xref: /netbsd-src/sys/arch/atari/isa/isa_milan.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: isa_milan.c,v 1.8 2005/12/11 12:16:59 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2001 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Leo Weppelman.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the NetBSD
21  *	Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: isa_milan.c,v 1.8 2005/12/11 12:16:59 christos Exp $");
41 
42 #include <sys/types.h>
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/device.h>
46 
47 #include <dev/isa/isavar.h>
48 #include <dev/isa/isareg.h>
49 
50 #include <machine/iomap.h>
51 
52 void	isa_bus_init(void);
53 
54 static void new_imask(void);
55 static void isa_callback(int);
56 
57 /*
58  * Bitmask of currently enabled isa interrupts. Used by new_imask().
59  */
60 static u_int16_t imask_enable = 0xffff;
61 
62 #define	IRQ_SLAVE		2	/* Slave at level 2		*/
63 #define MILAN_MAX_ISA_INTS	16	/* Max. number of vectors	*/
64 #define	ICU_OFFSET		0	/* Interrupt vector base	*/
65 
66 #define	WICU(icu, val)		*(volatile u_int8_t*)(icu) = val
67 
68 static isa_intr_info_t milan_isa_iinfo[MILAN_MAX_ISA_INTS];
69 
70 void
71 isa_bus_init()
72 {
73 	volatile u_int8_t	*icu;
74 
75 	/*
76 	 * Initialize both the icu's:
77 	 *   - enter Special Mask Mode
78 	 *   - Block all interrupts
79 	 */
80 	icu = (u_int8_t*)(AD_8259_MASTER);
81 
82 	icu[0] = 0x11;			/* reset; program device, four bytes */
83 	icu[1] = ICU_OFFSET;		/* starting at this vector index */
84 	icu[1] = (1 << IRQ_SLAVE);	/* slave on line 2 */
85 	icu[1] = 1;			/* 8086 mode */
86 	icu[1] = 0xff;			/* leave interrupts masked */
87 	icu[0] = 0x68;			/* special mask mode  */
88 	icu[0] = 0x0a;			/* Read IRR by default. */
89 
90 	icu = (u_int8_t*)(AD_8259_SLAVE);
91 
92 	icu[0] = 0x11;			/* reset; program device, four bytes */
93 	icu[1] = ICU_OFFSET + 8;	/* starting at this vector index */
94 	icu[1] = IRQ_SLAVE;		/* slave on line 2 */
95 	icu[1] = 1;			/* 8086 mode */
96 	icu[1] = 0xff;			/* leave interrupts masked */
97 	icu[0] = 0x68;			/* special mask mode  */
98 	icu[0] = 0x0a;			/* Read IRR by default. */
99 }
100 
101 /*
102  * Determine and activate new interrupt mask by scanning the milan_isa_iinfo
103  * array for enabled interrupts.
104  */
105 static void
106 new_imask()
107 {
108 	int		irq;
109 	u_int16_t	nmask = 0;
110 
111 	for (irq = 0; irq < MILAN_MAX_ISA_INTS; irq++) {
112 		if (milan_isa_iinfo[irq].ifunc != NULL)
113 			nmask |= 1 << irq;
114 		if (nmask >= 0x100)
115 			nmask |= 1 << IRQ_SLAVE;
116 	}
117 	imask_enable = ~nmask;
118 	WICU(AD_8259_MASTER+1, imask_enable & 0xff);
119 	WICU(AD_8259_SLAVE+1 , (imask_enable >> 8) & 0xff);
120 }
121 
122 static void
123 isa_callback(vector)
124 	int	vector;
125 {
126 	isa_intr_info_t	*iinfo_p;
127 	int		s;
128 
129 	iinfo_p = &milan_isa_iinfo[vector];
130 
131 	s = splx(iinfo_p->ipl);
132 	(void) (iinfo_p->ifunc)(iinfo_p->iarg);
133 	if (vector > 7)
134 		WICU(AD_8259_SLAVE, 0x60 | (vector & 7));
135 	else WICU(AD_8259_MASTER, 0x60 | (vector & 7));
136 	splx(s);
137 }
138 
139 void milan_isa_intr(int, int);
140 void
141 milan_isa_intr(vector, sr)
142 	int	vector, sr;
143 {
144 	isa_intr_info_t *iinfo_p;
145 	int		s;
146 
147 	if (vector >= MILAN_MAX_ISA_INTS) {
148 		printf("milan_isa_intr: Bogus vector %d\n", vector);
149 		return;
150 	}
151 
152 	/* Ack cascade 0x60 == Specific EOI		*/
153 	if (vector > 7)
154 		WICU(AD_8259_MASTER, 0x60|IRQ_SLAVE);
155 
156 	iinfo_p = &milan_isa_iinfo[vector];
157 	if (iinfo_p->ifunc == NULL) {
158 		printf("milan_isa_intr: Stray interrupt: %d (mask:%04x)\n",
159 				vector, imask_enable);
160 		return;
161 	}
162 	if ((sr & PSL_IPL) >= (iinfo_p->ipl & PSL_IPL)) {
163 		/*
164 		 * We're running at a too high priority now.
