diff options
author | Peter Maydell <peter.maydell@linaro.org> | 2018-03-02 10:45:38 +0000 |
---|---|---|
committer | Peter Maydell <peter.maydell@linaro.org> | 2018-03-02 11:03:45 +0000 |
commit | 5edb1b3fa93217cf7adc50725a69ab0cefcea973 (patch) | |
tree | 0cce7bbddb09998b7162d7da5fcb6e2c31c7811d /include | |
parent | 4a151677a8ea80e65f519fed1df92c0db6350a02 (diff) |
hw/core/split-irq: Device that splits IRQ lines
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
Diffstat (limited to 'include')
-rw-r--r-- | include/hw/core/split-irq.h | 57 | ||||
-rw-r--r-- | include/hw/irq.h | 4 |
2 files changed, 60 insertions, 1 deletions
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"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * 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 OTHER + * 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); -/* 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); /* Returns a new IRQ set which connects 1:1 to another IRQ set, which |