// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * File: drivers/input/keyboard/adp5588_keys.c
 * Description:  keypad driver for ADP5588 and ADP5587
 *               I2C QWERTY Keypad and IO Expander
 * Bugs: Enter bugs at http://blackfin.uclinux.org/
 *
 * Copyright (C) 2008-2010 Analog Devices Inc.
 */

#include <linux/bits.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/input/matrix_keypad.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/ktime.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/pinctrl/pinconf-generic.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/timekeeping.h>

#define DEV_ID 0x00             /* Device ID */
#define CFG 0x01                /* Configuration Register1 */
#define INT_STAT 0x02           /* Interrupt Status Register */
#define KEY_LCK_EC_STAT 0x03    /* Key Lock and Event Counter Register */
#define KEY_EVENTA 0x04         /* Key Event Register A */
#define KEY_EVENTB 0x05         /* Key Event Register B */
#define KEY_EVENTC 0x06         /* Key Event Register C */
#define KEY_EVENTD 0x07         /* Key Event Register D */
#define KEY_EVENTE 0x08         /* Key Event Register E */
#define KEY_EVENTF 0x09         /* Key Event Register F */
#define KEY_EVENTG 0x0A         /* Key Event Register G */
#define KEY_EVENTH 0x0B         /* Key Event Register H */
#define KEY_EVENTI 0x0C         /* Key Event Register I */
#define KEY_EVENTJ 0x0D         /* Key Event Register J */
#define KP_LCK_TMR 0x0E         /* Keypad Lock1 to Lock2 Timer */
#define UNLOCK1 0x0F            /* Unlock Key1 */
#define UNLOCK2 0x10            /* Unlock Key2 */
#define GPIO_INT_STAT1 0x11     /* GPIO Interrupt Status */
#define GPIO_INT_STAT2 0x12     /* GPIO Interrupt Status */
#define GPIO_INT_STAT3 0x13     /* GPIO Interrupt Status */
#define GPIO_DAT_STAT1 0x14     /* GPIO Data Status, Read twice to clear */
#define GPIO_DAT_STAT2 0x15     /* GPIO Data Status, Read twice to clear */
#define GPIO_DAT_STAT3 0x16     /* GPIO Data Status, Read twice to clear */
#define GPIO_DAT_OUT1 0x17      /* GPIO DATA OUT */
#define GPIO_DAT_OUT2 0x18      /* GPIO DATA OUT */
#define GPIO_DAT_OUT3 0x19      /* GPIO DATA OUT */
#define GPIO_INT_EN1 0x1A       /* GPIO Interrupt Enable */
#define GPIO_INT_EN2 0x1B       /* GPIO Interrupt Enable */
#define GPIO_INT_EN3 0x1C       /* GPIO Interrupt Enable */
#define KP_GPIO1 0x1D           /* Keypad or GPIO Selection */
#define KP_GPIO2 0x1E           /* Keypad or GPIO Selection */
#define KP_GPIO3 0x1F           /* Keypad or GPIO Selection */
#define GPI_EM1 0x20            /* GPI Event Mode 1 */
#define GPI_EM2 0x21            /* GPI Event Mode 2 */
#define GPI_EM3 0x22            /* GPI Event Mode 3 */
#define GPIO_DIR1 0x23          /* GPIO Data Direction */
#define GPIO_DIR2 0x24          /* GPIO Data Direction */
#define GPIO_DIR3 0x25          /* GPIO Data Direction */
#define GPIO_INT_LVL1 0x26      /* GPIO Edge/Level Detect */
#define GPIO_INT_LVL2 0x27      /* GPIO Edge/Level Detect */
#define GPIO_INT_LVL3 0x28      /* GPIO Edge/Level Detect */
#define DEBOUNCE_DIS1 0x29      /* Debounce Disable */
#define DEBOUNCE_DIS2 0x2A      /* Debounce Disable */
#define DEBOUNCE_DIS3 0x2B      /* Debounce Disable */
#define GPIO_PULL1 0x2C         /* GPIO Pull Disable */
#define GPIO_PULL2 0x2D         /* GPIO Pull Disable */
#define GPIO_PULL3 0x2E         /* GPIO Pull Disable */
#define CMP_CFG_STAT 0x30       /* Comparator Configuration and Status Register */
#define CMP_CONFG_SENS1 0x31    /* Sensor1 Comparator Configuration Register */
#define CMP_CONFG_SENS2 0x32    /* L2 Light Sensor Reference Level, Output Falling for Sensor 1 */
#define CMP1_LVL2_TRIP 0x33     /* L2 Light Sensor Hysteresis (Active when Output Rising) for Sensor 1 */
#define CMP1_LVL2_HYS 0x34      /* L3 Light Sensor Reference Level, Output Falling For Sensor 1 */
#define CMP1_LVL3_TRIP 0x35     /* L3 Light Sensor Hysteresis (Active when Output Rising) For Sensor 1 */
#define CMP1_LVL3_HYS 0x36      /* Sensor 2 Comparator Configuration Register */
#define CMP2_LVL2_TRIP 0x37     /* L2 Light Sensor Reference Level, Output Falling for Sensor 2 */
#define CMP2_LVL2_HYS 0x38      /* L2 Light Sensor Hysteresis (Active when Output Rising) for Sensor 2 */
#define CMP2_LVL3_TRIP 0x39     /* L3 Light Sensor Reference Level, Output Falling For Sensor 2 */
#define CMP2_LVL3_HYS 0x3A      /* L3 Light Sensor Hysteresis (Active when Output Rising) For Sensor 2 */
#define CMP1_ADC_DAT_R1 0x3B    /* Comparator 1 ADC data Register1 */
#define CMP1_ADC_DAT_R2 0x3C    /* Comparator 1 ADC data Register2 */
#define CMP2_ADC_DAT_R1 0x3D    /* Comparator 2 ADC data Register1 */
#define CMP2_ADC_DAT_R2 0x3E    /* Comparator 2 ADC data Register2 */

