arch/m68k/mac/baboon.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Baboon Custom IC Management
   4  *
   5  * The Baboon custom IC controls the IDE, PCMCIA and media bay on the
   6  * PowerBook 190. It multiplexes multiple interrupt sources onto the
   7  * Nubus slot $C interrupt.
   8  */
   9
  10 #include <linux/types.h>
  11 #include <linux/kernel.h>
  12 #include <linux/irq.h>
  13
  14 #include <asm/macintosh.h>
  15 #include <asm/macints.h>
  16 #include <asm/mac_baboon.h>
  17
  18 int baboon_present;
  19 static volatile struct baboon *baboon;
  20
  21 #if 0
  22 extern int macide_ack_intr(struct ata_channel *);
  23 #endif
  24
  25 /*
  26  * Baboon initialization.
  27  */
  28
  29 void __init baboon_init(void)
  30 {
  31         if (macintosh_config->ident != MAC_MODEL_PB190) {
  32                 baboon = NULL;
  33                 baboon_present = 0;
  34                 return;
  35         }
  36
  37         baboon = (struct baboon *) BABOON_BASE;
  38         baboon_present = 1;
  39
  40         pr_debug("Baboon detected at %p\n", baboon);
  41 }
  42
  43 /*
  44  * Baboon interrupt handler. This works a lot like a VIA.
  45  */
  46
  47 static void baboon_irq(struct irq_desc *desc)
  48 {
  49         int irq_bit, irq_num;
  50         unsigned char events;
  51
  52         events = baboon->mb_ifr & 0x07;
  53         if (!events)
  54                 return;
  55
  56         irq_num = IRQ_BABOON_0;
  57         irq_bit = 1;
  58         do {
  59                 if (events & irq_bit) {
  60                         baboon->mb_ifr &= ~irq_bit;
  61                         generic_handle_irq(irq_num);
  62                 }
  63                 irq_bit <<= 1;
  64                 irq_num++;
  65         } while(events >= irq_bit);
  66 #if 0
  67         if (baboon->mb_ifr & 0x02) macide_ack_intr(NULL);
  68         /* for now we need to smash all interrupts */
  69         baboon->mb_ifr &= ~events;
  70 #endif
  71 }
  72
  73 /*
  74  * Register the Baboon interrupt dispatcher on nubus slot $C.
  75  */
  76
  77 void __init baboon_register_interrupts(void)
  78 {
  79         irq_set_chained_handler(IRQ_NUBUS_C, baboon_irq);
  80 }
  81
  82 /*
  83  * The means for masking individual Baboon interrupts remains a mystery.
  84  * However, since we only use the IDE IRQ, we can just enable/disable all
  85  * Baboon interrupts. If/when we handle more than one Baboon IRQ, we must
  86  * either figure out how to mask them individually or else implement the
  87  * same workaround that's used for NuBus slots (see nubus_disabled and
  88  * via_nubus_irq_shutdown).
  89  */
  90
  91 void baboon_irq_enable(int irq)
  92 {
  93         mac_irq_enable(irq_get_irq_data(IRQ_NUBUS_C));
  94 }
  95
  96 void baboon_irq_disable(int irq)
  97 {
  98         mac_irq_disable(irq_get_irq_data(IRQ_NUBUS_C));
  99 }