[PATCH v4 11/17] xtensa: move built-in PIC to drivers/irqchip

Max Filippov
2013-12-01T09:00:00Z

Extract xtensa built-in interrupt controller implementation from
xtensa/kernel/irq.c and move it to other irqchips, providing way to
instantiate it from the device tree.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
Changes v3 -> v4:
- also update matching compatible string used in xtfpga.dtsi

Changes v1 -> v3:
- update compatible string for PIC irqchip

arch/xtensa/boot/dts/xtfpga.dtsi | 2 +-
arch/xtensa/include/asm/irq.h | 7 ++
arch/xtensa/kernel/irq.c | 137 ++++++++-----------------------------
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-xtensa-pic.c | 108 +++++++++++++++++++++++++++++
include/linux/irqchip/xtensa-pic.h | 18 +++++
6 files changed, 165 insertions(+), 108 deletions(-)
create mode 100644 drivers/irqchip/irq-xtensa-pic.c
create mode 100644 include/linux/irqchip/xtensa-pic.h

diff --git a/arch/xtensa/boot/dts/xtfpga.dtsi b/arch/xtensa/boot/dts/xtfpga.dtsi
index 7eda6ec..b042c3f 100644
--- a/arch/xtensa/boot/dts/xtfpga.dtsi
+++ b/arch/xtensa/boot/dts/xtfpga.dtsi
@@ -26,7 +26,7 @@
};

pic: pic {
- compatible = "xtensa,pic";
+ compatible = "cdns,xtensa-pic";
/* one cell: internal irq number,
* two cells: second cell == 0: internal irq number
* second cell == 1: external irq number
diff --git a/arch/xtensa/include/asm/irq.h b/arch/xtensa/include/asm/irq.h
index 4c0ccc9..16464f2 100644
--- a/arch/xtensa/include/asm/irq.h
+++ b/arch/xtensa/include/asm/irq.h
@@ -43,5 +43,12 @@ static __inline__ int irq_canonicalize(int irq)
}

struct irqaction;
+struct irq_domain;
+
+int xtensa_irq_domain_xlate(const u32 *intspec, unsigned int intsize,
+ unsigned long int_irq, unsigned long ext_irq,
+ unsigned long *out_hwirq, unsigned int *out_type);
+int xtensa_irq_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw);
+unsigned xtensa_map_ext_irq(unsigned ext_irq);

#endif /* _XTENSA_IRQ_H */
diff --git a/arch/xtensa/kernel/irq.c b/arch/xtensa/kernel/irq.c
index 6f4f974..ada1e48 100644
--- a/arch/xtensa/kernel/irq.c
+++ b/arch/xtensa/kernel/irq.c
@@ -18,28 +18,20 @@
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel_stat.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/xtensa-pic.h>
#include <linux/irqdomain.h>
#include <linux/of.h>

#include <asm/uaccess.h>
#include <asm/platform.h>

-static unsigned int cached_irq_mask;
-
atomic_t irq_err_count;

-static struct irq_domain *root_domain;
-
-/*
- * do_IRQ handles all normal device IRQ's (the special
- * SMP cross-CPU interrupts have their own specific
- * handlers).
- */
-
asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
- int irq = irq_find_mapping(root_domain, hwirq);
+ int irq = irq_find_mapping(NULL, hwirq);

if (hwirq >= NR_IRQS) {
printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
@@ -74,83 +66,57 @@ int arch_show_interrupts(struct seq_file *p, int prec)
return 0;
}

-static void xtensa_irq_mask(struct irq_data *d)
-{
- cached_irq_mask &= ~(1 << d->hwirq);
- set_sr (cached_irq_mask, intenable);
-}
-
-static void xtensa_irq_unmask(struct irq_data *d)
-{
- cached_irq_mask |= 1 << d->hwirq;
- set_sr (cached_irq_mask, intenable);
-}
-
-static void xtensa_irq_enable(struct irq_data *d)
-{
- variant_irq_enable(d->hwirq);
- xtensa_irq_unmask(d);
-}
-
-static void xtensa_irq_disable(struct irq_data *d)
-{
- xtensa_irq_mask(d);
- variant_irq_disable(d->hwirq);
-}
-
-static void xtensa_irq_ack(struct irq_data *d)
-{
- set_sr(1 << d->hwirq, intclear);
-}
-
-static int xtensa_irq_retrigger(struct irq_data *d)
+int xtensa_irq_domain_xlate(const u32 *intspec, unsigned int intsize,
+ unsigned long int_irq, unsigned long ext_irq,
+ unsigned long *out_hwirq, unsigned int *out_type)
{
- set_sr(1 << d->hwirq, intset);
- return 1;
+ if (WARN_ON(intsize < 1 || intsize > 2))
+ return -EINVAL;
+ if (intsize == 2 && intspec[1] == 1) {
+ int_irq = xtensa_map_ext_irq(ext_irq);
+ if (int_irq < XCHAL_NUM_INTERRUPTS)
+ *out_hwirq = int_irq;
+ else
+ return -EINVAL;
+ } else {
+ *out_hwirq = int_irq;
+ }
+ *out_type = IRQ_TYPE_NONE;
+ return 0;
}

