drivers/gpio/gpio-eic-sprd.c - third_party/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2018 Spreadtrum Communications Inc.
  * Copyright (C) 2018 Linaro Ltd.
  */

 #include <linux/bitops.h>
 #include <linux/gpio/driver.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>

 /* EIC registers definition */
 #define SPRD_EIC_DBNC_DATA		0x0
 #define SPRD_EIC_DBNC_DMSK		0x4
 #define SPRD_EIC_DBNC_IEV		0x14
 #define SPRD_EIC_DBNC_IE		0x18
 #define SPRD_EIC_DBNC_RIS		0x1c
 #define SPRD_EIC_DBNC_MIS		0x20
 #define SPRD_EIC_DBNC_IC		0x24
 #define SPRD_EIC_DBNC_TRIG		0x28
 #define SPRD_EIC_DBNC_CTRL0		0x40

 #define SPRD_EIC_LATCH_INTEN		0x0
 #define SPRD_EIC_LATCH_INTRAW		0x4
 #define SPRD_EIC_LATCH_INTMSK		0x8
 #define SPRD_EIC_LATCH_INTCLR		0xc
 #define SPRD_EIC_LATCH_INTPOL		0x10
 #define SPRD_EIC_LATCH_INTMODE		0x14

 #define SPRD_EIC_ASYNC_INTIE		0x0
 #define SPRD_EIC_ASYNC_INTRAW		0x4
 #define SPRD_EIC_ASYNC_INTMSK		0x8
 #define SPRD_EIC_ASYNC_INTCLR		0xc
 #define SPRD_EIC_ASYNC_INTMODE		0x10
 #define SPRD_EIC_ASYNC_INTBOTH		0x14
 #define SPRD_EIC_ASYNC_INTPOL		0x18
 #define SPRD_EIC_ASYNC_DATA		0x1c

 #define SPRD_EIC_SYNC_INTIE		0x0
 #define SPRD_EIC_SYNC_INTRAW		0x4
 #define SPRD_EIC_SYNC_INTMSK		0x8
 #define SPRD_EIC_SYNC_INTCLR		0xc
 #define SPRD_EIC_SYNC_INTMODE		0x10
 #define SPRD_EIC_SYNC_INTBOTH		0x14
 #define SPRD_EIC_SYNC_INTPOL		0x18
 #define SPRD_EIC_SYNC_DATA		0x1c

 /*
  * The digital-chip EIC controller can support maximum 3 banks, and each bank
  * contains 8 EICs.
  */
 #define SPRD_EIC_MAX_BANK		3
 #define SPRD_EIC_PER_BANK_NR		8
 #define SPRD_EIC_DATA_MASK		GENMASK(7, 0)
 #define SPRD_EIC_BIT(x)			((x) & (SPRD_EIC_PER_BANK_NR - 1))
 #define SPRD_EIC_DBNC_MASK		GENMASK(11, 0)

 /*
  * The Spreadtrum EIC (external interrupt controller) can be used only in
  * input mode to generate interrupts if detecting input signals.
  *
  * The Spreadtrum digital-chip EIC controller contains 4 sub-modules:
  * debounce EIC, latch EIC, async EIC and sync EIC,
  *
  * The debounce EIC is used to capture the input signals' stable status
  * (millisecond resolution) and a single-trigger mechanism is introduced
  * into this sub-module to enhance the input event detection reliability.
  * The debounce range is from 1ms to 4s with a step size of 1ms.
  *
  * The latch EIC is used to latch some special power down signals and
  * generate interrupts, since the latch EIC does not depend on the APB clock
  * to capture signals.
  *
  * The async EIC uses a 32k clock to capture the short signals (microsecond
  * resolution) to generate interrupts by level or edge trigger.
  *
  * The EIC-sync is similar with GPIO's input function, which is a synchronized
  * signal input register.
  */
 enum sprd_eic_type {
 	SPRD_EIC_DEBOUNCE,
 	SPRD_EIC_LATCH,
 	SPRD_EIC_ASYNC,
 	SPRD_EIC_SYNC,
 	SPRD_EIC_MAX,
 };

 struct sprd_eic {
 	struct gpio_chip chip;
 	void __iomem *base[SPRD_EIC_MAX_BANK];
 	enum sprd_eic_type type;
 	spinlock_t lock;
 	int irq;
 };

 struct sprd_eic_variant_data {
 	enum sprd_eic_type type;
 	u32 num_eics;
 };

 static const char *sprd_eic_label_name[SPRD_EIC_MAX] = {
 	"eic-debounce", "eic-latch", "eic-async",
 	"eic-sync",
 };

 static const struct sprd_eic_variant_data sc9860_eic_dbnc_data = {
 	.type = SPRD_EIC_DEBOUNCE,
 	.num_eics = 8,
 };

 static const struct sprd_eic_variant_data sc9860_eic_latch_data = {
 	.type = SPRD_EIC_LATCH,
 	.num_eics = 8,
 };

 static const struct sprd_eic_variant_data sc9860_eic_async_data = {
 	.type = SPRD_EIC_ASYNC,
 	.num_eics = 8,
 };

 static const struct sprd_eic_variant_data sc9860_eic_sync_data = {
 	.type = SPRD_EIC_SYNC,
 	.num_eics = 8,
 };

 static inline void __iomem *sprd_eic_offset_base(struct sprd_eic *sprd_eic,
 						 unsigned int bank)
 {
 	if (bank >= SPRD_EIC_MAX_BANK)
 		return NULL;

 	return sprd_eic->base[bank];
 }

 static void sprd_eic_update(struct gpio_chip *chip, unsigned int offset,
 			    u16 reg, unsigned int val)
 {
 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
 	void __iomem *base =
 		sprd_eic_offset_base(sprd_eic, offset / SPRD_EIC_PER_BANK_NR);
 	unsigned long flags;
 	u32 tmp;

