sh_keysc.c

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/*
 * SuperH KEYSC Keypad Driver
 *
 * Copyright (C) 2008 Magnus Damm
 *
 * Based on gpio_keys.c, Copyright 2005 Phil Blundell
 *
 * 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.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/input/sh_keysc.h>
#include <linux/bitmap.h>
#include <linux/pm_runtime.h>
#include <linux/io.h>
#include <linux/slab.h>

static const struct {
    unsigned char kymd, keyout, keyin;
} sh_keysc_mode[] = {
    [SH_KEYSC_MODE_1] = { 0, 6, 5 },
    [SH_KEYSC_MODE_2] = { 1, 5, 6 },
    [SH_KEYSC_MODE_3] = { 2, 4, 7 },
    [SH_KEYSC_MODE_4] = { 3, 6, 6 },
    [SH_KEYSC_MODE_5] = { 4, 6, 7 },
    [SH_KEYSC_MODE_6] = { 5, 8, 8 },
};

struct sh_keysc_priv {
    void __iomem *iomem_base;
    DECLARE_BITMAP(last_keys, SH_KEYSC_MAXKEYS);
    struct input_dev *input;
    struct sh_keysc_info pdata;
};

#define KYCR1 0
#define KYCR2 1
#define KYINDR 2
#define KYOUTDR 3

#define KYCR2_IRQ_LEVEL    0x10
#define KYCR2_IRQ_DISABLED 0x00

static unsigned long sh_keysc_read(struct sh_keysc_priv *p, int reg_nr)
{
    return ioread16(p->iomem_base + (reg_nr << 2));
}

static void sh_keysc_write(struct sh_keysc_priv *p, int reg_nr,
               unsigned long value)
{
    iowrite16(value, p->iomem_base + (reg_nr << 2));
}

static void sh_keysc_level_mode(struct sh_keysc_priv *p,
                unsigned long keys_set)
{
    struct sh_keysc_info *pdata = &p->pdata;

    sh_keysc_write(p, KYOUTDR, 0);
    sh_keysc_write(p, KYCR2, KYCR2_IRQ_LEVEL | (keys_set << 8));

    if (pdata->kycr2_delay)
        udelay(pdata->kycr2_delay);
}

static void sh_keysc_map_dbg(struct device *dev, unsigned long *map,
                 const char *str)
{
    int k;

    for (k = 0; k < BITS_TO_LONGS(SH_KEYSC_MAXKEYS); k++)
        dev_dbg(dev, "%s[%d] 0x%lx\n", str, k, map[k]);
}

static irqreturn_t sh_keysc_isr(int irq, void *dev_id)
{
    struct platform_device *pdev = dev_id;
    struct sh_keysc_priv *priv = platform_get_drvdata(pdev);
    struct sh_keysc_info *pdata = &priv->pdata;
    int keyout_nr = sh_keysc_mode[pdata->mode].keyout;
    int keyin_nr = sh_keysc_mode[pdata->mode].keyin;
    DECLARE_BITMAP(keys, SH_KEYSC_MAXKEYS);
    DECLARE_BITMAP(keys0, SH_KEYSC_MAXKEYS);
    DECLARE_BITMAP(keys1, SH_KEYSC_MAXKEYS);
    unsigned char keyin_set, tmp;
    int i, k, n;

    dev_dbg(&pdev->dev, "isr!\n");

    bitmap_fill(keys1, SH_KEYSC_MAXKEYS);
    bitmap_zero(keys0, SH_KEYSC_MAXKEYS);

    do {
        bitmap_zero(keys, SH_KEYSC_MAXKEYS);
        keyin_set = 0;

        sh_keysc_write(priv, KYCR2, KYCR2_IRQ_DISABLED);

        for (i = 0; i < keyout_nr; i++) {
            n = keyin_nr * i;

            /* drive one KEYOUT pin low, read KEYIN pins */
            sh_keysc_write(priv, KYOUTDR, 0xffff ^ (3 << (i * 2)));
            udelay(pdata->delay);
            tmp = sh_keysc_read(priv, KYINDR);

            /* set bit if key press has been detected */
            for (k = 0; k < keyin_nr; k++) {
                if (tmp & (1 << k))
                    __set_bit(n + k, keys);
            }

            /* keep track of which KEYIN bits that have been set */
            keyin_set |= tmp ^ ((1 << keyin_nr) - 1);
        }

        sh_keysc_level_mode(priv, keyin_set);

        bitmap_complement(keys, keys, SH_KEYSC_MAXKEYS);
        bitmap_and(keys1, keys1, keys, SH_KEYSC_MAXKEYS);
        bitmap_or(keys0, keys0, keys, SH_KEYSC_MAXKEYS);

        sh_keysc_map_dbg(&pdev->dev, keys, "keys");

    } while (sh_keysc_read(priv, KYCR2) & 0x01);

    sh_keysc_map_dbg(&pdev->dev, priv->last_keys, "last_keys");
    sh_keysc_map_dbg(&pdev->dev, keys0, "keys0");
    sh_keysc_map_dbg(&pdev->dev, keys1, "keys1");

    for (i = 0; i < SH_KEYSC_MAXKEYS; i++) {
        k = pdata->keycodes[i];
        if (!k)
            continue;

        if (test_bit(i, keys0) == test_bit(i, priv->last_keys))
            continue;

        if (test_bit(i, keys1) || test_bit(i, keys0)) {
            input_event(priv->input, EV_KEY, k, 1);
            __set_bit(i, priv->last_keys);
        }

        if (!test_bit(i, keys1)) {
            input_event(priv->input, EV_KEY, k, 0);
            __clear_bit(i, priv->last_keys);
        }

