xref: /linux/drivers/gpio/gpio-eic-sprd.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2018 Spreadtrum Communications Inc.
4  * Copyright (C) 2018 Linaro Ltd.
5  */
6 
7 #include <linux/bitops.h>
8 #include <linux/gpio/driver.h>
9 #include <linux/interrupt.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/notifier.h>
13 #include <linux/of.h>
14 #include <linux/platform_device.h>
15 #include <linux/spinlock.h>
16 
17 /* EIC registers definition */
18 #define SPRD_EIC_DBNC_DATA		0x0
19 #define SPRD_EIC_DBNC_DMSK		0x4
20 #define SPRD_EIC_DBNC_IEV		0x14
21 #define SPRD_EIC_DBNC_IE		0x18
22 #define SPRD_EIC_DBNC_RIS		0x1c
23 #define SPRD_EIC_DBNC_MIS		0x20
24 #define SPRD_EIC_DBNC_IC		0x24
25 #define SPRD_EIC_DBNC_TRIG		0x28
26 #define SPRD_EIC_DBNC_CTRL0		0x40
27 
28 #define SPRD_EIC_LATCH_INTEN		0x0
29 #define SPRD_EIC_LATCH_INTRAW		0x4
30 #define SPRD_EIC_LATCH_INTMSK		0x8
31 #define SPRD_EIC_LATCH_INTCLR		0xc
32 #define SPRD_EIC_LATCH_INTPOL		0x10
33 #define SPRD_EIC_LATCH_INTMODE		0x14
34 
35 #define SPRD_EIC_ASYNC_INTIE		0x0
36 #define SPRD_EIC_ASYNC_INTRAW		0x4
37 #define SPRD_EIC_ASYNC_INTMSK		0x8
38 #define SPRD_EIC_ASYNC_INTCLR		0xc
39 #define SPRD_EIC_ASYNC_INTMODE		0x10
40 #define SPRD_EIC_ASYNC_INTBOTH		0x14
41 #define SPRD_EIC_ASYNC_INTPOL		0x18
42 #define SPRD_EIC_ASYNC_DATA		0x1c
43 
44 #define SPRD_EIC_SYNC_INTIE		0x0
45 #define SPRD_EIC_SYNC_INTRAW		0x4
46 #define SPRD_EIC_SYNC_INTMSK		0x8
47 #define SPRD_EIC_SYNC_INTCLR		0xc
48 #define SPRD_EIC_SYNC_INTMODE		0x10
49 #define SPRD_EIC_SYNC_INTBOTH		0x14
50 #define SPRD_EIC_SYNC_INTPOL		0x18
51 #define SPRD_EIC_SYNC_DATA		0x1c
52 
53 /*
54  * The digital-chip EIC controller can support maximum 3 banks, and each bank
55  * contains 8 EICs.
56  */
57 #define SPRD_EIC_MAX_BANK		3
58 #define SPRD_EIC_PER_BANK_NR		8
59 #define SPRD_EIC_DATA_MASK		GENMASK(7, 0)
60 #define SPRD_EIC_BIT(x)			((x) & (SPRD_EIC_PER_BANK_NR - 1))
61 #define SPRD_EIC_DBNC_MASK		GENMASK(11, 0)
62 
63 /*
64  * The Spreadtrum EIC (external interrupt controller) can be used only in
65  * input mode to generate interrupts if detecting input signals.
66  *
67  * The Spreadtrum digital-chip EIC controller contains 4 sub-modules:
68  * debounce EIC, latch EIC, async EIC and sync EIC,
69  *
70  * The debounce EIC is used to capture the input signals' stable status
71  * (millisecond resolution) and a single-trigger mechanism is introduced
72  * into this sub-module to enhance the input event detection reliability.
73  * The debounce range is from 1ms to 4s with a step size of 1ms.
74  *
75  * The latch EIC is used to latch some special power down signals and
76  * generate interrupts, since the latch EIC does not depend on the APB clock
77  * to capture signals.