#define ADP5588_DEVICE_ID_MASK  0xF

 /* Configuration Register1 */
#define ADP5588_AUTO_INC        BIT(7)
#define ADP5588_GPIEM_CFG       BIT(6)
#define ADP5588_OVR_FLOW_M      BIT(5)
#define ADP5588_INT_CFG         BIT(4)
#define ADP5588_OVR_FLOW_IEN    BIT(3)
#define ADP5588_K_LCK_IM        BIT(2)
#define ADP5588_GPI_IEN         BIT(1)
#define ADP5588_KE_IEN          BIT(0)

/* Interrupt Status Register */
#define ADP5588_CMP2_INT        BIT(5)
#define ADP5588_CMP1_INT        BIT(4)
#define ADP5588_OVR_FLOW_INT    BIT(3)
#define ADP5588_K_LCK_INT       BIT(2)
#define ADP5588_GPI_INT         BIT(1)
#define ADP5588_KE_INT          BIT(0)

/* Key Lock and Event Counter Register */
#define ADP5588_K_LCK_EN        BIT(6)
#define ADP5588_LCK21           0x30
#define ADP5588_KEC             GENMASK(3, 0)

#define ADP5588_MAXGPIO         18
#define ADP5588_BANK(offs)      ((offs) >> 3)
#define ADP5588_BIT(offs)       (1u << ((offs) & 0x7))

/* Put one of these structures in i2c_board_info platform_data */

/*
 * 128 so it fits matrix-keymap maximum number of keys when the full
 * 10cols * 8rows are used.
 */
#define ADP5588_KEYMAPSIZE 128

#define GPI_PIN_ROW0 97
#define GPI_PIN_ROW1 98
#define GPI_PIN_ROW2 99
#define GPI_PIN_ROW3 100
#define GPI_PIN_ROW4 101
#define GPI_PIN_ROW5 102
#define GPI_PIN_ROW6 103
#define GPI_PIN_ROW7 104
#define GPI_PIN_COL0 105
#define GPI_PIN_COL1 106
#define GPI_PIN_COL2 107
#define GPI_PIN_COL3 108
#define GPI_PIN_COL4 109
#define GPI_PIN_COL5 110
#define GPI_PIN_COL6 111
#define GPI_PIN_COL7 112
#define GPI_PIN_COL8 113
#define GPI_PIN_COL9 114