 	spin_lock_irqsave(&sprd_eic->lock, flags);
 	tmp = readl_relaxed(base + reg);

 	if (val)
 		tmp |= BIT(SPRD_EIC_BIT(offset));
 	else
 		tmp &= ~BIT(SPRD_EIC_BIT(offset));

 	writel_relaxed(tmp, base + reg);
 	spin_unlock_irqrestore(&sprd_eic->lock, flags);
 }

 static int sprd_eic_read(struct gpio_chip *chip, unsigned int offset, u16 reg)
 {
 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
 	void __iomem *base =
 		sprd_eic_offset_base(sprd_eic, offset / SPRD_EIC_PER_BANK_NR);

 	return !!(readl_relaxed(base + reg) & BIT(SPRD_EIC_BIT(offset)));
 }

 static int sprd_eic_request(struct gpio_chip *chip, unsigned int offset)
 {
 	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_DMSK, 1);
 	return 0;
 }

 static void sprd_eic_free(struct gpio_chip *chip, unsigned int offset)
 {
 	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_DMSK, 0);
 }

 static int sprd_eic_get(struct gpio_chip *chip, unsigned int offset)
 {
 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);

 	switch (sprd_eic->type) {
 	case SPRD_EIC_DEBOUNCE:
 		return sprd_eic_read(chip, offset, SPRD_EIC_DBNC_DATA);
 	case SPRD_EIC_ASYNC:
 		return sprd_eic_read(chip, offset, SPRD_EIC_ASYNC_DATA);
 	case SPRD_EIC_SYNC:
 		return sprd_eic_read(chip, offset, SPRD_EIC_SYNC_DATA);
 	default:
 		return -ENOTSUPP;
 	}
 }

 static int sprd_eic_direction_input(struct gpio_chip *chip, unsigned int offset)
 {
 	/* EICs are always input, nothing need to do here. */
 	return 0;
 }

 static void sprd_eic_set(struct gpio_chip *chip, unsigned int offset, int value)
 {
 	/* EICs are always input, nothing need to do here. */
 }

 static int sprd_eic_set_debounce(struct gpio_chip *chip, unsigned int offset,
 				 unsigned int debounce)
 {
 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
 	void __iomem *base =
 		sprd_eic_offset_base(sprd_eic, offset / SPRD_EIC_PER_BANK_NR);
 	u32 reg = SPRD_EIC_DBNC_CTRL0 + SPRD_EIC_BIT(offset) * 0x4;
 	u32 value = readl_relaxed(base + reg) & ~SPRD_EIC_DBNC_MASK;

 	value |= (debounce / 1000) & SPRD_EIC_DBNC_MASK;
 	writel_relaxed(value, base + reg);

 	return 0;
 }

 static int sprd_eic_set_config(struct gpio_chip *chip, unsigned int offset,
 			       unsigned long config)
 {
 	unsigned long param = pinconf_to_config_param(config);
 	u32 arg = pinconf_to_config_argument(config);

 	if (param == PIN_CONFIG_INPUT_DEBOUNCE)
 		return sprd_eic_set_debounce(chip, offset, arg);

 	return -ENOTSUPP;
 }

 static void sprd_eic_irq_mask(struct irq_data *data)
 {
 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
 	u32 offset = irqd_to_hwirq(data);

 	switch (sprd_eic->type) {
 	case SPRD_EIC_DEBOUNCE:
 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IE, 0);
 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_TRIG, 0);
 		break;
 	case SPRD_EIC_LATCH:
 		sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTEN, 0);
 		break;
 	case SPRD_EIC_ASYNC:
 		sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTIE, 0);
 		break;
 	case SPRD_EIC_SYNC:
 		sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTIE, 0);
 		break;
 	default:
 		dev_err(chip->parent, "Unsupported EIC type.\n");
 	}

 	gpiochip_disable_irq(chip, offset);
 }

 static void sprd_eic_irq_unmask(struct irq_data *data)
 {
 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
 	u32 offset = irqd_to_hwirq(data);

 	gpiochip_enable_irq(chip, offset);

 	switch (sprd_eic->type) {
 	case SPRD_EIC_DEBOUNCE:
 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IE, 1);
 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_TRIG, 1);
 		break;
 	case SPRD_EIC_LATCH:
 		sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTEN, 1);
 		break;
 	case SPRD_EIC_ASYNC:
 		sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTIE, 1);
 		break;
 	case SPRD_EIC_SYNC:
 		sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTIE, 1);
 		break;
 	default:
 		dev_err(chip->parent, "Unsupported EIC type.\n");
 	}
 }

 static void sprd_eic_irq_ack(struct irq_data *data)
 {
 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
 	u32 offset = irqd_to_hwirq(data);

 	switch (sprd_eic->type) {
 	case SPRD_EIC_DEBOUNCE:
 		sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IC, 1);
 		break;
 	case SPRD_EIC_LATCH:
 		sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTCLR, 1);
 		break;
 	case SPRD_EIC_ASYNC:
 		sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTCLR, 1);
 		break;
 	case SPRD_EIC_SYNC:
 		sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTCLR, 1);
 		break;
 	default:
 		dev_err(chip->parent, "Unsupported EIC type.\n");
 	}
 }

 static int sprd_eic_irq_set_type(struct irq_data *data, unsigned int flow_type)
 {
 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
 	u32 offset = irqd_to_hwirq(data);
 	int state;

 	switch (sprd_eic->type) {
 	case SPRD_EIC_DEBOUNCE:
 		switch (flow_type) {
 		case IRQ_TYPE_LEVEL_HIGH:
 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 1);
 			break;
 		case IRQ_TYPE_LEVEL_LOW:
 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0);
 			break;
 		case IRQ_TYPE_EDGE_RISING:
 		case IRQ_TYPE_EDGE_FALLING:
 		case IRQ_TYPE_EDGE_BOTH:
 			state = sprd_eic_get(chip, offset);
 			if (state)
 				sprd_eic_update(chip, offset,
 						SPRD_EIC_DBNC_IEV, 0);
 			else
 				sprd_eic_update(chip, offset,
 						SPRD_EIC_DBNC_IEV, 1);
 			break;
 		default:
 			return -ENOTSUPP;
 		}

