migor_ts.c

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/*
 * Touch Screen driver for Renesas MIGO-R Platform
 *
 * Copyright (c) 2008 Magnus Damm
 * Copyright (c) 2007 Ujjwal Pande <[email protected]>,
 *  Kenati Technologies Pvt Ltd.
 *
 * This file 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.
 *
 * This file is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <asm/io.h>
#include <linux/i2c.h>
#include <linux/timer.h>

#define EVENT_PENDOWN 1
#define EVENT_REPEAT  2
#define EVENT_PENUP   3

struct migor_ts_priv {
    struct i2c_client *client;
    struct input_dev *input;
    int irq;
};

static const u_int8_t migor_ts_ena_seq[17] = { 0x33, 0x22, 0x11,
                           0x01, 0x06, 0x07, };
static const u_int8_t migor_ts_dis_seq[17] = { };

static irqreturn_t migor_ts_isr(int irq, void *dev_id)
{
    struct migor_ts_priv *priv = dev_id;
    unsigned short xpos, ypos;
    unsigned char event;
    u_int8_t buf[16];

    /*
     * The touch screen controller chip is hooked up to the CPU
     * using I2C and a single interrupt line. The interrupt line
     * is pulled low whenever someone taps the screen. To deassert
     * the interrupt line we need to acknowledge the interrupt by
     * communicating with the controller over the slow i2c bus.
     *
     * Since I2C bus controller may sleep we are using threaded
     * IRQ here.
     */

    memset(buf, 0, sizeof(buf));

    /* Set Index 0 */
    buf[0] = 0;
    if (i2c_master_send(priv->client, buf, 1) != 1) {
        dev_err(&priv->client->dev, "Unable to write i2c index\n");
        goto out;
    }

    /* Now do Page Read */
    if (i2c_master_recv(priv->client, buf, sizeof(buf)) != sizeof(buf)) {
        dev_err(&priv->client->dev, "Unable to read i2c page\n");
        goto out;
    }

    ypos = ((buf[9] & 0x03) << 8 | buf[8]);
    xpos = ((buf[11] & 0x03) << 8 | buf[10]);
    event = buf[12];

    switch (event) {
    case EVENT_PENDOWN:
    case EVENT_REPEAT:
        input_report_key(priv->input, BTN_TOUCH, 1);
        input_report_abs(priv->input, ABS_X, ypos); /*X-Y swap*/
        input_report_abs(priv->input, ABS_Y, xpos);
        input_sync(priv->input);
        break;

    case EVENT_PENUP:
        input_report_key(priv->input, BTN_TOUCH, 0);
        input_sync(priv->input);
        break;
    }

 out:
    return IRQ_HANDLED;
}

static int migor_ts_open(struct input_dev *dev)
{
    struct migor_ts_priv *priv = input_get_drvdata(dev);
    struct i2c_client *client = priv->client;
    int count;

    /* enable controller */
    count = i2c_master_send(client, migor_ts_ena_seq,
                sizeof(migor_ts_ena_seq));
    if (count != sizeof(migor_ts_ena_seq)) {
        dev_err(&client->dev, "Unable to enable touchscreen.\n");
        return -ENXIO;
    }

    return 0;
}

static void migor_ts_close(struct input_dev *dev)
{
    struct migor_ts_priv *priv = input_get_drvdata(dev);
    struct i2c_client *client = priv->client;

    disable_irq(priv->irq);

    /* disable controller */
    i2c_master_send(client, migor_ts_dis_seq, sizeof(migor_ts_dis_seq));

    enable_irq(priv->irq);
}

static int migor_ts_probe(struct i2c_client *client,
              const struct i2c_device_id *idp)
{
    struct migor_ts_priv *priv;
    struct input_dev *input;
    int error;

    priv = kzalloc(sizeof(*priv), GFP_KERNEL);
    input = input_allocate_device();
    if (!priv || !input) {
        dev_err(&client->dev, "failed to allocate memory\n");
        error = -ENOMEM;
        goto err_free_mem;
    }

    priv->client = client;
    priv->input = input;
    priv->irq = client->irq;

    input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);

    __set_bit(BTN_TOUCH, input->keybit);

    input_set_abs_params(input, ABS_X, 95, 955, 0, 0);
    input_set_abs_params(input, ABS_Y, 85, 935, 0, 0);

    input->name = client->name;
    input->id.bustype = BUS_I2C;
    input->dev.parent = &client->dev;

    input->open = migor_ts_open;
    input->close = migor_ts_close;

    input_set_drvdata(input, priv);

    error = request_threaded_irq(priv->irq, NULL, migor_ts_isr,
                                     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
                                     client->name, priv);
    if (error) {
        dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
        goto err_free_mem;
    }

    error = input_register_device(input);
    if (error)
        goto err_free_irq;

    i2c_set_clientdata(client, priv);
    device_init_wakeup(&client->dev, 1);

    return 0;

 err_free_irq:
    free_irq(priv->irq, priv);
 err_free_mem:
    input_free_device(input);
    kfree(priv);
    return error;
}

static int migor_ts_remove(struct i2c_client *client)
{
    struct migor_ts_priv *priv = i2c_get_clientdata(client);

    free_irq(priv->irq, priv);
    input_unregister_device(priv->input);
    kfree(priv);

    dev_set_drvdata(&client->dev, NULL);

    return 0;
}

static int migor_ts_suspend(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct migor_ts_priv *priv = i2c_get_clientdata(client);

    if (device_may_wakeup(&client->dev))
        enable_irq_wake(priv->irq);

    return 0;
}

static int migor_ts_resume(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct migor_ts_priv *priv = i2c_get_clientdata(client);

    if (device_may_wakeup(&client->dev))
        disable_irq_wake(priv->irq);

    return 0;
}

static SIMPLE_DEV_PM_OPS(migor_ts_pm, migor_ts_suspend, migor_ts_resume);

static const struct i2c_device_id migor_ts_id[] = {
    { "migor_ts", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, migor_ts);

static struct i2c_driver migor_ts_driver = {
    .driver = {
        .name = "migor_ts",
        .pm = &migor_ts_pm,
    },
    .probe = migor_ts_probe,
    .remove = migor_ts_remove,
    .id_table = migor_ts_id,
};

module_i2c_driver(migor_ts_driver);

MODULE_DESCRIPTION("MigoR Touchscreen driver");
MODULE_AUTHOR("Magnus Damm <[email protected]>");
MODULE_LICENSE("GPL");