summaryrefslogtreecommitdiffstats
path: root/arch/mips/sgi-ip22/ip22-eisa.c
blob: da44ccb208299ab73e6774601c2a183e011dc4fa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
/*
 * Basic EISA bus support for the SGI Indigo-2.
 *
 * (C) 2002 Pascal Dameme <netinet@freesurf.fr>
 *      and Marc Zyngier <mzyngier@freesurf.fr>
 *
 * This code is released under both the GPL version 2 and BSD
 * licenses.  Either license may be used.
 *
 * This code offers a very basic support for this EISA bus present in
 * the SGI Indigo-2. It currently only supports PIO (forget about DMA
 * for the time being). This is enough for a low-end ethernet card,
 * but forget about your favorite SCSI card...
 *
 * TODO :
 * - Fix bugs...
 * - Add ISA support
 * - Add DMA (yeah, right...).
 * - Fix more bugs.
 */

#include <linux/eisa.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/mipsregs.h>
#include <asm/addrspace.h>
#include <asm/processor.h>
#include <asm/sgi/ioc.h>
#include <asm/sgi/mc.h>
#include <asm/sgi/ip22.h>
#include <asm/i8259.h>

/* I2 has four EISA slots. */
#define IP22_EISA_MAX_SLOTS	  4
#define EISA_MAX_IRQ             16

#define EIU_MODE_REG     0x0001ffc0
#define EIU_STAT_REG     0x0001ffc4
#define EIU_PREMPT_REG   0x0001ffc8
#define EIU_QUIET_REG    0x0001ffcc
#define EIU_INTRPT_ACK   0x00010004

static char __init *decode_eisa_sig(unsigned long addr)
{
	static char sig_str[EISA_SIG_LEN] __initdata;
	u8 sig[4];
	u16 rev;
	int i;

	for (i = 0; i < 4; i++) {
		sig[i] = inb(addr + i);

		if (!i && (sig[0] & 0x80))
			return NULL;
	}

	sig_str[0] = ((sig[0] >> 2) & 0x1f) + ('A' - 1);
	sig_str[1] = (((sig[0] & 3) << 3) | (sig[1] >> 5)) + ('A' - 1);
	sig_str[2] = (sig[1] & 0x1f) + ('A' - 1);
	rev = (sig[2] << 8) | sig[3];
	sprintf(sig_str + 3, "%04X", rev);

	return sig_str;
}

static irqreturn_t ip22_eisa_intr(int irq, void *dev_id)
{
	u8 eisa_irq;
	u8 dma1, dma2;

	eisa_irq = inb(EIU_INTRPT_ACK);
	dma1 = inb(EISA_DMA1_STATUS);
	dma2 = inb(EISA_DMA2_STATUS);

	if (eisa_irq < EISA_MAX_IRQ) {
		do_IRQ(eisa_irq);
		return IRQ_HANDLED;
	}

	/* Oops, Bad Stuff Happened... */
	printk(KERN_ERR "eisa_irq %d out of bound\n", eisa_irq);

	outb(0x20, EISA_INT2_CTRL);
	outb(0x20, EISA_INT1_CTRL);

	return IRQ_NONE;
}

static struct irqaction eisa_action = {
	.handler	= ip22_eisa_intr,
	.name		= "EISA",
};

int __init ip22_eisa_init(void)
{
	int i, c;
	char *str;

	if (!(sgimc->systemid & SGIMC_SYSID_EPRESENT)) {
		printk(KERN_INFO "EISA: bus not present.\n");
		return 1;
	}

	printk(KERN_INFO "EISA: Probing bus...\n");
	for (c = 0, i = 1; i <= IP22_EISA_MAX_SLOTS; i++) {
		if ((str = decode_eisa_sig(0x1000 * i + EISA_VENDOR_ID_OFFSET))) {
			printk(KERN_INFO "EISA: slot %d : %s detected.\n",
			       i, str);
			c++;
		}
	}
	printk(KERN_INFO "EISA: Detected %d card%s.\n", c, c < 2 ? "" : "s");
#ifdef CONFIG_ISA
	printk(KERN_INFO "ISA support compiled in.\n");
#endif

	/* Warning : BlackMagicAhead(tm).
	   Please wave your favorite dead chicken over the busses */

	/* First say hello to the EIU */
	outl(0x0000FFFF, EIU_PREMPT_REG);
	outl(1, EIU_QUIET_REG);
	outl(0x40f3c07F, EIU_MODE_REG);

	/* Now be nice to the EISA chipset */
	outb(1, EISA_EXT_NMI_RESET_CTRL);
	udelay(50);	/* Wait long enough for the dust to settle */
	outb(0, EISA_EXT_NMI_RESET_CTRL);
	outb(0, EISA_DMA2_WRITE_SINGLE);

	init_i8259_irqs();

	/* Cannot use request_irq because of kmalloc not being ready at such
	 * an early stage. Yes, I've been bitten... */
	setup_irq(SGI_EISA_IRQ, &eisa_action);

	EISA_bus = 1;
	return 0;
}
OpenPOWER on IntegriCloud