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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * arch/m68k/atari/ataints.c -- Atari Linux interrupt handling code
3 *
4 * 5/2/94 Roman Hodek:
5 * Added support for TT interrupts; setup for TT SCU (may someone has
6 * twiddled there and we won't get the right interrupts :-()
7 *
8 * Major change: The device-independent code in m68k/ints.c didn't know
9 * about non-autovec ints yet. It hardcoded the number of possible ints to
10 * 7 (IRQ1...IRQ7). But the Atari has lots of non-autovec ints! I made the
11 * number of possible ints a constant defined in interrupt.h, which is
12 * 47 for the Atari. So we can call request_irq() for all Atari interrupts
13 * just the normal way. Additionally, all vectors >= 48 are initialized to
14 * call trap() instead of inthandler(). This must be changed here, too.
15 *
16 * 1995-07-16 Lars Brinkhoff <f93labr@dd.chalmers.se>:
17 * Corrected a bug in atari_add_isr() which rejected all SCC
18 * interrupt sources if there were no TT MFP!
19 *
20 * 12/13/95: New interface functions atari_level_triggered_int() and
21 * atari_register_vme_int() as support for level triggered VME interrupts.
22 *
23 * 02/12/96: (Roman)
24 * Total rewrite of Atari interrupt handling, for new scheme see comments
25 * below.
26 *
27 * 1996-09-03 lars brinkhoff <f93labr@dd.chalmers.se>:
28 * Added new function atari_unregister_vme_int(), and
29 * modified atari_register_vme_int() as well as IS_VALID_INTNO()
30 * to work with it.
31 *
32 * This file is subject to the terms and conditions of the GNU General Public
33 * License. See the file COPYING in the main directory of this archive
34 * for more details.
35 *
36 */
37
38#include <linux/types.h>
39#include <linux/kernel.h>
40#include <linux/kernel_stat.h>
41#include <linux/init.h>
42#include <linux/seq_file.h>
43
44#include <asm/system.h>
45#include <asm/traps.h>
46
47#include <asm/atarihw.h>
48#include <asm/atariints.h>
49#include <asm/atari_stdma.h>
50#include <asm/irq.h>
51#include <asm/entry.h>
52
53
54/*
55 * Atari interrupt handling scheme:
56 * --------------------------------
57 *
58 * All interrupt source have an internal number (defined in
59 * <asm/atariints.h>): Autovector interrupts are 1..7, then follow ST-MFP,
60 * TT-MFP, SCC, and finally VME interrupts. Vector numbers for the latter can
61 * be allocated by atari_register_vme_int().
62 *
63 * Each interrupt can be of three types:
64 *
65 * - SLOW: The handler runs with all interrupts enabled, except the one it
66 * was called by (to avoid reentering). This should be the usual method.
67 * But it is currently possible only for MFP ints, since only the MFP
68 * offers an easy way to mask interrupts.
69 *
70 * - FAST: The handler runs with all interrupts disabled. This should be used
71 * only for really fast handlers, that just do actions immediately
72 * necessary, and let the rest do a bottom half or task queue.
73 *
74 * - PRIORITIZED: The handler can be interrupted by higher-level ints
75 * (greater IPL, no MFP priorities!). This is the method of choice for ints
76 * which should be slow, but are not from a MFP.
77 *
78 * The feature of more than one handler for one int source is still there, but
79 * only applicable if all handers are of the same type. To not slow down
80 * processing of ints with only one handler by the chaining feature, the list
81 * calling function atari_call_irq_list() is only plugged in at the time the
82 * second handler is registered.
