ambakmi.c

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/*
 *  linux/drivers/input/serio/ambakmi.c
 *
 *  Copyright (C) 2000-2003 Deep Blue Solutions Ltd.
 *  Copyright (C) 2002 Russell King.
 *
 * 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/module.h>
#include <linux/init.h>
#include <linux/serio.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/amba/bus.h>
#include <linux/amba/kmi.h>
#include <linux/clk.h>

#include <asm/io.h>
#include <asm/irq.h>

#define KMI_BASE    (kmi->base)

struct amba_kmi_port {
    struct serio        *io;
    struct clk      *clk;
    void __iomem        *base;
    unsigned int        irq;
    unsigned int        divisor;
    unsigned int        open;
};

static irqreturn_t amba_kmi_int(int irq, void *dev_id)
{
    struct amba_kmi_port *kmi = dev_id;
    unsigned int status = readb(KMIIR);
    int handled = IRQ_NONE;

    while (status & KMIIR_RXINTR) {
        serio_interrupt(kmi->io, readb(KMIDATA), 0);
        status = readb(KMIIR);
        handled = IRQ_HANDLED;
    }

    return handled;
}

static int amba_kmi_write(struct serio *io, unsigned char val)
{
    struct amba_kmi_port *kmi = io->port_data;
    unsigned int timeleft = 10000; /* timeout in 100ms */

    while ((readb(KMISTAT) & KMISTAT_TXEMPTY) == 0 && --timeleft)
        udelay(10);

    if (timeleft)
        writeb(val, KMIDATA);

    return timeleft ? 0 : SERIO_TIMEOUT;
}

static int amba_kmi_open(struct serio *io)
{
    struct amba_kmi_port *kmi = io->port_data;
    unsigned int divisor;
    int ret;

    ret = clk_prepare_enable(kmi->clk);
    if (ret)
        goto out;

    divisor = clk_get_rate(kmi->clk) / 8000000 - 1;
    writeb(divisor, KMICLKDIV);
    writeb(KMICR_EN, KMICR);

    ret = request_irq(kmi->irq, amba_kmi_int, 0, "kmi-pl050", kmi);
    if (ret) {
        printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq);
        writeb(0, KMICR);
        goto clk_disable;
    }

    writeb(KMICR_EN | KMICR_RXINTREN, KMICR);

    return 0;

 clk_disable:
    clk_disable_unprepare(kmi->clk);
 out:
    return ret;
}

static void amba_kmi_close(struct serio *io)
{
    struct amba_kmi_port *kmi = io->port_data;

    writeb(0, KMICR);

    free_irq(kmi->irq, kmi);
    clk_disable_unprepare(kmi->clk);
}

static int __devinit amba_kmi_probe(struct amba_device *dev,
    const struct amba_id *id)
{
    struct amba_kmi_port *kmi;
    struct serio *io;
    int ret;

    ret = amba_request_regions(dev, NULL);
    if (ret)
        return ret;

    kmi = kzalloc(sizeof(struct amba_kmi_port), GFP_KERNEL);
    io = kzalloc(sizeof(struct serio), GFP_KERNEL);
    if (!kmi || !io) {
        ret = -ENOMEM;
        goto out;
    }


    io->id.type = SERIO_8042;
    io->write   = amba_kmi_write;
    io->open    = amba_kmi_open;
    io->close   = amba_kmi_close;
    strlcpy(io->name, dev_name(&dev->dev), sizeof(io->name));
    strlcpy(io->phys, dev_name(&dev->dev), sizeof(io->phys));
    io->port_data   = kmi;
    io->dev.parent  = &dev->dev;

    kmi->io     = io;
    kmi->base   = ioremap(dev->res.start, resource_size(&dev->res));
    if (!kmi->base) {
        ret = -ENOMEM;
        goto out;
    }

    kmi->clk = clk_get(&dev->dev, "KMIREFCLK");
    if (IS_ERR(kmi->clk)) {
        ret = PTR_ERR(kmi->clk);
        goto unmap;
    }

    kmi->irq = dev->irq[0];
    amba_set_drvdata(dev, kmi);

    serio_register_port(kmi->io);
    return 0;

 unmap:
    iounmap(kmi->base);
 out:
    kfree(kmi);
    kfree(io);
    amba_release_regions(dev);
    return ret;
}

static int __devexit amba_kmi_remove(struct amba_device *dev)
{
    struct amba_kmi_port *kmi = amba_get_drvdata(dev);

    amba_set_drvdata(dev, NULL);

    serio_unregister_port(kmi->io);
    clk_put(kmi->clk);
    iounmap(kmi->base);
    kfree(kmi);
    amba_release_regions(dev);
    return 0;
}

static int amba_kmi_resume(struct amba_device *dev)
{
    struct amba_kmi_port *kmi = amba_get_drvdata(dev);

    /* kick the serio layer to rescan this port */
    serio_reconnect(kmi->io);

    return 0;
}

static struct amba_id amba_kmi_idtable[] = {
    {
        .id = 0x00041050,
        .mask   = 0x000fffff,
    },
    { 0, 0 }
};

MODULE_DEVICE_TABLE(amba, amba_kmi_idtable);

static struct amba_driver ambakmi_driver = {
    .drv        = {
        .name   = "kmi-pl050",
        .owner  = THIS_MODULE,
    },
    .id_table   = amba_kmi_idtable,
    .probe      = amba_kmi_probe,
    .remove     = __devexit_p(amba_kmi_remove),
    .resume     = amba_kmi_resume,
};

module_amba_driver(ambakmi_driver);

MODULE_AUTHOR("Russell King <[email protected]>");
MODULE_DESCRIPTION("AMBA KMI controller driver");
MODULE_LICENSE("GPL");