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; 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 97static struct irqaction eisa_action = { 98 .handler = ip22_eisa_intr, 99 .name = "EISA", 100}; 101 102int __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} 148