#define GPI_PIN_ROW_BASE GPI_PIN_ROW0
#define GPI_PIN_ROW_END GPI_PIN_ROW7
#define GPI_PIN_COL_BASE GPI_PIN_COL0
#define GPI_PIN_COL_END GPI_PIN_COL9

#define GPI_PIN_BASE GPI_PIN_ROW_BASE
#define GPI_PIN_END GPI_PIN_COL_END

#define ADP5588_ROWS_MAX (GPI_PIN_ROW7 - GPI_PIN_ROW0 + 1)
#define ADP5588_COLS_MAX (GPI_PIN_COL9 - GPI_PIN_COL0 + 1)

#define ADP5588_GPIMAPSIZE_MAX (GPI_PIN_END - GPI_PIN_BASE + 1)

/* Key Event Register xy */
#define KEY_EV_PRESSED          BIT(7)
#define KEY_EV_MASK             GENMASK(6, 0)

#define KP_SEL(x)               (BIT(x) - 1)    /* 2^x-1 */

#define KEYP_MAX_EVENT          10

/*
 * Early pre 4.0 Silicon required to delay readout by at least 25ms,
 * since the Event Counter Register updated 25ms after the interrupt
 * asserted.
 */
#define WA_DELAYED_READOUT_REVID(rev)           ((rev) < 4)
#define WA_DELAYED_READOUT_TIME                 25

#define ADP5588_INVALID_HWIRQ   (~0UL)

struct adp5588_kpad {
        struct i2c_client *client;
        struct input_dev *input;
        ktime_t irq_time;
        unsigned long delay;
        u32 row_shift;
        u32 rows;
        u32 cols;
        u32 unlock_keys[2];
        int nkeys_unlock;
        bool gpio_only;
        unsigned short keycode[ADP5588_KEYMAPSIZE];
        unsigned char gpiomap[ADP5588_MAXGPIO];
        struct gpio_chip gc;
        struct mutex gpio_lock; /* Protect cached dir, dat_out */
        u8 dat_out[3];
        u8 dir[3];
        u8 int_en[3];
        u8 irq_mask[3];
        u8 pull_dis[3];
};

static int adp5588_read(struct i2c_client *client, u8 reg)
{
        int ret = i2c_smbus_read_byte_data(client, reg);

        if (ret < 0)
                dev_err(&client->dev, "Read Error\n");

        return ret;
}

static int adp5588_write(struct i2c_client *client, u8 reg, u8 val)
{
        return i2c_smbus_write_byte_data(client, reg, val);
}

static int adp5588_gpio_get_value(struct gpio_chip *chip, unsigned int off)
{
        struct adp5588_kpad *kpad = gpiochip_get_data(chip);
        unsigned int bank = ADP5588_BANK(kpad->gpiomap[off]);
        unsigned int bit = ADP5588_BIT(kpad->gpiomap[off]);
        int val;

        guard(mutex)(&kpad->gpio_lock);

        if (kpad->dir[bank] & bit)
                val = kpad->dat_out[bank];
        else
                val = adp5588_read(kpad->client, GPIO_DAT_STAT1 + bank);

        return !!(val & bit);
}

static int adp5588_gpio_set_value(struct gpio_chip *chip, unsigned int off,
                                  int val)
{
        struct adp5588_kpad *kpad = gpiochip_get_data(chip);
        unsigned int bank = ADP5588_BANK(kpad->gpiomap[off]);
        unsigned int bit = ADP5588_BIT(kpad->gpiomap[off]);

        guard(mutex)(&kpad->gpio_lock);

        if (val)
                kpad->dat_out[bank] |= bit;
        else
                kpad->dat_out[bank] &= ~bit;

