v4.19.13 snapshot.
diff --git a/drivers/irqchip/irq-zevio.c b/drivers/irqchip/irq-zevio.c
new file mode 100644
index 0000000..cb9d8ec
--- /dev/null
+++ b/drivers/irqchip/irq-zevio.c
@@ -0,0 +1,124 @@
+/*
+ * linux/drivers/irqchip/irq-zevio.c
+ *
+ * Copyright (C) 2013 Daniel Tang <tangrs@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/irqchip.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#include <asm/mach/irq.h>
+#include <asm/exception.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 struct irq_domain *zevio_irq_domain;
+static void __iomem *zevio_irq_io;
+
+static void zevio_irq_ack(struct irq_data *irqd)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(irqd);
+ struct irq_chip_regs *regs = &irq_data_get_chip_type(irqd)->regs;
+
+ readl(gc->reg_base + regs->ack);
+}
+
+static void __exception_irq_entry zevio_handle_irq(struct pt_regs *regs)
+{
+ int irqnr;
+
+ while (readl(zevio_irq_io + IO_STATUS)) {
+ irqnr = readl(zevio_irq_io + IO_CURRENT);
+ handle_domain_irq(zevio_irq_domain, irqnr, regs);
+ };
+}
+
+static void __init zevio_init_irq_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 __init zevio_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
+ struct irq_chip_generic *gc;
+ int ret;
+
+ if (WARN_ON(zevio_irq_io || zevio_irq_domain))
+ return -EBUSY;
+
+ zevio_irq_io = of_iomap(node, 0);
+ BUG_ON(!zevio_irq_io);
+
+ /* Do not invert interrupt status bits */
+ writel(~0, zevio_irq_io + IO_INVERT_SEL);
+
+ /* Disable sticky interrupts */
+ writel(0, zevio_irq_io + IO_STICKY_SEL);
+
+ /* We don't use IRQ priorities. Set each IRQ to highest priority. */
+ memset_io(zevio_irq_io + IO_PRIORITY_SEL, 0, MAX_INTRS * sizeof(u32));
+
+ /* Init IRQ and FIQ */
+ zevio_init_irq_base(zevio_irq_io + IO_IRQ_BASE);
+ zevio_init_irq_base(zevio_irq_io + IO_FIQ_BASE);
+
+ zevio_irq_domain = irq_domain_add_linear(node, MAX_INTRS,
+ &irq_generic_chip_ops, NULL);
+ BUG_ON(!zevio_irq_domain);
+
+ ret = irq_alloc_domain_generic_chips(zevio_irq_domain, MAX_INTRS, 1,
+ "zevio_intc", handle_level_irq,
+ clr, 0, IRQ_GC_INIT_MASK_CACHE);
+ BUG_ON(ret);
+
+ gc = irq_get_domain_generic_chip(zevio_irq_domain, 0);
+ gc->reg_base = zevio_irq_io;
+ gc->chip_types[0].chip.irq_ack = zevio_irq_ack;
+ gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
+ gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
+ gc->chip_types[0].regs.mask = IO_IRQ_BASE + IO_ENABLE;
+ gc->chip_types[0].regs.enable = IO_IRQ_BASE + IO_ENABLE;
+ gc->chip_types[0].regs.disable = IO_IRQ_BASE + IO_DISABLE;
+ gc->chip_types[0].regs.ack = IO_IRQ_BASE + IO_RESET;
+
+ set_handle_irq(zevio_handle_irq);
+
+ pr_info("TI-NSPIRE classic IRQ controller\n");
+ return 0;
+}
+
+IRQCHIP_DECLARE(zevio_irq, "lsi,zevio-intc", zevio_of_init);