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