Re: [Qemu-devel] [PATCH v10 1/5] stm32f2xx_timer: Add the stm32f2xx Timer

[Peter Crosthwaite <peter.crosthwaite@xilinx.com>]

On Thu, Jan 29, 2015 at 4:31 AM, Alistair Francis <alistair23@gmail.com> wrote:
> This patch adds the stm32f2xx timers: TIM2, TIM3, TIM4 and TIM5
> to QEMU.
>
> Signed-off-by: Alistair Francis <alistair@alistair23.me>
> Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
> ---
> V10:
>  - Correct the units based on a patch by Peter C
> V9:
>  - Convert tick_offset to now be updated on more events
>     - This is similar to what I did with the ARM PCCNT regiseter
> V8:
>  - Fix tick_offset to allow now to wrap around
>  - Remove the calls to get_ticks_per_sec()
>  - Pre-scale the guest visable time
> V6:
>  - Rename to STM32F2XX
>  - Change the timer calculations to use ns
>  - Update the value to timer_mod to ensure it is in ns
>  - Account for reloadable/resetable timer
>     - Thanks to Peter C for pointing this out
>
>  default-configs/arm-softmmu.mak    |   1 +
>  hw/timer/Makefile.objs             |   2 +
>  hw/timer/stm32f2xx_timer.c         | 324 +++++++++++++++++++++++++++++++++++++
>  include/hw/timer/stm32f2xx_timer.h | 101 ++++++++++++
>  4 files changed, 428 insertions(+)
>  create mode 100644 hw/timer/stm32f2xx_timer.c
>  create mode 100644 include/hw/timer/stm32f2xx_timer.h
>
> diff --git a/default-configs/arm-softmmu.mak b/default-configs/arm-softmmu.mak
> index f3513fa..faea100 100644
> --- a/default-configs/arm-softmmu.mak
> +++ b/default-configs/arm-softmmu.mak
> @@ -78,6 +78,7 @@ CONFIG_NSERIES=y
>  CONFIG_REALVIEW=y
>  CONFIG_ZAURUS=y
>  CONFIG_ZYNQ=y
> +CONFIG_STM32F2XX_TIMER=y
>
>  CONFIG_VERSATILE_PCI=y
>  CONFIG_VERSATILE_I2C=y
> diff --git a/hw/timer/Makefile.objs b/hw/timer/Makefile.objs
> index 2c86c3d..133bd0d 100644
> --- a/hw/timer/Makefile.objs
> +++ b/hw/timer/Makefile.objs
> @@ -31,3 +31,5 @@ obj-$(CONFIG_DIGIC) += digic-timer.o
>  obj-$(CONFIG_MC146818RTC) += mc146818rtc.o
>
>  obj-$(CONFIG_ALLWINNER_A10_PIT) += allwinner-a10-pit.o
> +
> +common-obj-$(CONFIG_STM32F2XX_TIMER) += stm32f2xx_timer.o
> diff --git a/hw/timer/stm32f2xx_timer.c b/hw/timer/stm32f2xx_timer.c
> new file mode 100644
> index 0000000..72de746
> --- /dev/null
> +++ b/hw/timer/stm32f2xx_timer.c
> @@ -0,0 +1,324 @@
> +/*
> + * STM32F2XX Timer
> + *
> + * Copyright (c) 2014 Alistair Francis <alistair@alistair23.me>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#include "hw/timer/stm32f2xx_timer.h"
> +
> +#ifndef STM_TIMER_ERR_DEBUG
> +#define STM_TIMER_ERR_DEBUG 0
> +#endif
> +
> +#define DB_PRINT_L(lvl, fmt, args...) do { \
> +    if (STM_TIMER_ERR_DEBUG >= lvl) { \
> +        qemu_log("%s: " fmt, __func__, ## args); \
> +    } \
> +} while (0);
> +
> +#define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
> +
