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/config.h>
39 #include <linux/types.h>
40 #include <linux/kernel.h>
41 #include <linux/sched.h>
42 #include <linux/interrupt.h>
43 #include <linux/irq.h>
44 #include <linux/kernel_stat.h>
45 #include <linux/init.h>
46 
47 #include <asm/system.h>
48 #include <asm/irq.h>
49 #include <asm/traps.h>
50 #include <asm/amigahw.h>
51 #include <asm/amigaints.h>
52 #include <asm/amipcmcia.h>
53 
54 #ifdef CONFIG_APUS
55 #include <asm/amigappc.h>
56 #endif
57 
58 extern int cia_request_irq(int irq,
59                            void (*handler)(int, void *, struct pt_regs *),
60                            unsigned long flags, const char *devname, void *dev_id);
61 extern void cia_free_irq(unsigned int irq, void *dev_id);
62 extern void cia_init_IRQ(struct ciabase *base);
63 extern int cia_get_irq_list(struct ciabase *base, char *buf);
64 
65 unsigned short ami_intena_vals[AMI_STD_IRQS] = {
66 	IF_VERTB, IF_COPER, IF_AUD0, IF_AUD1, IF_AUD2, IF_AUD3, IF_BLIT,
67 	IF_DSKSYN, IF_DSKBLK, IF_RBF, IF_TBE, IF_SOFT, IF_PORTS, IF_EXTER
68 };
69 static const unsigned char ami_servers[AMI_STD_IRQS] = {
70 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1
71 };
72 
73 static short ami_ablecount[AMI_IRQS];
74 
ami_badint(int irq,void * dev_id,struct pt_regs * fp)75 static void ami_badint(int irq, void *dev_id, struct pt_regs *fp)
76 {
77 /*	num_spurious += 1;*/
78 }
79 
80 /*
81  * void amiga_init_IRQ(void)
82  *
83  * Parameters:	None
84  *
85  * Returns:	Nothing
86  *
87  * This function should be called during kernel startup to initialize
88  * the amiga IRQ handling routines.
89  */
90 
91 __init
amiga_init_IRQ(void)92 void amiga_init_IRQ(void)
93 {
94 	int i;
95 
96 	for (i = 0; i < AMI_IRQS; i++)
97 		ami_ablecount[i] = 0;
98 
99 	/* turn off PCMCIA interrupts */
100 	if (AMIGAHW_PRESENT(PCMCIA))
101 		gayle.inten = GAYLE_IRQ_IDE;
102 
103 	/* turn off all interrupts... */
104 	custom.intena = 0x7fff;
105 	custom.intreq = 0x7fff;
106 
107 #ifdef CONFIG_APUS
108 	/* Clear any inter-CPU interrupt requests. Circumvents bug in
109            Blizzard IPL emulation HW (or so it appears). */
110 	APUS_WRITE(APUS_INT_LVL, INTLVL_SETRESET | INTLVL_MASK);
111 
112 	/* Init IPL emulation. */
113 	APUS_WRITE(APUS_REG_INT, REGINT_INTMASTER | REGINT_ENABLEIPL);
114 	APUS_WRITE(APUS_IPL_EMU, IPLEMU_DISABLEINT);
115 	APUS_WRITE(APUS_IPL_EMU, IPLEMU_SETRESET | IPLEMU_IPLMASK);
116 #endif
117 	/* ... and enable the master interrupt bit */
118 	custom.intena = IF_SETCLR | IF_INTEN;
119 
120 	cia_init_IRQ(&ciaa_base);
121 	cia_init_IRQ(&ciab_base);
122 }
123 
124 /*
125  * Enable/disable a particular machine specific interrupt source.
126  * Note that this may affect other interrupts in case of a shared interrupt.
127  * This function should only be called for a _very_ short time to change some
128  * internal data, that may not be changed by the interrupt at the same time.
129  * ami_(enable|disable)_irq calls may also be nested.
