Re: [Qemu-devel] [Qemu-devel RFC v3 1/5] msf2: Add Smartfusion2 System timer

[Alistair Francis]

On Fri, Apr 28, 2017 at 9:51 AM, Subbaraya Sundeep
<address@hidden> wrote:
> Modelled System Timer in Microsemi's Smartfusion2 Soc.
> Timer has two 32bit down counters and two interrupts.
>
> Signed-off-by: Subbaraya Sundeep <address@hidden>
> ---
>  hw/timer/Makefile.objs        |   1 +
>  hw/timer/msf2_timer.c         | 250 
> ++++++++++++++++++++++++++++++++++++++++++
>  include/hw/timer/msf2_timer.h |  82 ++++++++++++++
>  3 files changed, 333 insertions(+)
>  create mode 100644 hw/timer/msf2_timer.c
>  create mode 100644 include/hw/timer/msf2_timer.h
>
> diff --git a/hw/timer/Makefile.objs b/hw/timer/Makefile.objs
> index dd6f27e..0bdf1e1 100644
> --- a/hw/timer/Makefile.objs
> +++ b/hw/timer/Makefile.objs
> @@ -41,3 +41,4 @@ common-obj-$(CONFIG_STM32F2XX_TIMER) += stm32f2xx_timer.o
>  common-obj-$(CONFIG_ASPEED_SOC) += aspeed_timer.o
>
>  common-obj-$(CONFIG_SUN4V_RTC) += sun4v-rtc.o
> +common-obj-$(CONFIG_MSF2) += msf2_timer.o
> diff --git a/hw/timer/msf2_timer.c b/hw/timer/msf2_timer.c
> new file mode 100644
> index 0000000..d1dbde5
> --- /dev/null
> +++ b/hw/timer/msf2_timer.c

Hey Sundeep,

File names should use '-' instead of '_'.

> @@ -0,0 +1,250 @@
> +/*
> + * Timer block model of Microsemi SmartFusion2.
> + *
> + * Copyright (c) 2017 Subbaraya Sundeep <address@hidden>.
> + *
> + * 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 "qemu/osdep.h"
> +#include "hw/timer/msf2_timer.h"
> +#include "hw/sysbus.h"
> +#include "qemu/log.h"
> +#include "qemu/main-loop.h"

Do you need to include the main-loop.h? This doesn't look right.

> +
> +#ifndef MSF2_TIMER_ERR_DEBUG
> +#define MSF2_TIMER_ERR_DEBUG  0
> +#endif
> +
> +#define DB_PRINT_L(lvl, fmt, args...) do { \
> +    if (MSF2_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 timer_update_irq(struct Msf2Timer *st)
> +{
> +    bool isr, ier;
> +
> +    isr = !!(st->regs[R_TIM_RIS] & TIMER_RIS_ACK);
> +    ier = !!(st->regs[R_TIM_CTRL] & TIMER_CTRL_INTR);
> +
> +    qemu_set_irq(st->irq, (ier && isr));
> +}
> +
> +static void timer_update(struct Msf2Timer *st)
> +{
> +    uint64_t count;
> +
> +    DB_PRINT("timer=%d\n", st->nr);

Maybe make this a little more explict. Something like "Updating timer: %d"?

> +
> +    if (!(st->regs[R_TIM_CTRL] & TIMER_CTRL_ENBL)) {
> +        ptimer_stop(st->ptimer);
> +        return;
> +    }
> +
> +    count = st->regs[R_TIM_LOADVAL];
> +    ptimer_set_limit(st->ptimer, count, 1);
> +    ptimer_run(st->ptimer, 1);
> +}
> +
> +static uint64_t
> +timer_read(void *opaque, hwaddr addr, unsigned int size)
> +{
> +    MSF2TimerState *t = opaque;
> +    struct Msf2Timer *st;
> +    uint32_t r = 0;

Call the ret instead of r and it should be a uint64_t.

> +    unsigned int timer = 0;

Isn't the timer normally an int? Try to use the same type throughout the code.

> +    int isr;
> +    int ier;
> +
> +    addr >>= 2;
> +    /*
> +     * Two independent timers has same base address.
> +     * Based on addr passed figure out which timer is being used.
> +     */
> +    if (addr >= R_TIM1_MAX) {
> +        timer = 1;
> +        addr -= R_TIM1_MAX;
> +    }
> +
> +    st = &t->timers[timer];
> +
> +    switch (addr) {
> +    case R_TIM_VAL:
> +        r = ptimer_get_count(st->ptimer);
> +        DB_PRINT("msf2_timer t=%d read counter=%x\n", timer, r);

Put a 0x in front of hex values.

