// SPDX-License-Identifier: GPL-2.0-only
/*
 * linux/drivers/input/keyboard/pxa27x_keypad.c
 *
 * Driver for the pxa27x matrix keyboard controller.
 *
 * Created:     Feb 22, 2007
 * Author:      Rodolfo Giometti <giometti@linux.it>
 *
 * Based on a previous implementations by Kevin O'Connor
 * <kevin_at_koconnor.net> and Alex Osborne <bobofdoom@gmail.com> and
 * on some suggestions by Nicolas Pitre <nico@fluxnic.net>.
 */

#include <linux/bits.h>
#include <linux/bitfield.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/io.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/input/matrix_keypad.h>
#include <linux/slab.h>
#include <linux/of.h>

/*
 * Keypad Controller registers
 */
#define KPC             0x0000 /* Keypad Control register */
#define KPDK            0x0008 /* Keypad Direct Key register */
#define KPREC           0x0010 /* Keypad Rotary Encoder register */
#define KPMK            0x0018 /* Keypad Matrix Key register */
#define KPAS            0x0020 /* Keypad Automatic Scan register */

/* Keypad Automatic Scan Multiple Key Presser register 0-3 */
#define KPASMKP0        0x0028
#define KPASMKP1        0x0030
#define KPASMKP2        0x0038
#define KPASMKP3        0x0040
#define KPKDI           0x0048

/* bit definitions */
#define KPC_MKRN_MASK   GENMASK(28, 26)
#define KPC_MKCN_MASK   GENMASK(25, 23)
#define KPC_DKN_MASK    GENMASK(8, 6)
#define KPC_MKRN(n)     FIELD_PREP(KPC_MKRN_MASK, (n) - 1)
#define KPC_MKCN(n)     FIELD_PREP(KPC_MKCN_MASK, (n) - 1)
#define KPC_DKN(n)      FIELD_PREP(KPC_DKN_MASK, (n) - 1)

#define KPC_AS          BIT(30)  /* Automatic Scan bit */
#define KPC_ASACT       BIT(29)  /* Automatic Scan on Activity */
#define KPC_MI          BIT(22)  /* Matrix interrupt bit */
#define KPC_IMKP        BIT(21)  /* Ignore Multiple Key Press */

#define KPC_MS(n)       BIT(13 + (n))   /* Matrix scan line 'n' */
#define KPC_MS_ALL      GENMASK(20, 13)

#define KPC_ME          BIT(12)  /* Matrix Keypad Enable */
#define KPC_MIE         BIT(11)  /* Matrix Interrupt Enable */
#define KPC_DK_DEB_SEL  BIT(9)   /* Direct Keypad Debounce Select */
#define KPC_DI          BIT(5)   /* Direct key interrupt bit */
#define KPC_RE_ZERO_DEB BIT(4)   /* Rotary Encoder Zero Debounce */
#define KPC_REE1        BIT(3)   /* Rotary Encoder1 Enable */
#define KPC_REE0        BIT(2)   /* Rotary Encoder0 Enable */
#define KPC_DE          BIT(1)   /* Direct Keypad Enable */
#define KPC_DIE         BIT(0)   /* Direct Keypad interrupt Enable */

#define KPDK_DKP        BIT(31)
#define KPDK_DK_MASK    GENMASK(7, 0)
#define KPDK_DK(n)      FIELD_GET(KPDK_DK_MASK, n)

#define KPREC_OF1       BIT(31)
#define KPREC_UF1       BIT(30)
#define KPREC_OF0       BIT(15)
#define KPREC_UF0       BIT(14)

#define KPREC_RECOUNT0_MASK     GENMASK(7, 0)
#define KPREC_RECOUNT1_MASK     GENMASK(23, 16)
#define KPREC_RECOUNT0(n)       FIELD_GET(KPREC_RECOUNT0_MASK, n)
#define KPREC_RECOUNT1(n)       FIELD_GET(KPREC_RECOUNT1_MASK, n)

#define KPMK_MKP        BIT(31)
#define KPAS_SO         BIT(31)
#define KPASMKPx_SO     BIT(31)

