diff options
author | Peter Maydell <peter.maydell@linaro.org> | 2018-08-20 11:24:33 +0100 |
---|---|---|
committer | Peter Maydell <peter.maydell@linaro.org> | 2018-08-20 11:24:33 +0100 |
commit | 050c2ea07b18b77c7562512a2b73e86e48c5c4b7 (patch) | |
tree | 07731b59e0662348f82ecd22782072c5bf6a82e8 | |
parent | 62b9cf0a77b4dd5571a948d798d4604f4ae6bcd5 (diff) |
hw/watchdog/cmsdk_apb_watchdog: Implement CMSDK APB watchdog module
The Arm Cortex-M System Design Kit includes a simple watchdog module
based on a 32-bit down-counter. Implement this.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r-- | MAINTAINERS | 2 | ||||
-rw-r--r-- | Makefile.objs | 1 | ||||
-rw-r--r-- | default-configs/arm-softmmu.mak | 1 | ||||
-rw-r--r-- | hw/watchdog/Makefile.objs | 1 | ||||
-rw-r--r-- | hw/watchdog/cmsdk-apb-watchdog.c | 326 | ||||
-rw-r--r-- | hw/watchdog/trace-events | 6 | ||||
-rw-r--r-- | include/hw/watchdog/cmsdk-apb-watchdog.h | 59 |
7 files changed, 396 insertions, 0 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 70651f7da0..6698a7e0f8 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -456,6 +456,8 @@ F: hw/timer/cmsdk-apb-timer.c F: include/hw/timer/cmsdk-apb-timer.h F: hw/char/cmsdk-apb-uart.c F: include/hw/char/cmsdk-apb-uart.h +F: hw/watchdog/cmsdk-apb-watchdog.c +F: include/hw/watchdog/cmsdk-apb-watchdog.h F: hw/misc/tz-ppc.c F: include/hw/misc/tz-ppc.h F: hw/misc/tz-mpc.c diff --git a/Makefile.objs b/Makefile.objs index 7a9828da28..ce9c79235e 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -240,6 +240,7 @@ trace-events-subdirs += hw/tpm trace-events-subdirs += hw/usb trace-events-subdirs += hw/vfio trace-events-subdirs += hw/virtio +trace-events-subdirs += hw/watchdog trace-events-subdirs += hw/xen trace-events-subdirs += io trace-events-subdirs += linux-user diff --git a/default-configs/arm-softmmu.mak b/default-configs/arm-softmmu.mak index 311584fd74..a92bc34fb2 100644 --- a/default-configs/arm-softmmu.mak +++ b/default-configs/arm-softmmu.mak @@ -104,6 +104,7 @@ CONFIG_STM32F205_SOC=y CONFIG_CMSDK_APB_TIMER=y CONFIG_CMSDK_APB_UART=y +CONFIG_CMSDK_APB_WATCHDOG=y CONFIG_MPS2_FPGAIO=y CONFIG_MPS2_SCC=y diff --git a/hw/watchdog/Makefile.objs b/hw/watchdog/Makefile.objs index 9589bed63a..3f536d1cad 100644 --- a/hw/watchdog/Makefile.objs +++ b/hw/watchdog/Makefile.objs @@ -1,4 +1,5 @@ common-obj-y += watchdog.o +common-obj-$(CONFIG_CMSDK_APB_WATCHDOG) += cmsdk-apb-watchdog.o common-obj-$(CONFIG_WDT_IB6300ESB) += wdt_i6300esb.o common-obj-$(CONFIG_WDT_IB700) += wdt_ib700.o common-obj-$(CONFIG_WDT_DIAG288) += wdt_diag288.o diff --git a/hw/watchdog/cmsdk-apb-watchdog.c b/hw/watchdog/cmsdk-apb-watchdog.c new file mode 100644 index 0000000000..eb79a73fa6 --- /dev/null +++ b/hw/watchdog/cmsdk-apb-watchdog.c @@ -0,0 +1,326 @@ +/* + * ARM CMSDK APB watchdog emulation + * + * Copyright (c) 2018 Linaro Limited + * Written by Peter Maydell + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 or + * (at your option) any later version. + */ + +/* + * This is a model of the "APB watchdog" which is part of the Cortex-M + * System Design Kit (CMSDK) and documented in the Cortex-M System + * Design Kit Technical Reference Manual (ARM DDI0479C): + * https://developer.arm.com/products/system-design/system-design-kits/cortex-m-system-design-kit + */ + +#include "qemu/osdep.h" +#include "qemu/log.h" +#include "trace.h" +#include "qapi/error.h" +#include "qemu/main-loop.h" +#include "sysemu/watchdog.h" +#include "hw/sysbus.h" +#include "hw/registerfields.h" +#include "hw/watchdog/cmsdk-apb-watchdog.h" + +REG32(WDOGLOAD, 0x0) +REG32(WDOGVALUE, 0x4) +REG32(WDOGCONTROL, 0x8) + FIELD(WDOGCONTROL, INTEN, 0, 1) + FIELD(WDOGCONTROL, RESEN, 1, 1) +#define R_WDOGCONTROL_VALID_MASK (R_WDOGCONTROL_INTEN_MASK | \ + R_WDOGCONTROL_RESEN_MASK) +REG32(WDOGINTCLR, 0xc) +REG32(WDOGRIS, 0x10) + FIELD(WDOGRIS, INT, 0, 1) +REG32(WDOGMIS, 0x14) +REG32(WDOGLOCK, 0xc00) +#define WDOG_UNLOCK_VALUE 0x1ACCE551 +REG32(WDOGITCR, 0xf00) + FIELD(WDOGITCR, ENABLE, 0, 1) +#define R_WDOGITCR_VALID_MASK R_WDOGITCR_ENABLE_MASK +REG32(WDOGITOP, 0xf04) + FIELD(WDOGITOP, WDOGRES, 0, 1) + FIELD(WDOGITOP, WDOGINT, 1, 1) +#define R_WDOGITOP_VALID_MASK (R_WDOGITOP_WDOGRES_MASK | \ + R_WDOGITOP_WDOGINT_MASK) +REG32(PID4, 0xfd0) +REG32(PID5, 0xfd4) +REG32(PID6, 0xfd8) +REG32(PID7, 0xfdc) +REG32(PID0, 0xfe0) +REG32(PID1, 0xfe4) +REG32(PID2, 0xfe8) +REG32(PID3, 0xfec) +REG32(CID0, 0xff0) +REG32(CID1, 0xff4) +REG32(CID2, 0xff8) +REG32(CID3, 0xffc) + +/* PID/CID values */ +static const int watchdog_id[] = { + 0x04, 0x00, 0x00, 0x00, /* PID4..PID7 */ + 0x24, 0xb8, 0x1b, 0x00, /* PID0..PID3 */ + 0x0d, 0xf0, 0x05, 0xb1, /* CID0..CID3 */ +}; + +static bool cmsdk_apb_watchdog_intstatus(CMSDKAPBWatchdog *s) +{ + /* Return masked interrupt status */ + return s->intstatus && (s->control & R_WDOGCONTROL_INTEN_MASK); +} + +static bool cmsdk_apb_watchdog_resetstatus(CMSDKAPBWatchdog *s) +{ + /* Return masked reset status */ + return s->resetstatus && (s->control & R_WDOGCONTROL_RESEN_MASK); +} + +static void cmsdk_apb_watchdog_update(CMSDKAPBWatchdog *s) +{ + bool wdogint; + bool wdogres; + + if (s->itcr) { + wdogint = s->itop & R_WDOGITOP_WDOGINT_MASK; + wdogres = s->itop & R_WDOGITOP_WDOGRES_MASK; + } else { + wdogint = cmsdk_apb_watchdog_intstatus(s); + wdogres = cmsdk_apb_watchdog_resetstatus(s); + } + + qemu_set_irq(s->wdogint, wdogint); + if (wdogres) { + watchdog_perform_action(); + } +} + +static uint64_t cmsdk_apb_watchdog_read(void *opaque, hwaddr offset, + unsigned size) +{ + CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(opaque); + uint64_t r; + + switch (offset) { + case A_WDOGLOAD: + r = ptimer_get_limit(s->timer); + break; + case A_WDOGVALUE: + r = ptimer_get_count(s->timer); + break; + case A_WDOGCONTROL: + r = s->control; + break; + case A_WDOGRIS: + r = s->intstatus; + break; + case A_WDOGMIS: + r = cmsdk_apb_watchdog_intstatus(s); + break; + case A_WDOGLOCK: + r = s->lock; + break; + case A_WDOGITCR: + r = s->itcr; + break; + case A_PID4 ... A_CID3: + r = watchdog_id[(offset - A_PID4) / 4]; + break; + case A_WDOGINTCLR: + case A_WDOGITOP: + qemu_log_mask(LOG_GUEST_ERROR, + "CMSDK APB watchdog read: read of WO offset %x\n", + (int)offset); + r = 0; + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "CMSDK APB watchdog read: bad offset %x\n", (int)offset); + r = 0; + break; + } + trace_cmsdk_apb_watchdog_read(offset, r, size); + return r; +} + +static void cmsdk_apb_watchdog_write(void *opaque, hwaddr offset, + uint64_t value, unsigned size) +{ + CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(opaque); + + trace_cmsdk_apb_watchdog_write(offset, value, size); + + if (s->lock && offset != A_WDOGLOCK) { + /* Write access is disabled via WDOGLOCK */ + qemu_log_mask(LOG_GUEST_ERROR, + "CMSDK APB watchdog write: write to locked watchdog\n"); + return; + } + + switch (offset) { + case A_WDOGLOAD: + /* + * Reset the load value and the current count, and make