83 *
84 * Implementation notes: For fast-as-possible int handling, there are separate
85 * entry points for each type (slow/fast/prio). The assembler handler calls
86 * the irq directly in the usual case, no C wrapper is involved. In case of
87 * multiple handlers, atari_call_irq_list() is registered as handler and calls
88 * in turn the real irq's. To ease access from assembler level to the irq
89 * function pointer and accompanying data, these two are stored in a separate
90 * array, irq_handler[]. The rest of data (type, name) are put into a second
91 * array, irq_param, that is accessed from C only. For each slow interrupt (32
92 * in all) there are separate handler functions, which makes it possible to
93 * hard-code the MFP register address and value, are necessary to mask the
94 * int. If there'd be only one generic function, lots of calculations would be
95 * needed to determine MFP register and int mask from the vector number :-(
96 *
97 * Furthermore, slow ints may not lower the IPL below its previous value
98 * (before the int happened). This is needed so that an int of class PRIO, on
99 * that this int may be stacked, cannot be reentered. This feature is
100 * implemented as follows: If the stack frame format is 1 (throwaway), the int
101 * is not stacked, and the IPL is anded with 0xfbff, resulting in a new level
102 * 2, which still blocks the HSYNC, but no interrupts of interest. If the
103 * frame format is 0, the int is nested, and the old IPL value can be found in
104 * the sr copy in the frame.
105 */
106
Roman Zippel73408562006-06-25 05:47:03 -0700107#if 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108
109#define NUM_INT_SOURCES (8 + NUM_ATARI_SOURCES)
110
111typedef void (*asm_irq_handler)(void);
112
113struct irqhandler {
114 irqreturn_t (*handler)(int, void *, struct pt_regs *);
115 void *dev_id;
116};
117
118struct irqparam {
119 unsigned long flags;
120 const char *devname;
121};
122
123/*
124 * Array with irq's and their parameter data. This array is accessed from low
125 * level assembler code, so an element size of 8 allows usage of index scaling
126 * addressing mode.
127 */
128static struct irqhandler irq_handler[NUM_INT_SOURCES];
129
130/*
131 * This array hold the rest of parameters of int handlers: type
132 * (slow,fast,prio) and the name of the handler. These values are only
133 * accessed from C
134 */
135static struct irqparam irq_param[NUM_INT_SOURCES];
136
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137/* check for valid int number (complex, sigh...) */
138#define IS_VALID_INTNO(n) \
139 ((n) > 0 && \
140 /* autovec and ST-MFP ok anyway */ \
141 (((n) < TTMFP_SOURCE_BASE) || \
142 /* TT-MFP ok if present */ \
143 ((n) >= TTMFP_SOURCE_BASE && (n) < SCC_SOURCE_BASE && \
144 ATARIHW_PRESENT(TT_MFP)) || \
145 /* SCC ok if present and number even */ \
146 ((n) >= SCC_SOURCE_BASE && (n) < VME_SOURCE_BASE && \
147 !((n) & 1) && ATARIHW_PRESENT(SCC)) || \
148 /* greater numbers ok if they are registered VME vectors */ \
149 ((n) >= VME_SOURCE_BASE && (n) < VME_SOURCE_BASE + VME_MAX_SOURCES && \
150 free_vme_vec_bitmap & (1 << ((n) - VME_SOURCE_BASE)))))
151
152
153/*
