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

   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
  95static struct irqaction eisa_action = {
  96        .handler        = ip22_eisa_intr,
  97        .name           = "EISA",
  98};
  99
 100int __init ip22_eisa_init(void)
 101{
 102        int i, c;
 103        char *str;
 104
 105        if (!(sgimc->systemid & SGIMC_SYSID_EPRESENT)) {
 106                printk(KERN_INFO "EISA: bus not present.\n");
 107                return 1;
 108        }
 109
 110        printk(KERN_INFO "EISA: Probing bus...\n");
 111        for (c = 0, i = 1; i <= IP22_EISA_MAX_SLOTS; i++) {
 112                if ((str = decode_eisa_sig(0x1000 * i + EISA_VENDOR_ID_OFFSET))) {
 113                        printk(KERN_INFO "EISA: slot %d : %s detected.\n",
 114                               i, str);
 115                        c++;
 116                }
 117        }
 118        printk(KERN_INFO "EISA: Detected %d card%s.\n", c, c < 2 ? "" : "s");
 119#ifdef CONFIG_ISA
 120        printk(KERN_INFO "ISA support compiled in.\n");
 121#endif
 122
 123        /* Warning : BlackMagicAhead(tm).
 124           Please wave your favorite dead chicken over the busses */
 125
 126        /* First say hello to the EIU */
 127        outl(0x0000FFFF, EIU_PREMPT_REG);
 128        outl(1, EIU_QUIET_REG);
 129        outl(0x40f3c07F, EIU_MODE_REG);
 130
 131        /* Now be nice to the EISA chipset */
 132        outb(1, EISA_EXT_NMI_RESET_CTRL);
 133        udelay(50);     /* Wait long enough for the dust to settle */
 134        outb(0, EISA_EXT_NMI_RESET_CTRL);
 135        outb(0, EISA_DMA2_WRITE_SINGLE);
 136
 137        init_i8259_irqs();
 138
 139        /* Cannot use request_irq because of kmalloc not being ready at such
 140         * an early stage. Yes, I've been bitten... */
 141        setup_irq(SGI_EISA_IRQ, &eisa_action);
 142
 143        EISA_bus = 1;
 144        return 0;
 145}
 146