        return adp5588_write(kpad->client, GPIO_DAT_OUT1 + bank,
                             kpad->dat_out[bank]);
}

static int adp5588_gpio_set_config(struct gpio_chip *chip,  unsigned int off,
                                   unsigned long config)
{
        struct adp5588_kpad *kpad = gpiochip_get_data(chip);
        unsigned int bank = ADP5588_BANK(kpad->gpiomap[off]);
        unsigned int bit = ADP5588_BIT(kpad->gpiomap[off]);
        bool pull_disable;

        switch (pinconf_to_config_param(config)) {
        case PIN_CONFIG_BIAS_PULL_UP:
                pull_disable = false;
                break;
        case PIN_CONFIG_BIAS_DISABLE:
                pull_disable = true;
                break;
        default:
                return -ENOTSUPP;
        }

        guard(mutex)(&kpad->gpio_lock);

        if (pull_disable)
                kpad->pull_dis[bank] |= bit;
        else
                kpad->pull_dis[bank] &= bit;

        return adp5588_write(kpad->client, GPIO_PULL1 + bank,
                             kpad->pull_dis[bank]);
}

static int adp5588_gpio_direction_input(struct gpio_chip *chip, unsigned int off)
{
        struct adp5588_kpad *kpad = gpiochip_get_data(chip);
        unsigned int bank = ADP5588_BANK(kpad->gpiomap[off]);
        unsigned int bit = ADP5588_BIT(kpad->gpiomap[off]);

        guard(mutex)(&kpad->gpio_lock);

        kpad->dir[bank] &= ~bit;
        return adp5588_write(kpad->client, GPIO_DIR1 + bank, kpad->dir[bank]);
}

static int adp5588_gpio_direction_output(struct gpio_chip *chip,
                                         unsigned int off, int val)
{
        struct adp5588_kpad *kpad = gpiochip_get_data(chip);
        unsigned int bank = ADP5588_BANK(kpad->gpiomap[off]);
        unsigned int bit = ADP5588_BIT(kpad->gpiomap[off]);
        int error;

        guard(mutex)(&kpad->gpio_lock);

        kpad->dir[bank] |= bit;

        if (val)
                kpad->dat_out[bank] |= bit;
        else
                kpad->dat_out[bank] &= ~bit;

        error = adp5588_write(kpad->client, GPIO_DAT_OUT1 + bank,
                              kpad->dat_out[bank]);
        if (error)
                return error;

        error = adp5588_write(kpad->client, GPIO_DIR1 + bank, kpad->dir[bank]);
        if (error)
                return error;

        return 0;
}

static int adp5588_build_gpiomap(struct adp5588_kpad *kpad)
{
        bool pin_used[ADP5588_MAXGPIO];
        int n_unused = 0;
        int i;

        memset(pin_used, 0, sizeof(pin_used));

        for (i = 0; i < kpad->rows; i++)
                pin_used[i] = true;

        for (i = 0; i < kpad->cols; i++)
                pin_used[i + GPI_PIN_COL_BASE - GPI_PIN_BASE] = true;

        for (i = 0; i < ADP5588_MAXGPIO; i++)
                if (!pin_used[i])
                        kpad->gpiomap[n_unused++] = i;

        return n_unused;
}

static void adp5588_irq_bus_lock(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct adp5588_kpad *kpad = gpiochip_get_data(gc);

        mutex_lock(&kpad->gpio_lock);
}

static void adp5588_irq_bus_sync_unlock(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct adp5588_kpad *kpad = gpiochip_get_data(gc);
        int i;

        for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
                if (kpad->int_en[i] ^ kpad->irq_mask[i]) {
                        kpad->int_en[i] = kpad->irq_mask[i];
                        adp5588_write(kpad->client, GPI_EM1 + i, kpad->int_en[i]);
                }
        }

        mutex_unlock(&kpad->gpio_lock);
}

static void adp5588_irq_mask(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct adp5588_kpad *kpad = gpiochip_get_data(gc);
        irq_hw_number_t hwirq = irqd_to_hwirq(d);
        unsigned long real_irq = kpad->gpiomap[hwirq];

