// SPDX-License-Identifier: GPL-2.0
/*
 * nvec_ps2: mouse driver for a NVIDIA compliant embedded controller
 *
 * Copyright (C) 2011 The AC100 Kernel Team <ac100@lists.launchpad.net>
 *
 * Authors:  Pierre-Hugues Husson <phhusson@free.fr>
 *           Ilya Petrov <ilya.muromec@gmail.com>
 *           Marc Dietrich <marvin24@gmx.de>
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/serio.h>
#include <linux/delay.h>
#include <linux/platform_device.h>

#include "nvec.h"

#define PACKET_SIZE     6

#define ENABLE_MOUSE    0xf4
#define DISABLE_MOUSE   0xf5
#define PSMOUSE_RST     0xff

enum ps2_subcmds {
        SEND_COMMAND = 1,
        RECEIVE_N,
        AUTO_RECEIVE_N,
        CANCEL_AUTO_RECEIVE,
};

struct nvec_ps2 {
        struct serio *ser_dev;
        struct notifier_block notifier;
        struct nvec_chip *nvec;
};

static struct nvec_ps2 ps2_dev;

static int ps2_startstreaming(struct serio *ser_dev)
{
        unsigned char buf[] = { NVEC_PS2, AUTO_RECEIVE_N, PACKET_SIZE };

        return nvec_write_async(ps2_dev.nvec, buf, sizeof(buf));
}

static void ps2_stopstreaming(struct serio *ser_dev)
{
        unsigned char buf[] = { NVEC_PS2, CANCEL_AUTO_RECEIVE };

        nvec_write_async(ps2_dev.nvec, buf, sizeof(buf));
}

static int nvec_ps2_notifier(struct notifier_block *nb,
                             unsigned long event_type, void *data)
{
        int i;
        unsigned char *msg = data;

        switch (event_type) {
        case NVEC_PS2_EVT:
                for (i = 0; i < msg[1]; i++)
                        serio_interrupt(ps2_dev.ser_dev, msg[2 + i], 0);
                return NOTIFY_STOP;

        case NVEC_PS2:
                if (msg[2] == 1) {
                        for (i = 0; i < (msg[1] - 2); i++)
                                serio_interrupt(ps2_dev.ser_dev, msg[i + 4], 0);
                }

                return NOTIFY_STOP;
        }

        return NOTIFY_DONE;
}

static int ps2_sendcommand(struct serio *ser_dev, unsigned char cmd)
{
        unsigned char buf[] = { NVEC_PS2, SEND_COMMAND, ENABLE_MOUSE, 1 };
        struct nvec_msg *msg;
        int ret;

        buf[2] = cmd & 0xff;

        dev_dbg(&ser_dev->dev, "Sending ps2 cmd %02x\n", cmd);

        ret = nvec_write_sync(ps2_dev.nvec, buf, sizeof(buf), &msg);
        if (ret < 0)
                return ret;

        nvec_ps2_notifier(NULL, NVEC_PS2, msg->data);

        nvec_msg_free(ps2_dev.nvec, msg);

        return 0;
}

static int nvec_mouse_probe(struct platform_device *pdev)
{
        struct nvec_chip *nvec = dev_get_drvdata(pdev->dev.parent);
        struct serio *ser_dev;

        ser_dev = kzalloc_obj(*ser_dev);
        if (!ser_dev)
                return -ENOMEM;

        ser_dev->id.type = SERIO_8042;
        ser_dev->write = ps2_sendcommand;
        ser_dev->start = ps2_startstreaming;
        ser_dev->stop = ps2_stopstreaming;

        strscpy(ser_dev->name, "nvec mouse", sizeof(ser_dev->name));
        strscpy(ser_dev->phys, "nvec", sizeof(ser_dev->phys));

        ps2_dev.ser_dev = ser_dev;
        ps2_dev.notifier.notifier_call = nvec_ps2_notifier;
        ps2_dev.nvec = nvec;
        nvec_register_notifier(nvec, &ps2_dev.notifier, 0);

        serio_register_port(ser_dev);

        return 0;
}

static void nvec_mouse_remove(struct platform_device *pdev)
{
        struct nvec_chip *nvec = dev_get_drvdata(pdev->dev.parent);

        ps2_sendcommand(ps2_dev.ser_dev, DISABLE_MOUSE);
        ps2_stopstreaming(ps2_dev.ser_dev);
        nvec_unregister_notifier(nvec, &ps2_dev.notifier);
        serio_unregister_port(ps2_dev.ser_dev);
}

#ifdef CONFIG_PM_SLEEP
static int nvec_mouse_suspend(struct device *dev)
{
        /* disable mouse */
        ps2_sendcommand(ps2_dev.ser_dev, DISABLE_MOUSE);

        /* send cancel autoreceive */
        ps2_stopstreaming(ps2_dev.ser_dev);

        return 0;
}

static int nvec_mouse_resume(struct device *dev)
{
        /* start streaming */
        ps2_startstreaming(ps2_dev.ser_dev);

        /* enable mouse */
        ps2_sendcommand(ps2_dev.ser_dev, ENABLE_MOUSE);

        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(nvec_mouse_pm_ops, nvec_mouse_suspend,
                         nvec_mouse_resume);

static struct platform_driver nvec_mouse_driver = {
        .probe  = nvec_mouse_probe,
        .remove = nvec_mouse_remove,
        .driver = {
                .name = "nvec-mouse",
                .pm = &nvec_mouse_pm_ops,
        },
};

module_platform_driver(nvec_mouse_driver);

MODULE_DESCRIPTION("NVEC mouse driver");
MODULE_AUTHOR("Marc Dietrich <marvin24@gmx.de>");
MODULE_ALIAS("platform:nvec-mouse");
MODULE_LICENSE("GPL");