samsung-keypad.c

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/*
 * Samsung keypad driver
 *
 * Copyright (C) 2010 Samsung Electronics Co.Ltd
 * Author: Joonyoung Shim <[email protected]>
 * Author: Donghwa Lee <[email protected]>
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/sched.h>
#include <linux/input/samsung-keypad.h>

#define SAMSUNG_KEYIFCON            0x00
#define SAMSUNG_KEYIFSTSCLR         0x04
#define SAMSUNG_KEYIFCOL            0x08
#define SAMSUNG_KEYIFROW            0x0c
#define SAMSUNG_KEYIFFC             0x10

/* SAMSUNG_KEYIFCON */
#define SAMSUNG_KEYIFCON_INT_F_EN       (1 << 0)
#define SAMSUNG_KEYIFCON_INT_R_EN       (1 << 1)
#define SAMSUNG_KEYIFCON_DF_EN          (1 << 2)
#define SAMSUNG_KEYIFCON_FC_EN          (1 << 3)
#define SAMSUNG_KEYIFCON_WAKEUPEN       (1 << 4)

/* SAMSUNG_KEYIFSTSCLR */
#define SAMSUNG_KEYIFSTSCLR_P_INT_MASK      (0xff << 0)
#define SAMSUNG_KEYIFSTSCLR_R_INT_MASK      (0xff << 8)
#define SAMSUNG_KEYIFSTSCLR_R_INT_OFFSET    8
#define S5PV210_KEYIFSTSCLR_P_INT_MASK      (0x3fff << 0)
#define S5PV210_KEYIFSTSCLR_R_INT_MASK      (0x3fff << 16)
#define S5PV210_KEYIFSTSCLR_R_INT_OFFSET    16

/* SAMSUNG_KEYIFCOL */
#define SAMSUNG_KEYIFCOL_MASK           (0xff << 0)
#define S5PV210_KEYIFCOLEN_MASK         (0xff << 8)

/* SAMSUNG_KEYIFROW */
#define SAMSUNG_KEYIFROW_MASK           (0xff << 0)
#define S5PV210_KEYIFROW_MASK           (0x3fff << 0)

/* SAMSUNG_KEYIFFC */
#define SAMSUNG_KEYIFFC_MASK            (0x3ff << 0)

enum samsung_keypad_type {
    KEYPAD_TYPE_SAMSUNG,
    KEYPAD_TYPE_S5PV210,
};

struct samsung_keypad {
    struct input_dev *input_dev;
    struct platform_device *pdev;
    struct clk *clk;
    void __iomem *base;
    wait_queue_head_t wait;
    bool stopped;
    bool wake_enabled;
    int irq;
    enum samsung_keypad_type type;
    unsigned int row_shift;
    unsigned int rows;
    unsigned int cols;
    unsigned int row_state[SAMSUNG_MAX_COLS];
#ifdef CONFIG_OF
    int row_gpios[SAMSUNG_MAX_ROWS];
    int col_gpios[SAMSUNG_MAX_COLS];
#endif
    unsigned short keycodes[];
};

static void samsung_keypad_scan(struct samsung_keypad *keypad,
                unsigned int *row_state)
{
    unsigned int col;
    unsigned int val;

    for (col = 0; col < keypad->cols; col++) {
        if (keypad->type == KEYPAD_TYPE_S5PV210) {
            val = S5PV210_KEYIFCOLEN_MASK;
            val &= ~(1 << col) << 8;
        } else {
            val = SAMSUNG_KEYIFCOL_MASK;
            val &= ~(1 << col);
        }

        writel(val, keypad->base + SAMSUNG_KEYIFCOL);
        mdelay(1);

        val = readl(keypad->base + SAMSUNG_KEYIFROW);
        row_state[col] = ~val & ((1 << keypad->rows) - 1);
    }

    /* KEYIFCOL reg clear */
    writel(0, keypad->base + SAMSUNG_KEYIFCOL);
}

static bool samsung_keypad_report(struct samsung_keypad *keypad,
                  unsigned int *row_state)
{
    struct input_dev *input_dev = keypad->input_dev;
    unsigned int changed;
    unsigned int pressed;
    unsigned int key_down = 0;
    unsigned int val;
    unsigned int col, row;

    for (col = 0; col < keypad->cols; col++) {
        changed = row_state[col] ^ keypad->row_state[col];
        key_down |= row_state[col];
        if (!changed)
            continue;

        for (row = 0; row < keypad->rows; row++) {
            if (!(changed & (1 << row)))
                continue;