        kpad->irq_mask[ADP5588_BANK(real_irq)] &= ~ADP5588_BIT(real_irq);
        gpiochip_disable_irq(gc, hwirq);
}

static void adp5588_irq_unmask(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct adp5588_kpad *kpad = gpiochip_get_data(gc);
        irq_hw_number_t hwirq = irqd_to_hwirq(d);
        unsigned long real_irq = kpad->gpiomap[hwirq];

        gpiochip_enable_irq(gc, hwirq);
        kpad->irq_mask[ADP5588_BANK(real_irq)] |= ADP5588_BIT(real_irq);
}

static int adp5588_irq_set_type(struct irq_data *d, unsigned int type)
{
        if (!(type & IRQ_TYPE_EDGE_BOTH))
                return -EINVAL;

        irq_set_handler_locked(d, handle_edge_irq);

        return 0;
}

static const struct irq_chip adp5588_irq_chip = {
        .name = "adp5588",
        .irq_mask = adp5588_irq_mask,
        .irq_unmask = adp5588_irq_unmask,
        .irq_bus_lock = adp5588_irq_bus_lock,
        .irq_bus_sync_unlock = adp5588_irq_bus_sync_unlock,
        .irq_set_type = adp5588_irq_set_type,
        .flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_IMMUTABLE,
        GPIOCHIP_IRQ_RESOURCE_HELPERS,
};

static int adp5588_gpio_add(struct adp5588_kpad *kpad)
{
        struct device *dev = &kpad->client->dev;
        struct gpio_irq_chip *girq;
        int i, error;

        kpad->gc.ngpio = adp5588_build_gpiomap(kpad);
        if (kpad->gc.ngpio == 0) {
                dev_info(dev, "No unused gpios left to export\n");
                return 0;
        }

        kpad->gc.parent = &kpad->client->dev;
        kpad->gc.direction_input = adp5588_gpio_direction_input;
        kpad->gc.direction_output = adp5588_gpio_direction_output;
        kpad->gc.get = adp5588_gpio_get_value;
        kpad->gc.set = adp5588_gpio_set_value;
        kpad->gc.set_config = adp5588_gpio_set_config;
        kpad->gc.can_sleep = 1;

        kpad->gc.base = -1;
        kpad->gc.label = kpad->client->name;
        kpad->gc.owner = THIS_MODULE;

        if (device_property_present(dev, "interrupt-controller")) {
                if (!kpad->client->irq) {
                        dev_err(dev, "Unable to serve as interrupt controller without interrupt");
                        return -EINVAL;
                }

                girq = &kpad->gc.irq;
                gpio_irq_chip_set_chip(girq, &adp5588_irq_chip);
                girq->handler = handle_bad_irq;
                girq->threaded = true;
        }

        mutex_init(&kpad->gpio_lock);

        error = devm_gpiochip_add_data(dev, &kpad->gc, kpad);
        if (error) {
                dev_err(dev, "gpiochip_add failed: %d\n", error);
                return error;
        }

        for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
                kpad->dat_out[i] = adp5588_read(kpad->client,
                                                GPIO_DAT_OUT1 + i);
                kpad->dir[i] = adp5588_read(kpad->client, GPIO_DIR1 + i);
                kpad->pull_dis[i] = adp5588_read(kpad->client, GPIO_PULL1 + i);
        }

        return 0;
}

static unsigned long adp5588_gpiomap_get_hwirq(struct device *dev,
                                               const u8 *map, unsigned int gpio,
                                               unsigned int ngpios)
{
        unsigned int hwirq;

        for (hwirq = 0; hwirq < ngpios; hwirq++)
                if (map[hwirq] == gpio)
                        return hwirq;

