[PATCH v2 12/29] nios2: Interrupt handling

Ley Foon Tan
2014-07-15T08:48:21Z

This patch adds the support for IRQ handling.

Signed-off-by: Ley Foon Tan <lftan@altera.com>
---
arch/nios2/include/asm/irq.h | 34 +++++++++++++++
arch/nios2/include/asm/irqflags.h | 69 ++++++++++++++++++++++++++++++
arch/nios2/kernel/irq.c | 90 +++++++++++++++++++++++++++++++++++++++
3 files changed, 193 insertions(+)
create mode 100644 arch/nios2/include/asm/irq.h
create mode 100644 arch/nios2/include/asm/irqflags.h
create mode 100644 arch/nios2/kernel/irq.c

diff --git a/arch/nios2/include/asm/irq.h b/arch/nios2/include/asm/irq.h
new file mode 100644
index 0000000..f7e94b9
--- /dev/null
+++ b/arch/nios2/include/asm/irq.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2013 Altera Corporation
+ * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef _ASM_NIOS2_IRQ_H
+#define _ASM_NIOS2_IRQ_H
+
+#define NIOS2_CPU_NR_IRQS 32
+/* Reserve 32 additional interrupts for GPIO IRQs */
+#define NR_IRQS (NIOS2_CPU_NR_IRQS + 32)
+
+#ifndef NO_IRQ
+#define NO_IRQ (-1)
+#endif
+
+#include <asm-generic/irq.h>
+#include <linux/irqdomain.h>
+
+#endif
diff --git a/arch/nios2/include/asm/irqflags.h b/arch/nios2/include/asm/irqflags.h
new file mode 100644
index 0000000..e91f4f0
--- /dev/null
+++ b/arch/nios2/include/asm/irqflags.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#ifndef _ASM_IRQFLAGS_H
+#define _ASM_IRQFLAGS_H
+
+#include <asm/registers.h>
+
+static inline unsigned long arch_local_save_flags(void)
+{
+ return RDCTL(CTL_STATUS);
+}
+
+/*
+ * This will restore ALL status register flags, not only the interrupt
+ * mask flag.
+ */
+static inline void arch_local_irq_restore(unsigned long flags)
+{
+ WRCTL(CTL_STATUS, flags);
+}
+
+static inline void arch_local_irq_disable(void)
+{
+ unsigned long flags;
+ flags = arch_local_save_flags();
+ arch_local_irq_restore(flags & ~STATUS_PIE);
+}
+
+static inline void arch_local_irq_enable(void)
+{
+ unsigned long flags;
+ flags = arch_local_save_flags();
+ arch_local_irq_restore(flags | STATUS_PIE);
+}
+
+static inline int arch_irqs_disabled_flags(unsigned long flags)
+{
+ return (flags & STATUS_PIE) == 0;
+}
+
+static inline int arch_irqs_disabled(void)
+{
+ return arch_irqs_disabled_flags(arch_local_save_flags());
+}
+
+static inline unsigned long arch_local_irq_save(void)
+{
+ unsigned long flags;
+ flags = arch_local_save_flags();
+ arch_local_irq_restore(flags & ~STATUS_PIE);
+ return flags;
+}
+
+#endif /* _ASM_IRQFLAGS_H */
diff --git a/arch/nios2/kernel/irq.c b/arch/nios2/kernel/irq.c
new file mode 100644
index 0000000..8770d50
--- /dev/null
+++ b/arch/nios2/kernel/irq.c
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2013 Altera Corporation
+ * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
+ * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
+ *
+ * based on irq.c from m68k which is:
+ *
+ * Copyright (C) 2007 Greg Ungerer <gerg@snapgear.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+
+asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs)
+{
+ struct pt_regs *oldregs = set_irq_regs(regs);
+ int irq;
+
+ irq_enter();
+ irq = irq_find_mapping(NULL, hwirq);
+ generic_handle_irq(irq);
+ irq_exit();
+
+ set_irq_regs(oldregs);
+}
+
+static void chip_unmask(struct irq_data *d)
+{
+ u32 ien;
+ ien = RDCTL(CTL_IENABLE);
+ ien |= (1 << d->hwirq);
+ WRCTL(CTL_IENABLE, ien);
+}
+
+static void chip_mask(struct irq_data *d)
+{
+ u32 ien;
+ ien = RDCTL(CTL_IENABLE);
+ ien &= ~(1 << d->hwirq);
+ WRCTL(CTL_IENABLE, ien);
+}
+
+static struct irq_chip m_irq_chip = {
+ .name = "NIOS2-INTC",
+ .irq_unmask = chip_unmask,
+ .irq_mask = chip_mask,
+};
+
+static int irq_map(struct irq_domain *h, unsigned int virq,
+ irq_hw_number_t hw_irq_num)
+{
+ irq_set_chip_and_handler(virq, &m_irq_chip, handle_level_irq);
+
+ return 0;
+}
+
+static struct irq_domain_ops irq_ops = {
+ .map = irq_map,
+ .xlate = irq_domain_xlate_onecell,
+};
+
+void __init init_IRQ(void)
+{
+ struct irq_domain *domain;
+ struct device_node *node;
+
+ node = of_find_compatible_node(NULL, NULL, "altr,nios2-1.0");
+ BUG_ON(!node);
+
+ domain = irq_domain_add_linear(node, NIOS2_CPU_NR_IRQS, &irq_ops, NULL);
+ BUG_ON(!domain);
+
+ irq_set_default_host(domain);
+ of_node_put(node);
+}
--
1.8.2.1