            pressed = row_state[col] & (1 << row);

            dev_dbg(&keypad->input_dev->dev,
                "key %s, row: %d, col: %d\n",
                pressed ? "pressed" : "released", row, col);

            val = MATRIX_SCAN_CODE(row, col, keypad->row_shift);

            input_event(input_dev, EV_MSC, MSC_SCAN, val);
            input_report_key(input_dev,
                    keypad->keycodes[val], pressed);
        }
        input_sync(keypad->input_dev);
    }

    memcpy(keypad->row_state, row_state, sizeof(keypad->row_state));

    return key_down;
}

static irqreturn_t samsung_keypad_irq(int irq, void *dev_id)
{
    struct samsung_keypad *keypad = dev_id;
    unsigned int row_state[SAMSUNG_MAX_COLS];
    unsigned int val;
    bool key_down;

    pm_runtime_get_sync(&keypad->pdev->dev);

    do {
        val = readl(keypad->base + SAMSUNG_KEYIFSTSCLR);
        /* Clear interrupt. */
        writel(~0x0, keypad->base + SAMSUNG_KEYIFSTSCLR);

        samsung_keypad_scan(keypad, row_state);

        key_down = samsung_keypad_report(keypad, row_state);
        if (key_down)
            wait_event_timeout(keypad->wait, keypad->stopped,
                       msecs_to_jiffies(50));

    } while (key_down && !keypad->stopped);

    pm_runtime_put(&keypad->pdev->dev);

    return IRQ_HANDLED;
}

static void samsung_keypad_start(struct samsung_keypad *keypad)
{
    unsigned int val;

    pm_runtime_get_sync(&keypad->pdev->dev);

    /* Tell IRQ thread that it may poll the device. */
    keypad->stopped = false;

    clk_enable(keypad->clk);

    /* Enable interrupt bits. */
    val = readl(keypad->base + SAMSUNG_KEYIFCON);
    val |= SAMSUNG_KEYIFCON_INT_F_EN | SAMSUNG_KEYIFCON_INT_R_EN;
    writel(val, keypad->base + SAMSUNG_KEYIFCON);

    /* KEYIFCOL reg clear. */
    writel(0, keypad->base + SAMSUNG_KEYIFCOL);

    pm_runtime_put(&keypad->pdev->dev);
}

static void samsung_keypad_stop(struct samsung_keypad *keypad)
{
    unsigned int val;

    pm_runtime_get_sync(&keypad->pdev->dev);

    /* Signal IRQ thread to stop polling and disable the handler. */
    keypad->stopped = true;
    wake_up(&keypad->wait);
    disable_irq(keypad->irq);

    /* Clear interrupt. */
    writel(~0x0, keypad->base + SAMSUNG_KEYIFSTSCLR);

    /* Disable interrupt bits. */
    val = readl(keypad->base + SAMSUNG_KEYIFCON);
    val &= ~(SAMSUNG_KEYIFCON_INT_F_EN | SAMSUNG_KEYIFCON_INT_R_EN);
    writel(val, keypad->base + SAMSUNG_KEYIFCON);

    clk_disable(keypad->clk);

    /*
     * Now that chip should not generate interrupts we can safely
     * re-enable the handler.
     */
    enable_irq(keypad->irq);

    pm_runtime_put(&keypad->pdev->dev);
}

static int samsung_keypad_open(struct input_dev *input_dev)
{
    struct samsung_keypad *keypad = input_get_drvdata(input_dev);

    samsung_keypad_start(keypad);

    return 0;
}

static void samsung_keypad_close(struct input_dev *input_dev)
{
    struct samsung_keypad *keypad = input_get_drvdata(input_dev);

    samsung_keypad_stop(keypad);
}

#ifdef CONFIG_OF
static struct samsung_keypad_platdata *samsung_keypad_parse_dt(
                struct device *dev)
{
    struct samsung_keypad_platdata *pdata;
    struct matrix_keymap_data *keymap_data;
    uint32_t *keymap, num_rows = 0, num_cols = 0;
    struct device_node *np = dev->of_node, *key_np;
    unsigned int key_count;

    pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
    if (!pdata) {
        dev_err(dev, "could not allocate memory for platform data\n");
        return NULL;
    }

    of_property_read_u32(np, "samsung,keypad-num-rows", &num_rows);
    of_property_read_u32(np, "samsung,keypad-num-columns", &num_cols);
    if (!num_rows || !num_cols) {
        dev_err(dev, "number of keypad rows/columns not specified\n");
        return NULL;
    }
    pdata->rows = num_rows;
    pdata->cols = num_cols;

