patch-2.4.19 linux-2.4.19/arch/mips/cobalt/via.c

• Lines: 100
• Date: Fri Aug 2 17:39:43 2002
• Orig file: linux-2.4.18/arch/mips/cobalt/via.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.18/arch/mips/cobalt/via.c linux-2.4.19/arch/mips/cobalt/via.c
@@ -0,0 +1,99 @@
+/*
+ * VIA chipset irq handling
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1996, 1997 by Ralf Baechle
+ * Copyright (C) 2001 by Liam Davies (ldavies@agile.tv)
+ *
+ */
+
+#include <linux/kernel.h>
+#include <asm/cobalt/cobalt.h>
+#include <asm/ptrace.h>
+#include <asm/io.h>
+#include <asm/mipsregs.h>
+
+extern void do_IRQ(int irq, struct pt_regs * regs);
+
+/* Cached values of VIA PIC masks, we start with cascade enabled */
+static unsigned int cached_irq_mask = 0xfffb;
+
+#define __byte(x,y)	(((unsigned char *)&(y))[x])
+#define cached_21	(__byte(0,cached_irq_mask))
+#define cached_A1	(__byte(1,cached_irq_mask))
+
+
+void mask_irq(unsigned int irq)
+{
+	unsigned int mask = 1 << irq;
+
+	cached_irq_mask |= mask;
+	if (irq & 8) {
+		VIA_PORT_WRITE(0xA1, cached_A1);
+	} else {
+		VIA_PORT_WRITE(0x21, cached_21);
+	}
+}
+
+void unmask_irq(unsigned int irq)
+{
+	unsigned int mask = ~(1 << irq);
+
+	cached_irq_mask &= mask;
+	if (irq & 8) {
+		VIA_PORT_WRITE(0xA1, cached_A1);
+	} else {
+		VIA_PORT_WRITE(0x21, cached_21);
+	}
+}
+
+asmlinkage void via_irq(struct pt_regs *regs)
+{
+	char mstat, sstat;
+  
+	/* Read Master Status */
+	VIA_PORT_WRITE(0x20, 0x0C);
+	mstat = VIA_PORT_READ(0x20);
+ 
+	if (mstat < 0) {
+		mstat &= 0x7f;
+		if (mstat != 2) {     	
+			do_IRQ(mstat, regs);
+			VIA_PORT_WRITE(0x20, mstat | 0x20);
+		} else {
+			sstat = VIA_PORT_READ(0xA0);
+
+			/* Slave interrupt */
+			VIA_PORT_WRITE(0xA0, 0x0C);
+			sstat = VIA_PORT_READ(0xA0);
+   
+			if (sstat < 0) {
+				do_IRQ((sstat + 8) & 0x7f, regs);
+				VIA_PORT_WRITE(0x20, 0x22);       
+				VIA_PORT_WRITE(0xA0, (sstat & 0x7f) | 0x20);
+			} else {
+				printk("Spurious slave interrupt...\n");
+			}
+		}
+	} else
+		printk("Spurious master interrupt...");
+}
+
+#define GALILEO_INTCAUSE	0xb4000c18
+#define GALILEO_T0EXP		0x00000100
+
+asmlinkage void galileo_irq(struct pt_regs *regs)
+{
+	unsigned long irq_src = *((unsigned long *) GALILEO_INTCAUSE); 
+
+	/* Check for timer irq ... */
+	if (irq_src & GALILEO_T0EXP) {
+		/* Clear the int line */
+		*((volatile unsigned long *) GALILEO_INTCAUSE) = 0;
+		do_IRQ(0, regs);
+	} else
+		printk("Spurious Galileo interrupt...\n");
+}