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-rw-r--r--arch/powerpc/sysdev/xilinx_intc.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/xilinx_intc.c b/arch/powerpc/sysdev/xilinx_intc.c
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+++ b/arch/powerpc/sysdev/xilinx_intc.c
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+/*
+ * Interrupt controller driver for Xilinx Virtex FPGAs
+ *
+ * Copyright (C) 2007 Secret Lab Technologies Ltd.
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ *
+ */
+
+/*
+ * This is a driver for the interrupt controller typically found in
+ * Xilinx Virtex FPGA designs.
+ *
+ * The interrupt sense levels are hard coded into the FPGA design with
+ * typically a 1:1 relationship between irq lines and devices (no shared
+ * irq lines). Therefore, this driver does not attempt to handle edge
+ * and level interrupts differently.
+ */
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/i8259.h>
+#include <asm/irq.h>
+#include <linux/irqchip.h>
+
+#if defined(CONFIG_PPC_I8259)
+/*
+ * Support code for cascading to 8259 interrupt controllers
+ */
+static void xilinx_i8259_cascade(struct irq_desc *desc)
+{
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ unsigned int cascade_irq = i8259_irq();
+
+ if (cascade_irq)
+ generic_handle_irq(cascade_irq);
+
+ /* Let xilinx_intc end the interrupt */
+ chip->irq_unmask(&desc->irq_data);
+}
+
+static void __init xilinx_i8259_setup_cascade(void)
+{
+ struct device_node *cascade_node;
+ int cascade_irq;
+
+ /* Initialize i8259 controller */
+ cascade_node = of_find_compatible_node(NULL, NULL, "chrp,iic");
+ if (!cascade_node)
+ return;
+
+ cascade_irq = irq_of_parse_and_map(cascade_node, 0);
+ if (!cascade_irq) {
+ pr_err("virtex_ml510: Failed to map cascade interrupt\n");
+ goto out;
+ }
+
+ i8259_init(cascade_node, 0);
+ irq_set_chained_handler(cascade_irq, xilinx_i8259_cascade);
+
+ /* Program irq 7 (usb/audio), 14/15 (ide) to level sensitive */
+ /* This looks like a dirty hack to me --gcl */
+ outb(0xc0, 0x4d0);
+ outb(0xc0, 0x4d1);
+
+ out:
+ of_node_put(cascade_node);
+}
+#else
+static inline void xilinx_i8259_setup_cascade(void) { return; }
+#endif /* defined(CONFIG_PPC_I8259) */
+
+/*
+ * Initialize master Xilinx interrupt controller
+ */
+void __init xilinx_intc_init_tree(void)
+{
+ irqchip_init();
+ xilinx_i8259_setup_cascade();
+}