stmpe-keypad.c

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/*
 * Copyright (C) ST-Ericsson SA 2010
 *
 * License Terms: GNU General Public License, version 2
 * Author: Rabin Vincent <[email protected]> for ST-Ericsson
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/input/matrix_keypad.h>
#include <linux/mfd/stmpe.h>

/* These are at the same addresses in all STMPE variants */
#define STMPE_KPC_COL           0x60
#define STMPE_KPC_ROW_MSB       0x61
#define STMPE_KPC_ROW_LSB       0x62
#define STMPE_KPC_CTRL_MSB      0x63
#define STMPE_KPC_CTRL_LSB      0x64
#define STMPE_KPC_COMBI_KEY_0       0x65
#define STMPE_KPC_COMBI_KEY_1       0x66
#define STMPE_KPC_COMBI_KEY_2       0x67
#define STMPE_KPC_DATA_BYTE0        0x68
#define STMPE_KPC_DATA_BYTE1        0x69
#define STMPE_KPC_DATA_BYTE2        0x6a
#define STMPE_KPC_DATA_BYTE3        0x6b
#define STMPE_KPC_DATA_BYTE4        0x6c

#define STMPE_KPC_CTRL_LSB_SCAN     (0x1 << 0)
#define STMPE_KPC_CTRL_LSB_DEBOUNCE (0x7f << 1)
#define STMPE_KPC_CTRL_MSB_SCAN_COUNT   (0xf << 4)

#define STMPE_KPC_ROW_MSB_ROWS      0xff

#define STMPE_KPC_DATA_UP       (0x1 << 7)
#define STMPE_KPC_DATA_ROW      (0xf << 3)
#define STMPE_KPC_DATA_COL      (0x7 << 0)
#define STMPE_KPC_DATA_NOKEY_MASK   0x78

#define STMPE_KEYPAD_MAX_DEBOUNCE   127
#define STMPE_KEYPAD_MAX_SCAN_COUNT 15

#define STMPE_KEYPAD_MAX_ROWS       8
#define STMPE_KEYPAD_MAX_COLS       8
#define STMPE_KEYPAD_ROW_SHIFT      3
#define STMPE_KEYPAD_KEYMAP_SIZE    \
    (STMPE_KEYPAD_MAX_ROWS * STMPE_KEYPAD_MAX_COLS)

struct stmpe_keypad_variant {
    bool        auto_increment;
    int     num_data;
    int     num_normal_data;
    int     max_cols;
    int     max_rows;
    unsigned int    col_gpios;
    unsigned int    row_gpios;
};

static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
    [STMPE1601] = {
        .auto_increment     = true,
        .num_data       = 5,
        .num_normal_data    = 3,
        .max_cols       = 8,
        .max_rows       = 8,
        .col_gpios      = 0x000ff,  /* GPIO 0 - 7 */
        .row_gpios      = 0x0ff00,  /* GPIO 8 - 15 */
    },
    [STMPE2401] = {
        .auto_increment     = false,
        .num_data       = 3,
        .num_normal_data    = 2,
        .max_cols       = 8,
        .max_rows       = 12,
        .col_gpios      = 0x0000ff, /* GPIO 0 - 7*/
        .row_gpios      = 0x1fef00, /* GPIO 8-14, 16-20 */
    },
    [STMPE2403] = {
        .auto_increment     = true,
        .num_data       = 5,
        .num_normal_data    = 3,
        .max_cols       = 8,
        .max_rows       = 12,
        .col_gpios      = 0x0000ff, /* GPIO 0 - 7*/
        .row_gpios      = 0x1fef00, /* GPIO 8-14, 16-20 */
    },
};

struct stmpe_keypad {
    struct stmpe *stmpe;
    struct input_dev *input;
    const struct stmpe_keypad_variant *variant;
    const struct stmpe_keypad_platform_data *plat;

    unsigned int rows;
    unsigned int cols;

    unsigned short keymap[STMPE_KEYPAD_KEYMAP_SIZE];
};

static int stmpe_keypad_read_data(struct stmpe_keypad *keypad, u8 *data)
{
    const struct stmpe_keypad_variant *variant = keypad->variant;
    struct stmpe *stmpe = keypad->stmpe;
    int ret;
    int i;

