max7359_keypad.c

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/*
 * max7359_keypad.c - MAX7359 Key Switch Controller Driver
 *
 * Copyright (C) 2009 Samsung Electronics
 * Kim Kyuwon <[email protected]>
 *
 * Based on pxa27x_keypad.c
 *
 * 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.
 *
 * Datasheet: http://www.maxim-ic.com/quick_view2.cfm/qv_pk/5456
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/pm.h>
#include <linux/input.h>
#include <linux/input/matrix_keypad.h>

#define MAX7359_MAX_KEY_ROWS    8
#define MAX7359_MAX_KEY_COLS    8
#define MAX7359_MAX_KEY_NUM (MAX7359_MAX_KEY_ROWS * MAX7359_MAX_KEY_COLS)
#define MAX7359_ROW_SHIFT   3

/*
 * MAX7359 registers
 */
#define MAX7359_REG_KEYFIFO 0x00
#define MAX7359_REG_CONFIG  0x01
#define MAX7359_REG_DEBOUNCE    0x02
#define MAX7359_REG_INTERRUPT   0x03
#define MAX7359_REG_PORTS   0x04
#define MAX7359_REG_KEYREP  0x05
#define MAX7359_REG_SLEEP   0x06

/*
 * Configuration register bits
 */
#define MAX7359_CFG_SLEEP   (1 << 7)
#define MAX7359_CFG_INTERRUPT   (1 << 5)
#define MAX7359_CFG_KEY_RELEASE (1 << 3)
#define MAX7359_CFG_WAKEUP  (1 << 1)
#define MAX7359_CFG_TIMEOUT (1 << 0)

/*
 * Autosleep register values (ms)
 */
#define MAX7359_AUTOSLEEP_8192  0x01
#define MAX7359_AUTOSLEEP_4096  0x02
#define MAX7359_AUTOSLEEP_2048  0x03
#define MAX7359_AUTOSLEEP_1024  0x04
#define MAX7359_AUTOSLEEP_512   0x05
#define MAX7359_AUTOSLEEP_256   0x06

struct max7359_keypad {
    /* matrix key code map */
    unsigned short keycodes[MAX7359_MAX_KEY_NUM];

    struct input_dev *input_dev;
    struct i2c_client *client;
};

static int max7359_write_reg(struct i2c_client *client, u8 reg, u8 val)
{
    int ret = i2c_smbus_write_byte_data(client, reg, val);

    if (ret < 0)
        dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
            __func__, reg, val, ret);
    return ret;
}

static int max7359_read_reg(struct i2c_client *client, int reg)
{
    int ret = i2c_smbus_read_byte_data(client, reg);

    if (ret < 0)
        dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
            __func__, reg, ret);
    return ret;
}

static void max7359_build_keycode(struct max7359_keypad *keypad,
                const struct matrix_keymap_data *keymap_data)
{
    struct input_dev *input_dev = keypad->input_dev;
    int i;

    for (i = 0; i < keymap_data->keymap_size; i++) {
        unsigned int key = keymap_data->keymap[i];
        unsigned int row = KEY_ROW(key);
        unsigned int col = KEY_COL(key);
        unsigned int scancode = MATRIX_SCAN_CODE(row, col,
                        MAX7359_ROW_SHIFT);
        unsigned short keycode = KEY_VAL(key);

        keypad->keycodes[scancode] = keycode;
        __set_bit(keycode, input_dev->keybit);
    }
    __clear_bit(KEY_RESERVED, input_dev->keybit);
}

/* runs in an IRQ thread -- can (and will!) sleep */
static irqreturn_t max7359_interrupt(int irq, void *dev_id)
{
    struct max7359_keypad *keypad = dev_id;
    struct input_dev *input_dev = keypad->input_dev;
    int val, row, col, release, code;

    val = max7359_read_reg(keypad->client, MAX7359_REG_KEYFIFO);
    row = val & 0x7;
    col = (val >> 3) & 0x7;
    release = val & 0x40;

    code = MATRIX_SCAN_CODE(row, col, MAX7359_ROW_SHIFT);

    dev_dbg(&keypad->client->dev,
        "key[%d:%d] %s\n", row, col, release ? "release" : "press");

    input_event(input_dev, EV_MSC, MSC_SCAN, code);
    input_report_key(input_dev, keypad->keycodes[code], !release);
    input_sync(input_dev);

    return IRQ_HANDLED;
}

/*
 * Let MAX7359 fall into a deep sleep:
 * If no keys are pressed, enter sleep mode for 8192 ms. And if any
 * key is pressed, the MAX7359 returns to normal operating mode.
 */
static inline void max7359_fall_deepsleep(struct i2c_client *client)
{
    max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_8192);
}