 		irq_set_handler_locked(data, handle_level_irq);
 		break;
 	case SPRD_EIC_LATCH:
 		switch (flow_type) {
 		case IRQ_TYPE_LEVEL_HIGH:
 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 0);
 			break;
 		case IRQ_TYPE_LEVEL_LOW:
 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1);
 			break;
 		case IRQ_TYPE_EDGE_RISING:
 		case IRQ_TYPE_EDGE_FALLING:
 		case IRQ_TYPE_EDGE_BOTH:
 			state = sprd_eic_get(chip, offset);
 			if (state)
 				sprd_eic_update(chip, offset,
 						SPRD_EIC_LATCH_INTPOL, 0);
 			else
 				sprd_eic_update(chip, offset,
 						SPRD_EIC_LATCH_INTPOL, 1);
 			break;
 		default:
 			return -ENOTSUPP;
 		}

 		irq_set_handler_locked(data, handle_level_irq);
 		break;
 	case SPRD_EIC_ASYNC:
 		switch (flow_type) {
 		case IRQ_TYPE_EDGE_RISING:
 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 0);
 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 1);
 			irq_set_handler_locked(data, handle_edge_irq);
 			break;
 		case IRQ_TYPE_EDGE_FALLING:
 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 0);
 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 0);
 			irq_set_handler_locked(data, handle_edge_irq);
 			break;
 		case IRQ_TYPE_EDGE_BOTH:
 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 0);
 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 1);
 			irq_set_handler_locked(data, handle_edge_irq);
 			break;
 		case IRQ_TYPE_LEVEL_HIGH:
 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 1);
 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 1);
 			irq_set_handler_locked(data, handle_level_irq);
 			break;
 		case IRQ_TYPE_LEVEL_LOW:
 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 1);
 			sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 0);
 			irq_set_handler_locked(data, handle_level_irq);
 			break;
 		default:
 			return -ENOTSUPP;
 		}
 		break;
 	case SPRD_EIC_SYNC:
 		switch (flow_type) {
 		case IRQ_TYPE_EDGE_RISING:
 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 1);
 			irq_set_handler_locked(data, handle_edge_irq);
 			break;
 		case IRQ_TYPE_EDGE_FALLING:
 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 0);
 			irq_set_handler_locked(data, handle_edge_irq);
 			break;
 		case IRQ_TYPE_EDGE_BOTH:
 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 1);
 			irq_set_handler_locked(data, handle_edge_irq);
 			break;
 		case IRQ_TYPE_LEVEL_HIGH:
 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 1);
 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 1);
 			irq_set_handler_locked(data, handle_level_irq);
 			break;
 		case IRQ_TYPE_LEVEL_LOW:
 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 1);
 			sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 0);
 			irq_set_handler_locked(data, handle_level_irq);
 			break;
 		default:
 			return -ENOTSUPP;
 		}
 		break;
 	default:
 		dev_err(chip->parent, "Unsupported EIC type.\n");
 		return -ENOTSUPP;
 	}

 	return 0;
 }

 static void sprd_eic_toggle_trigger(struct gpio_chip *chip, unsigned int irq,
 				    unsigned int offset)
 {
 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
 	struct irq_data *data = irq_get_irq_data(irq);
 	u32 trigger = irqd_get_trigger_type(data);
 	int state, post_state;

 	/*
 	 * The debounce EIC and latch EIC can only support level trigger, so we
 	 * can toggle the level trigger to emulate the edge trigger.
 	 */
 	if ((sprd_eic->type != SPRD_EIC_DEBOUNCE &&
 	     sprd_eic->type != SPRD_EIC_LATCH) ||
 	    !(trigger & IRQ_TYPE_EDGE_BOTH))
 		return;

 	sprd_eic_irq_mask(data);
 	state = sprd_eic_get(chip, offset);

 retry:
 	switch (sprd_eic->type) {
 	case SPRD_EIC_DEBOUNCE:
 		if (state)
 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0);
 		else
 			sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 1);
 		break;
 	case SPRD_EIC_LATCH:
 		if (state)
 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 0);
 		else
 			sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1);
 		break;
 	default:
 		sprd_eic_irq_unmask(data);
 		return;
 	}

 	post_state = sprd_eic_get(chip, offset);
 	if (state != post_state) {
 		dev_warn(chip->parent, "EIC level was changed.\n");
 		state = post_state;
 		goto retry;
 	}

 	sprd_eic_irq_unmask(data);
 }

 static int sprd_eic_match_chip_by_type(struct gpio_chip *chip, void *data)
 {
 	enum sprd_eic_type type = *(enum sprd_eic_type *)data;

 	return !strcmp(chip->label, sprd_eic_label_name[type]);
 }

 static void sprd_eic_handle_one_type(struct gpio_chip *chip)
 {
 	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
 	u32 bank, n, girq;

 	for (bank = 0; bank * SPRD_EIC_PER_BANK_NR < chip->ngpio; bank++) {
 		void __iomem *base = sprd_eic_offset_base(sprd_eic, bank);
 		unsigned long reg;

