV;
743 
744 	return pinctrl_gpio_request(chip->base + offset);
745 }
746 
747 static void aspeed_gpio_free(struct gpio_chip *chip, unsigned int offset)
748 {
749 	pinctrl_gpio_free(chip->base + offset);
750 }
751 
752 static int usecs_to_cycles(struct aspeed_gpio *gpio, unsigned long usecs,
753 		u32 *cycles)
754 {
755 	u64 rate;
756 	u64 n;
757 	u32 r;
758 
759 	rate = clk_get_rate(gpio->clk);
760 	if (!rate)
761 		return -ENOTSUPP;
762 
763 	n = rate * usecs;
764 	r = do_div(n, 1000000);
765 
766 	if (n >= U32_MAX)
767 		return -ERANGE;
768 
769 	/* At least as long as the requested time */
770 	*cycles = n + (!!r);
771 
772 	return 0;
773 }
774 
775 /* Call under gpio->lock */
776 static int register_allocated_timer(struct aspeed_gpio *gpio,
777 		unsigned int offset, unsigned int timer)
778 {
779 	if (WARN(gpio->offset_timer[offset] != 0,
780 				"Offset %d already allocated timer %d\n",
781 				offset, gpio->offset_timer[offset]))
782 		return -EINVAL;
783 
784 	if (WARN(gpio->timer_users[timer] == UINT_MAX,
785 				"Timer user count would overflow\n"))
786 		return -EPERM;
787 
788 	gpio->offset_timer[offset] = timer;
789 	gpio->timer_users[timer]++;
790 
791 	return 0;
792 }
793 
794 /* Call under gpio->lock */
795 static int unregister_allocated_timer(struct aspeed_gpio *gpio,
796 		unsigned int offset)
797 {
798 	if (WARN(gpio->offset_timer[offset] == 0,
799 				"No timer allocated to offset %d\n", offset))
800 		return -EINVAL;
801 
802 	if (WARN(gpio->timer_users[gpio->offset_timer[offset]] == 0,
803 				"No users recorded for timer %d\n",
804 				gpio->offset_timer[offset]))
805 		return -EINVAL;
806 
807 	gpio->timer_users[gpio->offset_timer[offset]]--;
808 	gpio->offset_timer[offset] = 0;
809 
810 	return 0;
811 }
812 
813 /* Call under gpio->lock */
814 static inline bool timer_allocation_registered(struct aspeed_gpio *gpio,
815 		unsigned int offset)
816 {
817 	return gpio->offset_timer[offset] > 0;
818 }
819 
820 /* Call under gpio->lock */
821 static void configure_timer(struct aspeed_gpio *gpio, unsigned int offset,
822 		unsigned int timer)
823 {
824 	const struct aspeed_gpio_bank *bank = to_bank(offset);
825 	const u32 mask = GPIO_BIT(offset);
826 	void __iomem *addr;
827 	u32 val;
828 
829 	/* Note: Debounce timer isn't under control of the command
830 	 * source registers, so no need to sync with the coprocessor
831 	 */
832 	addr = bank_reg(gpio, bank, reg_debounce_sel1);
833 	val = ioread32(addr);
834 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE1(timer, offset), addr);
835 
836 	addr = bank_reg(gpio, bank, reg_debounce_sel2);
837 	val = ioread32(addr);
838 	iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE2(timer, offset), addr);
839 }
840 
841 static int enable_debounce(struct gpio_chip *chip, unsigned int offset,
842 				    unsigned long usecs)
843 {
844 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
845 	u32 requested_cycles;
846 	unsigned long flags;
847 	int rc;
848 	int i;
849 
850 	if (!gpio->clk)
851 		return -EINVAL;
852 
853 	rc = usecs_to_cycles(gpio, usecs, &requested_cycles);
854 	if (rc < 0) {
855 		dev_warn(chip->parent, "Failed to convert %luus to cycles at %luHz: %d\n",
856 				usecs, clk_get_rate(gpio->clk), rc);
857 		return rc;
858 	}
859 
860 	raw_spin_lock_irqsave(&gpio->lock, flags);
861 
862 	if (timer_allocation_registered(gpio, offset)) {
863 		rc = unregister_allocated_timer(gpio, offset);
864 		if (rc < 0)
865 			goto out;
866 	}
867 
868 	/* Try to find a timer already configured for the debounce period */
869 	for (i = 1; i < ARRAY_SIZE(debounce_timers); i++) {
870 		u32 cycles;
871 
872 		cycles = ioread32(gpio->base + debounce_timers[i]);