78  *
79  * The async EIC uses a 32k clock to capture the short signals (microsecond
80  * resolution) to generate interrupts by level or edge trigger.
81  *
82  * The EIC-sync is similar with GPIO's input function, which is a synchronized
83  * signal input register.
84  */
85 enum sprd_eic_type {
86 	SPRD_EIC_DEBOUNCE,
87 	SPRD_EIC_LATCH,
88 	SPRD_EIC_ASYNC,
89 	SPRD_EIC_SYNC,
90 	SPRD_EIC_MAX,
91 };
92 
93 struct sprd_eic {
94 	struct gpio_chip chip;
95 	struct notifier_block irq_nb;
96 	void __iomem *base[SPRD_EIC_MAX_BANK];
97 	enum sprd_eic_type type;
98 	spinlock_t lock;
99 	int irq;
100 };
101 
102 static ATOMIC_NOTIFIER_HEAD(sprd_eic_irq_notifier);
103 
104 static struct sprd_eic *to_sprd_eic(struct notifier_block *nb)
105 {
106 	return container_of(nb, struct sprd_eic, irq_nb);
107 }
108 
109 struct sprd_eic_variant_data {
110 	enum sprd_eic_type type;
111 };
112 
113 static const char *sprd_eic_label_name[SPRD_EIC_MAX] = {
114 	"eic-debounce", "eic-latch", "eic-async",
115 	"eic-sync",
116 };
117 
118 static const struct sprd_eic_variant_data sc9860_eic_dbnc_data = {
119 	.type = SPRD_EIC_DEBOUNCE,
120 };
121 
122 static const struct sprd_eic_variant_data sc9860_eic_latch_data = {
123 	.type = SPRD_EIC_LATCH,
124 };
125 
126 static const struct sprd_eic_variant_data sc9860_eic_async_data = {
127 	.type = SPRD_EIC_ASYNC,
128 };
129 
130 static const struct sprd_eic_variant_data sc9860_eic_sync_data = {
131 	.type = SPRD_EIC_SYNC,
132 };
133 
134 static inline void __iomem *sprd_eic_offset_base(struct sprd_eic *sprd_eic,
135 						 unsigned int bank)
136 {
137 	if (bank >= SPRD_EIC_MAX_BANK)
138 		return NULL;
139 
140 	return sprd_eic->base[bank];
141 }
142 
143 static void sprd_eic_update(struct gpio_chip *chip, unsigned int offset,
144 			    u16 reg, unsigned int val)
145 {
146 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
147 	void __iomem *base =
148 		sprd_eic_offset_base(sprd_eic, offset / SPRD_EIC_PER_BANK_NR);
149 	unsigned long flags;
150 	u32 tmp;
151 
152 	spin_lock_irqsave(&sprd_eic->lock, flags);
153 	tmp = readl_relaxed(base + reg);
154 
155 	if (val)
156 		tmp |= BIT(SPRD_EIC_BIT(offset));
157 	else
158 		tmp &= ~BIT(SPRD_EIC_BIT(offset));
159 
160 	writel_relaxed(tmp, base + reg);
161 	spin_unlock_irqrestore(&sprd_eic->lock, flags);
162 }
163 
164 static int sprd_eic_read(struct gpio_chip *chip, unsigned int offset, u16 reg)
165 {
166 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
167 	void __iomem *base =
168 		sprd_eic_offset_base(sprd_eic, offset / SPRD_EIC_PER_BANK_NR);
169 
170 	return !!(readl_relaxed(base + reg) & BIT(SPRD_EIC_BIT(offset)));
171 }
172 
173 static int sprd_eic_request(struct gpio_chip *chip, unsigned int offset)
174 {
175 	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_DMSK, 1);
176 	return 0;
177 }
178 
179 static void sprd_eic_free(struct gpio_chip *chip, unsigned int offset)
180 {
181 	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_DMSK, 0);
182 }
183 
184 static int sprd_eic_get(struct gpio_chip *chip, unsigned int offset)
185 {
186 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
187 
188 	switch (sprd_eic->type) {
189 	case SPRD_EIC_DEBOUNCE:
190 		return sprd_eic_read(chip, offset, SPRD_EIC_DBNC_DATA);
191 	case SPRD_EIC_ASYNC:
192 		return sprd_eic_read(chip, offset, SPRD_EIC_ASYNC_DATA);
193 	case SPRD_EIC_SYNC:
194 		return sprd_eic_read(chip, offset, SPRD_EIC_SYNC_DATA);
195 	default:
196 		return -ENOTSUPP;
197 	}
198 }
199 
200 static int sprd_eic_direction_input(struct gpio_chip *chip, unsigned int offset)
201 {
202 	/* EICs are always input, nothing need to do here. */
203 	return 0;
204 }
205 
