root/drivers/input/touchscreen/htcpen.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * HTC Shift touchscreen driver
 *
 * Copyright (C) 2008 Pau Oliva Fora <pof@eslack.org>
 */

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/isa.h>
#include <linux/ioport.h>
#include <linux/dmi.h>

MODULE_AUTHOR("Pau Oliva Fora <pau@eslack.org>");
MODULE_DESCRIPTION("HTC Shift touchscreen driver");
MODULE_LICENSE("GPL");

#define HTCPEN_PORT_IRQ_CLEAR   0x068
#define HTCPEN_PORT_INIT        0x06c
#define HTCPEN_PORT_INDEX       0x0250
#define HTCPEN_PORT_DATA        0x0251
#define HTCPEN_IRQ              3

#define DEVICE_ENABLE           0xa2
#define DEVICE_DISABLE          0xa3

#define X_INDEX                 3
#define Y_INDEX                 5
#define TOUCH_INDEX             0xb
#define LSB_XY_INDEX            0xc
#define X_AXIS_MAX              2040
#define Y_AXIS_MAX              2040

static bool invert_x;
module_param(invert_x, bool, 0644);
MODULE_PARM_DESC(invert_x, "If set, X axis is inverted");
static bool invert_y;
module_param(invert_y, bool, 0644);
MODULE_PARM_DESC(invert_y, "If set, Y axis is inverted");

static irqreturn_t htcpen_interrupt(int irq, void *handle)
{
        struct input_dev *htcpen_dev = handle;
        unsigned short x, y, xy;

        /* 0 = press; 1 = release */
        outb_p(TOUCH_INDEX, HTCPEN_PORT_INDEX);

        if (inb_p(HTCPEN_PORT_DATA)) {
                input_report_key(htcpen_dev, BTN_TOUCH, 0);
        } else {
                outb_p(X_INDEX, HTCPEN_PORT_INDEX);
                x = inb_p(HTCPEN_PORT_DATA);

                outb_p(Y_INDEX, HTCPEN_PORT_INDEX);
                y = inb_p(HTCPEN_PORT_DATA);

                outb_p(LSB_XY_INDEX, HTCPEN_PORT_INDEX);
                xy = inb_p(HTCPEN_PORT_DATA);

                /* get high resolution value of X and Y using LSB */
                x = X_AXIS_MAX - ((x * 8) + ((xy >> 4) & 0xf));
                y = (y * 8) + (xy & 0xf);
                if (invert_x)
                        x = X_AXIS_MAX - x;
                if (invert_y)
                        y = Y_AXIS_MAX - y;

                if (x != X_AXIS_MAX && x != 0) {
                        input_report_key(htcpen_dev, BTN_TOUCH, 1);
                        input_report_abs(htcpen_dev, ABS_X, x);
                        input_report_abs(htcpen_dev, ABS_Y, y);
                }
        }

        input_sync(htcpen_dev);

        inb_p(HTCPEN_PORT_IRQ_CLEAR);

        return IRQ_HANDLED;
}

static int htcpen_open(struct input_dev *dev)
{
        outb_p(DEVICE_ENABLE, HTCPEN_PORT_INIT);

        return 0;
}

static void htcpen_close(struct input_dev *dev)
{
        outb_p(DEVICE_DISABLE, HTCPEN_PORT_INIT);
        synchronize_irq(HTCPEN_IRQ);
}

static int htcpen_isa_probe(struct device *dev, unsigned int id)
{
        struct input_dev *htcpen_dev;
        int err = -EBUSY;

        if (!request_region(HTCPEN_PORT_IRQ_CLEAR, 1, "htcpen")) {
                printk(KERN_ERR "htcpen: unable to get IO region 0x%x\n",
                        HTCPEN_PORT_IRQ_CLEAR);
                goto request_region1_failed;
        }

        if (!request_region(HTCPEN_PORT_INIT, 1, "htcpen")) {
                printk(KERN_ERR "htcpen: unable to get IO region 0x%x\n",
                        HTCPEN_PORT_INIT);
                goto request_region2_failed;
        }

