Re: [Qemu-devel] [PATCH v1 3/5] hw/misc: Add the STM32F4xx EXTI device

[Alistair Francis <alistair23@gmail.com>]

On Tue, Apr 30, 2019 at 8:48 AM Peter Maydell <peter.maydell@linaro.org> wrote:
>
> On Mon, 29 Apr 2019 at 06:37, Alistair Francis <alistair@alistair23.me> wrote:
> >
> > Signed-off-by: Alistair Francis <alistair@alistair23.me>
> > ---
> >  default-configs/arm-softmmu.mak  |   1 +
> >  hw/misc/Kconfig                  |   3 +
> >  hw/misc/Makefile.objs            |   1 +
> >  hw/misc/stm32f4xx_exti.c         | 175 +++++++++++++++++++++++++++++++
> >  include/hw/misc/stm32f4xx_exti.h |  57 ++++++++++
> >  5 files changed, 237 insertions(+)
> >  create mode 100644 hw/misc/stm32f4xx_exti.c
> >  create mode 100644 include/hw/misc/stm32f4xx_exti.h
>
> Minor comments here only.
>
> (If Thomas's kconfig patchset gets into master before this
> there might be some minor fixups required to the kconfig
> stuff, but it shouldn't be too hard to adapt.)

Yep, I'm happy to rebase on top of his work.

>
> > +#include "qemu/osdep.h"
> > +#include "hw/sysbus.h"
> > +#include "qemu/log.h"
> > +#include "hw/misc/stm32f4xx_exti.h"
> > +
> > +#ifndef STM_EXTI_ERR_DEBUG
> > +#define STM_EXTI_ERR_DEBUG 0
> > +#endif
> > +
> > +#define DB_PRINT_L(lvl, fmt, args...) do { \
> > +    if (STM_EXTI_ERR_DEBUG >= lvl) { \
> > +        qemu_log("%s: " fmt, __func__, ## args); \
> > +    } \
> > +} while (0)
> > +
> > +#define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
>
> Could we use a tracepoint instead?

Yep, fixed in both patches.

>
> > +
> > +#define NUM_GPIO_EVENT_IN_LINES 16
> > +#define NUM_INTERRUPT_OUT_LINES 16
> > +
> > +static void stm32f4xx_exti_reset(DeviceState *dev)
> > +{
> > +    STM32F4xxExtiState *s = STM32F4XX_EXTI(dev);
> > +
> > +    s->exti_imr = 0x00000000;
> > +    s->exti_emr = 0x00000000;
> > +    s->exti_rtsr = 0x00000000;
> > +    s->exti_ftsr = 0x00000000;
> > +    s->exti_swier = 0x00000000;
> > +    s->exti_pr = 0x00000000;
> > +}
> > +
> > +static void stm32f4xx_exti_set_irq(void *opaque, int irq, int level)
> > +{
> > +    STM32F4xxExtiState *s = opaque;
> > +
> > +    DB_PRINT("Set EXTI: %d to %d\n", irq, level);
> > +
> > +    if (level) {
> > +        qemu_irq_pulse(s->irq[irq]);
> > +        s->exti_pr |= 1 << irq;
> > +    }
> > +}
>
> Just to check -- this should definitely be a pulse? I'm always
> a little bit wary of uses of qemu_irq_pulse(), though some
> hardware does pulse IRQ lines rather than holding them until
> dismissed.

The datasheet seems to specify pulse:
"When the selected edge occurs on the event line, an event pulse is generated"

>
> > +static void stm32f4xx_exti_init(Object *obj)
> > +{
> > +    STM32F4xxExtiState *s = STM32F4XX_EXTI(obj);
> > +    int i;
> > +
> > +    s->irq = g_new0(qemu_irq, NUM_INTERRUPT_OUT_LINES);
>
> You could just have the array be inline in the
> STM32F4xxExtiState rather than allocating it separately,
> right?

Yep.

>
> > +    for (i = 0; i < NUM_INTERRUPT_OUT_LINES; i++) {
> > +        sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq[i]);
> > +    }
> > +
> > +    memory_region_init_io(&s->mmio, obj, &stm32f4xx_exti_ops, s,
> > +                          TYPE_STM32F4XX_EXTI, 0x400);
> > +    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
> > +
> > +    qdev_init_gpio_in(DEVICE(obj), stm32f4xx_exti_set_irq,
> > +                      NUM_GPIO_EVENT_IN_LINES);
> > +}
> > +
> > +static void stm32f4xx_exti_class_init(ObjectClass *klass, void *data)
> > +{
> > +    DeviceClass *dc = DEVICE_CLASS(klass);
> > +
> > +    dc->reset = stm32f4xx_exti_reset;
>
> This one's missing vmstate too.

Fixed in both.

Alistair

>
> > +}
> > +
> > +static const TypeInfo stm32f4xx_exti_info = {
> > +    .name          = TYPE_STM32F4XX_EXTI,
> > +    .parent        = TYPE_SYS_BUS_DEVICE,
> > +    .instance_size = sizeof(STM32F4xxExtiState),
> > +    .instance_init = stm32f4xx_exti_init,
> > +    .class_init    = stm32f4xx_exti_class_init,
> > +};
> > +
> > +static void stm32f4xx_exti_register_types(void)
> > +{
> > +    type_register_static(&stm32f4xx_exti_info);
> > +}
> > +
>
> thanks
> -- PMM