From 5c6e1a1cf95f044987fe475560f296b7a4058c58 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 12 Aug 2021 10:33:36 +0100 Subject: [PATCH] hw/timer/armv7m_systick: Add input clocks The v7M systick timer can be programmed to run from either of two clocks: * an "external reference clock" (when SYST_CSR.CLKSOURCE == 0) * the main CPU clock (when SYST_CSR.CLKSOURCE == 1) Our implementation currently hardwires the external reference clock to be 1MHz, and allows boards to set the main CPU clock frequency via the global 'system_clock_scale'. (Most boards set that to a constant value; the Stellaris boards allow the guest to reprogram it via the board-specific RCC registers). As the first step in converting this to use the Clock infrastructure, add input clocks to the systick device for the reference clock and the CPU clock. The device implementation ignores them; once we have made all the users of the device correctly wire up the new Clocks we will switch the implementation to use them and ignore the old system_clock_scale. This is a migration compat break for all M-profile boards, because of the addition of the new clock objects to the vmstate struct. Signed-off-by: Peter Maydell Reviewed-by: Alistair Francis Reviewed-by: Luc Michel Message-id: 20210812093356.1946-6-peter.maydell@linaro.org --- hw/timer/armv7m_systick.c | 10 ++++++++-- include/hw/timer/armv7m_systick.h | 7 +++++++ 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/hw/timer/armv7m_systick.c b/hw/timer/armv7m_systick.c index 2f192011eb..e43f74114e 100644 --- a/hw/timer/armv7m_systick.c +++ b/hw/timer/armv7m_systick.c @@ -14,6 +14,7 @@ #include "migration/vmstate.h" #include "hw/irq.h" #include "hw/sysbus.h" +#include "hw/qdev-clock.h" #include "qemu/timer.h" #include "qemu/log.h" #include "qemu/module.h" @@ -201,6 +202,9 @@ static void systick_instance_init(Object *obj) memory_region_init_io(&s->iomem, obj, &systick_ops, s, "systick", 0xe0); sysbus_init_mmio(sbd, &s->iomem); sysbus_init_irq(sbd, &s->irq); + + s->refclk = qdev_init_clock_in(DEVICE(obj), "refclk", NULL, NULL, 0); + s->cpuclk = qdev_init_clock_in(DEVICE(obj), "cpuclk", NULL, NULL, 0); } static void systick_realize(DeviceState *dev, Error **errp) @@ -215,9 +219,11 @@ static void systick_realize(DeviceState *dev, Error **errp) static const VMStateDescription vmstate_systick = { .name = "armv7m_systick", - .version_id = 2, - .minimum_version_id = 2, + .version_id = 3, + .minimum_version_id = 3, .fields = (VMStateField[]) { + VMSTATE_CLOCK(refclk, SysTickState), + VMSTATE_CLOCK(cpuclk, SysTickState), VMSTATE_UINT32(control, SysTickState), VMSTATE_INT64(tick, SysTickState), VMSTATE_PTIMER(ptimer, SysTickState), diff --git a/include/hw/timer/armv7m_systick.h b/include/hw/timer/armv7m_systick.h index 685fc5bc0d..38adf8d274 100644 --- a/include/hw/timer/armv7m_systick.h +++ b/include/hw/timer/armv7m_systick.h @@ -15,6 +15,7 @@ #include "hw/sysbus.h" #include "qom/object.h" #include "hw/ptimer.h" +#include "hw/clock.h" #define TYPE_SYSTICK "armv7m_systick" @@ -25,6 +26,10 @@ OBJECT_DECLARE_SIMPLE_TYPE(SysTickState, SYSTICK) * + sysbus MMIO region 0 is the register interface (covering * the registers which are mapped at address 0xE000E010) * + sysbus IRQ 0 is the interrupt line to the NVIC + * + Clock input "refclk" is the external reference clock + * (used when SYST_CSR.CLKSOURCE == 0) + * + Clock input "cpuclk" is the main CPU clock + * (used when SYST_CSR.CLKSOURCE == 1) */ struct SysTickState { @@ -38,6 +43,8 @@ struct SysTickState { ptimer_state *ptimer; MemoryRegion iomem; qemu_irq irq; + Clock *refclk; + Clock *cpuclk; }; /*