w90p910_ts.c

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/*
 * Copyright (c) 2008 Nuvoton technology corporation.
 *
 * Wan ZongShun <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation;version 2 of the License.
 *
 */

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

/* ADC controller bit defines */
#define ADC_DELAY   0xf00
#define ADC_DOWN    0x01
#define ADC_TSC_Y   (0x01 << 8)
#define ADC_TSC_X   (0x00 << 8)
#define TSC_FOURWIRE    (~(0x03 << 1))
#define ADC_CLK_EN  (0x01 << 28)    /* ADC clock enable */
#define ADC_READ_CON    (0x01 << 12)
#define ADC_CONV    (0x01 << 13)
#define ADC_SEMIAUTO    (0x01 << 14)
#define ADC_WAITTRIG    (0x03 << 14)
#define ADC_RST1    (0x01 << 16)
#define ADC_RST0    (0x00 << 16)
#define ADC_EN      (0x01 << 17)
#define ADC_INT     (0x01 << 18)
#define WT_INT      (0x01 << 20)
#define ADC_INT_EN  (0x01 << 21)
#define LVD_INT_EN  (0x01 << 22)
#define WT_INT_EN   (0x01 << 23)
#define ADC_DIV     (0x04 << 1) /* div = 6 */

enum ts_state {
    TS_WAIT_NEW_PACKET, /* We are waiting next touch report */
    TS_WAIT_X_COORD,    /* We are waiting for ADC to report X coord */
    TS_WAIT_Y_COORD,    /* We are waiting for ADC to report Y coord */
    TS_IDLE,        /* Input device is closed, don't do anything */
};

struct w90p910_ts {
    struct input_dev *input;
    struct timer_list timer;
    struct clk *clk;
    int irq_num;
    void __iomem *ts_reg;
    spinlock_t lock;
    enum ts_state state;
};

static void w90p910_report_event(struct w90p910_ts *w90p910_ts, bool down)
{
    struct input_dev *dev = w90p910_ts->input;

    if (down) {
        input_report_abs(dev, ABS_X,
                 __raw_readl(w90p910_ts->ts_reg + 0x0c));
        input_report_abs(dev, ABS_Y,
                 __raw_readl(w90p910_ts->ts_reg + 0x10));
    }

    input_report_key(dev, BTN_TOUCH, down);
    input_sync(dev);
}

static void w90p910_prepare_x_reading(struct w90p910_ts *w90p910_ts)
{
    unsigned long ctlreg;

    __raw_writel(ADC_TSC_X, w90p910_ts->ts_reg + 0x04);
    ctlreg = __raw_readl(w90p910_ts->ts_reg);
    ctlreg &= ~(ADC_WAITTRIG | WT_INT | WT_INT_EN);
    ctlreg |= ADC_SEMIAUTO | ADC_INT_EN | ADC_CONV;
    __raw_writel(ctlreg, w90p910_ts->ts_reg);

    w90p910_ts->state = TS_WAIT_X_COORD;
}

static void w90p910_prepare_y_reading(struct w90p910_ts *w90p910_ts)
{
    unsigned long ctlreg;

    __raw_writel(ADC_TSC_Y, w90p910_ts->ts_reg + 0x04);
    ctlreg = __raw_readl(w90p910_ts->ts_reg);
    ctlreg &= ~(ADC_WAITTRIG | ADC_INT | WT_INT_EN);
    ctlreg |= ADC_SEMIAUTO | ADC_INT_EN | ADC_CONV;
    __raw_writel(ctlreg, w90p910_ts->ts_reg);

    w90p910_ts->state = TS_WAIT_Y_COORD;
}

static void w90p910_prepare_next_packet(struct w90p910_ts *w90p910_ts)
{
    unsigned long ctlreg;

    ctlreg = __raw_readl(w90p910_ts->ts_reg);
    ctlreg &= ~(ADC_INT | ADC_INT_EN | ADC_SEMIAUTO | ADC_CONV);
    ctlreg |= ADC_WAITTRIG | WT_INT_EN;
    __raw_writel(ctlreg, w90p910_ts->ts_reg);

    w90p910_ts->state = TS_WAIT_NEW_PACKET;
}

static irqreturn_t w90p910_ts_interrupt(int irq, void *dev_id)
{
    struct w90p910_ts *w90p910_ts = dev_id;
    unsigned long flags;

    spin_lock_irqsave(&w90p910_ts->lock, flags);

    switch (w90p910_ts->state) {
    case TS_WAIT_NEW_PACKET:
        /*
         * The controller only generates interrupts when pen
         * is down.
         */
        del_timer(&w90p910_ts->timer);
        w90p910_prepare_x_reading(w90p910_ts);
        break;


    case TS_WAIT_X_COORD:
        w90p910_prepare_y_reading(w90p910_ts);
        break;

    case TS_WAIT_Y_COORD:
        w90p910_report_event(w90p910_ts, true);
        w90p910_prepare_next_packet(w90p910_ts);
        mod_timer(&w90p910_ts->timer, jiffies + msecs_to_jiffies(100));
        break;

    case TS_IDLE:
        break;
    }

    spin_unlock_irqrestore(&w90p910_ts->lock, flags);

    return IRQ_HANDLED;
}

static void w90p910_check_pen_up(unsigned long data)
{
    struct w90p910_ts *w90p910_ts = (struct w90p910_ts *) data;
    unsigned long flags;

    spin_lock_irqsave(&w90p910_ts->lock, flags);

    if (w90p910_ts->state == TS_WAIT_NEW_PACKET &&
        !(__raw_readl(w90p910_ts->ts_reg + 0x04) & ADC_DOWN)) {

        w90p910_report_event(w90p910_ts, false);
    }

    spin_unlock_irqrestore(&w90p910_ts->lock, flags);
}

static int w90p910_open(struct input_dev *dev)
{
    struct w90p910_ts *w90p910_ts = input_get_drvdata(dev);
    unsigned long val;