 		switch (sprd_eic->type) {
 		case SPRD_EIC_DEBOUNCE:
 			reg = readl_relaxed(base + SPRD_EIC_DBNC_MIS) &
 				SPRD_EIC_DATA_MASK;
 			break;
 		case SPRD_EIC_LATCH:
 			reg = readl_relaxed(base + SPRD_EIC_LATCH_INTMSK) &
 				SPRD_EIC_DATA_MASK;
 			break;
 		case SPRD_EIC_ASYNC:
 			reg = readl_relaxed(base + SPRD_EIC_ASYNC_INTMSK) &
 				SPRD_EIC_DATA_MASK;
 			break;
 		case SPRD_EIC_SYNC:
 			reg = readl_relaxed(base + SPRD_EIC_SYNC_INTMSK) &
 				SPRD_EIC_DATA_MASK;
 			break;
 		default:
 			dev_err(chip->parent, "Unsupported EIC type.\n");
 			return;
 		}

 		for_each_set_bit(n, &reg, SPRD_EIC_PER_BANK_NR) {
 			u32 offset = bank * SPRD_EIC_PER_BANK_NR + n;

 			girq = irq_find_mapping(chip->irq.domain, offset);

 			generic_handle_irq(girq);
 			sprd_eic_toggle_trigger(chip, girq, offset);
 		}
 	}
 }

 static void sprd_eic_irq_handler(struct irq_desc *desc)
 {
 	struct irq_chip *ic = irq_desc_get_chip(desc);
 	struct gpio_chip *chip;
 	enum sprd_eic_type type;

 	chained_irq_enter(ic, desc);

 	/*
 	 * Since the digital-chip EIC 4 sub-modules (debounce, latch, async
 	 * and sync) share one same interrupt line, we should iterate each
 	 * EIC module to check if there are EIC interrupts were triggered.
 	 */
 	for (type = SPRD_EIC_DEBOUNCE; type < SPRD_EIC_MAX; type++) {
 		chip = gpiochip_find(&type, sprd_eic_match_chip_by_type);
 		if (!chip)
 			continue;

 		sprd_eic_handle_one_type(chip);
 	}

 	chained_irq_exit(ic, desc);
 }

 static const struct irq_chip sprd_eic_irq = {
 	.name		= "sprd-eic",
 	.irq_ack	= sprd_eic_irq_ack,
 	.irq_mask	= sprd_eic_irq_mask,
 	.irq_unmask	= sprd_eic_irq_unmask,
 	.irq_set_type	= sprd_eic_irq_set_type,
 	.flags		= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_IMMUTABLE,
 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
 };
 static int sprd_eic_probe(struct platform_device *pdev)
 {
 	const struct sprd_eic_variant_data *pdata;
 	struct gpio_irq_chip *irq;
 	struct sprd_eic *sprd_eic;
 	struct resource *res;
 	int ret, i;

 	pdata = of_device_get_match_data(&pdev->dev);
 	if (!pdata) {
 		dev_err(&pdev->dev, "No matching driver data found.\n");
 		return -EINVAL;
 	}

 	sprd_eic = devm_kzalloc(&pdev->dev, sizeof(*sprd_eic), GFP_KERNEL);
 	if (!sprd_eic)
 		return -ENOMEM;

 	spin_lock_init(&sprd_eic->lock);
 	sprd_eic->type = pdata->type;

 	sprd_eic->irq = platform_get_irq(pdev, 0);
 	if (sprd_eic->irq < 0)
 		return sprd_eic->irq;

 	for (i = 0; i < SPRD_EIC_MAX_BANK; i++) {
 		/*
 		 * We can have maximum 3 banks EICs, and each EIC has
 		 * its own base address. But some platform maybe only
 		 * have one bank EIC, thus base[1] and base[2] can be
 		 * optional.
 		 */
 		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 		if (!res)
 			break;

 		sprd_eic->base[i] = devm_ioremap_resource(&pdev->dev, res);
 		if (IS_ERR(sprd_eic->base[i]))
 			return PTR_ERR(sprd_eic->base[i]);
 	}

 	sprd_eic->chip.label = sprd_eic_label_name[sprd_eic->type];
 	sprd_eic->chip.ngpio = pdata->num_eics;
 	sprd_eic->chip.base = -1;
 	sprd_eic->chip.parent = &pdev->dev;
 	sprd_eic->chip.direction_input = sprd_eic_direction_input;
 	switch (sprd_eic->type) {
 	case SPRD_EIC_DEBOUNCE:
 		sprd_eic->chip.request = sprd_eic_request;
 		sprd_eic->chip.free = sprd_eic_free;
 		sprd_eic->chip.set_config = sprd_eic_set_config;
 		sprd_eic->chip.set = sprd_eic_set;
 		fallthrough;
 	case SPRD_EIC_ASYNC:
 	case SPRD_EIC_SYNC:
 		sprd_eic->chip.get = sprd_eic_get;
 		break;
 	case SPRD_EIC_LATCH:
 	default:
 		break;
 	}

 	irq = &sprd_eic->chip.irq;
 	gpio_irq_chip_set_chip(irq, &sprd_eic_irq);
 	irq->handler = handle_bad_irq;
 	irq->default_type = IRQ_TYPE_NONE;
 	irq->parent_handler = sprd_eic_irq_handler;
 	irq->parent_handler_data = sprd_eic;
 	irq->num_parents = 1;
 	irq->parents = &sprd_eic->irq;

 	ret = devm_gpiochip_add_data(&pdev->dev, &sprd_eic->chip, sprd_eic);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "Could not register gpiochip %d.\n", ret);
 		return ret;
 	}

 	platform_set_drvdata(pdev, sprd_eic);
 	return 0;
 }

 static const struct of_device_id sprd_eic_of_match[] = {
 	{
 		.compatible = "sprd,sc9860-eic-debounce",
 		.data = &sc9860_eic_dbnc_data,
 	},
 	{
 		.compatible = "sprd,sc9860-eic-latch",
 		.data = &sc9860_eic_latch_data,
 	},
 	{
 		.compatible = "sprd,sc9860-eic-async",
 		.data = &sc9860_eic_async_data,
 	},
 	{
 		.compatible = "sprd,sc9860-eic-sync",
 		.data = &sc9860_eic_sync_data,
 	},
 	{
 		/* end of list */
 	}
 };
 MODULE_DEVICE_TABLE(of, sprd_eic_of_match);

 static struct platform_driver sprd_eic_driver = {
 	.probe = sprd_eic_probe,
 	.driver = {
 		.name = "sprd-eic",
 		.of_match_table	= sprd_eic_of_match,
 	},
 };

 module_platform_driver(sprd_eic_driver);