> +static void stm32f2xx_timer_set_alarm(STM32F2XXTimerState *s, int64_t now);
> +
> +static void stm32f2xx_timer_interrupt(void *opaque)
> +{
> +    STM32F2XXTimerState *s = opaque;
> +
> +    DB_PRINT("Interrupt\n");
> +
> +    if (s->tim_dier & TIM_DIER_UIE && s->tim_cr1 & TIM_CR1_CEN) {
> +        s->tim_sr |= 1;
> +        qemu_irq_pulse(s->irq);
> +        stm32f2xx_timer_set_alarm(s, s->hit_time);
> +    }
> +}
> +
> +static inline int64_t stm32f2xx_ns_to_ticks(STM32F2XXTimerState *s, int64_t t)
> +{
> +    return muldiv64(t, s->freq_hz, 1000000000ULL) / (s->tim_psc + 1);
> +}
> +
> +static void stm32f2xx_timer_set_alarm(STM32F2XXTimerState *s, int64_t now)
> +{
> +    uint64_t ticks;
> +    int64_t now_ticks;
> +
> +    if (s->tim_arr == 0) {
> +        return;
> +    }
> +
> +    DB_PRINT("Alarm set at: 0x%x\n", s->tim_cr1);
> +
> +    now_ticks = stm32f2xx_ns_to_ticks(s, now);
> +    ticks = s->tim_arr - (now_ticks - s->tick_offset);
> +
> +    DB_PRINT("Alarm set in %d ticks\n", (int) ticks);
> +
> +    s->hit_time = muldiv64((ticks + (uint64_t) now_ticks) * (s->tim_psc + 1),
> +                               1000000000ULL, s->freq_hz);
> +
> +    timer_mod(s->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->hit_time);
> +    DB_PRINT("Wait Time: %" PRId64 " ticks\n", s->hit_time);
> +}
> +
> +static void stm32f2xx_timer_reset(DeviceState *dev)
> +{
> +    STM32F2XXTimerState *s = STM32F2XXTIMER(dev);
> +    int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> +
> +    s->tim_cr1 = 0;
> +    s->tim_cr2 = 0;
> +    s->tim_smcr = 0;
> +    s->tim_dier = 0;
> +    s->tim_sr = 0;
> +    s->tim_egr = 0;
> +    s->tim_ccmr1 = 0;
> +    s->tim_ccmr2 = 0;
> +    s->tim_ccer = 0;
> +    s->tim_psc = 0;
> +    s->tim_arr = 0;
> +    s->tim_ccr1 = 0;
> +    s->tim_ccr2 = 0;
> +    s->tim_ccr3 = 0;
> +    s->tim_ccr4 = 0;
> +    s->tim_dcr = 0;
> +    s->tim_dmar = 0;
> +    s->tim_or = 0;
> +
> +    s->tick_offset = stm32f2xx_ns_to_ticks(s, now);
> +}
> +
> +static uint64_t stm32f2xx_timer_read(void *opaque, hwaddr offset,
> +                           unsigned size)
> +{
> +    STM32F2XXTimerState *s = opaque;
> +
> +    DB_PRINT("Read 0x%"HWADDR_PRIx"\n", offset);
> +
> +    switch (offset) {
> +    case TIM_CR1:
> +        return s->tim_cr1;
> +    case TIM_CR2:
> +        return s->tim_cr2;
> +    case TIM_SMCR:
> +        return s->tim_smcr;
> +    case TIM_DIER:
> +        return s->tim_dier;
> +    case TIM_SR:
> +        return s->tim_sr;
> +    case TIM_EGR:
> +        return s->tim_egr;
> +    case TIM_CCMR1:
> +        return s->tim_ccmr1;
> +    case TIM_CCMR2:
> +        return s->tim_ccmr2;
> +    case TIM_CCER:
> +        return s->tim_ccer;
> +    case TIM_CNT:
> +        return stm32f2xx_ns_to_ticks(s, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)) -
