1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
/*
* OSS handling
* Written by Joshua M. Thompson (funaho@jurai.org)
*
*
* This chip is used in the IIfx in place of VIA #2. It acts like a fancy
* VIA chip with prorammable interrupt levels.
*
* 990502 (jmt) - Major rewrite for new interrupt architecture as well as some
* recent insights into OSS operational details.
* 990610 (jmt) - Now taking full advantage of the OSS. Interrupts are mapped
* to mostly match the A/UX interrupt scheme supported on the
* VIA side. Also added support for enabling the ISM irq again
* since we now have a functional IOP manager.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <asm/bootinfo.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/mac_via.h>
#include <asm/mac_oss.h>
int oss_present;
volatile struct mac_oss *oss;
extern void via1_irq(unsigned int irq, struct irq_desc *desc);
/*
* Initialize the OSS
*
* The OSS "detection" code is actually in via_init() which is always called
* before us. Thus we can count on oss_present being valid on entry.
*/
void __init oss_init(void)
{
int i;
if (!oss_present) return;
oss = (struct mac_oss *) OSS_BASE;
/* Disable all interrupts. Unlike a VIA it looks like we */
/* do this by setting the source's interrupt level to zero. */
for (i = 0; i <= OSS_NUM_SOURCES; i++) {
oss->irq_level[i] = OSS_IRQLEV_DISABLED;
}
/* If we disable VIA1 here, we never really handle it... */
oss->irq_level[OSS_VIA1] = OSS_IRQLEV_VIA1;
}
/*
* Initialize OSS for Nubus access
*/
void __init oss_nubus_init(void)
{
}
/*
* Handle miscellaneous OSS interrupts. Right now that's just sound
* and SCSI; everything else is routed to its own autovector IRQ.
*/
static void oss_irq(unsigned int irq, struct irq_desc *desc)
{
int events;
events = oss->irq_pending & (OSS_IP_SOUND|OSS_IP_SCSI);
if (!events)
return;
#ifdef DEBUG_IRQS
if ((console_loglevel == 10) && !(events & OSS_IP_SCSI)) {
printk("oss_irq: irq %u events = 0x%04X\n", irq,
(int) oss->irq_pending);
}
#endif
/* FIXME: how do you clear a pending IRQ? */
if (events & OSS_IP_SOUND) {
oss->irq_pending &= ~OSS_IP_SOUND;
/* FIXME: call sound handler */
} else if (events & OSS_IP_SCSI) {
oss->irq_pending &= ~OSS_IP_SCSI;
generic_handle_irq(IRQ_MAC_SCSI);
} else {
/* FIXME: error check here? */
}
}
/*
* Nubus IRQ handler, OSS style
*
* Unlike the VIA/RBV this is on its own autovector interrupt level.
*/
static void oss_nubus_irq(unsigned int irq, struct irq_desc *desc)
{
int events, irq_bit, i;
events = oss->irq_pending & OSS_IP_NUBUS;
if (!events)
return;
#ifdef DEBUG_NUBUS_INT
if (console_loglevel > 7) {
printk("oss_nubus_irq: events = 0x%04X\n", events);
}
#endif
/* There are only six slots on the OSS, not seven */
i = 6;
irq_bit = 0x40;
do {
--i;
irq_bit >>= 1;
if (events & irq_bit) {
oss->irq_pending &= ~irq_bit;
generic_handle_irq(NUBUS_SOURCE_BASE + i);
}
} while(events & (irq_bit - 1));
}
/*
* Register the OSS and NuBus interrupt dispatchers.
*/
void __init oss_register_interrupts(void)
{
irq_set_chained_handler(OSS_IRQLEV_SCSI, oss_irq);
irq_set_chained_handler(OSS_IRQLEV_NUBUS, oss_nubus_irq);
irq_set_chained_handler(OSS_IRQLEV_SOUND, oss_irq);
irq_set_chained_handler(OSS_IRQLEV_VIA1, via1_irq);
}
/*
* Enable an OSS interrupt
*
* It looks messy but it's rather straightforward. The switch() statement
* just maps the machspec interrupt numbers to the right OSS interrupt
* source (if the OSS handles that interrupt) and then sets the interrupt
* level for that source to nonzero, thus enabling the interrupt.
*/
void oss_irq_enable(int irq) {
#ifdef DEBUG_IRQUSE
printk("oss_irq_enable(%d)\n", irq);
#endif
switch(irq) {
case IRQ_MAC_SCC:
oss->irq_level[OSS_IOPSCC] = OSS_IRQLEV_IOPSCC;
break;
case IRQ_MAC_ADB:
oss->irq_level[OSS_IOPISM] = OSS_IRQLEV_IOPISM;
break;
case IRQ_MAC_SCSI:
oss->irq_level[OSS_SCSI] = OSS_IRQLEV_SCSI;
break;
case IRQ_NUBUS_9:
case IRQ_NUBUS_A:
case IRQ_NUBUS_B:
case IRQ_NUBUS_C:
case IRQ_NUBUS_D:
case IRQ_NUBUS_E:
irq -= NUBUS_SOURCE_BASE;
oss->irq_level[irq] = OSS_IRQLEV_NUBUS;
break;
#ifdef DEBUG_IRQUSE
default:
printk("%s unknown irq %d\n", __func__, irq);
break;
#endif
}
}
/*
* Disable an OSS interrupt
*
* Same as above except we set the source's interrupt level to zero,
* to disable the interrupt.
*/
void oss_irq_disable(int irq) {
#ifdef DEBUG_IRQUSE
printk("oss_irq_disable(%d)\n", irq);
#endif
switch(irq) {
case IRQ_MAC_SCC:
oss->irq_level[OSS_IOPSCC] = OSS_IRQLEV_DISABLED;
break;
case IRQ_MAC_ADB:
oss->irq_level[OSS_IOPISM] = OSS_IRQLEV_DISABLED;
break;
case IRQ_MAC_SCSI:
oss->irq_level[OSS_SCSI] = OSS_IRQLEV_DISABLED;
break;
case IRQ_NUBUS_9:
case IRQ_NUBUS_A:
case IRQ_NUBUS_B:
case IRQ_NUBUS_C:
case IRQ_NUBUS_D:
case IRQ_NUBUS_E:
irq -= NUBUS_SOURCE_BASE;
oss->irq_level[irq] = OSS_IRQLEV_DISABLED;
break;
#ifdef DEBUG_IRQUSE
default:
printk("%s unknown irq %d\n", __func__, irq);
break;
#endif
}
}
|
