locomokbd.c

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/*
 * LoCoMo keyboard driver for Linux-based ARM PDAs:
 *  - SHARP Zaurus Collie (SL-5500)
 *  - SHARP Zaurus Poodle (SL-5600)
 *
 * Copyright (c) 2005 John Lenz
 * Based on from xtkbd.c
 *
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>

#include <asm/hardware/locomo.h>
#include <asm/irq.h>

MODULE_AUTHOR("John Lenz <[email protected]>");
MODULE_DESCRIPTION("LoCoMo keyboard driver");
MODULE_LICENSE("GPL");

#define LOCOMOKBD_NUMKEYS   128

#define KEY_ACTIVITY        KEY_F16
#define KEY_CONTACT     KEY_F18
#define KEY_CENTER      KEY_F15

static const unsigned char
locomokbd_keycode[LOCOMOKBD_NUMKEYS] __devinitconst = {
    0, KEY_ESC, KEY_ACTIVITY, 0, 0, 0, 0, 0, 0, 0,              /* 0 - 9 */
    0, 0, 0, 0, 0, 0, 0, KEY_MENU, KEY_HOME, KEY_CONTACT,           /* 10 - 19 */
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,                       /* 20 - 29 */
    0, 0, 0, KEY_CENTER, 0, KEY_MAIL, 0, 0, 0, 0,               /* 30 - 39 */
    0, 0, 0, 0, 0, 0, 0, 0, 0, KEY_RIGHT,                   /* 40 - 49 */
    KEY_UP, KEY_LEFT, 0, 0, KEY_P, 0, KEY_O, KEY_I, KEY_Y, KEY_T,       /* 50 - 59 */
    KEY_E, KEY_W, 0, 0, 0, 0, KEY_DOWN, KEY_ENTER, 0, 0,            /* 60 - 69 */
    KEY_BACKSPACE, 0, KEY_L, KEY_U, KEY_H, KEY_R, KEY_D, KEY_Q, 0, 0,   /* 70 - 79 */
    0, 0, 0, 0, 0, 0, KEY_ENTER, KEY_RIGHTSHIFT, KEY_K, KEY_J,      /* 80 - 89 */
    KEY_G, KEY_F, KEY_X, KEY_S, 0, 0, 0, 0, 0, 0,               /* 90 - 99 */
    0, 0, KEY_DOT, 0, KEY_COMMA, KEY_N, KEY_B, KEY_C, KEY_Z, KEY_A,     /* 100 - 109 */
    KEY_LEFTSHIFT, KEY_TAB, KEY_LEFTCTRL, 0, 0, 0, 0, 0, 0, 0,      /* 110 - 119 */
    KEY_M, KEY_SPACE, KEY_V, KEY_APOSTROPHE, KEY_SLASH, 0, 0, 0     /* 120 - 128 */
};

#define KB_ROWS         16
#define KB_COLS         8
#define KB_ROWMASK(r)       (1 << (r))
#define SCANCODE(c,r)       ( ((c)<<4) + (r) + 1 )

#define KB_DELAY        8
#define SCAN_INTERVAL       (HZ/10)

struct locomokbd {
    unsigned char keycode[LOCOMOKBD_NUMKEYS];
    struct input_dev *input;
    char phys[32];

    unsigned long base;
    spinlock_t lock;

    struct timer_list timer;
    unsigned long suspend_jiffies;
    unsigned int count_cancel;
};

/* helper functions for reading the keyboard matrix */
static inline void locomokbd_charge_all(unsigned long membase)
{
    locomo_writel(0x00FF, membase + LOCOMO_KSC);
}

static inline void locomokbd_activate_all(unsigned long membase)
{
    unsigned long r;

    locomo_writel(0, membase + LOCOMO_KSC);
    r = locomo_readl(membase + LOCOMO_KIC);
    r &= 0xFEFF;
    locomo_writel(r, membase + LOCOMO_KIC);
}

static inline void locomokbd_activate_col(unsigned long membase, int col)
{
    unsigned short nset;
    unsigned short nbset;

    nset = 0xFF & ~(1 << col);
    nbset = (nset << 8) + nset;
    locomo_writel(nbset, membase + LOCOMO_KSC);
}

static inline void locomokbd_reset_col(unsigned long membase, int col)
{
    unsigned short nbset;

    nbset = ((0xFF & ~(1 << col)) << 8) + 0xFF;
    locomo_writel(nbset, membase + LOCOMO_KSC);
}