130  */
131 
amiga_enable_irq(unsigned int irq)132 void amiga_enable_irq(unsigned int irq)
133 {
134 	if (irq >= AMI_IRQS) {
135 		printk("%s: Unknown IRQ %d\n", __FUNCTION__, irq);
136 		return;
137 	}
138 
139 	ami_ablecount[irq]--;
140 	if (ami_ablecount[irq]<0)
141 		ami_ablecount[irq]=0;
142 	else if (ami_ablecount[irq])
143 		return;
144 
145 	/* No action for auto-vector interrupts */
146 	if (irq >= IRQ_AMIGA_AUTO){
147 		printk("%s: Trying to enable auto-vector IRQ %i\n",
148 		       __FUNCTION__, irq - IRQ_AMIGA_AUTO);
149 		return;
150 	}
151 
152 	if (irq >= IRQ_AMIGA_CIAA) {
153 		cia_set_irq(irq, 0);
154 		cia_able_irq(irq, 1);
155 		return;
156 	}
157 
158 	/* enable the interrupt */
159 	custom.intena = IF_SETCLR | ami_intena_vals[irq];
160 }
161 
amiga_disable_irq(unsigned int irq)162 void amiga_disable_irq(unsigned int irq)
163 {
164 	if (irq >= AMI_IRQS) {
165 		printk("%s: Unknown IRQ %d\n", __FUNCTION__, irq);
166 		return;
167 	}
168 
169 	if (ami_ablecount[irq]++)
170 		return;
171 
172 	/* No action for auto-vector interrupts */
173 	if (irq >= IRQ_AMIGA_AUTO) {
174 		printk("%s: Trying to disable auto-vector IRQ %i\n",
175 		       __FUNCTION__, irq - IRQ_AMIGA_AUTO);
176 		return;
177 	}
178 
179 	if (irq >= IRQ_AMIGA_CIAA) {
180 		cia_able_irq(irq, 0);
181 		return;
182 	}
183 
184 	/* disable the interrupt */
185 	custom.intena = ami_intena_vals[irq];
186 }
187 
amiga_do_irq(int irq,struct pt_regs * fp)188 inline void amiga_do_irq(int irq, struct pt_regs *fp)
189 {
190 	irq_desc_t *desc = irq_desc + irq;
191 	struct irqaction *action = desc->action;
192 
193 	kstat.irqs[0][irq]++;
194 	action->handler(irq, action->dev_id, fp);
195 }
196 
amiga_do_irq_list(int irq,struct pt_regs * fp)197 void amiga_do_irq_list(int irq, struct pt_regs *fp)
198 {
199 	irq_desc_t *desc = irq_desc + irq;
200 	struct irqaction *action;
201 
202 	kstat.irqs[0][irq]++;
203 
204 	custom.intreq = ami_intena_vals[irq];
205 
206 	for (action = desc->action; action; action = action->next)
207 		action->handler(irq, action->dev_id, fp);
208 }
209 
210 /*
211  * The builtin Amiga hardware interrupt handlers.