> +               s->tick_offset;
> +    case TIM_PSC:
> +        return s->tim_psc;
> +    case TIM_ARR:
> +        return s->tim_arr;
> +    case TIM_CCR1:
> +        return s->tim_ccr1;
> +    case TIM_CCR2:
> +        return s->tim_ccr2;
> +    case TIM_CCR3:
> +        return s->tim_ccr3;
> +    case TIM_CCR4:
> +        return s->tim_ccr4;
> +    case TIM_DCR:
> +        return s->tim_dcr;
> +    case TIM_DMAR:
> +        return s->tim_dmar;
> +    case TIM_OR:
> +        return s->tim_or;
> +    default:
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, offset);
> +    }
> +
> +    return 0;
> +}
> +
> +static void stm32f2xx_timer_write(void *opaque, hwaddr offset,
> +                        uint64_t val64, unsigned size)
> +{
> +    STM32F2XXTimerState *s = opaque;
> +    uint32_t value = val64;
> +    int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> +    uint32_t timer_val = 0;
> +
> +    DB_PRINT("Write 0x%x, 0x%"HWADDR_PRIx"\n", value, offset);
> +
> +    switch (offset) {
> +    case TIM_CR1:
> +        s->tim_cr1 = value;
> +        return;
> +    case TIM_CR2:
> +        s->tim_cr2 = value;
> +        return;
> +    case TIM_SMCR:
> +        s->tim_smcr = value;
> +        return;
> +    case TIM_DIER:
> +        s->tim_dier = value;
> +        return;
> +    case TIM_SR:
> +        /* This is set by hardware and cleared by software */
> +        s->tim_sr &= value;
> +        return;
> +    case TIM_EGR:
> +        s->tim_egr = value;
> +        if (s->tim_egr & TIM_EGR_UG) {
> +            timer_val = 0;
> +            break;
> +        }
> +        return;
> +    case TIM_CCMR1:
> +        s->tim_ccmr1 = value;
> +        return;
> +    case TIM_CCMR2:
> +        s->tim_ccmr2 = value;
> +        return;
> +    case TIM_CCER:
> +        s->tim_ccer = value;
> +        return;
> +    case TIM_PSC:
> +        timer_val = stm32f2xx_ns_to_ticks(s, now) - s->tick_offset;
> +        s->tim_psc = value;
> +        value = timer_val;
> +        break;
> +    case TIM_CNT:
> +        timer_val = value;
> +        break;
> +    case TIM_ARR:
> +        s->tim_arr = value;
> +        stm32f2xx_timer_set_alarm(s, now);
> +        return;
> +    case TIM_CCR1:
> +        s->tim_ccr1 = value;
> +        return;
> +    case TIM_CCR2:
> +        s->tim_ccr2 = value;
> +        return;
> +    case TIM_CCR3:
> +        s->tim_ccr3 = value;
> +        return;
> +    case TIM_CCR4:
> +        s->tim_ccr4 = value;
> +        return;
> +    case TIM_DCR:
> +        s->tim_dcr = value;
> +        return;
> +    case TIM_DMAR:
> +        s->tim_dmar = value;
> +        return;
> +    case TIM_OR:
> +        s->tim_or = value;
> +        return;
> +    default:
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, offset);

