1/*
2 * Copyright (c) 2018, Impinj, Inc.
3 *
4 * i.MX2 Watchdog IP block
5 *
6 * Author: Andrey Smirnov <andrew.smirnov@gmail.com>
7 *
8 * This work is licensed under the terms of the GNU GPL, version 2 or later.
9 * See the COPYING file in the top-level directory.
10 */
11
12#include "qemu/osdep.h"
13#include "qemu/bitops.h"
14#include "qemu/module.h"
15#include "sysemu/watchdog.h"
16
17#include "hw/misc/imx2_wdt.h"
18
19#define IMX2_WDT_WCR_WDA BIT(5) /* -> External Reset WDOG_B */
20#define IMX2_WDT_WCR_SRS BIT(4) /* -> Software Reset Signal */
21
22static uint64_t imx2_wdt_read(void *opaque, hwaddr addr,
23 unsigned int size)
24{
25 return 0;
26}
27
28static void imx2_wdt_write(void *opaque, hwaddr addr,
29 uint64_t value, unsigned int size)
30{
31 if (addr == IMX2_WDT_WCR &&
32 (value & (IMX2_WDT_WCR_WDA | IMX2_WDT_WCR_SRS))) {
33 watchdog_perform_action();
34 }
35}
36
37static const MemoryRegionOps imx2_wdt_ops = {
38 .read = imx2_wdt_read,
39 .write = imx2_wdt_write,
40 .endianness = DEVICE_NATIVE_ENDIAN,
41 .impl = {
42 /*
43 * Our device would not work correctly if the guest was doing
44 * unaligned access. This might not be a limitation on the
45 * real device but in practice there is no reason for a guest
46 * to access this device unaligned.
47 */
48 .min_access_size = 4,
49 .max_access_size = 4,
50 .unaligned = false,
51 },
52};
53
54static void imx2_wdt_realize(DeviceState *dev, Error **errp)
55{
56 IMX2WdtState *s = IMX2_WDT(dev);
57
58 memory_region_init_io(&s->mmio, OBJECT(dev),
59 &imx2_wdt_ops, s,
60 TYPE_IMX2_WDT".mmio",
61 IMX2_WDT_REG_NUM * sizeof(uint16_t));
62 sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio);
63}
64
65static void imx2_wdt_class_init(ObjectClass *klass, void *data)
66{
67 DeviceClass *dc = DEVICE_CLASS(klass);
68
69 dc->realize = imx2_wdt_realize;
70 set_bit(DEVICE_CATEGORY_MISC, dc->categories);
71}
72
73static const TypeInfo imx2_wdt_info = {
74 .name = TYPE_IMX2_WDT,
75 .parent = TYPE_SYS_BUS_DEVICE,
76 .instance_size = sizeof(IMX2WdtState),
77 .class_init = imx2_wdt_class_init,
78};
79
80static WatchdogTimerModel model = {
81 .wdt_name = "imx2-watchdog",
82 .wdt_description = "i.MX2 Watchdog",
83};
84
85static void imx2_wdt_register_type(void)
86{
87 watchdog_add_model(&model);
88 type_register_static(&imx2_wdt_info);
89}
90type_init(imx2_wdt_register_type)
91