1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Macintosh interrupts |
4 | * |
5 | * General design: |
6 | * In contrary to the Amiga and Atari platforms, the Mac hardware seems to |
7 | * exclusively use the autovector interrupts (the 'generic level0-level7' |
8 | * interrupts with exception vectors 0x19-0x1f). The following interrupt levels |
9 | * are used: |
10 | * 1 - VIA1 |
11 | * - slot 0: one second interrupt (CA2) |
12 | * - slot 1: VBlank (CA1) |
13 | * - slot 2: ADB data ready (SR full) |
14 | * - slot 3: ADB data (CB2) |
15 | * - slot 4: ADB clock (CB1) |
16 | * - slot 5: timer 2 |
17 | * - slot 6: timer 1 |
18 | * - slot 7: status of IRQ; signals 'any enabled int.' |
19 | * |
20 | * 2 - VIA2 or RBV |
21 | * - slot 0: SCSI DRQ (CA2) |
22 | * - slot 1: NUBUS IRQ (CA1) need to read port A to find which |
23 | * - slot 2: /EXP IRQ (only on IIci) |
24 | * - slot 3: SCSI IRQ (CB2) |
25 | * - slot 4: ASC IRQ (CB1) |
26 | * - slot 5: timer 2 (not on IIci) |
27 | * - slot 6: timer 1 (not on IIci) |
28 | * - slot 7: status of IRQ; signals 'any enabled int.' |
29 | * |
30 | * Levels 3-6 vary by machine type. For VIA or RBV Macintoshes: |
31 | * |
32 | * 3 - unused (?) |
33 | * |
34 | * 4 - SCC |
35 | * |
36 | * 5 - unused (?) |
37 | * [serial errors or special conditions seem to raise level 6 |
38 | * interrupts on some models (LC4xx?)] |
39 | * |
40 | * 6 - off switch (?) |
41 | * |
42 | * Machines with Quadra-like VIA hardware, except PSC and PMU machines, support |
43 | * an alternate interrupt mapping, as used by A/UX. It spreads ethernet and |
44 | * sound out to their own autovector IRQs and gives VIA1 a higher priority: |
45 | * |
46 | * 1 - unused (?) |
47 | * |
48 | * 3 - on-board SONIC |
49 | * |
50 | * 5 - Apple Sound Chip (ASC) |
51 | * |
52 | * 6 - VIA1 |
53 | * |
54 | * For OSS Macintoshes (IIfx only), we apply an interrupt mapping similar to |
55 | * the Quadra (A/UX) mapping: |
56 | * |
57 | * 1 - ISM IOP (ADB) |
58 | * |
59 | * 2 - SCSI |
60 | * |
61 | * 3 - NuBus |
62 | * |
63 | * 4 - SCC IOP |
64 | * |
65 | * 6 - VIA1 |
66 | * |
67 | * For PSC Macintoshes (660AV, 840AV): |
68 | * |
69 | * 3 - PSC level 3 |
70 | * - slot 0: MACE |
71 | * |
72 | * 4 - PSC level 4 |
73 | * - slot 1: SCC channel A interrupt |
74 | * - slot 2: SCC channel B interrupt |
75 | * - slot 3: MACE DMA |
76 | * |
77 | * 5 - PSC level 5 |
78 | * |
79 | * 6 - PSC level 6 |
80 | * |
81 | * Finally we have good 'ole level 7, the non-maskable interrupt: |
82 | * |
83 | * 7 - NMI (programmer's switch on the back of some Macs) |
84 | * Also RAM parity error on models which support it (IIc, IIfx?) |
85 | * |
86 | * The current interrupt logic looks something like this: |
87 | * |
88 | * - We install dispatchers for the autovector interrupts (1-7). These |
89 | * dispatchers are responsible for querying the hardware (the |
90 | * VIA/RBV/OSS/PSC chips) to determine the actual interrupt source. Using |
91 | * this information a machspec interrupt number is generated by placing the |
92 | * index of the interrupt hardware into the low three bits and the original |
93 | * autovector interrupt number in the upper 5 bits. The handlers for the |
94 | * resulting machspec interrupt are then called. |
95 | * |
96 | * - Nubus is a special case because its interrupts are hidden behind two |
97 | * layers of hardware. Nubus interrupts come in as index 1 on VIA #2, |
98 | * which translates to IRQ number 17. In this spot we install _another_ |
99 | * dispatcher. This dispatcher finds the interrupting slot number (9-F) and |
100 | * then forms a new machspec interrupt number as above with the slot number |
101 | * minus 9 in the low three bits and the pseudo-level 7 in the upper five |
102 | * bits. The handlers for this new machspec interrupt number are then |
103 | * called. This puts Nubus interrupts into the range 56-62. |
104 | * |
105 | * - The Baboon interrupts (used on some PowerBooks) are an even more special |
106 | * case. They're hidden behind the Nubus slot $C interrupt thus adding a |
107 | * third layer of indirection. Why oh why did the Apple engineers do that? |
108 | * |
109 | */ |