-static struct irq_chip xtensa_irq_chip = {
- .name = "xtensa",
- .irq_enable = xtensa_irq_enable,
- .irq_disable = xtensa_irq_disable,
- .irq_mask = xtensa_irq_mask,
- .irq_unmask = xtensa_irq_unmask,
- .irq_ack = xtensa_irq_ack,
- .irq_retrigger = xtensa_irq_retrigger,
-};
-
-static int xtensa_irq_map(struct irq_domain *d, unsigned int irq,
+int xtensa_irq_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hw)
{
+ struct irq_chip *irq_chip = d->host_data;
u32 mask = 1 << hw;

if (mask & XCHAL_INTTYPE_MASK_SOFTWARE) {
- irq_set_chip_and_handler_name(irq, &xtensa_irq_chip,
+ irq_set_chip_and_handler_name(irq, irq_chip,
handle_simple_irq, "level");
irq_set_status_flags(irq, IRQ_LEVEL);
} else if (mask & XCHAL_INTTYPE_MASK_EXTERN_EDGE) {
- irq_set_chip_and_handler_name(irq, &xtensa_irq_chip,
+ irq_set_chip_and_handler_name(irq, irq_chip,
handle_edge_irq, "edge");
irq_clear_status_flags(irq, IRQ_LEVEL);
} else if (mask & XCHAL_INTTYPE_MASK_EXTERN_LEVEL) {
- irq_set_chip_and_handler_name(irq, &xtensa_irq_chip,
+ irq_set_chip_and_handler_name(irq, irq_chip,
handle_level_irq, "level");
irq_set_status_flags(irq, IRQ_LEVEL);
} else if (mask & XCHAL_INTTYPE_MASK_TIMER) {
- irq_set_chip_and_handler_name(irq, &xtensa_irq_chip,
- handle_edge_irq, "edge");
+ irq_set_chip_and_handler_name(irq, irq_chip,
+ handle_percpu_irq, "timer");
irq_clear_status_flags(irq, IRQ_LEVEL);
} else {/* XCHAL_INTTYPE_MASK_WRITE_ERROR */
/* XCHAL_INTTYPE_MASK_NMI */
-
- irq_set_chip_and_handler_name(irq, &xtensa_irq_chip,
+ irq_set_chip_and_handler_name(irq, irq_chip,
handle_level_irq, "level");
irq_set_status_flags(irq, IRQ_LEVEL);
}
return 0;
}

-static unsigned map_ext_irq(unsigned ext_irq)
+unsigned xtensa_map_ext_irq(unsigned ext_irq)
{
unsigned mask = XCHAL_INTTYPE_MASK_EXTERN_EDGE |
XCHAL_INTTYPE_MASK_EXTERN_LEVEL;
@@ -163,55 +129,12 @@ static unsigned map_ext_irq(unsigned ext_irq)
return XCHAL_NUM_INTERRUPTS;
}

