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