154 * Here start the assembler entry points for interrupts
155 */
156
157#define IRQ_NAME(nr) atari_slow_irq_##nr##_handler(void)
158
159#define BUILD_SLOW_IRQ(n) \
160asmlinkage void IRQ_NAME(n); \
161/* Dummy function to allow asm with operands. */ \
162void atari_slow_irq_##n##_dummy (void) { \
163__asm__ (__ALIGN_STR "\n" \
164"atari_slow_irq_" #n "_handler:\t" \
165" addl %6,%5\n" /* preempt_count() += HARDIRQ_OFFSET */ \
166 SAVE_ALL_INT "\n" \
167 GET_CURRENT(%%d0) "\n" \
168" andb #~(1<<(%c3&7)),%a4:w\n" /* mask this interrupt */ \
169 /* get old IPL from stack frame */ \
170" bfextu %%sp@(%c2){#5,#3},%%d0\n" \
171" movew %%sr,%%d1\n" \
172" bfins %%d0,%%d1{#21,#3}\n" \
173" movew %%d1,%%sr\n" /* set IPL = previous value */ \
174" addql #1,%a0\n" \
175" lea %a1,%%a0\n" \
176" pea %%sp@\n" /* push addr of frame */ \
177" movel %%a0@(4),%%sp@-\n" /* push handler data */ \
178" pea (%c3+8)\n" /* push int number */ \
179" movel %%a0@,%%a0\n" \
180" jbsr %%a0@\n" /* call the handler */ \
181" addql #8,%%sp\n" \
182" addql #4,%%sp\n" \
183" orw #0x0600,%%sr\n" \
184" andw #0xfeff,%%sr\n" /* set IPL = 6 again */ \
185" orb #(1<<(%c3&7)),%a4:w\n" /* now unmask the int again */ \
186" jbra ret_from_interrupt\n" \
187 : : "i" (&kstat_cpu(0).irqs[n+8]), "i" (&irq_handler[n+8]), \
188 "n" (PT_OFF_SR), "n" (n), \
189 "i" (n & 8 ? (n & 16 ? &tt_mfp.int_mk_a : &mfp.int_mk_a) \
190 : (n & 16 ? &tt_mfp.int_mk_b : &mfp.int_mk_b)), \
191 "m" (preempt_count()), "di" (HARDIRQ_OFFSET) \
192); \
193 for (;;); /* fake noreturn */ \
194}
195
196BUILD_SLOW_IRQ(0);
197BUILD_SLOW_IRQ(1);
198BUILD_SLOW_IRQ(2);
199BUILD_SLOW_IRQ(3);
200BUILD_SLOW_IRQ(4);
201BUILD_SLOW_IRQ(5);
202BUILD_SLOW_IRQ(6);
203BUILD_SLOW_IRQ(7);
204BUILD_SLOW_IRQ(8);
205BUILD_SLOW_IRQ(9);
206BUILD_SLOW_IRQ(10);
207BUILD_SLOW_IRQ(11);
208BUILD_SLOW_IRQ(12);
209BUILD_SLOW_IRQ(13);
210BUILD_SLOW_IRQ(14);
211BUILD_SLOW_IRQ(15);
212BUILD_SLOW_IRQ(16);
213BUILD_SLOW_IRQ(17);
214BUILD_SLOW_IRQ(18);
215BUILD_SLOW_IRQ(19);
216BUILD_SLOW_IRQ(20);
217BUILD_SLOW_IRQ(21);
218BUILD_SLOW_IRQ(22);
219BUILD_SLOW_IRQ(23);
220BUILD_SLOW_IRQ(24);
221BUILD_SLOW_IRQ(25);
222BUILD_SLOW_IRQ(26);
223BUILD_SLOW_IRQ(27);
224BUILD_SLOW_IRQ(28);
225BUILD_SLOW_IRQ(29);
226BUILD_SLOW_IRQ(30);
227BUILD_SLOW_IRQ(31);
228
229asm_irq_handler slow_handlers[32] = {
230 [0] = atari_slow_irq_0_handler,
231 [1] = atari_slow_irq_1_handler,
232 [2] = atari_slow_irq_2_handler,
233 [3] = atari_slow_irq_3_handler,
234 [4] = atari_slow_irq_4_handler,
235 [5] = atari_slow_irq_5_handler,
236 [6] = atari_slow_irq_6_handler,
237 [7] = atari_slow_irq_7_handler,
238 [8] = atari_slow_irq_8_handler,
239 [9] = atari_slow_irq_9_handler,
240 [10] = atari_slow_irq_10_handler,
241 [11] = atari_slow_irq_11_handler,
242 [12] = atari_slow_irq_12_handler,
243 [13] = atari_slow_irq_13_handler,
244 [14] = atari_slow_irq_14_handler,
245 [15] = atari_slow_irq_15_handler,
246 [16] = atari_slow_irq_16_handler,
247 [17] = atari_slow_irq_17_handler,
248 [18] = atari_slow_irq_18_handler,
249 [19] = atari_slow_irq_19_handler,
250 [20] = atari_slow_irq_20_handler,
251 [21] = atari_slow_irq_21_handler,
252 [22] = atari_slow_irq_22_handler,
253 [23] = atari_slow_irq_23_handler,