165 		 */
166 		add_sicallback((si_farg)isa_callback, (void*)vector, 0);
167 	}
168 	else {
169 		s = splx(iinfo_p->ipl);
170 		(void) (iinfo_p->ifunc)(iinfo_p->iarg);
171 		if (vector > 7)
172 			WICU(AD_8259_SLAVE, 0x60 | (vector & 7));
173 		else WICU(AD_8259_MASTER, 0x60 | (vector & 7));
174 		splx(s);
175 	}
176 }
177 
178 /*
179  * Try to allocate a free interrupt... On the Milan, we have available:
180  * 5, 9, 10, 11, 13. Or in a bitmask: 0x1720.
181  */
182 #define	MILAN_AVAIL_ISA_INTS	0x1720
183 
184 int
185 isa_intr_alloc(ic, mask, type, irq)
186 	isa_chipset_tag_t ic;
187 	int mask;
188 	int type;
189 	int *irq;
190 {
191 	int	i;
192 
193 	/*
194 	 * Say no to impossible questions...
195 	 */
196 	if (!(mask &= MILAN_AVAIL_ISA_INTS))
197 		return 1;
198 
199 	for (i = 0; i < MILAN_MAX_ISA_INTS; i++) {
200 		if (mask & (1<<i)) {
201 		    if (milan_isa_iinfo[i].ifunc == NULL) {
202 			*irq = i;
203 			return 0;
204 		    }
205 		}
206 	}
207 	return (1);
208 }
209 
210 void *
211 isa_intr_establish(ic, irq, type, level, ih_fun, ih_arg)
212 	isa_chipset_tag_t ic;
213 	int		  irq, type, level;
214 	int		  (*ih_fun) __P((void *));
215 	void		  *ih_arg;
216 {
217 	isa_intr_info_t *iinfo_p;
218 
219 	iinfo_p = &milan_isa_iinfo[irq];
220 
221 	if (iinfo_p->ifunc != NULL) {
222 		printf("isa_intr_establish: interrupt %d was already "
223 			"established\n", irq);
224 		return NULL;
225 	}
226 
227 	iinfo_p->slot  = 0;	/* Unused on Milan */
228 	iinfo_p->ihand = NULL;	/* Unused on Milan */
229 	iinfo_p->ipl   = level;
230 	iinfo_p->ifunc = ih_fun;
231 	iinfo_p->iarg  = ih_arg;
232 
233 	new_imask();
234 	return(iinfo_p);
235 }
236 
237 void
238 isa_intr_disestablish(ic, handler)
239 	isa_chipset_tag_t	ic;
240 	void			*handler;
241 {
242 	isa_intr_info_t *iinfo_p = (isa_intr_info_t *)handler;
243 
244 	if (iinfo_p->ifunc == NULL)
245 	    panic("isa_intr_disestablish: interrupt was not established");
246 
247 	iinfo_p->ifunc = NULL;
248 	new_imask();
249 }
250