// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 * h3600 atmel micro companion support, key subdevice
 * based on previous kernel 2.4 version
 * Author : Alessandro Gardich <gremlin@gremlin.it>
 * Author : Linus Walleij <linus.walleij@linaro.org>
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/input.h>
#include <linux/platform_device.h>
#include <linux/mfd/ipaq-micro.h>

struct ipaq_micro_keys {
        struct ipaq_micro *micro;
        struct input_dev *input;
        u16 *codes;
};

static const u16 micro_keycodes[] = {
        KEY_RECORD,             /* 1:  Record button                    */
        KEY_CALENDAR,           /* 2:  Calendar                         */
        KEY_ADDRESSBOOK,        /* 3:  Contacts (looks like Outlook)    */
        KEY_MAIL,               /* 4:  Envelope (Q on older iPAQs)      */
        KEY_HOMEPAGE,           /* 5:  Start (looks like swoopy arrow)  */
        KEY_UP,                 /* 6:  Up                               */
        KEY_RIGHT,              /* 7:  Right                            */
        KEY_LEFT,               /* 8:  Left                             */
        KEY_DOWN,               /* 9:  Down                             */
};

static void micro_key_receive(void *data, int len, unsigned char *msg)
{
        struct ipaq_micro_keys *keys = data;
        int key, down;

        down = 0x80 & msg[0];
        key  = 0x7f & msg[0];

        if (key < ARRAY_SIZE(micro_keycodes)) {
                input_report_key(keys->input, keys->codes[key], down);
                input_sync(keys->input);
        }
}

static void micro_key_start(struct ipaq_micro_keys *keys)
{
        guard(spinlock)(&keys->micro->lock);

        keys->micro->key = micro_key_receive;
        keys->micro->key_data = keys;
}

static void micro_key_stop(struct ipaq_micro_keys *keys)
{
        guard(spinlock)(&keys->micro->lock);

        keys->micro->key = NULL;
        keys->micro->key_data = NULL;
}

static int micro_key_open(struct input_dev *input)
{
        struct ipaq_micro_keys *keys = input_get_drvdata(input);

        micro_key_start(keys);

        return 0;
}

static void micro_key_close(struct input_dev *input)
{
        struct ipaq_micro_keys *keys = input_get_drvdata(input);

        micro_key_stop(keys);
}

static int micro_key_probe(struct platform_device *pdev)
{
        struct ipaq_micro_keys *keys;
        int error;
        int i;

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

        keys->micro = dev_get_drvdata(pdev->dev.parent);

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

        keys->input->keycodesize = sizeof(micro_keycodes[0]);
        keys->input->keycodemax = ARRAY_SIZE(micro_keycodes);
        keys->codes = devm_kmemdup_array(&pdev->dev, micro_keycodes, keys->input->keycodemax,
                                         keys->input->keycodesize, GFP_KERNEL);
        if (!keys->codes)
                return -ENOMEM;

        keys->input->keycode = keys->codes;

        __set_bit(EV_KEY, keys->input->evbit);
        for (i = 0; i < ARRAY_SIZE(micro_keycodes); i++)
                __set_bit(micro_keycodes[i], keys->input->keybit);

        keys->input->name = "h3600 micro keys";
        keys->input->open = micro_key_open;
        keys->input->close = micro_key_close;
        input_set_drvdata(keys->input, keys);

        error = input_register_device(keys->input);
        if (error)
                return error;

        platform_set_drvdata(pdev, keys);
        return 0;
}

static int micro_key_suspend(struct device *dev)
{
        struct ipaq_micro_keys *keys = dev_get_drvdata(dev);

        micro_key_stop(keys);

        return 0;
}

static int micro_key_resume(struct device *dev)
{
        struct ipaq_micro_keys *keys = dev_get_drvdata(dev);
        struct input_dev *input = keys->input;

        guard(mutex)(&input->mutex);

        if (input_device_enabled(input))
                micro_key_start(keys);

        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(micro_key_dev_pm_ops,
                                micro_key_suspend, micro_key_resume);

static struct platform_driver micro_key_device_driver = {
        .driver = {
                .name    = "ipaq-micro-keys",
                .pm     = pm_sleep_ptr(&micro_key_dev_pm_ops),
        },
        .probe   = micro_key_probe,
};
module_platform_driver(micro_key_device_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("driver for iPAQ Atmel micro keys");
MODULE_ALIAS("platform:ipaq-micro-keys");