        /* should never happen */
        dev_warn_ratelimited(dev, "could not find the hwirq for gpio(%u)\n", gpio);

        return ADP5588_INVALID_HWIRQ;
}

static void adp5588_gpio_irq_handle(struct adp5588_kpad *kpad, int key_val,
                                    int key_press)
{
        unsigned int irq, gpio = key_val - GPI_PIN_BASE, irq_type;
        struct i2c_client *client = kpad->client;
        struct irq_data *irqd;
        unsigned long hwirq;

        hwirq = adp5588_gpiomap_get_hwirq(&client->dev, kpad->gpiomap,
                                          gpio, kpad->gc.ngpio);
        if (hwirq == ADP5588_INVALID_HWIRQ) {
                dev_err(&client->dev, "Could not get hwirq for key(%u)\n", key_val);
                return;
        }

        irq = irq_find_mapping(kpad->gc.irq.domain, hwirq);
        if (!irq)
                return;

        irqd = irq_get_irq_data(irq);
        if (!irqd) {
                dev_err(&client->dev, "Could not get irq(%u) data\n", irq);
                return;
        }

        irq_type = irqd_get_trigger_type(irqd);

        /*
         * Default is active low which means key_press is asserted on
         * the falling edge.
         */
        if ((irq_type & IRQ_TYPE_EDGE_RISING && !key_press) ||
            (irq_type & IRQ_TYPE_EDGE_FALLING && key_press))
                handle_nested_irq(irq);
}

static void adp5588_report_events(struct adp5588_kpad *kpad, int ev_cnt)
{
        int i;

        for (i = 0; i < ev_cnt; i++) {
                int key = adp5588_read(kpad->client, KEY_EVENTA + i);
                int key_val = key & KEY_EV_MASK;
                int key_press = key & KEY_EV_PRESSED;

                if (key_val >= GPI_PIN_BASE && key_val <= GPI_PIN_END) {
                        /* gpio line used as IRQ source */
                        adp5588_gpio_irq_handle(kpad, key_val, key_press);
                } else {
                        int row = (key_val - 1) / ADP5588_COLS_MAX;
                        int col =  (key_val - 1) % ADP5588_COLS_MAX;
                        int code = MATRIX_SCAN_CODE(row, col, kpad->row_shift);

                        dev_dbg_ratelimited(&kpad->client->dev,
                                            "report key(%d) r(%d) c(%d) code(%d)\n",
                                            key_val, row, col, kpad->keycode[code]);

                        input_report_key(kpad->input,
                                         kpad->keycode[code], key_press);
                }
        }
}

static irqreturn_t adp5588_hard_irq(int irq, void *handle)
{
        struct adp5588_kpad *kpad = handle;

        kpad->irq_time = ktime_get();

        return IRQ_WAKE_THREAD;
}

static irqreturn_t adp5588_thread_irq(int irq, void *handle)
{
        struct adp5588_kpad *kpad = handle;
        struct i2c_client *client = kpad->client;
        ktime_t target_time, now;
        unsigned long delay;
        int status, ev_cnt;

        /*
         * Readout needs to wait for at least 25ms after the notification
         * for REVID < 4.
         */
        if (kpad->delay) {
                target_time = ktime_add_ms(kpad->irq_time, kpad->delay);
                now = ktime_get();
                if (ktime_before(now, target_time)) {
                        delay = ktime_to_us(ktime_sub(target_time, now));
                        usleep_range(delay, delay + 1000);
                }
        }

        status = adp5588_read(client, INT_STAT);

        if (status & ADP5588_OVR_FLOW_INT)      /* Unlikely and should never happen */
                dev_err(&client->dev, "Event Overflow Error\n");

        if (status & ADP5588_KE_INT) {
                ev_cnt = adp5588_read(client, KEY_LCK_EC_STAT) & ADP5588_KEC;
                if (ev_cnt) {
                        adp5588_report_events(kpad, ev_cnt);
                        input_sync(kpad->input);
                }
        }

        adp5588_write(client, INT_STAT, status); /* Status is W1C */

        return IRQ_HANDLED;
}

static int adp5588_setup(struct adp5588_kpad *kpad)
{
        struct i2c_client *client = kpad->client;
        int i, ret;

        ret = adp5588_write(client, KP_GPIO1, KP_SEL(kpad->rows));
        if (ret)
                return ret;

