jornada720_ts.c

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/*
 * drivers/input/touchscreen/jornada720_ts.c
 *
 * Copyright (C) 2007 Kristoffer Ericson <[email protected]>
 *
 *  Copyright (C) 2006 Filip Zyzniewski <[email protected]>
 *  based on HP Jornada 56x touchscreen driver by Alex Lange <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * HP Jornada 710/720/729 Touchscreen Driver
 */

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

#include <mach/hardware.h>
#include <mach/jornada720.h>
#include <mach/irqs.h>

MODULE_AUTHOR("Kristoffer Ericson <[email protected]>");
MODULE_DESCRIPTION("HP Jornada 710/720/728 touchscreen driver");
MODULE_LICENSE("GPL v2");

struct jornada_ts {
    struct input_dev *dev;
    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_GPIO9 is set to high then report pen up */
    if (GPLR & GPIO_GPIO(9)) {
        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 __devinit jornada720_ts_probe(struct platform_device *pdev)
{
    struct jornada_ts *jornada_ts;
    struct input_dev *input_dev;
    int error;

    jornada_ts = kzalloc(sizeof(struct jornada_ts), GFP_KERNEL);
    input_dev = input_allocate_device();

    if (!jornada_ts || !input_dev) {
        error = -ENOMEM;
        goto fail1;
    }

    platform_set_drvdata(pdev, jornada_ts);

    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 = request_irq(IRQ_GPIO9,
            jornada720_ts_interrupt,
            IRQF_TRIGGER_RISING,
            "HP7XX Touchscreen driver", pdev);
    if (error) {
        printk(KERN_INFO "HP7XX TS : Unable to acquire irq!\n");
        goto fail1;
    }

    error = input_register_device(jornada_ts->dev);
    if (error)
        goto fail2;

    return 0;

 fail2:
    free_irq(IRQ_GPIO9, pdev);
 fail1:
    platform_set_drvdata(pdev, NULL);
    input_free_device(input_dev);
    kfree(jornada_ts);
    return error;
}

static int __devexit jornada720_ts_remove(struct platform_device *pdev)
{
    struct jornada_ts *jornada_ts = platform_get_drvdata(pdev);

    free_irq(IRQ_GPIO9, pdev);
    platform_set_drvdata(pdev, NULL);
    input_unregister_device(jornada_ts->dev);
    kfree(jornada_ts);

    return 0;
}

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

static struct platform_driver jornada720_ts_driver = {
    .probe      = jornada720_ts_probe,
    .remove     = __devexit_p(jornada720_ts_remove),
    .driver     = {
        .name   = "jornada_ts",
        .owner  = THIS_MODULE,
    },
};
module_platform_driver(jornada720_ts_driver);