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/ptrace.h>
21 #include <asm/traps.h>
22
23 #include <asm/q40_master.h>
24 #include <asm/q40ints.h>
25
26 /*
27 * Q40 IRQs are defined as follows:
28 * 3,4,5,6,7,10,11,14,15 : ISA dev IRQs
29 * 16-31: reserved
30 * 32 : keyboard int
31 * 33 : frame int (50/200 Hz periodic timer)
32 * 34 : sample int (10/20 KHz periodic timer)
33 *
34 */
35
36 static void q40_irq_handler(unsigned int, struct pt_regs *fp);
37 static void q40_irq_enable(struct irq_data *data);
38 static void q40_irq_disable(struct irq_data *data);
39
40 unsigned short q40_ablecount[35];
41 unsigned short q40_state[35];
42
q40_irq_startup(struct irq_data * data)43 static unsigned int q40_irq_startup(struct irq_data *data)
44 {
45 unsigned int irq = data->irq;
46
47 /* test for ISA ints not implemented by HW */
48 switch (irq) {
49 case 1: case 2: case 8: case 9:
50 case 11: case 12: case 13:
51 printk("%s: ISA IRQ %d not implemented by HW\n", __func__, irq);
52 /* FIXME return -ENXIO; */
53 }
54 return 0;
55 }
56
q40_irq_shutdown(struct irq_data * data)57 static void q40_irq_shutdown(struct irq_data *data)
58 {
59 }
60
61 static struct irq_chip q40_irq_chip = {
62 .name = "q40",
63 .irq_startup = q40_irq_startup,
64 .irq_shutdown = q40_irq_shutdown,
65 .irq_enable = q40_irq_enable,
66 .irq_disable = q40_irq_disable,
67 };
68
69 /*
70 * void q40_init_IRQ (void)
71 *
72 * Parameters: None
73 *
74 * Returns: Nothing
75 *
76 * This function is called during kernel startup to initialize
77 * the q40 IRQ handling routines.
78 */
79
80 static int disabled;
81
q40_init_IRQ(void)82 void __init q40_init_IRQ(void)
83 {
84 m68k_setup_irq_controller(&q40_irq_chip, handle_simple_irq, 1,
85 Q40_IRQ_MAX);
86
87 /* setup handler for ISA ints */
88 m68k_setup_auto_interrupt(q40_irq_handler);
89
90 m68k_irq_startup_irq(IRQ_AUTO_2);
91 m68k_irq_startup_irq(IRQ_AUTO_4);
92
93 /* now enable some ints.. */
94 master_outb(1, EXT_ENABLE_REG); /* ISA IRQ 5-15 */
95
96 /* make sure keyboard IRQ is disabled */
97 master_outb(0, KEY_IRQ_ENABLE_REG);
98 }
99
100
101 /*
102 * this stuff doesn't really belong here..
103 */
104
105 int ql_ticks; /* 200Hz ticks since last jiffie */
106 static int sound_ticks;
107
108 #define SVOL 45
109
q40_mksound(unsigned int hz,unsigned int ticks)110 void q40_mksound(unsigned int hz, unsigned int ticks)
111 {
112 /* for now ignore hz, except that hz==0 switches off sound */
113 /* simply alternate the ampl (128-SVOL)-(128+SVOL)-..-.. at 200Hz */
114 if (hz == 0) {
115 if (sound_ticks)
116 sound_ticks = 1;
117
118 *DAC_LEFT = 128;
119 *DAC_RIGHT = 128;
120
121 return;
122 }
123 /* sound itself is done in q40_timer_int */
124 if (sound_ticks == 0)
125 sound_ticks = 1000; /* pretty long beep */
126 sound_ticks = ticks << 1;
127 }
128
129 static irq_handler_t q40_timer_routine;
130
q40_timer_int(int irq,void * dev)131 static irqreturn_t q40_timer_int (int irq, void * dev)
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 q40_timer_routine(irq, dev);
143 return IRQ_HANDLED;
144 }
145
q40_sched_init(irq_handler_t timer_routine)146 void q40_sched_init (irq_handler_t timer_routine)
147 {
148 int timer_irq;
149
150 q40_timer_routine = timer_routine;
151 timer_irq = Q40_IRQ_FRAME;
152
153 if (request_irq(timer_irq, q40_timer_int, 0,
154 "timer", q40_timer_int))
155 panic("Couldn't register timer int");
156
157 master_outb(-1, FRAME_CLEAR_REG);
158 master_outb( 1, FRAME_RATE_REG);
159 }
160
161
162 /*
163 * tables to translate bits into IRQ numbers
164 * it is a good idea to order the entries by priority
165 *
166 */
167
168 struct IRQ_TABLE{ unsigned mask; int irq ;};
169 #if 0
170 static struct IRQ_TABLE iirqs[]={
171 {Q40_IRQ_FRAME_MASK,Q40_IRQ_FRAME},
172 {Q40_IRQ_KEYB_MASK,Q40_IRQ_KEYBOARD},
173 {0,0}};
174 #endif
175 static struct IRQ_TABLE eirqs[] = {
176 { .mask = Q40_IRQ3_MASK, .irq = 3 }, /* ser 1 */
177 { .mask = Q40_IRQ4_MASK, .irq = 4 }, /* ser 2 */
178 { .mask = Q40_IRQ14_MASK, .irq = 14 }, /* IDE 1 */
179 { .mask = Q40_IRQ15_MASK, .irq = 15 }, /* IDE 2 */
180 { .mask = Q40_IRQ6_MASK, .irq = 6 }, /* floppy, handled elsewhere */
181 { .mask = Q40_IRQ7_MASK, .irq = 7 }, /* par */
182 { .mask = Q40_IRQ5_MASK, .irq = 5 },
183 { .mask = Q40_IRQ10_MASK, .irq = 10 },
