1*86d7f5d3SJohn Marino /*-
2*86d7f5d3SJohn Marino * Copyright (c) 2004 John Baldwin <jhb@FreeBSD.org>
3*86d7f5d3SJohn Marino * All rights reserved.
4*86d7f5d3SJohn Marino *
5*86d7f5d3SJohn Marino * Redistribution and use in source and binary forms, with or without
6*86d7f5d3SJohn Marino * modification, are permitted provided that the following conditions
7*86d7f5d3SJohn Marino * are met:
8*86d7f5d3SJohn Marino * 1. Redistributions of source code must retain the above copyright
9*86d7f5d3SJohn Marino * notice, this list of conditions and the following disclaimer.
10*86d7f5d3SJohn Marino * 2. Redistributions in binary form must reproduce the above copyright
11*86d7f5d3SJohn Marino * notice, this list of conditions and the following disclaimer in the
12*86d7f5d3SJohn Marino * documentation and/or other materials provided with the distribution.
13*86d7f5d3SJohn Marino * 3. Neither the name of the author nor the names of any co-contributors
14*86d7f5d3SJohn Marino * may be used to endorse or promote products derived from this software
15*86d7f5d3SJohn Marino * without specific prior written permission.
16*86d7f5d3SJohn Marino *
17*86d7f5d3SJohn Marino * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18*86d7f5d3SJohn Marino * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19*86d7f5d3SJohn Marino * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20*86d7f5d3SJohn Marino * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21*86d7f5d3SJohn Marino * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22*86d7f5d3SJohn Marino * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23*86d7f5d3SJohn Marino * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24*86d7f5d3SJohn Marino * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25*86d7f5d3SJohn Marino * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26*86d7f5d3SJohn Marino * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27*86d7f5d3SJohn Marino * SUCH DAMAGE.
28*86d7f5d3SJohn Marino */
29*86d7f5d3SJohn Marino
30*86d7f5d3SJohn Marino /*
31*86d7f5d3SJohn Marino * The ELCR is a register that controls the trigger mode and polarity of
32*86d7f5d3SJohn Marino * EISA and ISA interrupts. In FreeBSD 3.x and 4.x, the ELCR was only
33*86d7f5d3SJohn Marino * consulted for determining the appropriate trigger mode of EISA
34*86d7f5d3SJohn Marino * interrupts when using an APIC. However, it seems that almost all
35*86d7f5d3SJohn Marino * systems that include PCI also include an ELCR that manages the ISA
36*86d7f5d3SJohn Marino * IRQs 0 through 15. Thus, we check for the presence of an ELCR on
37*86d7f5d3SJohn Marino * every machine by checking to see if the values found at bootup are
38*86d7f5d3SJohn Marino * sane. Note that the polarity of ISA and EISA IRQs are linked to the
39*86d7f5d3SJohn Marino * trigger mode. All edge triggered IRQs use active-hi polarity, and
40*86d7f5d3SJohn Marino * all level triggered interrupts use active-lo polarity.
41*86d7f5d3SJohn Marino *
42*86d7f5d3SJohn Marino * The format of the ELCR is simple: it is a 16-bit bitmap where bit 0
43*86d7f5d3SJohn Marino * controls IRQ 0, bit 1 controls IRQ 1, etc. If the bit is zero, the
44*86d7f5d3SJohn Marino * associated IRQ is edge triggered. If the bit is one, the IRQ is
45*86d7f5d3SJohn Marino * level triggered.
46*86d7f5d3SJohn Marino */
47*86d7f5d3SJohn Marino
48*86d7f5d3SJohn Marino #include <sys/param.h>
49*86d7f5d3SJohn Marino #include <sys/bus.h>
50*86d7f5d3SJohn Marino #include <sys/systm.h>
51*86d7f5d3SJohn Marino #include <sys/kernel.h>
52*86d7f5d3SJohn Marino
53*86d7f5d3SJohn Marino #include <machine_base/icu/elcr_var.h>
54*86d7f5d3SJohn Marino #include <machine_base/isa/isa_intr.h>
55*86d7f5d3SJohn Marino
56*86d7f5d3SJohn Marino #define ELCR_PORT 0x4d0
57*86d7f5d3SJohn Marino #define ELCR_MASK(irq) (1 << (irq))
58*86d7f5d3SJohn Marino
59*86d7f5d3SJohn Marino int elcr_found;
60*86d7f5d3SJohn Marino static int elcr_status;
61*86d7f5d3SJohn Marino
62*86d7f5d3SJohn Marino /*
63*86d7f5d3SJohn Marino * Check to see if we have what looks like a valid ELCR. We do this by
64*86d7f5d3SJohn Marino * verifying that IRQs 0, 1, 2, and 13 are all edge triggered.
65*86d7f5d3SJohn Marino */
66*86d7f5d3SJohn Marino void
elcr_probe(void)67*86d7f5d3SJohn Marino elcr_probe(void)
68*86d7f5d3SJohn Marino {
69*86d7f5d3SJohn Marino int disable = 0;
70*86d7f5d3SJohn Marino
71*86d7f5d3SJohn Marino TUNABLE_INT_FETCH("hw.elcr_disable", &disable);
72*86d7f5d3SJohn Marino if (disable)
73*86d7f5d3SJohn Marino return;
74*86d7f5d3SJohn Marino
75*86d7f5d3SJohn Marino elcr_status = inb(ELCR_PORT) | inb(ELCR_PORT + 1) << 8;
76*86d7f5d3SJohn Marino if ((elcr_status & (ELCR_MASK(0) | ELCR_MASK(1) | ELCR_MASK(2) |
77*86d7f5d3SJohn Marino ELCR_MASK(8) | ELCR_MASK(13))) != 0)
78*86d7f5d3SJohn Marino return;
79*86d7f5d3SJohn Marino elcr_found = 1;
80*86d7f5d3SJohn Marino }
81*86d7f5d3SJohn Marino
82*86d7f5d3SJohn Marino /*
83*86d7f5d3SJohn Marino * Returns 1 for level trigger, 0 for edge.
