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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 
sprd_eic_offset_base(struct sprd_eic * sprd_eic,unsigned int bank)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 
sprd_eic_update(struct gpio_chip * chip,unsigned int offset,u16 reg,unsigned int val)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 
sprd_eic_read(struct gpio_chip * chip,unsigned int offset,u16 reg)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 
sprd_eic_request(struct gpio_chip * chip,unsigned int offset)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 
sprd_eic_free(struct gpio_chip * chip,unsigned int offset)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 
sprd_eic_get(struct gpio_chip * chip,unsigned int offset)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 
sprd_eic_direction_input(struct gpio_chip * chip,unsigned int offset)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 
sprd_eic_set(struct gpio_chip * chip,unsigned int offset,int value)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 
sprd_eic_set_debounce(struct gpio_chip * chip,unsigned int offset,unsigned int debounce)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 
sprd_eic_set_config(struct gpio_chip * chip,unsigned int offset,unsigned long config)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 
sprd_eic_irq_mask(struct irq_data * data)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 
sprd_eic_irq_unmask(struct irq_data * data)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 
sprd_eic_irq_ack(struct irq_data * data)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 
sprd_eic_irq_set_type(struct irq_data * data,unsigned int flow_type)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 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IC, 1);
322 			break;
323 		case IRQ_TYPE_LEVEL_LOW:
324 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0);
325 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IC, 1);
326 			break;
327 		case IRQ_TYPE_EDGE_RISING:
328 		case IRQ_TYPE_EDGE_FALLING:
329 		case IRQ_TYPE_EDGE_BOTH:
330 			state = sprd_eic_get(chip, offset);
331 			if (state) {
332 				sprd_eic_update(chip, offset,
333 						SPRD_EIC_DBNC_IEV, 0);
334 				sprd_eic_update(chip, offset,
335 						SPRD_EIC_DBNC_IC, 1);
336 			} else {
337 				sprd_eic_update(chip, offset,
338 						SPRD_EIC_DBNC_IEV, 1);
339 				sprd_eic_update(chip, offset,
340 						SPRD_EIC_DBNC_IC, 1);
341 			}
342 			break;
343 		default:
344 			return -ENOTSUPP;
345 		}
346 
347 		irq_set_handler_locked(data, handle_level_irq);
348 		break;
349 	case SPRD_EIC_LATCH:
350 		switch (flow_type) {
351 		case IRQ_TYPE_LEVEL_HIGH:
352 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 0);
353 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTCLR, 1);
354 			break;
355 		case IRQ_TYPE_LEVEL_LOW:
356 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1);
357 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTCLR, 1);
358 			break;
359 		case IRQ_TYPE_EDGE_RISING:
360 		case IRQ_TYPE_EDGE_FALLING:
361 		case IRQ_TYPE_EDGE_BOTH:
362 			state = sprd_eic_get(chip, offset);
363 			if (state) {
364 				sprd_eic_update(chip, offset,
365 						SPRD_EIC_LATCH_INTPOL, 0);
366 				sprd_eic_update(chip, offset,
367 						SPRD_EIC_LATCH_INTCLR, 1);
368 			} else {
369 				sprd_eic_update(chip, offset,
370 						SPRD_EIC_LATCH_INTPOL, 1);
371 				sprd_eic_update(chip, offset,
372 						SPRD_EIC_LATCH_INTCLR, 1);
373 			}
374 			break;
375 		default:
376 			return -ENOTSUPP;
377 		}
378 
379 		irq_set_handler_locked(data, handle_level_irq);
380 		break;
381 	case SPRD_EIC_ASYNC:
382 		switch (flow_type) {
383 		case IRQ_TYPE_EDGE_RISING:
384 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
385 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 0);
386 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 1);
387 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTCLR, 1);
388 			irq_set_handler_locked(data, handle_edge_irq);
389 			break;
390 		case IRQ_TYPE_EDGE_FALLING:
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, 0);
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_BOTH:
398 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 0);
399 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 1);
400 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTCLR, 1);
401 			irq_set_handler_locked(data, handle_edge_irq);
402 			break;
403 		case IRQ_TYPE_LEVEL_HIGH:
404 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
405 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 1);
406 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 1);
407 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTCLR, 1);
408 			irq_set_handler_locked(data, handle_level_irq);
409 			break;
410 		case IRQ_TYPE_LEVEL_LOW:
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, 0);
414 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTCLR, 1);
415 			irq_set_handler_locked(data, handle_level_irq);
416 			break;
417 		default:
418 			return -ENOTSUPP;
419 		}
420 		break;
421 	case SPRD_EIC_SYNC:
422 		switch (flow_type) {
423 		case IRQ_TYPE_EDGE_RISING:
424 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
425 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
426 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 1);
427 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTCLR, 1);
428 			irq_set_handler_locked(data, handle_edge_irq);
429 			break;
430 		case IRQ_TYPE_EDGE_FALLING:
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, 0);
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_BOTH:
438 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
439 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 1);
440 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTCLR, 1);
441 			irq_set_handler_locked(data, handle_edge_irq);
442 			break;
443 		case IRQ_TYPE_LEVEL_HIGH:
444 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
445 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 1);
446 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 1);
447 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTCLR, 1);
448 			irq_set_handler_locked(data, handle_level_irq);
449 			break;
450 		case IRQ_TYPE_LEVEL_LOW:
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, 0);
454 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTCLR, 1);
455 			irq_set_handler_locked(data, handle_level_irq);
456 			break;
457 		default:
458 			return -ENOTSUPP;
459 		}
460 		break;
461 	default:
462 		dev_err(chip->parent, "Unsupported EIC type.\n");
463 		return -ENOTSUPP;
464 	}
465 
466 	return 0;
467 }
468 
sprd_eic_toggle_trigger(struct gpio_chip * chip,unsigned int irq,unsigned int offset)469 static void sprd_eic_toggle_trigger(struct gpio_chip *chip, unsigned int irq,
470 				    unsigned int offset)
471 {
472 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
473 	struct irq_data *data = irq_get_irq_data(irq);
474 	u32 trigger = irqd_get_trigger_type(data);
475 	int state, post_state;
476 
477 	/*
478 	 * The debounce EIC and latch EIC can only support level trigger, so we
479 	 * can toggle the level trigger to emulate the edge trigger.
480 	 */
481 	if ((sprd_eic->type != SPRD_EIC_DEBOUNCE &&
482 	     sprd_eic->type != SPRD_EIC_LATCH) ||
483 	    !(trigger & IRQ_TYPE_EDGE_BOTH))
484 		return;
485 
486 	sprd_eic_irq_mask(data);
487 	state = sprd_eic_get(chip, offset);
488 
489 retry:
490 	switch (sprd_eic->type) {
491 	case SPRD_EIC_DEBOUNCE:
492 		if (state)
493 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0);
494 		else
495 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 1);
496 		break;
497 	case SPRD_EIC_LATCH:
498 		if (state)
499 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 0);
500 		else
501 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1);
502 		break;
503 	default:
504 		sprd_eic_irq_unmask(data);
505 		return;
506 	}
507 
508 	post_state = sprd_eic_get(chip, offset);
509 	if (state != post_state) {
510 		dev_warn(chip->parent, "EIC level was changed.\n");
511 		state = post_state;
512 		goto retry;
513 	}
514 
515 	sprd_eic_irq_unmask(data);
516 }
517 
sprd_eic_match_chip_by_type(struct gpio_chip * chip,void * data)518 static int sprd_eic_match_chip_by_type(struct gpio_chip *chip, void *data)
519 {
520 	enum sprd_eic_type type = *(enum sprd_eic_type *)data;
521 
522 	return !strcmp(chip->label, sprd_eic_label_name[type]);
523 }
524 
sprd_eic_handle_one_type(struct gpio_chip * chip)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 
sprd_eic_irq_handler(struct irq_desc * desc)567 static void sprd_eic_irq_handler(struct irq_desc *desc)
568 {
569 	struct irq_chip *ic = irq_desc_get_chip(desc);
570 	struct gpio_chip *chip;
571 	enum sprd_eic_type type;
572 
573 	chained_irq_enter(ic, desc);
574 
575 	/*
576 	 * Since the digital-chip EIC 4 sub-modules (debounce, latch, async
577 	 * and sync) share one same interrupt line, we should iterate each
578 	 * EIC module to check if there are EIC interrupts were triggered.
579 	 */
580 	for (type = SPRD_EIC_DEBOUNCE; type < SPRD_EIC_MAX; type++) {
581 		chip = gpiochip_find(&type, sprd_eic_match_chip_by_type);
582 		if (!chip)
583 			continue;
584 
585 		sprd_eic_handle_one_type(chip);
586 	}
587 
588 	chained_irq_exit(ic, desc);
589 }
590 
sprd_eic_probe(struct platform_device * pdev)591 static int sprd_eic_probe(struct platform_device *pdev)
592 {
593 	const struct sprd_eic_variant_data *pdata;
594 	struct gpio_irq_chip *irq;
595 	struct sprd_eic *sprd_eic;
596 	struct resource *res;
597 	int ret, i;
598 
599 	pdata = of_device_get_match_data(&pdev->dev);
600 	if (!pdata) {
601 		dev_err(&pdev->dev, "No matching driver data found.\n");
602 		return -EINVAL;
603 	}
604 
605 	sprd_eic = devm_kzalloc(&pdev->dev, sizeof(*sprd_eic), GFP_KERNEL);
606 	if (!sprd_eic)
607 		return -ENOMEM;
608 
609 	spin_lock_init(&sprd_eic->lock);
610 	sprd_eic->type = pdata->type;
611 
612 	sprd_eic->irq = platform_get_irq(pdev, 0);
613 	if (sprd_eic->irq < 0)
614 		return sprd_eic->irq;
615 
616 	for (i = 0; i < SPRD_EIC_MAX_BANK; i++) {
617 		/*
618 		 * We can have maximum 3 banks EICs, and each EIC has
619 		 * its own base address. But some platform maybe only
620 		 * have one bank EIC, thus base[1] and base[2] can be
621 		 * optional.
