// SPDX-License-Identifier: GPL-2.0-only
/*
 * Dynapro serial touchscreen driver
 *
 * Copyright (c) 2009 Tias Guns
 * Based on the inexio driver (c) Vojtech Pavlik and Dan Streetman and
 * Richard Lemon
 */


/*
 * 2009/09/19 Tias Guns <tias@ulyssis.org>
 *   Copied inexio.c and edited for Dynapro protocol (from retired Xorg module)
 */

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/serio.h>

#define DRIVER_DESC     "Dynapro serial touchscreen driver"

MODULE_AUTHOR("Tias Guns <tias@ulyssis.org>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

/*
 * Definitions & global arrays.
 */

#define DYNAPRO_FORMAT_TOUCH_BIT 0x40
#define DYNAPRO_FORMAT_LENGTH 3
#define DYNAPRO_RESPONSE_BEGIN_BYTE 0x80

#define DYNAPRO_MIN_XC 0
#define DYNAPRO_MAX_XC 0x3ff
#define DYNAPRO_MIN_YC 0
#define DYNAPRO_MAX_YC 0x3ff

#define DYNAPRO_GET_XC(data) (data[1] | ((data[0] & 0x38) << 4))
#define DYNAPRO_GET_YC(data) (data[2] | ((data[0] & 0x07) << 7))
#define DYNAPRO_GET_TOUCHED(data) (DYNAPRO_FORMAT_TOUCH_BIT & data[0])

/*
 * Per-touchscreen data.
 */

struct dynapro {
        struct input_dev *dev;
        struct serio *serio;
        int idx;
        unsigned char data[DYNAPRO_FORMAT_LENGTH];
        char phys[32];
};

static void dynapro_process_data(struct dynapro *pdynapro)
{
        struct input_dev *dev = pdynapro->dev;

        if (DYNAPRO_FORMAT_LENGTH == ++pdynapro->idx) {
                input_report_abs(dev, ABS_X, DYNAPRO_GET_XC(pdynapro->data));
                input_report_abs(dev, ABS_Y, DYNAPRO_GET_YC(pdynapro->data));
                input_report_key(dev, BTN_TOUCH,
                                 DYNAPRO_GET_TOUCHED(pdynapro->data));
                input_sync(dev);

                pdynapro->idx = 0;
        }
}

static irqreturn_t dynapro_interrupt(struct serio *serio,
                unsigned char data, unsigned int flags)
{
        struct dynapro *pdynapro = serio_get_drvdata(serio);

        pdynapro->data[pdynapro->idx] = data;

        if (DYNAPRO_RESPONSE_BEGIN_BYTE & pdynapro->data[0])
                dynapro_process_data(pdynapro);
        else
                dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n",
                        pdynapro->data[0]);

        return IRQ_HANDLED;
}

static void dynapro_disconnect(struct serio *serio)
{
        struct dynapro *pdynapro = serio_get_drvdata(serio);

        input_get_device(pdynapro->dev);
        input_unregister_device(pdynapro->dev);
        serio_close(serio);
        serio_set_drvdata(serio, NULL);
        input_put_device(pdynapro->dev);
        kfree(pdynapro);
}

/*
 * dynapro_connect() is the routine that is called when someone adds a
 * new serio device that supports dynapro protocol and registers it as
 * an input device. This is usually accomplished using inputattach.
 */

static int dynapro_connect(struct serio *serio, struct serio_driver *drv)
{
        struct dynapro *pdynapro;
        struct input_dev *input_dev;
        int err;

        pdynapro = kzalloc_obj(*pdynapro);
        input_dev = input_allocate_device();
        if (!pdynapro || !input_dev) {
                err = -ENOMEM;
                goto fail1;
        }

        pdynapro->serio = serio;
        pdynapro->dev = input_dev;
        scnprintf(pdynapro->phys, sizeof(pdynapro->phys),
                  "%s/input0", serio->phys);

        input_dev->name = "Dynapro Serial TouchScreen";
        input_dev->phys = pdynapro->phys;
        input_dev->id.bustype = BUS_RS232;
        input_dev->id.vendor = SERIO_DYNAPRO;
        input_dev->id.product = 0;
        input_dev->id.version = 0x0001;
        input_dev->dev.parent = &serio->dev;
        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
        input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
        input_set_abs_params(pdynapro->dev, ABS_X,
                             DYNAPRO_MIN_XC, DYNAPRO_MAX_XC, 0, 0);
        input_set_abs_params(pdynapro->dev, ABS_Y,
                             DYNAPRO_MIN_YC, DYNAPRO_MAX_YC, 0, 0);

        serio_set_drvdata(serio, pdynapro);

        err = serio_open(serio, drv);
        if (err)
                goto fail2;

        err = input_register_device(pdynapro->dev);
        if (err)
                goto fail3;

        return 0;

 fail3: serio_close(serio);
 fail2: serio_set_drvdata(serio, NULL);
 fail1: input_free_device(input_dev);
        kfree(pdynapro);
        return err;
}

/*
 * The serio driver structure.
 */

static const struct serio_device_id dynapro_serio_ids[] = {
        {
                .type   = SERIO_RS232,
                .proto  = SERIO_DYNAPRO,
                .id     = SERIO_ANY,
                .extra  = SERIO_ANY,
        },
        { 0 }
};

MODULE_DEVICE_TABLE(serio, dynapro_serio_ids);

static struct serio_driver dynapro_drv = {
        .driver         = {
                .name   = "dynapro",
        },
        .description    = DRIVER_DESC,
        .id_table       = dynapro_serio_ids,
        .interrupt      = dynapro_interrupt,
        .connect        = dynapro_connect,
        .disconnect     = dynapro_disconnect,
};

module_serio_driver(dynapro_drv);