    keymap_data = devm_kzalloc(dev, sizeof(*keymap_data), GFP_KERNEL);
    if (!keymap_data) {
        dev_err(dev, "could not allocate memory for keymap data\n");
        return NULL;
    }
    pdata->keymap_data = keymap_data;

    key_count = of_get_child_count(np);
    keymap_data->keymap_size = key_count;
    keymap = devm_kzalloc(dev, sizeof(uint32_t) * key_count, GFP_KERNEL);
    if (!keymap) {
        dev_err(dev, "could not allocate memory for keymap\n");
        return NULL;
    }
    keymap_data->keymap = keymap;

    for_each_child_of_node(np, key_np) {
        u32 row, col, key_code;
        of_property_read_u32(key_np, "keypad,row", &row);
        of_property_read_u32(key_np, "keypad,column", &col);
        of_property_read_u32(key_np, "linux,code", &key_code);
        *keymap++ = KEY(row, col, key_code);
    }

    if (of_get_property(np, "linux,input-no-autorepeat", NULL))
        pdata->no_autorepeat = true;
    if (of_get_property(np, "linux,input-wakeup", NULL))
        pdata->wakeup = true;

    return pdata;
}

static void samsung_keypad_parse_dt_gpio(struct device *dev,
                struct samsung_keypad *keypad)
{
    struct device_node *np = dev->of_node;
    int gpio, ret, row, col;

    for (row = 0; row < keypad->rows; row++) {
        gpio = of_get_named_gpio(np, "row-gpios", row);
        keypad->row_gpios[row] = gpio;
        if (!gpio_is_valid(gpio)) {
            dev_err(dev, "keypad row[%d]: invalid gpio %d\n",
                    row, gpio);
            continue;
        }

        ret = gpio_request(gpio, "keypad-row");
        if (ret)
            dev_err(dev, "keypad row[%d] gpio request failed\n",
                    row);
    }

    for (col = 0; col < keypad->cols; col++) {
        gpio = of_get_named_gpio(np, "col-gpios", col);
        keypad->col_gpios[col] = gpio;
        if (!gpio_is_valid(gpio)) {
            dev_err(dev, "keypad column[%d]: invalid gpio %d\n",
                    col, gpio);
            continue;
        }

        ret = gpio_request(gpio, "keypad-col");
        if (ret)
            dev_err(dev, "keypad column[%d] gpio request failed\n",
                    col);
    }
}

static void samsung_keypad_dt_gpio_free(struct samsung_keypad *keypad)
{
    int cnt;

    for (cnt = 0; cnt < keypad->rows; cnt++)
        if (gpio_is_valid(keypad->row_gpios[cnt]))
            gpio_free(keypad->row_gpios[cnt]);

    for (cnt = 0; cnt < keypad->cols; cnt++)
        if (gpio_is_valid(keypad->col_gpios[cnt]))
            gpio_free(keypad->col_gpios[cnt]);
}
#else
static
struct samsung_keypad_platdata *samsung_keypad_parse_dt(struct device *dev)
{
    return NULL;
}

static void samsung_keypad_dt_gpio_free(struct samsung_keypad *keypad)
{
}
#endif

static int __devinit samsung_keypad_probe(struct platform_device *pdev)
{
    const struct samsung_keypad_platdata *pdata;
    const struct matrix_keymap_data *keymap_data;
    struct samsung_keypad *keypad;
    struct resource *res;
    struct input_dev *input_dev;
    unsigned int row_shift;
    unsigned int keymap_size;
    int error;

    if (pdev->dev.of_node)
        pdata = samsung_keypad_parse_dt(&pdev->dev);
    else
        pdata = pdev->dev.platform_data;
    if (!pdata) {
        dev_err(&pdev->dev, "no platform data defined\n");
        return -EINVAL;
    }

    keymap_data = pdata->keymap_data;
    if (!keymap_data) {
        dev_err(&pdev->dev, "no keymap data defined\n");
        return -EINVAL;
    }

    if (!pdata->rows || pdata->rows > SAMSUNG_MAX_ROWS)
        return -EINVAL;

    if (!pdata->cols || pdata->cols > SAMSUNG_MAX_COLS)
        return -EINVAL;