#define KPAS_MUKP_MASK  GENMASK(30, 26)
#define KPAS_RP_MASK    GENMASK(7, 4)
#define KPAS_CP_MASK    GENMASK(3, 0)
#define KPAS_MUKP(n)    FIELD_GET(KPAS_MUKP_MASK, n)
#define KPAS_RP(n)      FIELD_GET(KPAS_RP_MASK, n)
#define KPAS_CP(n)      FIELD_GET(KPAS_CP_MASK, n)

#define KPASMKP_MKC_MASK        GENMASK(7, 0)

#define keypad_readl(off)       __raw_readl(keypad->mmio_base + (off))
#define keypad_writel(off, v)   __raw_writel((v), keypad->mmio_base + (off))

#define MAX_MATRIX_KEY_ROWS     8
#define MAX_MATRIX_KEY_COLS     8
#define MAX_DIRECT_KEY_NUM      8
#define MAX_ROTARY_ENCODERS     2

#define MAX_MATRIX_KEY_NUM      (MAX_MATRIX_KEY_ROWS * MAX_MATRIX_KEY_COLS)
#define MAX_KEYPAD_KEYS         (MAX_MATRIX_KEY_NUM + MAX_DIRECT_KEY_NUM)

struct pxa27x_keypad_rotary {
        unsigned short *key_codes;
        int rel_code;
        bool enabled;
};

struct pxa27x_keypad {
        struct clk *clk;
        struct input_dev *input_dev;
        void __iomem *mmio_base;

        int irq;

        unsigned int matrix_key_rows;
        unsigned int matrix_key_cols;
        unsigned int row_shift;

        unsigned int direct_key_num;
        unsigned int direct_key_mask;
        bool direct_key_low_active;

        /* key debounce interval */
        unsigned int debounce_interval;

        unsigned short keycodes[MAX_KEYPAD_KEYS];

        /* state row bits of each column scan */
        u32 matrix_key_state[MAX_MATRIX_KEY_COLS];
        u32 direct_key_state;

        struct pxa27x_keypad_rotary rotary[MAX_ROTARY_ENCODERS];
};

static int pxa27x_keypad_matrix_key_parse(struct pxa27x_keypad *keypad)
{
        struct input_dev *input_dev = keypad->input_dev;
        struct device *dev = input_dev->dev.parent;
        int error;

        error = matrix_keypad_parse_properties(dev, &keypad->matrix_key_rows,
                                               &keypad->matrix_key_cols);
        if (error)
                return error;

        if (keypad->matrix_key_rows > MAX_MATRIX_KEY_ROWS ||
            keypad->matrix_key_cols > MAX_MATRIX_KEY_COLS) {
                dev_err(dev, "rows or cols exceeds maximum value\n");
                return -EINVAL;
        }

        keypad->row_shift = get_count_order(keypad->matrix_key_cols);

        error = matrix_keypad_build_keymap(NULL, NULL,
                                           keypad->matrix_key_rows,
                                           keypad->matrix_key_cols,
                                           keypad->keycodes, input_dev);
        if (error)
                return error;

        return 0;
}

static int pxa27x_keypad_direct_key_parse(struct pxa27x_keypad *keypad)
{
        struct input_dev *input_dev = keypad->input_dev;
        struct device *dev = input_dev->dev.parent;
        unsigned short code;
        int count;
        int i;
        int error;

        error = device_property_read_u32(dev, "marvell,direct-key-count",
                                         &keypad->direct_key_num);
        if (error) {
                /*
                 * If do not have marvel,direct-key-count defined,
                 * it means direct key is not supported.
                 */
                return error == -EINVAL ? 0 : error;
        }

        error = device_property_read_u32(dev, "marvell,direct-key-mask",
                                         &keypad->direct_key_mask);
        if (error) {
                if (error != -EINVAL)
                        return error;

