diff options
Diffstat (limited to 'hw/watchdog/wdt_aspeed.c')
| -rw-r--r-- | hw/watchdog/wdt_aspeed.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/hw/watchdog/wdt_aspeed.c b/hw/watchdog/wdt_aspeed.c new file mode 100644 index 0000000000..8bbe579b6b --- /dev/null +++ b/hw/watchdog/wdt_aspeed.c @@ -0,0 +1,225 @@ +/* + * ASPEED Watchdog Controller + * + * Copyright (C) 2016-2017 IBM Corp. + * + * This code is licensed under the GPL version 2 or later. See the + * COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "qemu/log.h" +#include "sysemu/watchdog.h" +#include "hw/sysbus.h" +#include "qemu/timer.h" +#include "hw/watchdog/wdt_aspeed.h" + +#define WDT_STATUS (0x00 / 4) +#define WDT_RELOAD_VALUE (0x04 / 4) +#define WDT_RESTART (0x08 / 4) +#define WDT_CTRL (0x0C / 4) +#define WDT_CTRL_RESET_MODE_SOC (0x00 << 5) +#define WDT_CTRL_RESET_MODE_FULL_CHIP (0x01 << 5) +#define WDT_CTRL_1MHZ_CLK BIT(4) +#define WDT_CTRL_WDT_EXT BIT(3) +#define WDT_CTRL_WDT_INTR BIT(2) +#define WDT_CTRL_RESET_SYSTEM BIT(1) +#define WDT_CTRL_ENABLE BIT(0) + +#define WDT_TIMEOUT_STATUS (0x10 / 4) +#define WDT_TIMEOUT_CLEAR (0x14 / 4) +#define WDT_RESET_WDITH (0x18 / 4) + +#define WDT_RESTART_MAGIC 0x4755 + +static bool aspeed_wdt_is_enabled(const AspeedWDTState *s) +{ + return s->regs[WDT_CTRL] & WDT_CTRL_ENABLE; +} + +static uint64_t aspeed_wdt_read(void *opaque, hwaddr offset, unsigned size) +{ + AspeedWDTState *s = ASPEED_WDT(opaque); + + offset >>= 2; + + switch (offset) { + case WDT_STATUS: + return s->regs[WDT_STATUS]; + case WDT_RELOAD_VALUE: + return s->regs[WDT_RELOAD_VALUE]; + case WDT_RESTART: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: read from write-only reg at offset 0x%" + HWADDR_PRIx "\n", __func__, offset); + return 0; + case WDT_CTRL: + return s->regs[WDT_CTRL]; + case WDT_TIMEOUT_STATUS: + case WDT_TIMEOUT_CLEAR: + case WDT_RESET_WDITH: + qemu_log_mask(LOG_UNIMP, + "%s: uninmplemented read at offset 0x%" HWADDR_PRIx "\n", + __func__, offset); + return 0; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: Out-of-bounds read at offset 0x%" HWADDR_PRIx "\n", + __func__, offset); + return 0; + } + +} + +static void aspeed_wdt_reload(AspeedWDTState *s, bool pclk) +{ + uint32_t reload; + + if (pclk) { + reload = muldiv64(s->regs[WDT_RELOAD_VALUE], NANOSECONDS_PER_SECOND, + s->pclk_freq); + } else { + reload = s->regs[WDT_RELOAD_VALUE] * 1000; + } + + if (aspeed_wdt_is_enabled(s)) { + timer_mod(s->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + reload); + } +} + +static void aspeed_wdt_write(void *opaque, hwaddr offset, uint64_t data, + unsigned size) +{ + AspeedWDTState *s = ASPEED_WDT(opaque); + bool enable = data & WDT_CTRL_ENABLE; + + offset >>= 2; + + switch (offset) { + case WDT_STATUS: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: write to read-only reg at offset 0x%" + HWADDR_PRIx "\n", __func__, offset); + break; + case WDT_RELOAD_VALUE: + s->regs[WDT_RELOAD_VALUE] = data; + break; + case WDT_RESTART: + if ((data & 0xFFFF) == WDT_RESTART_MAGIC) { + s->regs[WDT_STATUS] = s->regs[WDT_RELOAD_VALUE]; + aspeed_wdt_reload(s, !