    /* initialize the gpio */
    if (pdata->cfg_gpio)
        pdata->cfg_gpio(pdata->rows, pdata->cols);

    row_shift = get_count_order(pdata->cols);
    keymap_size = (pdata->rows << row_shift) * sizeof(keypad->keycodes[0]);

    keypad = kzalloc(sizeof(*keypad) + keymap_size, GFP_KERNEL);
    input_dev = input_allocate_device();
    if (!keypad || !input_dev) {
        error = -ENOMEM;
        goto err_free_mem;
    }

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res) {
        error = -ENODEV;
        goto err_free_mem;
    }

    keypad->base = ioremap(res->start, resource_size(res));
    if (!keypad->base) {
        error = -EBUSY;
        goto err_free_mem;
    }

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

    error = clk_prepare(keypad->clk);
    if (error) {
        dev_err(&pdev->dev, "keypad clock prepare failed\n");
        goto err_put_clk;
    }

    keypad->input_dev = input_dev;
    keypad->pdev = pdev;
    keypad->row_shift = row_shift;
    keypad->rows = pdata->rows;
    keypad->cols = pdata->cols;
    keypad->stopped = true;
    init_waitqueue_head(&keypad->wait);

    if (pdev->dev.of_node) {
#ifdef CONFIG_OF
        samsung_keypad_parse_dt_gpio(&pdev->dev, keypad);
        keypad->type = of_device_is_compatible(pdev->dev.of_node,
                    "samsung,s5pv210-keypad");
#endif
    } else {
        keypad->type = platform_get_device_id(pdev)->driver_data;
    }

    input_dev->name = pdev->name;
    input_dev->id.bustype = BUS_HOST;
    input_dev->dev.parent = &pdev->dev;

    input_dev->open = samsung_keypad_open;
    input_dev->close = samsung_keypad_close;

    error = matrix_keypad_build_keymap(keymap_data, NULL,
                       pdata->rows, pdata->cols,
                       keypad->keycodes, input_dev);
    if (error) {
        dev_err(&pdev->dev, "failed to build keymap\n");
        goto err_unprepare_clk;
    }

    input_set_capability(input_dev, EV_MSC, MSC_SCAN);
    if (!pdata->no_autorepeat)
        __set_bit(EV_REP, input_dev->evbit);

    input_set_drvdata(input_dev, keypad);

    keypad->irq = platform_get_irq(pdev, 0);
    if (keypad->irq < 0) {
        error = keypad->irq;
        goto err_put_clk;
    }

    error = request_threaded_irq(keypad->irq, NULL, samsung_keypad_irq,
            IRQF_ONESHOT, dev_name(&pdev->dev), keypad);
    if (error) {
        dev_err(&pdev->dev, "failed to register keypad interrupt\n");
        goto err_put_clk;
    }

    device_init_wakeup(&pdev->dev, pdata->wakeup);
    platform_set_drvdata(pdev, keypad);
    pm_runtime_enable(&pdev->dev);

    error = input_register_device(keypad->input_dev);
    if (error)
        goto err_free_irq;

    if (pdev->dev.of_node) {
        devm_kfree(&pdev->dev, (void *)pdata->keymap_data->keymap);
        devm_kfree(&pdev->dev, (void *)pdata->keymap_data);
        devm_kfree(&pdev->dev, (void *)pdata);
    }
    return 0;

err_free_irq:
    free_irq(keypad->irq, keypad);
    pm_runtime_disable(&pdev->dev);
    device_init_wakeup(&pdev->dev, 0);
    platform_set_drvdata(pdev, NULL);
err_unprepare_clk:
    clk_unprepare(keypad->clk);
err_put_clk:
    clk_put(keypad->clk);
    samsung_keypad_dt_gpio_free(keypad);
err_unmap_base:
    iounmap(keypad->base);
err_free_mem:
    input_free_device(input_dev);
    kfree(keypad);

    return error;
}

static int __devexit samsung_keypad_remove(struct platform_device *pdev)
{
    struct samsung_keypad *keypad = platform_get_drvdata(pdev);

    pm_runtime_disable(&pdev->dev);
    device_init_wakeup(&pdev->dev, 0);
    platform_set_drvdata(pdev, NULL);

    input_unregister_device(keypad->input_dev);

    /*
     * It is safe to free IRQ after unregistering device because
     * samsung_keypad_close will shut off interrupts.
     */
    free_irq(keypad->irq, keypad);

    clk_unprepare(keypad->clk);
    clk_put(keypad->clk);
    samsung_keypad_dt_gpio_free(keypad);

    iounmap(keypad->base);
    kfree(keypad);

    return 0;
}

#ifdef CONFIG_PM_RUNTIME
static int samsung_keypad_runtime_suspend(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct samsung_keypad *keypad = platform_get_drvdata(pdev);
    unsigned int val;
    int error;

    if (keypad->stopped)
        return 0;

