xref: /openbmc/linux/arch/m68k/amiga/amiints.c (revision b4290a23cfa9040e2f0de5ab57d6ea65abaf053b)
1 /*
2  * linux/arch/m68k/amiga/amiints.c -- Amiga Linux interrupt handling code
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file COPYING in the main directory of this archive
6  * for more details.
7  *
8  * 11/07/96: rewritten interrupt handling, irq lists are exists now only for
9  *           this sources where it makes sense (VERTB/PORTS/EXTER) and you must
10  *           be careful that dev_id for this sources is unique since this the
11  *           only possibility to distinguish between different handlers for
12  *           free_irq. irq lists also have different irq flags:
13  *           - IRQ_FLG_FAST: handler is inserted at top of list (after other
14  *                           fast handlers)
15  *           - IRQ_FLG_SLOW: handler is inserted at bottom of list and before
16  *                           they're executed irq level is set to the previous
17  *                           one, but handlers don't need to be reentrant, if
18  *                           reentrance occurred, slow handlers will be just
19  *                           called again.
20  *           The whole interrupt handling for CIAs is moved to cia.c
21  *           /Roman Zippel
22  *
23  * 07/08/99: rewamp of the interrupt handling - we now have two types of
24  *           interrupts, normal and fast handlers, fast handlers being
25  *           marked with SA_INTERRUPT and runs with all other interrupts
26  *           disabled. Normal interrupts disable their own source but
27  *           run with all other interrupt sources enabled.
28  *           PORTS and EXTER interrupts are always shared even if the
29  *           drivers do not explicitly mark this when calling
30  *           request_irq which they really should do.
31  *           This is similar to the way interrupts are handled on all
32  *           other architectures and makes a ton of sense besides
33  *           having the advantage of making it easier to share
34  *           drivers.
35  *           /Jes
36  */
37 
38 #include <linux/types.h>
39 #include <linux/kernel.h>
40 #include <linux/sched.h>
41 #include <linux/kernel_stat.h>
42 #include <linux/init.h>
43 #include <linux/errno.h>
44 #include <linux/seq_file.h>
45 
46 #include <asm/system.h>
47 #include <asm/irq.h>
48 #include <asm/traps.h>
49 #include <asm/amigahw.h>
50 #include <asm/amigaints.h>
51 #include <asm/amipcmcia.h>
52 
53 extern int cia_request_irq(struct ciabase *base,int irq,
54                            irqreturn_t (*handler)(int, void *, struct pt_regs *),
55                            unsigned long flags, const char *devname, void *dev_id);
56 extern void cia_free_irq(struct ciabase *base, unsigned int irq, void *dev_id);
57 extern void cia_init_IRQ(struct ciabase *base);
58 extern int cia_get_irq_list(struct ciabase *base, struct seq_file *p);
59 
60 /* irq node variables for amiga interrupt sources */
61 static irq_node_t *ami_irq_list[AMI_STD_IRQS];
62 
63 static unsigned short amiga_intena_vals[AMI_STD_IRQS] = {
64 	[IRQ_AMIGA_VERTB]	= IF_VERTB,
65 	[IRQ_AMIGA_COPPER]	= IF_COPER,
66 	[IRQ_AMIGA_AUD0]	= IF_AUD0,
67 	[IRQ_AMIGA_AUD1]	= IF_AUD1,
68 	[IRQ_AMIGA_AUD2]	= IF_AUD2,
69 	[IRQ_AMIGA_AUD3]	= IF_AUD3,
70 	[IRQ_AMIGA_BLIT]	= IF_BLIT,
71 	[IRQ_AMIGA_DSKSYN]	= IF_DSKSYN,
72 	[IRQ_AMIGA_DSKBLK]	= IF_DSKBLK,
73 	[IRQ_AMIGA_RBF]		= IF_RBF,
74 	[IRQ_AMIGA_TBE]		= IF_TBE,
75 	[IRQ_AMIGA_SOFT]	= IF_SOFT,
76 	[IRQ_AMIGA_PORTS]	= IF_PORTS,
77 	[IRQ_AMIGA_EXTER]	= IF_EXTER
78 };
79 static const unsigned char ami_servers[AMI_STD_IRQS] = {
80 	[IRQ_AMIGA_VERTB]	= 1,
81 	[IRQ_AMIGA_PORTS]	= 1,
82 	[IRQ_AMIGA_EXTER]	= 1
83 };
84 
85 static short ami_ablecount[AMI_IRQS];
86 
87 static irqreturn_t ami_badint(int irq, void *dev_id, struct pt_regs *fp)
88 {
89 	num_spurious += 1;
90 	return IRQ_NONE;
91 }
92 
93 /*
94  * void amiga_init_IRQ(void)
95  *
96  * Parameters:	None
97  *
98  * Returns:	Nothing
99  *
100  * This function should be called during kernel startup to initialize
101  * the amiga IRQ handling routines.