    /* enable the ADC clock */
    clk_enable(w90p910_ts->clk);

    __raw_writel(ADC_RST1, w90p910_ts->ts_reg);
    msleep(1);
    __raw_writel(ADC_RST0, w90p910_ts->ts_reg);
    msleep(1);

    /* set delay and screen type */
    val = __raw_readl(w90p910_ts->ts_reg + 0x04);
    __raw_writel(val & TSC_FOURWIRE, w90p910_ts->ts_reg + 0x04);
    __raw_writel(ADC_DELAY, w90p910_ts->ts_reg + 0x08);

    w90p910_ts->state = TS_WAIT_NEW_PACKET;
    wmb();

    /* set trigger mode */
    val = __raw_readl(w90p910_ts->ts_reg);
    val |= ADC_WAITTRIG | ADC_DIV | ADC_EN | WT_INT_EN;
    __raw_writel(val, w90p910_ts->ts_reg);

    return 0;
}

static void w90p910_close(struct input_dev *dev)
{
    struct w90p910_ts *w90p910_ts = input_get_drvdata(dev);
    unsigned long val;

    /* disable trigger mode */

    spin_lock_irq(&w90p910_ts->lock);

    w90p910_ts->state = TS_IDLE;

    val = __raw_readl(w90p910_ts->ts_reg);
    val &= ~(ADC_WAITTRIG | ADC_DIV | ADC_EN | WT_INT_EN | ADC_INT_EN);
    __raw_writel(val, w90p910_ts->ts_reg);

    spin_unlock_irq(&w90p910_ts->lock);

    /* Now that interrupts are shut off we can safely delete timer */
    del_timer_sync(&w90p910_ts->timer);

    /* stop the ADC clock */
    clk_disable(w90p910_ts->clk);
}

static int __devinit w90x900ts_probe(struct platform_device *pdev)
{
    struct w90p910_ts *w90p910_ts;
    struct input_dev *input_dev;
    struct resource *res;
    int err;

    w90p910_ts = kzalloc(sizeof(struct w90p910_ts), GFP_KERNEL);
    input_dev = input_allocate_device();
    if (!w90p910_ts || !input_dev) {
        err = -ENOMEM;
        goto fail1;
    }

    w90p910_ts->input = input_dev;
    w90p910_ts->state = TS_IDLE;
    spin_lock_init(&w90p910_ts->lock);
    setup_timer(&w90p910_ts->timer, w90p910_check_pen_up,
            (unsigned long)w90p910_ts);

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res) {
        err = -ENXIO;
        goto fail1;
    }

    if (!request_mem_region(res->start, resource_size(res),
                pdev->name)) {
        err = -EBUSY;
        goto fail1;
    }

    w90p910_ts->ts_reg = ioremap(res->start, resource_size(res));
    if (!w90p910_ts->ts_reg) {
        err = -ENOMEM;
        goto fail2;
    }

    w90p910_ts->clk = clk_get(&pdev->dev, NULL);
    if (IS_ERR(w90p910_ts->clk)) {
        err = PTR_ERR(w90p910_ts->clk);
        goto fail3;
    }

    input_dev->name = "W90P910 TouchScreen";
    input_dev->phys = "w90p910ts/event0";
    input_dev->id.bustype = BUS_HOST;
    input_dev->id.vendor  = 0x0005;
    input_dev->id.product = 0x0001;
    input_dev->id.version = 0x0100;
    input_dev->dev.parent = &pdev->dev;
    input_dev->open = w90p910_open;
    input_dev->close = w90p910_close;

    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, 0, 0x400, 0, 0);
    input_set_abs_params(input_dev, ABS_Y, 0, 0x400, 0, 0);

    input_set_drvdata(input_dev, w90p910_ts);

    w90p910_ts->irq_num = platform_get_irq(pdev, 0);
    if (request_irq(w90p910_ts->irq_num, w90p910_ts_interrupt,
            0, "w90p910ts", w90p910_ts)) {
        err = -EBUSY;
        goto fail4;
    }

    err = input_register_device(w90p910_ts->input);
    if (err)
        goto fail5;

    platform_set_drvdata(pdev, w90p910_ts);

    return 0;

fail5:  free_irq(w90p910_ts->irq_num, w90p910_ts);
fail4:  clk_put(w90p910_ts->clk);
fail3:  iounmap(w90p910_ts->ts_reg);
fail2:  release_mem_region(res->start, resource_size(res));
fail1:  input_free_device(input_dev);
    kfree(w90p910_ts);
    return err;
}

static int __devexit w90x900ts_remove(struct platform_device *pdev)
{
    struct w90p910_ts *w90p910_ts = platform_get_drvdata(pdev);
    struct resource *res;

    free_irq(w90p910_ts->irq_num, w90p910_ts);
    del_timer_sync(&w90p910_ts->timer);
    iounmap(w90p910_ts->ts_reg);

    clk_put(w90p910_ts->clk);

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    release_mem_region(res->start, resource_size(res));

    input_unregister_device(w90p910_ts->input);
    kfree(w90p910_ts);

    platform_set_drvdata(pdev, NULL);

    return 0;
}

static struct platform_driver w90x900ts_driver = {
    .probe      = w90x900ts_probe,
    .remove     = __devexit_p(w90x900ts_remove),
    .driver     = {
        .name   = "nuc900-ts",
        .owner  = THIS_MODULE,
    },
};
module_platform_driver(w90x900ts_driver);

MODULE_AUTHOR("Wan ZongShun <[email protected]>");
MODULE_DESCRIPTION("w90p910 touch screen driver!");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:nuc900-ts");