cy8ctmg110_ts.c

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/*
 * Driver for cypress touch screen controller
 *
 * Copyright (c) 2009 Aava Mobile
 *
 * Some cleanups by Alan Cox <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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 program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/i2c.h>
#include <linux/gpio.h>
#include <linux/input/cy8ctmg110_pdata.h>

#define CY8CTMG110_DRIVER_NAME      "cy8ctmg110"

/* Touch coordinates */
#define CY8CTMG110_X_MIN        0
#define CY8CTMG110_Y_MIN        0
#define CY8CTMG110_X_MAX        759
#define CY8CTMG110_Y_MAX        465


/* cy8ctmg110 register definitions */
#define CY8CTMG110_TOUCH_WAKEUP_TIME    0
#define CY8CTMG110_TOUCH_SLEEP_TIME 2
#define CY8CTMG110_TOUCH_X1     3
#define CY8CTMG110_TOUCH_Y1     5
#define CY8CTMG110_TOUCH_X2     7
#define CY8CTMG110_TOUCH_Y2     9
#define CY8CTMG110_FINGERS      11
#define CY8CTMG110_GESTURE      12
#define CY8CTMG110_REG_MAX      13


/*
 * The touch driver structure.
 */
struct cy8ctmg110 {
    struct input_dev *input;
    char phys[32];
    struct i2c_client *client;
    int reset_pin;
    int irq_pin;
};

/*
 * cy8ctmg110_power is the routine that is called when touch hardware
 * will powered off or on.
 */
static void cy8ctmg110_power(struct cy8ctmg110 *ts, bool poweron)
{
    if (ts->reset_pin)
        gpio_direction_output(ts->reset_pin, 1 - poweron);
}

static int cy8ctmg110_write_regs(struct cy8ctmg110 *tsc, unsigned char reg,
        unsigned char len, unsigned char *value)
{
    struct i2c_client *client = tsc->client;
    int ret;
    unsigned char i2c_data[6];

    BUG_ON(len > 5);

    i2c_data[0] = reg;
    memcpy(i2c_data + 1, value, len);

    ret = i2c_master_send(client, i2c_data, len + 1);
    if (ret != len + 1) {
        dev_err(&client->dev, "i2c write data cmd failed\n");
        return ret < 0 ? ret : -EIO;
    }

    return 0;
}

static int cy8ctmg110_read_regs(struct cy8ctmg110 *tsc,
        unsigned char *data, unsigned char len, unsigned char cmd)
{
    struct i2c_client *client = tsc->client;
    int ret;
    struct i2c_msg msg[2] = {
        /* first write slave position to i2c devices */
        { client->addr, 0, 1, &cmd },
        /* Second read data from position */
        { client->addr, I2C_M_RD, len, data }
    };

    ret = i2c_transfer(client->adapter, msg, 2);
    if (ret < 0)
        return ret;

    return 0;
}

static int cy8ctmg110_touch_pos(struct cy8ctmg110 *tsc)
{
    struct input_dev *input = tsc->input;
    unsigned char reg_p[CY8CTMG110_REG_MAX];
    int x, y;

    memset(reg_p, 0, CY8CTMG110_REG_MAX);

    /* Reading coordinates */
    if (cy8ctmg110_read_regs(tsc, reg_p, 9, CY8CTMG110_TOUCH_X1) != 0)
        return -EIO;

    y = reg_p[2] << 8 | reg_p[3];
    x = reg_p[0] << 8 | reg_p[1];

    /* Number of touch */
    if (reg_p[8] == 0) {
        input_report_key(input, BTN_TOUCH, 0);
    } else  {
        input_report_key(input, BTN_TOUCH, 1);
        input_report_abs(input, ABS_X, x);
        input_report_abs(input, ABS_Y, y);
    }

    input_sync(input);

    return 0;
}

static int cy8ctmg110_set_sleepmode(struct cy8ctmg110 *ts, bool sleep)
{
    unsigned char reg_p[3];

    if (sleep) {
        reg_p[0] = 0x00;
        reg_p[1] = 0xff;
        reg_p[2] = 5;
    } else {
        reg_p[0] = 0x10;
        reg_p[1] = 0xff;
        reg_p[2] = 0;
    }

    return cy8ctmg110_write_regs(ts, CY8CTMG110_TOUCH_WAKEUP_TIME, 3, reg_p);
}

static irqreturn_t cy8ctmg110_irq_thread(int irq, void *dev_id)
{
    struct cy8ctmg110 *tsc = dev_id;

    cy8ctmg110_touch_pos(tsc);

    return IRQ_HANDLED;
}

static int __devinit cy8ctmg110_probe(struct i2c_client *client,
                    const struct i2c_device_id *id)
{
    const struct cy8ctmg110_pdata *pdata = client->dev.platform_data;
    struct cy8ctmg110 *ts;
    struct input_dev *input_dev;
    int err;