102  */
103 
104 void __init amiga_init_IRQ(void)
105 {
106 	int i;
107 
108 	/* initialize handlers */
109 	for (i = 0; i < AMI_STD_IRQS; i++) {
110 		if (ami_servers[i]) {
111 			ami_irq_list[i] = NULL;
112 		} else {
113 			ami_irq_list[i] = new_irq_node();
114 			ami_irq_list[i]->handler = ami_badint;
115 			ami_irq_list[i]->flags   = 0;
116 			ami_irq_list[i]->dev_id  = NULL;
117 			ami_irq_list[i]->devname = NULL;
118 			ami_irq_list[i]->next    = NULL;
119 		}
120 	}
121 	for (i = 0; i < AMI_IRQS; i++)
122 		ami_ablecount[i] = 0;
123 
124 	/* turn off PCMCIA interrupts */
125 	if (AMIGAHW_PRESENT(PCMCIA))
126 		gayle.inten = GAYLE_IRQ_IDE;
127 
128 	/* turn off all interrupts and enable the master interrupt bit */
129 	amiga_custom.intena = 0x7fff;
130 	amiga_custom.intreq = 0x7fff;
131 	amiga_custom.intena = IF_SETCLR | IF_INTEN;
132 
133 	cia_init_IRQ(&ciaa_base);
134 	cia_init_IRQ(&ciab_base);
135 }
136 
137 static inline int amiga_insert_irq(irq_node_t **list, irq_node_t *node)
138 {
139 	unsigned long flags;
140 	irq_node_t *cur;
141 
142 	if (!node->dev_id)
143 		printk("%s: Warning: dev_id of %s is zero\n",
144 		       __FUNCTION__, node->devname);
145 
146 	local_irq_save(flags);
147 
148 	cur = *list;
149 
150 	if (node->flags & SA_INTERRUPT) {
151 		if (node->flags & SA_SHIRQ)
152 			return -EBUSY;
153 		/*
154 		 * There should never be more than one
155 		 */
156 		while (cur && cur->flags & SA_INTERRUPT) {
157 			list = &cur->next;
158 			cur = cur->next;
159 		}
160 	} else {
161 		while (cur) {
162 			list = &cur->next;
163 			cur = cur->next;
164 		}
165 	}
166 
167 	node->next = cur;
168 	*list = node;
169 
170 	local_irq_restore(flags);
171 	return 0;
172 }
173 
174 static inline void amiga_delete_irq(irq_node_t **list, void *dev_id)
175 {
176 	unsigned long flags;
177 	irq_node_t *node;
178 
179 	local_irq_save(flags);
180 
181 	for (node = *list; node; list = &node->next, node = *list) {
182 		if (node->dev_id == dev_id) {
183 			*list = node->next;
184 			/* Mark it as free. */
185 			node->handler = NULL;
186 			local_irq_restore(flags);
187 			return;
188 		}
189 	}
190 	local_irq_restore(flags);
191 	printk ("%s: tried to remove invalid irq\n", __FUNCTION__);
192 }
193 
194 /*
195  * amiga_request_irq : add an interrupt service routine for a particular
196  *                     machine specific interrupt source.
197  *                     If the addition was successful, it returns 0.
