patch-2.4.6 linux/arch/sh/stboards/irq.c

• Lines: 150
• Date: Wed Jun 27 13:55:29 2001
• Orig file: v2.4.5/linux/arch/sh/stboards/irq.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.5/linux/arch/sh/stboards/irq.c linux/arch/sh/stboards/irq.c
@@ -0,0 +1,149 @@
+/* 
+ * Copyright (C) 2000 David J. Mckay (david.mckay@st.com)
+ *
+ * May be copied or modified under the terms of the GNU General Public
+ * License.  See linux/COPYING for more information.                            
+ *
+ * Looks after interrupts on the HARP board.
+ *
+ * Bases on the IPR irq system
+ */
+
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+
+#include <asm/system.h>
+#include <asm/io.h>
+
+#include "harp.h"
+
+
+#define NUM_EXTERNAL_IRQS 16
+
+// Early versions of the STB1 Overdrive required this nasty frig
+//#define INVERT_INTMASK_WRITES
+
+static void enable_harp_irq(unsigned int irq);
+static void disable_harp_irq(unsigned int irq);
+
+/* shutdown is same as "disable" */
+#define shutdown_harp_irq disable_harp_irq
+
+static void mask_and_ack_harp(unsigned int);
+static void end_harp_irq(unsigned int irq);
+
+static unsigned int startup_harp_irq(unsigned int irq)
+{
+	enable_harp_irq(irq);
+	return 0;		/* never anything pending */
+}
+
+static struct hw_interrupt_type harp_irq_type = {
+	"Harp-IRQ",
+	startup_harp_irq,
+	shutdown_harp_irq,
+	enable_harp_irq,
+	disable_harp_irq,
+	mask_and_ack_harp,
+	end_harp_irq
+};
+
+static void disable_harp_irq(unsigned int irq)
+{
+	unsigned val, flags;
+	unsigned maskReg;
+	unsigned mask;
+	int pri;
+
+	if (irq < 0 || irq >= NUM_EXTERNAL_IRQS)
+		return;
+
+	pri = 15 - irq;
+
+	if (pri < 8) {
+		maskReg = EPLD_INTMASK0;
+	} else {
+		maskReg = EPLD_INTMASK1;
+		pri -= 8;
+	}
+
+	save_and_cli(flags);
+	mask = ctrl_inl(maskReg);
+	mask &= (~(1 << pri));
+#if defined(INVERT_INTMASK_WRITES)
+	mask ^= 0xff;
+#endif
+	ctrl_outl(mask, maskReg);
+	restore_flags(flags);
+}
+
+static void enable_harp_irq(unsigned int irq)
+{
+	unsigned flags;
+	unsigned maskReg;
+	unsigned mask;
+	int pri;
+
+	if (irq < 0 || irq >= NUM_EXTERNAL_IRQS)
+		return;
+
+	pri = 15 - irq;
+
+	if (pri < 8) {
+		maskReg = EPLD_INTMASK0;
+	} else {
+		maskReg = EPLD_INTMASK1;
+		pri -= 8;
+	}
+
+	save_and_cli(flags);
+	mask = ctrl_inl(maskReg);
+
+
+	mask |= (1 << pri);
+
+#if defined(INVERT_INTMASK_WRITES)
+	mask ^= 0xff;
+#endif
+	ctrl_outl(mask, maskReg);
+
+	restore_flags(flags);
+}
+
+/* This functions sets the desired irq handler to be an overdrive type */
+static void __init make_harp_irq(unsigned int irq)
+{
+	disable_irq_nosync(irq);
+	irq_desc[irq].handler = &harp_irq_type;
+	disable_harp_irq(irq);
+}
+
+static void mask_and_ack_harp(unsigned int irq)
+{
+	disable_harp_irq(irq);
+}
+
+static void end_harp_irq(unsigned int irq)
+{
+	enable_harp_irq(irq);
+}
+
+void __init init_harp_irq(void)
+{
+	int i;
+
+#if !defined(INVERT_INTMASK_WRITES)
+	// On the harp these are set to enable an interrupt
+	ctrl_outl(0x00, EPLD_INTMASK0);
+	ctrl_outl(0x00, EPLD_INTMASK1);
+#else
+	// On the Overdrive the data is inverted before being stored in the reg
+	ctrl_outl(0xff, EPLD_INTMASK0);
+	ctrl_outl(0xff, EPLD_INTMASK1);
+#endif
+
+	for (i = 0; i < NUM_EXTERNAL_IRQS; i++) {
+		make_harp_irq(i);
+	}
+}