xref: /openbmc/linux/drivers/gpio/gpio-eic-sprd.c (revision 9a29f5fc)
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/of_device.h>
13 #include <linux/platform_device.h>
14 #include <linux/spinlock.h>
15 
16 /* EIC registers definition */
17 #define SPRD_EIC_DBNC_DATA		0x0
18 #define SPRD_EIC_DBNC_DMSK		0x4
19 #define SPRD_EIC_DBNC_IEV		0x14
20 #define SPRD_EIC_DBNC_IE		0x18
21 #define SPRD_EIC_DBNC_RIS		0x1c
22 #define SPRD_EIC_DBNC_MIS		0x20
23 #define SPRD_EIC_DBNC_IC		0x24
24 #define SPRD_EIC_DBNC_TRIG		0x28
25 #define SPRD_EIC_DBNC_CTRL0		0x40
26 
27 #define SPRD_EIC_LATCH_INTEN		0x0
28 #define SPRD_EIC_LATCH_INTRAW		0x4
29 #define SPRD_EIC_LATCH_INTMSK		0x8
30 #define SPRD_EIC_LATCH_INTCLR		0xc
31 #define SPRD_EIC_LATCH_INTPOL		0x10
32 #define SPRD_EIC_LATCH_INTMODE		0x14
33 
34 #define SPRD_EIC_ASYNC_INTIE		0x0
35 #define SPRD_EIC_ASYNC_INTRAW		0x4
36 #define SPRD_EIC_ASYNC_INTMSK		0x8
37 #define SPRD_EIC_ASYNC_INTCLR		0xc
38 #define SPRD_EIC_ASYNC_INTMODE		0x10
39 #define SPRD_EIC_ASYNC_INTBOTH		0x14
40 #define SPRD_EIC_ASYNC_INTPOL		0x18
41 #define SPRD_EIC_ASYNC_DATA		0x1c
42 
43 #define SPRD_EIC_SYNC_INTIE		0x0
44 #define SPRD_EIC_SYNC_INTRAW		0x4
45 #define SPRD_EIC_SYNC_INTMSK		0x8
46 #define SPRD_EIC_SYNC_INTCLR		0xc
47 #define SPRD_EIC_SYNC_INTMODE		0x10
48 #define SPRD_EIC_SYNC_INTBOTH		0x14
49 #define SPRD_EIC_SYNC_INTPOL		0x18
50 #define SPRD_EIC_SYNC_DATA		0x1c
51 
52 /*
53  * The digital-chip EIC controller can support maximum 3 banks, and each bank
54  * contains 8 EICs.
55  */
56 #define SPRD_EIC_MAX_BANK		3
57 #define SPRD_EIC_PER_BANK_NR		8
58 #define SPRD_EIC_DATA_MASK		GENMASK(7, 0)
59 #define SPRD_EIC_BIT(x)			((x) & (SPRD_EIC_PER_BANK_NR - 1))
60 #define SPRD_EIC_DBNC_MASK		GENMASK(11, 0)
61 
62 /*
63  * The Spreadtrum EIC (external interrupt controller) can be used only in
64  * input mode to generate interrupts if detecting input signals.
65  *
66  * The Spreadtrum digital-chip EIC controller contains 4 sub-modules:
67  * debounce EIC, latch EIC, async EIC and sync EIC,
68  *
69  * The debounce EIC is used to capture the input signals' stable status
70  * (millisecond resolution) and a single-trigger mechanism is introduced
71  * into this sub-module to enhance the input event detection reliability.
72  * The debounce range is from 1ms to 4s with a step size of 1ms.
73  *
74  * The latch EIC is used to latch some special power down signals and
75  * generate interrupts, since the latch EIC does not depend on the APB clock
76  * to capture signals.
77  *
78  * The async EIC uses a 32k clock to capture the short signals (microsecond
79  * resolution) to generate interrupts by level or edge trigger.
80  *
81  * The EIC-sync is similar with GPIO's input function, which is a synchronized
82  * signal input register.
