tc3589x-keypad.c

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/*
 * Copyright (C) ST-Ericsson SA 2010
 *
 * Author: Jayeeta Banerjee <[email protected]>
 * Author: Sundar Iyer <[email protected]>
 *
 * License Terms: GNU General Public License, version 2
 *
 * TC35893 MFD Keypad Controller driver
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/platform_device.h>
#include <linux/input/matrix_keypad.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/mfd/tc3589x.h>

/* Maximum supported keypad matrix row/columns size */
#define TC3589x_MAX_KPROW               8
#define TC3589x_MAX_KPCOL               12

/* keypad related Constants */
#define TC3589x_MAX_DEBOUNCE_SETTLE     0xFF
#define DEDICATED_KEY_VAL       0xFF

/* Pull up/down masks */
#define TC3589x_NO_PULL_MASK        0x0
#define TC3589x_PULL_DOWN_MASK      0x1
#define TC3589x_PULL_UP_MASK        0x2
#define TC3589x_PULLUP_ALL_MASK     0xAA
#define TC3589x_IO_PULL_VAL(index, mask)    ((mask)<<((index)%4)*2))

/* Bit masks for IOCFG register */
#define IOCFG_BALLCFG       0x01
#define IOCFG_IG        0x08

#define KP_EVCODE_COL_MASK  0x0F
#define KP_EVCODE_ROW_MASK  0x70
#define KP_RELEASE_EVT_MASK 0x80

#define KP_ROW_SHIFT        4

#define KP_NO_VALID_KEY_MASK    0x7F

/* bit masks for RESTCTRL register */
#define TC3589x_KBDRST      0x2
#define TC3589x_IRQRST      0x10
#define TC3589x_RESET_ALL   0x1B

/* KBDMFS register bit mask */
#define TC3589x_KBDMFS_EN   0x1

/* CLKEN register bitmask */
#define KPD_CLK_EN      0x1

/* RSTINTCLR register bit mask */
#define IRQ_CLEAR       0x1

/* bit masks for keyboard interrupts*/
#define TC3589x_EVT_LOSS_INT    0x8
#define TC3589x_EVT_INT     0x4
#define TC3589x_KBD_LOSS_INT    0x2
#define TC3589x_KBD_INT     0x1

/* bit masks for keyboard interrupt clear*/
#define TC3589x_EVT_INT_CLR 0x2
#define TC3589x_KBD_INT_CLR 0x1

#define TC3589x_KBD_KEYMAP_SIZE     64

struct tc_keypad {
    struct tc3589x *tc3589x;
    struct input_dev *input;
    const struct tc3589x_keypad_platform_data *board;
    unsigned int krow;
    unsigned int kcol;
    unsigned short keymap[TC3589x_KBD_KEYMAP_SIZE];
    bool keypad_stopped;
};

static int tc3589x_keypad_init_key_hardware(struct tc_keypad *keypad)
{
    int ret;
    struct tc3589x *tc3589x = keypad->tc3589x;
    const struct tc3589x_keypad_platform_data *board = keypad->board;

    /* validate platform configuration */
    if (board->kcol > TC3589x_MAX_KPCOL || board->krow > TC3589x_MAX_KPROW)
        return -EINVAL;

    /* configure KBDSIZE 4 LSbits for cols and 4 MSbits for rows */
    ret = tc3589x_reg_write(tc3589x, TC3589x_KBDSIZE,
            (board->krow << KP_ROW_SHIFT) | board->kcol);
    if (ret < 0)
        return ret;

    /* configure dedicated key config, no dedicated key selected */
    ret = tc3589x_reg_write(tc3589x, TC3589x_KBCFG_LSB, DEDICATED_KEY_VAL);
    if (ret < 0)
        return ret;

    ret = tc3589x_reg_write(tc3589x, TC3589x_KBCFG_MSB, DEDICATED_KEY_VAL);
    if (ret < 0)
        return ret;

    /* Configure settle time */
    ret = tc3589x_reg_write(tc3589x, TC3589x_KBDSETTLE_REG,
                board->settle_time);
    if (ret < 0)
        return ret;

    /* Configure debounce time */
    ret = tc3589x_reg_write(tc3589x, TC3589x_KBDBOUNCE,
                board->debounce_period);
    if (ret < 0)
        return ret;

    /* Start of initialise keypad GPIOs */
    ret = tc3589x_set_bits(tc3589x, TC3589x_IOCFG, 0x0, IOCFG_IG);
    if (ret < 0)
        return ret;

    /* Configure pull-up resistors for all row GPIOs */
    ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG0_LSB,
                    TC3589x_PULLUP_ALL_MASK);
    if (ret < 0)
        return ret;

    ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG0_MSB,
                    TC3589x_PULLUP_ALL_MASK);
    if (ret < 0)
        return ret;

    /* Configure pull-up resistors for all column GPIOs */
    ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG1_LSB,
            TC3589x_PULLUP_ALL_MASK);
    if (ret < 0)
        return ret;

    ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG1_MSB,
            TC3589x_PULLUP_ALL_MASK);
    if (ret < 0)
        return ret;

    ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG2_LSB,
            TC3589x_PULLUP_ALL_MASK);

    return ret;
}

#define TC35893_DATA_REGS       4
#define TC35893_KEYCODE_FIFO_EMPTY  0x7f
#define TC35893_KEYCODE_FIFO_CLEAR  0xff
#define TC35893_KEYPAD_ROW_SHIFT    0x3

static irqreturn_t tc3589x_keypad_irq(int irq, void *dev)
{
    struct tc_keypad *keypad = dev;
    struct tc3589x *tc3589x = keypad->tc3589x;
    u8 i, row_index, col_index, kbd_code, up;
    u8 code;

    for (i = 0; i < TC35893_DATA_REGS * 2; i++) {
        kbd_code = tc3589x_reg_read(tc3589x, TC3589x_EVTCODE_FIFO);

        /* loop till fifo is empty and no more keys are pressed */
        if (kbd_code == TC35893_KEYCODE_FIFO_EMPTY ||
                kbd_code == TC35893_KEYCODE_FIFO_CLEAR)
            continue;

        /* valid key is found */
        col_index = kbd_code & KP_EVCODE_COL_MASK;
        row_index = (kbd_code & KP_EVCODE_ROW_MASK) >> KP_ROW_SHIFT;
        code = MATRIX_SCAN_CODE(row_index, col_index,
                        TC35893_KEYPAD_ROW_SHIFT);
        up = kbd_code & KP_RELEASE_EVT_MASK;

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

    /* clear IRQ */
    tc3589x_set_bits(tc3589x, TC3589x_KBDIC,
            0x0, TC3589x_EVT_INT_CLR | TC3589x_KBD_INT_CLR);
    /* enable IRQ */
    tc3589x_set_bits(tc3589x, TC3589x_KBDMSK,
            0x0, TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT);

    return IRQ_HANDLED;
}

static int tc3589x_keypad_enable(struct tc_keypad *keypad)
{
    struct tc3589x *tc3589x = keypad->tc3589x;
    int ret;

    /* pull the keypad module out of reset */
    ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL, TC3589x_KBDRST, 0x0);
    if (ret < 0)
        return ret;

    /* configure KBDMFS */
    ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMFS, 0x0, TC3589x_KBDMFS_EN);
    if (ret < 0)
        return ret;

    /* enable the keypad clock */
    ret = tc3589x_set_bits(tc3589x, TC3589x_CLKEN, 0x0, KPD_CLK_EN);
    if (ret < 0)
        return ret;

    /* clear pending IRQs */
    ret =  tc3589x_set_bits(tc3589x, TC3589x_RSTINTCLR, 0x0, 0x1);
    if (ret < 0)
        return ret;

    /* enable the IRQs */
    ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMSK, 0x0,
                    TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT);
    if (ret < 0)
        return ret;

    keypad->keypad_stopped = false;

    return ret;
}

static int tc3589x_keypad_disable(struct tc_keypad *keypad)
{
    struct tc3589x *tc3589x = keypad->tc3589x;
    int ret;

    /* clear IRQ */
    ret = tc3589x_set_bits(tc3589x, TC3589x_KBDIC,
            0x0, TC3589x_EVT_INT_CLR | TC3589x_KBD_INT_CLR);
    if (ret < 0)
        return ret;

    /* disable all interrupts */
    ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMSK,
            ~(TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT), 0x0);
    if (ret < 0)
        return ret;

    /* disable the keypad module */
    ret = tc3589x_set_bits(tc3589x, TC3589x_CLKEN, 0x1, 0x0);
    if (ret < 0)
        return ret;

    /* put the keypad module into reset */
    ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL, TC3589x_KBDRST, 0x1);

    keypad->keypad_stopped = true;

    return ret;
}

static int tc3589x_keypad_open(struct input_dev *input)
{
    int error;
    struct tc_keypad *keypad = input_get_drvdata(input);