198  */
199 
200 int amiga_request_irq(unsigned int irq,
201 		      irqreturn_t (*handler)(int, void *, struct pt_regs *),
202                       unsigned long flags, const char *devname, void *dev_id)
203 {
204 	irq_node_t *node;
205 	int error = 0;
206 
207 	if (irq >= AMI_IRQS) {
208 		printk ("%s: Unknown IRQ %d from %s\n", __FUNCTION__,
209 			irq, devname);
210 		return -ENXIO;
211 	}
212 
213 	if (irq >= IRQ_AMIGA_AUTO)
214 		return cpu_request_irq(irq - IRQ_AMIGA_AUTO, handler,
215 		                       flags, devname, dev_id);
216 
217 	if (irq >= IRQ_AMIGA_CIAB)
218 		return cia_request_irq(&ciab_base, irq - IRQ_AMIGA_CIAB,
219 		                       handler, flags, devname, dev_id);
220 
221 	if (irq >= IRQ_AMIGA_CIAA)
222 		return cia_request_irq(&ciaa_base, irq - IRQ_AMIGA_CIAA,
223 		                       handler, flags, devname, dev_id);
224 
225 	/*
226 	 * IRQ_AMIGA_PORTS & IRQ_AMIGA_EXTER defaults to shared,
227 	 * we could add a check here for the SA_SHIRQ flag but all drivers
228 	 * should be aware of sharing anyway.
229 	 */
230 	if (ami_servers[irq]) {
231 		if (!(node = new_irq_node()))
232 			return -ENOMEM;
233 		node->handler = handler;
234 		node->flags   = flags;
235 		node->dev_id  = dev_id;
236 		node->devname = devname;
237 		node->next    = NULL;
238 		error = amiga_insert_irq(&ami_irq_list[irq], node);
239 	} else {
240 		ami_irq_list[irq]->handler = handler;
241 		ami_irq_list[irq]->flags   = flags;
242 		ami_irq_list[irq]->dev_id  = dev_id;
243 		ami_irq_list[irq]->devname = devname;
244 	}
245 
246 	/* enable the interrupt */
247 	if (irq < IRQ_AMIGA_PORTS && !ami_ablecount[irq])
248 		amiga_custom.intena = IF_SETCLR | amiga_intena_vals[irq];
249 
250 	return error;
251 }
252 
253 void amiga_free_irq(unsigned int irq, void *dev_id)
254 {
255 	if (irq >= AMI_IRQS) {
256 		printk ("%s: Unknown IRQ %d\n", __FUNCTION__, irq);
257 		return;
258 	}
259 
260 	if (irq >= IRQ_AMIGA_AUTO)
261 		cpu_free_irq(irq - IRQ_AMIGA_AUTO, dev_id);
262 
263 	if (irq >= IRQ_AMIGA_CIAB) {
264 		cia_free_irq(&ciab_base, irq - IRQ_AMIGA_CIAB, dev_id);
265 		return;
266 	}
267 
268 	if (irq >= IRQ_AMIGA_CIAA) {
269 		cia_free_irq(&ciaa_base, irq - IRQ_AMIGA_CIAA, dev_id);
270 		return;
271 	}
272 
273 	if (ami_servers[irq]) {
274 		amiga_delete_irq(&ami_irq_list[irq], dev_id);
275 		/* if server list empty, disable the interrupt */
276 		if (!ami_irq_list[irq] && irq < IRQ_AMIGA_PORTS)
277 			amiga_custom.intena = amiga_intena_vals[irq];
278 	} else {
279 		if (ami_irq_list[irq]->dev_id != dev_id)
280 			printk("%s: removing probably wrong IRQ %d from %s\n",
281 			       __FUNCTION__, irq, ami_irq_list[irq]->devname);
282 		ami_irq_list[irq]->handler = ami_badint;
283 		ami_irq_list[irq]->flags   = 0;
284 		ami_irq_list[irq]->dev_id  = NULL;
285 		ami_irq_list[irq]->devname = NULL;
286 		amiga_custom.intena = amiga_intena_vals[irq];
287 	}
288 }
289 
290 /*
291  * Enable/disable a particular machine specific interrupt source.
292  * Note that this may affect other interrupts in case of a shared interrupt.
293  * This function should only be called for a _very_ short time to change some
294  * internal data, that may not be changed by the interrupt at the same time.
295  * ami_(enable|disable)_irq calls may also be nested.