Also %x isn't the correct type for uint64_t, it's something similar to PRIx.

> +        break;
> +
> +    case R_TIM_MIS:
> +        isr = !!(st->regs[R_TIM_RIS] & TIMER_RIS_ACK);
> +        ier = !!(st->regs[R_TIM_CTRL] & TIMER_CTRL_INTR);
> +        r = ier && isr;

This should be a bitwise AND.

> +        break;
> +
> +    default:
> +        if (addr < ARRAY_SIZE(st->regs)) {
> +            r = st->regs[addr];
> +        }

If the write is outside the array you should print a guest error.

> +        break;
> +    }
> +    DB_PRINT("timer=%d %lu=%x\n", timer, addr * 4, r);
> +    return r;
> +}
> +
> +static void
> +timer_write(void *opaque, hwaddr addr,
> +            uint64_t val64, unsigned int size)
> +{
> +    MSF2TimerState *t = opaque;
> +    struct Msf2Timer *st;
> +    unsigned int timer = 0;
> +    uint32_t value = val64;
> +
> +    addr >>= 2;
> +    /*
> +     * Two independent timers has same base address.
> +     * Based on addr passed figure out which timer is being used.
> +     */
> +    if (addr >= R_TIM1_MAX) {
> +        timer = 1;
> +        addr -= R_TIM1_MAX;
> +    }
> +
> +    st = &t->timers[timer];
> +
> +    DB_PRINT("addr=%lu val=%x (timer=%d)\n", addr * 4, value, timer);
> +
> +    switch (addr) {
> +    case R_TIM_CTRL:
> +        st->regs[R_TIM_CTRL] = value;
> +        timer_update(st);
> +        break;
> +
> +    case R_TIM_RIS:
> +        if (value & TIMER_RIS_ACK) {
> +            st->regs[R_TIM_RIS] &= ~TIMER_RIS_ACK;
> +        }
> +        break;
> +
> +    case R_TIM_LOADVAL:
> +        st->regs[R_TIM_LOADVAL] = value;
> +        if (st->regs[R_TIM_CTRL] & TIMER_CTRL_ENBL) {
> +            timer_update(st);
> +        }
> +        break;
> +
> +    case R_TIM_BGLOADVAL:
> +        st->regs[R_TIM_BGLOADVAL] = value;
> +        st->regs[R_TIM_LOADVAL] = value;
> +        break;
> +
> +    case R_TIM_VAL:
> +    case R_TIM_MIS:
> +        break;
> +
> +    case R_TIM_MODE:
> +        if (value & TIMER_MODE) {
> +            DB_PRINT("64-bit mode not supported\n");

There is an unimp mask for qemu_log() which you should use here.

> +        }
> +        break;
> +
> +    default:
> +        if (addr < ARRAY_SIZE(st->regs)) {
> +            st->regs[addr] = value;
> +        }
> +        break;
> +    }
> +    timer_update_irq(st);
> +}
> +
> +static const MemoryRegionOps timer_ops = {
> +    .read = timer_read,
> +    .write = timer_write,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +    .valid = {
> +        .min_access_size = 4,
> +        .max_access_size = 4
> +    }
> +};
> +
> +static void timer_hit(void *opaque)
> +{
> +    struct Msf2Timer *st = opaque;
> +
> +    DB_PRINT("%d\n", st->nr);

Maybe make this clearer.

> +    st->regs[R_TIM_RIS] |= TIMER_RIS_ACK;
> +
> +    if (!(st->regs[R_TIM_CTRL] & TIMER_CTRL_ONESHOT)) {
> +        timer_update(st);
> +    }
> +    timer_update_irq(st);
> +}
> +
> +static void msf2_timer_init(Object *obj)
> +{
> +    MSF2TimerState *t = MSF2_TIMER(obj);
> +    unsigned int i;

int i;