184 {0,0}
185 };
186
187 /* complain only this many times about spurious ints : */
188 static int ccleirq=60; /* ISA dev IRQs*/
189 /*static int cclirq=60;*/ /* internal */
190
191 /* FIXME: add shared ints,mask,unmask,probing.... */
192
193 #define IRQ_INPROGRESS 1
194 /*static unsigned short saved_mask;*/
195 //static int do_tint=0;
196
197 #define DEBUG_Q40INT
198 /*#define IP_USE_DISABLE *//* would be nice, but crashes ???? */
199
200 static int mext_disabled=0; /* ext irq disabled by master chip? */
201 static int aliased_irq=0; /* how many times inside handler ?*/
202
203
204 /* got interrupt, dispatch to ISA or keyboard/timer IRQs */
q40_irq_handler(unsigned int irq,struct pt_regs * fp)205 static void q40_irq_handler(unsigned int irq, struct pt_regs *fp)
206 {
207 unsigned mir, mer;
208 int i;
209
210 //repeat:
211 mir = master_inb(IIRQ_REG);
212 #ifdef CONFIG_BLK_DEV_FD
213 if ((mir & Q40_IRQ_EXT_MASK) &&
214 (master_inb(EIRQ_REG) & Q40_IRQ6_MASK)) {
215 floppy_hardint();
216 return;
217 }
218 #endif
219 switch (irq) {
220 case 4:
221 case 6:
222 do_IRQ(Q40_IRQ_SAMPLE, fp);
223 return;
224 }
225 if (mir & Q40_IRQ_FRAME_MASK) {
226 do_IRQ(Q40_IRQ_FRAME, fp);
227 master_outb(-1, FRAME_CLEAR_REG);
228 }
229 if ((mir & Q40_IRQ_SER_MASK) || (mir & Q40_IRQ_EXT_MASK)) {
230 mer = master_inb(EIRQ_REG);
231 for (i = 0; eirqs[i].mask; i++) {
232 if (mer & eirqs[i].mask) {
233 irq = eirqs[i].irq;
234 /*
235 * There is a little mess wrt which IRQ really caused this irq request. The
236 * main problem is that IIRQ_REG and EIRQ_REG reflect the state when they
237 * are read - which is long after the request came in. In theory IRQs should
238 * not just go away but they occasionally do
239 */
240 if (irq > 4 && irq <= 15 && mext_disabled) {
241 /*aliased_irq++;*/
242 goto iirq;
243 }
244 if (q40_state[irq] & IRQ_INPROGRESS) {
245 /* some handlers do local_irq_enable() for irq latency reasons, */
246 /* however reentering an active irq handler is not permitted */
247 #ifdef IP_USE_DISABLE
248 /* in theory this is the better way to do it because it still */
249 /* lets through eg the serial irqs, unfortunately it crashes */
250 disable_irq(irq);
251 disabled = 1;
252 #else
253 /*printk("IRQ_INPROGRESS detected for irq %d, disabling - %s disabled\n",
254 irq, disabled ? "already" : "not yet"); */
255 fp->sr = (((fp->sr) & (~0x700))+0x200);
256 disabled = 1;
257 #endif
258 goto iirq;
259 }
260 q40_state[irq] |= IRQ_INPROGRESS;
261 do_IRQ(irq, fp);
262 q40_state[irq] &= ~IRQ_INPROGRESS;
263
264 /* naively enable everything, if that fails than */
265 /* this function will be reentered immediately thus */
266 /* getting another chance to disable the IRQ */
267
268 if (disabled) {
269 #ifdef IP_USE_DISABLE
270 if (irq > 4) {
271 disabled = 0;
272 enable_irq(irq);
273 }
274 #else
275 disabled = 0;
276 /*printk("reenabling irq %d\n", irq); */
277 #endif
278 }
279 // used to do 'goto repeat;' here, this delayed bh processing too long
280 return;
281 }
282 }
283 if (mer && ccleirq > 0 && !aliased_irq) {
284 printk("ISA interrupt from unknown source? EIRQ_REG = %x\n",mer);
285 ccleirq--;
286 }
287 }
288 iirq:
289 mir = master_inb(IIRQ_REG);
290 /* should test whether keyboard irq is really enabled, doing it in defhand */
291 if (mir & Q40_IRQ_KEYB_MASK)
292 do_IRQ(Q40_IRQ_KEYBOARD, fp);
293
294 return;
295 }
296
q40_irq_enable(struct irq_data * data)297 void q40_irq_enable(struct irq_data *data)
298 {
299 unsigned int irq = data->irq;
300
301 if (irq >= 5 && irq <= 15) {
302 mext_disabled--;
303 if (mext_disabled > 0)
304 printk("q40_irq_enable : nested disable/enable\n");
305 if (mext_disabled == 0)
306 master_outb(1, EXT_ENABLE_REG);
307 }
308 }
309
310
q40_irq_disable(struct irq_data * data)311 void q40_irq_disable(struct irq_data *data)
312 {
313 unsigned int irq = data->irq;
314
315 /* disable ISA iqs : only do something if the driver has been
316 * verified to be Q40 "compatible" - right now IDE, NE2K
317 * Any driver should not attempt to sleep across disable_irq !!
318 */
319
320 if (irq >= 5 && irq <= 15) {
321 master_outb(0, EXT_ENABLE_REG);
322 mext_disabled++;
323 if (mext_disabled > 1)
324 printk("disable_irq nesting count %d\n",mext_disabled);
325 }
326 }
327