(data & WDT_CTRL_1MHZ_CLK)); + } + break; + case WDT_CTRL: + if (enable && !aspeed_wdt_is_enabled(s)) { + s->regs[WDT_CTRL] = data; + aspeed_wdt_reload(s, !(data & WDT_CTRL_1MHZ_CLK)); + } else if (!enable && aspeed_wdt_is_enabled(s)) { + s->regs[WDT_CTRL] = data; + timer_del(s->timer); + } + break; + case WDT_TIMEOUT_STATUS: + case WDT_TIMEOUT_CLEAR: + case WDT_RESET_WDITH: + qemu_log_mask(LOG_UNIMP, + "%s: uninmplemented write at offset 0x%" HWADDR_PRIx "\n", + __func__, offset); + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: Out-of-bounds write at offset 0x%" HWADDR_PRIx "\n", + __func__, offset); + } + return; +} + +static WatchdogTimerModel model = { + .wdt_name = TYPE_ASPEED_WDT, + .wdt_description = "Aspeed watchdog device", +}; + +static const VMStateDescription vmstate_aspeed_wdt = { + .name = "vmstate_aspeed_wdt", + .version_id = 0, + .minimum_version_id = 0, + .fields = (VMStateField[]) { + VMSTATE_TIMER_PTR(timer, AspeedWDTState), + VMSTATE_UINT32_ARRAY(regs, AspeedWDTState, ASPEED_WDT_REGS_MAX), + VMSTATE_END_OF_LIST() + } +}; + +static const MemoryRegionOps aspeed_wdt_ops = { + .read = aspeed_wdt_read, + .write = aspeed_wdt_write, + .endianness = DEVICE_LITTLE_ENDIAN, + .valid.min_access_size = 4, + .valid.max_access_size = 4, + .valid.unaligned = false, +}; + +static void aspeed_wdt_reset(DeviceState *dev) +{ + AspeedWDTState *s = ASPEED_WDT(dev); + + s->regs[WDT_STATUS] = 0x3EF1480; + s->regs[WDT_RELOAD_VALUE] = 0x03EF1480; + s->regs[WDT_RESTART] = 0; + s->regs[WDT_CTRL] = 0; + + timer_del(s->timer); +} + +static void aspeed_wdt_timer_expired(void *dev) +{ + AspeedWDTState *s = ASPEED_WDT(dev); + + qemu_log_mask(CPU_LOG_RESET, "Watchdog timer expired.\n"); + watchdog_perform_action(); + timer_del(s->timer); +} + +#define PCLK_HZ 24000000 + +static void aspeed_wdt_realize(DeviceState *dev, Error **errp) +{ + SysBusDevice *sbd = SYS_BUS_DEVICE(dev); + AspeedWDTState *s = ASPEED_WDT(dev); + + s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, aspeed_wdt_timer_expired, dev); + + /* FIXME: This setting should be derived from the SCU hw strapping + * register SCU70 + */ + s->pclk_freq = PCLK_HZ; + + memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_wdt_ops, s, + TYPE_ASPEED_WDT, ASPEED_WDT_REGS_MAX * 4); + sysbus_init_mmio(sbd, &s->iomem); +} + +static void aspeed_wdt_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = aspeed_wdt_realize; + dc->reset = aspeed_wdt_reset; + set_bit(DEVICE_CATEGORY_MISC, dc->categories); + dc->vmsd = &vmstate_aspeed_wdt; +} + +static const TypeInfo aspeed_wdt_info = { + .parent = TYPE_SYS_BUS_DEVICE, + .name = TYPE_ASPEED_WDT, + .instance_size = sizeof(AspeedWDTState), + .class_init = aspeed_wdt_class_init, +}; + +static void wdt_aspeed_register_types(void) +{ + watchdog_add_model(&model); + type_register_static(&aspeed_wdt_info); +} + +type_init(wdt_aspeed_register_types) |