    /* enable the keypad module */
    error = tc3589x_keypad_enable(keypad);
    if (error < 0) {
        dev_err(&input->dev, "failed to enable keypad module\n");
        return error;
    }

    error = tc3589x_keypad_init_key_hardware(keypad);
    if (error < 0) {
        dev_err(&input->dev, "failed to configure keypad module\n");
        return error;
    }

    return 0;
}

static void tc3589x_keypad_close(struct input_dev *input)
{
    struct tc_keypad *keypad = input_get_drvdata(input);

    /* disable the keypad module */
    tc3589x_keypad_disable(keypad);
}

static int __devinit tc3589x_keypad_probe(struct platform_device *pdev)
{
    struct tc3589x *tc3589x = dev_get_drvdata(pdev->dev.parent);
    struct tc_keypad *keypad;
    struct input_dev *input;
    const struct tc3589x_keypad_platform_data *plat;
    int error, irq;

    plat = tc3589x->pdata->keypad;
    if (!plat) {
        dev_err(&pdev->dev, "invalid keypad platform data\n");
        return -EINVAL;
    }

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

    keypad = kzalloc(sizeof(struct tc_keypad), GFP_KERNEL);
    input = input_allocate_device();
    if (!keypad || !input) {
        dev_err(&pdev->dev, "failed to allocate keypad memory\n");
        error = -ENOMEM;
        goto err_free_mem;
    }

    keypad->board = plat;
    keypad->input = input;
    keypad->tc3589x = tc3589x;

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

    input->open = tc3589x_keypad_open;
    input->close = tc3589x_keypad_close;

    error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
                       TC3589x_MAX_KPROW, TC3589x_MAX_KPCOL,
                       keypad->keymap, input);
    if (error) {
        dev_err(&pdev->dev, "Failed to build keymap\n");
        goto err_free_mem;
    }

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

    input_set_drvdata(input, keypad);

    error = request_threaded_irq(irq, NULL,
            tc3589x_keypad_irq, plat->irqtype,
            "tc3589x-keypad", keypad);
    if (error < 0) {
        dev_err(&pdev->dev,
                "Could not allocate irq %d,error %d\n",
                irq, error);
        goto err_free_mem;
    }

    error = input_register_device(input);
    if (error) {
        dev_err(&pdev->dev, "Could not register input device\n");
        goto err_free_irq;
    }

    /* let platform decide if keypad is a wakeup source or not */
    device_init_wakeup(&pdev->dev, plat->enable_wakeup);
    device_set_wakeup_capable(&pdev->dev, plat->enable_wakeup);

    platform_set_drvdata(pdev, keypad);

    return 0;

err_free_irq:
    free_irq(irq, keypad);
err_free_mem:
    input_free_device(input);
    kfree(keypad);
    return error;
}

static int __devexit tc3589x_keypad_remove(struct platform_device *pdev)
{
    struct tc_keypad *keypad = platform_get_drvdata(pdev);
    int irq = platform_get_irq(pdev, 0);

    if (!keypad->keypad_stopped)
        tc3589x_keypad_disable(keypad);

    free_irq(irq, keypad);

    input_unregister_device(keypad->input);

    kfree(keypad);

    return 0;
}

#ifdef CONFIG_PM_SLEEP
static int tc3589x_keypad_suspend(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct tc_keypad *keypad = platform_get_drvdata(pdev);
    int irq = platform_get_irq(pdev, 0);

    /* keypad is already off; we do nothing */
    if (keypad->keypad_stopped)
        return 0;

    /* if device is not a wakeup source, disable it for powersave */
    if (!device_may_wakeup(&pdev->dev))
        tc3589x_keypad_disable(keypad);
    else
        enable_irq_wake(irq);

    return 0;
}

static int tc3589x_keypad_resume(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct tc_keypad *keypad = platform_get_drvdata(pdev);
    int irq = platform_get_irq(pdev, 0);

    if (!keypad->keypad_stopped)
        return 0;

    /* enable the device to resume normal operations */
    if (!device_may_wakeup(&pdev->dev))
        tc3589x_keypad_enable(keypad);
    else
        disable_irq_wake(irq);

    return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(tc3589x_keypad_dev_pm_ops,
             tc3589x_keypad_suspend, tc3589x_keypad_resume);

static struct platform_driver tc3589x_keypad_driver = {
    .driver = {
        .name   = "tc3589x-keypad",
        .owner  = THIS_MODULE,
        .pm = &tc3589x_keypad_dev_pm_ops,
    },
    .probe  = tc3589x_keypad_probe,
    .remove = __devexit_p(tc3589x_keypad_remove),
};
module_platform_driver(tc3589x_keypad_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Jayeeta Banerjee/Sundar Iyer");
MODULE_DESCRIPTION("TC35893 Keypad Driver");
MODULE_ALIAS("platform:tc3589x-keypad");