ep93xx_keypad.c

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/*
 * Driver for the Cirrus EP93xx matrix keypad controller.
 *
 * Copyright (c) 2008 H Hartley Sweeten <[email protected]>
 *
 * Based on the pxa27x matrix keypad controller by Rodolfo Giometti.
 *
 * 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.
 *
 * NOTE:
 *
 * The 3-key reset is triggered by pressing the 3 keys in
 * Row 0, Columns 2, 4, and 7 at the same time.  This action can
 * be disabled by setting the EP93XX_KEYPAD_DISABLE_3_KEY flag.
 *
 * Normal operation for the matrix does not autorepeat the key press.
 * This action can be enabled by setting the EP93XX_KEYPAD_AUTOREPEAT
 * flag.
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/input/matrix_keypad.h>
#include <linux/slab.h>

#include <mach/hardware.h>
#include <linux/platform_data/keypad-ep93xx.h>

/*
 * Keypad Interface Register offsets
 */
#define KEY_INIT        0x00    /* Key Scan Initialization register */
#define KEY_DIAG        0x04    /* Key Scan Diagnostic register */
#define KEY_REG         0x08    /* Key Value Capture register */

/* Key Scan Initialization Register bit defines */
#define KEY_INIT_DBNC_MASK  (0x00ff0000)
#define KEY_INIT_DBNC_SHIFT (16)
#define KEY_INIT_DIS3KY     (1<<15)
#define KEY_INIT_DIAG       (1<<14)
#define KEY_INIT_BACK       (1<<13)
#define KEY_INIT_T2     (1<<12)
#define KEY_INIT_PRSCL_MASK (0x000003ff)
#define KEY_INIT_PRSCL_SHIFT    (0)

/* Key Scan Diagnostic Register bit defines */
#define KEY_DIAG_MASK       (0x0000003f)
#define KEY_DIAG_SHIFT      (0)

/* Key Value Capture Register bit defines */
#define KEY_REG_K       (1<<15)
#define KEY_REG_INT     (1<<14)
#define KEY_REG_2KEYS       (1<<13)
#define KEY_REG_1KEY        (1<<12)
#define KEY_REG_KEY2_MASK   (0x00000fc0)
#define KEY_REG_KEY2_SHIFT  (6)
#define KEY_REG_KEY1_MASK   (0x0000003f)
#define KEY_REG_KEY1_SHIFT  (0)

#define EP93XX_MATRIX_SIZE  (EP93XX_MATRIX_ROWS * EP93XX_MATRIX_COLS)

struct ep93xx_keypad {
    struct ep93xx_keypad_platform_data *pdata;
    struct input_dev *input_dev;
    struct clk *clk;

    void __iomem *mmio_base;

    unsigned short keycodes[EP93XX_MATRIX_SIZE];

    int key1;
    int key2;

    int irq;

    bool enabled;
};

static irqreturn_t ep93xx_keypad_irq_handler(int irq, void *dev_id)
{
    struct ep93xx_keypad *keypad = dev_id;
    struct input_dev *input_dev = keypad->input_dev;
    unsigned int status;
    int keycode, key1, key2;

    status = __raw_readl(keypad->mmio_base + KEY_REG);

    keycode = (status & KEY_REG_KEY1_MASK) >> KEY_REG_KEY1_SHIFT;
    key1 = keypad->keycodes[keycode];

    keycode = (status & KEY_REG_KEY2_MASK) >> KEY_REG_KEY2_SHIFT;
    key2 = keypad->keycodes[keycode];

    if (status & KEY_REG_2KEYS) {
        if (keypad->key1 && key1 != keypad->key1 && key2 != keypad->key1)
            input_report_key(input_dev, keypad->key1, 0);

        if (keypad->key2 && key1 != keypad->key2 && key2 != keypad->key2)
            input_report_key(input_dev, keypad->key2, 0);

        input_report_key(input_dev, key1, 1);
        input_report_key(input_dev, key2, 1);

        keypad->key1 = key1;
        keypad->key2 = key2;