254 [24] = atari_slow_irq_24_handler,
255 [25] = atari_slow_irq_25_handler,
256 [26] = atari_slow_irq_26_handler,
257 [27] = atari_slow_irq_27_handler,
258 [28] = atari_slow_irq_28_handler,
259 [29] = atari_slow_irq_29_handler,
260 [30] = atari_slow_irq_30_handler,
261 [31] = atari_slow_irq_31_handler
262};
263
264asmlinkage void atari_fast_irq_handler( void );
265asmlinkage void atari_prio_irq_handler( void );
266
267/* Dummy function to allow asm with operands. */
268void atari_fast_prio_irq_dummy (void) {
269__asm__ (__ALIGN_STR "\n"
270"atari_fast_irq_handler:\n\t"
271 "orw #0x700,%%sr\n" /* disable all interrupts */
272"atari_prio_irq_handler:\n\t"
273 "addl %3,%2\n\t" /* preempt_count() += HARDIRQ_OFFSET */
274 SAVE_ALL_INT "\n\t"
275 GET_CURRENT(%%d0) "\n\t"
276 /* get vector number from stack frame and convert to source */
277 "bfextu %%sp@(%c1){#4,#10},%%d0\n\t"
278 "subw #(0x40-8),%%d0\n\t"
279 "jpl 1f\n\t"
280 "addw #(0x40-8-0x18),%%d0\n"
281 "1:\tlea %a0,%%a0\n\t"
282 "addql #1,%%a0@(%%d0:l:4)\n\t"
283 "lea irq_handler,%%a0\n\t"
284 "lea %%a0@(%%d0:l:8),%%a0\n\t"
285 "pea %%sp@\n\t" /* push frame address */
286 "movel %%a0@(4),%%sp@-\n\t" /* push handler data */
287 "movel %%d0,%%sp@-\n\t" /* push int number */
288 "movel %%a0@,%%a0\n\t"
289 "jsr %%a0@\n\t" /* and call the handler */
290 "addql #8,%%sp\n\t"
291 "addql #4,%%sp\n\t"
292 "jbra ret_from_interrupt"
293 : : "i" (&kstat_cpu(0).irqs), "n" (PT_OFF_FORMATVEC),
294 "m" (preempt_count()), "di" (HARDIRQ_OFFSET)
295);
296 for (;;);
297}
Roman Zippel73408562006-06-25 05:47:03 -0700298#endif
299
300/*
301 * Bitmap for free interrupt vector numbers
302 * (new vectors starting from 0x70 can be allocated by
303 * atari_register_vme_int())
304 */
305static int free_vme_vec_bitmap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306
307/* GK:
308 * HBL IRQ handler for Falcon. Nobody needs it :-)
309 * ++andreas: raise ipl to disable further HBLANK interrupts.
310 */
311asmlinkage void falcon_hblhandler(void);
312asm(".text\n"
313__ALIGN_STR "\n\t"
314"falcon_hblhandler:\n\t"
315 "orw #0x200,%sp@\n\t" /* set saved ipl to 2 */
316 "rte");
317
Roman Zippel73408562006-06-25 05:47:03 -0700318extern void atari_microwire_cmd(int cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319
320extern int atari_SCC_reset_done;
321
Roman Zippel73408562006-06-25 05:47:03 -0700322static int atari_startup_irq(unsigned int irq)
323{
324 m68k_irq_startup(irq);
325 atari_turnon_irq(irq);
326 atari_enable_irq(irq);
327 return 0;
328}
329
330static void atari_shutdown_irq(unsigned int irq)
331{
332 atari_disable_irq(irq);
333 atari_turnoff_irq(irq);
334 m68k_irq_shutdown(irq);
335}
336
337static struct irq_controller atari_irq_controller = {
338 .name = "atari",
339 .lock = SPIN_LOCK_UNLOCKED,
340 .startup = atari_startup_irq,
341 .shutdown = atari_shutdown_irq,
342 .enable = atari_enable_irq,
343 .disable = atari_disable_irq,
344};
345
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346/*
347 * void atari_init_IRQ (void)
348 *
349 * Parameters: None
350 *
351 * Returns: Nothing
352 *
353 * This function should be called during kernel startup to initialize
354 * the atari IRQ handling routines.
