mms114.c

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/*
 * Copyright (C) 2012 Samsung Electronics Co.Ltd
 * Author: Joonyoung Shim <[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.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/i2c/mms114.h>
#include <linux/input/mt.h>
#include <linux/interrupt.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>

/* Write only registers */
#define MMS114_MODE_CONTROL     0x01
#define MMS114_OPERATION_MODE_MASK  0xE
#define MMS114_ACTIVE           (1 << 1)

#define MMS114_XY_RESOLUTION_H      0x02
#define MMS114_X_RESOLUTION     0x03
#define MMS114_Y_RESOLUTION     0x04
#define MMS114_CONTACT_THRESHOLD    0x05
#define MMS114_MOVING_THRESHOLD     0x06

/* Read only registers */
#define MMS114_PACKET_SIZE      0x0F
#define MMS114_INFOMATION       0x10
#define MMS114_TSP_REV          0xF0

/* Minimum delay time is 50us between stop and start signal of i2c */
#define MMS114_I2C_DELAY        50

/* 200ms needs after power on */
#define MMS114_POWERON_DELAY        200

/* Touchscreen absolute values */
#define MMS114_MAX_AREA         0xff

#define MMS114_MAX_TOUCH        10
#define MMS114_PACKET_NUM       8

/* Touch type */
#define MMS114_TYPE_NONE        0
#define MMS114_TYPE_TOUCHSCREEN     1
#define MMS114_TYPE_TOUCHKEY        2

struct mms114_data {
    struct i2c_client   *client;
    struct input_dev    *input_dev;
    struct regulator    *core_reg;
    struct regulator    *io_reg;
    const struct mms114_platform_data   *pdata;

    /* Use cache data for mode control register(write only) */
    u8          cache_mode_control;
};

struct mms114_touch {
    u8 id:4, reserved_bit4:1, type:2, pressed:1;
    u8 x_hi:4, y_hi:4;
    u8 x_lo;
    u8 y_lo;
    u8 width;
    u8 strength;
    u8 reserved[2];
} __packed;

static int __mms114_read_reg(struct mms114_data *data, unsigned int reg,
                 unsigned int len, u8 *val)
{
    struct i2c_client *client = data->client;
    struct i2c_msg xfer[2];
    u8 buf = reg & 0xff;
    int error;

    if (reg <= MMS114_MODE_CONTROL && reg + len > MMS114_MODE_CONTROL)
        BUG();

    /* Write register: use repeated start */
    xfer[0].addr = client->addr;
    xfer[0].flags = I2C_M_TEN | I2C_M_NOSTART;
    xfer[0].len = 1;
    xfer[0].buf = &buf;

    /* Read data */
    xfer[1].addr = client->addr;
    xfer[1].flags = I2C_M_RD;
    xfer[1].len = len;
    xfer[1].buf = val;

    error = i2c_transfer(client->adapter, xfer, 2);
    if (error != 2) {
        dev_err(&client->dev,
            "%s: i2c transfer failed (%d)\n", __func__, error);
        return error < 0 ? error : -EIO;
    }
    udelay(MMS114_I2C_DELAY);

    return 0;
}

static int mms114_read_reg(struct mms114_data *data, unsigned int reg)
{
    u8 val;
    int error;

    if (reg == MMS114_MODE_CONTROL)
        return data->cache_mode_control;

    error = __mms114_read_reg(data, reg, 1, &val);
    return error < 0 ? error : val;
}

static int mms114_write_reg(struct mms114_data *data, unsigned int reg,
                unsigned int val)
{
    struct i2c_client *client = data->client;
    u8 buf[2];
    int error;

    buf[0] = reg & 0xff;
    buf[1] = val & 0xff;

    error = i2c_master_send(client, buf, 2);
    if (error != 2) {
        dev_err(&client->dev,
            "%s: i2c send failed (%d)\n", __func__, error);
        return error < 0 ? error : -EIO;
    }
    udelay(MMS114_I2C_DELAY);

    if (reg == MMS114_MODE_CONTROL)
        data->cache_mode_control = val;

    return 0;
}

static void mms114_process_mt(struct mms114_data *data, struct mms114_touch *touch)
{
    const struct mms114_platform_data *pdata = data->pdata;
    struct i2c_client *client = data->client;
    struct input_dev *input_dev = data->input_dev;
    unsigned int id;
    unsigned int x;
    unsigned int y;

    if (touch->id > MMS114_MAX_TOUCH) {
        dev_err(&client->dev, "Wrong touch id (%d)\n", touch->id);
        return;
    }

    if (touch->type != MMS114_TYPE_TOUCHSCREEN) {
        dev_err(&client->dev, "Wrong touch type (%d)\n", touch->type);
        return;
    }

    id = touch->id - 1;
    x = touch->x_lo | touch->x_hi << 8;
    y = touch->y_lo | touch->y_hi << 8;
    if (x > pdata->x_size || y > pdata->y_size) {
        dev_dbg(&client->dev,
            "Wrong touch coordinates (%d, %d)\n", x, y);
        return;
    }