873 		if (requested_cycles == cycles)
874 			break;
875 	}
876 
877 	if (i == ARRAY_SIZE(debounce_timers)) {
878 		int j;
879 
880 		/*
881 		 * As there are no timers configured for the requested debounce
882 		 * period, find an unused timer instead
883 		 */
884 		for (j = 1; j < ARRAY_SIZE(gpio->timer_users); j++) {
885 			if (gpio->timer_users[j] == 0)
886 				break;
887 		}
888 
889 		if (j == ARRAY_SIZE(gpio->timer_users)) {
890 			dev_warn(chip->parent,
891 					"Debounce timers exhausted, cannot debounce for period %luus\n",
892 					usecs);
893 
894 			rc = -EPERM;
895 
896 			/*
897 			 * We already adjusted the accounting to remove @offset
898 			 * as a user of its previous timer, so also configure
899 			 * the hardware so @offset has timers disabled for
900 			 * consistency.
901 			 */
902 			configure_timer(gpio, offset, 0);
903 			goto out;
904 		}
905 
906 		i = j;
907 
908 		iowrite32(requested_cycles, gpio->base + debounce_timers[i]);
909 	}
910 
911 	if (WARN(i == 0, "Cannot register index of disabled timer\n")) {
912 		rc = -EINVAL;
913 		goto out;
914 	}
915 
916 	register_allocated_timer(gpio, offset, i);
917 	configure_timer(gpio, offset, i);
918 
919 out:
920 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
921 
922 	return rc;
923 }
924 
925 static int disable_debounce(struct gpio_chip *chip, unsigned int offset)
926 {
927 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
928 	unsigned long flags;
929 	int rc;
930 
931 	raw_spin_lock_irqsave(&gpio->lock, flags);
932 
933 	rc = unregister_allocated_timer(gpio, offset);
934 	if (!rc)
935 		configure_timer(gpio, offset, 0);
936 
937 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
938 
939 	return rc;
940 }
941 
942 static int set_debounce(struct gpio_chip *chip, unsigned int offset,
943 				    unsigned long usecs)
944 {
945 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
946 
947 	if (!have_debounce(gpio, offset))
948 		return -ENOTSUPP;
949 
950 	if (usecs)
951 		return enable_debounce(chip, offset, usecs);
952 
953 	return disable_debounce(chip, offset);
954 }
955 
956 static int aspeed_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
957 				  unsigned long config)
958 {
959 	unsigned long param = pinconf_to_config_param(config);
960 	u32 arg = pinconf_to_config_argument(config);
961 
962 	if (param == PIN_CONFIG_INPUT_DEBOUNCE)
963 		return set_debounce(chip, offset, arg);
964 	else if (param == PIN_CONFIG_BIAS_DISABLE ||
965 			param == PIN_CONFIG_BIAS_PULL_DOWN ||
966 			param == PIN_CONFIG_DRIVE_STRENGTH)
967 		return pinctrl_gpio_set_config(offset, config);
968 	else if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN ||
969 			param == PIN_CONFIG_DRIVE_OPEN_SOURCE)
970 		/* Return -ENOTSUPP to trigger emulation, as per datasheet */
971 		return -ENOTSUPP;
972 	else if (param == PIN_CONFIG_PERSIST_STATE)
973 		return aspeed_gpio_reset_tolerance(chip, offset, arg);
974 
975 	return -ENOTSUPP;
976 }
977 
978 /**
979  * aspeed_gpio_copro_set_ops - Sets the callbacks used for handshaking with
980  *                             the coprocessor for shared GPIO banks
981  * @ops: The callbacks
982  * @data: Pointer passed back to the callbacks
983  */
984 int aspeed_gpio_copro_set_ops(const struct aspeed_gpio_copro_ops *ops, void *data)
985 {
986 	copro_data = data;
987 	copro_ops = ops;
988 
989 	return 0;
990 }
991 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_set_ops);
992 
993 /**
994  * aspeed_gpio_copro_grab_gpio - Mark a GPIO used by the coprocessor. The entire
995  *                               bank gets marked and any access from the ARM will
996  *                               result in handshaking via callbacks.