    /* No pdata no way forward */
    if (pdata == NULL) {
        dev_err(&client->dev, "no pdata\n");
        return -ENODEV;
    }

    if (!i2c_check_functionality(client->adapter,
                    I2C_FUNC_SMBUS_READ_WORD_DATA))
        return -EIO;

    ts = kzalloc(sizeof(struct cy8ctmg110), GFP_KERNEL);
    input_dev = input_allocate_device();
    if (!ts || !input_dev) {
        err = -ENOMEM;
        goto err_free_mem;
    }

    ts->client = client;
    ts->input = input_dev;
    ts->reset_pin = pdata->reset_pin;
    ts->irq_pin = pdata->irq_pin;

    snprintf(ts->phys, sizeof(ts->phys),
         "%s/input0", dev_name(&client->dev));

    input_dev->name = CY8CTMG110_DRIVER_NAME " Touchscreen";
    input_dev->phys = ts->phys;
    input_dev->id.bustype = BUS_I2C;
    input_dev->dev.parent = &client->dev;

    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,
            CY8CTMG110_X_MIN, CY8CTMG110_X_MAX, 4, 0);
    input_set_abs_params(input_dev, ABS_Y,
            CY8CTMG110_Y_MIN, CY8CTMG110_Y_MAX, 4, 0);

    if (ts->reset_pin) {
        err = gpio_request(ts->reset_pin, NULL);
        if (err) {
            dev_err(&client->dev,
                "Unable to request GPIO pin %d.\n",
                ts->reset_pin);
            goto err_free_mem;
        }
    }

    cy8ctmg110_power(ts, true);
    cy8ctmg110_set_sleepmode(ts, false);

    err = gpio_request(ts->irq_pin, "touch_irq_key");
    if (err < 0) {
        dev_err(&client->dev,
            "Failed to request GPIO %d, error %d\n",
            ts->irq_pin, err);
        goto err_shutoff_device;
    }

    err = gpio_direction_input(ts->irq_pin);
    if (err < 0) {
        dev_err(&client->dev,
            "Failed to configure input direction for GPIO %d, error %d\n",
            ts->irq_pin, err);
        goto err_free_irq_gpio;
    }

    client->irq = gpio_to_irq(ts->irq_pin);
    if (client->irq < 0) {
        err = client->irq;
        dev_err(&client->dev,
            "Unable to get irq number for GPIO %d, error %d\n",
            ts->irq_pin, err);
        goto err_free_irq_gpio;
    }

    err = request_threaded_irq(client->irq, NULL, cy8ctmg110_irq_thread,
                   IRQF_TRIGGER_RISING | IRQF_ONESHOT,
                   "touch_reset_key", ts);
    if (err < 0) {
        dev_err(&client->dev,
            "irq %d busy? error %d\n", client->irq, err);
        goto err_free_irq_gpio;
    }

    err = input_register_device(input_dev);
    if (err)
        goto err_free_irq;

    i2c_set_clientdata(client, ts);
    device_init_wakeup(&client->dev, 1);
    return 0;

err_free_irq:
    free_irq(client->irq, ts);
err_free_irq_gpio:
    gpio_free(ts->irq_pin);
err_shutoff_device:
    cy8ctmg110_set_sleepmode(ts, true);
    cy8ctmg110_power(ts, false);
    if (ts->reset_pin)
        gpio_free(ts->reset_pin);
err_free_mem:
    input_free_device(input_dev);
    kfree(ts);
    return err;
}

#ifdef CONFIG_PM
static int cy8ctmg110_suspend(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct cy8ctmg110 *ts = i2c_get_clientdata(client);

    if (device_may_wakeup(&client->dev))
        enable_irq_wake(client->irq);
    else {
        cy8ctmg110_set_sleepmode(ts, true);
        cy8ctmg110_power(ts, false);
    }
    return 0;
}

static int cy8ctmg110_resume(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct cy8ctmg110 *ts = i2c_get_clientdata(client);

    if (device_may_wakeup(&client->dev))
        disable_irq_wake(client->irq);
    else {
        cy8ctmg110_power(ts, true);
        cy8ctmg110_set_sleepmode(ts, false);
    }
    return 0;
}

static SIMPLE_DEV_PM_OPS(cy8ctmg110_pm, cy8ctmg110_suspend, cy8ctmg110_resume);
#endif

static int __devexit cy8ctmg110_remove(struct i2c_client *client)
{
    struct cy8ctmg110 *ts = i2c_get_clientdata(client);

    cy8ctmg110_set_sleepmode(ts, true);
    cy8ctmg110_power(ts, false);

    free_irq(client->irq, ts);
    input_unregister_device(ts->input);
    gpio_free(ts->irq_pin);
    if (ts->reset_pin)
        gpio_free(ts->reset_pin);
    kfree(ts);

    return 0;
}

static const struct i2c_device_id cy8ctmg110_idtable[] = {
    { CY8CTMG110_DRIVER_NAME, 1 },
    { }
};

MODULE_DEVICE_TABLE(i2c, cy8ctmg110_idtable);

static struct i2c_driver cy8ctmg110_driver = {
    .driver     = {
        .owner  = THIS_MODULE,
        .name   = CY8CTMG110_DRIVER_NAME,
#ifdef CONFIG_PM
        .pm = &cy8ctmg110_pm,
#endif
    },
    .id_table   = cy8ctmg110_idtable,
    .probe      = cy8ctmg110_probe,
    .remove     = __devexit_p(cy8ctmg110_remove),
};

module_i2c_driver(cy8ctmg110_driver);

MODULE_AUTHOR("Samuli Konttila <[email protected]>");
MODULE_DESCRIPTION("cy8ctmg110 TouchScreen Driver");
MODULE_LICENSE("GPL v2");