/*
 * The LoCoMo keyboard only generates interrupts when a key is pressed.
 * So when a key is pressed, we enable a timer.  This timer scans the
 * keyboard, and this is how we detect when the key is released.
 */

/* Scan the hardware keyboard and push any changes up through the input layer */
static void locomokbd_scankeyboard(struct locomokbd *locomokbd)
{
    unsigned int row, col, rowd;
    unsigned long flags;
    unsigned int num_pressed;
    unsigned long membase = locomokbd->base;

    spin_lock_irqsave(&locomokbd->lock, flags);

    locomokbd_charge_all(membase);

    num_pressed = 0;
    for (col = 0; col < KB_COLS; col++) {

        locomokbd_activate_col(membase, col);
        udelay(KB_DELAY);

        rowd = ~locomo_readl(membase + LOCOMO_KIB);
        for (row = 0; row < KB_ROWS; row++) {
            unsigned int scancode, pressed, key;

            scancode = SCANCODE(col, row);
            pressed = rowd & KB_ROWMASK(row);
            key = locomokbd->keycode[scancode];

            input_report_key(locomokbd->input, key, pressed);
            if (likely(!pressed))
                continue;

            num_pressed++;

            /* The "Cancel/ESC" key is labeled "On/Off" on
             * Collie and Poodle and should suspend the device
             * if it was pressed for more than a second. */
            if (unlikely(key == KEY_ESC)) {
                if (!time_after(jiffies,
                    locomokbd->suspend_jiffies + HZ))
                    continue;
                if (locomokbd->count_cancel++
                    != (HZ/SCAN_INTERVAL + 1))
                    continue;
                input_event(locomokbd->input, EV_PWR,
                    KEY_SUSPEND, 1);
                locomokbd->suspend_jiffies = jiffies;
            } else
                locomokbd->count_cancel = 0;
        }
        locomokbd_reset_col(membase, col);
    }
    locomokbd_activate_all(membase);

    input_sync(locomokbd->input);

    /* if any keys are pressed, enable the timer */
    if (num_pressed)
        mod_timer(&locomokbd->timer, jiffies + SCAN_INTERVAL);
    else
        locomokbd->count_cancel = 0;

    spin_unlock_irqrestore(&locomokbd->lock, flags);
}

/*
 * LoCoMo keyboard interrupt handler.
 */
static irqreturn_t locomokbd_interrupt(int irq, void *dev_id)
{
    struct locomokbd *locomokbd = dev_id;
    u16 r;

    r = locomo_readl(locomokbd->base + LOCOMO_KIC);
    if ((r & 0x0001) == 0)
        return IRQ_HANDLED;

    locomo_writel(r & ~0x0100, locomokbd->base + LOCOMO_KIC); /* Ack */

    udelay(100);

    locomokbd_scankeyboard(locomokbd);
    return IRQ_HANDLED;
}

/*
 * LoCoMo timer checking for released keys
 */
static void locomokbd_timer_callback(unsigned long data)
{
    struct locomokbd *locomokbd = (struct locomokbd *) data;

    locomokbd_scankeyboard(locomokbd);
}

static int locomokbd_open(struct input_dev *dev)
{
    struct locomokbd *locomokbd = input_get_drvdata(dev);
    u16 r;
    
    r = locomo_readl(locomokbd->base + LOCOMO_KIC) | 0x0010;
    locomo_writel(r, locomokbd->base + LOCOMO_KIC);
    return 0;
}

static void locomokbd_close(struct input_dev *dev)
{
    struct locomokbd *locomokbd = input_get_drvdata(dev);
    u16 r;
    
    r = locomo_readl(locomokbd->base + LOCOMO_KIC) & ~0x0010;
    locomo_writel(r, locomokbd->base + LOCOMO_KIC);
}

static int __devinit locomokbd_probe(struct locomo_dev *dev)
{
    struct locomokbd *locomokbd;
    struct input_dev *input_dev;
    int i, err;

    locomokbd = kzalloc(sizeof(struct locomokbd), GFP_KERNEL);
    input_dev = input_allocate_device();
    if (!locomokbd || !input_dev) {
        err = -ENOMEM;
        goto err_free_mem;
    }

