hp680_ts_input.c

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#include <linux/input.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <asm/io.h>
#include <asm/delay.h>
#include <asm/adc.h>
#include <mach/hp6xx.h>

#define MODNAME "hp680_ts_input"

#define HP680_TS_ABS_X_MIN  40
#define HP680_TS_ABS_X_MAX  950
#define HP680_TS_ABS_Y_MIN  80
#define HP680_TS_ABS_Y_MAX  910

#define PHDR    0xa400012e
#define SCPDR   0xa4000136

static void do_softint(struct work_struct *work);

static struct input_dev *hp680_ts_dev;
static DECLARE_DELAYED_WORK(work, do_softint);

static void do_softint(struct work_struct *work)
{
    int absx = 0, absy = 0;
    u8 scpdr;
    int touched = 0;

    if (__raw_readb(PHDR) & PHDR_TS_PEN_DOWN) {
        scpdr = __raw_readb(SCPDR);
        scpdr |= SCPDR_TS_SCAN_ENABLE;
        scpdr &= ~SCPDR_TS_SCAN_Y;
        __raw_writeb(scpdr, SCPDR);
        udelay(30);

        absy = adc_single(ADC_CHANNEL_TS_Y);

        scpdr = __raw_readb(SCPDR);
        scpdr |= SCPDR_TS_SCAN_Y;
        scpdr &= ~SCPDR_TS_SCAN_X;
        __raw_writeb(scpdr, SCPDR);
        udelay(30);

        absx = adc_single(ADC_CHANNEL_TS_X);

        scpdr = __raw_readb(SCPDR);
        scpdr |= SCPDR_TS_SCAN_X;
        scpdr &= ~SCPDR_TS_SCAN_ENABLE;
        __raw_writeb(scpdr, SCPDR);
        udelay(100);
        touched = __raw_readb(PHDR) & PHDR_TS_PEN_DOWN;
    }

    if (touched) {
        input_report_key(hp680_ts_dev, BTN_TOUCH, 1);
        input_report_abs(hp680_ts_dev, ABS_X, absx);
        input_report_abs(hp680_ts_dev, ABS_Y, absy);
    } else {
        input_report_key(hp680_ts_dev, BTN_TOUCH, 0);
    }

    input_sync(hp680_ts_dev);
    enable_irq(HP680_TS_IRQ);
}

static irqreturn_t hp680_ts_interrupt(int irq, void *dev)
{
    disable_irq_nosync(irq);
    schedule_delayed_work(&work, HZ / 20);

    return IRQ_HANDLED;
}

static int __init hp680_ts_init(void)
{
    int err;

    hp680_ts_dev = input_allocate_device();
    if (!hp680_ts_dev)
        return -ENOMEM;

    hp680_ts_dev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
    hp680_ts_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

    input_set_abs_params(hp680_ts_dev, ABS_X,
        HP680_TS_ABS_X_MIN, HP680_TS_ABS_X_MAX, 0, 0);
    input_set_abs_params(hp680_ts_dev, ABS_Y,
        HP680_TS_ABS_Y_MIN, HP680_TS_ABS_Y_MAX, 0, 0);

    hp680_ts_dev->name = "HP Jornada touchscreen";
    hp680_ts_dev->phys = "hp680_ts/input0";

    if (request_irq(HP680_TS_IRQ, hp680_ts_interrupt,
            0, MODNAME, NULL) < 0) {
        printk(KERN_ERR "hp680_touchscreen.c: Can't allocate irq %d\n",
               HP680_TS_IRQ);
        err = -EBUSY;
        goto fail1;
    }

    err = input_register_device(hp680_ts_dev);
    if (err)
        goto fail2;

    return 0;

 fail2: free_irq(HP680_TS_IRQ, NULL);
    cancel_delayed_work_sync(&work);
 fail1: input_free_device(hp680_ts_dev);
    return err;
}

static void __exit hp680_ts_exit(void)
{
    free_irq(HP680_TS_IRQ, NULL);
    cancel_delayed_work_sync(&work);
    input_unregister_device(hp680_ts_dev);
}

module_init(hp680_ts_init);
module_exit(hp680_ts_exit);

MODULE_AUTHOR("Andriy Skulysh, [email protected]");
MODULE_DESCRIPTION("HP Jornada 680 touchscreen driver");
MODULE_LICENSE("GPL");