83  */
84 enum sprd_eic_type {
85 	SPRD_EIC_DEBOUNCE,
86 	SPRD_EIC_LATCH,
87 	SPRD_EIC_ASYNC,
88 	SPRD_EIC_SYNC,
89 	SPRD_EIC_MAX,
90 };
91 
92 struct sprd_eic {
93 	struct gpio_chip chip;
94 	struct irq_chip intc;
95 	void __iomem *base[SPRD_EIC_MAX_BANK];
96 	enum sprd_eic_type type;
97 	spinlock_t lock;
98 	int irq;
99 };
100 
101 struct sprd_eic_variant_data {
102 	enum sprd_eic_type type;
103 	u32 num_eics;
104 };
105 
106 static const char *sprd_eic_label_name[SPRD_EIC_MAX] = {
107 	"eic-debounce", "eic-latch", "eic-async",
108 	"eic-sync",
109 };
110 
111 static const struct sprd_eic_variant_data sc9860_eic_dbnc_data = {
112 	.type = SPRD_EIC_DEBOUNCE,
113 	.num_eics = 8,
114 };
115 
116 static const struct sprd_eic_variant_data sc9860_eic_latch_data = {
117 	.type = SPRD_EIC_LATCH,
118 	.num_eics = 8,
119 };
120 
121 static const struct sprd_eic_variant_data sc9860_eic_async_data = {
122 	.type = SPRD_EIC_ASYNC,
123 	.num_eics = 8,
124 };
125 
126 static const struct sprd_eic_variant_data sc9860_eic_sync_data = {
127 	.type = SPRD_EIC_SYNC,
128 	.num_eics = 8,
129 };
130 
131 static inline void __iomem *sprd_eic_offset_base(struct sprd_eic *sprd_eic,
132 						 unsigned int bank)
133 {
134 	if (bank >= SPRD_EIC_MAX_BANK)
135 		return NULL;
136 
137 	return sprd_eic->base[bank];
138 }
139 
140 static void sprd_eic_update(struct gpio_chip *chip, unsigned int offset,
141 			    u16 reg, unsigned int val)
142 {
143 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
144 	void __iomem *base =
145 		sprd_eic_offset_base(sprd_eic, offset / SPRD_EIC_PER_BANK_NR);
146 	unsigned long flags;
147 	u32 tmp;
148 
149 	spin_lock_irqsave(&sprd_eic->lock, flags);
150 	tmp = readl_relaxed(base + reg);
151 
152 	if (val)
153 		tmp |= BIT(SPRD_EIC_BIT(offset));
154 	else
155 		tmp &= ~BIT(SPRD_EIC_BIT(offset));
156 
157 	writel_relaxed(tmp, base + reg);
158 	spin_unlock_irqrestore(&sprd_eic->lock, flags);
159 }
160 
161 static int sprd_eic_read(struct gpio_chip *chip, unsigned int offset, u16 reg)
162 {
163 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
164 	void __iomem *base =
165 		sprd_eic_offset_base(sprd_eic, offset / SPRD_EIC_PER_BANK_NR);
166 
167 	return !!(readl_relaxed(base + reg) & BIT(SPRD_EIC_BIT(offset)));
168 }
169 
170 static int sprd_eic_request(struct gpio_chip *chip, unsigned int offset)
171 {
172 	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_DMSK, 1);
173 	return 0;
174 }
175 
176 static void sprd_eic_free(struct gpio_chip *chip, unsigned int offset)
177 {
178 	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_DMSK, 0);
179 }
180 
181 static int sprd_eic_get(struct gpio_chip *chip, unsigned int offset)
182 {
183 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
184 
185 	switch (sprd_eic->type) {
186 	case SPRD_EIC_DEBOUNCE:
187 		return sprd_eic_read(chip, offset, SPRD_EIC_DBNC_DATA);
188 	case SPRD_EIC_ASYNC:
189 		return sprd_eic_read(chip, offset, SPRD_EIC_ASYNC_DATA);
190 	case SPRD_EIC_SYNC:
191 		return sprd_eic_read(chip, offset, SPRD_EIC_SYNC_DATA);
192 	default:
193 		return -ENOTSUPP;
194 	}
195 }
196 
197 static int sprd_eic_direction_input(struct gpio_chip *chip, unsigned int offset)
198 {
199 	/* EICs are always input, nothing need to do here. */
200 	return 0;
201 }
202 
203 static void sprd_eic_set(struct gpio_chip *chip, unsigned int offset, int value)
204 {
205 	/* EICs are always input, nothing need to do here. */
206 }
207 
208 static int sprd_eic_set_debounce(struct gpio_chip *chip, unsigned int offset,
209 				 unsigned int debounce)
210 {
211 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
212 	void __iomem *base =
213 		sprd_eic_offset_base(sprd_eic, offset / SPRD_EIC_PER_BANK_NR);
214 	u32 reg = SPRD_EIC_DBNC_CTRL0 + SPRD_EIC_BIT(offset) * 0x4;
215 	u32 value = readl_relaxed(base + reg) & ~SPRD_EIC_DBNC_MASK;
216 
217 	value |= (debounce / 1000) & SPRD_EIC_DBNC_MASK;
218 	writel_relaxed(value, base + reg);
219 
220 	return 0;
221 }
222 
223 static int sprd_eic_set_config(struct gpio_chip *chip, unsigned int offset,