 MODULE_DESCRIPTION("Spreadtrum EIC driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (C) 2018 Spreadtrum Communications Inc.
	* Copyright (C) 2018 Linaro Ltd.
	*/

	#include <linux/bitops.h>
	#include <linux/gpio/driver.h>
	#include <linux/interrupt.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/of_device.h>
	#include <linux/platform_device.h>
	#include <linux/spinlock.h>

	/* EIC registers definition */
	#define SPRD_EIC_DBNC_DATA 0x0
	#define SPRD_EIC_DBNC_DMSK 0x4
	#define SPRD_EIC_DBNC_IEV 0x14
	#define SPRD_EIC_DBNC_IE 0x18
	#define SPRD_EIC_DBNC_RIS 0x1c
	#define SPRD_EIC_DBNC_MIS 0x20
	#define SPRD_EIC_DBNC_IC 0x24
	#define SPRD_EIC_DBNC_TRIG 0x28
	#define SPRD_EIC_DBNC_CTRL0 0x40

	#define SPRD_EIC_LATCH_INTEN 0x0
	#define SPRD_EIC_LATCH_INTRAW 0x4
	#define SPRD_EIC_LATCH_INTMSK 0x8
	#define SPRD_EIC_LATCH_INTCLR 0xc
	#define SPRD_EIC_LATCH_INTPOL 0x10
	#define SPRD_EIC_LATCH_INTMODE 0x14

	#define SPRD_EIC_ASYNC_INTIE 0x0
	#define SPRD_EIC_ASYNC_INTRAW 0x4
	#define SPRD_EIC_ASYNC_INTMSK 0x8
	#define SPRD_EIC_ASYNC_INTCLR 0xc
	#define SPRD_EIC_ASYNC_INTMODE 0x10
	#define SPRD_EIC_ASYNC_INTBOTH 0x14
	#define SPRD_EIC_ASYNC_INTPOL 0x18
	#define SPRD_EIC_ASYNC_DATA 0x1c

	#define SPRD_EIC_SYNC_INTIE 0x0
	#define SPRD_EIC_SYNC_INTRAW 0x4
	#define SPRD_EIC_SYNC_INTMSK 0x8
	#define SPRD_EIC_SYNC_INTCLR 0xc
	#define SPRD_EIC_SYNC_INTMODE 0x10
	#define SPRD_EIC_SYNC_INTBOTH 0x14
	#define SPRD_EIC_SYNC_INTPOL 0x18
	#define SPRD_EIC_SYNC_DATA 0x1c

	/*
	* The digital-chip EIC controller can support maximum 3 banks, and each bank
	* contains 8 EICs.
	*/
	#define SPRD_EIC_MAX_BANK 3
	#define SPRD_EIC_PER_BANK_NR 8
	#define SPRD_EIC_DATA_MASK GENMASK(7, 0)
	#define SPRD_EIC_BIT(x) ((x) & (SPRD_EIC_PER_BANK_NR - 1))
	#define SPRD_EIC_DBNC_MASK GENMASK(11, 0)

	/*
	* The Spreadtrum EIC (external interrupt controller) can be used only in
	* input mode to generate interrupts if detecting input signals.
	*
	* The Spreadtrum digital-chip EIC controller contains 4 sub-modules:
	* debounce EIC, latch EIC, async EIC and sync EIC,
	*
	* The debounce EIC is used to capture the input signals' stable status
	* (millisecond resolution) and a single-trigger mechanism is introduced
	* into this sub-module to enhance the input event detection reliability.
	* The debounce range is from 1ms to 4s with a step size of 1ms.
	*
	* The latch EIC is used to latch some special power down signals and
	* generate interrupts, since the latch EIC does not depend on the APB clock
	* to capture signals.
	*
	* The async EIC uses a 32k clock to capture the short signals (microsecond
	* resolution) to generate interrupts by level or edge trigger.
	*
	* The EIC-sync is similar with GPIO's input function, which is a synchronized
	* signal input register.
	*/
	enum sprd_eic_type {
	SPRD_EIC_DEBOUNCE,
	SPRD_EIC_LATCH,
	SPRD_EIC_ASYNC,
	SPRD_EIC_SYNC,
	SPRD_EIC_MAX,
	};

	struct sprd_eic {
	struct gpio_chip chip;
	void __iomem *base[SPRD_EIC_MAX_BANK];
	enum sprd_eic_type type;
	spinlock_t lock;
	int irq;
	};

	struct sprd_eic_variant_data {
	enum sprd_eic_type type;
	u32 num_eics;
	};

	static const char *sprd_eic_label_name[SPRD_EIC_MAX] = {
	"eic-debounce", "eic-latch", "eic-async",
	"eic-sync",
	};

	static const struct sprd_eic_variant_data sc9860_eic_dbnc_data = {
	.type = SPRD_EIC_DEBOUNCE,
	.num_eics = 8,
	};

	static const struct sprd_eic_variant_data sc9860_eic_latch_data = {
	.type = SPRD_EIC_LATCH,
	.num_eics = 8,
	};

	static const struct sprd_eic_variant_data sc9860_eic_async_data = {
	.type = SPRD_EIC_ASYNC,
	.num_eics = 8,
	};

	static const struct sprd_eic_variant_data sc9860_eic_sync_data = {
	.type = SPRD_EIC_SYNC,
	.num_eics = 8,
	};

	static inline void __iomem sprd_eic_offset_base(struct sprd_eic sprd_eic,
	unsigned int bank)
	{
	if (bank >= SPRD_EIC_MAX_BANK)
	return NULL;

