irq-mb93493.c

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/* irq-mb93493.c: MB93493 companion chip interrupt handler
 *
 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([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/ptrace.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/bitops.h>

#include <asm/io.h>
#include <asm/delay.h>
#include <asm/irq.h>
#include <asm/irc-regs.h>
#include <asm/mb93493-irqs.h>
#include <asm/mb93493-regs.h>

#define IRQ_ROUTE_ONE(X) (X##_ROUTE << (X - IRQ_BASE_MB93493))

#define IRQ_ROUTING                 \
    (IRQ_ROUTE_ONE(IRQ_MB93493_VDC)     |   \
     IRQ_ROUTE_ONE(IRQ_MB93493_VCC)     |   \
     IRQ_ROUTE_ONE(IRQ_MB93493_AUDIO_OUT)   |   \
     IRQ_ROUTE_ONE(IRQ_MB93493_I2C_0)   |   \
     IRQ_ROUTE_ONE(IRQ_MB93493_I2C_1)   |   \
     IRQ_ROUTE_ONE(IRQ_MB93493_USB)     |   \
     IRQ_ROUTE_ONE(IRQ_MB93493_LOCAL_BUS)   |   \
     IRQ_ROUTE_ONE(IRQ_MB93493_PCMCIA)  |   \
     IRQ_ROUTE_ONE(IRQ_MB93493_GPIO)    |   \
     IRQ_ROUTE_ONE(IRQ_MB93493_AUDIO_IN))

/*
 * daughter board PIC operations
 * - there is no way to ACK interrupts in the MB93493 chip
 */
static void frv_mb93493_mask(struct irq_data *d)
{
    uint32_t iqsr;
    volatile void *piqsr;

    if (IRQ_ROUTING & (1 << (d->irq - IRQ_BASE_MB93493)))
        piqsr = __addr_MB93493_IQSR(1);
    else
        piqsr = __addr_MB93493_IQSR(0);

    iqsr = readl(piqsr);
    iqsr &= ~(1 << (d->irq - IRQ_BASE_MB93493 + 16));
    writel(iqsr, piqsr);
}

static void frv_mb93493_ack(struct irq_data *d)
{
}

static void frv_mb93493_unmask(struct irq_data *d)
{
    uint32_t iqsr;
    volatile void *piqsr;

    if (IRQ_ROUTING & (1 << (d->irq - IRQ_BASE_MB93493)))
        piqsr = __addr_MB93493_IQSR(1);
    else
        piqsr = __addr_MB93493_IQSR(0);

    iqsr = readl(piqsr);
    iqsr |= 1 << (d->irq - IRQ_BASE_MB93493 + 16);
    writel(iqsr, piqsr);
}

static struct irq_chip frv_mb93493_pic = {
    .name       = "mb93093",
    .irq_ack    = frv_mb93493_ack,
    .irq_mask   = frv_mb93493_mask,
    .irq_mask_ack   = frv_mb93493_mask,
    .irq_unmask = frv_mb93493_unmask,
};

/*
 * MB93493 PIC interrupt handler
 */
static irqreturn_t mb93493_interrupt(int irq, void *_piqsr)
{
    volatile void *piqsr = _piqsr;
    uint32_t iqsr;

    iqsr = readl(piqsr);
    iqsr = iqsr & (iqsr >> 16) & 0xffff;

    /* poll all the triggered IRQs */
    while (iqsr) {
        int irq;

        asm("scan %1,gr0,%0" : "=r"(irq) : "r"(iqsr));
        irq = 31 - irq;
        iqsr &= ~(1 << irq);

        generic_handle_irq(IRQ_BASE_MB93493 + irq);
    }

    return IRQ_HANDLED;
}

/*
 * define an interrupt action for each MB93493 PIC output
 * - use dev_id to indicate the MB93493 PIC input to output mappings
 */
static struct irqaction mb93493_irq[2]  = {
    [0] = {
        .handler    = mb93493_interrupt,
        .flags      = IRQF_DISABLED | IRQF_SHARED,
        .name       = "mb93493.0",
        .dev_id     = (void *) __addr_MB93493_IQSR(0),
    },
    [1] = {
        .handler    = mb93493_interrupt,
        .flags      = IRQF_DISABLED | IRQF_SHARED,
        .name       = "mb93493.1",
        .dev_id     = (void *) __addr_MB93493_IQSR(1),
    }
};

/*
 * initialise the motherboard MB93493's PIC
 */
void __init mb93493_init(void)
{
    int irq;

    for (irq = IRQ_BASE_MB93493 + 0; irq <= IRQ_BASE_MB93493 + 10; irq++)
        irq_set_chip_and_handler(irq, &frv_mb93493_pic,
                     handle_edge_irq);

    /* the MB93493 drives external IRQ inputs on the CPU PIC */
    setup_irq(IRQ_CPU_MB93493_0, &mb93493_irq[0]);
    setup_irq(IRQ_CPU_MB93493_1, &mb93493_irq[1]);
}