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-rw-r--r--arch/sh/boards/harp/irq.c148
1 files changed, 148 insertions, 0 deletions
diff --git a/arch/sh/boards/harp/irq.c b/arch/sh/boards/harp/irq.c
new file mode 100644
index 000000000000..acd58489970f
--- /dev/null
+++ b/arch/sh/boards/harp/irq.c
@@ -0,0 +1,148 @@
+/*
+ * 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 <asm/harp/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;
+ }
+
+ local_irq_save(flags);
+ mask = ctrl_inl(maskReg);
+ mask &= (~(1 << pri));
+#if defined(INVERT_INTMASK_WRITES)
+ mask ^= 0xff;
+#endif
+ ctrl_outl(mask, maskReg);
+ local_irq_restore(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;
+ }
+
+ local_irq_save(flags);
+ mask = ctrl_inl(maskReg);
+
+
+ mask |= (1 << pri);
+
+#if defined(INVERT_INTMASK_WRITES)
+ mask ^= 0xff;
+#endif
+ ctrl_outl(mask, maskReg);
+
+ local_irq_restore(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);
+ }
+}