224 			       unsigned long config)
225 {
226 	unsigned long param = pinconf_to_config_param(config);
227 	u32 arg = pinconf_to_config_argument(config);
228 
229 	if (param == PIN_CONFIG_INPUT_DEBOUNCE)
230 		return sprd_eic_set_debounce(chip, offset, arg);
231 
232 	return -ENOTSUPP;
233 }
234 
235 static void sprd_eic_irq_mask(struct irq_data *data)
236 {
237 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
238 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
239 	u32 offset = irqd_to_hwirq(data);
240 
241 	switch (sprd_eic->type) {
242 	case SPRD_EIC_DEBOUNCE:
243 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IE, 0);
244 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_TRIG, 0);
245 		break;
246 	case SPRD_EIC_LATCH:
247 		sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTEN, 0);
248 		break;
249 	case SPRD_EIC_ASYNC:
250 		sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTIE, 0);
251 		break;
252 	case SPRD_EIC_SYNC:
253 		sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTIE, 0);
254 		break;
255 	default:
256 		dev_err(chip->parent, "Unsupported EIC type.\n");
257 	}
258 }
259 
260 static void sprd_eic_irq_unmask(struct irq_data *data)
261 {
262 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
263 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
264 	u32 offset = irqd_to_hwirq(data);
265 
266 	switch (sprd_eic->type) {
267 	case SPRD_EIC_DEBOUNCE:
268 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IE, 1);
269 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_TRIG, 1);
270 		break;
271 	case SPRD_EIC_LATCH:
272 		sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTEN, 1);
273 		break;
274 	case SPRD_EIC_ASYNC:
275 		sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTIE, 1);
276 		break;
277 	case SPRD_EIC_SYNC:
278 		sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTIE, 1);
279 		break;
280 	default:
281 		dev_err(chip->parent, "Unsupported EIC type.\n");
282 	}
283 }
284 
285 static void sprd_eic_irq_ack(struct irq_data *data)
286 {
287 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
288 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
289 	u32 offset = irqd_to_hwirq(data);
290 
291 	switch (sprd_eic->type) {
292 	case SPRD_EIC_DEBOUNCE:
293 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IC, 1);
294 		break;
295 	case SPRD_EIC_LATCH:
296 		sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTCLR, 1);
297 		break;
298 	case SPRD_EIC_ASYNC:
299 		sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTCLR, 1);
300 		break;
301 	case SPRD_EIC_SYNC:
302 		sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTCLR, 1);
303 		break;
304 	default:
305 		dev_err(chip->parent, "Unsupported EIC type.\n");
306 	}
307 }
308 
309 static int sprd_eic_irq_set_type(struct irq_data *data, unsigned int flow_type)
310 {
311 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
312 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
313 	u32 offset = irqd_to_hwirq(data);
314 	int state;
315 
316 	switch (sprd_eic->type) {
317 	case SPRD_EIC_DEBOUNCE:
318 		switch (flow_type) {
319 		case IRQ_TYPE_LEVEL_HIGH:
320 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 1);
321 			break;
322 		case IRQ_TYPE_LEVEL_LOW:
323 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0);
324 			break;
325 		case IRQ_TYPE_EDGE_RISING:
326 		case IRQ_TYPE_EDGE_FALLING:
327 		case IRQ_TYPE_EDGE_BOTH:
328 			state = sprd_eic_get(chip, offset);
329 			if (state)
330 				sprd_eic_update(chip, offset,
331 						SPRD_EIC_DBNC_IEV, 0);
332 			else
333 				sprd_eic_update(chip, offset,
334 						SPRD_EIC_DBNC_IEV, 1);
335 			break;
336 		default:
337 			return -ENOTSUPP;
338 		}
339 
340 		irq_set_handler_locked(data, handle_level_irq);
341 		break;
342 	case SPRD_EIC_LATCH:
343 		switch (flow_type) {
344 		case IRQ_TYPE_LEVEL_HIGH:
345 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 0);
346 			break;
347 		case IRQ_TYPE_LEVEL_LOW:
348 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1);
349 			break;
350 		case IRQ_TYPE_EDGE_RISING:
351 		case IRQ_TYPE_EDGE_FALLING:
352 		case IRQ_TYPE_EDGE_BOTH:
353 			state = sprd_eic_get(chip, offset);
354 			if (state)
355 				sprd_eic_update(chip, offset,
356 						SPRD_EIC_LATCH_INTPOL, 0);
357 			else
358 				sprd_eic_update(chip, offset,
359 						SPRD_EIC_LATCH_INTPOL, 1);
360 			break;
361 		default:
362 			return -ENOTSUPP;
363 		}
364 
365 		irq_set_handler_locked(data, handle_level_irq);
366 		break;
367 	case SPRD_EIC_ASYNC:
368 		switch (flow_type) {
369 		case IRQ_TYPE_EDGE_RISING:
370 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
371 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 0);
372 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 1);
373 			irq_set_handler_locked(data, handle_edge_irq);
374 			break;
375 		case IRQ_TYPE_EDGE_FALLING:
376 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
377 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 0);
378 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 0);
379 			irq_set_handler_locked(data, handle_edge_irq);
380 			break;
381 		case IRQ_TYPE_EDGE_BOTH:
382 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 0);
383 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 1);
384 			irq_set_handler_locked(data, handle_edge_irq);
385 			break;
386 		case IRQ_TYPE_LEVEL_HIGH:
387 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
388 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 1);
389 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 1);
390 			irq_set_handler_locked(data, handle_level_irq);
391 			break;
392 		case IRQ_TYPE_LEVEL_LOW:
393 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
394 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 1);
395 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 0);
396 			irq_set_handler_locked(data, handle_level_irq);
397 			break;
398 		default:
399 			return -ENOTSUPP;
400 		}
401 		break;
402 	case SPRD_EIC_SYNC:
403 		switch (flow_type) {
404 		case IRQ_TYPE_EDGE_RISING:
405 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
406 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
407 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 1);
408 			irq_set_handler_locked(data, handle_edge_irq);
409 			break;
410 		case IRQ_TYPE_EDGE_FALLING:
411 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
412 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
413 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 0);
414 			irq_set_handler_locked(data, handle_edge_irq);
415 			break;
416 		case IRQ_TYPE_EDGE_BOTH:
417 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
418 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 1);
419 			irq_set_handler_locked(data, handle_edge_irq);
420 			break;
421 		case IRQ_TYPE_LEVEL_HIGH:
422 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
423 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 1);
424 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 1);
425 			irq_set_handler_locked(data, handle_level_irq);
426 			break;
427 		case IRQ_TYPE_LEVEL_LOW:
428 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
429 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 1);
430 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 0);
431 			irq_set_handler_locked(data, handle_level_irq);
432 			break;
433 		default:
434 			return -ENOTSUPP;
435 		}
436 		break;
437 	default:
438 		dev_err(chip->parent, "Unsupported EIC type.\n");
439 		return -ENOTSUPP;
440 	}
441 
442 	return 0;
443 }
444 
445 static void sprd_eic_toggle_trigger(struct gpio_chip *chip, unsigned int irq,
446 				    unsigned int offset)
447 {
448 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
449 	struct irq_data *data = irq_get_irq_data(irq);
450 	u32 trigger = irqd_get_trigger_type(data);
451 	int state, post_state;
452 
453 	/*
454 	 * The debounce EIC and latch EIC can only support level trigger, so we
455 	 * can toggle the level trigger to emulate the edge trigger.
