Re: [Qemu-devel] [RFC v3 3/5] hw/arm/digic: add timer support

[Antony Pavlov]

On Wed, 4 Sep 2013 16:18:37 +1000
Peter Crosthwaite <address@hidden> wrote:

> On Wed, Sep 4, 2013 at 3:21 PM, Antony Pavlov <address@hidden> wrote:
> > Signed-off-by: Antony Pavlov <address@hidden>
> > ---
> >  hw/arm/digic.c         |  25 ++++++++++
> >  hw/timer/Makefile.objs |   1 +
> >  hw/timer/digic-timer.c | 122 
> > +++++++++++++++++++++++++++++++++++++++++++++++++
> >  hw/timer/digic-timer.h |  19 ++++++++
> >  include/hw/arm/digic.h |   7 +++
> >  5 files changed, 174 insertions(+)
> >  create mode 100644 hw/timer/digic-timer.c
> >  create mode 100644 hw/timer/digic-timer.h
> >
> > diff --git a/hw/arm/digic.c b/hw/arm/digic.c
> > index 95a9fcd..a71364b 100644
> > --- a/hw/arm/digic.c
> > +++ b/hw/arm/digic.c
> > @@ -30,21 +30,46 @@
> >  static void digic_init(Object *obj)
> >  {
> >      DigicState *s = DIGIC(obj);
> > +    DeviceState *dev;
> > +    int i;
> >
> >      object_initialize(&s->cpu, sizeof(s->cpu), "arm946-" TYPE_ARM_CPU);
> >      object_property_add_child(obj, "cpu", OBJECT(&s->cpu), NULL);
> > +
> > +    for (i = 0; i < DIGIC4_NB_TIMERS; i++) {
> > +        char name[9];
> > +
> 
> Bit of a trap if theres every more than 10 timers as the name string
> will run off the end if %d is below with 10. Its ok to round up a
> little just for defensiveness.
> 
> > +        object_initialize(&s->timer[i], sizeof(s->timer[i]), 
> > TYPE_DIGIC_TIMER);
> > +        dev = DEVICE(&s->timer[i]);
> > +        qdev_set_parent_bus(dev, sysbus_get_default());
> > +        snprintf(name, 9, "timer[%d]", i);
> > +        object_property_add_child(obj, name, OBJECT(&s->timer[i]), NULL);
> > +    }
> >  }
> >
> >  static void digic_realize(DeviceState *dev, Error **errp)
> >  {
> >      DigicState *s = DIGIC(dev);
> >      Error *err = NULL;
> > +    SysBusDevice *sbd;
> > +    int i;
> >
> >      object_property_set_bool(OBJECT(&s->cpu), true, "realized", &err);
> >      if (err != NULL) {
> >          error_propagate(errp, err);
> >          return;
> >      }
> > +
> > +    for (i = 0; i < DIGIC4_NB_TIMERS; i++) {
> > +        object_property_set_bool(OBJECT(&s->timer[i]), true, "realized", 
> > &err);
> > +        if (err != NULL) {
> > +            error_propagate(errp, err);
> > +            return;
> > +        }
> > +
> > +        sbd = SYS_BUS_DEVICE(&s->timer[i]);
> > +        sysbus_mmio_map(sbd, 0, DIGIC4_TIMER_BASE(i));
> > +    }
> >  }
> >
> >  static void digic_class_init(ObjectClass *oc, void *data)
> > diff --git a/hw/timer/Makefile.objs b/hw/timer/Makefile.objs
> > index eca5905..5479aee 100644
> > --- a/hw/timer/Makefile.objs
> > +++ b/hw/timer/Makefile.objs
> > @@ -25,5 +25,6 @@ obj-$(CONFIG_OMAP) += omap_synctimer.o
> >  obj-$(CONFIG_PXA2XX) += pxa2xx_timer.o
> >  obj-$(CONFIG_SH4) += sh_timer.o
> >  obj-$(CONFIG_TUSB6010) += tusb6010.o
> > +obj-$(CONFIG_DIGIC) += digic-timer.o
> >
> >  obj-$(CONFIG_MC146818RTC) += mc146818rtc.o
> > diff --git a/hw/timer/digic-timer.c b/hw/timer/digic-timer.c
> > new file mode 100644
> > index 0000000..c6cf7ee
> > --- /dev/null
> > +++ b/hw/timer/digic-timer.c
> > @@ -0,0 +1,122 @@
> > +/*
> > + * QEMU model of the Canon Digic timer block.
> > + *
> > + * Copyright (C) 2013 Antony Pavlov <address@hidden>
> > + *
> > + * This model is based on reverse engineering efforts
> > + * made by CHDK (http://chdk.wikia.com) and
> > + * Magic Lantern (http://www.magiclantern.fm) projects
> > + * contributors.
> > + *
> > + * See "Timer/Clock Module" docs here:
> > + *   http://magiclantern.wikia.com/wiki/Register_Map
> > + *
> > + * The QEMU model of the OSTimer in PKUnity SoC by Guan Xuetao
> > + * is used as a template.
> > + *
> > + * This library is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU Lesser General Public
> > + * License as published by the Free Software Foundation; either
> > + * version 2 of the License, or (at your option) any later version.
> > + *
> > + * This library is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > + * Lesser General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU Lesser General Public
> > + * License along with this library; if not, see 
> > <http://www.gnu.org/licenses/>.
> > + *
> > + */
> > +
> > +#include "hw/sysbus.h"
> > +#include "hw/ptimer.h"
> > +#include "qemu/main-loop.h"
> > +
> > +#include "hw/timer/digic-timer.h"
> > +
> > +#ifdef DEBUG_DIGIC_TIMER
> > +#define DPRINTF(fmt, ...) printf("%s: " fmt , __func__, ## __VA_ARGS__)
> > +#else
> > +#define DPRINTF(fmt, ...) do {} while (0)
> > +#endif
> 
> I think we were encouraging unconditional compilation of error printfs
> rather than stripping them. This means bugs in maybe change patterns
> involving types which affect debug printfs can be caught in developer
> compile testing.