997  * @desc: The GPIO to be marked
998  * @vreg_offset: If non-NULL, returns the value register offset in the GPIO space
999  * @dreg_offset: If non-NULL, returns the data latch register offset in the GPIO space
1000  * @bit: If non-NULL, returns the bit number of the GPIO in the registers
1001  */
1002 int aspeed_gpio_copro_grab_gpio(struct gpio_desc *desc,
1003 				u16 *vreg_offset, u16 *dreg_offset, u8 *bit)
1004 {
1005 	struct gpio_chip *chip = gpiod_to_chip(desc);
1006 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
1007 	int rc = 0, bindex, offset = gpio_chip_hwgpio(desc);
1008 	const struct aspeed_gpio_bank *bank = to_bank(offset);
1009 	unsigned long flags;
1010 
1011 	if (!gpio->cf_copro_bankmap)
1012 		gpio->cf_copro_bankmap = kzalloc(gpio->chip.ngpio >> 3, GFP_KERNEL);
1013 	if (!gpio->cf_copro_bankmap)
1014 		return -ENOMEM;
1015 	if (offset < 0 || offset > gpio->chip.ngpio)
1016 		return -EINVAL;
1017 	bindex = offset >> 3;
1018 
1019 	raw_spin_lock_irqsave(&gpio->lock, flags);
1020 
1021 	/* Sanity check, this shouldn't happen */
1022 	if (gpio->cf_copro_bankmap[bindex] == 0xff) {
1023 		rc = -EIO;
1024 		goto bail;
1025 	}
1026 	gpio->cf_copro_bankmap[bindex]++;
1027 
1028 	/* Switch command source */
1029 	if (gpio->cf_copro_bankmap[bindex] == 1)
1030 		aspeed_gpio_change_cmd_source(gpio, bank, bindex,
1031 					      GPIO_CMDSRC_COLDFIRE);
1032 
1033 	if (vreg_offset)
1034 		*vreg_offset = bank->val_regs;
1035 	if (dreg_offset)
1036 		*dreg_offset = bank->rdata_reg;
1037 	if (bit)
1038 		*bit = GPIO_OFFSET(offset);
1039  bail:
1040 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
1041 	return rc;
1042 }
1043 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_grab_gpio);
1044 
1045 /**
1046  * aspeed_gpio_copro_release_gpio - Unmark a GPIO used by the coprocessor.
1047  * @desc: The GPIO to be marked
1048  */
1049 int aspeed_gpio_copro_release_gpio(struct gpio_desc *desc)
1050 {
1051 	struct gpio_chip *chip = gpiod_to_chip(desc);
1052 	struct aspeed_gpio *gpio = gpiochip_get_data(chip);
1053 	int rc = 0, bindex, offset = gpio_chip_hwgpio(desc);
1054 	const struct aspeed_gpio_bank *bank = to_bank(offset);
1055 	unsigned long flags;
1056 
1057 	if (!gpio->cf_copro_bankmap)
1058 		return -ENXIO;
1059 
1060 	if (offset < 0 || offset > gpio->chip.ngpio)
1061 		return -EINVAL;
1062 	bindex = offset >> 3;
1063 
1064 	raw_spin_lock_irqsave(&gpio->lock, flags);
1065 
1066 	/* Sanity check, this shouldn't happen */
1067 	if (gpio->cf_copro_bankmap[bindex] == 0) {
1068 		rc = -EIO;
1069 		goto bail;
1070 	}
1071 	gpio->cf_copro_bankmap[bindex]--;
1072 
1073 	/* Switch command source */
1074 	if (gpio->cf_copro_bankmap[bindex] == 0)
1075 		aspeed_gpio_change_cmd_source(gpio, bank, bindex,
1076 					      GPIO_CMDSRC_ARM);
1077  bail:
1078 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
1079 	return rc;
1080 }
1081 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_release_gpio);
1082 
1083 /*
1084  * Any banks not specified in a struct aspeed_bank_props array are assumed to
