pixcir_i2c_ts.c

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/*
 * Driver for Pixcir I2C touchscreen controllers.
 *
 * Copyright (C) 2010-2011 Pixcir, Inc.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program 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/delay.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/input/pixcir_ts.h>

struct pixcir_i2c_ts_data {
    struct i2c_client *client;
    struct input_dev *input;
    const struct pixcir_ts_platform_data *chip;
    bool exiting;
};

static void pixcir_ts_poscheck(struct pixcir_i2c_ts_data *data)
{
    struct pixcir_i2c_ts_data *tsdata = data;
    u8 rdbuf[10], wrbuf[1] = { 0 };
    u8 touch;
    int ret;

    ret = i2c_master_send(tsdata->client, wrbuf, sizeof(wrbuf));
    if (ret != sizeof(wrbuf)) {
        dev_err(&tsdata->client->dev,
            "%s: i2c_master_send failed(), ret=%d\n",
            __func__, ret);
        return;
    }

    ret = i2c_master_recv(tsdata->client, rdbuf, sizeof(rdbuf));
    if (ret != sizeof(rdbuf)) {
        dev_err(&tsdata->client->dev,
            "%s: i2c_master_recv failed(), ret=%d\n",
            __func__, ret);
        return;
    }

    touch = rdbuf[0];
    if (touch) {
        u16 posx1 = (rdbuf[3] << 8) | rdbuf[2];
        u16 posy1 = (rdbuf[5] << 8) | rdbuf[4];
        u16 posx2 = (rdbuf[7] << 8) | rdbuf[6];
        u16 posy2 = (rdbuf[9] << 8) | rdbuf[8];

        input_report_key(tsdata->input, BTN_TOUCH, 1);
        input_report_abs(tsdata->input, ABS_X, posx1);
        input_report_abs(tsdata->input, ABS_Y, posy1);

        input_report_abs(tsdata->input, ABS_MT_POSITION_X, posx1);
        input_report_abs(tsdata->input, ABS_MT_POSITION_Y, posy1);
        input_mt_sync(tsdata->input);

        if (touch == 2) {
            input_report_abs(tsdata->input,
                     ABS_MT_POSITION_X, posx2);
            input_report_abs(tsdata->input,
                     ABS_MT_POSITION_Y, posy2);
            input_mt_sync(tsdata->input);
        }
    } else {
        input_report_key(tsdata->input, BTN_TOUCH, 0);
    }

    input_sync(tsdata->input);
}

static irqreturn_t pixcir_ts_isr(int irq, void *dev_id)
{
    struct pixcir_i2c_ts_data *tsdata = dev_id;

    while (!tsdata->exiting) {
        pixcir_ts_poscheck(tsdata);

        if (tsdata->chip->attb_read_val())
            break;

        msleep(20);
    }

    return IRQ_HANDLED;
}

#ifdef CONFIG_PM_SLEEP
static int pixcir_i2c_ts_suspend(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);

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

    return 0;
}

static int pixcir_i2c_ts_resume(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);

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

    return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(pixcir_dev_pm_ops,
             pixcir_i2c_ts_suspend, pixcir_i2c_ts_resume);

static int __devinit pixcir_i2c_ts_probe(struct i2c_client *client,
                     const struct i2c_device_id *id)
{
    const struct pixcir_ts_platform_data *pdata = client->dev.platform_data;
    struct pixcir_i2c_ts_data *tsdata;
    struct input_dev *input;
    int error;

    if (!pdata) {
        dev_err(&client->dev, "platform data not defined\n");
        return -EINVAL;
    }

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

    tsdata->client = client;
    tsdata->input = input;
    tsdata->chip = pdata;

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

    __set_bit(EV_KEY, input->evbit);
    __set_bit(EV_ABS, input->evbit);
    __set_bit(BTN_TOUCH, input->keybit);
    input_set_abs_params(input, ABS_X, 0, pdata->x_max, 0, 0);
    input_set_abs_params(input, ABS_Y, 0, pdata->y_max, 0, 0);
    input_set_abs_params(input, ABS_MT_POSITION_X, 0, pdata->x_max, 0, 0);
    input_set_abs_params(input, ABS_MT_POSITION_Y, 0, pdata->y_max, 0, 0);

    input_set_drvdata(input, tsdata);

    error = request_threaded_irq(client->irq, NULL, pixcir_ts_isr,
                     IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
                     client->name, tsdata);
    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, tsdata);
    device_init_wakeup(&client->dev, 1);

    return 0;

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

static int __devexit pixcir_i2c_ts_remove(struct i2c_client *client)
{
    struct pixcir_i2c_ts_data *tsdata = i2c_get_clientdata(client);

    device_init_wakeup(&client->dev, 0);

    tsdata->exiting = true;
    mb();
    free_irq(client->irq, tsdata);

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

    return 0;
}

static const struct i2c_device_id pixcir_i2c_ts_id[] = {
    { "pixcir_ts", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, pixcir_i2c_ts_id);

static struct i2c_driver pixcir_i2c_ts_driver = {
    .driver = {
        .owner  = THIS_MODULE,
        .name   = "pixcir_ts",
        .pm = &pixcir_dev_pm_ops,
    },
    .probe      = pixcir_i2c_ts_probe,
    .remove     = __devexit_p(pixcir_i2c_ts_remove),
    .id_table   = pixcir_i2c_ts_id,
};

module_i2c_driver(pixcir_i2c_ts_driver);

MODULE_AUTHOR("Jianchun Bian <[email protected]>, Dequan Meng <[email protected]>");
MODULE_DESCRIPTION("Pixcir I2C Touchscreen Driver");
MODULE_LICENSE("GPL");