xref: /linux/arch/m68k/atari/ataints.c (revision 906fd46a65383cd639e5eec72a047efc33045d86)
1 /*
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 #include <linux/module.h>
44 #include <linux/irq.h>
45 
46 #include <asm/traps.h>
47 
48 #include <asm/atarihw.h>
49 #include <asm/atariints.h>
50 #include <asm/atari_stdma.h>
51 #include <asm/irq.h>
52 #include <asm/entry.h>
53 #include <asm/io.h>
54 
55 #include "atari.h"
56 
57 /*
58  * Atari interrupt handling scheme:
59  * --------------------------------
60  *
61  * All interrupt source have an internal number (defined in
62  * <asm/atariints.h>): Autovector interrupts are 1..7, then follow ST-MFP,
63  * TT-MFP, SCC, and finally VME interrupts. Vector numbers for the latter can
64  * be allocated by atari_register_vme_int().
65  */
66 
67 /*
68  * Bitmap for free interrupt vector numbers
69  * (new vectors starting from 0x70 can be allocated by
70  * atari_register_vme_int())
71  */
72 static int free_vme_vec_bitmap;
73 
74 /* GK:
75  * HBL IRQ handler for Falcon. Nobody needs it :-)
76  * ++andreas: raise ipl to disable further HBLANK interrupts.
77  */
78 asmlinkage void falcon_hblhandler(void);
79 asm(".text\n"
80 __ALIGN_STR "\n\t"
81 "falcon_hblhandler:\n\t"
82 	"orw	#0x200,%sp@\n\t"	/* set saved ipl to 2 */
83 	"rte");
84 
85 static unsigned int atari_irq_startup(struct irq_data *data)
86 {
87 	unsigned int irq = data->irq;
88 
89 	m68k_irq_startup(data);
90 	atari_turnon_irq(irq);
91 	atari_enable_irq(irq);
92 	return 0;
93 }
94 
95 static void atari_irq_shutdown(struct irq_data *data)
96 {
97 	unsigned int irq = data->irq;
98 
99 	atari_disable_irq(irq);
100 	atari_turnoff_irq(irq);
101 	m68k_irq_shutdown(data);
102 
103 	if (irq == IRQ_AUTO_4)
104 	    vectors[VEC_INT4] = falcon_hblhandler;
105 }
106 
107 static void atari_irq_enable(struct irq_data *data)
108 {
109 	atari_enable_irq(data->irq);
110 }
111 
112 static void atari_irq_disable(struct irq_data *data)
113 {
114 	atari_disable_irq(data->irq);
115 }
116 
117 static struct irq_chip atari_irq_chip = {
118 	.name		= "atari",
119 	.irq_startup	= atari_irq_startup,
120 	.irq_shutdown	= atari_irq_shutdown,
121 	.irq_enable	= atari_irq_enable,
122 	.irq_disable	= atari_irq_disable,
123 };
124 
125 /*
126  * ST-MFP timer D chained interrupts - each driver gets its own timer
127  * interrupt instance.
128  */
129 
130 struct mfptimerbase {
131 	volatile struct MFP *mfp;
132 	unsigned char mfp_mask, mfp_data;
133 	unsigned short int_mask;
134 	int handler_irq, mfptimer_irq, server_irq;
135 	char *name;
136 } stmfp_base = {
137 	.mfp		= &st_mfp,
138 	.int_mask	= 0x0,
139 	.handler_irq	= IRQ_MFP_TIMD,
140 	.mfptimer_irq	= IRQ_MFP_TIMER1,
141 	.name		= "MFP Timer D"
142 };
143 
144 static irqreturn_t mfp_timer_d_handler(int irq, void *dev_id)
145 {
146 	struct mfptimerbase *base = dev_id;
147 	int mach_irq;
148 	unsigned char ints;
149 
150 	mach_irq = base->mfptimer_irq;
151 	ints = base->int_mask;
152 	for (; ints; mach_irq++, ints >>= 1) {
153 		if (ints & 1)
154 			generic_handle_irq(mach_irq);
155 	}
156 	return IRQ_HANDLED;
157 }
158 
159 
160 static void atari_mfptimer_enable(struct irq_data *data)
161 {
162 	int mfp_num = data->irq - IRQ_MFP_TIMER1;
163 	stmfp_base.int_mask |= 1 << mfp_num;
164 	atari_enable_irq(IRQ_MFP_TIMD);
165 }
166 
167 static void atari_mfptimer_disable(struct irq_data *data)
168 {
169 	int mfp_num = data->irq - IRQ_MFP_TIMER1;
170 	stmfp_base.int_mask &= ~(1 << mfp_num);
171 	if (!stmfp_base.int_mask)
172 		atari_disable_irq(IRQ_MFP_TIMD);
173 }
174 
175 static struct irq_chip atari_mfptimer_chip = {
176 	.name		= "timer_d",
177 	.irq_enable	= atari_mfptimer_enable,
178 	.irq_disable	= atari_mfptimer_disable,
179 };
180 
181 
182 /*
183  * EtherNAT CPLD interrupt handling
184  * CPLD interrupt register is at phys. 0x80000023
185  * Need this mapped in at interrupt startup time
186  * Possibly need this mapped on demand anyway -
187  * EtherNAT USB driver needs to disable IRQ before
188  * startup!