206 static void sprd_eic_set(struct gpio_chip *chip, unsigned int offset, int value)
207 {
208 	/* EICs are always input, nothing need to do here. */
209 }
210 
211 static int sprd_eic_set_debounce(struct gpio_chip *chip, unsigned int offset,
212 				 unsigned int debounce)
213 {
214 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
215 	void __iomem *base =
216 		sprd_eic_offset_base(sprd_eic, offset / SPRD_EIC_PER_BANK_NR);
217 	u32 reg = SPRD_EIC_DBNC_CTRL0 + SPRD_EIC_BIT(offset) * 0x4;
218 	u32 value = readl_relaxed(base + reg) & ~SPRD_EIC_DBNC_MASK;
219 
220 	value |= (debounce / 1000) & SPRD_EIC_DBNC_MASK;
221 	writel_relaxed(value, base + reg);
222 
223 	return 0;
224 }
225 
226 static int sprd_eic_set_config(struct gpio_chip *chip, unsigned int offset,
227 			       unsigned long config)
228 {
229 	unsigned long param = pinconf_to_config_param(config);
230 	u32 arg = pinconf_to_config_argument(config);
231 
232 	if (param == PIN_CONFIG_INPUT_DEBOUNCE)
233 		return sprd_eic_set_debounce(chip, offset, arg);
234 
235 	return -ENOTSUPP;
236 }
237 
238 static void sprd_eic_irq_mask(struct irq_data *data)
239 {
240 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
241 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
242 	u32 offset = irqd_to_hwirq(data);
243 
244 	switch (sprd_eic->type) {
245 	case SPRD_EIC_DEBOUNCE:
246 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IE, 0);
247 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_TRIG, 0);
248 		break;
249 	case SPRD_EIC_LATCH:
250 		sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTEN, 0);
251 		break;
252 	case SPRD_EIC_ASYNC:
253 		sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTIE, 0);
254 		break;
255 	case SPRD_EIC_SYNC:
256 		sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTIE, 0);
257 		break;
258 	default:
259 		dev_err(chip->parent, "Unsupported EIC type.\n");
260 	}
261 
262 	gpiochip_disable_irq(chip, offset);
263 }
264 
265 static void sprd_eic_irq_unmask(struct irq_data *data)
266 {
267 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
268 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
269 	u32 offset = irqd_to_hwirq(data);
270 
271 	gpiochip_enable_irq(chip, offset);
272 
273 	switch (sprd_eic->type) {
274 	case SPRD_EIC_DEBOUNCE:
275 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IE, 1);
276 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_TRIG, 1);
277 		break;
278 	case SPRD_EIC_LATCH:
279 		sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTEN, 1);
280 		break;
281 	case SPRD_EIC_ASYNC:
282 		sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTIE, 1);
283 		break;
284 	case SPRD_EIC_SYNC:
285 		sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTIE, 1);
286 		break;
287 	default:
288 		dev_err(chip->parent, "Unsupported EIC type.\n");
289 	}
290 }
291 
292 static void sprd_eic_irq_ack(struct irq_data *data)
293 {
294 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
295 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
296 	u32 offset = irqd_to_hwirq(data);
297 
298 	switch (sprd_eic->type) {
299 	case SPRD_EIC_DEBOUNCE:
300 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IC, 1);
301 		break;
302 	case SPRD_EIC_LATCH:
303 		sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTCLR, 1);
304 		break;
305 	case SPRD_EIC_ASYNC:
306 		sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTCLR, 1);
307 		break;
308 	case SPRD_EIC_SYNC:
309 		sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTCLR, 1);
310 		break;
311 	default:
312 		dev_err(chip->parent, "Unsupported EIC type.\n");
313 	}
314 }
315 
316 static int sprd_eic_irq_set_type(struct irq_data *data, unsigned int flow_type)
