// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * linux/drivers/input/keyboard/omap-keypad.c
 *
 * OMAP Keypad Driver
 *
 * Copyright (C) 2003 Nokia Corporation
 * Written by Timo Teräs <ext-timo.teras@nokia.com>
 *
 * Added support for H2 & H3 Keypad
 * Copyright (C) 2004 Texas Instruments
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/types.h>
#include <linux/input.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/platform_data/gpio-omap.h>
#include <linux/platform_data/keypad-omap.h>
#include <linux/soc/ti/omap1-io.h>

#undef NEW_BOARD_LEARNING_MODE

static void omap_kp_tasklet(unsigned long);
static void omap_kp_timer(struct timer_list *);

static unsigned char keypad_state[8];
static DEFINE_MUTEX(kp_enable_mutex);
static int kp_enable = 1;
static int kp_cur_group = -1;

struct omap_kp {
        struct input_dev *input;
        struct timer_list timer;
        int irq;
        unsigned int rows;
        unsigned int cols;
        unsigned long delay;
        unsigned int debounce;
        unsigned short keymap[];
};

static DECLARE_TASKLET_DISABLED_OLD(kp_tasklet, omap_kp_tasklet);

static irqreturn_t omap_kp_interrupt(int irq, void *dev_id)
{
        /* disable keyboard interrupt and schedule for handling */
        omap_writew(1, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBD_MASKIT);

        tasklet_schedule(&kp_tasklet);

        return IRQ_HANDLED;
}

static void omap_kp_timer(struct timer_list *unused)
{
        tasklet_schedule(&kp_tasklet);
}

static void omap_kp_scan_keypad(struct omap_kp *omap_kp, unsigned char *state)
{
        int col = 0;

        /* disable keyboard interrupt and schedule for handling */
        omap_writew(1, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBD_MASKIT);

        /* read the keypad status */
        omap_writew(0xff, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBC);
        for (col = 0; col < omap_kp->cols; col++) {
                omap_writew(~(1 << col) & 0xff,
                            OMAP1_MPUIO_BASE + OMAP_MPUIO_KBC);

                udelay(omap_kp->delay);

                state[col] = ~omap_readw(OMAP1_MPUIO_BASE +
                                         OMAP_MPUIO_KBR_LATCH) & 0xff;
        }
        omap_writew(0x00, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBC);
        udelay(2);
}

static void omap_kp_tasklet(unsigned long data)
{
        struct omap_kp *omap_kp_data = (struct omap_kp *) data;
        unsigned short *keycodes = omap_kp_data->input->keycode;
        unsigned int row_shift = get_count_order(omap_kp_data->cols);
        unsigned char new_state[8], changed, key_down = 0;
        int col, row;

        /* check for any changes */
        omap_kp_scan_keypad(omap_kp_data, new_state);

        /* check for changes and print those */
        for (col = 0; col < omap_kp_data->cols; col++) {
                changed = new_state[col] ^ keypad_state[col];
                key_down |= new_state[col];
                if (changed == 0)
                        continue;

                for (row = 0; row < omap_kp_data->rows; row++) {
                        int key;
                        if (!(changed & (1 << row)))
                                continue;
#ifdef NEW_BOARD_LEARNING_MODE
                        printk(KERN_INFO "omap-keypad: key %d-%d %s\n", col,
                               row, (new_state[col] & (1 << row)) ?
                               "pressed" : "released");
#else
                        key = keycodes[MATRIX_SCAN_CODE(row, col, row_shift)];

                        if (!(kp_cur_group == (key & GROUP_MASK) ||
                              kp_cur_group == -1))
                                continue;

                        kp_cur_group = key & GROUP_MASK;
                        input_report_key(omap_kp_data->input, key & ~GROUP_MASK,
                                         new_state[col] & (1 << row));
#endif
                }
        }
        input_sync(omap_kp_data->input);
        memcpy(keypad_state, new_state, sizeof(keypad_state));

        if (key_down) {
                /* some key is pressed - keep irq disabled and use timer
                 * to poll the keypad */
                mod_timer(&omap_kp_data->timer, jiffies + HZ / 20);
        } else {
                /* enable interrupts */
                omap_writew(0, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBD_MASKIT);
                kp_cur_group = -1;
        }
}

static ssize_t omap_kp_enable_show(struct device *dev,
                                   struct device_attribute *attr, char *buf)
{
        return sprintf(buf, "%u\n", kp_enable);
}

static ssize_t omap_kp_enable_store(struct device *dev, struct device_attribute *attr,
                                    const char *buf, size_t count)
{
        struct omap_kp *omap_kp = dev_get_drvdata(dev);
        int state;