	return sprd_eic->base[bank];
	}

	static void sprd_eic_update(struct gpio_chip *chip, unsigned int offset,
	u16 reg, unsigned int val)
	{
	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
	void __iomem *base =
	sprd_eic_offset_base(sprd_eic, offset / SPRD_EIC_PER_BANK_NR);
	unsigned long flags;
	u32 tmp;

	spin_lock_irqsave(&sprd_eic->lock, flags);
	tmp = readl_relaxed(base + reg);

	if (val)
	tmp \|= BIT(SPRD_EIC_BIT(offset));
	else
	tmp &= ~BIT(SPRD_EIC_BIT(offset));

	writel_relaxed(tmp, base + reg);
	spin_unlock_irqrestore(&sprd_eic->lock, flags);
	}

	static int sprd_eic_read(struct gpio_chip *chip, unsigned int offset, u16 reg)
	{
	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
	void __iomem *base =
	sprd_eic_offset_base(sprd_eic, offset / SPRD_EIC_PER_BANK_NR);

	return !!(readl_relaxed(base + reg) & BIT(SPRD_EIC_BIT(offset)));
	}

	static int sprd_eic_request(struct gpio_chip *chip, unsigned int offset)
	{
	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_DMSK, 1);
	return 0;
	}

	static void sprd_eic_free(struct gpio_chip *chip, unsigned int offset)
	{
	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_DMSK, 0);
	}

	static int sprd_eic_get(struct gpio_chip *chip, unsigned int offset)
	{
	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);

	switch (sprd_eic->type) {
	case SPRD_EIC_DEBOUNCE:
	return sprd_eic_read(chip, offset, SPRD_EIC_DBNC_DATA);
	case SPRD_EIC_ASYNC:
	return sprd_eic_read(chip, offset, SPRD_EIC_ASYNC_DATA);
	case SPRD_EIC_SYNC:
	return sprd_eic_read(chip, offset, SPRD_EIC_SYNC_DATA);
	default:
	return -ENOTSUPP;
	}
	}

	static int sprd_eic_direction_input(struct gpio_chip *chip, unsigned int offset)
	{
	/* EICs are always input, nothing need to do here. */
	return 0;
	}

	static void sprd_eic_set(struct gpio_chip *chip, unsigned int offset, int value)
	{
	/* EICs are always input, nothing need to do here. */
	}

	static int sprd_eic_set_debounce(struct gpio_chip *chip, unsigned int offset,
	unsigned int debounce)
	{
	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
	void __iomem *base =
	sprd_eic_offset_base(sprd_eic, offset / SPRD_EIC_PER_BANK_NR);
	u32 reg = SPRD_EIC_DBNC_CTRL0 + SPRD_EIC_BIT(offset) * 0x4;
	u32 value = readl_relaxed(base + reg) & ~SPRD_EIC_DBNC_MASK;

	value \|= (debounce / 1000) & SPRD_EIC_DBNC_MASK;
	writel_relaxed(value, base + reg);

	return 0;
	}

	static int sprd_eic_set_config(struct gpio_chip *chip, unsigned int offset,
	unsigned long config)
	{
	unsigned long param = pinconf_to_config_param(config);
	u32 arg = pinconf_to_config_argument(config);

	if (param == PIN_CONFIG_INPUT_DEBOUNCE)
	return sprd_eic_set_debounce(chip, offset, arg);

	return -ENOTSUPP;
	}

	static void sprd_eic_irq_mask(struct irq_data *data)
	{
	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
	u32 offset = irqd_to_hwirq(data);

	switch (sprd_eic->type) {
	case SPRD_EIC_DEBOUNCE:
	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IE, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_TRIG, 0);
	break;
	case SPRD_EIC_LATCH:
	sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTEN, 0);
	break;
	case SPRD_EIC_ASYNC:
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTIE, 0);
	break;
	case SPRD_EIC_SYNC:
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTIE, 0);
	break;
	default:
	dev_err(chip->parent, "Unsupported EIC type.\n");
	}

	gpiochip_disable_irq(chip, offset);
	}

	static void sprd_eic_irq_unmask(struct irq_data *data)
	{
	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
	u32 offset = irqd_to_hwirq(data);

	gpiochip_enable_irq(chip, offset);

	switch (sprd_eic->type) {
	case SPRD_EIC_DEBOUNCE:
	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IE, 1);
	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_TRIG, 1);
	break;
	case SPRD_EIC_LATCH:
	sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTEN, 1);
	break;
	case SPRD_EIC_ASYNC:
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTIE, 1);
	break;
	case SPRD_EIC_SYNC:
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTIE, 1);
	break;
	default:
	dev_err(chip->parent, "Unsupported EIC type.\n");
	}
	}

	static void sprd_eic_irq_ack(struct irq_data *data)
	{
	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
	u32 offset = irqd_to_hwirq(data);

	switch (sprd_eic->type) {
	case SPRD_EIC_DEBOUNCE:
	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IC, 1);
	break;
	case SPRD_EIC_LATCH:
	sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTCLR, 1);
	break;
	case SPRD_EIC_ASYNC:
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTCLR, 1);
	break;
	case SPRD_EIC_SYNC:
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTCLR, 1);
	break;
	default:
	dev_err(chip->parent, "Unsupported EIC type.\n");
	}
	}

	static int sprd_eic_irq_set_type(struct irq_data *data, unsigned int flow_type)
	{
	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
	u32 offset = irqd_to_hwirq(data);
	int state;

