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