    /* try and claim memory region */
    if (!request_mem_region((unsigned long) dev->mapbase,
                dev->length,
                LOCOMO_DRIVER_NAME(dev))) {
        err = -EBUSY;
        printk(KERN_ERR "locomokbd: Can't acquire access to io memory for keyboard\n");
        goto err_free_mem;
    }

    locomo_set_drvdata(dev, locomokbd);

    locomokbd->base = (unsigned long) dev->mapbase;

    spin_lock_init(&locomokbd->lock);

    init_timer(&locomokbd->timer);
    locomokbd->timer.function = locomokbd_timer_callback;
    locomokbd->timer.data = (unsigned long) locomokbd;

    locomokbd->suspend_jiffies = jiffies;

    locomokbd->input = input_dev;
    strcpy(locomokbd->phys, "locomokbd/input0");

    input_dev->name = "LoCoMo keyboard";
    input_dev->phys = locomokbd->phys;
    input_dev->id.bustype = BUS_HOST;
    input_dev->id.vendor = 0x0001;
    input_dev->id.product = 0x0001;
    input_dev->id.version = 0x0100;
    input_dev->open = locomokbd_open;
    input_dev->close = locomokbd_close;
    input_dev->dev.parent = &dev->dev;

    input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP) |
                BIT_MASK(EV_PWR);
    input_dev->keycode = locomokbd->keycode;
    input_dev->keycodesize = sizeof(locomokbd_keycode[0]);
    input_dev->keycodemax = ARRAY_SIZE(locomokbd_keycode);

    input_set_drvdata(input_dev, locomokbd);

    memcpy(locomokbd->keycode, locomokbd_keycode, sizeof(locomokbd->keycode));
    for (i = 0; i < LOCOMOKBD_NUMKEYS; i++)
        set_bit(locomokbd->keycode[i], input_dev->keybit);
    clear_bit(0, input_dev->keybit);

    /* attempt to get the interrupt */
    err = request_irq(dev->irq[0], locomokbd_interrupt, 0, "locomokbd", locomokbd);
    if (err) {
        printk(KERN_ERR "locomokbd: Can't get irq for keyboard\n");
        goto err_release_region;
    }

    err = input_register_device(locomokbd->input);
    if (err)
        goto err_free_irq;

    return 0;

 err_free_irq:
    free_irq(dev->irq[0], locomokbd);
 err_release_region:
    release_mem_region((unsigned long) dev->mapbase, dev->length);
    locomo_set_drvdata(dev, NULL);
 err_free_mem:
    input_free_device(input_dev);
    kfree(locomokbd);

    return err;
}

static int __devexit locomokbd_remove(struct locomo_dev *dev)
{
    struct locomokbd *locomokbd = locomo_get_drvdata(dev);

    free_irq(dev->irq[0], locomokbd);

    del_timer_sync(&locomokbd->timer);

    input_unregister_device(locomokbd->input);
    locomo_set_drvdata(dev, NULL);

    release_mem_region((unsigned long) dev->mapbase, dev->length);

    kfree(locomokbd);

    return 0;
}

static struct locomo_driver keyboard_driver = {
    .drv = {
        .name = "locomokbd"
    },
    .devid  = LOCOMO_DEVID_KEYBOARD,
    .probe  = locomokbd_probe,
    .remove = __devexit_p(locomokbd_remove),
};

static int __init locomokbd_init(void)
{
    return locomo_driver_register(&keyboard_driver);
}

static void __exit locomokbd_exit(void)
{
    locomo_driver_unregister(&keyboard_driver);
}

module_init(locomokbd_init);
module_exit(locomokbd_exit);