1085  * have the properties:
1086  *
1087  *     { .input = 0xffffffff, .output = 0xffffffff }
1088  */
1089 
1090 static const struct aspeed_bank_props ast2400_bank_props[] = {
1091 	/*     input	  output   */
1092 	{ 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
1093 	{ 6, 0x0000000f, 0x0fffff0f }, /* Y/Z/AA/AB, two 4-GPIO holes */
1094 	{ },
1095 };
1096 
1097 static const struct aspeed_gpio_config ast2400_config =
1098 	/* 220 for simplicity, really 216 with two 4-GPIO holes, four at end */
1099 	{ .nr_gpios = 220, .props = ast2400_bank_props, };
1100 
1101 static const struct aspeed_bank_props ast2500_bank_props[] = {
1102 	/*     input	  output   */
1103 	{ 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */
1104 	{ 6, 0x0fffffff, 0x0fffffff }, /* Y/Z/AA/AB, 4-GPIO hole */
1105 	{ 7, 0x000000ff, 0x000000ff }, /* AC */
1106 	{ },
1107 };
1108 
1109 static const struct aspeed_gpio_config ast2500_config =
1110 	/* 232 for simplicity, actual number is 228 (4-GPIO hole in GPIOAB) */
1111 	{ .nr_gpios = 232, .props = ast2500_bank_props, };
1112 
1113 static const struct aspeed_bank_props ast2600_bank_props[] = {
1114 	/*     input	  output   */
1115 	{4, 0xffffffff,  0x00ffffff}, /* Q/R/S/T */
1116 	{5, 0xffffffff,  0xffffff00}, /* U/V/W/X */
1117 	{6, 0x0000ffff,  0x0000ffff}, /* Y/Z */
1118 	{ },
1119 };
1120 
1121 static const struct aspeed_gpio_config ast2600_config =
1122 	/*
1123 	 * ast2600 has two controllers one with 208 GPIOs and one with 36 GPIOs.
1124 	 * We expect ngpio being set in the device tree and this is a fallback
1125 	 * option.
1126 	 */
1127 	{ .nr_gpios = 208, .props = ast2600_bank_props, };
1128 
1129 static const struct of_device_id aspeed_gpio_of_table[] = {
1130 	{ .compatible = "aspeed,ast2400-gpio", .data = &ast2400_config, },
1131 	{ .compatible = "aspeed,ast2500-gpio", .data = &ast2500_config, },
1132 	{ .compatible = "aspeed,ast2600-gpio", .data = &ast2600_config, },
1133 	{}
1134 };
1135 MODULE_DEVICE_TABLE(of, aspeed_gpio_of_table);
1136 
1137 static int __init aspeed_gpio_probe(struct platform_device *pdev)
1138 {
1139 	const struct of_device_id *gpio_id;
1140 	struct aspeed_gpio *gpio;
1141 	int rc, i, banks, err;
1142 	u32 ngpio;
1143 
1144 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
1145 	if (!gpio)
1146 		return -ENOMEM;
1147 
1148 	gpio->base = devm_platform_ioremap_resource(pdev, 0);
1149 	if (IS_ERR(gpio->base))
1150 		return PTR_ERR(gpio->base);
1151 
1152 	raw_spin_lock_init(&gpio->lock);
1153 
1154 	gpio_id = of_match_node(aspeed_gpio_of_table, pdev->dev.of_node);
1155 	if (!gpio_id)
1156 		return -EINVAL;
1157 
1158 	gpio->clk = of_clk_get(pdev->dev.of_node, 0);
1159 	if (IS_ERR(gpio->clk)) {
1160 		dev_warn(&pdev->dev,
1161 				"Failed to get clock from devicetree, debouncing disabled\n");
1162 		gpio->clk = NULL;
1163 	}
1164 
1165 	gpio->config = gpio_id->data;
1166 
1167 	gpio->chip.parent = &pdev->dev;
1168 	err = of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpio);