    /* This may fail on some SoCs due to lack of controller support */
    error = enable_irq_wake(keypad->irq);
    if (!error)
        keypad->wake_enabled = true;

    val = readl(keypad->base + SAMSUNG_KEYIFCON);
    val |= SAMSUNG_KEYIFCON_WAKEUPEN;
    writel(val, keypad->base + SAMSUNG_KEYIFCON);

    clk_disable(keypad->clk);

    return 0;
}

static int samsung_keypad_runtime_resume(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct samsung_keypad *keypad = platform_get_drvdata(pdev);
    unsigned int val;

    if (keypad->stopped)
        return 0;

    clk_enable(keypad->clk);

    val = readl(keypad->base + SAMSUNG_KEYIFCON);
    val &= ~SAMSUNG_KEYIFCON_WAKEUPEN;
    writel(val, keypad->base + SAMSUNG_KEYIFCON);

    if (keypad->wake_enabled)
        disable_irq_wake(keypad->irq);

    return 0;
}
#endif

#ifdef CONFIG_PM_SLEEP
static void samsung_keypad_toggle_wakeup(struct samsung_keypad *keypad,
                     bool enable)
{
    unsigned int val;

    clk_enable(keypad->clk);

    val = readl(keypad->base + SAMSUNG_KEYIFCON);
    if (enable) {
        val |= SAMSUNG_KEYIFCON_WAKEUPEN;
        if (device_may_wakeup(&keypad->pdev->dev))
            enable_irq_wake(keypad->irq);
    } else {
        val &= ~SAMSUNG_KEYIFCON_WAKEUPEN;
        if (device_may_wakeup(&keypad->pdev->dev))
            disable_irq_wake(keypad->irq);
    }
    writel(val, keypad->base + SAMSUNG_KEYIFCON);

    clk_disable(keypad->clk);
}

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

    mutex_lock(&input_dev->mutex);

    if (input_dev->users)
        samsung_keypad_stop(keypad);

    samsung_keypad_toggle_wakeup(keypad, true);

    mutex_unlock(&input_dev->mutex);

    return 0;
}

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

    mutex_lock(&input_dev->mutex);

    samsung_keypad_toggle_wakeup(keypad, false);

    if (input_dev->users)
        samsung_keypad_start(keypad);

    mutex_unlock(&input_dev->mutex);

    return 0;
}
#endif

static const struct dev_pm_ops samsung_keypad_pm_ops = {
    SET_SYSTEM_SLEEP_PM_OPS(samsung_keypad_suspend, samsung_keypad_resume)
    SET_RUNTIME_PM_OPS(samsung_keypad_runtime_suspend,
               samsung_keypad_runtime_resume, NULL)
};

#ifdef CONFIG_OF
static const struct of_device_id samsung_keypad_dt_match[] = {
    { .compatible = "samsung,s3c6410-keypad" },
    { .compatible = "samsung,s5pv210-keypad" },
    {},
};
MODULE_DEVICE_TABLE(of, samsung_keypad_dt_match);
#endif

static struct platform_device_id samsung_keypad_driver_ids[] = {
    {
        .name       = "samsung-keypad",
        .driver_data    = KEYPAD_TYPE_SAMSUNG,
    }, {
        .name       = "s5pv210-keypad",
        .driver_data    = KEYPAD_TYPE_S5PV210,
    },
    { },
};
MODULE_DEVICE_TABLE(platform, samsung_keypad_driver_ids);

static struct platform_driver samsung_keypad_driver = {
    .probe      = samsung_keypad_probe,
    .remove     = __devexit_p(samsung_keypad_remove),
    .driver     = {
        .name   = "samsung-keypad",
        .owner  = THIS_MODULE,
        .of_match_table = of_match_ptr(samsung_keypad_dt_match),
        .pm = &samsung_keypad_pm_ops,
    },
    .id_table   = samsung_keypad_driver_ids,
};
module_platform_driver(samsung_keypad_driver);

MODULE_DESCRIPTION("Samsung keypad driver");
MODULE_AUTHOR("Joonyoung Shim <[email protected]>");
MODULE_AUTHOR("Donghwa Lee <[email protected]>");
MODULE_LICENSE("GPL");