nomadik-ske-keypad.c

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/*
 * Copyright (C) ST-Ericsson SA 2010
 *
 * Author: Naveen Kumar G <[email protected]> for ST-Ericsson
 * Author: Sundar Iyer <[email protected]> for ST-Ericsson
 *
 * License terms:GNU General Public License (GPL) version 2
 *
 * Keypad controller driver for the SKE (Scroll Key Encoder) module used in
 * the Nomadik 8815 and Ux500 platforms.
 */

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

#include <linux/platform_data/keypad-nomadik-ske.h>

/* SKE_CR bits */
#define SKE_KPMLT   (0x1 << 6)
#define SKE_KPCN    (0x7 << 3)
#define SKE_KPASEN  (0x1 << 2)
#define SKE_KPASON  (0x1 << 7)

/* SKE_IMSC bits */
#define SKE_KPIMA   (0x1 << 2)

/* SKE_ICR bits */
#define SKE_KPICS   (0x1 << 3)
#define SKE_KPICA   (0x1 << 2)

/* SKE_RIS bits */
#define SKE_KPRISA  (0x1 << 2)

#define SKE_KEYPAD_ROW_SHIFT    3
#define SKE_KPD_NUM_ROWS    8
#define SKE_KPD_NUM_COLS    8

/* keypad auto scan registers */
#define SKE_ASR0    0x20
#define SKE_ASR1    0x24
#define SKE_ASR2    0x28
#define SKE_ASR3    0x2C

#define SKE_NUM_ASRX_REGISTERS  (4)
#define KEY_PRESSED_DELAY   10

struct ske_keypad {
    int irq;
    void __iomem *reg_base;
    struct input_dev *input;
    const struct ske_keypad_platform_data *board;
    unsigned short keymap[SKE_KPD_NUM_ROWS * SKE_KPD_NUM_COLS];
    struct clk *clk;
    spinlock_t ske_keypad_lock;
};

static void ske_keypad_set_bits(struct ske_keypad *keypad, u16 addr,
        u8 mask, u8 data)
{
    u32 ret;

    spin_lock(&keypad->ske_keypad_lock);

    ret = readl(keypad->reg_base + addr);
    ret &= ~mask;
    ret |= data;
    writel(ret, keypad->reg_base + addr);

    spin_unlock(&keypad->ske_keypad_lock);
}

/*
 * ske_keypad_chip_init: init keypad controller configuration
 *
 * Enable Multi key press detection, auto scan mode
 */
static int __init ske_keypad_chip_init(struct ske_keypad *keypad)
{
    u32 value;
    int timeout = keypad->board->debounce_ms;

    /* check SKE_RIS to be 0 */
    while ((readl(keypad->reg_base + SKE_RIS) != 0x00000000) && timeout--)
        cpu_relax();

    if (!timeout)
        return -EINVAL;

    /*
     * set debounce value
     * keypad dbounce is configured in DBCR[15:8]
     * dbounce value in steps of 32/32.768 ms
     */
    spin_lock(&keypad->ske_keypad_lock);
    value = readl(keypad->reg_base + SKE_DBCR);
    value = value & 0xff;
    value |= ((keypad->board->debounce_ms * 32000)/32768) << 8;
    writel(value, keypad->reg_base + SKE_DBCR);
    spin_unlock(&keypad->ske_keypad_lock);

    /* enable multi key detection */
    ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPMLT);

    /*
     * set up the number of columns
     * KPCN[5:3] defines no. of keypad columns to be auto scanned
     */
    value = (keypad->board->kcol - 1) << 3;
    ske_keypad_set_bits(keypad, SKE_CR, SKE_KPCN, value);

    /* clear keypad interrupt for auto(and pending SW) scans */
    ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA | SKE_KPICS);

    /* un-mask keypad interrupts */
    ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);

    /* enable automatic scan */
    ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPASEN);

    return 0;
}

static void ske_keypad_report(struct ske_keypad *keypad, u8 status, int col)
{
    int row = 0, code, pos;
    struct input_dev *input = keypad->input;
    u32 ske_ris;
    int key_pressed;
    int num_of_rows;

    /* find out the row */
    num_of_rows = hweight8(status);
    do {
        pos = __ffs(status);
        row = pos;
        status &= ~(1 << pos);

        code = MATRIX_SCAN_CODE(row, col, SKE_KEYPAD_ROW_SHIFT);
        ske_ris = readl(keypad->reg_base + SKE_RIS);
        key_pressed = ske_ris & SKE_KPRISA;

        input_event(input, EV_MSC, MSC_SCAN, code);
        input_report_key(input, keypad->keymap[code], key_pressed);
        input_sync(input);
        num_of_rows--;
    } while (num_of_rows);
}

static void ske_keypad_read_data(struct ske_keypad *keypad)
{
    u8 status;
    int col = 0;
    int ske_asr, i;

    /*
     * Read the auto scan registers
     *
     * Each SKE_ASRx (x=0 to x=3) contains two row values.
     * lower byte contains row value for column 2*x,
     * upper byte contains row value for column 2*x + 1
     */
    for (i = 0; i < SKE_NUM_ASRX_REGISTERS; i++) {
        ske_asr = readl(keypad->reg_base + SKE_ASR0 + (4 * i));
        if (!ske_asr)
            continue;