  Yes, barebox project have same the same tendency. 

> Something like this would work, although Andreas played with this
> recently and may have more convincing ideas.
> 
> #ifndef XILINX_SPIPS_ERR_DEBUG
> #define XILINX_SPIPS_ERR_DEBUG 0
> #endif
> 
> #define DB_PRINT_L(level, ...) do { \
>     if (XILINX_SPIPS_ERR_DEBUG > (level)) { \
>         fprintf(stderr,  ": %s: ", __func__); \
>         fprintf(stderr, ## __VA_ARGS__); \
>     } \
> } while (0);

  Do we really need a preprocessor macro here?
  IMHO we can use a static inline function.

> > +
> > +# define DIGIC_TIMER_CONTROL 0x00
> > +# define DIGIC_TIMER_VALUE 0x0c
> > +
> > +static uint64_t digic_timer_read(void *opaque, hwaddr offset,
> > +        unsigned size)
> > +{
> > +    DigicTimerState *s = opaque;
> > +    uint32_t ret = 0;
> > +
> > +    switch (offset) {
> > +    case DIGIC_TIMER_VALUE:
> > +        ret = (uint32_t)ptimer_get_count(s->ptimer);
> > +        ret = ret & 0xffff;
> > +        break;
> > +    default:
> > +        DPRINTF("Bad offset %x\n", (int)offset);
> 
> Guest error or Unimp?
> 
> > +    }
> > +
> > +    DPRINTF("offset 0x%x, value 0x%x\n", offset, ret);
> > +    return ret;
> > +}
> > +
> > +static void digic_timer_write(void *opaque, hwaddr offset,
> > +        uint64_t value, unsigned size)
> > +{
> > +    DigicTimerState *s = opaque;
> > +
> > +    /* FIXME: just now we ignore timer enable bit */
> > +    ptimer_set_limit(s->ptimer, 0x0000ffff, 1);
> > +    ptimer_run(s->ptimer, 1);
> > +}
> > +
> > +static const MemoryRegionOps digic_timer_ops = {
> > +    .read = digic_timer_read,
> > +    .write = digic_timer_write,
> > +    .impl = {
> > +        .min_access_size = 4,
> > +        .max_access_size = 4,
> > +    },
> > +    .endianness = DEVICE_NATIVE_ENDIAN,
> > +};
> > +
> > +static void digic_timer_tick(void *opaque)
> > +{
> > +    DigicTimerState *s = opaque;
> > +
> > +    ptimer_run(s->ptimer, 1);
> > +}
> > +
> > +static void digic_timer_init(Object *obj)
> > +{
> > +    DigicTimerState *s = DIGIC_TIMER(obj);
> > +
> > +    s->bh = qemu_bh_new(digic_timer_tick, s);
> > +    s->ptimer = ptimer_init(s->bh);
> > +
> > +    /* FIXME: there is no documentation on Digic timer
> > +     * frequency setup so let's it always run on 1 MHz
> 
> "let" (no "'s"). s/on/at
> 
> > +     * */
> 
> Extra * unneeded.
> 