296  */
297 
298 void amiga_enable_irq(unsigned int irq)
299 {
300 	if (irq >= AMI_IRQS) {
301 		printk("%s: Unknown IRQ %d\n", __FUNCTION__, irq);
302 		return;
303 	}
304 
305 	if (--ami_ablecount[irq])
306 		return;
307 
308 	/* No action for auto-vector interrupts */
309 	if (irq >= IRQ_AMIGA_AUTO){
310 		printk("%s: Trying to enable auto-vector IRQ %i\n",
311 		       __FUNCTION__, irq - IRQ_AMIGA_AUTO);
312 		return;
313 	}
314 
315 	if (irq >= IRQ_AMIGA_CIAB) {
316 		cia_set_irq(&ciab_base, (1 << (irq - IRQ_AMIGA_CIAB)));
317 		cia_able_irq(&ciab_base, CIA_ICR_SETCLR |
318 		             (1 << (irq - IRQ_AMIGA_CIAB)));
319 		return;
320 	}
321 
322 	if (irq >= IRQ_AMIGA_CIAA) {
323 		cia_set_irq(&ciaa_base, (1 << (irq - IRQ_AMIGA_CIAA)));
324 		cia_able_irq(&ciaa_base, CIA_ICR_SETCLR |
325 		             (1 << (irq - IRQ_AMIGA_CIAA)));
326 		return;
327 	}
328 
329 	/* enable the interrupt */
330 	amiga_custom.intena = IF_SETCLR | amiga_intena_vals[irq];
331 }
332 
333 void amiga_disable_irq(unsigned int irq)
334 {
335 	if (irq >= AMI_IRQS) {
336 		printk("%s: Unknown IRQ %d\n", __FUNCTION__, irq);
337 		return;
338 	}
339 
340 	if (ami_ablecount[irq]++)
341 		return;
342 
343 	/* No action for auto-vector interrupts */
344 	if (irq >= IRQ_AMIGA_AUTO) {
345 		printk("%s: Trying to disable auto-vector IRQ %i\n",
346 		       __FUNCTION__, irq - IRQ_AMIGA_AUTO);
347 		return;
348 	}
349 
350 	if (irq >= IRQ_AMIGA_CIAB) {
351 		cia_able_irq(&ciab_base, 1 << (irq - IRQ_AMIGA_CIAB));
352 		return;
353 	}
354 
355 	if (irq >= IRQ_AMIGA_CIAA) {
356 		cia_able_irq(&ciaa_base, 1 << (irq - IRQ_AMIGA_CIAA));
357 		return;
358 	}
359 
360 	/* disable the interrupt */
361 	amiga_custom.intena = amiga_intena_vals[irq];
362 }
363 
364 inline void amiga_do_irq(int irq, struct pt_regs *fp)
365 {
366 	kstat_cpu(0).irqs[SYS_IRQS + irq]++;
367 	ami_irq_list[irq]->handler(irq, ami_irq_list[irq]->dev_id, fp);
368 }
369 
370 void amiga_do_irq_list(int irq, struct pt_regs *fp)
371 {
372 	irq_node_t *node;
373 
374 	kstat_cpu(0).irqs[SYS_IRQS + irq]++;
375 
376 	amiga_custom.intreq = amiga_intena_vals[irq];
377 
378 	for (node = ami_irq_list[irq]; node; node = node->next)
379 		node->handler(irq, node->dev_id, fp);
380 }
381 
382 /*
383  * The builtin Amiga hardware interrupt handlers.