456 	 */
457 	if ((sprd_eic->type != SPRD_EIC_DEBOUNCE &&
458 	     sprd_eic->type != SPRD_EIC_LATCH) ||
459 	    !(trigger & IRQ_TYPE_EDGE_BOTH))
460 		return;
461 
462 	sprd_eic_irq_mask(data);
463 	state = sprd_eic_get(chip, offset);
464 
465 retry:
466 	switch (sprd_eic->type) {
467 	case SPRD_EIC_DEBOUNCE:
468 		if (state)
469 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0);
470 		else
471 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 1);
472 		break;
473 	case SPRD_EIC_LATCH:
474 		if (state)
475 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 0);
476 		else
477 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1);
478 		break;
479 	default:
480 		sprd_eic_irq_unmask(data);
481 		return;
482 	}
483 
484 	post_state = sprd_eic_get(chip, offset);
485 	if (state != post_state) {
486 		dev_warn(chip->parent, "EIC level was changed.\n");
487 		state = post_state;
488 		goto retry;
489 	}
490 
491 	sprd_eic_irq_unmask(data);
492 }
493 
494 static int sprd_eic_match_chip_by_type(struct gpio_chip *chip, void *data)
495 {
496 	enum sprd_eic_type type = *(enum sprd_eic_type *)data;
497 
498 	return !strcmp(chip->label, sprd_eic_label_name[type]);
499 }
500 
501 static void sprd_eic_handle_one_type(struct gpio_chip *chip)
502 {
503 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
504 	u32 bank, n, girq;
505 
506 	for (bank = 0; bank * SPRD_EIC_PER_BANK_NR < chip->ngpio; bank++) {
507 		void __iomem *base = sprd_eic_offset_base(sprd_eic, bank);
508 		unsigned long reg;
509 
510 		switch (sprd_eic->type) {
511 		case SPRD_EIC_DEBOUNCE:
512 			reg = readl_relaxed(base + SPRD_EIC_DBNC_MIS) &
513 				SPRD_EIC_DATA_MASK;
514 			break;
515 		case SPRD_EIC_LATCH:
516 			reg = readl_relaxed(base + SPRD_EIC_LATCH_INTMSK) &
517 				SPRD_EIC_DATA_MASK;
518 			break;
519 		case SPRD_EIC_ASYNC:
520 			reg = readl_relaxed(base + SPRD_EIC_ASYNC_INTMSK) &
521 				SPRD_EIC_DATA_MASK;
522 			break;
523 		case SPRD_EIC_SYNC:
524 			reg = readl_relaxed(base + SPRD_EIC_SYNC_INTMSK) &
525 				SPRD_EIC_DATA_MASK;
526 			break;
527 		default:
528 			dev_err(chip->parent, "Unsupported EIC type.\n");
529 			return;
530 		}
531 
532 		for_each_set_bit(n, &reg, SPRD_EIC_PER_BANK_NR) {
533 			u32 offset = bank * SPRD_EIC_PER_BANK_NR + n;
534 
535 			girq = irq_find_mapping(chip->irq.domain, offset);
536 
537 			generic_handle_irq(girq);
538 			sprd_eic_toggle_trigger(chip, girq, offset);
539 		}
540 	}
541 }
542 
543 static void sprd_eic_irq_handler(struct irq_desc *desc)
544 {
545 	struct irq_chip *ic = irq_desc_get_chip(desc);
546 	struct gpio_chip *chip;
547 	enum sprd_eic_type type;
548 
549 	chained_irq_enter(ic, desc);
550 
551 	/*
552 	 * Since the digital-chip EIC 4 sub-modules (debounce, latch, async
553 	 * and sync) share one same interrupt line, we should iterate each
554 	 * EIC module to check if there are EIC interrupts were triggered.
555 	 */
556 	for (type = SPRD_EIC_DEBOUNCE; type < SPRD_EIC_MAX; type++) {
557 		chip = gpiochip_find(&type, sprd_eic_match_chip_by_type);
558 		if (!chip)
559 			continue;
560 
561 		sprd_eic_handle_one_type(chip);
562 	}
563 
564 	chained_irq_exit(ic, desc);
565 }
566 
567 static int sprd_eic_probe(struct platform_device *pdev)
568 {
569 	const struct sprd_eic_variant_data *pdata;
570 	struct gpio_irq_chip *irq;
571 	struct sprd_eic *sprd_eic;
572 	struct resource *res;
573 	int ret, i;
574 
575 	pdata = of_device_get_match_data(&pdev->dev);
576 	if (!pdata) {
577 		dev_err(&pdev->dev, "No matching driver data found.\n");
578 		return -EINVAL;
579 	}
580 
581 	sprd_eic = devm_kzalloc(&pdev->dev, sizeof(*sprd_eic), GFP_KERNEL);
582 	if (!sprd_eic)
583 		return -ENOMEM;
584 
585 	spin_lock_init(&sprd_eic->lock);
586 	sprd_eic->type = pdata->type;
587 
588 	sprd_eic->irq = platform_get_irq(pdev, 0);
589 	if (sprd_eic->irq < 0)
590 		return sprd_eic->irq;
591 
592 	for (i = 0; i < SPRD_EIC_MAX_BANK; i++) {
593 		/*
594 		 * We can have maximum 3 banks EICs, and each EIC has
595 		 * its own base address. But some platform maybe only
596 		 * have one bank EIC, thus base[1] and base[2] can be
597 		 * optional.