	switch (sprd_eic->type) {
	case SPRD_EIC_DEBOUNCE:
	switch (flow_type) {
	case IRQ_TYPE_LEVEL_HIGH:
	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 1);
	break;
	case IRQ_TYPE_LEVEL_LOW:
	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0);
	break;
	case IRQ_TYPE_EDGE_RISING:
	case IRQ_TYPE_EDGE_FALLING:
	case IRQ_TYPE_EDGE_BOTH:
	state = sprd_eic_get(chip, offset);
	if (state)
	sprd_eic_update(chip, offset,
	SPRD_EIC_DBNC_IEV, 0);
	else
	sprd_eic_update(chip, offset,
	SPRD_EIC_DBNC_IEV, 1);
	break;
	default:
	return -ENOTSUPP;
	}

	irq_set_handler_locked(data, handle_level_irq);
	break;
	case SPRD_EIC_LATCH:
	switch (flow_type) {
	case IRQ_TYPE_LEVEL_HIGH:
	sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 0);
	break;
	case IRQ_TYPE_LEVEL_LOW:
	sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1);
	break;
	case IRQ_TYPE_EDGE_RISING:
	case IRQ_TYPE_EDGE_FALLING:
	case IRQ_TYPE_EDGE_BOTH:
	state = sprd_eic_get(chip, offset);
	if (state)
	sprd_eic_update(chip, offset,
	SPRD_EIC_LATCH_INTPOL, 0);
	else
	sprd_eic_update(chip, offset,
	SPRD_EIC_LATCH_INTPOL, 1);
	break;
	default:
	return -ENOTSUPP;
	}

	irq_set_handler_locked(data, handle_level_irq);
	break;
	case SPRD_EIC_ASYNC:
	switch (flow_type) {
	case IRQ_TYPE_EDGE_RISING:
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 1);
	irq_set_handler_locked(data, handle_edge_irq);
	break;
	case IRQ_TYPE_EDGE_FALLING:
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 0);
	irq_set_handler_locked(data, handle_edge_irq);
	break;
	case IRQ_TYPE_EDGE_BOTH:
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 1);
	irq_set_handler_locked(data, handle_edge_irq);
	break;
	case IRQ_TYPE_LEVEL_HIGH:
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 1);
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 1);
	irq_set_handler_locked(data, handle_level_irq);
	break;
	case IRQ_TYPE_LEVEL_LOW:
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 1);
	sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 0);
	irq_set_handler_locked(data, handle_level_irq);
	break;
	default:
	return -ENOTSUPP;
	}
	break;
	case SPRD_EIC_SYNC:
	switch (flow_type) {
	case IRQ_TYPE_EDGE_RISING:
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 1);
	irq_set_handler_locked(data, handle_edge_irq);
	break;
	case IRQ_TYPE_EDGE_FALLING:
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 0);
	irq_set_handler_locked(data, handle_edge_irq);
	break;
	case IRQ_TYPE_EDGE_BOTH:
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 1);
	irq_set_handler_locked(data, handle_edge_irq);
	break;
	case IRQ_TYPE_LEVEL_HIGH:
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 1);
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 1);
	irq_set_handler_locked(data, handle_level_irq);
	break;
	case IRQ_TYPE_LEVEL_LOW:
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 1);
	sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 0);
	irq_set_handler_locked(data, handle_level_irq);
	break;
	default:
	return -ENOTSUPP;
	}
	break;
	default:
	dev_err(chip->parent, "Unsupported EIC type.\n");
	return -ENOTSUPP;
	}

	return 0;
	}

	static void sprd_eic_toggle_trigger(struct gpio_chip *chip, unsigned int irq,
	unsigned int offset)
	{
	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
	struct irq_data *data = irq_get_irq_data(irq);
	u32 trigger = irqd_get_trigger_type(data);
	int state, post_state;

	/*
	* The debounce EIC and latch EIC can only support level trigger, so we
	* can toggle the level trigger to emulate the edge trigger.
	*/
	if ((sprd_eic->type != SPRD_EIC_DEBOUNCE &&
	sprd_eic->type != SPRD_EIC_LATCH) \|\|
	!(trigger & IRQ_TYPE_EDGE_BOTH))
	return;

	sprd_eic_irq_mask(data);
	state = sprd_eic_get(chip, offset);

	retry:
	switch (sprd_eic->type) {
	case SPRD_EIC_DEBOUNCE:
	if (state)
	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0);
	else
	sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 1);
	break;
	case SPRD_EIC_LATCH:
	if (state)
	sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 0);
	else
	sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1);
	break;
	default:
	sprd_eic_irq_unmask(data);
	return;
	}

	post_state = sprd_eic_get(chip, offset);
	if (state != post_state) {
	dev_warn(chip->parent, "EIC level was changed.\n");
	state = post_state;
	goto retry;
	}

	sprd_eic_irq_unmask(data);
	}

	static int sprd_eic_match_chip_by_type(struct gpio_chip chip, void data)
	{
	enum sprd_eic_type type = (enum sprd_eic_type )data;

	return !strcmp(chip->label, sprd_eic_label_name[type]);
	}

	static void sprd_eic_handle_one_type(struct gpio_chip *chip)
	{
	struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
	u32 bank, n, girq;

	for (bank = 0; bank * SPRD_EIC_PER_BANK_NR < chip->ngpio; bank++) {
	void __iomem *base = sprd_eic_offset_base(sprd_eic, bank);
	unsigned long reg;

	switch (sprd_eic->type) {
	case SPRD_EIC_DEBOUNCE:
	reg = readl_relaxed(base + SPRD_EIC_DBNC_MIS) &
	SPRD_EIC_DATA_MASK;
	break;
	case SPRD_EIC_LATCH:
	reg = readl_relaxed(base + SPRD_EIC_LATCH_INTMSK) &
	SPRD_EIC_DATA_MASK;
	break;
	case SPRD_EIC_ASYNC:
	reg = readl_relaxed(base + SPRD_EIC_ASYNC_INTMSK) &
	SPRD_EIC_DATA_MASK;
	break;
	case SPRD_EIC_SYNC:
	reg = readl_relaxed(base + SPRD_EIC_SYNC_INTMSK) &
	SPRD_EIC_DATA_MASK;
	break;
	default:
	dev_err(chip->parent, "Unsupported EIC type.\n");
	return;
	}

	for_each_set_bit(n, &reg, SPRD_EIC_PER_BANK_NR) {
	u32 offset = bank * SPRD_EIC_PER_BANK_NR + n;

	girq = irq_find_mapping(chip->irq.domain, offset);

	generic_handle_irq(girq);
	sprd_eic_toggle_trigger(chip, girq, offset);
	}
	}
	}

	static void sprd_eic_irq_handler(struct irq_desc *desc)
	{
	struct irq_chip *ic = irq_desc_get_chip(desc);
	struct gpio_chip *chip;
	enum sprd_eic_type type;

	chained_irq_enter(ic, desc);