    } else if (status & KEY_REG_1KEY) {
        if (keypad->key1 && key1 != keypad->key1)
            input_report_key(input_dev, keypad->key1, 0);

        if (keypad->key2 && key1 != keypad->key2)
            input_report_key(input_dev, keypad->key2, 0);

        input_report_key(input_dev, key1, 1);

        keypad->key1 = key1;
        keypad->key2 = 0;

    } else {
        input_report_key(input_dev, keypad->key1, 0);
        input_report_key(input_dev, keypad->key2, 0);

        keypad->key1 = keypad->key2 = 0;
    }
    input_sync(input_dev);

    return IRQ_HANDLED;
}

static void ep93xx_keypad_config(struct ep93xx_keypad *keypad)
{
    struct ep93xx_keypad_platform_data *pdata = keypad->pdata;
    unsigned int val = 0;

    if (pdata->flags & EP93XX_KEYPAD_KDIV)
        clk_set_rate(keypad->clk, EP93XX_KEYTCHCLK_DIV4);
    else
        clk_set_rate(keypad->clk, EP93XX_KEYTCHCLK_DIV16);

    if (pdata->flags & EP93XX_KEYPAD_DISABLE_3_KEY)
        val |= KEY_INIT_DIS3KY;
    if (pdata->flags & EP93XX_KEYPAD_DIAG_MODE)
        val |= KEY_INIT_DIAG;
    if (pdata->flags & EP93XX_KEYPAD_BACK_DRIVE)
        val |= KEY_INIT_BACK;
    if (pdata->flags & EP93XX_KEYPAD_TEST_MODE)
        val |= KEY_INIT_T2;

    val |= ((pdata->debounce << KEY_INIT_DBNC_SHIFT) & KEY_INIT_DBNC_MASK);

    val |= ((pdata->prescale << KEY_INIT_PRSCL_SHIFT) & KEY_INIT_PRSCL_MASK);

    __raw_writel(val, keypad->mmio_base + KEY_INIT);
}

static int ep93xx_keypad_open(struct input_dev *pdev)
{
    struct ep93xx_keypad *keypad = input_get_drvdata(pdev);

    if (!keypad->enabled) {
        ep93xx_keypad_config(keypad);
        clk_enable(keypad->clk);
        keypad->enabled = true;
    }

    return 0;
}

static void ep93xx_keypad_close(struct input_dev *pdev)
{
    struct ep93xx_keypad *keypad = input_get_drvdata(pdev);

    if (keypad->enabled) {
        clk_disable(keypad->clk);
        keypad->enabled = false;
    }
}


#ifdef CONFIG_PM_SLEEP
static int ep93xx_keypad_suspend(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct ep93xx_keypad *keypad = platform_get_drvdata(pdev);
    struct input_dev *input_dev = keypad->input_dev;

    mutex_lock(&input_dev->mutex);

    if (keypad->enabled) {
        clk_disable(keypad->clk);
        keypad->enabled = false;
    }

    mutex_unlock(&input_dev->mutex);

    if (device_may_wakeup(&pdev->dev))
        enable_irq_wake(keypad->irq);

    return 0;
}

static int ep93xx_keypad_resume(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct ep93xx_keypad *keypad = platform_get_drvdata(pdev);
    struct input_dev *input_dev = keypad->input_dev;

    if (device_may_wakeup(&pdev->dev))
        disable_irq_wake(keypad->irq);

    mutex_lock(&input_dev->mutex);

    if (input_dev->users) {
        if (!keypad->enabled) {
            ep93xx_keypad_config(keypad);
            clk_enable(keypad->clk);
            keypad->enabled = true;
        }
    }

    mutex_unlock(&input_dev->mutex);

    return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(ep93xx_keypad_pm_ops,
             ep93xx_keypad_suspend, ep93xx_keypad_resume);

static int __devinit ep93xx_keypad_probe(struct platform_device *pdev)
{
    struct ep93xx_keypad *keypad;
    const struct matrix_keymap_data *keymap_data;
    struct input_dev *input_dev;
    struct resource *res;
    int err;

    keypad = kzalloc(sizeof(struct ep93xx_keypad), GFP_KERNEL);
    if (!keypad)
        return -ENOMEM;

    keypad->pdata = pdev->dev.platform_data;
    if (!keypad->pdata) {
        err = -EINVAL;
        goto failed_free;
    }

    keymap_data = keypad->pdata->keymap_data;
    if (!keymap_data) {
        err = -EINVAL;
        goto failed_free;
    }

    keypad->irq = platform_get_irq(pdev, 0);
    if (!keypad->irq) {
        err = -ENXIO;
        goto failed_free;
    }