    }
    input_sync(priv->input);

    return IRQ_HANDLED;
}

static int __devinit sh_keysc_probe(struct platform_device *pdev)
{
    struct sh_keysc_priv *priv;
    struct sh_keysc_info *pdata;
    struct resource *res;
    struct input_dev *input;
    int i;
    int irq, error;

    if (!pdev->dev.platform_data) {
        dev_err(&pdev->dev, "no platform data defined\n");
        error = -EINVAL;
        goto err0;
    }

    error = -ENXIO;
    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (res == NULL) {
        dev_err(&pdev->dev, "failed to get I/O memory\n");
        goto err0;
    }

    irq = platform_get_irq(pdev, 0);
    if (irq < 0) {
        dev_err(&pdev->dev, "failed to get irq\n");
        goto err0;
    }

    priv = kzalloc(sizeof(*priv), GFP_KERNEL);
    if (priv == NULL) {
        dev_err(&pdev->dev, "failed to allocate driver data\n");
        error = -ENOMEM;
        goto err0;
    }

    platform_set_drvdata(pdev, priv);
    memcpy(&priv->pdata, pdev->dev.platform_data, sizeof(priv->pdata));
    pdata = &priv->pdata;

    priv->iomem_base = ioremap_nocache(res->start, resource_size(res));
    if (priv->iomem_base == NULL) {
        dev_err(&pdev->dev, "failed to remap I/O memory\n");
        error = -ENXIO;
        goto err1;
    }

    priv->input = input_allocate_device();
    if (!priv->input) {
        dev_err(&pdev->dev, "failed to allocate input device\n");
        error = -ENOMEM;
        goto err2;
    }

    input = priv->input;
    input->evbit[0] = BIT_MASK(EV_KEY);

    input->name = pdev->name;
    input->phys = "sh-keysc-keys/input0";
    input->dev.parent = &pdev->dev;

    input->id.bustype = BUS_HOST;
    input->id.vendor = 0x0001;
    input->id.product = 0x0001;
    input->id.version = 0x0100;

    input->keycode = pdata->keycodes;
    input->keycodesize = sizeof(pdata->keycodes[0]);
    input->keycodemax = ARRAY_SIZE(pdata->keycodes);

    error = request_threaded_irq(irq, NULL, sh_keysc_isr, IRQF_ONESHOT,
                     dev_name(&pdev->dev), pdev);
    if (error) {
        dev_err(&pdev->dev, "failed to request IRQ\n");
        goto err3;
    }

    for (i = 0; i < SH_KEYSC_MAXKEYS; i++)
        __set_bit(pdata->keycodes[i], input->keybit);
    __clear_bit(KEY_RESERVED, input->keybit);

    error = input_register_device(input);
    if (error) {
        dev_err(&pdev->dev, "failed to register input device\n");
        goto err4;
    }

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

    sh_keysc_write(priv, KYCR1, (sh_keysc_mode[pdata->mode].kymd << 8) |
               pdata->scan_timing);
    sh_keysc_level_mode(priv, 0);

    device_init_wakeup(&pdev->dev, 1);

    return 0;

 err4:
    free_irq(irq, pdev);
 err3:
    input_free_device(input);
 err2:
    iounmap(priv->iomem_base);
 err1:
    platform_set_drvdata(pdev, NULL);
    kfree(priv);
 err0:
    return error;
}

static int __devexit sh_keysc_remove(struct platform_device *pdev)
{
    struct sh_keysc_priv *priv = platform_get_drvdata(pdev);

    sh_keysc_write(priv, KYCR2, KYCR2_IRQ_DISABLED);

    input_unregister_device(priv->input);
    free_irq(platform_get_irq(pdev, 0), pdev);
    iounmap(priv->iomem_base);

    pm_runtime_put_sync(&pdev->dev);
    pm_runtime_disable(&pdev->dev);

    platform_set_drvdata(pdev, NULL);
    kfree(priv);

    return 0;
}

#ifdef CONFIG_PM_SLEEP
static int sh_keysc_suspend(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct sh_keysc_priv *priv = platform_get_drvdata(pdev);
    int irq = platform_get_irq(pdev, 0);
    unsigned short value;

    value = sh_keysc_read(priv, KYCR1);

    if (device_may_wakeup(dev)) {
        sh_keysc_write(priv, KYCR1, value | 0x80);
        enable_irq_wake(irq);
    } else {
        sh_keysc_write(priv, KYCR1, value & ~0x80);
        pm_runtime_put_sync(dev);
    }

    return 0;
}

static int sh_keysc_resume(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    int irq = platform_get_irq(pdev, 0);

    if (device_may_wakeup(dev))
        disable_irq_wake(irq);
    else
        pm_runtime_get_sync(dev);

    return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(sh_keysc_dev_pm_ops,
             sh_keysc_suspend, sh_keysc_resume);

static struct platform_driver sh_keysc_device_driver = {
    .probe      = sh_keysc_probe,
    .remove     = __devexit_p(sh_keysc_remove),
    .driver     = {
        .name   = "sh_keysc",
        .pm = &sh_keysc_dev_pm_ops,
    }
};
module_platform_driver(sh_keysc_device_driver);

MODULE_AUTHOR("Magnus Damm");
MODULE_DESCRIPTION("SuperH KEYSC Keypad Driver");
MODULE_LICENSE("GPL");