sure + * we're counting. + */ + ptimer_set_limit(s->timer, value, 1); + ptimer_run(s->timer, 0); + break; + case A_WDOGCONTROL: + s->control = value & R_WDOGCONTROL_VALID_MASK; + cmsdk_apb_watchdog_update(s); + break; + case A_WDOGINTCLR: + s->intstatus = 0; + ptimer_set_count(s->timer, ptimer_get_limit(s->timer)); + cmsdk_apb_watchdog_update(s); + break; + case A_WDOGLOCK: + s->lock = (value != WDOG_UNLOCK_VALUE); + break; + case A_WDOGITCR: + s->itcr = value & R_WDOGITCR_VALID_MASK; + cmsdk_apb_watchdog_update(s); + break; + case A_WDOGITOP: + s->itop = value & R_WDOGITOP_VALID_MASK; + cmsdk_apb_watchdog_update(s); + break; + case A_WDOGVALUE: + case A_WDOGRIS: + case A_WDOGMIS: + case A_PID4 ... A_CID3: + qemu_log_mask(LOG_GUEST_ERROR, + "CMSDK APB watchdog write: write to RO offset 0x%x\n", + (int)offset); + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "CMSDK APB watchdog write: bad offset 0x%x\n", + (int)offset); + break; + } +} + +static const MemoryRegionOps cmsdk_apb_watchdog_ops = { + .read = cmsdk_apb_watchdog_read, + .write = cmsdk_apb_watchdog_write, + .endianness = DEVICE_LITTLE_ENDIAN, + /* byte/halfword accesses are just zero-padded on reads and writes */ + .impl.min_access_size = 4, + .impl.max_access_size = 4, + .valid.min_access_size = 1, + .valid.max_access_size = 4, +}; + +static void cmsdk_apb_watchdog_tick(void *opaque) +{ + CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(opaque); + + if (!s->intstatus) { + /* Count expired for the first time: raise interrupt */ + s->intstatus = R_WDOGRIS_INT_MASK; + } else { + /* Count expired for the second time: raise reset and stop clock */ + s->resetstatus = 1; + ptimer_stop(s->timer); + } + cmsdk_apb_watchdog_update(s); +} + +static void cmsdk_apb_watchdog_reset(DeviceState *dev) +{ + CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(dev); + + trace_cmsdk_apb_watchdog_reset(); + s->control = 0; + s->intstatus = 0; + s->lock = 0; + s->itcr = 0; + s->itop = 0; + s->resetstatus = 0; + /* Set the limit and the count */ + ptimer_set_limit(s->timer, 0xffffffff, 1); + ptimer_run(s->timer, 0); +} + +static void cmsdk_apb_watchdog_init(Object *obj) +{ + SysBusDevice *sbd = SYS_BUS_DEVICE(obj); + CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(obj); + + memory_region_init_io(&s->iomem, obj, &cmsdk_apb_watchdog_ops, + s, "cmsdk-apb-watchdog", 0x1000); + sysbus_init_mmio(sbd, &s->iomem); + sysbus_init_irq(sbd, &s->wdogint); +} + +static void cmsdk_apb_watchdog_realize(DeviceState *dev, Error **errp) +{ + CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(dev); + QEMUBH *bh; + + if (s->wdogclk_frq == 0) { + error_setg(errp, + "CMSDK APB watchdog: wdogclk-frq property must be set"); + return; + } + + bh = qemu_bh_new(cmsdk_apb_watchdog_tick, s); + s->timer = ptimer_init(bh, + PTIMER_POLICY_WRAP_AFTER_ONE_PERIOD | + PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT | + PTIMER_POLICY_NO_IMMEDIATE_RELOAD | + PTIMER_POLICY_NO_COUNTER_ROUND_DOWN); + + ptimer_set_freq(s->timer, s->wdogclk_frq); +} + +static const VMStateDescription cmsdk_apb_watchdog_vmstate = { + .name = "cmsdk-apb-watchdog", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_PTIMER(timer, CMSDKAPBWatchdog), + VMSTATE_UINT32(control, CMSDKAPBWatchdog), + VMSTATE_UINT32(intstatus, CMSDKAPBWatchdog), + VMSTATE_UINT32(lock, CMSDKAPBWatchdog), + VMSTATE_UINT32(itcr, CMSDKAPBWatchdog), + VMSTATE_UINT32(itop, CMSDKAPBWatchdog), + VMSTATE_UINT32(resetstatus, CMSDKAPBWatchdog), + VMSTATE_END_OF_LIST() + } +}; + +static