summaryrefslogtreecommitdiffstats
path: root/arch/m68k/q40/q40ints.c
blob: 3e7603202977e715a6afc07e4ca0f3d713e0c3ed (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
/*
 * arch/m68k/q40/q40ints.c
 *
 * Copyright (C) 1999,2001 Richard Zidlicky
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 *
 * .. used to be loosely based on bvme6000ints.c
 *
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/irq.h>

#include <asm/ptrace.h>
#include <asm/traps.h>

#include <asm/q40_master.h>
#include <asm/q40ints.h>

/*
 * Q40 IRQs are defined as follows:
 *            3,4,5,6,7,10,11,14,15 : ISA dev IRQs
 *            16-31: reserved
 *            32   : keyboard int
 *            33   : frame int (50/200 Hz periodic timer)
 *            34   : sample int (10/20 KHz periodic timer)
 *
*/

static void q40_irq_handler(unsigned int, struct pt_regs *fp);
static void q40_irq_enable(struct irq_data *data);
static void q40_irq_disable(struct irq_data *data);

unsigned short q40_ablecount[35];
unsigned short q40_state[35];

static unsigned int q40_irq_startup(struct irq_data *data)
{
	unsigned int irq = data->irq;

	/* test for ISA ints not implemented by HW */
	switch (irq) {
	case 1: case 2: case 8: case 9:
	case 11: case 12: case 13:
		pr_warn("%s: ISA IRQ %d not implemented by HW\n", __func__,
			irq);
		/* FIXME return -ENXIO; */
	}
	return 0;
}

static void q40_irq_shutdown(struct irq_data *data)
{
}

static struct irq_chip q40_irq_chip = {
	.name		= "q40",
	.irq_startup	= q40_irq_startup,
	.irq_shutdown	= q40_irq_shutdown,
	.irq_enable	= q40_irq_enable,
	.irq_disable	= q40_irq_disable,
};

/*
 * void q40_init_IRQ (void)
 *
 * Parameters:	None
 *
 * Returns:	Nothing
 *
 * This function is called during kernel startup to initialize
 * the q40 IRQ handling routines.
 */

static int disabled;

void __init q40_init_IRQ(void)
{
	m68k_setup_irq_controller(&q40_irq_chip, handle_simple_irq, 1,
				  Q40_IRQ_MAX);

	/* setup handler for ISA ints */
	m68k_setup_auto_interrupt(q40_irq_handler);

	m68k_irq_startup_irq(IRQ_AUTO_2);
	m68k_irq_startup_irq(IRQ_AUTO_4);

	/* now enable some ints.. */
	master_outb(1, EXT_ENABLE_REG);  /* ISA IRQ 5-15 */

	/* make sure keyboard IRQ is disabled */
	master_outb(0, KEY_IRQ_ENABLE_REG);
}


/*
 * this stuff doesn't really belong here..
 */

int ql_ticks;              /* 200Hz ticks since last jiffie */
static int sound_ticks;

#define SVOL 45

void q40_mksound(unsigned int hz, unsigned int ticks)
{
	/* for now ignore hz, except that hz==0 switches off sound */
	/* simply alternate the ampl (128-SVOL)-(128+SVOL)-..-.. at 200Hz */
	if (hz == 0) {
		if (sound_ticks)
			sound_ticks = 1;

		*DAC_LEFT = 128;
		*DAC_RIGHT = 128;

		return;
	}
	/* sound itself is done in q40_timer_int */
	if (sound_ticks == 0)
		sound_ticks = 1000; /* pretty long beep */
	sound_ticks = ticks << 1;
}

static irq_handler_t q40_timer_routine;

static irqreturn_t q40_timer_int (int irq, void * dev)
{
	ql_ticks = ql_ticks ? 0 : 1;
	if (sound_ticks) {
		unsigned char sval=(sound_ticks & 1) ? 128-SVOL : 128+SVOL;
		sound_ticks--;
		*DAC_LEFT=sval;
		*DAC_RIGHT=sval;
	}

	if (!ql_ticks)
		q40_timer_routine(irq, dev);
	return IRQ_HANDLED;
}

void q40_sched_init (irq_handler_t timer_routine)
{
	int timer_irq;

	q40_timer_routine = timer_routine;
	timer_irq = Q40_IRQ_FRAME;

	if (request_irq(timer_irq, q40_timer_int, 0,
				"timer", q40_timer_int))
		panic("Couldn't register timer int");

	master_outb(-1, FRAME_CLEAR_REG);
	master_outb( 1, FRAME_RATE_REG);
}


/*
 * tables to translate bits into IRQ numbers
 * it is a good idea to order the entries by priority
 *
*/

struct IRQ_TABLE{ unsigned mask; int irq ;};
#if 0
static struct IRQ_TABLE iirqs[]={
  {Q40_IRQ_FRAME_MASK,Q40_IRQ_FRAME},
  {Q40_IRQ_KEYB_MASK,Q40_IRQ_KEYBOARD},
  {0,0}};
#endif
static struct IRQ_TABLE eirqs[] = {
  { .mask = Q40_IRQ3_MASK,	.irq = 3 },	/* ser 1 */
  { .mask = Q40_IRQ4_MASK,	.irq = 4 },	/* ser 2 */
  { .mask = Q40_IRQ14_MASK,	.irq = 14 },	/* IDE 1 */
  { .mask = Q40_IRQ15_MASK,	.irq = 15 },	/* IDE 2 */
  { .mask = Q40_IRQ6_MASK,	.irq = 6 },	/* floppy, handled elsewhere */
  { .mask = Q40_IRQ7_MASK,	.irq = 7 },	/* par */
  { .mask = Q40_IRQ5_MASK,	.irq = 5 },
  { .mask = Q40_IRQ10_MASK,	.irq = 10 },
  {0,0}
};