/*
 * Let MAX7359 take a catnap:
 * Autosleep just for 256 ms.
 */
static inline void max7359_take_catnap(struct i2c_client *client)
{
    max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_256);
}

static int max7359_open(struct input_dev *dev)
{
    struct max7359_keypad *keypad = input_get_drvdata(dev);

    max7359_take_catnap(keypad->client);

    return 0;
}

static void max7359_close(struct input_dev *dev)
{
    struct max7359_keypad *keypad = input_get_drvdata(dev);

    max7359_fall_deepsleep(keypad->client);
}

static void max7359_initialize(struct i2c_client *client)
{
    max7359_write_reg(client, MAX7359_REG_CONFIG,
        MAX7359_CFG_INTERRUPT | /* Irq clears after host read */
        MAX7359_CFG_KEY_RELEASE | /* Key release enable */
        MAX7359_CFG_WAKEUP); /* Key press wakeup enable */

    /* Full key-scan functionality */
    max7359_write_reg(client, MAX7359_REG_DEBOUNCE, 0x1F);

    /* nINT asserts every debounce cycles */
    max7359_write_reg(client, MAX7359_REG_INTERRUPT, 0x01);

    max7359_fall_deepsleep(client);
}

static int __devinit max7359_probe(struct i2c_client *client,
                    const struct i2c_device_id *id)
{
    const struct matrix_keymap_data *keymap_data = client->dev.platform_data;
    struct max7359_keypad *keypad;
    struct input_dev *input_dev;
    int ret;
    int error;

    if (!client->irq) {
        dev_err(&client->dev, "The irq number should not be zero\n");
        return -EINVAL;
    }

    /* Detect MAX7359: The initial Keys FIFO value is '0x3F' */
    ret = max7359_read_reg(client, MAX7359_REG_KEYFIFO);
    if (ret < 0) {
        dev_err(&client->dev, "failed to detect device\n");
        return -ENODEV;
    }

    dev_dbg(&client->dev, "keys FIFO is 0x%02x\n", ret);

    keypad = kzalloc(sizeof(struct max7359_keypad), GFP_KERNEL);
    input_dev = input_allocate_device();
    if (!keypad || !input_dev) {
        dev_err(&client->dev, "failed to allocate memory\n");
        error = -ENOMEM;
        goto failed_free_mem;
    }

    keypad->client = client;
    keypad->input_dev = input_dev;

    input_dev->name = client->name;
    input_dev->id.bustype = BUS_I2C;
    input_dev->open = max7359_open;
    input_dev->close = max7359_close;
    input_dev->dev.parent = &client->dev;

    input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
    input_dev->keycodesize = sizeof(keypad->keycodes[0]);
    input_dev->keycodemax = ARRAY_SIZE(keypad->keycodes);
    input_dev->keycode = keypad->keycodes;

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

    max7359_build_keycode(keypad, keymap_data);

    error = request_threaded_irq(client->irq, NULL, max7359_interrupt,
                     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
                     client->name, keypad);
    if (error) {
        dev_err(&client->dev, "failed to register interrupt\n");
        goto failed_free_mem;
    }

    /* Register the input device */
    error = input_register_device(input_dev);
    if (error) {
        dev_err(&client->dev, "failed to register input device\n");
        goto failed_free_irq;
    }

    /* Initialize MAX7359 */
    max7359_initialize(client);

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

    return 0;

failed_free_irq:
    free_irq(client->irq, keypad);
failed_free_mem:
    input_free_device(input_dev);
    kfree(keypad);
    return error;
}

static int __devexit max7359_remove(struct i2c_client *client)
{
    struct max7359_keypad *keypad = i2c_get_clientdata(client);

    free_irq(client->irq, keypad);
    input_unregister_device(keypad->input_dev);
    kfree(keypad);

    return 0;
}

#ifdef CONFIG_PM
static int max7359_suspend(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);

    max7359_fall_deepsleep(client);

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

    return 0;
}

static int max7359_resume(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);

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

    /* Restore the default setting */
    max7359_take_catnap(client);

    return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(max7359_pm, max7359_suspend, max7359_resume);

static const struct i2c_device_id max7359_ids[] = {
    { "max7359", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, max7359_ids);

static struct i2c_driver max7359_i2c_driver = {
    .driver = {
        .name = "max7359",
        .pm   = &max7359_pm,
    },
    .probe      = max7359_probe,
    .remove     = __devexit_p(max7359_remove),
    .id_table   = max7359_ids,
};

module_i2c_driver(max7359_i2c_driver);

MODULE_AUTHOR("Kim Kyuwon <[email protected]>");
MODULE_DESCRIPTION("MAX7359 Key Switch Controller Driver");
MODULE_LICENSE("GPL v2");