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
31struct aspeed_bank_props {
32	unsigned int bank;
33	u32 input;
34	u32 output;
35};
36
37struct 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 */
53struct aspeed_gpio {
54	struct gpio_chip chip;
55	struct irq_chip irqc;
56	raw_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
69struct 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
92static const int debounce_timers[4] = { 0x00, 0x50, 0x54, 0x58 };
93
94static const struct aspeed_gpio_copro_ops *copro_ops;
95static void *copro_data;
96
97static 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
172enum 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 */
208static 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
251static 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
259static inline bool is_bank_props_sentinel(const struct aspeed_bank_props *props)
260{
261	return !(props->input || props->output);
262}
263
264static 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
278static 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
288static 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
298static 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
305static 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
337static 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
361static 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
381static 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
389static 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
409static 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	raw_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	raw_spin_unlock_irqrestore(&gpio->lock, flags);
424}
425
426static 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	raw_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	raw_spin_unlock_irqrestore(&gpio->lock, flags);
449
450	return 0;
451}
452
453static 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	raw_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	raw_spin_unlock_irqrestore(&gpio->lock, flags);
478
479	return 0;
480}
481
482static 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	raw_spin_lock_irqsave(&gpio->lock, flags);
496
497	val = ioread32(bank_reg(gpio, bank, reg_dir)) & GPIO_BIT(offset);
498
499	raw_spin_unlock_irqrestore(&gpio->lock, flags);
500
501	return val ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
502}
503
504static 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
526static 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	raw_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	raw_spin_unlock_irqrestore(&gpio->lock, flags);
550}
551
552static 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	raw_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	raw_spin_unlock_irqrestore(&gpio->lock, flags);
581}
582
583static void aspeed_gpio_irq_mask(struct irq_data *d)
584{
585	aspeed_gpio_irq_set_mask(d, false);
586}
587
588static void aspeed_gpio_irq_unmask(struct irq_data *d)
589{
590	aspeed_gpio_irq_set_mask(d, true);
591}
592
593static 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	raw_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	raw_spin_unlock_irqrestore(&gpio->lock, flags);
653
654	irq_set_handler_locked(d, handler);
655
656	return 0;
657}
658
659static 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
686static 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
711static 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	raw_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	raw_spin_unlock_irqrestore(&gpio->lock, flags);
737
738	return 0;
739}
740
741static 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
749static void aspeed_gpio_free(struct gpio_chip *chip, unsigned int offset)
750{
751	pinctrl_gpio_free(chip->base + offset);
752}
753
754static 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 */
778static 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 */
797static 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 */
816static 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 */
823static 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
843static 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	raw_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
921out:
922	raw_spin_unlock_irqrestore(&gpio->lock, flags);
923
924	return rc;
925}
926
927static 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	raw_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	raw_spin_unlock_irqrestore(&gpio->lock, flags);
940
941	return rc;
942}
943
944static 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
958static 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(chip->base + 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 */
986int 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}
993EXPORT_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 */
1004int 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	raw_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	raw_spin_unlock_irqrestore(&gpio->lock, flags);
1043	return rc;
1044}
1045EXPORT_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 */
1051int 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	raw_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	raw_spin_unlock_irqrestore(&gpio->lock, flags);
1081	return rc;
1082}
1083EXPORT_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
1092static 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
1099static 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
1103static 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
1111static 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
1115static const struct aspeed_bank_props ast2600_bank_props[] = {
1116	/*     input	  output   */
1117	{4, 0xffffffff,  0x00ffffff}, /* Q/R/S/T */
1118	{5, 0xffffffff,  0xffffff00}, /* U/V/W/X */
1119	{6, 0x0000ffff,  0x0000ffff}, /* Y/Z */
1120	{ },
1121};
1122
1123static 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
1131static 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};
1137MODULE_DEVICE_TABLE(of, aspeed_gpio_of_table);
1138
1139static 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	raw_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
1244static struct platform_driver aspeed_gpio_driver = {
1245	.driver = {
1246		.name = KBUILD_MODNAME,
1247		.of_match_table = aspeed_gpio_of_table,
1248	},
1249};
1250
1251module_platform_driver_probe(aspeed_gpio_driver, aspeed_gpio_probe);
1252
1253MODULE_DESCRIPTION("Aspeed GPIO Driver");
1254MODULE_LICENSE("GPL");
1255