[RFC PATCHv4 6/6] irqchip: TI-Nspire irqchip support
Daniel Tang
dt.tangr at gmail.com
Sat May 25 07:08:07 EDT 2013
Add support for the interrupt controller on TI-Nspires.
Signed-off-by: Daniel Tang <dt.tangr at gmail.com>
---
.../interrupt-controller/lsi,zevio-intc.txt | 18 +++
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-zevio.c | 177 +++++++++++++++++++++
3 files changed, 196 insertions(+)
create mode 100644 Documentation/devicetree/bindings/interrupt-controller/lsi,zevio-intc.txt
create mode 100644 drivers/irqchip/irq-zevio.c
diff --git a/Documentation/devicetree/bindings/interrupt-controller/lsi,zevio-intc.txt b/Documentation/devicetree/bindings/interrupt-controller/lsi,zevio-intc.txt
new file mode 100644
index 0000000..aee38e7
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/lsi,zevio-intc.txt
@@ -0,0 +1,18 @@
+TI-NSPIRE interrupt controller
+
+Required properties:
+- compatible: Compatible property value should be "lsi,zevio-intc".
+
+- reg: Physical base address of the controller and length of memory mapped
+ region.
+
+- interrupt-controller : Identifies the node as an interrupt controller
+
+Example:
+
+interrupt-controller {
+ compatible = "lsi,zevio-intc";
+ interrupt-controller;
+ reg = <0xDC000000 0x1000>;
+ #interrupt-cells = <1>;
+};
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index cda4cb5..f313d14 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -15,4 +15,5 @@ obj-$(CONFIG_SIRF_IRQ) += irq-sirfsoc.o
obj-$(CONFIG_RENESAS_INTC_IRQPIN) += irq-renesas-intc-irqpin.o
obj-$(CONFIG_RENESAS_IRQC) += irq-renesas-irqc.o
obj-$(CONFIG_VERSATILE_FPGA_IRQ) += irq-versatile-fpga.o
+obj-$(CONFIG_ARCH_NSPIRE) += irq-zevio.o
obj-$(CONFIG_ARCH_VT8500) += irq-vt8500.o
diff --git a/drivers/irqchip/irq-zevio.c b/drivers/irqchip/irq-zevio.c
new file mode 100644
index 0000000..3101c2a
--- /dev/null
+++ b/drivers/irqchip/irq-zevio.c
@@ -0,0 +1,177 @@
+/*
+ * linux/drivers/irqchip/irq-nspire-classic.c
+ *
+ * Copyright (C) 2013 Daniel Tang <tangrs at tangrs.id.au>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#include <asm/mach/irq.h>
+#include <asm/exception.h>
+
+#include "irqchip.h"
+
+#define IO_STATUS 0x000
+#define IO_RAW_STATUS 0x004
+#define IO_ENABLE 0x008
+#define IO_DISABLE 0x00C
+#define IO_CURRENT 0x020
+#define IO_RESET 0x028
+#define IO_MAX_PRIOTY 0x02C
+
+#define IO_IRQ_BASE 0x000
+#define IO_FIQ_BASE 0x100
+
+#define IO_INVERT_SEL 0x200
+#define IO_STICKY_SEL 0x204
+#define IO_PRIORITY_SEL 0x300
+
+#define MAX_INTRS 32
+#define FIQ_START MAX_INTRS
+
+
+static void __iomem *irq_io_base;
+static struct irq_domain *nspire_irq_domain;
+
+static void nspire_irq_ack(struct irq_data *irqd)
+{
+ void __iomem *base = irq_io_base;
+
+ if (irqd->hwirq < FIQ_START)
+ base += IO_IRQ_BASE;
+ else
+ base += IO_FIQ_BASE;
+
