/*
* Apple Peripheral System Controller (PSC)
*
* The PSC is used on the AV Macs to control IO functions not handled
* by the VIAs (Ethernet, DSP, SCC).
*
* TO DO:
*
* Try to figure out what's going on in pIFR5 and pIFR6. There seem to be
* persisant interrupt conditions in those registers and I have no idea what
* they are. Granted it doesn't affect since we're not enabling any interrupts
* on those levels at the moment, but it would be nice to know. I have a feeling
* they aren't actually interrupt lines but data lines (to the DSP?)
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <asm/traps.h>
#include <asm/bootinfo.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/mac_psc.h>
#define DEBUG_PSC
int psc_present;
volatile __u8 *psc;
/*
* Debugging dump, used in various places to see what's going on.
*/
static void psc_debug_dump(void)
{
int i;
if (!psc_present) return;
for (i = 0x30 ; i < 0x70 ; i += 0x10) {
printk("PSC #%d: IFR = 0x%02X IER = 0x%02X\n",
i >> 4,
(int) psc_read_byte(pIFRbase + i),
(int) psc_read_byte(pIERbase + i));
}
}
/*
* Try to kill all DMA channels on the PSC. Not sure how this his
* supposed to work; this is code lifted from macmace.c and then
* expanded to cover what I think are the other 7 channels.
*/
static void psc_dma_die_die_die(void)
{
int i;
printk("Killing all PSC DMA channels...");
for (i = 0 ; i < 9 ; i++) {
psc_write_word(PSC_CTL_BASE + (i << 4), 0x8800);
psc_write_word(PSC_CTL_BASE + (i << 4), 0x1000);
psc_write_word(PSC_CMD_BASE + (i << 5), 0x1100);
psc_write_word(PSC_CMD_BASE + (i << 5) + 0x10, 0x1100);
}
printk("done!\n");
}
/*
* Initialize the PSC. For now this just involves shutting down all
* interrupt sources using the IERs.
*/
void __init psc_init(void)
{
int i;
if (macintosh_config->ident != MAC_MODEL_C660
&& macintosh_config->ident != MAC_MODEL_Q840)
{
psc = NULL;
psc_present = 0;
return;
}
/*
* The PSC is always at the same spot, but using psc
* keeps things consistent with the psc_xxxx functions.
*/
psc = (void *) PSC_BASE;
psc_present = 1;
printk("PSC detected at %p\n", psc);
psc_dma_die_die_die();
#ifdef DEBUG_PSC
psc_debug_dump();
#endif
/*
* Mask and clear all possible interrupts
*/
for (i = 0x30 ; i < 0x70 ; i += 0x10) {
psc_write_byte(pIERbase + i, 0x0F);
psc_write_byte(pIFRbase + i, 0x0F);
}
}
/*
* PSC interrupt handler. It's a lot like the VIA interrupt handler.
*/
static void psc_irq(unsigned int irq, struct irq_desc *desc)
{
unsigned int offset = (unsigned int)irq_desc_get_handler_data(desc);
int pIFR = pIFRbase + offset;
int pIER = pIERbase + offset;
int irq_num;
unsigned char irq_bit, events;
#ifdef DEBUG_IRQS
printk("psc_irq: irq %u pIFR = 0x%02X pIER = 0x%02X\n",
irq, (int) psc_read_byte(pIFR), (int) psc_read_byte(pIER));
#endif
events = psc_read_byte(pIFR) & psc_read_byte(pIER) & 0xF;
if (!events)
return;
irq_num = irq << 3;
irq_bit = 1;
do {
if (events & irq_bit) {
psc_write_byte(pIFR, irq_bit);
generic_handle_irq(irq_num);
}
irq_num++;
irq_bit <<= 1;
} while (events >= irq_bit);
}
/*
* Register the PSC interrupt dispatchers for autovector interrupts 3-6.
*/
void __init psc_register_interrupts(void)
{
irq_set_chained_handler(IRQ_AUTO_3, psc_irq);
irq_set_handler_data(IRQ_AUTO_3, (void *)0x30);
irq_set_chained_handler(IRQ_AUTO_4, psc_irq);
irq_set_handler_data(IRQ_AUTO_4, (void *)0x40);
irq_set_chained_handler(IRQ_AUTO_5, psc_irq);
irq_set_handler_data(IRQ_AUTO_5, (void *)0x50);
irq_set_chained_handler(IRQ_AUTO_6, psc_irq);
irq_set_handler_data(IRQ_AUTO_6, (void *)0x60);
}
void psc_irq_enable(int irq) {
int irq_src = IRQ_SRC(irq);
int irq_idx = IRQ_IDX(irq);
int pIER = pIERbase + (irq_src << 4);
#ifdef DEBUG_IRQUSE
printk("psc_irq_enable(%d)\n", irq);
#endif
psc_write_byte(pIER, (1 << irq_idx) | 0x80);
}
void psc_irq_disable(int irq) {
int irq_src = IRQ_SRC(irq);
int irq_idx = IRQ_IDX(irq);
int pIER = pIERbase + (irq_src << 4);
#ifdef DEBUG_IRQUSE
printk("psc_irq_disable(%d)\n", irq);
#endif
psc_write_byte(pIER, 1 << irq_idx);
}