        /* now that ASRx is zero, find out the coloumn x and row y */
        status = ske_asr & 0xff;
        if (status) {
            col = i * 2;
            ske_keypad_report(keypad, status, col);
        }
        status = (ske_asr & 0xff00) >> 8;
        if (status) {
            col = (i * 2) + 1;
            ske_keypad_report(keypad, status, col);
        }
    }
}

static irqreturn_t ske_keypad_irq(int irq, void *dev_id)
{
    struct ske_keypad *keypad = dev_id;
    int timeout = keypad->board->debounce_ms;

    /* disable auto scan interrupt; mask the interrupt generated */
    ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
    ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA);

    while ((readl(keypad->reg_base + SKE_CR) & SKE_KPASON) && --timeout)
        cpu_relax();

    /* SKEx registers are stable and can be read */
    ske_keypad_read_data(keypad);

    /* wait until raw interrupt is clear */
    while ((readl(keypad->reg_base + SKE_RIS)) && --timeout)
        msleep(KEY_PRESSED_DELAY);

    /* enable auto scan interrupts */
    ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);

    return IRQ_HANDLED;
}

static int __init ske_keypad_probe(struct platform_device *pdev)
{
    const struct ske_keypad_platform_data *plat = pdev->dev.platform_data;
    struct ske_keypad *keypad;
    struct input_dev *input;
    struct resource *res;
    int irq;
    int error;

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

    irq = platform_get_irq(pdev, 0);
    if (irq < 0) {
        dev_err(&pdev->dev, "failed to get keypad irq\n");
        return -EINVAL;
    }

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res) {
        dev_err(&pdev->dev, "missing platform resources\n");
        return -EINVAL;
    }

    keypad = kzalloc(sizeof(struct ske_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->irq = irq;
    keypad->board = plat;
    keypad->input = input;
    spin_lock_init(&keypad->ske_keypad_lock);

    if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
        dev_err(&pdev->dev, "failed to request I/O memory\n");
        error = -EBUSY;
        goto err_free_mem;
    }

    keypad->reg_base = ioremap(res->start, resource_size(res));
    if (!keypad->reg_base) {
        dev_err(&pdev->dev, "failed to remap I/O memory\n");
        error = -ENXIO;
        goto err_free_mem_region;
    }

    keypad->clk = clk_get(&pdev->dev, NULL);
    if (IS_ERR(keypad->clk)) {
        dev_err(&pdev->dev, "failed to get clk\n");
        error = PTR_ERR(keypad->clk);
        goto err_iounmap;
    }

    input->id.bustype = BUS_HOST;
    input->name = "ux500-ske-keypad";
    input->dev.parent = &pdev->dev;

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

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

    clk_enable(keypad->clk);

    /* go through board initialization helpers */
    if (keypad->board->init)
        keypad->board->init();

    error = ske_keypad_chip_init(keypad);
    if (error) {
        dev_err(&pdev->dev, "unable to init keypad hardware\n");
        goto err_clk_disable;
    }

    error = request_threaded_irq(keypad->irq, NULL, ske_keypad_irq,
                     IRQF_ONESHOT, "ske-keypad", keypad);
    if (error) {
        dev_err(&pdev->dev, "allocate irq %d failed\n", keypad->irq);
        goto err_clk_disable;
    }

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

    if (plat->wakeup_enable)
        device_init_wakeup(&pdev->dev, true);

    platform_set_drvdata(pdev, keypad);

    return 0;

err_free_irq:
    free_irq(keypad->irq, keypad);
err_clk_disable:
    clk_disable(keypad->clk);
    clk_put(keypad->clk);
err_iounmap:
    iounmap(keypad->reg_base);
err_free_mem_region:
    release_mem_region(res->start, resource_size(res));
err_free_mem:
    input_free_device(input);
    kfree(keypad);
    return error;
}

static int __devexit ske_keypad_remove(struct platform_device *pdev)
{
    struct ske_keypad *keypad = platform_get_drvdata(pdev);
    struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

    free_irq(keypad->irq, keypad);

    input_unregister_device(keypad->input);

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

    if (keypad->board->exit)
        keypad->board->exit();

    iounmap(keypad->reg_base);
    release_mem_region(res->start, resource_size(res));
    kfree(keypad);

    return 0;
}

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

    if (device_may_wakeup(dev))
        enable_irq_wake(irq);
    else
        ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);

    return 0;
}

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

    if (device_may_wakeup(dev))
        disable_irq_wake(irq);
    else
        ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);

    return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(ske_keypad_dev_pm_ops,
             ske_keypad_suspend, ske_keypad_resume);

static struct platform_driver ske_keypad_driver = {
    .driver = {
        .name = "nmk-ske-keypad",
        .owner  = THIS_MODULE,
        .pm = &ske_keypad_dev_pm_ops,
    },
    .remove = __devexit_p(ske_keypad_remove),
};

static int __init ske_keypad_init(void)
{
    return platform_driver_probe(&ske_keypad_driver, ske_keypad_probe);
}
module_init(ske_keypad_init);

static void __exit ske_keypad_exit(void)
{
    platform_driver_unregister(&ske_keypad_driver);
}
module_exit(ske_keypad_exit);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Naveen Kumar <[email protected]> / Sundar Iyer <[email protected]>");
MODULE_DESCRIPTION("Nomadik Scroll-Key-Encoder Keypad Driver");
MODULE_ALIAS("platform:nomadik-ske-keypad");