[PATCH 4/5] irqchip: add sa1100 driver

Dmitry Eremin-Solenikov
2015-01-15T10:10:41Z

Add an irqchip driver for Intel StrongARM SA-11x0 family of chips. For
now it is just a copy of the current arch/arm/mach-sa1100/irq.c driver.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
---
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-sa11x0.c | 185 +++++++++++++++++++++++++++++++++++++
include/linux/irqchip/irq-sa11x0.h | 18 ++++
3 files changed, 204 insertions(+)
create mode 100644 drivers/irqchip/irq-sa11x0.c
create mode 100644 include/linux/irqchip/irq-sa11x0.h

diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 9516a32..b0d1dde 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -42,3 +42,4 @@ obj-$(CONFIG_BRCMSTB_L2_IRQ) += irq-brcmstb-l2.o
obj-$(CONFIG_KEYSTONE_IRQ) += irq-keystone.o
obj-$(CONFIG_MIPS_GIC) += irq-mips-gic.o
obj-$(CONFIG_ARCH_MEDIATEK) += irq-mtk-sysirq.o
+obj-$(CONFIG_ARCH_SA1100) += irq-sa11x0.o
diff --git a/drivers/irqchip/irq-sa11x0.c b/drivers/irqchip/irq-sa11x0.c
new file mode 100644
index 0000000..c840187
--- /dev/null
+++ b/drivers/irqchip/irq-sa11x0.c
@@ -0,0 +1,185 @@
+/*
+ * drivers/irqchip/irq-sa11x0.c
+ *
+ * Copyright (C) 1999-2001 Nicolas Pitre
+ *
+ * Generic IRQ handling for the SA11x0.
+ *
+ * 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/init.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/syscore_ops.h>
+#include <linux/irqchip/irq-sa11x0.h>
+
+#include <asm/exception.h>
+
+#define ICIP 0x00 /* IC IRQ Pending reg. */
+#define ICMR 0x04 /* IC Mask Reg. */
+#define ICLR 0x08 /* IC Level Reg. */
+#define ICCR 0x0C /* IC Control Reg. */
+#define ICFP 0x10 /* IC FIQ Pending reg. */
+#define ICPR 0x20 /* IC Pending Reg. */
+
+static void __iomem *iobase;
+static DEFINE_RAW_SPINLOCK(lock);
+
+/*
+ * We don't need to ACK IRQs on the SA1100 unless they're GPIOs
+ * this is for internal IRQs i.e. from IRQ LCD to RTCAlrm.
+ */
+static void sa1100_mask_irq(struct irq_data *d)
+{
+ u32 reg;
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&lock, flags);
+
+ reg = readl_relaxed(iobase + ICMR);
+ reg &= ~BIT(d->hwirq);
+ writel_relaxed(reg, iobase + ICMR);
+
+ raw_spin_unlock_irqrestore(&lock, flags);
+}
+
+static void sa1100_unmask_irq(struct irq_data *d)
+{
+ u32 reg;
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&lock, flags);
+
+ reg = readl_relaxed(iobase + ICMR);
+ reg |= BIT(d->hwirq);
+ writel_relaxed(reg, iobase + ICMR);
+
+ raw_spin_unlock_irqrestore(&lock, flags);
+}
+
+static int sa1100_set_wake(struct irq_data *d, unsigned int on)
+{
+ return sa11x0_sc_set_wake(d->hwirq, on);
+}
+
+static struct irq_chip sa1100_normal_chip = {
+ .name = "SC",
+ .irq_ack = sa1100_mask_irq,
+ .irq_mask = sa1100_mask_irq,
+ .irq_unmask = sa1100_unmask_irq,
+ .irq_set_wake = sa1100_set_wake,
+};
+
+static int sa1100_normal_irqdomain_map(struct irq_domain *d,
+ unsigned int irq, irq_hw_number_t hwirq)
+{
+ irq_set_chip_and_handler(irq, &sa1100_normal_chip,