Property cmsdk_apb_watchdog_properties[] = { + DEFINE_PROP_UINT32("wdogclk-frq", CMSDKAPBWatchdog, wdogclk_frq, 0), + DEFINE_PROP_END_OF_LIST(), +}; + +static void cmsdk_apb_watchdog_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = cmsdk_apb_watchdog_realize; + dc->vmsd = &cmsdk_apb_watchdog_vmstate; + dc->reset = cmsdk_apb_watchdog_reset; + dc->props = cmsdk_apb_watchdog_properties; +} + +static const TypeInfo cmsdk_apb_watchdog_info = { + .name = TYPE_CMSDK_APB_WATCHDOG, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(CMSDKAPBWatchdog), + .instance_init = cmsdk_apb_watchdog_init, + .class_init = cmsdk_apb_watchdog_class_init, +}; + +static void cmsdk_apb_watchdog_register_types(void) +{ + type_register_static(&cmsdk_apb_watchdog_info); +} + +type_init(cmsdk_apb_watchdog_register_types); diff --git a/hw/watchdog/trace-events b/hw/watchdog/trace-events new file mode 100644 index 0000000000..fee95847df --- /dev/null +++ b/hw/watchdog/trace-events @@ -0,0 +1,6 @@ +# See docs/devel/tracing.txt for syntax documentation. + +# hw/char/cmsdk_apb_watchdog.c +cmsdk_apb_watchdog_read(uint64_t offset, uint64_t data, unsigned size) "CMSDK APB watchdog read: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u" +cmsdk_apb_watchdog_write(uint64_t offset, uint64_t data, unsigned size) "CMSDK APB watchdog write: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u" +cmsdk_apb_watchdog_reset(void) "CMSDK APB watchdog: reset" diff --git a/include/hw/watchdog/cmsdk-apb-watchdog.h b/include/hw/watchdog/cmsdk-apb-watchdog.h new file mode 100644 index 0000000000..ab8b5987a1 --- /dev/null +++ b/include/hw/watchdog/cmsdk-apb-watchdog.h @@ -0,0 +1,59 @@ +/* + * ARM CMSDK APB watchdog emulation + * + * Copyright (c) 2018 Linaro Limited + * Written by Peter Maydell + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 or + * (at your option) any later version. + */ + +/* + * This is a model of the "APB watchdog" which is part of the Cortex-M + * System Design Kit (CMSDK) and documented in the Cortex-M System + * Design Kit Technical Reference Manual (ARM DDI0479C): + * https://developer.arm.com/products/system-design/system-design-kits/cortex-m-system-design-kit + * + * QEMU interface: + * + QOM property "wdogclk-frq": frequency at which the watchdog is clocked + * + sysbus MMIO region 0: the register bank + * + sysbus IRQ 0: watchdog interrupt + * + * In real hardware the watchdog's reset output is just a GPIO line + * which can then be masked by the board or treated as a simple interrupt. + * (For instance the IoTKit does this with the non-secure watchdog, so that + * secure code can control whether non-secure code can perform a system + * reset via its watchdog.) In QEMU, we just wire up the watchdog reset + * to watchdog_perform_action(), at least for the moment. + */ + +#ifndef CMSDK_APB_WATCHDOG_H +#define CMSDK_APB_WATCHDOG_H + +#include "hw/sysbus.h" +#include "hw/ptimer.h" + +#define TYPE_CMSDK_APB_WATCHDOG "cmsdk-apb-watchdog" +#define CMSDK_APB_WATCHDOG(obj) OBJECT_CHECK(CMSDKAPBWatchdog, (obj), \ + TYPE_CMSDK_APB_WATCHDOG) + +typedef struct CMSDKAPBWatchdog { + /*< private >*/ + SysBusDevice parent_obj; + + /*< public >*/ + MemoryRegion iomem; + qemu_irq wdogint; + uint32_t wdogclk_frq; + struct ptimer_state *timer; + + uint32_t control; + uint32_t intstatus; + uint32_t lock; + uint32_t itcr; + uint32_t itop; + uint32_t resetstatus; +} CMSDKAPBWatchdog; + +#endif |