189  */
190 
191 static unsigned char *enat_cpld;
192 
193 static unsigned int atari_ethernat_startup(struct irq_data *data)
194 {
195 	int enat_num = 140 - data->irq + 1;
196 
197 	m68k_irq_startup(data);
198 	/*
199 	* map CPLD interrupt register
200 	*/
201 	if (!enat_cpld)
202 		enat_cpld = (unsigned char *)ioremap((ATARI_ETHERNAT_PHYS_ADDR+0x23), 0x2);
203 	/*
204 	 * do _not_ enable the USB chip interrupt here - causes interrupt storm
205 	 * and triggers dead interrupt watchdog
206 	 * Need to reset the USB chip to a sane state in early startup before
207 	 * removing this hack
208 	 */
209 	if (enat_num == 1)
210 		*enat_cpld |= 1 << enat_num;
211 
212 	return 0;
213 }
214 
215 static void atari_ethernat_enable(struct irq_data *data)
216 {
217 	int enat_num = 140 - data->irq + 1;
218 	/*
219 	* map CPLD interrupt register
220 	*/
221 	if (!enat_cpld)
222 		enat_cpld = (unsigned char *)ioremap((ATARI_ETHERNAT_PHYS_ADDR+0x23), 0x2);
223 	*enat_cpld |= 1 << enat_num;
224 }
225 
226 static void atari_ethernat_disable(struct irq_data *data)
227 {
228 	int enat_num = 140 - data->irq + 1;
229 	/*
230 	* map CPLD interrupt register
231 	*/
232 	if (!enat_cpld)
233 		enat_cpld = (unsigned char *)ioremap((ATARI_ETHERNAT_PHYS_ADDR+0x23), 0x2);
234 	*enat_cpld &= ~(1 << enat_num);
235 }
236 
237 static void atari_ethernat_shutdown(struct irq_data *data)
238 {
239 	int enat_num = 140 - data->irq + 1;
240 	if (enat_cpld) {
241 		*enat_cpld &= ~(1 << enat_num);
242 		iounmap(enat_cpld);
243 		enat_cpld = NULL;
244 	}
245 }
246 
247 static struct irq_chip atari_ethernat_chip = {
248 	.name		= "ethernat",
249 	.irq_startup	= atari_ethernat_startup,
250 	.irq_shutdown	= atari_ethernat_shutdown,
251 	.irq_enable	= atari_ethernat_enable,
252 	.irq_disable	= atari_ethernat_disable,
253 };
254 
255 /*
256  * void atari_init_IRQ (void)
257  *
258  * Parameters:	None
259  *
260  * Returns:	Nothing
261  *
262  * This function should be called during kernel startup to initialize
263  * the atari IRQ handling routines.