+ handle_level_irq);
+ set_irq_flags(irq, IRQF_VALID);
+
+ return 0;
+}
+
+static struct irq_domain_ops sa1100_normal_irqdomain_ops = {
+ .map = sa1100_normal_irqdomain_map,
+ .xlate = irq_domain_xlate_onetwocell,
+};
+
+static struct irq_domain *sa1100_normal_irqdomain;
+
+static struct sa1100irq_state {
+ unsigned int saved;
+ unsigned int icmr;
+ unsigned int iclr;
+ unsigned int iccr;
+} sa1100irq_state;
+
+static int sa1100irq_suspend(void)
+{
+ struct sa1100irq_state *st = &sa1100irq_state;
+
+ st->saved = 1;
+ st->icmr = readl_relaxed(iobase + ICMR);
+ st->iclr = readl_relaxed(iobase + ICLR);
+ st->iccr = readl_relaxed(iobase + ICCR);
+
+ /*
+ * Disable all GPIO-based interrupts.
+ */
+ writel_relaxed(st->icmr & 0xfffff000, iobase + ICMR);
+
+ return 0;
+}
+
+static void sa1100irq_resume(void)
+{
+ struct sa1100irq_state *st = &sa1100irq_state;
+
+ if (st->saved) {
+ writel_relaxed(st->iccr, iobase + ICCR);
+ writel_relaxed(st->iclr, iobase + ICLR);
+
+ writel_relaxed(st->icmr, iobase + ICMR);
+ }
+}
+
+static struct syscore_ops sa1100irq_syscore_ops = {
+ .suspend = sa1100irq_suspend,
+ .resume = sa1100irq_resume,
+};
+
+static int __init sa1100irq_init_devicefs(void)
+{
+ register_syscore_ops(&sa1100irq_syscore_ops);
+ return 0;
+}
+
+device_initcall(sa1100irq_init_devicefs);
+
+static asmlinkage void __exception_irq_entry
+sa1100_handle_irq(struct pt_regs *regs)
+{
+ uint32_t icip, icmr, mask;
+
+ do {
+ icip = readl_relaxed(iobase + ICIP);
+ icmr = readl_relaxed(iobase + ICMR);
+ mask = icip & icmr;
+
+ if (mask == 0)
+ break;
+
+ handle_domain_irq(sa1100_normal_irqdomain,
+ ffs(mask) - 1, regs);
+ } while (1);
+}
+
+void __init sa11x0_init_irq_nodt(int irq_start, resource_size_t io_start)
+{
+ iobase = ioremap(io_start, SZ_64K);
+ if (WARN_ON(!iobase))
+ return;
+
+ /* disable all IRQs */
+ writel_relaxed(0, iobase + ICMR);
+
+ /* all IRQs are IRQ, not FIQ */
+ writel_relaxed(0, iobase + ICLR);
+
+ /*
+ * Whatever the doc says, this has to be set for the wait-on-irq
+ * instruction to work... on a SA1100 rev 9 at least.
+ */
+ writel_relaxed(1, iobase + ICCR);
+
+ sa1100_normal_irqdomain = irq_domain_add_simple(NULL,
+ 32, irq_start,
+ &sa1100_normal_irqdomain_ops, NULL);
+
+ set_handle_irq(sa1100_handle_irq);
+}
diff --git a/include/linux/irqchip/irq-sa11x0.h b/include/linux/irqchip/irq-sa11x0.h
new file mode 100644
index 0000000..38ebe2f
--- /dev/null
+++ b/include/linux/irqchip/irq-sa11x0.h
@@ -0,0 +1,18 @@
+/*
+ * Generic IRQ handling for the SA11x0.
+ *
+ * Copyright (C) 1999-2001 Nicolas Pitre
+ *
+ * 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.
+ */
+
+#ifndef __INCLUDE_LINUX_IRQCHIP_IRQ_SA11x0_H
+#define __INCLUDE_LINUX_IRQCHIP_IRQ_SA11x0_H
+
+void __init sa11x0_init_irq_nodt(int irq_start, resource_size_t io_start);
+int sa11x0_gpio_set_wake(unsigned int gpio, unsigned int on);
+int sa11x0_sc_set_wake(unsigned int irq, unsigned int on);
+
+#endif
--
2.1.4