622 		 */
623 		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
624 		if (!res)
625 			break;
626 
627 		sprd_eic->base[i] = devm_ioremap_resource(&pdev->dev, res);
628 		if (IS_ERR(sprd_eic->base[i]))
629 			return PTR_ERR(sprd_eic->base[i]);
630 	}
631 
632 	sprd_eic->chip.label = sprd_eic_label_name[sprd_eic->type];
633 	sprd_eic->chip.ngpio = pdata->num_eics;
634 	sprd_eic->chip.base = -1;
635 	sprd_eic->chip.parent = &pdev->dev;
636 	sprd_eic->chip.of_node = pdev->dev.of_node;
637 	sprd_eic->chip.direction_input = sprd_eic_direction_input;
638 	switch (sprd_eic->type) {
639 	case SPRD_EIC_DEBOUNCE:
640 		sprd_eic->chip.request = sprd_eic_request;
641 		sprd_eic->chip.free = sprd_eic_free;
642 		sprd_eic->chip.set_config = sprd_eic_set_config;
643 		sprd_eic->chip.set = sprd_eic_set;
644 		fallthrough;
645 	case SPRD_EIC_ASYNC:
646 	case SPRD_EIC_SYNC:
647 		sprd_eic->chip.get = sprd_eic_get;
648 		break;
649 	case SPRD_EIC_LATCH:
650 	default:
651 		break;
652 	}
653 
654 	sprd_eic->intc.name = dev_name(&pdev->dev);
655 	sprd_eic->intc.irq_ack = sprd_eic_irq_ack;
656 	sprd_eic->intc.irq_mask = sprd_eic_irq_mask;
657 	sprd_eic->intc.irq_unmask = sprd_eic_irq_unmask;
658 	sprd_eic->intc.irq_set_type = sprd_eic_irq_set_type;
659 	sprd_eic->intc.flags = IRQCHIP_SKIP_SET_WAKE;
660 
661 	irq = &sprd_eic->chip.irq;
662 	irq->chip = &sprd_eic->intc;
663 	irq->handler = handle_bad_irq;
664 	irq->default_type = IRQ_TYPE_NONE;
665 	irq->parent_handler = sprd_eic_irq_handler;
666 	irq->parent_handler_data = sprd_eic;
667 	irq->num_parents = 1;
668 	irq->parents = &sprd_eic->irq;
669 
670 	ret = devm_gpiochip_add_data(&pdev->dev, &sprd_eic->chip, sprd_eic);
671 	if (ret < 0) {
672 		dev_err(&pdev->dev, "Could not register gpiochip %d.\n", ret);
673 		return ret;
674 	}
675 
676 	platform_set_drvdata(pdev, sprd_eic);
677 	return 0;
678 }
679 
680 static const struct of_device_id sprd_eic_of_match[] = {
681 	{
682 		.compatible = "sprd,sc9860-eic-debounce",
683 		.data = &sc9860_eic_dbnc_data,
684 	},
685 	{
686 		.compatible = "sprd,sc9860-eic-latch",
687 		.data = &sc9860_eic_latch_data,
688 	},
689 	{
690 		.compatible = "sprd,sc9860-eic-async",
691 		.data = &sc9860_eic_async_data,
692 	},
693 	{
694 		.compatible = "sprd,sc9860-eic-sync",
695 		.data = &sc9860_eic_sync_data,
696 	},
697 	{
698 		/* end of list */
699 	}
700 };
701 MODULE_DEVICE_TABLE(of, sprd_eic_of_match);
702 
703 static struct platform_driver sprd_eic_driver = {
704 	.probe = sprd_eic_probe,
705 	.driver = {
706 		.name = "sprd-eic",
707 		.of_match_table	= sprd_eic_of_match,
708 	},
709 };
710 
711 module_platform_driver(sprd_eic_driver);
712 
713 MODULE_DESCRIPTION("Spreadtrum EIC driver");
714 MODULE_LICENSE("GPL v2");
715