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-rw-r--r--arch/mips/momentum/ocelot_c/cpci-irq.c153
1 files changed, 153 insertions, 0 deletions
diff --git a/arch/mips/momentum/ocelot_c/cpci-irq.c b/arch/mips/momentum/ocelot_c/cpci-irq.c
new file mode 100644
index 0000000..dea48b3
--- /dev/null
+++ b/arch/mips/momentum/ocelot_c/cpci-irq.c
@@ -0,0 +1,153 @@
+/*
+ * Copyright 2002 Momentum Computer
+ * Author: mdharm@momenco.com
+ *
+ * arch/mips/momentum/ocelot_c/cpci-irq.c
+ * Interrupt routines for cpci. Interrupt numbers are assigned from
+ * CPCI_IRQ_BASE to CPCI_IRQ_BASE+8 (8 interrupt sources).
+ *
+ * Note that the high-level software will need to be careful about using
+ * these interrupts. If this board is asserting a cPCI interrupt, it will
+ * also see the asserted interrupt. Care must be taken to avoid an
+ * interrupt flood.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <asm/ptrace.h>
+#include <linux/sched.h>
+#include <linux/kernel_stat.h>
+#include <asm/io.h>
+#include "ocelot_c_fpga.h"
+
+#define CPCI_IRQ_BASE 8
+
+static inline int ls1bit8(unsigned int x)
+{
+ int b = 7, s;
+
+ s = 4; if (((unsigned char)(x << 4)) == 0) s = 0; b -= s; x <<= s;
+ s = 2; if (((unsigned char)(x << 2)) == 0) s = 0; b -= s; x <<= s;
+ s = 1; if (((unsigned char)(x << 1)) == 0) s = 0; b -= s;
+
+ return b;
+}
+
+/* mask off an interrupt -- 0 is enable, 1 is disable */
+static inline void mask_cpci_irq(unsigned int irq)
+{
+ uint32_t value;
+
+ value = OCELOT_FPGA_READ(INTMASK);
+ value |= 1 << (irq - CPCI_IRQ_BASE);
+ OCELOT_FPGA_WRITE(value, INTMASK);
+
+ /* read the value back to assure that it's really been written */
+ value = OCELOT_FPGA_READ(INTMASK);
+}
+
+/* unmask an interrupt -- 0 is enable, 1 is disable */
+static inline void unmask_cpci_irq(unsigned int irq)
+{
+ uint32_t value;
+
+ value = OCELOT_FPGA_READ(INTMASK);
+ value &= ~(1 << (irq - CPCI_IRQ_BASE));
+ OCELOT_FPGA_WRITE(value, INTMASK);
+
+ /* read the value back to assure that it's really been written */
+ value = OCELOT_FPGA_READ(INTMASK);
+}
+
+/*
+ * Enables the IRQ in the FPGA
+ */
+static void enable_cpci_irq(unsigned int irq)
+{
+ unmask_cpci_irq(irq);
+}
+
+/*
+ * Initialize the IRQ in the FPGA
+ */
+static unsigned int startup_cpci_irq(unsigned int irq)
+{
+ unmask_cpci_irq(irq);
+ return 0;
+}
+
+/*
+ * Disables the IRQ in the FPGA
+ */
+static void disable_cpci_irq(unsigned int irq)
+{
+ mask_cpci_irq(irq);
+}
+
+/*
+ * Masks and ACKs an IRQ
+ */
+static void mask_and_ack_cpci_irq(unsigned int irq)
+{
+ mask_cpci_irq(irq);
+}
+
+/*
+ * End IRQ processing
+ */
+static void end_cpci_irq(unsigned int irq)
+{
+ if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+ unmask_cpci_irq(irq);
+}
+
+/*
+ * Interrupt handler for interrupts coming from the FPGA chip.
+ * It could be built in ethernet ports etc...
+ */
+void ll_cpci_irq(struct pt_regs *regs)
+{
+ unsigned int irq_src, irq_mask;
+
+ /* read the interrupt status registers */
+ irq_src = OCELOT_FPGA_READ(INTSTAT);
+ irq_mask = OCELOT_FPGA_READ(INTMASK);
+
+ /* mask for just the interrupts we want */
+ irq_src &= ~irq_mask;
+
+ do_IRQ(ls1bit8(irq_src) + CPCI_IRQ_BASE, regs);
+}
+
+#define shutdown_cpci_irq disable_cpci_irq
+
+struct hw_interrupt_type cpci_irq_type = {
+ "CPCI/FPGA",
+ startup_cpci_irq,
+ shutdown_cpci_irq,
+ enable_cpci_irq,
+ disable_cpci_irq,
+ mask_and_ack_cpci_irq,
+ end_cpci_irq,
+ NULL
+};
+
+void cpci_irq_init(void)
+{
+ int i;
+
+ /* Reset irq handlers pointers to NULL */
+ for (i = CPCI_IRQ_BASE; i < (CPCI_IRQ_BASE + 8); i++) {
+ irq_desc[i].status = IRQ_DISABLED;
+ irq_desc[i].action = 0;
+ irq_desc[i].depth = 2;
+ irq_desc[i].handler = &cpci_irq_type;
+ }
+}
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