    if (variant->auto_increment)
        return stmpe_block_read(stmpe, STMPE_KPC_DATA_BYTE0,
                    variant->num_data, data);

    for (i = 0; i < variant->num_data; i++) {
        ret = stmpe_reg_read(stmpe, STMPE_KPC_DATA_BYTE0 + i);
        if (ret < 0)
            return ret;

        data[i] = ret;
    }

    return 0;
}

static irqreturn_t stmpe_keypad_irq(int irq, void *dev)
{
    struct stmpe_keypad *keypad = dev;
    struct input_dev *input = keypad->input;
    const struct stmpe_keypad_variant *variant = keypad->variant;
    u8 fifo[variant->num_data];
    int ret;
    int i;

    ret = stmpe_keypad_read_data(keypad, fifo);
    if (ret < 0)
        return IRQ_NONE;

    for (i = 0; i < variant->num_normal_data; i++) {
        u8 data = fifo[i];
        int row = (data & STMPE_KPC_DATA_ROW) >> 3;
        int col = data & STMPE_KPC_DATA_COL;
        int code = MATRIX_SCAN_CODE(row, col, STMPE_KEYPAD_ROW_SHIFT);
        bool up = data & STMPE_KPC_DATA_UP;

        if ((data & STMPE_KPC_DATA_NOKEY_MASK)
            == STMPE_KPC_DATA_NOKEY_MASK)
            continue;

        input_event(input, EV_MSC, MSC_SCAN, code);
        input_report_key(input, keypad->keymap[code], !up);
        input_sync(input);
    }

    return IRQ_HANDLED;
}

static int __devinit stmpe_keypad_altfunc_init(struct stmpe_keypad *keypad)
{
    const struct stmpe_keypad_variant *variant = keypad->variant;
    unsigned int col_gpios = variant->col_gpios;
    unsigned int row_gpios = variant->row_gpios;
    struct stmpe *stmpe = keypad->stmpe;
    unsigned int pins = 0;
    int i;

    /*
     * Figure out which pins need to be set to the keypad alternate
     * function.
     *
     * {cols,rows}_gpios are bitmasks of which pins on the chip can be used
     * for the keypad.
     *
     * keypad->{cols,rows} are a bitmask of which pins (of the ones useable
     * for the keypad) are used on the board.
     */

    for (i = 0; i < variant->max_cols; i++) {
        int num = __ffs(col_gpios);

        if (keypad->cols & (1 << i))
            pins |= 1 << num;

        col_gpios &= ~(1 << num);
    }

    for (i = 0; i < variant->max_rows; i++) {
        int num = __ffs(row_gpios);

        if (keypad->rows & (1 << i))
            pins |= 1 << num;

        row_gpios &= ~(1 << num);
    }

    return stmpe_set_altfunc(stmpe, pins, STMPE_BLOCK_KEYPAD);
}

static int __devinit stmpe_keypad_chip_init(struct stmpe_keypad *keypad)
{
    const struct stmpe_keypad_platform_data *plat = keypad->plat;
    const struct stmpe_keypad_variant *variant = keypad->variant;
    struct stmpe *stmpe = keypad->stmpe;
    int ret;

    if (plat->debounce_ms > STMPE_KEYPAD_MAX_DEBOUNCE)
        return -EINVAL;

    if (plat->scan_count > STMPE_KEYPAD_MAX_SCAN_COUNT)
        return -EINVAL;

    ret = stmpe_enable(stmpe, STMPE_BLOCK_KEYPAD);
    if (ret < 0)
        return ret;

    ret = stmpe_keypad_altfunc_init(keypad);
    if (ret < 0)
        return ret;

    ret = stmpe_reg_write(stmpe, STMPE_KPC_COL, keypad->cols);
    if (ret < 0)
        return ret;

    ret = stmpe_reg_write(stmpe, STMPE_KPC_ROW_LSB, keypad->rows);
    if (ret < 0)
        return ret;

    if (variant->max_rows > 8) {
        ret = stmpe_set_bits(stmpe, STMPE_KPC_ROW_MSB,
                     STMPE_KPC_ROW_MSB_ROWS,
                     keypad->rows >> 8);
        if (ret < 0)
            return ret;
    }

