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
19 #include <asm/ptrace.h>
20 #include <asm/system.h>
21 #include <asm/irq.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_enable_irq(unsigned int);
39 static void q40_disable_irq(unsigned int);
40
41 unsigned short q40_ablecount[35];
42 unsigned short q40_state[35];
43
q40_irq_startup(unsigned int irq)44 static int q40_irq_startup(unsigned int irq)
45 {
46 /* test for ISA ints not implemented by HW */
47 switch (irq) {
48 case 1: case 2: case 8: case 9:
49 case 11: case 12: case 13:
50 printk("%s: ISA IRQ %d not implemented by HW\n", __func__, irq);
51 return -ENXIO;
52 }
53 return 0;
54 }
55
q40_irq_shutdown(unsigned int irq)56 static void q40_irq_shutdown(unsigned int irq)
57 {
58 }
59
60 static struct irq_controller q40_irq_controller = {
61 .name = "q40",
62 .lock = __SPIN_LOCK_UNLOCKED(q40_irq_controller.lock),
63 .startup = q40_irq_startup,
64 .shutdown = q40_irq_shutdown,
65 .enable = q40_enable_irq,
66 .disable = q40_disable_irq,
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_controller, 1, Q40_IRQ_MAX);
85
86 /* setup handler for ISA ints */
87 m68k_setup_auto_interrupt(q40_irq_handler);
88
89 m68k_irq_startup(IRQ_AUTO_2);
90 m68k_irq_startup(IRQ_AUTO_4);
91
92 /* now enable some ints.. */
93 master_outb(1, EXT_ENABLE_REG); /* ISA IRQ 5-15 */
94
95 /* make sure keyboard IRQ is disabled */
96 master_outb(0, KEY_IRQ_ENABLE_REG);
97 }
98
99
100 /*
101 * this stuff doesn't really belong here..
102 */
103
104 int ql_ticks; /* 200Hz ticks since last jiffie */
105 static int sound_ticks;
106
107 #define SVOL 45
108
q40_mksound(unsigned int hz,unsigned int ticks)109 void q40_mksound(unsigned int hz, unsigned int ticks)
110 {
111 /* for now ignore hz, except that hz==0 switches off sound */
112 /* simply alternate the ampl (128-SVOL)-(128+SVOL)-..-.. at 200Hz */
113 if (hz == 0) {
114 if (sound_ticks)
115 sound_ticks = 1;
116
117 *DAC_LEFT = 128;
118 *DAC_RIGHT = 128;
119
120 return;
121 }
122 /* sound itself is done in q40_timer_int */
123 if (sound_ticks == 0)
124 sound_ticks = 1000; /* pretty long beep */
125 sound_ticks = ticks << 1;
126 }
127
128 static irq_handler_t q40_timer_routine;
129
q40_timer_int(int irq,void * dev)130 static irqreturn_t q40_timer_int (int irq, void * dev)
131 {
132 ql_ticks = ql_ticks ? 0 : 1;
133 if (sound_ticks) {
134 unsigned char sval=(sound_ticks & 1) ? 128-SVOL : 128+SVOL;
135 sound_ticks--;
136 *DAC_LEFT=sval;
137 *DAC_RIGHT=sval;
138 }
139
140 if (!ql_ticks)
141 q40_timer_routine(irq, dev);
142 return IRQ_HANDLED;
143 }
144
q40_sched_init(irq_handler_t timer_routine)145 void q40_sched_init (irq_handler_t timer_routine)
146 {
147 int timer_irq;
148
149 q40_timer_routine = timer_routine;
150 timer_irq = Q40_IRQ_FRAME;
151
152 if (request_irq(timer_irq, q40_timer_int, 0,
153 "timer", q40_timer_int))
154 panic("Couldn't register timer int");
155
156 master_outb(-1, FRAME_CLEAR_REG);
157 master_outb( 1, FRAME_RATE_REG);
158 }
159
160
161 /*
162 * tables to translate bits into IRQ numbers
163 * it is a good idea to order the entries by priority
164 *
165 */
166
167 struct IRQ_TABLE{ unsigned mask; int irq ;};
168 #if 0
169 static struct IRQ_TABLE iirqs[]={
170 {Q40_IRQ_FRAME_MASK,Q40_IRQ_FRAME},
171 {Q40_IRQ_KEYB_MASK,Q40_IRQ_KEYBOARD},
172 {0,0}};
173 #endif
174 static struct IRQ_TABLE eirqs[] = {
175 { .mask = Q40_IRQ3_MASK, .irq = 3 }, /* ser 1 */
176 { .mask = Q40_IRQ4_MASK, .irq = 4 }, /* ser 2 */
177 { .mask = Q40_IRQ14_MASK, .irq = 14 }, /* IDE 1 */
178 { .mask = Q40_IRQ15_MASK, .irq = 15 }, /* IDE 2 */
179 { .mask = Q40_IRQ6_MASK, .irq = 6 }, /* floppy, handled elsewhere */
180 { .mask = Q40_IRQ7_MASK, .irq = 7 }, /* par */
181 { .mask = Q40_IRQ5_MASK, .irq = 5 },
182 { .mask = Q40_IRQ10_MASK, .irq = 10 },
183 {0,0}
184 };
185
186 /* complain only this many times about spurious ints : */
187 static int ccleirq=60; /* ISA dev IRQs*/
188 /*static int cclirq=60;*/ /* internal */
189
190 /* FIXME: add shared ints,mask,unmask,probing.... */
191
192 #define IRQ_INPROGRESS 1
193 /*static unsigned short saved_mask;*/
194 //static int do_tint=0;
195