-/*
- * Device Tree IRQ specifier translation function which works with one or
- * two cell bindings. First cell value maps directly to the hwirq number.
- * Second cell if present specifies whether hwirq number is external (1) or
- * internal (0).
- */
-int xtensa_irq_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
- const u32 *intspec, unsigned int intsize,
- unsigned long *out_hwirq, unsigned int *out_type)
-{
- if (WARN_ON(intsize < 1 || intsize > 2))
- return -EINVAL;
- if (intsize == 2 && intspec[1] == 1) {
- unsigned int_irq = map_ext_irq(intspec[0]);
- if (int_irq < XCHAL_NUM_INTERRUPTS)
- *out_hwirq = int_irq;
- else
- return -EINVAL;
- } else {
- *out_hwirq = intspec[0];
- }
- *out_type = IRQ_TYPE_NONE;
- return 0;
-}
-
-static const struct irq_domain_ops xtensa_irq_domain_ops = {
- .xlate = xtensa_irq_domain_xlate,
- .map = xtensa_irq_map,
-};
-
void __init init_IRQ(void)
{
- struct device_node *intc = NULL;
-
- cached_irq_mask = 0;
- set_sr(~0, intclear);
-
#ifdef CONFIG_OF
- /* The interrupt controller device node is mandatory */
- intc = of_find_compatible_node(NULL, NULL, "xtensa,pic");
- BUG_ON(!intc);
-
- root_domain = irq_domain_add_linear(intc, NR_IRQS,
- &xtensa_irq_domain_ops, NULL);
+ irqchip_init();
#else
- root_domain = irq_domain_add_legacy(intc, NR_IRQS, 0, 0,
- &xtensa_irq_domain_ops, NULL);
+ xtensa_pic_init_legacy(NULL);
#endif
- irq_set_default_host(root_domain);
-
variant_init_irq();
}
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index c60b901..c81a7f3 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -22,3 +22,4 @@ obj-$(CONFIG_RENESAS_IRQC) += irq-renesas-irqc.o
obj-$(CONFIG_VERSATILE_FPGA_IRQ) += irq-versatile-fpga.o
obj-$(CONFIG_ARCH_VT8500) += irq-vt8500.o
obj-$(CONFIG_TB10X_IRQC) += irq-tb10x.o
+obj-$(CONFIG_XTENSA) += irq-xtensa-pic.o
diff --git a/drivers/irqchip/irq-xtensa-pic.c b/drivers/irqchip/irq-xtensa-pic.c
new file mode 100644
index 0000000..7d71126
--- /dev/null
+++ b/drivers/irqchip/irq-xtensa-pic.c
@@ -0,0 +1,108 @@
+/*
+ * Xtensa built-in interrupt controller
+ *
+ * Copyright (C) 2002 - 2013 Tensilica, Inc.
+ * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Chris Zankel <chris@zankel.net>
+ * Kevin Chea
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+
+#include "irqchip.h"
+
+unsigned int cached_irq_mask;
+
+/*
+ * Device Tree IRQ specifier translation function which works with one or
+ * two cell bindings. First cell value maps directly to the hwirq number.
+ * Second cell if present specifies whether hwirq number is external (1) or
+ * internal (0).
+ */
+static int xtensa_pic_irq_domain_xlate(struct irq_domain *d,
+ struct device_node *ctrlr,
+ const u32 *intspec, unsigned int intsize,
+ unsigned long *out_hwirq, unsigned int *out_type)
+{
+ return xtensa_irq_domain_xlate(intspec, intsize,
+ intspec[0], intspec[0],
+ out_hwirq, out_type);
+}
+
+static const struct irq_domain_ops xtensa_irq_domain_ops = {
+ .xlate = xtensa_pic_irq_domain_xlate,
+ .map = xtensa_irq_map,
+};
+
+static void xtensa_irq_mask(struct irq_data *d)
+{
+ cached_irq_mask &= ~(1 << d->hwirq);
+ set_sr(cached_irq_mask, intenable);
+}
+
+static void xtensa_irq_unmask(struct irq_data *d)
+{
+ cached_irq_mask |= 1 << d->hwirq;
+ set_sr(cached_irq_mask, intenable);
+}
+
+static void xtensa_irq_enable(struct irq_data *d)
+{
+ variant_irq_enable(d->hwirq);
+ xtensa_irq_unmask(d);
+}
+
+static void xtensa_irq_disable(struct irq_data *d)
+{
+ xtensa_irq_mask(d);
+ variant_irq_disable(d->hwirq);
+}
+
+static void xtensa_irq_ack(struct irq_data *d)
+{
+ set_sr(1 << d->hwirq, intclear);
+}
+
+static int xtensa_irq_retrigger(struct irq_data *d)
+{
+ set_sr(1 << d->hwirq, intset);
+ return 1;
+}
+
+static struct irq_chip xtensa_irq_chip = {
+ .name = "xtensa",
+ .irq_enable = xtensa_irq_enable,
+ .irq_disable = xtensa_irq_disable,
+ .irq_mask = xtensa_irq_mask,
+ .irq_unmask = xtensa_irq_unmask,
+ .irq_ack = xtensa_irq_ack,
+ .irq_retrigger = xtensa_irq_retrigger,
+};
+
+int __init xtensa_pic_init_legacy(struct device_node *interrupt_parent)
+{
+ struct irq_domain *root_domain =
+ irq_domain_add_legacy(NULL, NR_IRQS, 0, 0,
+ &xtensa_irq_domain_ops, &xtensa_irq_chip);
+ irq_set_default_host(root_domain);
+ return 0;
+}
+
+static int __init xtensa_pic_init(struct device_node *np,
+ struct device_node *interrupt_parent)
+{
+ struct irq_domain *root_domain =
+ irq_domain_add_linear(np, NR_IRQS, &xtensa_irq_domain_ops,
+ &xtensa_irq_chip);
+ irq_set_default_host(root_domain);
+ return 0;
+}
+IRQCHIP_DECLARE(xtensa_irq_chip, "cdns,xtensa-pic", xtensa_pic_init);
diff --git a/include/linux/irqchip/xtensa-pic.h b/include/linux/irqchip/xtensa-pic.h
new file mode 100644
index 0000000..48718ae
--- /dev/null
+++ b/include/linux/irqchip/xtensa-pic.h
@@ -0,0 +1,18 @@
+/*
+ * Xtensa built-in interrupt controller
+ *
+ * Copyright (C) 2002 - 2013 Tensilica, Inc.
+ * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#ifndef __LINUX_IRQCHIP_XTENSA_PIC_H
+#define __LINUX_IRQCHIP_XTENSA_PIC_H
+
+struct device_node;
+int xtensa_pic_init_legacy(struct device_node *interrupt_parent);
+
+#endif /* __LINUX_IRQCHIP_XTENSA_PIC_H */
--
1.8.1.4