1 /*
2 * arch/m68k/q40/q40ints.c
3 *
4 * Copyright (C) 1999,2001 Richard Zidlicky
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file COPYING in the main directory of this archive
8 * for more details.
9 *
10 * .. used to be loosely based on bvme6000ints.c
11 *
12 */
13
14 #include <linux/types.h>
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/interrupt.h>
18 #include <linux/irq.h>
19
20 #include <asm/machdep.h>
21 #include <asm/ptrace.h>
22 #include <asm/traps.h>
23
24 #include <asm/q40_master.h>
25 #include <asm/q40ints.h>
26
27 #include "q40.h"
28
29 /*
30 * Q40 IRQs are defined as follows:
31 * 3,4,5,6,7,10,11,14,15 : ISA dev IRQs
32 * 16-31: reserved
33 * 32 : keyboard int
34 * 33 : frame int (50/200 Hz periodic timer)
35 * 34 : sample int (10/20 KHz periodic timer)
36 *
37 */
38
39 static void q40_irq_handler(unsigned int, struct pt_regs *fp);
40 static void q40_irq_enable(struct irq_data *data);
41 static void q40_irq_disable(struct irq_data *data);
42
43 unsigned short q40_ablecount[35];
44 unsigned short q40_state[35];
45
46 static unsigned int q40_irq_startup(struct irq_data *data)
47 {
48 unsigned int irq = data->irq;
49
50 /* test for ISA ints not implemented by HW */
51 switch (irq) {
52 case 1: case 2: case 8: case 9:
53 case 11: case 12: case 13:
54 pr_warn("%s: ISA IRQ %d not implemented by HW\n", __func__,
55 irq);
56 /* FIXME return -ENXIO; */
57 }
58 return 0;
59 }
60
61 static void q40_irq_shutdown(struct irq_data *data)
62 {
63 }
64
65 static struct irq_chip q40_irq_chip = {
66 .name = "q40",
67 .irq_startup = q40_irq_startup,
68 .irq_shutdown = q40_irq_shutdown,
69 .irq_enable = q40_irq_enable,
70 .irq_disable = q40_irq_disable,
71 };
72
73 /*
74 * void q40_init_IRQ (void)
75 *
76 * Parameters: None
77 *
78 * Returns: Nothing
79 *
80 * This function is called during kernel startup to initialize
81 * the q40 IRQ handling routines.
82 */
83
84 static int disabled;
85
86 void __init q40_init_IRQ(void)
87 {
88 m68k_setup_irq_controller(&q40_irq_chip, handle_simple_irq, 1,
89 Q40_IRQ_MAX);
90
91 /* setup handler for ISA ints */
92 m68k_setup_auto_interrupt(q40_irq_handler);
93
94 m68k_irq_startup_irq(IRQ_AUTO_2);
95 m68k_irq_startup_irq(IRQ_AUTO_4);
96
97 /* now enable some ints.. */
98 master_outb(1, EXT_ENABLE_REG); /* ISA IRQ 5-15 */
99
100 /* make sure keyboard IRQ is disabled */
101 master_outb(0, KEY_IRQ_ENABLE_REG);
102 }
103
104
105 /*
106 * this stuff doesn't really belong here..