        if (sscanf(buf, "%u", &state) != 1)
                return -EINVAL;

        if ((state != 1) && (state != 0))
                return -EINVAL;

        scoped_guard(mutex, &kp_enable_mutex) {
                if (state != kp_enable) {
                        if (state)
                                enable_irq(omap_kp->irq);
                        else
                                disable_irq(omap_kp->irq);
                        kp_enable = state;
                }
        }

        return strnlen(buf, count);
}

static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, omap_kp_enable_show, omap_kp_enable_store);

static struct attribute *omap_kp_attrs[] = {
        &dev_attr_enable.attr,
        NULL
};
ATTRIBUTE_GROUPS(omap_kp);

static int omap_kp_probe(struct platform_device *pdev)
{
        struct omap_kp *omap_kp;
        struct input_dev *input_dev;
        struct omap_kp_platform_data *pdata = dev_get_platdata(&pdev->dev);
        int ret;
        unsigned int row_shift, keycodemax;

        if (!pdata->rows || !pdata->cols || !pdata->keymap_data) {
                printk(KERN_ERR "No rows, cols or keymap_data from pdata\n");
                return -EINVAL;
        }

        row_shift = get_count_order(pdata->cols);
        keycodemax = pdata->rows << row_shift;

        omap_kp = kzalloc_flex(*omap_kp, keymap, keycodemax);
        input_dev = input_allocate_device();
        if (!omap_kp || !input_dev) {
                kfree(omap_kp);
                input_free_device(input_dev);
                return -ENOMEM;
        }

        platform_set_drvdata(pdev, omap_kp);

        omap_kp->input = input_dev;

        /* Disable the interrupt for the MPUIO keyboard */
        omap_writew(1, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBD_MASKIT);

        if (pdata->delay)
                omap_kp->delay = pdata->delay;

        omap_kp->rows = pdata->rows;
        omap_kp->cols = pdata->cols;

        timer_setup(&omap_kp->timer, omap_kp_timer, 0);

        /* get the irq and init timer*/
        kp_tasklet.data = (unsigned long) omap_kp;
        tasklet_enable(&kp_tasklet);

        /* setup input device */
        input_dev->name = "omap-keypad";
        input_dev->phys = "omap-keypad/input0";
        input_dev->dev.parent = &pdev->dev;

        input_dev->id.bustype = BUS_HOST;
        input_dev->id.vendor = 0x0001;
        input_dev->id.product = 0x0001;
        input_dev->id.version = 0x0100;

        if (pdata->rep)
                __set_bit(EV_REP, input_dev->evbit);

        ret = matrix_keypad_build_keymap(pdata->keymap_data, NULL,
                                         pdata->rows, pdata->cols,
                                         omap_kp->keymap, input_dev);
        if (ret < 0)
                goto err2;

        ret = input_register_device(omap_kp->input);
        if (ret < 0) {
                printk(KERN_ERR "Unable to register omap-keypad input device\n");
                goto err2;
        }

        if (pdata->dbounce)
                omap_writew(0xff, OMAP1_MPUIO_BASE + OMAP_MPUIO_GPIO_DEBOUNCING);

        /* scan current status and enable interrupt */
        omap_kp_scan_keypad(omap_kp, keypad_state);
        omap_kp->irq = platform_get_irq(pdev, 0);
        if (omap_kp->irq >= 0) {
                if (request_irq(omap_kp->irq, omap_kp_interrupt, 0,
                                "omap-keypad", omap_kp) < 0)
                        goto err3;
        }
        omap_writew(0, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBD_MASKIT);

        return 0;

err3:
        input_unregister_device(omap_kp->input);
        input_dev = NULL;
err2:
        kfree(omap_kp);
        input_free_device(input_dev);

        return -EINVAL;
}

static void omap_kp_remove(struct platform_device *pdev)
{
        struct omap_kp *omap_kp = platform_get_drvdata(pdev);

        /* disable keypad interrupt handling */
        tasklet_disable(&kp_tasklet);
        omap_writew(1, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBD_MASKIT);
        free_irq(omap_kp->irq, omap_kp);

        timer_shutdown_sync(&omap_kp->timer);
        tasklet_kill(&kp_tasklet);

        /* unregister everything */
        input_unregister_device(omap_kp->input);

        kfree(omap_kp);
}

static struct platform_driver omap_kp_driver = {
        .probe          = omap_kp_probe,
        .remove         = omap_kp_remove,
        .driver         = {
                .name   = "omap-keypad",
                .dev_groups = omap_kp_groups,
        },
};
module_platform_driver(omap_kp_driver);

MODULE_AUTHOR("Timo Teräs");
MODULE_DESCRIPTION("OMAP Keypad Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:omap-keypad");