                /*
                 * If marvell,direct-key-mask is not defined, driver will use
                 * a default value based on number of direct keys set up.
                 * The default value is calculated in pxa27x_keypad_config().
                 */
                keypad->direct_key_mask = 0;
        }

        keypad->direct_key_low_active =
                device_property_read_bool(dev, "marvell,direct-key-low-active");

        count = device_property_count_u16(dev, "marvell,direct-key-map");
        if (count <= 0 || count > MAX_DIRECT_KEY_NUM)
                return -EINVAL;

        error = device_property_read_u16_array(dev, "marvell,direct-key-map",
                                               &keypad->keycodes[MAX_MATRIX_KEY_NUM],
                                               count);

        for (i = 0; i < count; i++) {
                code = keypad->keycodes[MAX_MATRIX_KEY_NUM + i];
                __set_bit(code, input_dev->keybit);
        }

        return 0;
}

static int pxa27x_keypad_rotary_parse(struct pxa27x_keypad *keypad)
{
        static const char * const rotaryname[] = { "marvell,rotary0", "marvell,rotary1" };
        struct input_dev *input_dev = keypad->input_dev;
        struct device *dev = input_dev->dev.parent;
        struct pxa27x_keypad_rotary *encoder;
        unsigned int code;
        int i;
        int error;

        error = device_property_read_u32(dev, "marvell,rotary-rel-key", &code);
        if (!error) {
                for (i = 0; i < MAX_ROTARY_ENCODERS; i++, code >>= 16) {
                        encoder = &keypad->rotary[i];
                        encoder->enabled = true;
                        encoder->rel_code = code & 0xffff;
                        input_set_capability(input_dev, EV_REL, encoder->rel_code);
                }

                return 0;
        }

        for (i = 0; i < MAX_ROTARY_ENCODERS; i++) {
                encoder = &keypad->rotary[i];

                /*
                 * If the prop is not set, it means keypad does not need
                 * initialize the rotaryX.
                 */
                if (!device_property_present(dev, rotaryname[i]))
                        continue;

                error = device_property_read_u32(dev, rotaryname[i], &code);
                if (error)
                        return error;

                /*
                 * Not all up/down key code are valid.
                 * Now we depends on direct-rel-code.
                 */
                if (!(code & 0xffff) || !(code >> 16))
                        return -EINVAL;

                encoder->enabled = true;
                encoder->rel_code = -1;
                encoder->key_codes = &keypad->keycodes[MAX_MATRIX_KEY_NUM + i * 2];
                encoder->key_codes[0] = code & 0xffff;
                encoder->key_codes[1] = code >> 16;

                input_set_capability(input_dev, EV_KEY, encoder->key_codes[0]);
                input_set_capability(input_dev, EV_KEY, encoder->key_codes[1]);
        }

        return 0;
}

static int pxa27x_keypad_parse_properties(struct pxa27x_keypad *keypad)
{
        struct input_dev *input_dev = keypad->input_dev;
        struct device *dev = input_dev->dev.parent;
        int error;

        error = pxa27x_keypad_matrix_key_parse(keypad);
        if (error) {
                dev_err(dev, "failed to parse matrix key\n");
                return error;
        }

        error = pxa27x_keypad_direct_key_parse(keypad);
        if (error) {
                dev_err(dev, "failed to parse direct key\n");
                return error;
        }

        error = pxa27x_keypad_rotary_parse(keypad);
        if (error) {
                dev_err(dev, "failed to parse rotary key\n");
                return error;
        }

        error = device_property_read_u32(dev, "marvell,debounce-interval",
                                         &keypad->debounce_interval);
        if (error) {
                dev_err(dev, "failed to parse debounce-interval\n");
                return error;
        }

        /*
         * The keycodes may not only includes matrix key but also the direct
         * key or rotary key.
         */
        input_dev->keycodemax = ARRAY_SIZE(keypad->keycodes);

        return 0;
}

static void pxa27x_keypad_scan_matrix(struct pxa27x_keypad *keypad)
{
        struct input_dev *input_dev = keypad->input_dev;
        int row, col, num_keys_pressed = 0;
        u32 new_state[MAX_MATRIX_KEY_COLS];
        u32 kpas = keypad_readl(KPAS);

        num_keys_pressed = KPAS_MUKP(kpas);

        memset(new_state, 0, sizeof(new_state));

        if (num_keys_pressed == 0)
                goto scan;

        if (num_keys_pressed == 1) {
                col = KPAS_CP(kpas);
                row = KPAS_RP(kpas);

