From 397e7b515785cad6e10b29f3001fd80c3f519bb8 Mon Sep 17 00:00:00 2001
From: Daniel Tang
Date: Thu, 5 Dec 2013 17:12:17 +1100
Subject: irqchip: Add support for TI-NSPIRE irqchip
This patch adds support for the interrupt controllers found in some
TI-Nspire models.
FIQ support was taken out to simplify the driver code and may be added
in later. Since Linux on this platform doesn't really use FIQs, this
wasn't really that important in the first place.
[ tglx: Made zevio_handle_irq static and reordered __init functions ]
Signed-off-by: Daniel Tang
Acked-by: Grant Likely
Link: http://lkml.kernel.org/r/1386223937-12189-1-git-send-email-dt.tangr@gmail.com
Signed-off-by: Thomas Gleixner
---
drivers/irqchip/irq-zevio.c | 127 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 127 insertions(+)
create mode 100644 drivers/irqchip/irq-zevio.c
(limited to 'drivers/irqchip/irq-zevio.c')
diff --git a/drivers/irqchip/irq-zevio.c b/drivers/irqchip/irq-zevio.c
new file mode 100644
index 0000000..8ed04c4
--- /dev/null
+++ b/drivers/irqchip/irq-zevio.c
@@ -0,0 +1,127 @@
+/*
+ * linux/drivers/irqchip/irq-zevio.c
+ *
+ * Copyright (C) 2013 Daniel Tang
+ *
+ * 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
+#include
+#include
+#include
+#include
+
+#include
+#include
+
+#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 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 =
+ &container_of(irqd->chip, struct irq_chip_type, chip)->regs;
+
+ readl(gc->reg_base + regs->ack);
+}
+
+static asmlinkage 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);
+ irqnr = irq_find_mapping(zevio_irq_domain, irqnr);
+ handle_IRQ(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);
--
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