    if (pdata->x_invert)
        x = pdata->x_size - x;
    if (pdata->y_invert)
        y = pdata->y_size - y;

    dev_dbg(&client->dev,
        "id: %d, type: %d, pressed: %d, x: %d, y: %d, width: %d, strength: %d\n",
        id, touch->type, touch->pressed,
        x, y, touch->width, touch->strength);

    input_mt_slot(input_dev, id);
    input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, touch->pressed);

    if (touch->pressed) {
        input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, touch->width);
        input_report_abs(input_dev, ABS_MT_POSITION_X, x);
        input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
        input_report_abs(input_dev, ABS_MT_PRESSURE, touch->strength);
    }
}

static irqreturn_t mms114_interrupt(int irq, void *dev_id)
{
    struct mms114_data *data = dev_id;
    struct input_dev *input_dev = data->input_dev;
    struct mms114_touch touch[MMS114_MAX_TOUCH];
    int packet_size;
    int touch_size;
    int index;
    int error;

    mutex_lock(&input_dev->mutex);
    if (!input_dev->users) {
        mutex_unlock(&input_dev->mutex);
        goto out;
    }
    mutex_unlock(&input_dev->mutex);

    packet_size = mms114_read_reg(data, MMS114_PACKET_SIZE);
    if (packet_size <= 0)
        goto out;

    touch_size = packet_size / MMS114_PACKET_NUM;

    error = __mms114_read_reg(data, MMS114_INFOMATION, packet_size,
            (u8 *)touch);
    if (error < 0)
        goto out;

    for (index = 0; index < touch_size; index++)
        mms114_process_mt(data, touch + index);

    input_mt_report_pointer_emulation(data->input_dev, true);
    input_sync(data->input_dev);

out:
    return IRQ_HANDLED;
}

static int mms114_set_active(struct mms114_data *data, bool active)
{
    int val;

    val = mms114_read_reg(data, MMS114_MODE_CONTROL);
    if (val < 0)
        return val;

    val &= ~MMS114_OPERATION_MODE_MASK;

    /* If active is false, sleep mode */
    if (active)
        val |= MMS114_ACTIVE;

    return mms114_write_reg(data, MMS114_MODE_CONTROL, val);
}

static int mms114_get_version(struct mms114_data *data)
{
    struct device *dev = &data->client->dev;
    u8 buf[6];
    int error;

    error = __mms114_read_reg(data, MMS114_TSP_REV, 6, buf);
    if (error < 0)
        return error;

    dev_info(dev, "TSP Rev: 0x%x, HW Rev: 0x%x, Firmware Ver: 0x%x\n",
         buf[0], buf[1], buf[3]);

    return 0;
}

static int mms114_setup_regs(struct mms114_data *data)
{
    const struct mms114_platform_data *pdata = data->pdata;
    int val;
    int error;

    error = mms114_get_version(data);
    if (error < 0)
        return error;

    error = mms114_set_active(data, true);
    if (error < 0)
        return error;

    val = (pdata->x_size >> 8) & 0xf;
    val |= ((pdata->y_size >> 8) & 0xf) << 4;
    error = mms114_write_reg(data, MMS114_XY_RESOLUTION_H, val);
    if (error < 0)
        return error;

    val = pdata->x_size & 0xff;
    error = mms114_write_reg(data, MMS114_X_RESOLUTION, val);
    if (error < 0)
        return error;

    val = pdata->y_size & 0xff;
    error = mms114_write_reg(data, MMS114_Y_RESOLUTION, val);
    if (error < 0)
        return error;

    if (pdata->contact_threshold) {
        error = mms114_write_reg(data, MMS114_CONTACT_THRESHOLD,
                pdata->contact_threshold);
        if (error < 0)
            return error;
    }

    if (pdata->moving_threshold) {
        error = mms114_write_reg(data, MMS114_MOVING_THRESHOLD,
                pdata->moving_threshold);
        if (error < 0)
            return error;
    }

    return 0;
}

static int mms114_start(struct mms114_data *data)
{
    struct i2c_client *client = data->client;
    int error;

    if (data->core_reg)
        regulator_enable(data->core_reg);
    if (data->io_reg)
        regulator_enable(data->io_reg);
    mdelay(MMS114_POWERON_DELAY);

    error = mms114_setup_regs(data);
    if (error < 0)
        return error;

    if (data->pdata->cfg_pin)
        data->pdata->cfg_pin(true);

    enable_irq(client->irq);

    return 0;
}

static void mms114_stop(struct mms114_data *data)
{
    struct i2c_client *client = data->client;

    disable_irq(client->irq);

    if (data->pdata->cfg_pin)
        data->pdata->cfg_pin(false);

    if (data->io_reg)
        regulator_disable(data->io_reg);
    if (data->core_reg)
        regulator_disable(data->core_reg);
}

static int mms114_input_open(struct input_dev *dev)
{
    struct mms114_data *data = input_get_drvdata(dev);

    return mms114_start(data);
}

static void mms114_input_close(struct input_dev *dev)
{
    struct mms114_data *data = input_get_drvdata(dev);