	/*
	* Since the digital-chip EIC 4 sub-modules (debounce, latch, async
	* and sync) share one same interrupt line, we should iterate each
	* EIC module to check if there are EIC interrupts were triggered.
	*/
	for (type = SPRD_EIC_DEBOUNCE; type < SPRD_EIC_MAX; type++) {
	chip = gpiochip_find(&type, sprd_eic_match_chip_by_type);
	if (!chip)
	continue;

	sprd_eic_handle_one_type(chip);
	}

	chained_irq_exit(ic, desc);
	}

	static const struct irq_chip sprd_eic_irq = {
	.name = "sprd-eic",
	.irq_ack = sprd_eic_irq_ack,
	.irq_mask = sprd_eic_irq_mask,
	.irq_unmask = sprd_eic_irq_unmask,
	.irq_set_type = sprd_eic_irq_set_type,
	.flags = IRQCHIP_SKIP_SET_WAKE \| IRQCHIP_IMMUTABLE,
	GPIOCHIP_IRQ_RESOURCE_HELPERS,
	};
	static int sprd_eic_probe(struct platform_device *pdev)
	{
	const struct sprd_eic_variant_data *pdata;
	struct gpio_irq_chip *irq;
	struct sprd_eic *sprd_eic;
	struct resource *res;
	int ret, i;

	pdata = of_device_get_match_data(&pdev->dev);
	if (!pdata) {
	dev_err(&pdev->dev, "No matching driver data found.\n");
	return -EINVAL;
	}

	sprd_eic = devm_kzalloc(&pdev->dev, sizeof(*sprd_eic), GFP_KERNEL);
	if (!sprd_eic)
	return -ENOMEM;

	spin_lock_init(&sprd_eic->lock);
	sprd_eic->type = pdata->type;

	sprd_eic->irq = platform_get_irq(pdev, 0);
	if (sprd_eic->irq < 0)
	return sprd_eic->irq;

	for (i = 0; i < SPRD_EIC_MAX_BANK; i++) {
	/*
	* We can have maximum 3 banks EICs, and each EIC has
	* its own base address. But some platform maybe only
	* have one bank EIC, thus base[1] and base[2] can be
	* optional.
	*/
	res = platform_get_resource(pdev, IORESOURCE_MEM, i);
	if (!res)
	break;

	sprd_eic->base[i] = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(sprd_eic->base[i]))
	return PTR_ERR(sprd_eic->base[i]);
	}

	sprd_eic->chip.label = sprd_eic_label_name[sprd_eic->type];
	sprd_eic->chip.ngpio = pdata->num_eics;
	sprd_eic->chip.base = -1;
	sprd_eic->chip.parent = &pdev->dev;
	sprd_eic->chip.direction_input = sprd_eic_direction_input;
	switch (sprd_eic->type) {
	case SPRD_EIC_DEBOUNCE:
	sprd_eic->chip.request = sprd_eic_request;
	sprd_eic->chip.free = sprd_eic_free;
	sprd_eic->chip.set_config = sprd_eic_set_config;
	sprd_eic->chip.set = sprd_eic_set;
	fallthrough;
	case SPRD_EIC_ASYNC:
	case SPRD_EIC_SYNC:
	sprd_eic->chip.get = sprd_eic_get;
	break;
	case SPRD_EIC_LATCH:
	default:
	break;
	}

	irq = &sprd_eic->chip.irq;
	gpio_irq_chip_set_chip(irq, &sprd_eic_irq);
	irq->handler = handle_bad_irq;
	irq->default_type = IRQ_TYPE_NONE;
	irq->parent_handler = sprd_eic_irq_handler;
	irq->parent_handler_data = sprd_eic;
	irq->num_parents = 1;
	irq->parents = &sprd_eic->irq;

	ret = devm_gpiochip_add_data(&pdev->dev, &sprd_eic->chip, sprd_eic);
	if (ret < 0) {
	dev_err(&pdev->dev, "Could not register gpiochip %d.\n", ret);
	return ret;
	}

	platform_set_drvdata(pdev, sprd_eic);
	return 0;
	}

	static const struct of_device_id sprd_eic_of_match[] = {
	{
	.compatible = "sprd,sc9860-eic-debounce",
	.data = &sc9860_eic_dbnc_data,
	},
	{
	.compatible = "sprd,sc9860-eic-latch",
	.data = &sc9860_eic_latch_data,
	},
	{
	.compatible = "sprd,sc9860-eic-async",
	.data = &sc9860_eic_async_data,
	},
	{
	.compatible = "sprd,sc9860-eic-sync",
	.data = &sc9860_eic_sync_data,
	},
	{
	/* end of list */
	}
	};
	MODULE_DEVICE_TABLE(of, sprd_eic_of_match);

	static struct platform_driver sprd_eic_driver = {
	.probe = sprd_eic_probe,
	.driver = {
	.name = "sprd-eic",
	.of_match_table = sprd_eic_of_match,
	},
	};

	module_platform_driver(sprd_eic_driver);

	MODULE_DESCRIPTION("Spreadtrum EIC driver");
	MODULE_LICENSE("GPL v2");