384  */
385 
386 static irqreturn_t ami_int1(int irq, void *dev_id, struct pt_regs *fp)
387 {
388 	unsigned short ints = amiga_custom.intreqr & amiga_custom.intenar;
389 
390 	/* if serial transmit buffer empty, interrupt */
391 	if (ints & IF_TBE) {
392 		amiga_custom.intreq = IF_TBE;
393 		amiga_do_irq(IRQ_AMIGA_TBE, fp);
394 	}
395 
396 	/* if floppy disk transfer complete, interrupt */
397 	if (ints & IF_DSKBLK) {
398 		amiga_custom.intreq = IF_DSKBLK;
399 		amiga_do_irq(IRQ_AMIGA_DSKBLK, fp);
400 	}
401 
402 	/* if software interrupt set, interrupt */
403 	if (ints & IF_SOFT) {
404 		amiga_custom.intreq = IF_SOFT;
405 		amiga_do_irq(IRQ_AMIGA_SOFT, fp);
406 	}
407 	return IRQ_HANDLED;
408 }
409 
410 static irqreturn_t ami_int3(int irq, void *dev_id, struct pt_regs *fp)
411 {
412 	unsigned short ints = amiga_custom.intreqr & amiga_custom.intenar;
413 
414 	/* if a blitter interrupt */
415 	if (ints & IF_BLIT) {
416 		amiga_custom.intreq = IF_BLIT;
417 		amiga_do_irq(IRQ_AMIGA_BLIT, fp);
418 	}
419 
420 	/* if a copper interrupt */
421 	if (ints & IF_COPER) {
422 		amiga_custom.intreq = IF_COPER;
423 		amiga_do_irq(IRQ_AMIGA_COPPER, fp);
424 	}
425 
426 	/* if a vertical blank interrupt */
427 	if (ints & IF_VERTB)
428 		amiga_do_irq_list(IRQ_AMIGA_VERTB, fp);
429 	return IRQ_HANDLED;
430 }
431 
432 static irqreturn_t ami_int4(int irq, void *dev_id, struct pt_regs *fp)
433 {
434 	unsigned short ints = amiga_custom.intreqr & amiga_custom.intenar;
435 
436 	/* if audio 0 interrupt */
437 	if (ints & IF_AUD0) {
438 		amiga_custom.intreq = IF_AUD0;
439 		amiga_do_irq(IRQ_AMIGA_AUD0, fp);
440 	}
441 
442 	/* if audio 1 interrupt */
443 	if (ints & IF_AUD1) {
444 		amiga_custom.intreq = IF_AUD1;
445 		amiga_do_irq(IRQ_AMIGA_AUD1, fp);
446 	}
447 
448 	/* if audio 2 interrupt */
449 	if (ints & IF_AUD2) {
450 		amiga_custom.intreq = IF_AUD2;
451 		amiga_do_irq(IRQ_AMIGA_AUD2, fp);
452 	}
453 
454 	/* if audio 3 interrupt */
455 	if (ints & IF_AUD3) {
456 		amiga_custom.intreq = IF_AUD3;
457 		amiga_do_irq(IRQ_AMIGA_AUD3, fp);
458 	}
459 	return IRQ_HANDLED;
460 }
461 
462 static irqreturn_t ami_int5(int irq, void *dev_id, struct pt_regs *fp)
463 {
464 	unsigned short ints = amiga_custom.intreqr & amiga_custom.intenar;
465 
466 	/* if serial receive buffer full interrupt */
467 	if (ints & IF_RBF) {
468 		/* acknowledge of IF_RBF must be done by the serial interrupt */
469 		amiga_do_irq(IRQ_AMIGA_RBF, fp);
470 	}
471 
472 	/* if a disk sync interrupt */
473 	if (ints & IF_DSKSYN) {
474 		amiga_custom.intreq = IF_DSKSYN;
475 		amiga_do_irq(IRQ_AMIGA_DSKSYN, fp);
476 	}
477 	return IRQ_HANDLED;
478 }
479 
480 static irqreturn_t ami_int7(int irq, void *dev_id, struct pt_regs *fp)
481 {
482 	panic ("level 7 interrupt received\n");
483 }
484 
485 irqreturn_t (*amiga_default_handler[SYS_IRQS])(int, void *, struct pt_regs *) = {
486 	[0] = ami_badint,
487 	[1] = ami_int1,
488 	[2] = ami_badint,
489 	[3] = ami_int3,
490 	[4] = ami_int4,
491 	[5] = ami_int5,
492 	[6] = ami_badint,
493 	[7] = ami_int7
494 };
495 
496 int show_amiga_interrupts(struct seq_file *p, void *v)
497 {
498 	int i;
499 	irq_node_t *node;
500 
501 	for (i = 0; i < AMI_STD_IRQS; i++) {
502 		if (!(node = ami_irq_list[i]))
503 			continue;
504 		seq_printf(p, "ami  %2d: %10u ", i,
505 		               kstat_cpu(0).irqs[SYS_IRQS + i]);
506 		do {
507 			if (node->flags & SA_INTERRUPT)
508 				seq_puts(p, "F ");
509 			else
510 				seq_puts(p, "  ");
511 			seq_printf(p, "%s\n", node->devname);
512 			if ((node = node->next))
513 				seq_puts(p, "                    ");
514 		} while (node);
515 	}
516 
517 	cia_get_irq_list(&ciaa_base, p);
518 	cia_get_irq_list(&ciab_base, p);
519 	return 0;
520 }
521