/* complain only this many times about spurious ints : */
static int ccleirq=60;    /* ISA dev IRQs*/
/*static int cclirq=60;*/     /* internal */

/* FIXME: add shared ints,mask,unmask,probing.... */

#define IRQ_INPROGRESS 1
/*static unsigned short saved_mask;*/
//static int do_tint=0;

#define DEBUG_Q40INT
/*#define IP_USE_DISABLE *//* would be nice, but crashes ???? */

static int mext_disabled=0;  /* ext irq disabled by master chip? */
static int aliased_irq=0;  /* how many times inside handler ?*/


/* got interrupt, dispatch to ISA or keyboard/timer IRQs */
static void q40_irq_handler(unsigned int irq, struct pt_regs *fp)
{
	unsigned mir, mer;
	int i;

//repeat:
	mir = master_inb(IIRQ_REG);
#ifdef CONFIG_BLK_DEV_FD
	if ((mir & Q40_IRQ_EXT_MASK) &&
	    (master_inb(EIRQ_REG) & Q40_IRQ6_MASK)) {
		floppy_hardint();
		return;
	}
#endif
	switch (irq) {
	case 4:
	case 6:
		do_IRQ(Q40_IRQ_SAMPLE, fp);
		return;
	}
	if (mir & Q40_IRQ_FRAME_MASK) {
		do_IRQ(Q40_IRQ_FRAME, fp);
		master_outb(-1, FRAME_CLEAR_REG);
	}
	if ((mir & Q40_IRQ_SER_MASK) || (mir & Q40_IRQ_EXT_MASK)) {
		mer = master_inb(EIRQ_REG);
		for (i = 0; eirqs[i].mask; i++) {
			if (mer & eirqs[i].mask) {
				irq = eirqs[i].irq;
/*
 * There is a little mess wrt which IRQ really caused this irq request. The
 * main problem is that IIRQ_REG and EIRQ_REG reflect the state when they
 * are read - which is long after the request came in. In theory IRQs should
 * not just go away but they occasionally do
 */
				if (irq > 4 && irq <= 15 && mext_disabled) {
					/*aliased_irq++;*/
					goto iirq;
				}
				if (q40_state[irq] & IRQ_INPROGRESS) {
					/* some handlers do local_irq_enable() for irq latency reasons, */
					/* however reentering an active irq handler is not permitted */
#ifdef IP_USE_DISABLE
					/* in theory this is the better way to do it because it still */
					/* lets through eg the serial irqs, unfortunately it crashes */
					disable_irq(irq);
					disabled = 1;
#else
					/*pr_warn("IRQ_INPROGRESS detected for irq %d, disabling - %s disabled\n",
						irq, disabled ? "already" : "not yet"); */
					fp->sr = (((fp->sr) & (~0x700))+0x200);
					disabled = 1;
#endif
					goto iirq;
				}
				q40_state[irq] |= IRQ_INPROGRESS;
				do_IRQ(irq, fp);
				q40_state[irq] &= ~IRQ_INPROGRESS;

				/* naively enable everything, if that fails than    */
				/* this function will be reentered immediately thus */
				/* getting another chance to disable the IRQ        */

				if (disabled) {
#ifdef IP_USE_DISABLE
					if (irq > 4) {
						disabled = 0;
						enable_irq(irq);
					}
#else
					disabled = 0;
					/*pr_info("reenabling irq %d\n", irq); */
#endif
				}
// used to do 'goto repeat;' here, this delayed bh processing too long
				return;
			}
		}
		if (mer && ccleirq > 0 && !aliased_irq) {
			pr_warn("ISA interrupt from unknown source? EIRQ_REG = %x\n",
				mer);
			ccleirq--;
		}
	}
 iirq:
	mir = master_inb(IIRQ_REG);
	/* should test whether keyboard irq is really enabled, doing it in defhand */
	if (mir & Q40_IRQ_KEYB_MASK)
		do_IRQ(Q40_IRQ_KEYBOARD, fp);

	return;
}

void q40_irq_enable(struct irq_data *data)
{
	unsigned int irq = data->irq;

	if (irq >= 5 && irq <= 15) {
		mext_disabled--;
		if (mext_disabled > 0)
			pr_warn("q40_irq_enable : nested disable/enable\n");
		if (mext_disabled == 0)
			master_outb(1, EXT_ENABLE_REG);
	}
}


void q40_irq_disable(struct irq_data *data)
{
	unsigned int irq = data->irq;

	/* disable ISA iqs : only do something if the driver has been
	 * verified to be Q40 "compatible" - right now IDE, NE2K
	 * Any driver should not attempt to sleep across disable_irq !!
	 */

	if (irq >= 5 && irq <= 15) {
		master_outb(0, EXT_ENABLE_REG);
		mext_disabled++;
		if (mext_disabled > 1)
			pr_info("disable_irq nesting count %d\n",
				mext_disabled);
	}
}