107 */
108
109 int ql_ticks; /* 200Hz ticks since last jiffie */
110 static int sound_ticks;
111
112 #define SVOL 45
113
114 void q40_mksound(unsigned int hz, unsigned int ticks)
115 {
116 /* for now ignore hz, except that hz==0 switches off sound */
117 /* simply alternate the ampl (128-SVOL)-(128+SVOL)-..-.. at 200Hz */
118 if (hz == 0) {
119 if (sound_ticks)
120 sound_ticks = 1;
121
122 *DAC_LEFT = 128;
123 *DAC_RIGHT = 128;
124
125 return;
126 }
127 /* sound itself is done in q40_timer_int */
128 if (sound_ticks == 0)
129 sound_ticks = 1000; /* pretty long beep */
130 sound_ticks = ticks << 1;
131 }
132
133 static irqreturn_t q40_timer_int(int irq, void *dev_id)
134 {
135 ql_ticks = ql_ticks ? 0 : 1;
136 if (sound_ticks) {
137 unsigned char sval=(sound_ticks & 1) ? 128-SVOL : 128+SVOL;
138 sound_ticks--;
139 *DAC_LEFT=sval;
140 *DAC_RIGHT=sval;
141 }
142
143 if (!ql_ticks) {
144 unsigned long flags;
145
146 local_irq_save(flags);
147 legacy_timer_tick(1);
148 timer_heartbeat();
149 local_irq_restore(flags);
150 }
151 return IRQ_HANDLED;
152 }
153
154 void q40_sched_init (void)
155 {
156 int timer_irq;
157
158 timer_irq = Q40_IRQ_FRAME;
159
160 if (request_irq(timer_irq, q40_timer_int, 0, "timer", NULL))
161 panic("Couldn't register timer int");
162
163 master_outb(-1, FRAME_CLEAR_REG);
164 master_outb( 1, FRAME_RATE_REG);
165 }
166
167
168 /*
169 * tables to translate bits into IRQ numbers
170 * it is a good idea to order the entries by priority
171 *
172 */
173
174 struct IRQ_TABLE{ unsigned mask; int irq ;};
175 #if 0
176 static struct IRQ_TABLE iirqs[]={
177 {Q40_IRQ_FRAME_MASK,Q40_IRQ_FRAME},
178 {Q40_IRQ_KEYB_MASK,Q40_IRQ_KEYBOARD},
179 {0,0}};
180 #endif
181 static struct IRQ_TABLE eirqs[] = {
182 { .mask = Q40_IRQ3_MASK, .irq = 3 }, /* ser 1 */
183 { .mask = Q40_IRQ4_MASK, .irq = 4 }, /* ser 2 */
184 { .mask = Q40_IRQ14_MASK, .irq = 14 }, /* IDE 1 */
185 { .mask = Q40_IRQ15_MASK, .irq = 15 }, /* IDE 2 */
186 { .mask = Q40_IRQ6_MASK, .irq = 6 }, /* floppy, handled elsewhere */
187 { .mask = Q40_IRQ7_MASK, .irq = 7 }, /* par */
188 { .mask = Q40_IRQ5_MASK, .irq = 5 },
189 { .mask = Q40_IRQ10_MASK, .irq = 10 },
190 {0,0}
191 };
192
193 /* complain only this many times about spurious ints : */
194 static int ccleirq=60; /* ISA dev IRQs*/
195 /*static int cclirq=60;*/ /* internal */
196
197 /* FIXME: add shared ints,mask,unmask,probing.... */
198
199 #define IRQ_INPROGRESS 1
200 /*static unsigned short saved_mask;*/
201 //static int do_tint=0;
202
203 #define DEBUG_Q40INT
204 /*#define IP_USE_DISABLE *//* would be nice, but crashes ???? */
205
206 static int mext_disabled; /* ext irq disabled by master chip? */
207 static int aliased_irq; /* how many times inside handler ?*/
208
209
210 /* got interrupt, dispatch to ISA or keyboard/timer IRQs */
211 static void q40_irq_handler(unsigned int irq, struct pt_regs *fp)
212 {
213 unsigned mir, mer;
214 int i;
215
216 //repeat:
217 mir = master_inb(IIRQ_REG);
218 #ifdef CONFIG_BLK_DEV_FD
219 if ((mir & Q40_IRQ_EXT_MASK) &&
220 (master_inb(EIRQ_REG) & Q40_IRQ6_MASK)) {
221 floppy_hardint();
222 return;
223 }
224 #endif
225 switch (irq) {
226 case 4:
227 case 6:
228 do_IRQ(Q40_IRQ_SAMPLE, fp);
229 return;
230 }
231 if (mir & Q40_IRQ_FRAME_MASK) {
232 do_IRQ(Q40_IRQ_FRAME, fp);
233 master_outb(-1, FRAME_CLEAR_REG);
234 }
235 if ((mir & Q40_IRQ_SER_MASK) || (mir & Q40_IRQ_EXT_MASK)) {
236 mer = master_inb(EIRQ_REG);
237 for (i = 0; eirqs[i].mask; i++) {
238 if (mer & eirqs[i].mask) {
239 irq = eirqs[i].irq;
240 /*
241 * There is a little mess wrt which IRQ really caused this irq request. The
242 * main problem is that IIRQ_REG and EIRQ_REG reflect the state when they
243 * are read - which is long after the request came in. In theory IRQs should
244 * not just go away but they occasionally do
245 */
246 if (irq > 4 && irq <= 15 && mext_disabled) {
247 /*aliased_irq++;*/
248 goto iirq;
249 }
250 if (q40_state[irq] & IRQ_INPROGRESS) {
251 /* some handlers do local_irq_enable() for irq latency reasons, */
252 /* however reentering an active irq handler is not permitted */
253 #ifdef IP_USE_DISABLE
254 /* in theory this is the better way to do it because it still */
255 /* lets through eg the serial irqs, unfortunately it crashes */
256 disable_irq(irq);
257 disabled = 1;
258 #else
259 /*pr_warn("IRQ_INPROGRESS detected for irq %d, disabling - %s disabled\n",
260 irq, disabled ? "already" : "not yet"); */
261 fp->sr = (((fp->sr) & (~0x700))+0x200);
262 disabled = 1;
263 #endif
264 goto iirq;
265 }
266 q40_state[irq] |= IRQ_INPROGRESS;
267 do_IRQ(irq, fp);
268 q40_state[irq] &= ~IRQ_INPROGRESS;
269
270 /* naively enable everything, if that fails than */
271 /* this function will be reentered immediately thus */
272 /* getting another chance to disable the IRQ */
273
274 if (disabled) {
275 #ifdef IP_USE_DISABLE
276 if (irq > 4) {
277 disabled = 0;
278 enable_irq(irq);
279 }
280 #else
281 disabled = 0;
282 /*pr_info("reenabling irq %d\n", irq); */
283 #endif
284 }
285 // used to do 'goto repeat;' here, this delayed bh processing too long
286 return;
287 }
288 }
289 if (mer && ccleirq > 0 && !aliased_irq) {
290 pr_warn("ISA interrupt from unknown source? EIRQ_REG = %x\n",
291 mer);
292 ccleirq--;
293 }
294 }
295 iirq:
296 mir = master_inb(IIRQ_REG);
297 /* should test whether keyboard irq is really enabled, doing it in defhand */
298 if (mir & Q40_IRQ_KEYB_MASK)
299 do_IRQ(Q40_IRQ_KEYBOARD, fp);
300
301 return;
302 }
303
304 void q40_irq_enable(struct irq_data *data)
305 {
306 unsigned int irq = data->irq;
307
308 if (irq >= 5 && irq <= 15) {
309 mext_disabled--;
310 if (mext_disabled > 0)
311 pr_warn("q40_irq_enable : nested disable/enable\n");
312 if (mext_disabled == 0)
313 master_outb(1, EXT_ENABLE_REG);
314 }
315 }
316
317
318 void q40_irq_disable(struct irq_data *data)
319 {
320 unsigned int irq = data->irq;
321
322 /* disable ISA iqs : only do something if the driver has been
323 * verified to be Q40 "compatible" - right now IDE, NE2K
324 * Any driver should not attempt to sleep across disable_irq !!
325 */
326
327 if (irq >= 5 && irq <= 15) {
328 master_outb(0, EXT_ENABLE_REG);
329 mext_disabled++;
330 if (mext_disabled > 1)
331 pr_info("disable_irq nesting count %d\n",
332 mext_disabled);
333 }
334 }
335
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