da9052_tsi.c

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/*
 * TSI driver for Dialog DA9052
 *
 * Copyright(c) 2012 Dialog Semiconductor Ltd.
 *
 * Author: David Dajun Chen <[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;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 */
#include <linux/module.h>
#include <linux/input.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>

#include <linux/mfd/da9052/reg.h>
#include <linux/mfd/da9052/da9052.h>

#define TSI_PEN_DOWN_STATUS 0x40

struct da9052_tsi {
    struct da9052 *da9052;
    struct input_dev *dev;
    struct delayed_work ts_pen_work;
    struct mutex mutex;
    unsigned int irq_pendwn;
    unsigned int irq_datardy;
    bool stopped;
    bool adc_on;
};

static void da9052_ts_adc_toggle(struct da9052_tsi *tsi, bool on)
{
    da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0, on);
    tsi->adc_on = on;
}

static irqreturn_t da9052_ts_pendwn_irq(int irq, void *data)
{
    struct da9052_tsi *tsi = data;

    if (!tsi->stopped) {
        /* Mask PEN_DOWN event and unmask TSI_READY event */
        disable_irq_nosync(tsi->irq_pendwn);
        enable_irq(tsi->irq_datardy);

        da9052_ts_adc_toggle(tsi, true);

        schedule_delayed_work(&tsi->ts_pen_work, HZ / 50);
    }

    return IRQ_HANDLED;
}

static void da9052_ts_read(struct da9052_tsi *tsi)
{
    struct input_dev *input = tsi->dev;
    int ret;
    u16 x, y, z;
    u8 v;

    ret = da9052_reg_read(tsi->da9052, DA9052_TSI_X_MSB_REG);
    if (ret < 0)
        return;

    x = (u16) ret;

    ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Y_MSB_REG);
    if (ret < 0)
        return;

    y = (u16) ret;

    ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Z_MSB_REG);
    if (ret < 0)
        return;

    z = (u16) ret;

    ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
    if (ret < 0)
        return;

    v = (u8) ret;

    x = ((x << 2) & 0x3fc) | (v & 0x3);
    y = ((y << 2) & 0x3fc) | ((v & 0xc) >> 2);
    z = ((z << 2) & 0x3fc) | ((v & 0x30) >> 4);

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

static irqreturn_t da9052_ts_datardy_irq(int irq, void *data)
{
    struct da9052_tsi *tsi = data;

    da9052_ts_read(tsi);

    return IRQ_HANDLED;
}

static void da9052_ts_pen_work(struct work_struct *work)
{
    struct da9052_tsi *tsi = container_of(work, struct da9052_tsi,
                          ts_pen_work.work);
    if (!tsi->stopped) {
        int ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
        if (ret < 0 || (ret & TSI_PEN_DOWN_STATUS)) {
            /* Pen is still DOWN (or read error) */
            schedule_delayed_work(&tsi->ts_pen_work, HZ / 50);
        } else {
            struct input_dev *input = tsi->dev;

            /* Pen UP */
            da9052_ts_adc_toggle(tsi, false);

            /* Report Pen UP */
            input_report_key(input, BTN_TOUCH, 0);
            input_report_abs(input, ABS_PRESSURE, 0);
            input_sync(input);

            /*
             * FIXME: Fixes the unhandled irq issue when quick
             * pen down and pen up events occurs
             */
            ret = da9052_reg_update(tsi->da9052,
                        DA9052_EVENT_B_REG, 0xC0, 0xC0);
            if (ret < 0)
                return;

            /* Mask TSI_READY event and unmask PEN_DOWN event */
            disable_irq(tsi->irq_datardy);
            enable_irq(tsi->irq_pendwn);
        }
    }
}

static int __devinit da9052_ts_configure_gpio(struct da9052 *da9052)
{
    int error;

    error = da9052_reg_update(da9052, DA9052_GPIO_2_3_REG, 0x30, 0);
    if (error < 0)
        return error;

    error = da9052_reg_update(da9052, DA9052_GPIO_4_5_REG, 0x33, 0);
    if (error < 0)
        return error;

    error = da9052_reg_update(da9052, DA9052_GPIO_6_7_REG, 0x33, 0);
    if (error < 0)
        return error;

    return 0;
}

static int __devinit da9052_configure_tsi(struct da9052_tsi *tsi)
{
    int error;

    error = da9052_ts_configure_gpio(tsi->da9052);
    if (error)
        return error;

    /* Measure TSI sample every 1ms */
    error = da9052_reg_update(tsi->da9052, DA9052_ADC_CONT_REG,
                  1 << 6, 1 << 6);
    if (error < 0)
        return error;

    /* TSI_DELAY: 3 slots, TSI_SKIP: 0 slots, TSI_MODE: XYZP */
    error = da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 0xFC, 0xC0);
    if (error < 0)
        return error;

    /* Supply TSIRef through LD09 */
    error = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x59);
    if (error < 0)
        return error;

    return 0;
}

static int da9052_ts_input_open(struct input_dev *input_dev)
{
    struct da9052_tsi *tsi = input_get_drvdata(input_dev);

    tsi->stopped = false;
    mb();

    /* Unmask PEN_DOWN event */
    enable_irq(tsi->irq_pendwn);