                /* if invalid row/col, treat as no key pressed */
                if (col >= keypad->matrix_key_cols ||
                    row >= keypad->matrix_key_rows)
                        goto scan;

                new_state[col] = BIT(row);
                goto scan;
        }

        if (num_keys_pressed > 1) {
                u32 kpasmkp0 = keypad_readl(KPASMKP0);
                u32 kpasmkp1 = keypad_readl(KPASMKP1);
                u32 kpasmkp2 = keypad_readl(KPASMKP2);
                u32 kpasmkp3 = keypad_readl(KPASMKP3);

                new_state[0] = kpasmkp0 & KPASMKP_MKC_MASK;
                new_state[1] = (kpasmkp0 >> 16) & KPASMKP_MKC_MASK;
                new_state[2] = kpasmkp1 & KPASMKP_MKC_MASK;
                new_state[3] = (kpasmkp1 >> 16) & KPASMKP_MKC_MASK;
                new_state[4] = kpasmkp2 & KPASMKP_MKC_MASK;
                new_state[5] = (kpasmkp2 >> 16) & KPASMKP_MKC_MASK;
                new_state[6] = kpasmkp3 & KPASMKP_MKC_MASK;
                new_state[7] = (kpasmkp3 >> 16) & KPASMKP_MKC_MASK;
        }
scan:
        for (col = 0; col < keypad->matrix_key_cols; col++) {
                u32 bits_changed;
                int code;

                bits_changed = keypad->matrix_key_state[col] ^ new_state[col];
                if (bits_changed == 0)
                        continue;

                for (row = 0; row < keypad->matrix_key_rows; row++) {
                        if ((bits_changed & BIT(row)) == 0)
                                continue;

                        code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);

                        input_event(input_dev, EV_MSC, MSC_SCAN, code);
                        input_report_key(input_dev, keypad->keycodes[code],
                                         new_state[col] & BIT(row));
                }
        }
        input_sync(input_dev);
        memcpy(keypad->matrix_key_state, new_state, sizeof(new_state));
}

#define DEFAULT_KPREC   (0x007f007f)

static inline int rotary_delta(u32 kprec)
{
        if (kprec & KPREC_OF0)
                return (kprec & 0xff) + 0x7f;
        else if (kprec & KPREC_UF0)
                return (kprec & 0xff) - 0x7f - 0xff;
        else
                return (kprec & 0xff) - 0x7f;
}

static void report_rotary_event(struct pxa27x_keypad *keypad, int r, int delta)
{
        struct pxa27x_keypad_rotary *encoder = &keypad->rotary[r];
        struct input_dev *dev = keypad->input_dev;

        if (!encoder->enabled || delta == 0)
                return;

        if (encoder->rel_code == -1) {
                int idx = delta > 0 ? 0 : 1;
                int code = MAX_MATRIX_KEY_NUM + 2 * r + idx;
                unsigned char keycode = encoder->key_codes[idx];

                /* simulate a press-n-release */
                input_event(dev, EV_MSC, MSC_SCAN, code);
                input_report_key(dev, keycode, 1);
                input_sync(dev);
                input_event(dev, EV_MSC, MSC_SCAN, code);
                input_report_key(dev, keycode, 0);
                input_sync(dev);
        } else {
                input_report_rel(dev, encoder->rel_code, delta);
                input_sync(dev);
        }
}

static void pxa27x_keypad_scan_rotary(struct pxa27x_keypad *keypad)
{
        u32 kprec;
        int i;