    ret = stmpe_set_bits(stmpe, STMPE_KPC_CTRL_MSB,
                 STMPE_KPC_CTRL_MSB_SCAN_COUNT,
                 plat->scan_count << 4);
    if (ret < 0)
        return ret;

    return stmpe_set_bits(stmpe, STMPE_KPC_CTRL_LSB,
                  STMPE_KPC_CTRL_LSB_SCAN |
                  STMPE_KPC_CTRL_LSB_DEBOUNCE,
                  STMPE_KPC_CTRL_LSB_SCAN |
                  (plat->debounce_ms << 1));
}

static int __devinit stmpe_keypad_probe(struct platform_device *pdev)
{
    struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
    struct stmpe_keypad_platform_data *plat;
    struct stmpe_keypad *keypad;
    struct input_dev *input;
    int ret;
    int irq;
    int i;

    plat = stmpe->pdata->keypad;
    if (!plat)
        return -ENODEV;

    irq = platform_get_irq(pdev, 0);
    if (irq < 0)
        return irq;

    keypad = kzalloc(sizeof(struct stmpe_keypad), GFP_KERNEL);
    if (!keypad)
        return -ENOMEM;

    input = input_allocate_device();
    if (!input) {
        ret = -ENOMEM;
        goto out_freekeypad;
    }

    input->name = "STMPE keypad";
    input->id.bustype = BUS_I2C;
    input->dev.parent = &pdev->dev;

    ret = matrix_keypad_build_keymap(plat->keymap_data, NULL,
                     STMPE_KEYPAD_MAX_ROWS,
                     STMPE_KEYPAD_MAX_COLS,
                     keypad->keymap, input);
    if (ret)
        goto out_freeinput;

    input_set_capability(input, EV_MSC, MSC_SCAN);
    if (!plat->no_autorepeat)
        __set_bit(EV_REP, input->evbit);

    for (i = 0; i < plat->keymap_data->keymap_size; i++) {
        unsigned int key = plat->keymap_data->keymap[i];

        keypad->cols |= 1 << KEY_COL(key);
        keypad->rows |= 1 << KEY_ROW(key);
    }

    keypad->stmpe = stmpe;
    keypad->plat = plat;
    keypad->input = input;
    keypad->variant = &stmpe_keypad_variants[stmpe->partnum];

    ret = stmpe_keypad_chip_init(keypad);
    if (ret < 0)
        goto out_freeinput;

    ret = input_register_device(input);
    if (ret) {
        dev_err(&pdev->dev,
            "unable to register input device: %d\n", ret);
        goto out_freeinput;
    }

    ret = request_threaded_irq(irq, NULL, stmpe_keypad_irq, IRQF_ONESHOT,
                   "stmpe-keypad", keypad);
    if (ret) {
        dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
        goto out_unregisterinput;
    }

    platform_set_drvdata(pdev, keypad);

    return 0;

out_unregisterinput:
    input_unregister_device(input);
    input = NULL;
out_freeinput:
    input_free_device(input);
out_freekeypad:
    kfree(keypad);
    return ret;
}

static int __devexit stmpe_keypad_remove(struct platform_device *pdev)
{
    struct stmpe_keypad *keypad = platform_get_drvdata(pdev);
    struct stmpe *stmpe = keypad->stmpe;
    int irq = platform_get_irq(pdev, 0);

    stmpe_disable(stmpe, STMPE_BLOCK_KEYPAD);

    free_irq(irq, keypad);
    input_unregister_device(keypad->input);
    platform_set_drvdata(pdev, NULL);
    kfree(keypad);

    return 0;
}

static struct platform_driver stmpe_keypad_driver = {
    .driver.name    = "stmpe-keypad",
    .driver.owner   = THIS_MODULE,
    .probe      = stmpe_keypad_probe,
    .remove     = __devexit_p(stmpe_keypad_remove),
};
module_platform_driver(stmpe_keypad_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("STMPExxxx keypad driver");
MODULE_AUTHOR("Rabin Vincent <[email protected]>");