    /* Enable Pen Detect Circuit */
    return da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG,
                 1 << 1, 1 << 1);
}

static void da9052_ts_input_close(struct input_dev *input_dev)
{
    struct da9052_tsi *tsi = input_get_drvdata(input_dev);

    tsi->stopped = true;
    mb();
    disable_irq(tsi->irq_pendwn);
    cancel_delayed_work_sync(&tsi->ts_pen_work);

    if (tsi->adc_on) {
        disable_irq(tsi->irq_datardy);
        da9052_ts_adc_toggle(tsi, false);

        /*
         * If ADC was on that means that pendwn IRQ was disabled
         * twice and we need to enable it to keep enable/disable
         * counter balanced. IRQ is still off though.
         */
        enable_irq(tsi->irq_pendwn);
    }

    /* Disable Pen Detect Circuit */
    da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 1, 0);
}

static int __devinit da9052_ts_probe(struct platform_device *pdev)
{
    struct da9052 *da9052;
    struct da9052_tsi *tsi;
    struct input_dev *input_dev;
    int irq_pendwn;
    int irq_datardy;
    int error;

    da9052 = dev_get_drvdata(pdev->dev.parent);
    if (!da9052)
        return -EINVAL;

    irq_pendwn = platform_get_irq_byname(pdev, "PENDWN");
    irq_datardy = platform_get_irq_byname(pdev, "TSIRDY");
    if (irq_pendwn < 0 || irq_datardy < 0) {
        dev_err(da9052->dev, "Unable to determine device interrupts\n");
        return -ENXIO;
    }

    tsi = kzalloc(sizeof(struct da9052_tsi), GFP_KERNEL);
    input_dev = input_allocate_device();
    if (!tsi || !input_dev) {
        error = -ENOMEM;
        goto err_free_mem;
    }

    tsi->da9052 = da9052;
    tsi->dev = input_dev;
    tsi->irq_pendwn = da9052->irq_base + irq_pendwn;
    tsi->irq_datardy = da9052->irq_base + irq_datardy;
    tsi->stopped = true;
    INIT_DELAYED_WORK(&tsi->ts_pen_work, da9052_ts_pen_work);

    input_dev->id.version = 0x0101;
    input_dev->id.vendor = 0x15B6;
    input_dev->id.product = 0x9052;
    input_dev->name = "Dialog DA9052 TouchScreen Driver";
    input_dev->dev.parent = &pdev->dev;
    input_dev->open = da9052_ts_input_open;
    input_dev->close = da9052_ts_input_close;

    __set_bit(EV_ABS, input_dev->evbit);
    __set_bit(EV_KEY, input_dev->evbit);
    __set_bit(BTN_TOUCH, input_dev->keybit);

    input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
    input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
    input_set_abs_params(input_dev, ABS_PRESSURE, 0, 1023, 0, 0);

    input_set_drvdata(input_dev, tsi);

    /* Disable Pen Detect Circuit */
    da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 1, 0);

    /* Disable ADC */
    da9052_ts_adc_toggle(tsi, false);

    error = request_threaded_irq(tsi->irq_pendwn,
                     NULL, da9052_ts_pendwn_irq,
                     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
                     "PENDWN", tsi);
    if (error) {
        dev_err(tsi->da9052->dev,
            "Failed to register PENDWN IRQ %d, error = %d\n",
            tsi->irq_pendwn, error);
        goto err_free_mem;
    }

    error = request_threaded_irq(tsi->irq_datardy,
                     NULL, da9052_ts_datardy_irq,
                     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
                     "TSIRDY", tsi);
    if (error) {
        dev_err(tsi->da9052->dev,
            "Failed to register TSIRDY IRQ %d, error = %d\n",
            tsi->irq_datardy, error);
        goto err_free_pendwn_irq;
    }

    /* Mask PEN_DOWN and TSI_READY events */
    disable_irq(tsi->irq_pendwn);
    disable_irq(tsi->irq_datardy);

    error = da9052_configure_tsi(tsi);
    if (error)
        goto err_free_datardy_irq;

    error = input_register_device(tsi->dev);
    if (error)
        goto err_free_datardy_irq;

    platform_set_drvdata(pdev, tsi);

    return 0;

err_free_datardy_irq:
    free_irq(tsi->irq_datardy, tsi);
err_free_pendwn_irq:
    free_irq(tsi->irq_pendwn, tsi);
err_free_mem:
    kfree(tsi);
    input_free_device(input_dev);

    return error;
}

static int  __devexit da9052_ts_remove(struct platform_device *pdev)
{
    struct da9052_tsi *tsi = platform_get_drvdata(pdev);

    da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);

    free_irq(tsi->irq_pendwn, tsi);
    free_irq(tsi->irq_datardy, tsi);

    input_unregister_device(tsi->dev);
    kfree(tsi);

    platform_set_drvdata(pdev, NULL);

    return 0;
}

static struct platform_driver da9052_tsi_driver = {
    .probe  = da9052_ts_probe,
    .remove = __devexit_p(da9052_ts_remove),
    .driver = {
        .name   = "da9052-tsi",
        .owner  = THIS_MODULE,
    },
};

module_platform_driver(da9052_tsi_driver);

MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9052");
MODULE_AUTHOR("Anthony Olech <[email protected]>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9052-tsi");