        /* read and reset to default count value */
        kprec = keypad_readl(KPREC);
        keypad_writel(KPREC, DEFAULT_KPREC);

        for (i = 0; i < MAX_ROTARY_ENCODERS; i++) {
                report_rotary_event(keypad, 0, rotary_delta(kprec));
                kprec >>= 16;
        }
}

static void pxa27x_keypad_scan_direct(struct pxa27x_keypad *keypad)
{
        struct input_dev *input_dev = keypad->input_dev;
        unsigned int new_state;
        u32 kpdk, bits_changed;
        int i;

        kpdk = keypad_readl(KPDK);

        if (keypad->rotary[0].enabled || keypad->rotary[1].enabled)
                pxa27x_keypad_scan_rotary(keypad);

        /*
         * The KPDR_DK only output the key pin level, so it relates to board,
         * and low level may be active.
         */
        if (keypad->direct_key_low_active)
                new_state = ~KPDK_DK(kpdk) & keypad->direct_key_mask;
        else
                new_state = KPDK_DK(kpdk) & keypad->direct_key_mask;

        bits_changed = keypad->direct_key_state ^ new_state;

        if (bits_changed == 0)
                return;

        for (i = 0; i < keypad->direct_key_num; i++) {
                if (bits_changed & BIT(i)) {
                        int code = MAX_MATRIX_KEY_NUM + i;

                        input_event(input_dev, EV_MSC, MSC_SCAN, code);
                        input_report_key(input_dev, keypad->keycodes[code],
                                         new_state & BIT(i));
                }
        }
        input_sync(input_dev);
        keypad->direct_key_state = new_state;
}

static irqreturn_t pxa27x_keypad_irq_handler(int irq, void *dev_id)
{
        struct pxa27x_keypad *keypad = dev_id;
        unsigned long kpc = keypad_readl(KPC);

        if (kpc & KPC_DI)
                pxa27x_keypad_scan_direct(keypad);

        if (kpc & KPC_MI)
                pxa27x_keypad_scan_matrix(keypad);

        return IRQ_HANDLED;
}

static void pxa27x_keypad_config(struct pxa27x_keypad *keypad)
{
        unsigned int mask = 0, direct_key_num = 0;
        unsigned long kpc = 0;

        /* clear pending interrupt bit */
        keypad_readl(KPC);

        /* enable matrix keys with automatic scan */
        if (keypad->matrix_key_rows && keypad->matrix_key_cols) {
                kpc |= KPC_ASACT | KPC_MIE | KPC_ME | KPC_MS_ALL;
                kpc |= KPC_MKRN(keypad->matrix_key_rows) |
                       KPC_MKCN(keypad->matrix_key_cols);
        }

        /* enable rotary key, debounce interval same as direct keys */
        if (keypad->rotary[0].enabled) {
                mask |= 0x03;
                direct_key_num = 2;
                kpc |= KPC_REE0;
        }

        if (keypad->rotary[1].enabled) {
                mask |= 0x0c;
                direct_key_num = 4;
                kpc |= KPC_REE1;
        }

        if (keypad->direct_key_num > direct_key_num)
                direct_key_num = keypad->direct_key_num;

        /*
         * Direct keys usage may not start from KP_DKIN0, check the platfrom
         * mask data to config the specific.
         */
        if (!keypad->direct_key_mask)
                keypad->direct_key_mask = GENMASK(direct_key_num - 1, 0) & ~mask;

        /* enable direct key */
        if (direct_key_num)
                kpc |= KPC_DE | KPC_DIE | KPC_DKN(direct_key_num);

        keypad_writel(KPC, kpc | KPC_RE_ZERO_DEB);
        keypad_writel(KPREC, DEFAULT_KPREC);
        keypad_writel(KPKDI, keypad->debounce_interval);
}

static int pxa27x_keypad_open(struct input_dev *dev)
{
        struct pxa27x_keypad *keypad = input_get_drvdata(dev);
        int ret;
        /* Enable unit clock */
        ret = clk_prepare_enable(keypad->clk);
        if (ret)
                return ret;

        pxa27x_keypad_config(keypad);

        return 0;
}

static void pxa27x_keypad_close(struct input_dev *dev)
{
        struct pxa27x_keypad *keypad = input_get_drvdata(dev);

        /* Disable clock unit */
        clk_disable_unprepare(keypad->clk);
}

static int pxa27x_keypad_suspend(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct pxa27x_keypad *keypad = platform_get_drvdata(pdev);