598 		 */
599 		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
600 		if (!res)
601 			break;
602 
603 		sprd_eic->base[i] = devm_ioremap_resource(&pdev->dev, res);
604 		if (IS_ERR(sprd_eic->base[i]))
605 			return PTR_ERR(sprd_eic->base[i]);
606 	}
607 
608 	sprd_eic->chip.label = sprd_eic_label_name[sprd_eic->type];
609 	sprd_eic->chip.ngpio = pdata->num_eics;
610 	sprd_eic->chip.base = -1;
611 	sprd_eic->chip.parent = &pdev->dev;
612 	sprd_eic->chip.direction_input = sprd_eic_direction_input;
613 	switch (sprd_eic->type) {
614 	case SPRD_EIC_DEBOUNCE:
615 		sprd_eic->chip.request = sprd_eic_request;
616 		sprd_eic->chip.free = sprd_eic_free;
617 		sprd_eic->chip.set_config = sprd_eic_set_config;
618 		sprd_eic->chip.set = sprd_eic_set;
619 		fallthrough;
620 	case SPRD_EIC_ASYNC:
621 	case SPRD_EIC_SYNC:
622 		sprd_eic->chip.get = sprd_eic_get;
623 		break;
624 	case SPRD_EIC_LATCH:
625 	default:
626 		break;
627 	}
628 
629 	sprd_eic->intc.name = dev_name(&pdev->dev);
630 	sprd_eic->intc.irq_ack = sprd_eic_irq_ack;
631 	sprd_eic->intc.irq_mask = sprd_eic_irq_mask;
632 	sprd_eic->intc.irq_unmask = sprd_eic_irq_unmask;
633 	sprd_eic->intc.irq_set_type = sprd_eic_irq_set_type;
634 	sprd_eic->intc.flags = IRQCHIP_SKIP_SET_WAKE;
635 
636 	irq = &sprd_eic->chip.irq;
637 	irq->chip = &sprd_eic->intc;
638 	irq->handler = handle_bad_irq;
639 	irq->default_type = IRQ_TYPE_NONE;
640 	irq->parent_handler = sprd_eic_irq_handler;
641 	irq->parent_handler_data = sprd_eic;
642 	irq->num_parents = 1;
643 	irq->parents = &sprd_eic->irq;
644 
645 	ret = devm_gpiochip_add_data(&pdev->dev, &sprd_eic->chip, sprd_eic);
646 	if (ret < 0) {
647 		dev_err(&pdev->dev, "Could not register gpiochip %d.\n", ret);
648 		return ret;
649 	}
650 
651 	platform_set_drvdata(pdev, sprd_eic);
652 	return 0;
653 }
654 
655 static const struct of_device_id sprd_eic_of_match[] = {
656 	{
657 		.compatible = "sprd,sc9860-eic-debounce",
658 		.data = &sc9860_eic_dbnc_data,
659 	},
660 	{
661 		.compatible = "sprd,sc9860-eic-latch",
662 		.data = &sc9860_eic_latch_data,
663 	},
664 	{
665 		.compatible = "sprd,sc9860-eic-async",
666 		.data = &sc9860_eic_async_data,
667 	},
668 	{
669 		.compatible = "sprd,sc9860-eic-sync",
670 		.data = &sc9860_eic_sync_data,
671 	},
672 	{
673 		/* end of list */
674 	}
675 };
676 MODULE_DEVICE_TABLE(of, sprd_eic_of_match);
677 
678 static struct platform_driver sprd_eic_driver = {
679 	.probe = sprd_eic_probe,
680 	.driver = {
681 		.name = "sprd-eic",
682 		.of_match_table	= sprd_eic_of_match,
683 	},
684 };
685 
686 module_platform_driver(sprd_eic_driver);
687 
688 MODULE_DESCRIPTION("Spreadtrum EIC driver");
689 MODULE_LICENSE("GPL v2");
690