317 {
318 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
319 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
320 	u32 offset = irqd_to_hwirq(data);
321 	int state;
322 
323 	switch (sprd_eic->type) {
324 	case SPRD_EIC_DEBOUNCE:
325 		switch (flow_type) {
326 		case IRQ_TYPE_LEVEL_HIGH:
327 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 1);
328 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IC, 1);
329 			break;
330 		case IRQ_TYPE_LEVEL_LOW:
331 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0);
332 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IC, 1);
333 			break;
334 		case IRQ_TYPE_EDGE_RISING:
335 		case IRQ_TYPE_EDGE_FALLING:
336 		case IRQ_TYPE_EDGE_BOTH:
337 			state = sprd_eic_get(chip, offset);
338 			if (state) {
339 				sprd_eic_update(chip, offset,
340 						SPRD_EIC_DBNC_IEV, 0);
341 				sprd_eic_update(chip, offset,
342 						SPRD_EIC_DBNC_IC, 1);
343 			} else {
344 				sprd_eic_update(chip, offset,
345 						SPRD_EIC_DBNC_IEV, 1);
346 				sprd_eic_update(chip, offset,
347 						SPRD_EIC_DBNC_IC, 1);
348 			}
349 			break;
350 		default:
351 			return -ENOTSUPP;
352 		}
353 
354 		irq_set_handler_locked(data, handle_level_irq);
355 		break;
356 	case SPRD_EIC_LATCH:
357 		switch (flow_type) {
358 		case IRQ_TYPE_LEVEL_HIGH:
359 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 0);
360 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTCLR, 1);
361 			break;
362 		case IRQ_TYPE_LEVEL_LOW:
363 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1);
364 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTCLR, 1);
365 			break;
366 		case IRQ_TYPE_EDGE_RISING:
367 		case IRQ_TYPE_EDGE_FALLING:
368 		case IRQ_TYPE_EDGE_BOTH:
369 			state = sprd_eic_get(chip, offset);
370 			if (state) {
371 				sprd_eic_update(chip, offset,
372 						SPRD_EIC_LATCH_INTPOL, 0);
373 				sprd_eic_update(chip, offset,
374 						SPRD_EIC_LATCH_INTCLR, 1);
375 			} else {
376 				sprd_eic_update(chip, offset,
377 						SPRD_EIC_LATCH_INTPOL, 1);
378 				sprd_eic_update(chip, offset,
379 						SPRD_EIC_LATCH_INTCLR, 1);
380 			}
381 			break;
382 		default:
383 			return -ENOTSUPP;
384 		}
385 
386 		irq_set_handler_locked(data, handle_level_irq);
387 		break;
388 	case SPRD_EIC_ASYNC:
389 		switch (flow_type) {
390 		case IRQ_TYPE_EDGE_RISING:
391 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
392 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 0);
393 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 1);
394 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTCLR, 1);
395 			irq_set_handler_locked(data, handle_edge_irq);
396 			break;
397 		case IRQ_TYPE_EDGE_FALLING:
398 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
399 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 0);
400 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 0);
401 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTCLR, 1);
402 			irq_set_handler_locked(data, handle_edge_irq);
403 			break;
404 		case IRQ_TYPE_EDGE_BOTH:
405 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 0);
406 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 1);
407 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTCLR, 1);
408 			irq_set_handler_locked(data, handle_edge_irq);
409 			break;
410 		case IRQ_TYPE_LEVEL_HIGH:
411 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
412 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 1);
413 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 1);
414 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTCLR, 1);
415 			irq_set_handler_locked(data, handle_level_irq);
416 			break;
417 		case IRQ_TYPE_LEVEL_LOW:
418 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
419 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 1);
420 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 0);
421 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTCLR, 1);
422 			irq_set_handler_locked(data, handle_level_irq);
423 			break;
424 		default:
425 			return -ENOTSUPP;
426 		}
427 		break;
428 	case SPRD_EIC_SYNC:
429 		switch (flow_type) {
430 		case IRQ_TYPE_EDGE_RISING:
431 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
432 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
433 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 1);
434 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTCLR, 1);
435 			irq_set_handler_locked(data, handle_edge_irq);
436 			break;
437 		case IRQ_TYPE_EDGE_FALLING:
438 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
439 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
440 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 0);
441 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTCLR, 1);
442 			irq_set_handler_locked(data, handle_edge_irq);
443 			break;
444 		case IRQ_TYPE_EDGE_BOTH:
445 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
446 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 1);
447 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTCLR, 1);
448 			irq_set_handler_locked(data, handle_edge_irq);
449 			break;
450 		case IRQ_TYPE_LEVEL_HIGH:
451 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
452 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 1);
453 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 1);
454 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTCLR, 1);
455 			irq_set_handler_locked(data, handle_level_irq);
456 			break;
457 		case IRQ_TYPE_LEVEL_LOW:
458 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
459 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 1);
460 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 0);
461 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTCLR, 1);
462 			irq_set_handler_locked(data, handle_level_irq);
463 			break;
464 		default:
465 			return -ENOTSUPP;
466 		}
467 		break;
468 	default:
469 		dev_err(chip->parent, "Unsupported EIC type.\n");
470 		return -ENOTSUPP;
471 	}
472 
473 	return 0;
474 }
475 
476 static void sprd_eic_toggle_trigger(struct gpio_chip *chip, unsigned int irq,
477 				    unsigned int offset)
478 {
479 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
480 	struct irq_data *data = irq_get_irq_data(irq);
481 	u32 trigger = irqd_get_trigger_type(data);
482 	int state, post_state;
483 
484 	/*
485 	 * The debounce EIC and latch EIC can only support level trigger, so we
486 	 * can toggle the level trigger to emulate the edge trigger.
487 	 */
488 	if ((sprd_eic->type != SPRD_EIC_DEBOUNCE &&
489 	     sprd_eic->type != SPRD_EIC_LATCH) ||
490 	    !(trigger & IRQ_TYPE_EDGE_BOTH))
491 		return;
492 
493 	sprd_eic_irq_mask(data);
494 	state = sprd_eic_get(chip, offset);
495 
496 retry:
497 	switch (sprd_eic->type) {
498 	case SPRD_EIC_DEBOUNCE:
499 		if (state)
500 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0);
501 		else
502 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 1);
503 		break;
504 	case SPRD_EIC_LATCH:
505 		if (state)
506 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 0);
507 		else
508 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1);
509 		break;
510 	default:
511 		sprd_eic_irq_unmask(data);
512 		return;
513 	}
514 
515 	post_state = sprd_eic_get(chip, offset);
516 	if (state != post_state) {
517 		dev_warn(chip->parent, "EIC level was changed.\n");
518 		state = post_state;
