From b5ff0c6183e0c060725becd6fdb43a08b494fdc1 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 12 Aug 2021 10:33:42 +0100 Subject: hw/arm/stm32f100: Wire up sysclk and refclk Wire up the sysclk and refclk for the stm32f100 SoC. This SoC always runs the systick refclk at 1/8 the frequency of the main CPU clock, so the board code only needs to provide a single sysclk clock. Because there is only one board using this SoC, we convert the SoC and the board together, rather than splitting it into "add clock to SoC; connect clock in board; add error check in SoC code that clock is wired up". When the systick device starts honouring its clock inputs, this will fix an emulation inaccuracy in the stm32vldiscovery board where the systick reference clock was running at 1MHz rather than 3MHz. Signed-off-by: Peter Maydell Reviewed-by: Alistair Francis Reviewed-by: Alexandre Iooss Reviewed-by: Luc Michel Message-id: 20210812093356.1946-12-peter.maydell@linaro.org --- hw/arm/stm32f100_soc.c | 30 ++++++++++++++++++++++++++++++ hw/arm/stm32vldiscovery.c | 12 +++++++----- 2 files changed, 37 insertions(+), 5 deletions(-) (limited to 'hw/arm') diff --git a/hw/arm/stm32f100_soc.c b/hw/arm/stm32f100_soc.c index 0be92b2c47..f7b344ba9f 100644 --- a/hw/arm/stm32f100_soc.c +++ b/hw/arm/stm32f100_soc.c @@ -30,6 +30,7 @@ #include "exec/address-spaces.h" #include "hw/arm/stm32f100_soc.h" #include "hw/qdev-properties.h" +#include "hw/qdev-clock.h" #include "hw/misc/unimp.h" #include "sysemu/sysemu.h" @@ -57,6 +58,9 @@ static void stm32f100_soc_initfn(Object *obj) for (i = 0; i < STM_NUM_SPIS; i++) { object_initialize_child(obj, "spi[*]", &s->spi[i], TYPE_STM32F2XX_SPI); } + + s->sysclk = qdev_init_clock_in(DEVICE(s), "sysclk", NULL, NULL, 0); + s->refclk = qdev_init_clock_in(DEVICE(s), "refclk", NULL, NULL, 0); } static void stm32f100_soc_realize(DeviceState *dev_soc, Error **errp) @@ -68,6 +72,30 @@ static void stm32f100_soc_realize(DeviceState *dev_soc, Error **errp) MemoryRegion *system_memory = get_system_memory(); + /* + * We use s->refclk internally and only define it with qdev_init_clock_in() + * so it is correctly parented and not leaked on an init/deinit; it is not + * intended as an externally exposed clock. + */ + if (clock_has_source(s->refclk)) { + error_setg(errp, "refclk clock must not be wired up by the board code"); + return; + } + + if (!clock_has_source(s->sysclk)) { + error_setg(errp, "sysclk clock must be wired up by the board code"); + return; + } + + /* + * TODO: ideally we should model the SoC RCC and its ability to + * change the sysclk frequency and define different sysclk sources. + */ + + /* The refclk always runs at frequency HCLK / 8 */ + clock_set_mul_div(s->refclk, 8, 1); + clock_set_source(s->refclk, s->sysclk); + /* * Init flash region * Flash starts at 0x08000000 and then is aliased to boot memory at 0x0 @@ -89,6 +117,8 @@ static void stm32f100_soc_realize(DeviceState *dev_soc, Error **errp) qdev_prop_set_uint32(armv7m, "num-irq", 61); qdev_prop_set_string(armv7m, "cpu-type", s->cpu_type); qdev_prop_set_bit(armv7m, "enable-bitband", true); + qdev_connect_clock_in(armv7m, "cpuclk", s->sysclk); + qdev_connect_clock_in(armv7m, "refclk", s->refclk); object_property_set_link(OBJECT(&s->armv7m), "memory", OBJECT(get_system_memory()), &error_abort); if (!sysbus_realize(SYS_BUS_DEVICE(&s->armv7m), errp)) { diff --git a/hw/arm/stm32vldiscovery.c b/hw/arm/stm32vldiscovery.c index 7e8191ebf5..07e401a818 100644 --- a/hw/arm/stm32vldiscovery.c +++ b/hw/arm/stm32vldiscovery.c @@ -27,6 +27,7 @@ #include "qapi/error.h" #include "hw/boards.h" #include "hw/qdev-properties.h" +#include "hw/qdev-clock.h" #include "qemu/error-report.h" #include "hw/arm/stm32f100_soc.h" #include "hw/arm/boot.h" @@ -39,16 +40,17 @@ static void stm32vldiscovery_init(MachineState *machine) { DeviceState *dev; + Clock *sysclk; - /* - * TODO: ideally we would model the SoC RCC and let it handle - * system_clock_scale, including its ability to define different - * possible SYSCLK sources. - */ system_clock_scale = NANOSECONDS_PER_SECOND / SYSCLK_FRQ; + /* This clock doesn't need migration because it is fixed-frequency */ + sysclk = clock_new(OBJECT(machine), "SYSCLK"); + clock_set_hz(sysclk, SYSCLK_FRQ); + dev = qdev_new(TYPE_STM32F100_SOC); qdev_prop_set_string(dev, "cpu-type", ARM_CPU_TYPE_NAME("cortex-m3")); + qdev_connect_clock_in(dev, "sysclk", sysclk); sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal); armv7m_load_kernel(ARM_CPU(first_cpu), -- cgit v1.2.3