212  */
213 
ami_int1(int irq,void * dev_id,struct pt_regs * fp)214 static void ami_int1(int irq, void *dev_id, struct pt_regs *fp)
215 {
216 	unsigned short ints = custom.intreqr & custom.intenar;
217 
218 	/* if serial transmit buffer empty, interrupt */
219 	if (ints & IF_TBE) {
220 		custom.intreq = IF_TBE;
221 		amiga_do_irq(IRQ_AMIGA_TBE, fp);
222 	}
223 
224 	/* if floppy disk transfer complete, interrupt */
225 	if (ints & IF_DSKBLK) {
226 		custom.intreq = IF_DSKBLK;
227 		amiga_do_irq(IRQ_AMIGA_DSKBLK, fp);
228 	}
229 
230 	/* if software interrupt set, interrupt */
231 	if (ints & IF_SOFT) {
232 		custom.intreq = IF_SOFT;
233 		amiga_do_irq(IRQ_AMIGA_SOFT, fp);
234 	}
235 }
236 
ami_int3(int irq,void * dev_id,struct pt_regs * fp)237 static void ami_int3(int irq, void *dev_id, struct pt_regs *fp)
238 {
239 	unsigned short ints = custom.intreqr & custom.intenar;
240 
241 	/* if a blitter interrupt */
242 	if (ints & IF_BLIT) {
243 		custom.intreq = IF_BLIT;
244 		amiga_do_irq(IRQ_AMIGA_BLIT, fp);
245 	}
246 
247 	/* if a copper interrupt */
248 	if (ints & IF_COPER) {
249 		custom.intreq = IF_COPER;
250 		amiga_do_irq(IRQ_AMIGA_COPPER, fp);
251 	}
252 
253 	/* if a vertical blank interrupt */
254 	if (ints & IF_VERTB)
255 		amiga_do_irq_list(IRQ_AMIGA_VERTB, fp);
256 }
257 
ami_int4(int irq,void * dev_id,struct pt_regs * fp)258 static void ami_int4(int irq, void *dev_id, struct pt_regs *fp)
259 {
260 	unsigned short ints = custom.intreqr & custom.intenar;
261 
262 	/* if audio 0 interrupt */
263 	if (ints & IF_AUD0) {
264 		custom.intreq = IF_AUD0;
265 		amiga_do_irq(IRQ_AMIGA_AUD0, fp);
266 	}
267 
268 	/* if audio 1 interrupt */
269 	if (ints & IF_AUD1) {
270 		custom.intreq = IF_AUD1;
271 		amiga_do_irq(IRQ_AMIGA_AUD1, fp);
272 	}
273 
274 	/* if audio 2 interrupt */
275 	if (ints & IF_AUD2) {
276 		custom.intreq = IF_AUD2;
277 		amiga_do_irq(IRQ_AMIGA_AUD2, fp);
278 	}
279 
280 	/* if audio 3 interrupt */
281 	if (ints & IF_AUD3) {
282 		custom.intreq = IF_AUD3;
283 		amiga_do_irq(IRQ_AMIGA_AUD3, fp);
284 	}
285 }
286 
ami_int5(int irq,void * dev_id,struct pt_regs * fp)287 static void ami_int5(int irq, void *dev_id, struct pt_regs *fp)
288 {
289 	unsigned short ints = custom.intreqr & custom.intenar;
290 
291 	/* if serial receive buffer full interrupt */
292 	if (ints & IF_RBF) {
293 		/* acknowledge of IF_RBF must be done by the serial interrupt */
294 		amiga_do_irq(IRQ_AMIGA_RBF, fp);
295 	}
296 
297 	/* if a disk sync interrupt */
298 	if (ints & IF_DSKSYN) {
299 		custom.intreq = IF_DSKSYN;
300 		amiga_do_irq(IRQ_AMIGA_DSKSYN, fp);
301 	}
302 }
303 
ami_int7(int irq,void * dev_id,struct pt_regs * fp)304 static void ami_int7(int irq, void *dev_id, struct pt_regs *fp)
305 {
306 	panic ("level 7 interrupt received\n");
307 }
308 
309 #ifdef CONFIG_APUS
310 /* The PPC irq handling links all handlers requested on the same vector
311    and executes them in a loop. Having ami_badint at the end of the chain
312    is a bad idea. */
313 struct irqaction amiga_sys_irqaction[AUTO_IRQS] = {
314 	{ handler: ami_badint, name: "spurious int" },
315 	{ handler: ami_int1, name: "int1 handler" },
316 	{ 0, /* CIAA */ },
317 	{ handler: ami_int3, name: "int3 handler" },
318 	{ handler: ami_int4, name: "int4 handler" },
319 	{ handler: ami_int5, name: "int5 handler" },
320 	{ 0, /* CIAB */ },
321 	{ handler: ami_int7, name: "int7 handler" },
322 };
323 #else
324 void (*amiga_default_handler[SYS_IRQS])(int, void *, struct pt_regs *) = {
325 	ami_badint, ami_int1, ami_badint, ami_int3,
326 	ami_int4, ami_int5, ami_badint, ami_int7
327 };
328 #endif
329