original_kernel/arch/m68k/mac/baboon.c

91 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Baboon Custom IC Management
*
* The Baboon custom IC controls the IDE, PCMCIA and media bay on the
* PowerBook 190. It multiplexes multiple interrupt sources onto the
* Nubus slot $C interrupt.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/irq.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/mac_baboon.h>
#include "mac.h"
int baboon_present;
static volatile struct baboon *baboon;
/*
* Baboon initialization.
*/
void __init baboon_init(void)
{
if (macintosh_config->ident != MAC_MODEL_PB190) {
baboon = NULL;
baboon_present = 0;
return;
}
baboon = (struct baboon *) BABOON_BASE;
baboon_present = 1;
pr_debug("Baboon detected at %p\n", baboon);
}
/*
* Baboon interrupt handler.
* XXX how do you clear a pending IRQ? is it even necessary?
*/
static void baboon_irq(struct irq_desc *desc)
{
short events, irq_bit;
int irq_num;
events = baboon->mb_ifr & 0x07;
irq_num = IRQ_BABOON_0;
irq_bit = 1;
do {
if (events & irq_bit) {
events &= ~irq_bit;
generic_handle_irq(irq_num);
}
++irq_num;
irq_bit <<= 1;
} while (events);
}
/*
* Register the Baboon interrupt dispatcher on nubus slot $C.
*/
void __init baboon_register_interrupts(void)
{
irq_set_chained_handler(IRQ_NUBUS_C, baboon_irq);
}
/*
* The means for masking individual Baboon interrupts remains a mystery.
* However, since we only use the IDE IRQ, we can just enable/disable all
* Baboon interrupts. If/when we handle more than one Baboon IRQ, we must
* either figure out how to mask them individually or else implement the
* same workaround that's used for NuBus slots (see nubus_disabled and
* via_nubus_irq_shutdown).
*/
void baboon_irq_enable(int irq)
{
mac_irq_enable(irq_get_irq_data(IRQ_NUBUS_C));
}
void baboon_irq_disable(int irq)
{
mac_irq_disable(irq_get_irq_data(IRQ_NUBUS_C));
}