xref: /linux/arch/m68k/mac/baboon.c (revision 8e3ed5440b0c305dcd1d5fa7419bd8066d22ef42)
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 #include "mac.h"
19 
20 int baboon_present;
21 static volatile struct baboon *baboon;
22 
23 /*
24  * Baboon initialization.
25  */
26 
27 void __init baboon_init(void)
28 {
29 	if (macintosh_config->ident != MAC_MODEL_PB190) {
30 		baboon = NULL;
31 		baboon_present = 0;
32 		return;
33 	}
34 
35 	baboon = (struct baboon *) BABOON_BASE;
36 	baboon_present = 1;
37 
38 	pr_debug("Baboon detected at %p\n", baboon);
39 }
40 
41 /*
42  * Baboon interrupt handler.
43  * XXX how do you clear a pending IRQ? is it even necessary?
44  */
45 
46 static void baboon_irq(struct irq_desc *desc)
47 {
48 	short events, irq_bit;
49 	int irq_num;
50 
51 	events = baboon->mb_ifr & 0x07;
52 	irq_num = IRQ_BABOON_0;
53 	irq_bit = 1;
54 	do {
55 		if (events & irq_bit) {
56 			events &= ~irq_bit;
57 			generic_handle_irq(irq_num);
58 		}
59 		++irq_num;
60 		irq_bit <<= 1;
61 	} while (events);
62 }
63 
64 /*
65  * Register the Baboon interrupt dispatcher on nubus slot $C.
66  */
67 
68 void __init baboon_register_interrupts(void)
69 {
70 	irq_set_chained_handler(IRQ_NUBUS_C, baboon_irq);
71 }
72 
73 /*
74  * The means for masking individual Baboon interrupts remains a mystery.
75  * However, since we only use the IDE IRQ, we can just enable/disable all
76  * Baboon interrupts. If/when we handle more than one Baboon IRQ, we must
77  * either figure out how to mask them individually or else implement the
78  * same workaround that's used for NuBus slots (see nubus_disabled and
79  * via_nubus_irq_shutdown).
80  */
81 
82 void baboon_irq_enable(int irq)
83 {
84 	mac_irq_enable(irq_get_irq_data(IRQ_NUBUS_C));
85 }
86 
87 void baboon_irq_disable(int irq)
88 {
89 	mac_irq_disable(irq_get_irq_data(IRQ_NUBUS_C));
90 }
91