        ret = adp5588_write(client, KP_GPIO2, KP_SEL(kpad->cols) & 0xFF);
        if (ret)
                return ret;

        ret = adp5588_write(client, KP_GPIO3, KP_SEL(kpad->cols) >> 8);
        if (ret)
                return ret;

        for (i = 0; i < kpad->nkeys_unlock; i++) {
                ret = adp5588_write(client, UNLOCK1 + i, kpad->unlock_keys[i]);
                if (ret)
                        return ret;
        }

        if (kpad->nkeys_unlock) {
                ret = adp5588_write(client, KEY_LCK_EC_STAT, ADP5588_K_LCK_EN);
                if (ret)
                        return ret;
        }

        for (i = 0; i < KEYP_MAX_EVENT; i++) {
                ret = adp5588_read(client, KEY_EVENTA);
                if (ret < 0)
                        return ret;
        }

        ret = adp5588_write(client, INT_STAT,
                            ADP5588_CMP2_INT | ADP5588_CMP1_INT |
                            ADP5588_OVR_FLOW_INT | ADP5588_K_LCK_INT |
                            ADP5588_GPI_INT | ADP5588_KE_INT); /* Status is W1C */
        if (ret)
                return ret;

        return adp5588_write(client, CFG, ADP5588_INT_CFG |
                             ADP5588_OVR_FLOW_IEN | ADP5588_KE_IEN);
}

static int adp5588_fw_parse(struct adp5588_kpad *kpad)
{
        struct i2c_client *client = kpad->client;
        int ret, i;

        /*
         * Check if the device is to be operated purely in GPIO mode. To do
         * so, check that no keypad rows or columns have been specified,
         * since all GPINS should be configured as GPIO.
         */
        if (!device_property_present(&client->dev, "keypad,num-rows") &&
            !device_property_present(&client->dev, "keypad,num-columns")) {
                /* If purely GPIO, skip keypad setup */
                kpad->gpio_only = true;
                return 0;
        }

        ret = matrix_keypad_parse_properties(&client->dev, &kpad->rows,
                                             &kpad->cols);
        if (ret)
                return ret;

        if (kpad->rows > ADP5588_ROWS_MAX || kpad->cols > ADP5588_COLS_MAX) {
                dev_err(&client->dev, "Invalid nr of rows(%u) or cols(%u)\n",
                        kpad->rows, kpad->cols);
                return -EINVAL;
        }

        ret = matrix_keypad_build_keymap(NULL, NULL, kpad->rows, kpad->cols,
                                         kpad->keycode, kpad->input);
        if (ret)
                return ret;

        kpad->row_shift = get_count_order(kpad->cols);

        if (device_property_read_bool(&client->dev, "autorepeat"))
                __set_bit(EV_REP, kpad->input->evbit);

        kpad->nkeys_unlock = device_property_count_u32(&client->dev,
                                                       "adi,unlock-keys");
        if (kpad->nkeys_unlock <= 0) {
                /* so that we don't end up enabling key lock */
                kpad->nkeys_unlock = 0;
                return 0;
        }

        if (kpad->nkeys_unlock > ARRAY_SIZE(kpad->unlock_keys)) {
                dev_err(&client->dev, "number of unlock keys(%d) > (%zu)\n",
                        kpad->nkeys_unlock, ARRAY_SIZE(kpad->unlock_keys));
                return -EINVAL;
        }

        ret = device_property_read_u32_array(&client->dev, "adi,unlock-keys",
                                             kpad->unlock_keys,
                                             kpad->nkeys_unlock);
        if (ret)
                return ret;

        for (i = 0; i < kpad->nkeys_unlock; i++) {
                /*
                 * Even though it should be possible (as stated in the datasheet)
                 * to use GPIs (which are part of the keys event) as unlock keys,
                 * it was not working at all and was leading to overflow events
                 * at some point. Hence, for now, let's just allow keys which are
                 * part of keypad matrix to be used and if a reliable way of
                 * using GPIs is found, this condition can be removed/lightened.
                 */
                if (kpad->unlock_keys[i] >= kpad->cols * kpad->rows) {
                        dev_err(&client->dev, "Invalid unlock key(%d)\n",
                                kpad->unlock_keys[i]);
                        return -EINVAL;
                }

