mcs_touchkey.c

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/*
 * Touchkey driver for MELFAS MCS5000/5080 controller
 *
 * Copyright (C) 2010 Samsung Electronics Co.Ltd
 * Author: HeungJun Kim <[email protected]>
 * 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 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/init.h>
#include <linux/i2c.h>
#include <linux/i2c/mcs.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/irq.h>
#include <linux/slab.h>
#include <linux/pm.h>

/* MCS5000 Touchkey */
#define MCS5000_TOUCHKEY_STATUS     0x04
#define MCS5000_TOUCHKEY_STATUS_PRESS   7
#define MCS5000_TOUCHKEY_FW     0x0a
#define MCS5000_TOUCHKEY_BASE_VAL   0x61

/* MCS5080 Touchkey */
#define MCS5080_TOUCHKEY_STATUS     0x00
#define MCS5080_TOUCHKEY_STATUS_PRESS   3
#define MCS5080_TOUCHKEY_FW     0x01
#define MCS5080_TOUCHKEY_BASE_VAL   0x1

enum mcs_touchkey_type {
    MCS5000_TOUCHKEY,
    MCS5080_TOUCHKEY,
};

struct mcs_touchkey_chip {
    unsigned int status_reg;
    unsigned int pressbit;
    unsigned int press_invert;
    unsigned int baseval;
};

struct mcs_touchkey_data {
    void (*poweron)(bool);

    struct i2c_client *client;
    struct input_dev *input_dev;
    struct mcs_touchkey_chip chip;
    unsigned int key_code;
    unsigned int key_val;
    unsigned short keycodes[];
};

static irqreturn_t mcs_touchkey_interrupt(int irq, void *dev_id)
{
    struct mcs_touchkey_data *data = dev_id;
    struct mcs_touchkey_chip *chip = &data->chip;
    struct i2c_client *client = data->client;
    struct input_dev *input = data->input_dev;
    unsigned int key_val;
    unsigned int pressed;
    int val;

    val = i2c_smbus_read_byte_data(client, chip->status_reg);
    if (val < 0) {
        dev_err(&client->dev, "i2c read error [%d]\n", val);
        goto out;
    }

    pressed = (val & (1 << chip->pressbit)) >> chip->pressbit;
    if (chip->press_invert)
        pressed ^= chip->press_invert;

    /* key_val is 0 when released, so we should use key_val of press. */
    if (pressed) {
        key_val = val & (0xff >> (8 - chip->pressbit));
        if (!key_val)
            goto out;
        key_val -= chip->baseval;
        data->key_code = data->keycodes[key_val];
        data->key_val = key_val;
    }

    input_event(input, EV_MSC, MSC_SCAN, data->key_val);
    input_report_key(input, data->key_code, pressed);
    input_sync(input);

    dev_dbg(&client->dev, "key %d %d %s\n", data->key_val, data->key_code,
        pressed ? "pressed" : "released");

 out:
    return IRQ_HANDLED;
}

static int __devinit mcs_touchkey_probe(struct i2c_client *client,
        const struct i2c_device_id *id)
{
    const struct mcs_platform_data *pdata;
    struct mcs_touchkey_data *data;
    struct input_dev *input_dev;
    unsigned int fw_reg;
    int fw_ver;
    int error;
    int i;

    pdata = client->dev.platform_data;
    if (!pdata) {
        dev_err(&client->dev, "no platform data defined\n");
        return -EINVAL;
    }

    data = kzalloc(sizeof(struct mcs_touchkey_data) +
            sizeof(data->keycodes[0]) * (pdata->key_maxval + 1),
            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;

    if (id->driver_data == MCS5000_TOUCHKEY) {
        data->chip.status_reg = MCS5000_TOUCHKEY_STATUS;
        data->chip.pressbit = MCS5000_TOUCHKEY_STATUS_PRESS;
        data->chip.baseval = MCS5000_TOUCHKEY_BASE_VAL;
        fw_reg = MCS5000_TOUCHKEY_FW;
    } else {
        data->chip.status_reg = MCS5080_TOUCHKEY_STATUS;
        data->chip.pressbit = MCS5080_TOUCHKEY_STATUS_PRESS;
        data->chip.press_invert = 1;
        data->chip.baseval = MCS5080_TOUCHKEY_BASE_VAL;
        fw_reg = MCS5080_TOUCHKEY_FW;
    }

