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isa_milan.c revision 1.9.8.1
      1 /*	$NetBSD: isa_milan.c,v 1.9.8.1 2009/04/28 07:33:52 skrll 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  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: isa_milan.c,v 1.9.8.1 2009/04/28 07:33:52 skrll Exp $");
     34 
     35 #include <sys/types.h>
     36 #include <sys/param.h>
     37 #include <sys/systm.h>
     38 #include <sys/device.h>
     39 
     40 #include <dev/isa/isavar.h>
     41 #include <dev/isa/isareg.h>
     42 
     43 #include <machine/iomap.h>
     44 
     45 void	isa_bus_init(void);
     46 
     47 static void new_imask(void);
     48 static void isa_callback(int);
     49 
     50 /*
     51  * Bitmask of currently enabled isa interrupts. Used by new_imask().
     52  */
     53 static u_int16_t imask_enable = 0xffff;
     54 
     55 #define	IRQ_SLAVE		2	/* Slave at level 2		*/
     56 #define MILAN_MAX_ISA_INTS	16	/* Max. number of vectors	*/
     57 #define	ICU_OFFSET		0	/* Interrupt vector base	*/
     58 
     59 #define	WICU(icu, val)		*(volatile u_int8_t*)(icu) = val
     60 
     61 static isa_intr_info_t milan_isa_iinfo[MILAN_MAX_ISA_INTS];
     62 
     63 void
     64 isa_bus_init(void)
     65 {
     66 	volatile u_int8_t	*icu;
     67 
     68 	/*
     69 	 * Initialize both the icu's:
     70 	 *   - enter Special Mask Mode
     71 	 *   - Block all interrupts
     72 	 */
     73 	icu = (u_int8_t*)(AD_8259_MASTER);
     74 
     75 	icu[0] = 0x11;			/* reset; program device, four bytes */
     76 	icu[1] = ICU_OFFSET;		/* starting at this vector index */
     77 	icu[1] = (1 << IRQ_SLAVE);	/* slave on line 2 */
     78 	icu[1] = 1;			/* 8086 mode */
     79 	icu[1] = 0xff;			/* leave interrupts masked */
     80 	icu[0] = 0x68;			/* special mask mode  */
     81 	icu[0] = 0x0a;			/* Read IRR by default. */
     82 
     83 	icu = (u_int8_t*)(AD_8259_SLAVE);
     84 
     85 	icu[0] = 0x11;			/* reset; program device, four bytes */
     86 	icu[1] = ICU_OFFSET + 8;	/* starting at this vector index */
     87 	icu[1] = IRQ_SLAVE;		/* slave on line 2 */
     88 	icu[1] = 1;			/* 8086 mode */
     89 	icu[1] = 0xff;			/* leave interrupts masked */
     90 	icu[0] = 0x68;			/* special mask mode  */
     91 	icu[0] = 0x0a;			/* Read IRR by default. */
     92 }
     93 
     94 /*
     95  * Determine and activate new interrupt mask by scanning the milan_isa_iinfo
     96  * array for enabled interrupts.
