auxio_64.c

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/* auxio.c: Probing for the Sparc AUXIO register at boot time.
 *
 * Copyright (C) 1996 David S. Miller ([email protected])
 *
 * Refactoring for unified NCR/PCIO support 2002 Eric Brower ([email protected])
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/of_device.h>

#include <asm/prom.h>
#include <asm/io.h>
#include <asm/auxio.h>

void __iomem *auxio_register = NULL;
EXPORT_SYMBOL(auxio_register);

enum auxio_type {
    AUXIO_TYPE_NODEV,
    AUXIO_TYPE_SBUS,
    AUXIO_TYPE_EBUS
};

static enum auxio_type auxio_devtype = AUXIO_TYPE_NODEV;
static DEFINE_SPINLOCK(auxio_lock);

static void __auxio_rmw(u8 bits_on, u8 bits_off, int ebus)
{
    if (auxio_register) {
        unsigned long flags;
        u8 regval, newval;

        spin_lock_irqsave(&auxio_lock, flags);

        regval = (ebus ?
              (u8) readl(auxio_register) :
              sbus_readb(auxio_register));
        newval =  regval | bits_on;
        newval &= ~bits_off;
        if (!ebus)
            newval &= ~AUXIO_AUX1_MASK;
        if (ebus)
            writel((u32) newval, auxio_register);
        else
            sbus_writeb(newval, auxio_register);
        
        spin_unlock_irqrestore(&auxio_lock, flags);
    }
}

static void __auxio_set_bit(u8 bit, int on, int ebus)
{
    u8 bits_on = (ebus ? AUXIO_PCIO_LED : AUXIO_AUX1_LED);
    u8 bits_off = 0;

    if (!on) {
        u8 tmp = bits_off;
        bits_off = bits_on;
        bits_on = tmp;
    }
    __auxio_rmw(bits_on, bits_off, ebus);
}

void auxio_set_led(int on)
{
    int ebus = auxio_devtype == AUXIO_TYPE_EBUS;
    u8 bit;

    bit = (ebus ? AUXIO_PCIO_LED : AUXIO_AUX1_LED);
    __auxio_set_bit(bit, on, ebus);
}
EXPORT_SYMBOL(auxio_set_led);

static void __auxio_sbus_set_lte(int on)
{
    __auxio_set_bit(AUXIO_AUX1_LTE, on, 0);
}

void auxio_set_lte(int on)
{
    switch(auxio_devtype) {
    case AUXIO_TYPE_SBUS:
        __auxio_sbus_set_lte(on);
        break;
    case AUXIO_TYPE_EBUS:
        /* FALL-THROUGH */
    default:
        break;
    }
}
EXPORT_SYMBOL(auxio_set_lte);

static const struct of_device_id auxio_match[] = {
    {
        .name = "auxio",
    },
    {},
};

MODULE_DEVICE_TABLE(of, auxio_match);

static int __devinit auxio_probe(struct platform_device *dev)
{
    struct device_node *dp = dev->dev.of_node;
    unsigned long size;

    if (!strcmp(dp->parent->name, "ebus")) {
        auxio_devtype = AUXIO_TYPE_EBUS;
        size = sizeof(u32);
    } else if (!strcmp(dp->parent->name, "sbus")) {
        auxio_devtype = AUXIO_TYPE_SBUS;
        size = 1;
    } else {
        printk("auxio: Unknown parent bus type [%s]\n",
               dp->parent->name);
        return -ENODEV;
    }
    auxio_register = of_ioremap(&dev->resource[0], 0, size, "auxio");
    if (!auxio_register)
        return -ENODEV;

    printk(KERN_INFO "AUXIO: Found device at %s\n",
           dp->full_name);

    if (auxio_devtype == AUXIO_TYPE_EBUS)
        auxio_set_led(AUXIO_LED_ON);

    return 0;
}

static struct platform_driver auxio_driver = {
    .probe      = auxio_probe,
    .driver = {
        .name = "auxio",
        .owner = THIS_MODULE,
        .of_match_table = auxio_match,
    },
};

static int __init auxio_init(void)
{
    return platform_driver_register(&auxio_driver);
}

/* Must be after subsys_initcall() so that busses are probed.  Must
 * be before device_initcall() because things like the floppy driver
 * need to use the AUXIO register.
 */
fs_initcall(auxio_init);