84*86d7f5d3SJohn Marino */
85*86d7f5d3SJohn Marino enum intr_trigger
elcr_read_trigger(int irq)86*86d7f5d3SJohn Marino elcr_read_trigger(int irq)
87*86d7f5d3SJohn Marino {
88*86d7f5d3SJohn Marino KASSERT(elcr_found, ("%s: no ELCR was found!", __func__));
89*86d7f5d3SJohn Marino KASSERT(irq < ISA_IRQ_CNT, ("%s: invalid IRQ %u", __func__, irq));
90*86d7f5d3SJohn Marino if (elcr_status & ELCR_MASK(irq))
91*86d7f5d3SJohn Marino return (INTR_TRIGGER_LEVEL);
92*86d7f5d3SJohn Marino else
93*86d7f5d3SJohn Marino return (INTR_TRIGGER_EDGE);
94*86d7f5d3SJohn Marino }
95*86d7f5d3SJohn Marino
96*86d7f5d3SJohn Marino /*
97*86d7f5d3SJohn Marino * Set the trigger mode for a specified IRQ. Mode of 0 means edge triggered,
98*86d7f5d3SJohn Marino * and a mode of 1 means level triggered.
99*86d7f5d3SJohn Marino */
100*86d7f5d3SJohn Marino void
elcr_write_trigger(int irq,enum intr_trigger trigger)101*86d7f5d3SJohn Marino elcr_write_trigger(int irq, enum intr_trigger trigger)
102*86d7f5d3SJohn Marino {
103*86d7f5d3SJohn Marino int new_status;
104*86d7f5d3SJohn Marino
105*86d7f5d3SJohn Marino KASSERT(elcr_found, ("%s: no ELCR was found!", __func__));
106*86d7f5d3SJohn Marino KASSERT(irq < ISA_IRQ_CNT, ("%s: invalid IRQ %u", __func__, irq));
107*86d7f5d3SJohn Marino if (trigger == INTR_TRIGGER_LEVEL)
108*86d7f5d3SJohn Marino new_status = elcr_status | ELCR_MASK(irq);
109*86d7f5d3SJohn Marino else
110*86d7f5d3SJohn Marino new_status = elcr_status & ~ELCR_MASK(irq);
111*86d7f5d3SJohn Marino if (new_status == elcr_status)
112*86d7f5d3SJohn Marino return;
113*86d7f5d3SJohn Marino elcr_status = new_status;
114*86d7f5d3SJohn Marino if (irq >= 8)
115*86d7f5d3SJohn Marino outb(ELCR_PORT + 1, elcr_status >> 8);
116*86d7f5d3SJohn Marino else
117*86d7f5d3SJohn Marino outb(ELCR_PORT, elcr_status & 0xff);
118*86d7f5d3SJohn Marino }
119*86d7f5d3SJohn Marino
120*86d7f5d3SJohn Marino void
elcr_resume(void)121*86d7f5d3SJohn Marino elcr_resume(void)
122*86d7f5d3SJohn Marino {
123*86d7f5d3SJohn Marino KASSERT(elcr_found, ("%s: no ELCR was found!", __func__));
124*86d7f5d3SJohn Marino outb(ELCR_PORT, elcr_status & 0xff);
125*86d7f5d3SJohn Marino outb(ELCR_PORT + 1, elcr_status >> 8);
126*86d7f5d3SJohn Marino }
127*86d7f5d3SJohn Marino
128*86d7f5d3SJohn Marino void
elcr_dump(void)129*86d7f5d3SJohn Marino elcr_dump(void)
130*86d7f5d3SJohn Marino {
131*86d7f5d3SJohn Marino if (!elcr_found)
132*86d7f5d3SJohn Marino return;
133*86d7f5d3SJohn Marino
134*86d7f5d3SJohn Marino if (bootverbose) {
135*86d7f5d3SJohn Marino int i;
136*86d7f5d3SJohn Marino
137*86d7f5d3SJohn Marino kprintf("ELCR Found. ISA IRQs programmed as:\n");
138*86d7f5d3SJohn Marino for (i = 0; i < ISA_IRQ_CNT; i++)
139*86d7f5d3SJohn Marino kprintf(" %2d", i);
140*86d7f5d3SJohn Marino kprintf("\n");
141*86d7f5d3SJohn Marino for (i = 0; i < ISA_IRQ_CNT; i++)
142*86d7f5d3SJohn Marino if (elcr_status & ELCR_MASK(i))
143*86d7f5d3SJohn Marino kprintf(" L");
144*86d7f5d3SJohn Marino else
145*86d7f5d3SJohn Marino kprintf(" E");
146*86d7f5d3SJohn Marino kprintf("\n");
147*86d7f5d3SJohn Marino }
148*86d7f5d3SJohn Marino }
149