196 #define DEBUG_Q40INT
197 /*#define IP_USE_DISABLE *//* would be nice, but crashes ???? */
198
199 static int mext_disabled=0; /* ext irq disabled by master chip? */
200 static int aliased_irq=0; /* how many times inside handler ?*/
201
202
203 /* got interrupt, dispatch to ISA or keyboard/timer IRQs */
q40_irq_handler(unsigned int irq,struct pt_regs * fp)204 static void q40_irq_handler(unsigned int irq, struct pt_regs *fp)
205 {
206 unsigned mir, mer;
207 int i;
208
209 //repeat:
210 mir = master_inb(IIRQ_REG);
211 #ifdef CONFIG_BLK_DEV_FD
212 if ((mir & Q40_IRQ_EXT_MASK) &&
213 (master_inb(EIRQ_REG) & Q40_IRQ6_MASK)) {
214 floppy_hardint();
215 return;
216 }
217 #endif
218 switch (irq) {
219 case 4:
220 case 6:
221 __m68k_handle_int(Q40_IRQ_SAMPLE, fp);
222 return;
223 }
224 if (mir & Q40_IRQ_FRAME_MASK) {
225 __m68k_handle_int(Q40_IRQ_FRAME, fp);
226 master_outb(-1, FRAME_CLEAR_REG);
227 }
228 if ((mir & Q40_IRQ_SER_MASK) || (mir & Q40_IRQ_EXT_MASK)) {
229 mer = master_inb(EIRQ_REG);
230 for (i = 0; eirqs[i].mask; i++) {
231 if (mer & eirqs[i].mask) {
232 irq = eirqs[i].irq;
233 /*
234 * There is a little mess wrt which IRQ really caused this irq request. The
235 * main problem is that IIRQ_REG and EIRQ_REG reflect the state when they
236 * are read - which is long after the request came in. In theory IRQs should
237 * not just go away but they occasionally do
238 */
239 if (irq > 4 && irq <= 15 && mext_disabled) {
240 /*aliased_irq++;*/
241 goto iirq;
242 }
243 if (q40_state[irq] & IRQ_INPROGRESS) {
244 /* some handlers do local_irq_enable() for irq latency reasons, */
245 /* however reentering an active irq handler is not permitted */
246 #ifdef IP_USE_DISABLE
247 /* in theory this is the better way to do it because it still */
248 /* lets through eg the serial irqs, unfortunately it crashes */
249 disable_irq(irq);
250 disabled = 1;
251 #else
252 /*printk("IRQ_INPROGRESS detected for irq %d, disabling - %s disabled\n",
253 irq, disabled ? "already" : "not yet"); */
254 fp->sr = (((fp->sr) & (~0x700))+0x200);
255 disabled = 1;
256 #endif
257 goto iirq;
258 }
259 q40_state[irq] |= IRQ_INPROGRESS;
260 __m68k_handle_int(irq, fp);
261 q40_state[irq] &= ~IRQ_INPROGRESS;
262
263 /* naively enable everything, if that fails than */
264 /* this function will be reentered immediately thus */
265 /* getting another chance to disable the IRQ */
266
267 if (disabled) {
268 #ifdef IP_USE_DISABLE
269 if (irq > 4) {
270 disabled = 0;
271 enable_irq(irq);
272 }
273 #else
274 disabled = 0;
275 /*printk("reenabling irq %d\n", irq); */
276 #endif
277 }
278 // used to do 'goto repeat;' here, this delayed bh processing too long
279 return;
280 }
281 }
282 if (mer && ccleirq > 0 && !aliased_irq) {
283 printk("ISA interrupt from unknown source? EIRQ_REG = %x\n",mer);
284 ccleirq--;
285 }
286 }
287 iirq:
288 mir = master_inb(IIRQ_REG);
289 /* should test whether keyboard irq is really enabled, doing it in defhand */
290 if (mir & Q40_IRQ_KEYB_MASK)
291 __m68k_handle_int(Q40_IRQ_KEYBOARD, fp);
292
293 return;
294 }
295
q40_enable_irq(unsigned int irq)296 void q40_enable_irq(unsigned int irq)
297 {
298 if (irq >= 5 && irq <= 15) {
299 mext_disabled--;
300 if (mext_disabled > 0)
301 printk("q40_enable_irq : nested disable/enable\n");
302 if (mext_disabled == 0)
303 master_outb(1, EXT_ENABLE_REG);
304 }
305 }
306
307
q40_disable_irq(unsigned int irq)308 void q40_disable_irq(unsigned int irq)
309 {
310 /* disable ISA iqs : only do something if the driver has been
311 * verified to be Q40 "compatible" - right now IDE, NE2K
312 * Any driver should not attempt to sleep across disable_irq !!
313 */
314
315 if (irq >= 5 && irq <= 15) {
316 master_outb(0, EXT_ENABLE_REG);
317 mext_disabled++;
318 if (mext_disabled > 1)
319 printk("disable_irq nesting count %d\n",mext_disabled);
320 }
321 }
322
q40_probe_irq_on(void)323 unsigned long q40_probe_irq_on(void)
324 {
325 printk("irq probing not working - reconfigure the driver to avoid this\n");
326 return -1;
327 }
q40_probe_irq_off(unsigned long irqs)328 int q40_probe_irq_off(unsigned long irqs)
329 {
330 return -1;
331 }
332