355 */
356
357void __init atari_init_IRQ(void)
358{
Roman Zippel73408562006-06-25 05:47:03 -0700359 m68k_setup_user_interrupt(VEC_USER, 192, NULL);
360 m68k_setup_irq_controller(&atari_irq_controller, 1, NUM_ATARI_SOURCES - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361
362 /* Initialize the MFP(s) */
363
364#ifdef ATARI_USE_SOFTWARE_EOI
365 mfp.vec_adr = 0x48; /* Software EOI-Mode */
366#else
367 mfp.vec_adr = 0x40; /* Automatic EOI-Mode */
368#endif
369 mfp.int_en_a = 0x00; /* turn off MFP-Ints */
370 mfp.int_en_b = 0x00;
371 mfp.int_mk_a = 0xff; /* no Masking */
372 mfp.int_mk_b = 0xff;
373
374 if (ATARIHW_PRESENT(TT_MFP)) {
375#ifdef ATARI_USE_SOFTWARE_EOI
376 tt_mfp.vec_adr = 0x58; /* Software EOI-Mode */
377#else
378 tt_mfp.vec_adr = 0x50; /* Automatic EOI-Mode */
379#endif
380 tt_mfp.int_en_a = 0x00; /* turn off MFP-Ints */
381 tt_mfp.int_en_b = 0x00;
382 tt_mfp.int_mk_a = 0xff; /* no Masking */
383 tt_mfp.int_mk_b = 0xff;
384 }
385
386 if (ATARIHW_PRESENT(SCC) && !atari_SCC_reset_done) {
387 scc.cha_a_ctrl = 9;
388 MFPDELAY();
389 scc.cha_a_ctrl = (char) 0xc0; /* hardware reset */
390 }
391
392 if (ATARIHW_PRESENT(SCU)) {
393 /* init the SCU if present */
394 tt_scu.sys_mask = 0x10; /* enable VBL (for the cursor) and
395 * disable HSYNC interrupts (who
396 * needs them?) MFP and SCC are
397 * enabled in VME mask
398 */
399 tt_scu.vme_mask = 0x60; /* enable MFP and SCC ints */
Roman Zippel73408562006-06-25 05:47:03 -0700400 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 /* If no SCU and no Hades, the HSYNC interrupt needs to be
402 * disabled this way. (Else _inthandler in kernel/sys_call.S
403 * gets overruns)
404 */
405
406 if (!MACH_IS_HADES)
407 vectors[VEC_INT2] = falcon_hblhandler;
408 }
409
410 if (ATARIHW_PRESENT(PCM_8BIT) && ATARIHW_PRESENT(MICROWIRE)) {
411 /* Initialize the LM1992 Sound Controller to enable
412 the PSG sound. This is misplaced here, it should
413 be in an atasound_init(), that doesn't exist yet. */
414 atari_microwire_cmd(MW_LM1992_PSG_HIGH);
415 }
416
417 stdma_init();
418
419 /* Initialize the PSG: all sounds off, both ports output */
420 sound_ym.rd_data_reg_sel = 7;
421 sound_ym.wd_data = 0xff;
422}
423
424
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425/*
426 * atari_register_vme_int() returns the number of a free interrupt vector for
427 * hardware with a programmable int vector (probably a VME board).
428 */
429
430unsigned long atari_register_vme_int(void)
431{
432 int i;
433
Roman Zippel73408562006-06-25 05:47:03 -0700434 for (i = 0; i < 32; i++)
435 if ((free_vme_vec_bitmap & (1 << i)) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 break;
437
Roman Zippel73408562006-06-25 05:47:03 -0700438 if (i == 16)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 return 0;
440
441 free_vme_vec_bitmap |= 1 << i;
Roman Zippel73408562006-06-25 05:47:03 -0700442 return VME_SOURCE_BASE + i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443}
444
445
446void atari_unregister_vme_int(unsigned long irq)
447{
Roman Zippel73408562006-06-25 05:47:03 -0700448 if (irq >= VME_SOURCE_BASE && irq < VME_SOURCE_BASE + VME_MAX_SOURCES) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 irq -= VME_SOURCE_BASE;
450 free_vme_vec_bitmap &= ~(1 << irq);
451 }
452}
453
454