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
  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;
  77         u8 dma1, dma2;
  78
  79         eisa_irq = inb(EIU_INTRPT_ACK);
  80         dma1 = inb(EISA_DMA1_STATUS);
  81         dma2 = inb(EISA_DMA2_STATUS);
  82
  83         if (eisa_irq < EISA_MAX_IRQ) {
  84                 do_IRQ(eisa_irq);
  85                 return IRQ_HANDLED;
  86         }
  87
  88         /* Oops, Bad Stuff Happened... */
  89         printk(KERN_ERR "eisa_irq %d out of bound\n", eisa_irq);
  90
  91         outb(0x20, EISA_INT2_CTRL);
  92         outb(0x20, EISA_INT1_CTRL);
  93
  94         return IRQ_NONE;
  95 }
  96
  97 static struct irqaction eisa_action = {
  98         .handler        = ip22_eisa_intr,
  99         .name           = "EISA",
 100 };
 101
 102 int __init ip22_eisa_init(void)
 103 {
 104         int i, c;
 105         char *str;
 106
 107         if (!(sgimc->systemid & SGIMC_SYSID_EPRESENT)) {
 108                 printk(KERN_INFO "EISA: bus not present.\n");
 109                 return 1;
 110         }
 111
 112         printk(KERN_INFO "EISA: Probing bus...\n");
 113         for (c = 0, i = 1; i <= IP22_EISA_MAX_SLOTS; i++) {
 114                 if ((str = decode_eisa_sig(0x1000 * i + EISA_VENDOR_ID_OFFSET))) {
 115                         printk(KERN_INFO "EISA: slot %d : %s detected.\n",
 116                                i, str);
 117                         c++;
 118                 }
 119         }
 120         printk(KERN_INFO "EISA: Detected %d card%s.\n", c, c < 2 ? "" : "s");
 121 #ifdef CONFIG_ISA
 122         printk(KERN_INFO "ISA support compiled in.\n");
 123 #endif
 124
 125         /* Warning : BlackMagicAhead(tm).
 126            Please wave your favorite dead chicken over the busses */
 127
 128         /* First say hello to the EIU */
 129         outl(0x0000FFFF, EIU_PREMPT_REG);
 130         outl(1, EIU_QUIET_REG);
 131         outl(0x40f3c07F, EIU_MODE_REG);
 132
 133         /* Now be nice to the EISA chipset */
 134         outb(1, EISA_EXT_NMI_RESET_CTRL);
 135         udelay(50);     /* Wait long enough for the dust to settle */
 136         outb(0, EISA_EXT_NMI_RESET_CTRL);
 137         outb(0, EISA_DMA2_WRITE_SINGLE);
 138
 139         init_i8259_irqs();
 140
 141         /* Cannot use request_irq because of kmalloc not being ready at such
 142          * an early stage. Yes, I've been bitten... */
 143         setup_irq(SGI_EISA_IRQ, &eisa_action);
 144
 145         EISA_bus = 1;
 146         return 0;
 147 }