148 lines
3.5 KiB
C
148 lines
3.5 KiB
C
/*
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* Basic EISA bus support for the SGI Indigo-2.
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*
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* (C) 2002 Pascal Dameme <netinet@freesurf.fr>
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* and Marc Zyngier <mzyngier@freesurf.fr>
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*
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* This code is released under both the GPL version 2 and BSD
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* licenses. Either license may be used.
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*
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* This code offers a very basic support for this EISA bus present in
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* the SGI Indigo-2. It currently only supports PIO (forget about DMA
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* for the time being). This is enough for a low-end ethernet card,
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* but forget about your favorite SCSI card...
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*
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* TODO :
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* - Fix bugs...
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* - Add ISA support
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* - Add DMA (yeah, right...).
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* - Fix more bugs.
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*/
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#include <linux/eisa.h>
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/irq.h>
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#include <linux/kernel_stat.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/interrupt.h>
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#include <linux/delay.h>
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#include <asm/io.h>
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#include <asm/irq.h>
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#include <asm/mipsregs.h>
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#include <asm/addrspace.h>
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#include <asm/processor.h>
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#include <asm/sgi/ioc.h>
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#include <asm/sgi/mc.h>
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#include <asm/sgi/ip22.h>
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#include <asm/i8259.h>
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/* I2 has four EISA slots. */
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#define IP22_EISA_MAX_SLOTS 4
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#define EISA_MAX_IRQ 16
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#define EIU_MODE_REG 0x0001ffc0
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#define EIU_STAT_REG 0x0001ffc4
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#define EIU_PREMPT_REG 0x0001ffc8
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#define EIU_QUIET_REG 0x0001ffcc
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#define EIU_INTRPT_ACK 0x00010004
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static char __init *decode_eisa_sig(unsigned long addr)
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{
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static char sig_str[EISA_SIG_LEN];
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u8 sig[4];
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u16 rev;
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int i;
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for (i = 0; i < 4; i++) {
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sig[i] = inb(addr + i);
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if (!i && (sig[0] & 0x80))
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return NULL;
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}
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sig_str[0] = ((sig[0] >> 2) & 0x1f) + ('A' - 1);
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sig_str[1] = (((sig[0] & 3) << 3) | (sig[1] >> 5)) + ('A' - 1);
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sig_str[2] = (sig[1] & 0x1f) + ('A' - 1);
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rev = (sig[2] << 8) | sig[3];
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sprintf(sig_str + 3, "%04X", rev);
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return sig_str;
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}
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static irqreturn_t ip22_eisa_intr(int irq, void *dev_id)
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{
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u8 eisa_irq;
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u8 dma1, dma2;
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eisa_irq = inb(EIU_INTRPT_ACK);
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dma1 = inb(EISA_DMA1_STATUS);
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dma2 = inb(EISA_DMA2_STATUS);
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if (eisa_irq < EISA_MAX_IRQ) {
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do_IRQ(eisa_irq);
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return IRQ_HANDLED;
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}
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/* Oops, Bad Stuff Happened... */
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printk(KERN_ERR "eisa_irq %d out of bound\n", eisa_irq);
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outb(0x20, EISA_INT2_CTRL);
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outb(0x20, EISA_INT1_CTRL);
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return IRQ_NONE;
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}
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static struct irqaction eisa_action = {
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.handler = ip22_eisa_intr,
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.name = "EISA",
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};
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int __init ip22_eisa_init(void)
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{
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int i, c;
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char *str;
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if (!(sgimc->systemid & SGIMC_SYSID_EPRESENT)) {
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printk(KERN_INFO "EISA: bus not present.\n");
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return 1;
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}
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printk(KERN_INFO "EISA: Probing bus...\n");
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for (c = 0, i = 1; i <= IP22_EISA_MAX_SLOTS; i++) {
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if ((str = decode_eisa_sig(0x1000 * i + EISA_VENDOR_ID_OFFSET))) {
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printk(KERN_INFO "EISA: slot %d : %s detected.\n",
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i, str);
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c++;
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}
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}
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printk(KERN_INFO "EISA: Detected %d card%s.\n", c, c < 2 ? "" : "s");
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#ifdef CONFIG_ISA
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printk(KERN_INFO "ISA support compiled in.\n");
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#endif
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/* Warning : BlackMagicAhead(tm).
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Please wave your favorite dead chicken over the busses */
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/* First say hello to the EIU */
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outl(0x0000FFFF, EIU_PREMPT_REG);
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outl(1, EIU_QUIET_REG);
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outl(0x40f3c07F, EIU_MODE_REG);
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/* Now be nice to the EISA chipset */
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outb(1, EISA_EXT_NMI_RESET_CTRL);
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udelay(50); /* Wait long enough for the dust to settle */
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outb(0, EISA_EXT_NMI_RESET_CTRL);
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outb(0, EISA_DMA2_WRITE_SINGLE);
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init_i8259_irqs();
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/* Cannot use request_irq because of kmalloc not being ready at such
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* an early stage. Yes, I've been bitten... */
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setup_irq(SGI_EISA_IRQ, &eisa_action);
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EISA_bus = 1;
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return 0;
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}
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