Re: [Qemu-devel] [PATCH 09/13] mxs/imx23: Add the RTC block

[Peter Crosthwaite]

On Wed, Dec 11, 2013 at 11:56 PM, Michel Pollet <address@hidden> wrote:
> Support for the RTC IO block on the imx23, enough to return
> a valid date and make guest linux happy.
>
> Signed-off-by: Michel Pollet <address@hidden>
> ---
>  hw/timer/Makefile.objs |   1 +
>  hw/timer/mxs_rtc.c     | 147 
> +++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 148 insertions(+)
>  create mode 100644 hw/timer/mxs_rtc.c
>
> diff --git a/hw/timer/Makefile.objs b/hw/timer/Makefile.objs
> index 3ae091c..1003169 100644
> --- a/hw/timer/Makefile.objs
> +++ b/hw/timer/Makefile.objs
> @@ -26,5 +26,6 @@ obj-$(CONFIG_OMAP) += omap_synctimer.o
>  obj-$(CONFIG_PXA2XX) += pxa2xx_timer.o
>  obj-$(CONFIG_SH4) += sh_timer.o
>  obj-$(CONFIG_TUSB6010) += tusb6010.o
> +obj-$(CONFIG_MXS) += mxs_rtc.o
>
>  obj-$(CONFIG_MC146818RTC) += mc146818rtc.o
> diff --git a/hw/timer/mxs_rtc.c b/hw/timer/mxs_rtc.c
> new file mode 100644
> index 0000000..628fade
> --- /dev/null
> +++ b/hw/timer/mxs_rtc.c
> @@ -0,0 +1,147 @@
> +/*
> + * mxs_rtc.c
> + *
> + * Copyright: Michel Pollet <address@hidden>
> + *
> + * QEMU Licence
> + */
> +/*
> + * Implement the RTC block of the mxs. At least, the real time stuff.
> + * TODO Alarm, and watchdog ?
> + */
> +
> +#include "hw/sysbus.h"
> +#include "hw/arm/mxs.h"
> +
> +#define D(w)
> +
> +enum {
> +    RTC_CTRL = 0x0,
> +    RTC_STAT = 0x1,
> +    RTC_MS = 0x2,
> +    RTC_SECONDS = 0x3,
> +    RTC_ALARM = 0x4,
> +    RTC_WATCHDOG = 0x5,
> +    RTC_PERSISTENT0 = 0x6,
> +    RTC_PERSISTENT1 = 0x7,
> +    RTC_PERSISTENT2 = 0x8,
> +    RTC_PERSISTENT3 = 0x9,
> +    RTC_PERSISTENT4 = 0xa,
> +    RTC_PERSISTENT5 = 0xa,
> +    RTC_DEBUG = 0xc,
> +    RTC_VERSION = 0xd,
> +
> +    RTC_MAX,
> +};
> +typedef struct mxs_rtc_state {
> +    SysBusDevice busdev;
> +    MemoryRegion iomem;
> +    uint32_t base_ms, base_s;
> +    uint32_t r[RTC_MAX];
> +    qemu_irq alarm_irq;
> +    CharDriverState *chr;
> +} mxs_rtc_state;
> +
> +static uint64_t mxs_rtc_read(
> +        void *opaque, hwaddr offset, unsigned size)
> +{
> +    mxs_rtc_state *s = (mxs_rtc_state *) opaque;
> +    uint32_t res = 0;
> +
> +    D(printf("%s %04x (%d) = ", __func__, (int)offset, size);)
> +    switch (offset >> 4) {
> +        case 0 ... RTC_MAX:
> +            if ((offset >> 4) == RTC_MS || (offset >> 4) == RTC_SECONDS) {
> +                struct timeval tv;
> +                gettimeofday(&tv, NULL);
> +                s->r[RTC_MS] = (tv.tv_usec / 1000) - s->base_ms;
> +                s->r[RTC_SECONDS] = tv.tv_sec - s->base_s;
> +            }
> +            res = s->r[offset >> 4];
> +            break;
> +        default:
> +            qemu_log_mask(LOG_GUEST_ERROR,
> +                    "%s: bad offset 0x%x\n", __func__, (int) offset);
> +            break;

So for these peripherals that are just a straight up register set of
R_MAX, can you define the MMIO region as R_MAX*4 rather than 0x2000?
Then you can drop these log_guest_errors that are trying to trap
accesses outside the peripheral. Whats the architectural significance
of 0x2000?

Regards,
Peter

> +    }
> +    D(printf("%08x\n", res);)
> +
> +    return res;
> +}
> +
> +static void mxs_rtc_write(void *opaque, hwaddr offset,
> +        uint64_t value, unsigned size)
> +{
> +    mxs_rtc_state *s = (mxs_rtc_state *) opaque;
> +    uint32_t oldvalue = 0;
> +
> +    D(printf("%s %04x %08x(%d)\n", __func__, (int)offset, (int)value, size);)
> +    switch (offset >> 4) {
> +        case 0 ... RTC_MAX:
> +            mxs_write(&s->r[offset >> 4], offset, value, size);
> +            break;
> +        default:
> +            qemu_log_mask(LOG_GUEST_ERROR,
> +                    "%s: bad offset 0x%x\n", __func__, (int) offset);
> +            break;
> +    }
> +    switch (offset >> 4) {
> +        case RTC_MS:
> +            s->base_ms = s->r[RTC_MS];
> +            break;
> +        case RTC_SECONDS:
> +            s->base_s = s->r[RTC_SECONDS];
> +            break;
> +        case RTC_CTRL:
> +            if ((oldvalue ^ s->r[RTC_CTRL]) == 0x80000000
> +                    && !(oldvalue & 0x80000000)) {
> +                D(printf("%s reseting, anding clockgate\n", __func__);)
> +                s->r[RTC_CTRL] |= 0x40000000;
> +            }
> +            break;
> +    }
> +}
> +
> +static const MemoryRegionOps mxs_rtc_ops = {
> +    .read = mxs_rtc_read,
> +    .write = mxs_rtc_write,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +};
> +
> +static int mxs_rtc_init(SysBusDevice *dev)
> +{
> +    mxs_rtc_state *s = OBJECT_CHECK(mxs_rtc_state, dev, "mxs_rtc");
> +
> +    sysbus_init_irq(dev, &s->alarm_irq);
> +    memory_region_init_io(&s->iomem, OBJECT(s), &mxs_rtc_ops, s,
> +            "mxs_rtc", 0x2000);
> +    sysbus_init_mmio(dev, &s->iomem);
> +
> +    s->r[RTC_CTRL] = 0xc0000000;
> +    s->r[RTC_STAT] = 0xe80f0000;
> +    s->r[RTC_VERSION] = 0x02000000;
> + //   s->base_s = time(NULL);
> +    return 0;
> +}
> +
> +
> +static void mxs_rtc_class_init(ObjectClass *klass, void *data)
> +{
> +    SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
> +
> +    sdc->init = mxs_rtc_init;
> +}
> +
> +static TypeInfo rtc_info = {
> +    .name          = "mxs_rtc",
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(mxs_rtc_state),
> +    .class_init    = mxs_rtc_class_init,
> +};
> +
> +static void mxs_rtc_register(void)
> +{
> +    type_register_static(&rtc_info);
> +}
> +
> +type_init(mxs_rtc_register)
> --
> 1.8.5.1
>
>