264  */
265 
266 void __init atari_init_IRQ(void)
267 {
268 	m68k_setup_user_interrupt(VEC_USER, NUM_ATARI_SOURCES - IRQ_USER);
269 	m68k_setup_irq_controller(&atari_irq_chip, handle_simple_irq, 1,
270 				  NUM_ATARI_SOURCES - 1);
271 
272 	/* Initialize the MFP(s) */
273 
274 #ifdef ATARI_USE_SOFTWARE_EOI
275 	st_mfp.vec_adr  = 0x48;	/* Software EOI-Mode */
276 #else
277 	st_mfp.vec_adr  = 0x40;	/* Automatic EOI-Mode */
278 #endif
279 	st_mfp.int_en_a = 0x00;	/* turn off MFP-Ints */
280 	st_mfp.int_en_b = 0x00;
281 	st_mfp.int_mk_a = 0xff;	/* no Masking */
282 	st_mfp.int_mk_b = 0xff;
283 
284 	if (ATARIHW_PRESENT(TT_MFP)) {
285 #ifdef ATARI_USE_SOFTWARE_EOI
286 		tt_mfp.vec_adr  = 0x58;		/* Software EOI-Mode */
287 #else
288 		tt_mfp.vec_adr  = 0x50;		/* Automatic EOI-Mode */
289 #endif
290 		tt_mfp.int_en_a = 0x00;		/* turn off MFP-Ints */
291 		tt_mfp.int_en_b = 0x00;
292 		tt_mfp.int_mk_a = 0xff;		/* no Masking */
293 		tt_mfp.int_mk_b = 0xff;
294 	}
295 
296 	if (ATARIHW_PRESENT(SCC) && !atari_SCC_reset_done) {
297 		atari_scc.cha_a_ctrl = 9;
298 		MFPDELAY();
299 		atari_scc.cha_a_ctrl = (char) 0xc0; /* hardware reset */
300 	}
301 
302 	if (ATARIHW_PRESENT(SCU)) {
303 		/* init the SCU if present */
304 		tt_scu.sys_mask = 0x10;		/* enable VBL (for the cursor) and
305 									 * disable HSYNC interrupts (who
306 									 * needs them?)  MFP and SCC are
307 									 * enabled in VME mask
308 									 */
309 		tt_scu.vme_mask = 0x60;		/* enable MFP and SCC ints */
310 	} else {
311 		/* If no SCU and no Hades, the HSYNC interrupt needs to be
312 		 * disabled this way. (Else _inthandler in kernel/sys_call.S
313 		 * gets overruns)
314 		 */
315 
316 		vectors[VEC_INT2] = falcon_hblhandler;
317 		vectors[VEC_INT4] = falcon_hblhandler;
318 	}
319 
320 	if (ATARIHW_PRESENT(PCM_8BIT) && ATARIHW_PRESENT(MICROWIRE)) {
321 		/* Initialize the LM1992 Sound Controller to enable
322 		   the PSG sound.  This is misplaced here, it should
323 		   be in an atasound_init(), that doesn't exist yet. */
324 		atari_microwire_cmd(MW_LM1992_PSG_HIGH);
325 	}
326 
327 	stdma_init();
328 
329 	/* Initialize the PSG: all sounds off, both ports output */
330 	sound_ym.rd_data_reg_sel = 7;
331 	sound_ym.wd_data = 0xff;
332 
333 	m68k_setup_irq_controller(&atari_mfptimer_chip, handle_simple_irq,
334 				  IRQ_MFP_TIMER1, 8);
335 
336 	irq_set_status_flags(IRQ_MFP_TIMER1, IRQ_IS_POLLED);
337 	irq_set_status_flags(IRQ_MFP_TIMER2, IRQ_IS_POLLED);
338 
339 	/* prepare timer D data for use as poll interrupt */
340 	/* set Timer D data Register - needs to be > 0 */
341 	st_mfp.tim_dt_d = 254;	/* < 100 Hz */
342 	/* start timer D, div = 1:100 */
343 	st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 0xf0) | 0x6;
344 
345 	/* request timer D dispatch handler */
346 	if (request_irq(IRQ_MFP_TIMD, mfp_timer_d_handler, IRQF_SHARED,
347 			stmfp_base.name, &stmfp_base))
348 		pr_err("Couldn't register %s interrupt\n", stmfp_base.name);
349 
350 	/*
351 	 * EtherNAT ethernet / USB interrupt handlers
352 	 */
353 
354 	m68k_setup_irq_controller(&atari_ethernat_chip, handle_simple_irq,
355 				  139, 2);
356 }
357 
358 
359 /*
360  * atari_register_vme_int() returns the number of a free interrupt vector for
361  * hardware with a programmable int vector (probably a VME board).
362  */
363 
364 unsigned int atari_register_vme_int(void)
365 {
366 	int i;
367 
368 	for (i = 0; i < 32; i++)
369 		if ((free_vme_vec_bitmap & (1 << i)) == 0)
370 			break;
371 
372 	if (i == 16)
373 		return 0;
374 
375 	free_vme_vec_bitmap |= 1 << i;
376 	return VME_SOURCE_BASE + i;
377 }
378 EXPORT_SYMBOL(atari_register_vme_int);
379 
380 
381 void atari_unregister_vme_int(unsigned int irq)
382 {
383 	if (irq >= VME_SOURCE_BASE && irq < VME_SOURCE_BASE + VME_MAX_SOURCES) {
384 		irq -= VME_SOURCE_BASE;
385 		free_vme_vec_bitmap &= ~(1 << irq);
386 	}
387 }
388 EXPORT_SYMBOL(atari_unregister_vme_int);
389 
390 
391