1 /*
2 * Basic EISA bus support for the SGI Indigo-2.
3 *
4 * (C) 2002 Pascal Dameme <netinet@freesurf.fr>
5 * and Marc Zyngier <mzyngier@freesurf.fr>
6 *
7 * This code is released under both the GPL version 2 and BSD
8 * licenses. Either license may be used.
9 *
10 * This code offers a very basic support for this EISA bus present in
11 * the SGI Indigo-2. It currently only supports PIO (forget about DMA
12 * for the time being). This is enough for a low-end ethernet card,
13 * but forget about your favorite SCSI card...
14 *
15 * TODO :
16 * - Fix bugs...
17 * - Add ISA support
18 * - Add DMA (yeah, right...).
19 * - Fix more bugs.
20 */
21
22 #include <linux/eisa.h>
23 #include <linux/types.h>
24 #include <linux/init.h>
25 #include <linux/irq.h>
26 #include <linux/kernel_stat.h>
27 #include <linux/signal.h>
28 #include <linux/sched.h>
29 #include <linux/interrupt.h>
30 #include <linux/delay.h>
31 #include <asm/io.h>
32 #include <asm/irq.h>
33 #include <asm/mipsregs.h>
34 #include <asm/addrspace.h>
35 #include <asm/processor.h>
36 #include <asm/sgi/ioc.h>
37 #include <asm/sgi/mc.h>
38 #include <asm/sgi/ip22.h>
39 #include <asm/i8259.h>
40
41 /* I2 has four EISA slots. */
42 #define IP22_EISA_MAX_SLOTS 4
43 #define EISA_MAX_IRQ 16
44
45 #define EIU_MODE_REG 0x0001ffc0
46 #define EIU_STAT_REG 0x0001ffc4
47 #define EIU_PREMPT_REG 0x0001ffc8
48 #define EIU_QUIET_REG 0x0001ffcc
49 #define EIU_INTRPT_ACK 0x00010004
50
51 static char __init *decode_eisa_sig(unsigned long addr)
52 {
53 static char sig_str[EISA_SIG_LEN] __initdata;
54 u8 sig[4];
55 u16 rev;
56 int i;
57
58 for (i = 0; i < 4; i++) {
59 sig[i] = inb(addr + i);
60
61 if (!i && (sig[0] & 0x80))
62 return NULL;
63 }
64
65 sig_str[0] = ((sig[0] >> 2) & 0x1f) + ('A' - 1);
66 sig_str[1] = (((sig[0] & 3) << 3) | (sig[1] >> 5)) + ('A' - 1);
67 sig_str[2] = (sig[1] & 0x1f) + ('A' - 1);
68 rev = (sig[2] << 8) | sig[3];
69 sprintf(sig_str + 3, "%04X", rev);
70
71 return sig_str;
72 }
73
74 static irqreturn_t ip22_eisa_intr(int irq, void *dev_id)
75 {
76 u8 eisa_irq = inb(EIU_INTRPT_ACK);
77
78 inb(EISA_DMA1_STATUS);
79 inb(EISA_DMA2_STATUS);
80
81 if (eisa_irq < EISA_MAX_IRQ) {
82 do_IRQ(eisa_irq);
83 return IRQ_HANDLED;
84 }
85
86 /* Oops, Bad Stuff Happened... */
87 printk(KERN_ERR "eisa_irq %d out of bound\n", eisa_irq);
88
89 outb(0x20, EISA_INT2_CTRL);
90 outb(0x20, EISA_INT1_CTRL);
91
92 return IRQ_NONE;
93 }
94
95 int __init ip22_eisa_init(void)
96 {
97 int i, c;
98 char *str;
99
100 if (!(sgimc->systemid & SGIMC_SYSID_EPRESENT)) {
101 printk(KERN_INFO "EISA: bus not present.\n");
102 return 1;
103 }
104
105 printk(KERN_INFO "EISA: Probing bus...\n");
106 for (c = 0, i = 1; i <= IP22_EISA_MAX_SLOTS; i++) {
107 if ((str = decode_eisa_sig(0x1000 * i + EISA_VENDOR_ID_OFFSET))) {
108 printk(KERN_INFO "EISA: slot %d : %s detected.\n",
109 i, str);
110 c++;
111 }
112 }
113 printk(KERN_INFO "EISA: Detected %d card%s.\n", c, c < 2 ? "" : "s");
114 #ifdef CONFIG_ISA
115 printk(KERN_INFO "ISA support compiled in.\n");
116 #endif
117
118 /* Warning : BlackMagicAhead(tm).
119 Please wave your favorite dead chicken over the busses */
120
121 /* First say hello to the EIU */
122 outl(0x0000FFFF, EIU_PREMPT_REG);
123 outl(1, EIU_QUIET_REG);
124 outl(0x40f3c07F, EIU_MODE_REG);
125
126 /* Now be nice to the EISA chipset */
127 outb(1, EISA_EXT_NMI_RESET_CTRL);
128 udelay(50); /* Wait long enough for the dust to settle */
129 outb(0, EISA_EXT_NMI_RESET_CTRL);
130 outb(0, EISA_DMA2_WRITE_SINGLE);
131
132 init_i8259_irqs();
133
134 if (request_irq(SGI_EISA_IRQ, ip22_eisa_intr, 0, "EISA", NULL))
135 pr_err("Failed to request irq %d (EISA)\n", SGI_EISA_IRQ);
136
137 EISA_bus = 1;
138 return 0;
139 }
140
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