> > +    ptimer_set_freq(s->ptimer, 1 * 1000 * 1000);
> > +
> > +    memory_region_init_io(&s->iomem, OBJECT(s), &digic_timer_ops, s,
> > +            TYPE_DIGIC_TIMER, 0x100);
> 
> Line continued function patameters should line up just past the
> opening ( on the next line:
> 
> function(foo,
>          bar
> 
> > +    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem);
> > +}
> > +
> > +static const TypeInfo digic_timer_info = {
> > +    .name = TYPE_DIGIC_TIMER,
> > +    .parent = TYPE_SYS_BUS_DEVICE,
> > +    .instance_size = sizeof(DigicTimerState),
> > +    .instance_init = digic_timer_init,
> > +};
> > +
> > +static void digic_timer_register_type(void)
> > +{
> > +    type_register_static(&digic_timer_info);
> > +}
> > +
> > +type_init(digic_timer_register_type)
> > diff --git a/hw/timer/digic-timer.h b/hw/timer/digic-timer.h
> > new file mode 100644
> > index 0000000..6483516
> > --- /dev/null
> > +++ b/hw/timer/digic-timer.h
> > @@ -0,0 +1,19 @@
> > +#ifndef HW_TIMER_DIGIC_TIMER_H
> > +#define HW_TIMER_DIGIC_TIMER_H
> > +
> > +#include "hw/sysbus.h"
> > +#include "qemu/typedefs.h"
> > +#include "hw/ptimer.h"
> > +
> > +#define TYPE_DIGIC_TIMER "digic-timer"
> > +#define DIGIC_TIMER(obj) OBJECT_CHECK(DigicTimerState, (obj), 
> > TYPE_DIGIC_TIMER)
> > +
> > +typedef struct DigicTimerState {
> > +    SysBusDevice parent_obj;
> > +
> > +    MemoryRegion iomem;
> > +    QEMUBH *bh;
> > +    ptimer_state *ptimer;
> > +} DigicTimerState;
> > +
> > +#endif /* HW_TIMER_DIGIC_TIMER_H */
> > diff --git a/include/hw/arm/digic.h b/include/hw/arm/digic.h
> > index 0ef4723..472d7d7 100644
> > --- a/include/hw/arm/digic.h
> > +++ b/include/hw/arm/digic.h
> > @@ -10,6 +10,11 @@
> >
> >  #include "cpu-qom.h"
> >
> > +#include "hw/timer/digic-timer.h"
> > +
> > +#define DIGIC4_NB_TIMERS 3
> > +#define DIGIC4_TIMER_BASE(n)    (0xc0210000 + n * 0x100)
> 
> (n) in its usage to guard against order of operations confusion incase
> macro is ever used with an arithmetic expression.
> 
> > +
> >  #define TYPE_DIGIC "digic"
> >
> >  #define DIGIC(obj) OBJECT_CHECK(DigicState, (obj), TYPE_DIGIC)
> > @@ -18,6 +23,8 @@ typedef struct DigicState {
> >      Object parent_obj;
> >
> >      ARMCPU cpu;
> > +
> > +    DigicTimerState timer[DIGIC4_NB_TIMERS];
> >  } DigicState;
> >
> >  #endif /* __DIGIC_H__ */
> > --
> > 1.8.4.rc3
> >
> >


-- 
-- 
Best regards,
  Antony Pavlov