1169 	gpio->chip.ngpio = (u16) ngpio;
1170 	if (err)
1171 		gpio->chip.ngpio = gpio->config->nr_gpios;
1172 	gpio->chip.direction_input = aspeed_gpio_dir_in;
1173 	gpio->chip.direction_output = aspeed_gpio_dir_out;
1174 	gpio->chip.get_direction = aspeed_gpio_get_direction;
1175 	gpio->chip.request = aspeed_gpio_request;
1176 	gpio->chip.free = aspeed_gpio_free;
1177 	gpio->chip.get = aspeed_gpio_get;
1178 	gpio->chip.set = aspeed_gpio_set;
1179 	gpio->chip.set_config = aspeed_gpio_set_config;
1180 	gpio->chip.label = dev_name(&pdev->dev);
1181 	gpio->chip.base = -1;
1182 
1183 	/* Allocate a cache of the output registers */
1184 	banks = DIV_ROUND_UP(gpio->chip.ngpio, 32);
1185 	gpio->dcache = devm_kcalloc(&pdev->dev,
1186 				    banks, sizeof(u32), GFP_KERNEL);
1187 	if (!gpio->dcache)
1188 		return -ENOMEM;
1189 
1190 	/*
1191 	 * Populate it with initial values read from the HW and switch
1192 	 * all command sources to the ARM by default
1193 	 */
1194 	for (i = 0; i < banks; i++) {
1195 		const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i];
1196 		void __iomem *addr = bank_reg(gpio, bank, reg_rdata);
1197 		gpio->dcache[i] = ioread32(addr);
1198 		aspeed_gpio_change_cmd_source(gpio, bank, 0, GPIO_CMDSRC_ARM);
1199 		aspeed_gpio_change_cmd_source(gpio, bank, 1, GPIO_CMDSRC_ARM);
1200 		aspeed_gpio_change_cmd_source(gpio, bank, 2, GPIO_CMDSRC_ARM);
1201 		aspeed_gpio_change_cmd_source(gpio, bank, 3, GPIO_CMDSRC_ARM);
1202 	}
1203 
1204 	/* Optionally set up an irqchip if there is an IRQ */
1205 	rc = platform_get_irq(pdev, 0);
1206 	if (rc > 0) {
1207 		struct gpio_irq_chip *girq;
1208 
1209 		gpio->irq = rc;
1210 		girq = &gpio->chip.irq;
1211 		girq->chip = &gpio->irqc;
1212 		girq->chip->name = dev_name(&pdev->dev);
1213 		girq->chip->irq_ack = aspeed_gpio_irq_ack;
1214 		girq->chip->irq_mask = aspeed_gpio_irq_mask;
1215 		girq->chip->irq_unmask = aspeed_gpio_irq_unmask;
1216 		girq->chip->irq_set_type = aspeed_gpio_set_type;
1217 		girq->parent_handler = aspeed_gpio_irq_handler;
1218 		girq->num_parents = 1;
1219 		girq->parents = devm_kcalloc(&pdev->dev, 1,
1220 					     sizeof(*girq->parents),
1221 					     GFP_KERNEL);
1222 		if (!girq->parents)
1223 			return -ENOMEM;
1224 		girq->parents[0] = gpio->irq;
1225 		girq->default_type = IRQ_TYPE_NONE;
1226 		girq->handler = handle_bad_irq;
1227 		girq->init_valid_mask = aspeed_init_irq_valid_mask;
1228 	}
1229 
1230 	gpio->offset_timer =
1231 		devm_kzalloc(&pdev->dev, gpio->chip.ngpio, GFP_KERNEL);
1232 	if (!gpio->offset_timer)
1233 		return -ENOMEM;
1234 
1235 	rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
1236 	if (rc < 0)
1237 		return rc;
1238 
1239 	return 0;
1240 }
1241 
1242 static struct platform_driver aspeed_gpio_driver = {
1243 	.driver = {
1244 		.name = KBUILD_MODNAME,
1245 		.of_match_table = aspeed_gpio_of_table,
1246 	},
1247 };
1248 
1249 module_platform_driver_probe(aspeed_gpio_driver, aspeed_gpio_probe);
1250 
1251 MODULE_DESCRIPTION("Aspeed GPIO Driver");
1252 MODULE_LICENSE("GPL");
1253