519 		goto retry;
520 	}
521 
522 	sprd_eic_irq_unmask(data);
523 }
524 
525 static void sprd_eic_handle_one_type(struct gpio_chip *chip)
526 {
527 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
528 	u32 bank, n, girq;
529 
530 	for (bank = 0; bank * SPRD_EIC_PER_BANK_NR < chip->ngpio; bank++) {
531 		void __iomem *base = sprd_eic_offset_base(sprd_eic, bank);
532 		unsigned long reg;
533 
534 		switch (sprd_eic->type) {
535 		case SPRD_EIC_DEBOUNCE:
536 			reg = readl_relaxed(base + SPRD_EIC_DBNC_MIS) &
537 				SPRD_EIC_DATA_MASK;
538 			break;
539 		case SPRD_EIC_LATCH:
540 			reg = readl_relaxed(base + SPRD_EIC_LATCH_INTMSK) &
541 				SPRD_EIC_DATA_MASK;
542 			break;
543 		case SPRD_EIC_ASYNC:
544 			reg = readl_relaxed(base + SPRD_EIC_ASYNC_INTMSK) &
545 				SPRD_EIC_DATA_MASK;
546 			break;
547 		case SPRD_EIC_SYNC:
548 			reg = readl_relaxed(base + SPRD_EIC_SYNC_INTMSK) &
549 				SPRD_EIC_DATA_MASK;
550 			break;
551 		default:
552 			dev_err(chip->parent, "Unsupported EIC type.\n");
553 			return;
554 		}
555 
556 		for_each_set_bit(n, &reg, SPRD_EIC_PER_BANK_NR) {
557 			u32 offset = bank * SPRD_EIC_PER_BANK_NR + n;
558 
559 			girq = irq_find_mapping(chip->irq.domain, offset);
560 
561 			generic_handle_irq(girq);
562 			sprd_eic_toggle_trigger(chip, girq, offset);
563 		}
564 	}
565 }
566 
567 static void sprd_eic_irq_handler(struct irq_desc *desc)
568 {
569 	struct irq_chip *ic = irq_desc_get_chip(desc);
570 
571 	chained_irq_enter(ic, desc);
572 
573 	/*
574 	 * Since the digital-chip EIC 4 sub-modules (debounce, latch, async
575 	 * and sync) share one same interrupt line, we should notify all of
576 	 * them to let them check if there are EIC interrupts were triggered.
577 	 */
578 	atomic_notifier_call_chain(&sprd_eic_irq_notifier, 0, NULL);
579 
580 	chained_irq_exit(ic, desc);
581 }
582 
583 static int sprd_eic_irq_notify(struct notifier_block *nb, unsigned long action,
584 			       void *data)
585 {
586 	struct sprd_eic *sprd_eic = to_sprd_eic(nb);
587 
588 	sprd_eic_handle_one_type(&sprd_eic->chip);
589 
590 	return NOTIFY_OK;
591 }
592 
593 static const struct irq_chip sprd_eic_irq = {
594 	.name		= "sprd-eic",
595 	.irq_ack	= sprd_eic_irq_ack,
596 	.irq_mask	= sprd_eic_irq_mask,
597 	.irq_unmask	= sprd_eic_irq_unmask,
598 	.irq_set_type	= sprd_eic_irq_set_type,
599 	.flags		= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_IMMUTABLE,
600 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
601 };
602 
603 static void sprd_eic_unregister_notifier(void *data)
604 {
605 	struct notifier_block *nb = data;
606 
607 	atomic_notifier_chain_unregister(&sprd_eic_irq_notifier, nb);
608 }
609 
610 static int sprd_eic_probe(struct platform_device *pdev)
611 {
612 	const struct sprd_eic_variant_data *pdata;
613 	struct device *dev = &pdev->dev;
614 	struct gpio_irq_chip *irq;
615 	struct sprd_eic *sprd_eic;
616 	struct resource *res;
617 	u16 num_banks = 0;
618 	int ret, i;
619 
620 	pdata = of_device_get_match_data(dev);
621 	if (!pdata) {
622 		dev_err(dev, "No matching driver data found.\n");
623 		return -EINVAL;
624 	}
625 
626 	sprd_eic = devm_kzalloc(dev, sizeof(*sprd_eic), GFP_KERNEL);
627 	if (!sprd_eic)
628 		return -ENOMEM;
629 
630 	spin_lock_init(&sprd_eic->lock);
631 	sprd_eic->type = pdata->type;
632 
633 	sprd_eic->irq = platform_get_irq(pdev, 0);
634 	if (sprd_eic->irq < 0)
635 		return sprd_eic->irq;
636 
637 	for (i = 0; i < SPRD_EIC_MAX_BANK; i++) {
638 		/*
639 		 * We can have maximum 3 banks EICs, and each EIC has
640 		 * its own base address. But some platform maybe only
641 		 * have one bank EIC, thus base[1] and base[2] can be
642 		 * optional.
