[POWERPC] Virtex: add xilinx interrupt controller driver

Adds support for the Xilinx opb-intc interrupt controller

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

1 files changed, 151 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/xilinx_intc.c b/arch/powerpc/sysdev/xilinx_intc.c
new file mode 100644
index 000000000000..c2f17cc43dfa
--- /dev/null
+++ b/arch/powerpc/sysdev/xilinx_intc.c
@@ -0,0 +1,151 @@
+/*
+ * 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 <asm/io.h>
+#include <asm/processor.h>
+#include <asm/irq.h>
+
+/*
+ * INTC Registers
+ */
+#define XINTC_ISR       0       /* Interrupt Status */
+#define XINTC_IPR       4       /* Interrupt Pending */
+#define XINTC_IER       8       /* Interrupt Enable */
+#define XINTC_IAR       12      /* Interrupt Acknowledge */
+#define XINTC_SIE       16      /* Set Interrupt Enable bits */
+#define XINTC_CIE       20      /* Clear Interrupt Enable bits */
+#define XINTC_IVR       24      /* Interrupt Vector */
+#define XINTC_MER       28      /* Master Enable */
+
+static struct irq_host *master_irqhost;
+
+/*
+ * IRQ Chip operations
+ */
+static void xilinx_intc_mask(unsigned int virq)
+{
+        int irq = virq_to_hw(virq);
+        void * regs = get_irq_chip_data(virq);
+        pr_debug("mask: %d\n", irq);
+        out_be32(regs + XINTC_CIE, 1 << irq);
+}
+
+static void xilinx_intc_unmask(unsigned int virq)
+{
+        int irq = virq_to_hw(virq);
+        void * regs = get_irq_chip_data(virq);
+        pr_debug("unmask: %d\n", irq);
+        out_be32(regs + XINTC_SIE, 1 << irq);
+}
+
+static void xilinx_intc_ack(unsigned int virq)
+{
+        int irq = virq_to_hw(virq);
+        void * regs = get_irq_chip_data(virq);
+        pr_debug("ack: %d\n", irq);
+        out_be32(regs + XINTC_IAR, 1 << irq);
+}
+
+static struct irq_chip xilinx_intc_irqchip = {
+        .typename = "Xilinx INTC",
+        .mask = xilinx_intc_mask,
+        .unmask = xilinx_intc_unmask,
+        .ack = xilinx_intc_ack,
+};
+
+/*
+ * IRQ Host operations
+ */
+static int xilinx_intc_map(struct irq_host *h, unsigned int virq,
+                                  irq_hw_number_t irq)
+{
+        set_irq_chip_data(virq, h->host_data);
+        set_irq_chip_and_handler(virq, &xilinx_intc_irqchip, handle_level_irq);
+        set_irq_type(virq, IRQ_TYPE_NONE);
+        return 0;
+}
+
+static struct irq_host_ops xilinx_intc_ops = {
+        .map = xilinx_intc_map,
+};
+
+struct irq_host * __init
+xilinx_intc_init(struct device_node *np)
+{
+        struct irq_host * irq;
+        struct resource res;
+        void * regs;
+        int rc;
+
+        /* Find and map the intc registers */
+        rc = of_address_to_resource(np, 0, &res);
+        if (rc) {
+                printk(KERN_ERR __FILE__ ": of_address_to_resource() failed\n");
+                return NULL;
+        }
+        regs = ioremap(res.start, 32);
+
+        printk(KERN_INFO "Xilinx intc at 0x%08X mapped to 0x%p\n",
+                res.start, regs);
+
+        /* Setup interrupt controller */
+        out_be32(regs + XINTC_IER, 0); /* disable all irqs */
+        out_be32(regs + XINTC_IAR, ~(u32) 0); /* Acknowledge pending irqs */
+        out_be32(regs + XINTC_MER, 0x3UL); /* Turn on the Master Enable. */
+
+        /* Allocate and initialize an irq_host structure. */
+        irq = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, 32, &xilinx_intc_ops, -1);
+        if (!irq)
+                panic(__FILE__ ": Cannot allocate IRQ host\n");
+        irq->host_data = regs;
+        return irq;
+}
+
+int xilinx_intc_get_irq(void)
+{
+        void * regs = master_irqhost->host_data;
+        pr_debug("get_irq:\n");
+        return irq_linear_revmap(master_irqhost, in_be32(regs + XINTC_IVR));
+}
+
+void __init xilinx_intc_init_tree(void)
+{
+        struct device_node *np;
+
+        /* find top level interrupt controller */
+        for_each_compatible_node(np, NULL, "xilinx,intc") {
+                if (!of_get_property(np, "interrupts", NULL))
+                        break;
+        }
+
+        /* xilinx interrupt controller needs to be top level */
+        BUG_ON(!np);
+
+        master_irqhost = xilinx_intc_init(np);
+        BUG_ON(!master_irqhost);
+
+        irq_set_default_host(master_irqhost);
+        of_node_put(np);
+}