> +
> +    /* Init all the ptimers.  */
> +    t->timers = g_malloc0((sizeof t->timers[0]) * NUM_TIMERS);
> +    for (i = 0; i < NUM_TIMERS; i++) {
> +        struct Msf2Timer *st = &t->timers[i];
> +
> +        st->nr = i;
> +        st->bh = qemu_bh_new(timer_hit, st);
> +        st->ptimer = ptimer_init(st->bh, PTIMER_POLICY_DEFAULT);
> +        ptimer_set_freq(st->ptimer, t->freq_hz);
> +        sysbus_init_irq(SYS_BUS_DEVICE(obj), &st->irq);
> +    }
> +
> +    memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t, 
> TYPE_MSF2_TIMER,
> +                          R_TIM_MAX * 4);
> +    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &t->mmio);
> +}
> +
> +static Property msf2_timer_properties[] = {
> +    DEFINE_PROP_UINT32("clock-frequency", MSF2TimerState, freq_hz,
> +                       83 * 1000000),

This value should be a macro.

> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void msf2_timer_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +
> +    dc->props = msf2_timer_properties;
> +}
> +
> +static const TypeInfo msf2_timer_info = {
> +    .name          = TYPE_MSF2_TIMER,
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(MSF2TimerState),
> +    .instance_init = msf2_timer_init,
> +    .class_init    = msf2_timer_class_init,
> +};
> +
> +static void msf2_timer_register_types(void)
> +{
> +    type_register_static(&msf2_timer_info);
> +}
> +
> +type_init(msf2_timer_register_types)
> diff --git a/include/hw/timer/msf2_timer.h b/include/hw/timer/msf2_timer.h
> new file mode 100644
> index 0000000..93d9fb3
> --- /dev/null
> +++ b/include/hw/timer/msf2_timer.h
> @@ -0,0 +1,82 @@
> +/*
> + * Microsemi SmartFusion2 Timer.
> + *
> + * Copyright (c) 2017 Subbaraya Sundeep <address@hidden>
> + *
> + * 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_MSF2_TIMER_H
> +#define HW_MSF2_TIMER_H
> +
> +#include "hw/sysbus.h"
> +#include "hw/ptimer.h"
> +#include "sysemu/sysemu.h"

I think osdep should be included in header files as well.

> +
> +#define TYPE_MSF2_TIMER     "msf2-timer"
> +#define MSF2_TIMER(obj)     OBJECT_CHECK(MSF2TimerState, \
> +                              (obj), TYPE_MSF2_TIMER)
> +
> +/*
> + * There are two 32-bit down counting timers.
> + * Timers 1 and 2 can be concatenated into a single 64-bit Timer
> + * that operates either in Periodic mode or in One-shot mode.
> + * Writing 1 to the TIM64_MODE register bit 0 sets the Timers in 64-bit mode.
> + * In 64-bit mode, writing to the 32-bit registers has no effect.
> + * Similarly, in 32-bit mode, writing to the 64-bit mode registers
> + * has no effect. Only two 32-bit timers are supported currently.
> + */
> +#define NUM_TIMERS        2
> +
> +#define R_TIM_VAL         0
> +#define R_TIM_LOADVAL     1
> +#define R_TIM_BGLOADVAL   2
> +#define R_TIM_CTRL        3
> +#define R_TIM_RIS         4
> +#define R_TIM_MIS         5
> +#define R_TIM1_MAX        6
> +
> +#define R_TIM_MODE       21
> +#define R_TIM_MAX        22 /* including 64-bit timer registers */
> +
> +#define TIMER_CTRL_ENBL     (1 << 0)
> +#define TIMER_CTRL_ONESHOT  (1 << 1)
> +#define TIMER_CTRL_INTR     (1 << 2)
> +#define TIMER_RIS_ACK       (1 << 0)
> +#define TIMER_RST_CLR       (1 << 6)
> +#define TIMER_MODE          (1 << 0)
> +
> +struct Msf2Timer {
> +    QEMUBH *bh;
> +    ptimer_state *ptimer;
> +    int nr; /* for debug. */

What is this used for?

Thanks,

Alistair

> +
> +    uint32_t regs[R_TIM_MAX];
> +    qemu_irq irq;
> +};
> +
> +typedef struct MSF2TimerState {
> +    SysBusDevice parent_obj;
> +
> +    MemoryRegion mmio;
> +    uint32_t freq_hz;
> +    struct Msf2Timer *timers;
> +} MSF2TimerState;
> +
> +#endif /* HW_MSF2_TIMER_H */
> --
> 2.5.0
>