Re: [Qemu-devel] [PATCH V4 5/7] nios2: Add periodic timer emulation

[Marek Vasut]

On 01/16/2017 11:36 PM, Alexander Graf wrote:
> 
> 
> On 31/12/2016 14:22, Marek Vasut wrote:
>> From: Chris Wulff <address@hidden>
>>
>> Add the Altera timer model.
>>
>> Signed-off-by: Marek Vasut <address@hidden>
>> Cc: Chris Wulff <address@hidden>
>> Cc: Jeff Da Silva <address@hidden>
>> Cc: Ley Foon Tan <address@hidden>
>> Cc: Sandra Loosemore <address@hidden>
>> Cc: Yves Vandervennet <address@hidden>
>> ---
>> V3: Checkpatch cleanup
>> V4: Rebase on top of qemu/master
>> ---
>>  hw/timer/Makefile.objs  |   1 +
>>  hw/timer/altera_timer.c | 237
>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 238 insertions(+)
>>  create mode 100644 hw/timer/altera_timer.c
>>
>> diff --git a/hw/timer/Makefile.objs b/hw/timer/Makefile.objs
>> index 7ba8c23..0867a64 100644
>> --- a/hw/timer/Makefile.objs
>> +++ b/hw/timer/Makefile.objs
>> @@ -18,6 +18,7 @@ common-obj-$(CONFIG_IMX) += imx_gpt.o
>>  common-obj-$(CONFIG_LM32) += lm32_timer.o
>>  common-obj-$(CONFIG_MILKYMIST) += milkymist-sysctl.o
>>
>> +obj-$(CONFIG_ALTERA_TIMER) += altera_timer.o
>>  obj-$(CONFIG_EXYNOS4) += exynos4210_mct.o
>>  obj-$(CONFIG_EXYNOS4) += exynos4210_pwm.o
>>  obj-$(CONFIG_EXYNOS4) += exynos4210_rtc.o
>> diff --git a/hw/timer/altera_timer.c b/hw/timer/altera_timer.c
>> new file mode 100644
>> index 0000000..885242b
>> --- /dev/null
>> +++ b/hw/timer/altera_timer.c
>> @@ -0,0 +1,237 @@
>> +/*
>> + * QEMU model of the Altera timer.
>> + *
>> + * Copyright (c) 2012 Chris Wulff <address@hidden>
>> + *
>> + * 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 2.1 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/lgpl-2.1.html>
>> + */
>> +
>> +#include "qemu/osdep.h"
>> +#include "qemu-common.h"
>> +#include "qapi/error.h"
>> +
>> +#include "hw/sysbus.h"
>> +#include "sysemu/sysemu.h"
>> +#include "hw/ptimer.h"
>> +
>> +#define R_STATUS      0
>> +#define R_CONTROL     1
>> +#define R_PERIODL     2
>> +#define R_PERIODH     3
>> +#define R_SNAPL       4
>> +#define R_SNAPH       5
>> +#define R_MAX         6
>> +
>> +#define STATUS_TO     0x0001
>> +#define STATUS_RUN    0x0002
>> +
>> +#define CONTROL_ITO   0x0001
>> +#define CONTROL_CONT  0x0002
>> +#define CONTROL_START 0x0004
>> +#define CONTROL_STOP  0x0008
>> +
>> +#define TYPE_ALTERA_TIMER "ALTR.timer"
>> +#define ALTERA_TIMER(obj) \
>> +    OBJECT_CHECK(AlteraTimer, (obj), TYPE_ALTERA_TIMER)
>> +
>> +typedef struct AlteraTimer {
>> +    SysBusDevice  busdev;
>> +    MemoryRegion  mmio;
>> +    qemu_irq      irq;
>> +    uint32_t      freq_hz;
>> +    QEMUBH       *bh;
>> +    ptimer_state *ptimer;
>> +    uint32_t      regs[R_MAX];
>> +} AlteraTimer;
>> +
>> +static int timer_irq_state(AlteraTimer *t)
>> +{
>> +    bool irq = (t->regs[R_STATUS] & STATUS_TO) &&
>> +               (t->regs[R_CONTROL] & CONTROL_ITO);
>> +    return irq;
>> +}
>> +
>> +static uint64_t timer_read(void *opaque, hwaddr addr,
>> +                           unsigned int size)
>> +{
>> +    AlteraTimer *t = opaque;
>> +    uint64_t r = 0;
>> +
>> +    addr >>= 2;
>> +    addr &= 0x7;
> 
> You don't need that & here (and below). The ANDing of addresses stems
> from pre-memregion days where you would get the physical address as
> "addr" argument rather than the offset in your region.
> 
>> +    switch (addr) {
>> +    case R_CONTROL:
>> +        r = t->regs[R_CONTROL] & (CONTROL_ITO | CONTROL_CONT);
>> +        break;
>> +
>> +    default:
>> +        if (addr < ARRAY_SIZE(t->regs)) {
>> +            r = t->regs[addr];
>> +        }
>> +        break;
>> +    }
>> +
>> +    return r;
>> +}
>> +
>> +static void timer_write(void *opaque, hwaddr addr,
>> +                        uint64_t value, unsigned int size)
>> +{
>> +    AlteraTimer *t = opaque;
>> +    uint64_t tvalue;
>> +    uint32_t count = 0;
>> +    int irqState = timer_irq_state(t);
>> +
>> +    addr >>= 2;
>> +    addr &= 0x7;
> 
> ^
> 
> Other than that, lgtm.
> 
> Reviewed-by: Alexander Graf <address@hidden>

Fixed, thanks.


-- 
Best regards,
Marek Vasut