xref: /openbmc/linux/arch/m68k/mac/baboon.c (revision d3964221)
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 }
100