From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 20:49:45 +0200
Subject: Adding upstream version 6.1.76.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 arch/mips/sgi-ip22/ip22-eisa.c | 139 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 139 insertions(+)
 create mode 100644 arch/mips/sgi-ip22/ip22-eisa.c

(limited to 'arch/mips/sgi-ip22/ip22-eisa.c')

diff --git a/arch/mips/sgi-ip22/ip22-eisa.c b/arch/mips/sgi-ip22/ip22-eisa.c
new file mode 100644
index 000000000..f3b0e90e0
--- /dev/null
+++ b/arch/mips/sgi-ip22/ip22-eisa.c
@@ -0,0 +1,139 @@
+/*
+ * 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;
+}
+
+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();
+
+	if (request_irq(SGI_EISA_IRQ, ip22_eisa_intr, 0, "EISA", NULL))
+		pr_err("Failed to request irq %d (EISA)\n", SGI_EISA_IRQ);
+
+	EISA_bus = 1;
+	return 0;
+}
-- 
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