// SPDX-License-Identifier: GPL-2.0-only
/*
 * drivers/input/touchscreen/jornada720_ts.c
 *
 * Copyright (C) 2007 Kristoffer Ericson <Kristoffer.Ericson@gmail.com>
 *
 *  Copyright (C) 2006 Filip Zyzniewski <filip.zyzniewski@tefnet.pl>
 *  based on HP Jornada 56x touchscreen driver by Alex Lange <chicken@handhelds.org>
 *
 * HP Jornada 710/720/729 Touchscreen Driver
 */

#include <linux/gpio/consumer.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/io.h>

#include <mach/jornada720.h>

MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson@gmail.com>");
MODULE_DESCRIPTION("HP Jornada 710/720/728 touchscreen driver");
MODULE_LICENSE("GPL v2");

struct jornada_ts {
        struct input_dev *dev;
        struct gpio_desc *gpio;
        int x_data[4];          /* X sample values */
        int y_data[4];          /* Y sample values */
};

static void jornada720_ts_collect_data(struct jornada_ts *jornada_ts)
{
        /* 3 low word X samples */
        jornada_ts->x_data[0] = jornada_ssp_byte(TXDUMMY);
        jornada_ts->x_data[1] = jornada_ssp_byte(TXDUMMY);
        jornada_ts->x_data[2] = jornada_ssp_byte(TXDUMMY);

        /* 3 low word Y samples */
        jornada_ts->y_data[0] = jornada_ssp_byte(TXDUMMY);
        jornada_ts->y_data[1] = jornada_ssp_byte(TXDUMMY);
        jornada_ts->y_data[2] = jornada_ssp_byte(TXDUMMY);

        /* combined x samples bits */
        jornada_ts->x_data[3] = jornada_ssp_byte(TXDUMMY);

        /* combined y samples bits */
        jornada_ts->y_data[3] = jornada_ssp_byte(TXDUMMY);
}

static int jornada720_ts_average(int coords[4])
{
        int coord, high_bits = coords[3];

        coord  = coords[0] | ((high_bits & 0x03) << 8);
        coord += coords[1] | ((high_bits & 0x0c) << 6);
        coord += coords[2] | ((high_bits & 0x30) << 4);

        return coord / 3;
}

static irqreturn_t jornada720_ts_interrupt(int irq, void *dev_id)
{
        struct platform_device *pdev = dev_id;
        struct jornada_ts *jornada_ts = platform_get_drvdata(pdev);
        struct input_dev *input = jornada_ts->dev;
        int x, y;

        /* If gpio is high then report pen up */
        if (gpiod_get_value(jornada_ts->gpio)) {
                input_report_key(input, BTN_TOUCH, 0);
                input_sync(input);
        } else {
                jornada_ssp_start();

                /* proper reply to request is always TXDUMMY */
                if (jornada_ssp_inout(GETTOUCHSAMPLES) == TXDUMMY) {
                        jornada720_ts_collect_data(jornada_ts);

                        x = jornada720_ts_average(jornada_ts->x_data);
                        y = jornada720_ts_average(jornada_ts->y_data);

                        input_report_key(input, BTN_TOUCH, 1);
                        input_report_abs(input, ABS_X, x);
                        input_report_abs(input, ABS_Y, y);
                        input_sync(input);
                }

                jornada_ssp_end();
        }

        return IRQ_HANDLED;
}

static int jornada720_ts_probe(struct platform_device *pdev)
{
        struct jornada_ts *jornada_ts;
        struct input_dev *input_dev;
        int error, irq;

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

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

        platform_set_drvdata(pdev, jornada_ts);

        jornada_ts->gpio = devm_gpiod_get(&pdev->dev, "penup", GPIOD_IN);
        if (IS_ERR(jornada_ts->gpio))
                return PTR_ERR(jornada_ts->gpio);

        irq = gpiod_to_irq(jornada_ts->gpio);
        if (irq <= 0)
                return irq < 0 ? irq : -EINVAL;

        jornada_ts->dev = input_dev;

        input_dev->name = "HP Jornada 7xx Touchscreen";
        input_dev->phys = "jornadats/input0";
        input_dev->id.bustype = BUS_HOST;
        input_dev->dev.parent = &pdev->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(input_dev, ABS_X, 270, 3900, 0, 0);
        input_set_abs_params(input_dev, ABS_Y, 180, 3700, 0, 0);

        error = devm_request_irq(&pdev->dev, irq, jornada720_ts_interrupt,
                                 IRQF_TRIGGER_RISING,
                                 "HP7XX Touchscreen driver", pdev);
        if (error) {
                dev_err(&pdev->dev, "HP7XX TS : Unable to acquire irq!\n");
                return error;
        }

        error = input_register_device(jornada_ts->dev);
        if (error)
                return error;

        return 0;
}

/* work with hotplug and coldplug */
MODULE_ALIAS("platform:jornada_ts");

static struct platform_driver jornada720_ts_driver = {
        .probe          = jornada720_ts_probe,
        .driver         = {
                .name   = "jornada_ts",
        },
};
module_platform_driver(jornada720_ts_driver);