return;

> +    }

The flow control is a little tricky here and deserves a comment.

"If we get here, a register write has affected the timer in a way that
requires a refresh of both tick_offset and the alarm".

Otherwise

Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

Regards,
Peter

> +
> +    s->tick_offset = stm32f2xx_ns_to_ticks(s, now) - timer_val;
> +    stm32f2xx_timer_set_alarm(s, now);
> +}
> +
> +static const MemoryRegionOps stm32f2xx_timer_ops = {
> +    .read = stm32f2xx_timer_read,
> +    .write = stm32f2xx_timer_write,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +};
> +
> +static const VMStateDescription vmstate_stm32f2xx_timer = {
> +    .name = TYPE_STM32F2XX_TIMER,
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_INT64(tick_offset, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_cr1, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_cr2, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_smcr, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_dier, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_sr, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_egr, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_ccmr1, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_ccmr2, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_ccer, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_psc, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_arr, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_ccr1, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_ccr2, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_ccr3, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_ccr4, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_dcr, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_dmar, STM32F2XXTimerState),
> +        VMSTATE_UINT32(tim_or, STM32F2XXTimerState),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
> +static Property stm32f2xx_timer_properties[] = {
> +    DEFINE_PROP_UINT64("clock-frequency", struct STM32F2XXTimerState,
> +                       freq_hz, 1000000000),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void stm32f2xx_timer_init(Object *obj)
> +{
> +    STM32F2XXTimerState *s = STM32F2XXTIMER(obj);
> +
> +    sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq);
> +
> +    memory_region_init_io(&s->iomem, obj, &stm32f2xx_timer_ops, s,
> +                          "stm32f2xx_timer", 0x4000);
> +    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem);
> +
> +    s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, stm32f2xx_timer_interrupt, s);
> +}
> +
> +static void stm32f2xx_timer_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +
> +    dc->reset = stm32f2xx_timer_reset;
> +    dc->props = stm32f2xx_timer_properties;
> +    dc->vmsd = &vmstate_stm32f2xx_timer;
> +}
> +
> +static const TypeInfo stm32f2xx_timer_info = {
> +    .name          = TYPE_STM32F2XX_TIMER,
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(STM32F2XXTimerState),
> +    .instance_init = stm32f2xx_timer_init,
> +    .class_init    = stm32f2xx_timer_class_init,
> +};
> +
> +static void stm32f2xx_timer_register_types(void)
> +{
> +    type_register_static(&stm32f2xx_timer_info);
> +}
> +
> +type_init(stm32f2xx_timer_register_types)
> diff --git a/include/hw/timer/stm32f2xx_timer.h b/include/hw/timer/stm32f2xx_timer.h
> new file mode 100644
> index 0000000..7362d70
> --- /dev/null
> +++ b/include/hw/timer/stm32f2xx_timer.h
> @@ -0,0 +1,101 @@
> +/*
> + * STM32F2XX Timer
> + *
> + * Copyright (c) 2014 Alistair Francis <alistair@alistair23.me>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#ifndef HW_STM_TIMER_H
> +#define HW_STM_TIMER_H
> +
> +#include "hw/sysbus.h"
> +#include "qemu/timer.h"
> +#include "sysemu/sysemu.h"
> +
> +#define TIM_CR1      0x00
> +#define TIM_CR2      0x04
> +#define TIM_SMCR     0x08
> +#define TIM_DIER     0x0C
> +#define TIM_SR       0x10
> +#define TIM_EGR      0x14
> +#define TIM_CCMR1    0x18
> +#define TIM_CCMR2    0x1C
> +#define TIM_CCER     0x20
> +#define TIM_CNT      0x24
> +#define TIM_PSC      0x28
> +#define TIM_ARR      0x2C
> +#define TIM_CCR1     0x34
> +#define TIM_CCR2     0x38
> +#define TIM_CCR3     0x3C
> +#define TIM_CCR4     0x40
> +#define TIM_DCR      0x48
> +#define TIM_DMAR     0x4C
> +#define TIM_OR       0x50
> +
> +#define TIM_CR1_CEN   1
> +
> +#define TIM_EGR_UG 1
> +
> +#define TIM_CCER_CC2E   (1 << 4)
> +#define TIM_CCMR1_OC2M2 (1 << 14)
> +#define TIM_CCMR1_OC2M1 (1 << 13)
> +#define TIM_CCMR1_OC2M0 (1 << 12)
> +#define TIM_CCMR1_OC2PE (1 << 11)
> +
> +#define TIM_DIER_UIE  1
> +
> +#define TYPE_STM32F2XX_TIMER "stm32f2xx-timer"
> +#define STM32F2XXTIMER(obj) OBJECT_CHECK(STM32F2XXTimerState, \
> +                            (obj), TYPE_STM32F2XX_TIMER)
> +
> +typedef struct STM32F2XXTimerState {
> +    /* <private> */
> +    SysBusDevice parent_obj;
> +
> +    /* <public> */
> +    MemoryRegion iomem;
> +    QEMUTimer *timer;
> +    qemu_irq irq;
> +
> +    int64_t tick_offset;
> +    uint64_t hit_time;
> +    uint64_t freq_hz;
> +
> +    uint32_t tim_cr1;
> +    uint32_t tim_cr2;
> +    uint32_t tim_smcr;
> +    uint32_t tim_dier;
> +    uint32_t tim_sr;
> +    uint32_t tim_egr;
> +    uint32_t tim_ccmr1;
> +    uint32_t tim_ccmr2;
> +    uint32_t tim_ccer;
> +    uint32_t tim_psc;
> +    uint32_t tim_arr;
> +    uint32_t tim_ccr1;
> +    uint32_t tim_ccr2;
> +    uint32_t tim_ccr3;
> +    uint32_t tim_ccr4;
> +    uint32_t tim_dcr;
> +    uint32_t tim_dmar;
> +    uint32_t tim_or;
> +} STM32F2XXTimerState;
> +
> +#endif
> --
> 2.1.0
>
>