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isa_milan.c revision 1.11
      1 /*	$NetBSD: isa_milan.c,v 1.11 2009/03/14 15:36:03 dsl 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 1.11 2009/03/14 15:36:03 dsl 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()
     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()
    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(vector, sr)
    134 	int	vector, sr;
    135 {
    136 	isa_intr_info_t *iinfo_p;
    137 	int		s;
    138 
    139 	if (vector >= MILAN_MAX_ISA_INTS) {
    140 		printf("milan_isa_intr: Bogus vector %d\n", vector);
    141 		return;
    142 	}
    143 
    144 	/* Ack cascade 0x60 == Specific EOI		*/
    145 	if (vector > 7)
    146 		WICU(AD_8259_MASTER, 0x60|IRQ_SLAVE);
    147 
    148 	iinfo_p = &milan_isa_iinfo[vector];
    149 	if (iinfo_p->ifunc == NULL) {
    150 		printf("milan_isa_intr: Stray interrupt: %d (mask:%04x)\n",
    151 				vector, imask_enable);
    152 		return;
    153 	}
    154 	if ((sr & PSL_IPL) >= (iinfo_p->ipl & PSL_IPL)) {
    155 		/*
    156 		 * We're running at a too high priority now.
    157 		 */
    158 		add_sicallback((si_farg)isa_callback, (void*)vector, 0);
    159 	}
    160 	else {
    161 		s = splx(iinfo_p->ipl);
    162 		(void) (iinfo_p->ifunc)(iinfo_p->iarg);
    163 		if (vector > 7)
    164 			WICU(AD_8259_SLAVE, 0x60 | (vector & 7));
    165 		else WICU(AD_8259_MASTER, 0x60 | (vector & 7));
    166 		splx(s);
    167 	}
    168 }
    169 
    170 /*
    171  * Try to allocate a free interrupt... On the Milan, we have available:
    172  * 5, 9, 10, 11, 13. Or in a bitmask: 0x1720.
    173  */
    174 #define	MILAN_AVAIL_ISA_INTS	0x1720
    175 
    176 int
    177 isa_intr_alloc(isa_chipset_tag_t ic, int mask, int type, int *irq)
    178 {
    179 	int	i;
    180 
    181 	/*
    182 	 * Say no to impossible questions...
    183 	 */
    184 	if (!(mask &= MILAN_AVAIL_ISA_INTS))
    185 		return 1;
    186 
    187 	for (i = 0; i < MILAN_MAX_ISA_INTS; i++) {
    188 		if (mask & (1<<i)) {
    189 		    if (milan_isa_iinfo[i].ifunc == NULL) {
    190 			*irq = i;
    191 			return 0;
    192 		    }
    193 		}
    194 	}
    195 	return (1);
    196 }
    197 
    198 void *
    199 isa_intr_establish(ic, irq, type, level, ih_fun, ih_arg)
    200 	isa_chipset_tag_t ic;
    201 	int		  irq, type, level;
    202 	int		  (*ih_fun)(void *);
    203 	void		  *ih_arg;
    204 {
    205 	isa_intr_info_t *iinfo_p;
    206 
    207 	iinfo_p = &milan_isa_iinfo[irq];
    208 
    209 	if (iinfo_p->ifunc != NULL) {
    210 		printf("isa_intr_establish: interrupt %d was already "
    211 			"established\n", irq);
    212 		return NULL;
    213 	}
    214 
    215 	iinfo_p->slot  = 0;	/* Unused on Milan */
    216 	iinfo_p->ihand = NULL;	/* Unused on Milan */
    217 	iinfo_p->ipl   = level;
    218 	iinfo_p->ifunc = ih_fun;
    219 	iinfo_p->iarg  = ih_arg;
    220 
    221 	new_imask();
    222 	return(iinfo_p);
    223 }
    224 
    225 void
    226 isa_intr_disestablish(isa_chipset_tag_t ic, void *handler)
    227 {
    228 	isa_intr_info_t *iinfo_p = (isa_intr_info_t *)handler;
    229 
    230 	if (iinfo_p->ifunc == NULL)
    231 	    panic("isa_intr_disestablish: interrupt was not established");
    232 
    233 	iinfo_p->ifunc = NULL;
    234 	new_imask();
    235 }
    236