    mms114_stop(data);
}

static int __devinit mms114_probe(struct i2c_client *client,
                  const struct i2c_device_id *id)
{
    struct mms114_data *data;
    struct input_dev *input_dev;
    int error;

    if (!client->dev.platform_data) {
        dev_err(&client->dev, "Need platform data\n");
        return -EINVAL;
    }

    if (!i2c_check_functionality(client->adapter,
                I2C_FUNC_PROTOCOL_MANGLING)) {
        dev_err(&client->dev,
            "Need i2c bus that supports protocol mangling\n");
        return -ENODEV;
    }

    data = kzalloc(sizeof(struct mms114_data), GFP_KERNEL);
    input_dev = input_allocate_device();
    if (!data || !input_dev) {
        dev_err(&client->dev, "Failed to allocate memory\n");
        error = -ENOMEM;
        goto err_free_mem;
    }

    data->client = client;
    data->input_dev = input_dev;
    data->pdata = client->dev.platform_data;

    input_dev->name = "MELPAS MMS114 Touchscreen";
    input_dev->id.bustype = BUS_I2C;
    input_dev->dev.parent = &client->dev;
    input_dev->open = mms114_input_open;
    input_dev->close = mms114_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, data->pdata->x_size, 0, 0);
    input_set_abs_params(input_dev, ABS_Y, 0, data->pdata->y_size, 0, 0);

    /* For multi touch */
    input_mt_init_slots(input_dev, MMS114_MAX_TOUCH, 0);
    input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
                 0, MMS114_MAX_AREA, 0, 0);
    input_set_abs_params(input_dev, ABS_MT_POSITION_X,
                 0, data->pdata->x_size, 0, 0);
    input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
                 0, data->pdata->y_size, 0, 0);
    input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 255, 0, 0);

    input_set_drvdata(input_dev, data);
    i2c_set_clientdata(client, data);

    data->core_reg = regulator_get(&client->dev, "avdd");
    if (IS_ERR(data->core_reg)) {
        error = PTR_ERR(data->core_reg);
        dev_err(&client->dev,
            "Unable to get the Core regulator (%d)\n", error);
        goto err_free_mem;
    }

    data->io_reg = regulator_get(&client->dev, "vdd");
    if (IS_ERR(data->io_reg)) {
        error = PTR_ERR(data->io_reg);
        dev_err(&client->dev,
            "Unable to get the IO regulator (%d)\n", error);
        goto err_core_reg;
    }

    error = request_threaded_irq(client->irq, NULL, mms114_interrupt,
            IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "mms114", data);
    if (error) {
        dev_err(&client->dev, "Failed to register interrupt\n");
        goto err_io_reg;
    }
    disable_irq(client->irq);

    error = input_register_device(data->input_dev);
    if (error)
        goto err_free_irq;

    return 0;

err_free_irq:
    free_irq(client->irq, data);
err_io_reg:
    regulator_put(data->io_reg);
err_core_reg:
    regulator_put(data->core_reg);
err_free_mem:
    input_free_device(input_dev);
    kfree(data);
    return error;
}

static int __devexit mms114_remove(struct i2c_client *client)
{
    struct mms114_data *data = i2c_get_clientdata(client);

    free_irq(client->irq, data);
    regulator_put(data->io_reg);
    regulator_put(data->core_reg);
    input_unregister_device(data->input_dev);
    kfree(data);

    return 0;
}

#ifdef CONFIG_PM_SLEEP
static int mms114_suspend(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct mms114_data *data = i2c_get_clientdata(client);
    struct input_dev *input_dev = data->input_dev;
    int id;

    /* Release all touch */
    for (id = 0; id < MMS114_MAX_TOUCH; id++) {
        input_mt_slot(input_dev, id);
        input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, false);
    }

    input_mt_report_pointer_emulation(input_dev, true);
    input_sync(input_dev);

    mutex_lock(&input_dev->mutex);
    if (input_dev->users)
        mms114_stop(data);
    mutex_unlock(&input_dev->mutex);

    return 0;
}

static int mms114_resume(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct mms114_data *data = i2c_get_clientdata(client);
    struct input_dev *input_dev = data->input_dev;
    int error;

    mutex_lock(&input_dev->mutex);
    if (input_dev->users) {
        error = mms114_start(data);
        if (error < 0) {
            mutex_unlock(&input_dev->mutex);
            return error;
        }
    }
    mutex_unlock(&input_dev->mutex);

    return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(mms114_pm_ops, mms114_suspend, mms114_resume);

static const struct i2c_device_id mms114_id[] = {
    { "mms114", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, mms114_id);

static struct i2c_driver mms114_driver = {
    .driver = {
        .name   = "mms114",
        .owner  = THIS_MODULE,
        .pm = &mms114_pm_ops,
    },
    .probe      = mms114_probe,
    .remove     = __devexit_p(mms114_remove),
    .id_table   = mms114_id,
};

module_i2c_driver(mms114_driver);

/* Module information */
MODULE_AUTHOR("Joonyoung Shim <[email protected]>");
MODULE_DESCRIPTION("MELFAS mms114 Touchscreen driver");
MODULE_LICENSE("GPL");