+ readl(base + IO_RESET);
+}
+
+static void nspire_irq_unmask(struct irq_data *irqd)
+{
+ void __iomem *base = irq_io_base;
+ int irqnr = irqd->hwirq;
+
+ if (irqnr < FIQ_START) {
+ base += IO_IRQ_BASE;
+ } else {
+ irqnr -= MAX_INTRS;
+ base += IO_FIQ_BASE;
+ }
+
+ writel((1<<irqnr), base + IO_ENABLE);
+}
+
+static void nspire_irq_mask(struct irq_data *irqd)
+{
+ void __iomem *base = irq_io_base;
+ int irqnr = irqd->hwirq;
+
+ if (irqnr < FIQ_START) {
+ base += IO_IRQ_BASE;
+ } else {
+ irqnr -= FIQ_START;
+ base += IO_FIQ_BASE;
+ }
+
+ writel((1<<irqnr), base + IO_DISABLE);
+}
+
+static struct irq_chip nspire_irq_chip = {
+ .name = "nspire_irq",
+ .irq_ack = nspire_irq_ack,
+ .irq_mask = nspire_irq_mask,
+ .irq_unmask = nspire_irq_unmask,
+};
+
+
+static int nspire_irq_map(struct irq_domain *dom, unsigned int virq,
+ irq_hw_number_t hw)
+{
+ irq_set_chip_and_handler(virq, &nspire_irq_chip, handle_level_irq);
+ set_irq_flags(virq, IRQF_VALID | IRQF_PROBE);
+
+ return 0;
+}
+
+static struct irq_domain_ops nspire_irq_ops = {
+ .map = nspire_irq_map,
+ .xlate = irq_domain_xlate_onecell,
+};
+
+static void init_base(void __iomem *base)
+{
+ /* Disable all interrupts */
+ writel(~0, base + IO_DISABLE);
+
+ /* Accept interrupts of all priorities */
+ writel(0xF, base + IO_MAX_PRIOTY);
+
+ /* Reset existing interrupts */
+ readl(base + IO_RESET);
+}
+
+static int process_base(void __iomem *base, struct pt_regs *regs)
+{
+ int irqnr;
+
+
+ if (!readl(base + IO_STATUS))
+ return 0;
+
+ irqnr = readl(base + IO_CURRENT);
+ irqnr = irq_find_mapping(nspire_irq_domain, irqnr);
+ handle_IRQ(irqnr, regs);
+
+ return 1;
+}
+
+asmlinkage void __exception_irq_entry nspire_handle_irq(struct pt_regs *regs)
+{
+ while (process_base(irq_io_base + IO_FIQ_BASE, regs))
+ ;
+ while (process_base(irq_io_base + IO_IRQ_BASE, regs))
+ ;
+}
+
+static int __init nspire_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ if (WARN_ON(irq_io_base))
+ return -EBUSY;
+
+ irq_io_base = of_iomap(node, 0);
+ BUG_ON(!irq_io_base);
+
+ /* Do not invert interrupt status bits */
+ writel(~0, irq_io_base + IO_INVERT_SEL);
+
+ /* Disable sticky interrupts */
+ writel(0, irq_io_base + IO_STICKY_SEL);
+
+ /* We don't use IRQ priorities. Set each IRQ to highest priority. */
+ memset_io(irq_io_base + IO_PRIORITY_SEL, 0, MAX_INTRS * sizeof(u32));
+
+ /* Init IRQ and FIQ */
+ init_base(irq_io_base + IO_IRQ_BASE);
+ init_base(irq_io_base + IO_FIQ_BASE);
+
+ nspire_irq_domain = irq_domain_add_linear(node, MAX_INTRS,
+ &nspire_irq_ops, NULL);
+
+ BUG_ON(!nspire_irq_domain);
+
+ set_handle_irq(nspire_handle_irq);
+
+ pr_info("TI-NSPIRE classic IRQ controller\n");
+ return 0;
+}
+
+IRQCHIP_DECLARE(nspire_classic_irq, "lsi,zevio-intc", nspire_of_init);
--
1.8.1.3
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