4a4ee4dfa6f10f2fb92446f8130709c6c3435110
[linux-2.6.git] / arch / m68k / q40 / q40ints.c
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
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", __FUNCTION__, irq);
51                 return -ENXIO;
52         }
53         return 0;
54 }
55
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,
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
82 void 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
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 irqreturn_t (*q40_timer_routine)(int, void *);
129
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
145 void q40_sched_init (irqreturn_t (*timer_routine)(int, void *))
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 IRQ's*/
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 */
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 occassionally 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
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
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
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 }
328 int q40_probe_irq_off(unsigned long irqs)
329 {
330         return -1;
331 }