110 | |
111 | #include <linux/types.h> |
112 | #include <linux/kernel.h> |
113 | #include <linux/sched.h> |
114 | #include <linux/sched/debug.h> |
115 | #include <linux/interrupt.h> |
116 | #include <linux/irq.h> |
117 | #include <linux/delay.h> |
118 | |
119 | #include <asm/irq.h> |
120 | #include <asm/macintosh.h> |
121 | #include <asm/macints.h> |
122 | #include <asm/mac_via.h> |
123 | #include <asm/mac_psc.h> |
124 | #include <asm/mac_oss.h> |
125 | #include <asm/mac_iop.h> |
126 | #include <asm/mac_baboon.h> |
127 | #include <asm/hwtest.h> |
128 | #include <asm/irq_regs.h> |
129 | #include <asm/processor.h> |
130 | |
131 | static unsigned int mac_irq_startup(struct irq_data *); |
132 | static void mac_irq_shutdown(struct irq_data *); |
133 | |
134 | static struct irq_chip mac_irq_chip = { |
135 | .name = "mac" , |
136 | .irq_enable = mac_irq_enable, |
137 | .irq_disable = mac_irq_disable, |
138 | .irq_startup = mac_irq_startup, |
139 | .irq_shutdown = mac_irq_shutdown, |
140 | }; |
141 | |
142 | static irqreturn_t mac_nmi_handler(int irq, void *dev_id) |
143 | { |
144 | static volatile int in_nmi; |
145 | |
146 | if (in_nmi) |
147 | return IRQ_HANDLED; |
148 | in_nmi = 1; |
149 | |
150 | pr_info("Non-Maskable Interrupt\n" ); |
151 | show_registers(get_irq_regs()); |
152 | |
153 | in_nmi = 0; |
154 | return IRQ_HANDLED; |
155 | } |
156 | |
157 | void __init mac_init_IRQ(void) |
158 | { |
159 | m68k_setup_irq_controller(&mac_irq_chip, handle_simple_irq, IRQ_USER, |
160 | NUM_MAC_SOURCES - IRQ_USER); |
161 | |
162 | /* |
163 | * Now register the handlers for the master IRQ handlers |
164 | * at levels 1-7. Most of the work is done elsewhere. |
165 | */ |
166 | |
167 | if (oss_present) |
168 | oss_register_interrupts(); |
169 | else |
170 | via_register_interrupts(); |
171 | if (psc) |
172 | psc_register_interrupts(); |
173 | if (baboon_present) |
174 | baboon_register_interrupts(); |
175 | iop_register_interrupts(); |
176 | if (request_irq(irq: IRQ_AUTO_7, handler: mac_nmi_handler, flags: 0, name: "NMI" , |
177 | dev: mac_nmi_handler)) |
178 | pr_err("Couldn't register NMI\n" ); |
179 | } |
180 | |
181 | /* |
182 | * mac_irq_enable - enable an interrupt source |
183 | * mac_irq_disable - disable an interrupt source |
184 | * |
185 | * These routines are just dispatchers to the VIA/OSS/PSC routines. |
186 | */ |
187 | |
188 | void mac_irq_enable(struct irq_data *data) |
189 | { |
190 | int irq = data->irq; |
191 | int irq_src = IRQ_SRC(irq); |
192 | |
193 | switch(irq_src) { |
194 | case 1: |
195 | case 2: |
196 | case 7: |
197 | if (oss_present) |
198 | oss_irq_enable(irq); |
199 | else |
200 | via_irq_enable(irq); |
201 | break; |
202 | case 3: |
203 | case 4: |
204 | case 5: |
205 | case 6: |
206 | if (psc) |
207 | psc_irq_enable(irq); |
208 | else if (oss_present) |
209 | oss_irq_enable(irq); |
210 | break; |
211 | case 8: |
212 | if (baboon_present) |
213 | baboon_irq_enable(irq); |
214 | break; |
215 | } |
216 | } |
217 | |
218 | void mac_irq_disable(struct irq_data *data) |
219 | { |
220 | int irq = data->irq; |
221 | int irq_src = IRQ_SRC(irq); |
222 | |
223 | switch(irq_src) { |
224 | case 1: |
225 | case 2: |
226 | case 7: |
227 | if (oss_present) |
228 | oss_irq_disable(irq); |
229 | else |
230 | via_irq_disable(irq); |
231 | break; |
232 | case 3: |
233 | case 4: |
234 | case 5: |
235 | case 6: |
236 | if (psc) |
237 | psc_irq_disable(irq); |
238 | else if (oss_present) |
239 | oss_irq_disable(irq); |
240 | break; |
241 | case 8: |
242 | if (baboon_present) |
243 | baboon_irq_disable(irq); |
244 | break; |
245 | } |
246 | } |
247 | |
248 | static unsigned int mac_irq_startup(struct irq_data *data) |
249 | { |
250 | int irq = data->irq; |
251 | |
252 | if (IRQ_SRC(irq) == 7 && !oss_present) |
253 | via_nubus_irq_startup(irq); |
254 | else |
255 | mac_irq_enable(data); |
256 | |
257 | return 0; |
258 | } |
259 | |
260 | static void mac_irq_shutdown(struct irq_data *data) |
261 | { |
262 | int irq = data->irq; |
263 | |
264 | if (IRQ_SRC(irq) == 7 && !oss_present) |
265 | via_nubus_irq_shutdown(irq); |
266 | else |
267 | mac_irq_disable(data); |
268 | } |
269 | |