643 		 */
644 		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
645 		if (!res)
646 			break;
647 
648 		sprd_eic->base[i] = devm_ioremap_resource(dev, res);
649 		if (IS_ERR(sprd_eic->base[i]))
650 			return PTR_ERR(sprd_eic->base[i]);
651 
652 		num_banks++;
653 	}
654 
655 	sprd_eic->chip.label = sprd_eic_label_name[sprd_eic->type];
656 	sprd_eic->chip.ngpio = num_banks * SPRD_EIC_PER_BANK_NR;
657 	sprd_eic->chip.base = -1;
658 	sprd_eic->chip.parent = dev;
659 	sprd_eic->chip.direction_input = sprd_eic_direction_input;
660 	switch (sprd_eic->type) {
661 	case SPRD_EIC_DEBOUNCE:
662 		sprd_eic->chip.request = sprd_eic_request;
663 		sprd_eic->chip.free = sprd_eic_free;
664 		sprd_eic->chip.set_config = sprd_eic_set_config;
665 		sprd_eic->chip.set = sprd_eic_set;
666 		fallthrough;
667 	case SPRD_EIC_ASYNC:
668 	case SPRD_EIC_SYNC:
669 		sprd_eic->chip.get = sprd_eic_get;
670 		break;
671 	case SPRD_EIC_LATCH:
672 	default:
673 		break;
674 	}
675 
676 	irq = &sprd_eic->chip.irq;
677 	gpio_irq_chip_set_chip(irq, &sprd_eic_irq);
678 	irq->handler = handle_bad_irq;
679 	irq->default_type = IRQ_TYPE_NONE;
680 	irq->parent_handler = sprd_eic_irq_handler;
681 	irq->parent_handler_data = sprd_eic;
682 	irq->num_parents = 1;
683 	irq->parents = &sprd_eic->irq;
684 
685 	ret = devm_gpiochip_add_data(dev, &sprd_eic->chip, sprd_eic);
686 	if (ret < 0) {
687 		dev_err(dev, "Could not register gpiochip %d.\n", ret);
688 		return ret;
689 	}
690 
691 	sprd_eic->irq_nb.notifier_call = sprd_eic_irq_notify;
692 	ret = atomic_notifier_chain_register(&sprd_eic_irq_notifier,
693 					     &sprd_eic->irq_nb);
694 	if (ret)
695 		return dev_err_probe(dev, ret,
696 				     "Failed to register with the interrupt notifier");
697 
698 	return devm_add_action_or_reset(dev, sprd_eic_unregister_notifier,
699 					&sprd_eic->irq_nb);
700 }
701 
702 static const struct of_device_id sprd_eic_of_match[] = {
703 	{
704 		.compatible = "sprd,sc9860-eic-debounce",
705 		.data = &sc9860_eic_dbnc_data,
706 	},
707 	{
708 		.compatible = "sprd,sc9860-eic-latch",
709 		.data = &sc9860_eic_latch_data,
710 	},
711 	{
712 		.compatible = "sprd,sc9860-eic-async",
713 		.data = &sc9860_eic_async_data,
714 	},
715 	{
716 		.compatible = "sprd,sc9860-eic-sync",
717 		.data = &sc9860_eic_sync_data,
718 	},
719 	{
720 		/* end of list */
721 	}
722 };
723 MODULE_DEVICE_TABLE(of, sprd_eic_of_match);
724 
725 static struct platform_driver sprd_eic_driver = {
726 	.probe = sprd_eic_probe,
727 	.driver = {
728 		.name = "sprd-eic",
729 		.of_match_table	= sprd_eic_of_match,
730 	},
731 };
732 
733 module_platform_driver(sprd_eic_driver);
734 
735 MODULE_DESCRIPTION("Spreadtrum EIC driver");
736 MODULE_LICENSE("GPL v2");
737