    fw_ver = i2c_smbus_read_byte_data(client, fw_reg);
    if (fw_ver < 0) {
        error = fw_ver;
        dev_err(&client->dev, "i2c read error[%d]\n", error);
        goto err_free_mem;
    }
    dev_info(&client->dev, "Firmware version: %d\n", fw_ver);

    input_dev->name = "MELPAS MCS Touchkey";
    input_dev->id.bustype = BUS_I2C;
    input_dev->dev.parent = &client->dev;
    input_dev->evbit[0] = BIT_MASK(EV_KEY);
    if (!pdata->no_autorepeat)
        input_dev->evbit[0] |= BIT_MASK(EV_REP);
    input_dev->keycode = data->keycodes;
    input_dev->keycodesize = sizeof(data->keycodes[0]);
    input_dev->keycodemax = pdata->key_maxval + 1;

    for (i = 0; i < pdata->keymap_size; i++) {
        unsigned int val = MCS_KEY_VAL(pdata->keymap[i]);
        unsigned int code = MCS_KEY_CODE(pdata->keymap[i]);

        data->keycodes[val] = code;
        __set_bit(code, input_dev->keybit);
    }

    input_set_capability(input_dev, EV_MSC, MSC_SCAN);
    input_set_drvdata(input_dev, data);

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

    if (pdata->poweron) {
        data->poweron = pdata->poweron;
        data->poweron(true);
    }

    error = request_threaded_irq(client->irq, NULL, mcs_touchkey_interrupt,
                     IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
                     client->dev.driver->name, data);
    if (error) {
        dev_err(&client->dev, "Failed to register interrupt\n");
        goto err_free_mem;
    }

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

    i2c_set_clientdata(client, data);
    return 0;

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

static int __devexit mcs_touchkey_remove(struct i2c_client *client)
{
    struct mcs_touchkey_data *data = i2c_get_clientdata(client);

    free_irq(client->irq, data);
    if (data->poweron)
        data->poweron(false);
    input_unregister_device(data->input_dev);
    kfree(data);

    return 0;
}

static void mcs_touchkey_shutdown(struct i2c_client *client)
{
    struct mcs_touchkey_data *data = i2c_get_clientdata(client);

    if (data->poweron)
        data->poweron(false);
}

#ifdef CONFIG_PM_SLEEP
static int mcs_touchkey_suspend(struct device *dev)
{
    struct mcs_touchkey_data *data = dev_get_drvdata(dev);
    struct i2c_client *client = data->client;

    /* Disable the work */
    disable_irq(client->irq);

    /* Finally turn off the power */
    if (data->poweron)
        data->poweron(false);

    return 0;
}

static int mcs_touchkey_resume(struct device *dev)
{
    struct mcs_touchkey_data *data = dev_get_drvdata(dev);
    struct i2c_client *client = data->client;

    /* Enable the device first */
    if (data->poweron)
        data->poweron(true);

    /* Enable irq again */
    enable_irq(client->irq);

    return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(mcs_touchkey_pm_ops,
             mcs_touchkey_suspend, mcs_touchkey_resume);

static const struct i2c_device_id mcs_touchkey_id[] = {
    { "mcs5000_touchkey", MCS5000_TOUCHKEY },
    { "mcs5080_touchkey", MCS5080_TOUCHKEY },
    { }
};
MODULE_DEVICE_TABLE(i2c, mcs_touchkey_id);

static struct i2c_driver mcs_touchkey_driver = {
    .driver = {
        .name   = "mcs_touchkey",
        .owner  = THIS_MODULE,
        .pm = &mcs_touchkey_pm_ops,
    },
    .probe      = mcs_touchkey_probe,
    .remove     = __devexit_p(mcs_touchkey_remove),
    .shutdown       = mcs_touchkey_shutdown,
    .id_table   = mcs_touchkey_id,
};

module_i2c_driver(mcs_touchkey_driver);

/* Module information */
MODULE_AUTHOR("Joonyoung Shim <[email protected]>");
MODULE_AUTHOR("HeungJun Kim <[email protected]>");
MODULE_DESCRIPTION("Touchkey driver for MELFAS MCS5000/5080 controller");
MODULE_LICENSE("GPL");