                /*
                 * Firmware properties keys start from 0 but on the device they
                 * start from 1.
                 */
                kpad->unlock_keys[i] += 1;
        }

        return 0;
}

static int adp5588_probe(struct i2c_client *client)
{
        struct adp5588_kpad *kpad;
        struct input_dev *input;
        struct gpio_desc *gpio;
        unsigned int revid;
        int ret;
        int error;

        if (!i2c_check_functionality(client->adapter,
                                     I2C_FUNC_SMBUS_BYTE_DATA)) {
                dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
                return -EIO;
        }

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

        input = devm_input_allocate_device(&client->dev);
        if (!input)
                return -ENOMEM;

        kpad->client = client;
        kpad->input = input;

        error = adp5588_fw_parse(kpad);
        if (error)
                return error;

        error = devm_regulator_get_enable(&client->dev, "vcc");
        if (error)
                return error;

        gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH);
        if (IS_ERR(gpio))
                return PTR_ERR(gpio);

        if (gpio) {
                fsleep(30);
                gpiod_set_value_cansleep(gpio, 0);
                fsleep(60);
        }

        ret = adp5588_read(client, DEV_ID);
        if (ret < 0)
                return ret;

        revid = ret & ADP5588_DEVICE_ID_MASK;
        if (WA_DELAYED_READOUT_REVID(revid))
                kpad->delay = msecs_to_jiffies(WA_DELAYED_READOUT_TIME);

        input->name = client->name;
        input->phys = "adp5588-keys/input0";

        input_set_drvdata(input, kpad);

        input->id.bustype = BUS_I2C;
        input->id.vendor = 0x0001;
        input->id.product = 0x0001;
        input->id.version = revid;

        error = input_register_device(input);
        if (error) {
                dev_err(&client->dev, "unable to register input device: %d\n",
                        error);
                return error;
        }

        error = adp5588_setup(kpad);
        if (error)
                return error;

        error = adp5588_gpio_add(kpad);
        if (error)
                return error;

        if (client->irq) {
                error = devm_request_threaded_irq(&client->dev, client->irq,
                                                  adp5588_hard_irq, adp5588_thread_irq,
                                                  IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
                                                  client->dev.driver->name, kpad);
                if (error) {
                        dev_err(&client->dev, "failed to request irq %d: %d\n",
                                client->irq, error);
                        return error;
                }
        }

        dev_info(&client->dev, "Rev.%d controller\n", revid);
        return 0;
}

static void adp5588_remove(struct i2c_client *client)
{
        adp5588_write(client, CFG, 0);

        /* all resources will be freed by devm */
}

static int adp5588_suspend(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);

        if (client->irq)
                disable_irq(client->irq);

        return 0;
}

static int adp5588_resume(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);

        if (client->irq)
                enable_irq(client->irq);

        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(adp5588_dev_pm_ops, adp5588_suspend, adp5588_resume);

static const struct i2c_device_id adp5588_id[] = {
        { "adp5588-keys" },
        { "adp5587-keys" },
        { }
};
MODULE_DEVICE_TABLE(i2c, adp5588_id);

static const struct of_device_id adp5588_of_match[] = {
        { .compatible = "adi,adp5588" },
        { .compatible = "adi,adp5587" },
        {}
};
MODULE_DEVICE_TABLE(of, adp5588_of_match);

static struct i2c_driver adp5588_driver = {
        .driver = {
                .name = KBUILD_MODNAME,
                .of_match_table = adp5588_of_match,
                .pm   = pm_sleep_ptr(&adp5588_dev_pm_ops),
        },
        .probe    = adp5588_probe,
        .remove   = adp5588_remove,
        .id_table = adp5588_id,
};

module_i2c_driver(adp5588_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("ADP5588/87 Keypad driver");