LXR linux/arch/m68k/mac/psc.c

   1/*
   2 *      Apple Peripheral System Controller (PSC)
   3 *
   4 *      The PSC is used on the AV Macs to control IO functions not handled
   5 *      by the VIAs (Ethernet, DSP, SCC).
   6 *
   7 * TO DO:
   8 *
   9 * Try to figure out what's going on in pIFR5 and pIFR6. There seem to be
  10 * persisant interrupt conditions in those registers and I have no idea what
  11 * they are. Granted it doesn't affect since we're not enabling any interrupts
  12 * on those levels at the moment, but it would be nice to know. I have a feeling
  13 * they aren't actually interrupt lines but data lines (to the DSP?)
  14 */
  15
  16#include <linux/types.h>
  17#include <linux/kernel.h>
  18#include <linux/mm.h>
  19#include <linux/delay.h>
  20#include <linux/init.h>
  21#include <linux/irq.h>
  22
  23#include <asm/traps.h>
  24#include <asm/bootinfo.h>
  25#include <asm/macintosh.h>
  26#include <asm/macints.h>
  27#include <asm/mac_psc.h>
  28
  29#define DEBUG_PSC
  30
  31int psc_present;
  32volatile __u8 *psc;
  33
  34/*
  35 * Debugging dump, used in various places to see what's going on.
  36 */
  37
  38static void psc_debug_dump(void)
  39{
  40        int     i;
  41
  42        if (!psc_present) return;
  43        for (i = 0x30 ; i < 0x70 ; i += 0x10) {
  44                printk("PSC #%d:  IFR = 0x%02X IER = 0x%02X\n",
  45                        i >> 4,
  46                        (int) psc_read_byte(pIFRbase + i),
  47                        (int) psc_read_byte(pIERbase + i));
  48        }
  49}
  50
  51/*
  52 * Try to kill all DMA channels on the PSC. Not sure how this his
  53 * supposed to work; this is code lifted from macmace.c and then
  54 * expanded to cover what I think are the other 7 channels.
  55 */
  56
  57static void psc_dma_die_die_die(void)
  58{
  59        int i;
  60
  61        printk("Killing all PSC DMA channels...");
  62        for (i = 0 ; i < 9 ; i++) {
  63                psc_write_word(PSC_CTL_BASE + (i << 4), 0x8800);
  64                psc_write_word(PSC_CTL_BASE + (i << 4), 0x1000);
  65                psc_write_word(PSC_CMD_BASE + (i << 5), 0x1100);
  66                psc_write_word(PSC_CMD_BASE + (i << 5) + 0x10, 0x1100);
  67        }
  68        printk("done!\n");
  69}
  70
  71/*
  72 * Initialize the PSC. For now this just involves shutting down all
  73 * interrupt sources using the IERs.
  74 */
  75
  76void __init psc_init(void)
  77{
  78        int i;
  79
  80        if (macintosh_config->ident != MAC_MODEL_C660
  81         && macintosh_config->ident != MAC_MODEL_Q840)
  82        {
  83                psc = NULL;
  84                psc_present = 0;
  85                return;
  86        }
  87
  88        /*
  89         * The PSC is always at the same spot, but using psc
  90         * keeps things consistent with the psc_xxxx functions.
  91         */
  92
  93        psc = (void *) PSC_BASE;
  94        psc_present = 1;
  95
  96        printk("PSC detected at %p\n", psc);
  97
  98        psc_dma_die_die_die();
  99
 100#ifdef DEBUG_PSC
 101        psc_debug_dump();
 102#endif
 103        /*
 104         * Mask and clear all possible interrupts
 105         */
 106
 107        for (i = 0x30 ; i < 0x70 ; i += 0x10) {
 108                psc_write_byte(pIERbase + i, 0x0F);
 109                psc_write_byte(pIFRbase + i, 0x0F);
 110        }
 111}
 112
 113/*
 114 * PSC interrupt handler. It's a lot like the VIA interrupt handler.
 115 */
 116
 117static void psc_irq(unsigned int irq, struct irq_desc *desc)
 118{
 119        unsigned int offset = (unsigned int)irq_desc_get_handler_data(desc);
 120        int pIFR        = pIFRbase + offset;
 121        int pIER        = pIERbase + offset;
 122        int irq_num;
 123        unsigned char irq_bit, events;
 124
 125#ifdef DEBUG_IRQS
 126        printk("psc_irq: irq %u pIFR = 0x%02X pIER = 0x%02X\n",
 127                irq, (int) psc_read_byte(pIFR), (int) psc_read_byte(pIER));
 128#endif
 129
 130        events = psc_read_byte(pIFR) & psc_read_byte(pIER) & 0xF;
 131        if (!events)
 132                return;
 133
 134        irq_num = irq << 3;
 135        irq_bit = 1;
 136        do {
 137                if (events & irq_bit) {
 138                        psc_write_byte(pIFR, irq_bit);
 139                        generic_handle_irq(irq_num);
 140                }
 141                irq_num++;
 142                irq_bit <<= 1;
 143        } while (events >= irq_bit);
 144}
 145
 146/*
 147 * Register the PSC interrupt dispatchers for autovector interrupts 3-6.
 148 */
 149
 150void __init psc_register_interrupts(void)
 151{
 152        irq_set_chained_handler(IRQ_AUTO_3, psc_irq);
 153        irq_set_handler_data(IRQ_AUTO_3, (void *)0x30);
 154        irq_set_chained_handler(IRQ_AUTO_4, psc_irq);
 155        irq_set_handler_data(IRQ_AUTO_4, (void *)0x40);
 156        irq_set_chained_handler(IRQ_AUTO_5, psc_irq);
 157        irq_set_handler_data(IRQ_AUTO_5, (void *)0x50);
 158        irq_set_chained_handler(IRQ_AUTO_6, psc_irq);
 159        irq_set_handler_data(IRQ_AUTO_6, (void *)0x60);
 160}
 161
 162void psc_irq_enable(int irq) {
 163        int irq_src     = IRQ_SRC(irq);
 164        int irq_idx     = IRQ_IDX(irq);
 165        int pIER        = pIERbase + (irq_src << 4);
 166
 167#ifdef DEBUG_IRQUSE
 168        printk("psc_irq_enable(%d)\n", irq);
 169#endif
 170        psc_write_byte(pIER, (1 << irq_idx) | 0x80);
 171}
 172
 173void psc_irq_disable(int irq) {
 174        int irq_src     = IRQ_SRC(irq);
 175        int irq_idx     = IRQ_IDX(irq);
 176        int pIER        = pIERbase + (irq_src << 4);
 177
 178#ifdef DEBUG_IRQUSE
 179        printk("psc_irq_disable(%d)\n", irq);
 180#endif
 181        psc_write_byte(pIER, 1 << irq_idx);
 182}
 183