        if (!request_region(HTCPEN_PORT_INDEX, 2, "htcpen")) {
                printk(KERN_ERR "htcpen: unable to get IO region 0x%x\n",
                        HTCPEN_PORT_INDEX);
                goto request_region3_failed;
        }

        htcpen_dev = input_allocate_device();
        if (!htcpen_dev) {
                printk(KERN_ERR "htcpen: can't allocate device\n");
                err = -ENOMEM;
                goto input_alloc_failed;
        }

        htcpen_dev->name = "HTC Shift EC TouchScreen";
        htcpen_dev->id.bustype = BUS_ISA;

        htcpen_dev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
        htcpen_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
        input_set_abs_params(htcpen_dev, ABS_X, 0, X_AXIS_MAX, 0, 0);
        input_set_abs_params(htcpen_dev, ABS_Y, 0, Y_AXIS_MAX, 0, 0);

        htcpen_dev->open = htcpen_open;
        htcpen_dev->close = htcpen_close;

        err = request_irq(HTCPEN_IRQ, htcpen_interrupt, 0, "htcpen",
                        htcpen_dev);
        if (err) {
                printk(KERN_ERR "htcpen: irq busy\n");
                goto request_irq_failed;
        }

        inb_p(HTCPEN_PORT_IRQ_CLEAR);

        err = input_register_device(htcpen_dev);
        if (err)
                goto input_register_failed;

        dev_set_drvdata(dev, htcpen_dev);

        return 0;

 input_register_failed:
        free_irq(HTCPEN_IRQ, htcpen_dev);
 request_irq_failed:
        input_free_device(htcpen_dev);
 input_alloc_failed:
        release_region(HTCPEN_PORT_INDEX, 2);
 request_region3_failed:
        release_region(HTCPEN_PORT_INIT, 1);
 request_region2_failed:
        release_region(HTCPEN_PORT_IRQ_CLEAR, 1);
 request_region1_failed:
        return err;
}

static void htcpen_isa_remove(struct device *dev, unsigned int id)
{
        struct input_dev *htcpen_dev = dev_get_drvdata(dev);

        input_unregister_device(htcpen_dev);

        free_irq(HTCPEN_IRQ, htcpen_dev);

        release_region(HTCPEN_PORT_INDEX, 2);
        release_region(HTCPEN_PORT_INIT, 1);
        release_region(HTCPEN_PORT_IRQ_CLEAR, 1);
}

#ifdef CONFIG_PM
static int htcpen_isa_suspend(struct device *dev, unsigned int n,
                                pm_message_t state)
{
        outb_p(DEVICE_DISABLE, HTCPEN_PORT_INIT);

        return 0;
}

static int htcpen_isa_resume(struct device *dev, unsigned int n)
{
        outb_p(DEVICE_ENABLE, HTCPEN_PORT_INIT);

        return 0;
}
#endif

static struct isa_driver htcpen_isa_driver = {
        .probe          = htcpen_isa_probe,
        .remove         = htcpen_isa_remove,
#ifdef CONFIG_PM
        .suspend        = htcpen_isa_suspend,
        .resume         = htcpen_isa_resume,
#endif
        .driver = {
                .owner  = THIS_MODULE,
                .name   = "htcpen",
        }
};

static const struct dmi_system_id htcshift_dmi_table[] __initconst = {
        {
                .ident = "Shift",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "High Tech Computer Corp"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "Shift"),
                },
        },
        { }
};
MODULE_DEVICE_TABLE(dmi, htcshift_dmi_table);

static int __init htcpen_isa_init(void)
{
        if (!dmi_check_system(htcshift_dmi_table))
                return -ENODEV;

        return isa_register_driver(&htcpen_isa_driver, 1);
}

static void __exit htcpen_isa_exit(void)
{
        isa_unregister_driver(&htcpen_isa_driver);
}

module_init(htcpen_isa_init);
module_exit(htcpen_isa_exit);