/*
* Basic EISA bus support for the SGI Indigo-2.
*
* (C) 2002 Pascal Dameme <netinet@freesurf.fr>
* and Marc Zyngier <mzyngier@freesurf.fr>
*
* This code is released under both the GPL version 2 and BSD
* licenses. Either license may be used.
*
* This code offers a very basic support for this EISA bus present in
* the SGI Indigo-2. It currently only supports PIO (forget about DMA
* for the time being). This is enough for a low-end ethernet card,
* but forget about your favorite SCSI card...
*
* TODO :
* - Fix bugs...
* - Add ISA support
* - Add DMA (yeah, right...).
* - Fix more bugs.
*/
#include <linux/eisa.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/mipsregs.h>
#include <asm/addrspace.h>
#include <asm/processor.h>
#include <asm/sgi/ioc.h>
#include <asm/sgi/mc.h>
#include <asm/sgi/ip22.h>
#include <asm/i8259.h>
/* I2 has four EISA slots. */
#define IP22_EISA_MAX_SLOTS 4
#define EISA_MAX_IRQ 16
#define EIU_MODE_REG 0x0001ffc0
#define EIU_STAT_REG 0x0001ffc4
#define EIU_PREMPT_REG 0x0001ffc8
#define EIU_QUIET_REG 0x0001ffcc
#define EIU_INTRPT_ACK 0x00010004
static char __init *decode_eisa_sig(unsigned long addr)
{
static char sig_str[EISA_SIG_LEN] __initdata;
u8 sig[4];
u16 rev;
int i;
for (i = 0; i < 4; i++) {
sig[i] = inb(addr + i);
if (!i && (sig[0] & 0x80))
return NULL;
}
sig_str[0] = ((sig[0] >> 2) & 0x1f) + ('A' - 1);
sig_str[1] = (((sig[0] & 3) << 3) | (sig[1] >> 5)) + ('A' - 1);
sig_str[2] = (sig[1] & 0x1f) + ('A' - 1);
rev = (sig[2] << 8) | sig[3];
sprintf(sig_str + 3, "%04X", rev);
return sig_str;
}
static irqreturn_t ip22_eisa_intr(int irq, void *dev_id)
{
u8 eisa_irq = inb(EIU_INTRPT_ACK);
inb(EISA_DMA1_STATUS);
inb(EISA_DMA2_STATUS);
if (eisa_irq < EISA_MAX_IRQ) {
do_IRQ(eisa_irq);
return IRQ_HANDLED;
}
/* Oops, Bad Stuff Happened... */
printk(KERN_ERR "eisa_irq %d out of bound\n", eisa_irq);
outb(0x20, EISA_INT2_CTRL);
outb(0x20, EISA_INT1_CTRL);
return IRQ_NONE;
}
static struct irqaction eisa_action = {
.handler = ip22_eisa_intr,
.name = "EISA",
};
int __init ip22_eisa_init(void)
{
int i, c;
char *str;
if (!(sgimc->systemid & SGIMC_SYSID_EPRESENT)) {
printk(KERN_INFO "EISA: bus not present.\n");
return 1;
}
printk(KERN_INFO "EISA: Probing bus...\n");
for (c = 0, i = 1; i <= IP22_EISA_MAX_SLOTS; i++) {
if ((str = decode_eisa_sig(0x1000 * i + EISA_VENDOR_ID_OFFSET))) {
printk(KERN_INFO "EISA: slot %d : %s detected.\n",
i, str);
c++;
}
}
printk(KERN_INFO "EISA: Detected %d card%s.\n", c, c < 2 ? "" : "s");
#ifdef CONFIG_ISA
printk(KERN_INFO "ISA support compiled in.\n");
#endif
/* Warning : BlackMagicAhead(tm).
Please wave your favorite dead chicken over the busses */
/* First say hello to the EIU */
outl(0x0000FFFF, EIU_PREMPT_REG);
outl(1, EIU_QUIET_REG);
outl(0x40f3c07F, EIU_MODE_REG);
/* Now be nice to the EISA chipset */
outb(1, EISA_EXT_NMI_RESET_CTRL);
udelay(50); /* Wait long enough for the dust to settle */
outb(0, EISA_EXT_NMI_RESET_CTRL);
outb(0, EISA_DMA2_WRITE_SINGLE);
init_i8259_irqs();
/* Cannot use request_irq because of kmalloc not being ready at such
* an early stage. Yes, I've been bitten... */
setup_irq(SGI_EISA_IRQ, &eisa_action);
EISA_bus = 1;
return 0;
}