        /*
         * If the keypad is used a wake up source, clock can not be disabled.
         * Or it can not detect the key pressing.
         */
        if (device_may_wakeup(&pdev->dev))
                enable_irq_wake(keypad->irq);
        else
                clk_disable_unprepare(keypad->clk);

        return 0;
}

static int pxa27x_keypad_resume(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct pxa27x_keypad *keypad = platform_get_drvdata(pdev);
        struct input_dev *input_dev = keypad->input_dev;
        int error;

        /*
         * If the keypad is used as wake up source, the clock is not turned
         * off. So do not need configure it again.
         */
        if (device_may_wakeup(&pdev->dev)) {
                disable_irq_wake(keypad->irq);
        } else {
                guard(mutex)(&input_dev->mutex);

                if (input_device_enabled(input_dev)) {
                        /* Enable unit clock */
                        error = clk_prepare_enable(keypad->clk);
                        if (error)
                                return error;

                        pxa27x_keypad_config(keypad);
                }
        }

        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(pxa27x_keypad_pm_ops,
                                pxa27x_keypad_suspend, pxa27x_keypad_resume);

static int pxa27x_keypad_probe(struct platform_device *pdev)
{
        struct pxa27x_keypad *keypad;
        struct input_dev *input_dev;
        int irq;
        int error;

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

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

        input_dev = devm_input_allocate_device(&pdev->dev);
        if (!input_dev)
                return -ENOMEM;

        keypad->input_dev = input_dev;
        keypad->irq = irq;

        keypad->mmio_base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(keypad->mmio_base))
                return PTR_ERR(keypad->mmio_base);

        keypad->clk = devm_clk_get(&pdev->dev, NULL);
        if (IS_ERR(keypad->clk)) {
                dev_err(&pdev->dev, "failed to get keypad clock\n");
                return PTR_ERR(keypad->clk);
        }

        input_dev->name = pdev->name;
        input_dev->id.bustype = BUS_HOST;
        input_dev->open = pxa27x_keypad_open;
        input_dev->close = pxa27x_keypad_close;
        input_dev->dev.parent = &pdev->dev;

        input_dev->keycode = keypad->keycodes;
        input_dev->keycodesize = sizeof(keypad->keycodes[0]);
        input_dev->keycodemax = ARRAY_SIZE(keypad->keycodes);

        input_set_drvdata(input_dev, keypad);

        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
        input_set_capability(input_dev, EV_MSC, MSC_SCAN);

        error = pxa27x_keypad_parse_properties(keypad);
        if (error) {
                dev_err(&pdev->dev, "failed to parse keypad properties\n");
                return error;
        }

        error = devm_request_irq(&pdev->dev, irq, pxa27x_keypad_irq_handler,
                                 0, pdev->name, keypad);
        if (error) {
                dev_err(&pdev->dev, "failed to request IRQ\n");
                return error;
        }

        /* Register the input device */
        error = input_register_device(input_dev);
        if (error) {
                dev_err(&pdev->dev, "failed to register input device\n");
                return error;
        }

        platform_set_drvdata(pdev, keypad);
        device_init_wakeup(&pdev->dev, 1);

        return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id pxa27x_keypad_dt_match[] = {
        { .compatible = "marvell,pxa27x-keypad" },
        {},
};
MODULE_DEVICE_TABLE(of, pxa27x_keypad_dt_match);
#endif

static struct platform_driver pxa27x_keypad_driver = {
        .probe          = pxa27x_keypad_probe,
        .driver         = {
                .name   = "pxa27x-keypad",
                .of_match_table = of_match_ptr(pxa27x_keypad_dt_match),
                .pm     = pm_sleep_ptr(&pxa27x_keypad_pm_ops),
        },
};
module_platform_driver(pxa27x_keypad_driver);

MODULE_DESCRIPTION("PXA27x Keypad Controller Driver");
MODULE_LICENSE("GPL");
/* work with hotplug and coldplug */
MODULE_ALIAS("platform:pxa27x-keypad");