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/arch/mips/sgi-ip22/ip22-eisa.c

http://github.com/mirrors/linux
C | 139 lines | 90 code | 23 blank | 26 comment | 8 complexity | c55cbb8f8792446aa07b2c552b318b4f MD5 | raw file
  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
 51static 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
 74static 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
 95int __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}