     97  */
     98 static void
     99 new_imask(void)
    100 {
    101 	int		irq;
    102 	u_int16_t	nmask = 0;
    103 
    104 	for (irq = 0; irq < MILAN_MAX_ISA_INTS; irq++) {
    105 		if (milan_isa_iinfo[irq].ifunc != NULL)
    106 			nmask |= 1 << irq;
    107 		if (nmask >= 0x100)
    108 			nmask |= 1 << IRQ_SLAVE;
    109 	}
    110 	imask_enable = ~nmask;
    111 	WICU(AD_8259_MASTER+1, imask_enable & 0xff);
    112 	WICU(AD_8259_SLAVE+1 , (imask_enable >> 8) & 0xff);
    113 }
    114 
    115 static void
    116 isa_callback(int vector)
    117 {
    118 	isa_intr_info_t	*iinfo_p;
    119 	int		s;
    120 
    121 	iinfo_p = &milan_isa_iinfo[vector];
    122 
    123 	s = splx(iinfo_p->ipl);
    124 	(void) (iinfo_p->ifunc)(iinfo_p->iarg);
    125 	if (vector > 7)
    126 		WICU(AD_8259_SLAVE, 0x60 | (vector & 7));
    127 	else WICU(AD_8259_MASTER, 0x60 | (vector & 7));
    128 	splx(s);
    129 }
    130 
    131 void milan_isa_intr(int, int);
    132 void
    133 milan_isa_intr(int vector, int sr)
    134 {
    135 	isa_intr_info_t *iinfo_p;
    136 	int		s;
    137 
    138 	if (vector >= MILAN_MAX_ISA_INTS) {
    139 		printf("milan_isa_intr: Bogus vector %d\n", vector);
    140 		return;
    141 	}
    142 
    143 	/* Ack cascade 0x60 == Specific EOI		*/
    144 	if (vector > 7)
    145 		WICU(AD_8259_MASTER, 0x60|IRQ_SLAVE);
    146 
    147 	iinfo_p = &milan_isa_iinfo[vector];
    148 	if (iinfo_p->ifunc == NULL) {
    149 		printf("milan_isa_intr: Stray interrupt: %d (mask:%04x)\n",
    150 				vector, imask_enable);
    151 		return;
    152 	}
    153 	if ((sr & PSL_IPL) >= (iinfo_p->ipl & PSL_IPL)) {
    154 		/*
    155 		 * We're running at a too high priority now.
    156 		 */
    157 		add_sicallback((si_farg)isa_callback, (void*)vector, 0);
    158 	}
    159 	else {
    160 		s = splx(iinfo_p->ipl);
    161 		(void) (iinfo_p->ifunc)(iinfo_p->iarg);
    162 		if (vector > 7)
    163 			WICU(AD_8259_SLAVE, 0x60 | (vector & 7));
    164 		else WICU(AD_8259_MASTER, 0x60 | (vector & 7));
    165 		splx(s);
    166 	}
    167 }
    168 
    169 /*
    170  * Try to allocate a free interrupt... On the Milan, we have available:
    171  * 5, 9, 10, 11, 13. Or in a bitmask: 0x1720.
    172  */
    173 #define	MILAN_AVAIL_ISA_INTS	0x1720
    174 
    175 int
    176 isa_intr_alloc(isa_chipset_tag_t ic, int mask, int type, int *irq)
    177 {
    178 	int	i;
    179 
    180 	/*
    181 	 * Say no to impossible questions...
    182 	 */
    183 	if (!(mask &= MILAN_AVAIL_ISA_INTS))
    184 		return 1;
    185 
    186 	for (i = 0; i < MILAN_MAX_ISA_INTS; i++) {
    187 		if (mask & (1<<i)) {
    188 		    if (milan_isa_iinfo[i].ifunc == NULL) {
    189 			*irq = i;
    190 			return 0;
    191 		    }
    192 		}
    193 	}
    194 	return (1);
    195 }
    196 
    197 void *
    198 isa_intr_establish(isa_chipset_tag_t ic, int irq, int type, int level, int (*ih_fun)(void *), void *ih_arg)
    199 {
    200 	isa_intr_info_t *iinfo_p;
    201 
    202 	iinfo_p = &milan_isa_iinfo[irq];
    203 
    204 	if (iinfo_p->ifunc != NULL) {
    205 		printf("isa_intr_establish: interrupt %d was already "
    206 			"established\n", irq);
    207 		return NULL;
    208 	}
    209 
    210 	iinfo_p->slot  = 0;	/* Unused on Milan */
    211 	iinfo_p->ihand = NULL;	/* Unused on Milan */
    212 	iinfo_p->ipl   = level;
    213 	iinfo_p->ifunc = ih_fun;
    214 	iinfo_p->iarg  = ih_arg;
    215 
    216 	new_imask();
    217 	return(iinfo_p);
    218 }
    219 
    220 void
    221 isa_intr_disestablish(isa_chipset_tag_t ic, void *handler)
    222 {
    223 	isa_intr_info_t *iinfo_p = (isa_intr_info_t *)handler;
    224 
    225 	if (iinfo_p->ifunc == NULL)
    226 	    panic("isa_intr_disestablish: interrupt was not established");
    227 
    228 	iinfo_p->ifunc = NULL;
    229 	new_imask();
    230 }
    231