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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/powerpc/sysdev/xilinx_intc.c
Initial import
Diffstat (limited to 'arch/powerpc/sysdev/xilinx_intc.c')
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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>
+
+/*
+ * 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_domain *master_irqhost;
+
+#define XILINX_INTC_MAXIRQS (32)
+
+/* The following table allows the interrupt type, edge or level,
+ * to be cached after being read from the device tree until the interrupt
+ * is mapped
+ */
+static int xilinx_intc_typetable[XILINX_INTC_MAXIRQS];
+
+/* Map the interrupt type from the device tree to the interrupt types
+ * used by the interrupt subsystem
+ */
+static unsigned char xilinx_intc_map_senses[] = {
+ IRQ_TYPE_EDGE_RISING,
+ IRQ_TYPE_EDGE_FALLING,
+ IRQ_TYPE_LEVEL_HIGH,
+ IRQ_TYPE_LEVEL_LOW,
+};
+
+/*
+ * The interrupt controller is setup such that it doesn't work well with
+ * the level interrupt handler in the kernel because the handler acks the
+ * interrupt before calling the application interrupt handler. To deal with
+ * that, we use 2 different irq chips so that different functions can be
+ * used for level and edge type interrupts.
+ *
+ * IRQ Chip common (across level and edge) operations
+ */
+static void xilinx_intc_mask(struct irq_data *d)
+{
+ int irq = irqd_to_hwirq(d);
+ void * regs = irq_data_get_irq_chip_data(d);
+ pr_debug("mask: %d\n", irq);
+ out_be32(regs + XINTC_CIE, 1 << irq);
+}
+
+static int xilinx_intc_set_type(struct irq_data *d, unsigned int flow_type)
+{
+ return 0;
+}
+
+/*
+ * IRQ Chip level operations
+ */
+static void xilinx_intc_level_unmask(struct irq_data *d)
+{
+ int irq = irqd_to_hwirq(d);
+ void * regs = irq_data_get_irq_chip_data(d);
+ pr_debug("unmask: %d\n", irq);
+ out_be32(regs + XINTC_SIE, 1 << irq);
+
+ /* ack level irqs because they can't be acked during
+ * ack function since the handle_level_irq function
+ * acks the irq before calling the inerrupt handler
+ */
+ out_be32(regs + XINTC_IAR, 1 << irq);
+}
+
+static struct irq_chip xilinx_intc_level_irqchip = {
+ .name = "Xilinx Level INTC",
+ .irq_mask = xilinx_intc_mask,
+ .irq_mask_ack = xilinx_intc_mask,
+ .irq_unmask = xilinx_intc_level_unmask,
+ .irq_set_type = xilinx_intc_set_type,
+};
+
+/*
+ * IRQ Chip edge operations
+ */
+static void xilinx_intc_edge_unmask(struct irq_data *d)
+{
+ int irq = irqd_to_hwirq(d);
+ void *regs = irq_data_get_irq_chip_data(d);
+ pr_debug("unmask: %d\n", irq);
+ out_be32(regs + XINTC_SIE, 1 << irq);
+}
+
+static void xilinx_intc_edge_ack(struct irq_data *d)
+{
+ int irq = irqd_to_hwirq(d);
+ void * regs = irq_data_get_irq_chip_data(d);
+ pr_debug("ack: %d\n", irq);
+ out_be32(regs + XINTC_IAR, 1 << irq);
+}
+
+static struct irq_chip xilinx_intc_edge_irqchip = {
+ .name = "Xilinx Edge INTC",
+ .irq_mask = xilinx_intc_mask,
+ .irq_unmask = xilinx_intc_edge_unmask,
+ .irq_ack = xilinx_intc_edge_ack,
+ .irq_set_type = xilinx_intc_set_type,
+};
+
+/*
+ * IRQ Host operations
+ */
+
+/**
+ * xilinx_intc_xlate - translate virq# from device tree interrupts property
+ */
+static int xilinx_intc_xlate(struct irq_domain *h, struct device_node *ct,
+ const u32 *intspec, unsigned int intsize,
+ irq_hw_number_t *out_hwirq,
+ unsigned int *out_flags)
+{
+ if ((intsize < 2) || (intspec[0] >= XILINX_INTC_MAXIRQS))
+ return -EINVAL;
+
+ /* keep a copy of the interrupt type til the interrupt is mapped
+ */
+ xilinx_intc_typetable[intspec[0]] = xilinx_intc_map_senses[intspec[1]];
+
+ /* Xilinx uses 2 interrupt entries, the 1st being the h/w
+ * interrupt number, the 2nd being the interrupt type, edge or level
+ */
+ *out_hwirq = intspec[0];
+ *out_flags = xilinx_intc_map_senses[intspec[1]];
+
+ return 0;
+}
+static int xilinx_intc_map(struct irq_domain *h, unsigned int virq,
+ irq_hw_number_t irq)
+{
+ irq_set_chip_data(virq, h->host_data);
+
+ if (xilinx_intc_typetable[irq] == IRQ_TYPE_LEVEL_HIGH ||
+ xilinx_intc_typetable[irq] == IRQ_TYPE_LEVEL_LOW) {
+ irq_set_chip_and_handler(virq, &xilinx_intc_level_irqchip,
+ handle_level_irq);
+ } else {
+ irq_set_chip_and_handler(virq, &xilinx_intc_edge_irqchip,
+ handle_edge_irq);
+ }
+ return 0;
+}
+
+static struct irq_domain_ops xilinx_intc_ops = {
+ .map = xilinx_intc_map,
+ .xlate = xilinx_intc_xlate,
+};
+
+struct irq_domain * __init
+xilinx_intc_init(struct device_node *np)
+{
+ struct irq_domain * irq;
+ void * regs;
+
+ /* Find and map the intc registers */
+ regs = of_iomap(np, 0);
+ if (!regs) {
+ pr_err("xilinx_intc: could not map registers\n");
+ return NULL;
+ }
+
+ /* 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_domain structure. */
+ irq = irq_domain_add_linear(np, XILINX_INTC_MAXIRQS, &xilinx_intc_ops,
+ regs);
+ if (!irq)
+ panic(__FILE__ ": Cannot allocate IRQ host\n");
+
+ 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));
+}
+
+#if defined(CONFIG_PPC_I8259)
+/*
+ * Support code for cascading to 8259 interrupt controllers
+ */
+static void xilinx_i8259_cascade(unsigned int irq, 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) */
+
+static const struct of_device_id xilinx_intc_match[] __initconst = {
+ { .compatible = "xlnx,opb-intc-1.00.c", },
+ { .compatible = "xlnx,xps-intc-1.00.a", },
+ {}
+};
+
+/*
+ * Initialize master Xilinx interrupt controller
+ */
+void __init xilinx_intc_init_tree(void)
+{
+ struct device_node *np;
+
+ /* find top level interrupt controller */
+ for_each_matching_node(np, xilinx_intc_match) {
+ if (!of_get_property(np, "interrupts", NULL))
+ break;
+ }
+ BUG_ON(!np);
+
+ master_irqhost = xilinx_intc_init(np);
+ BUG_ON(!master_irqhost);
+
+ irq_set_default_host(master_irqhost);
+ of_node_put(np);
+
+ xilinx_i8259_setup_cascade();
+}