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From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Date: Fri, 2 Mar 2018 11:06:17 +0000
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Subject: [Qemu-devel] [PULL 16/39] hw/core/split-irq: Device that splits IRQ
lines
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In some board or SoC models it is necessary to split a qemu_irq line
so that one input can feed multiple outputs. We currently have
qemu_irq_split() for this, but that has several deficiencies:
* it can only handle splitting a line into two
* it unavoidably leaks memory, so it can't be used
in a device that can be deleted
Implement a qdev device that encapsulates splitting of IRQs, with a
configurable number of outputs. (This is in some ways the inverse of
the TYPE_OR_IRQ device.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180220180325.29818-13-peter.maydell@linaro.org
---
hw/core/Makefile.objs | 1 +
include/hw/core/split-irq.h | 57 +++++++++++++++++++++++++++++
include/hw/irq.h | 4 +-
hw/core/split-irq.c | 89 +++++++++++++++++++++++++++++++++++++++++=
++++
4 files changed, 150 insertions(+), 1 deletion(-)
create mode 100644 include/hw/core/split-irq.h
create mode 100644 hw/core/split-irq.c
diff --git a/hw/core/Makefile.objs b/hw/core/Makefile.objs
index 1240728c87..eb88ca979e 100644
--- a/hw/core/Makefile.objs
+++ b/hw/core/Makefile.objs
@@ -18,6 +18,7 @@ common-obj-$(CONFIG_FITLOADER) +=3D loader-fit.o
common-obj-$(CONFIG_SOFTMMU) +=3D qdev-properties-system.o
common-obj-$(CONFIG_SOFTMMU) +=3D register.o
common-obj-$(CONFIG_SOFTMMU) +=3D or-irq.o
+common-obj-$(CONFIG_SOFTMMU) +=3D split-irq.o
common-obj-$(CONFIG_PLATFORM_BUS) +=3D platform-bus.o
=20
obj-$(CONFIG_SOFTMMU) +=3D generic-loader.o
diff --git a/include/hw/core/split-irq.h b/include/hw/core/split-irq.h
new file mode 100644
index 0000000000..bb87157c5a
--- /dev/null
+++ b/include/hw/core/split-irq.h
@@ -0,0 +1,57 @@
+/*
+ * IRQ splitter device.
+ *
+ * Copyright (c) 2018 Linaro Limited.
+ * Written by Peter Maydell
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a=
copy
+ * of this software and associated documentation files (the "Software"), t=
o deal
+ * in the Software without restriction, including without limitation the r=
ights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or se=
ll
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included=
in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS=
OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OT=
HER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING=
FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS =
IN
+ * THE SOFTWARE.
+ */
+
+/* This is a simple device which has one GPIO input line and multiple
+ * GPIO output lines. Any change on the input line is forwarded to all
+ * of the outputs.
+ *
+ * QEMU interface:
+ * + one unnamed GPIO input: the input line
+ * + N unnamed GPIO outputs: the output lines
+ * + QOM property "num-lines": sets the number of output lines
+ */
+#ifndef HW_SPLIT_IRQ_H
+#define HW_SPLIT_IRQ_H
+
+#include "hw/irq.h"
+#include "hw/sysbus.h"
+#include "qom/object.h"
+
+#define TYPE_SPLIT_IRQ "split-irq"
+
+#define MAX_SPLIT_LINES 16
+
+typedef struct SplitIRQ SplitIRQ;
+
+#define SPLIT_IRQ(obj) OBJECT_CHECK(SplitIRQ, (obj), TYPE_SPLIT_IRQ)
+
+struct SplitIRQ {
+ DeviceState parent_obj;
+
+ qemu_irq out_irq[MAX_SPLIT_LINES];
+ uint16_t num_lines;
+};
+
+#endif
diff --git a/include/hw/irq.h b/include/hw/irq.h
index 4c4c2eaf9a..7a40e3ed26 100644
--- a/include/hw/irq.h
+++ b/include/hw/irq.h
@@ -50,7 +50,9 @@ void qemu_free_irq(qemu_irq irq);
/* Returns a new IRQ with opposite polarity. */
qemu_irq qemu_irq_invert(qemu_irq irq);
=20
-/* Returns a new IRQ which feeds into both the passed IRQs */
+/* Returns a new IRQ which feeds into both the passed IRQs.
+ * It's probably better to use the TYPE_SPLIT_IRQ device instead.
+ */
qemu_irq qemu_irq_split(qemu_irq irq1, qemu_irq irq2);
=20
/* Returns a new IRQ set which connects 1:1 to another IRQ set, which
diff --git a/hw/core/split-irq.c b/hw/core/split-irq.c
new file mode 100644
index 0000000000..7e64cd4969
--- /dev/null
+++ b/hw/core/split-irq.c
@@ -0,0 +1,89 @@
+/*
+ * IRQ splitter device.
+ *
+ * Copyright (c) 2018 Linaro Limited.
+ * Written by Peter Maydell
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a=
copy
+ * of this software and associated documentation files (the "Software"), t=
o deal
+ * in the Software without restriction, including without limitation the r=
ights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or se=
ll
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included=
in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS=
OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OT=
HER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING=
FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS =
IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/core/split-irq.h"
+#include "qapi/error.h"
+
+static void split_irq_handler(void *opaque, int n, int level)
+{
+ SplitIRQ *s =3D SPLIT_IRQ(opaque);
+ int i;
+
+ for (i =3D 0; i < s->num_lines; i++) {
+ qemu_set_irq(s->out_irq[i], level);
+ }
+}
+
+static void split_irq_init(Object *obj)
+{
+ qdev_init_gpio_in(DEVICE(obj), split_irq_handler, 1);
+}
+
+static void split_irq_realize(DeviceState *dev, Error **errp)
+{
+ SplitIRQ *s =3D SPLIT_IRQ(dev);
+
+ if (s->num_lines < 1 || s->num_lines >=3D MAX_SPLIT_LINES) {
+ error_setg(errp,
+ "IRQ splitter number of lines %d is not between 1 and %=
d",
+ s->num_lines, MAX_SPLIT_LINES);
+ return;
+ }
+
+ qdev_init_gpio_out(dev, s->out_irq, s->num_lines);
+}
+
+static Property split_irq_properties[] =3D {
+ DEFINE_PROP_UINT16("num-lines", SplitIRQ, num_lines, 1),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
+static void split_irq_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc =3D DEVICE_CLASS(klass);
+
+ /* No state to reset or migrate */
+ dc->props =3D split_irq_properties;
+ dc->realize =3D split_irq_realize;
+
+ /* Reason: Needs to be wired up to work */
+ dc->user_creatable =3D false;
+}
+
+static const TypeInfo split_irq_type_info =3D {
+ .name =3D TYPE_SPLIT_IRQ,
+ .parent =3D TYPE_DEVICE,
+ .instance_size =3D sizeof(SplitIRQ),
+ .instance_init =3D split_irq_init,
+ .class_init =3D split_irq_class_init,
+};
+
+static void split_irq_register_types(void)
+{
+ type_register_static(&split_irq_type_info);
+}
+
+type_init(split_irq_register_types)
--=20
2.16.2