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res) {
        err = -ENXIO;
        goto failed_free;
    }

    res = request_mem_region(res->start, resource_size(res), pdev->name);
    if (!res) {
        err = -EBUSY;
        goto failed_free;
    }

    keypad->mmio_base = ioremap(res->start, resource_size(res));
    if (keypad->mmio_base == NULL) {
        err = -ENXIO;
        goto failed_free_mem;
    }

    err = ep93xx_keypad_acquire_gpio(pdev);
    if (err)
        goto failed_free_io;

    keypad->clk = clk_get(&pdev->dev, NULL);
    if (IS_ERR(keypad->clk)) {
        err = PTR_ERR(keypad->clk);
        goto failed_free_gpio;
    }

    input_dev = input_allocate_device();
    if (!input_dev) {
        err = -ENOMEM;
        goto failed_put_clk;
    }

    keypad->input_dev = input_dev;

    input_dev->name = pdev->name;
    input_dev->id.bustype = BUS_HOST;
    input_dev->open = ep93xx_keypad_open;
    input_dev->close = ep93xx_keypad_close;
    input_dev->dev.parent = &pdev->dev;

    err = matrix_keypad_build_keymap(keymap_data, NULL,
                     EP93XX_MATRIX_ROWS, EP93XX_MATRIX_COLS,
                     keypad->keycodes, input_dev);
    if (err)
        goto failed_free_dev;

    if (keypad->pdata->flags & EP93XX_KEYPAD_AUTOREPEAT)
        __set_bit(EV_REP, input_dev->evbit);
    input_set_drvdata(input_dev, keypad);

    err = request_irq(keypad->irq, ep93xx_keypad_irq_handler,
              0, pdev->name, keypad);
    if (err)
        goto failed_free_dev;

    err = input_register_device(input_dev);
    if (err)
        goto failed_free_irq;

    platform_set_drvdata(pdev, keypad);
    device_init_wakeup(&pdev->dev, 1);

    return 0;

failed_free_irq:
    free_irq(keypad->irq, pdev);
    platform_set_drvdata(pdev, NULL);
failed_free_dev:
    input_free_device(input_dev);
failed_put_clk:
    clk_put(keypad->clk);
failed_free_gpio:
    ep93xx_keypad_release_gpio(pdev);
failed_free_io:
    iounmap(keypad->mmio_base);
failed_free_mem:
    release_mem_region(res->start, resource_size(res));
failed_free:
    kfree(keypad);
    return err;
}

static int __devexit ep93xx_keypad_remove(struct platform_device *pdev)
{
    struct ep93xx_keypad *keypad = platform_get_drvdata(pdev);
    struct resource *res;

    free_irq(keypad->irq, pdev);

    platform_set_drvdata(pdev, NULL);

    if (keypad->enabled)
        clk_disable(keypad->clk);
    clk_put(keypad->clk);

    input_unregister_device(keypad->input_dev);

    ep93xx_keypad_release_gpio(pdev);

    iounmap(keypad->mmio_base);

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    release_mem_region(res->start, resource_size(res));

    kfree(keypad);

    return 0;
}

static struct platform_driver ep93xx_keypad_driver = {
    .driver     = {
        .name   = "ep93xx-keypad",
        .owner  = THIS_MODULE,
        .pm = &ep93xx_keypad_pm_ops,
    },
    .probe      = ep93xx_keypad_probe,
    .remove     = __devexit_p(ep93xx_keypad_remove),
};
module_platform_driver(ep93xx_keypad_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("H Hartley Sweeten <[email protected]>");
MODULE_DESCRIPTION("EP93xx Matrix Keypad Controller");
MODULE_ALIAS("platform:ep93xx-keypad");