Re: [PATCH 4/8] mac_via: add GPIO for A/UX mode

[Laurent Vivier]

Le 15/10/2021 à 21:50, Mark Cave-Ayland a écrit :
> On 15/10/2021 07:58, Laurent Vivier wrote:
> 
>> Le 13/10/2021 à 23:21, Mark Cave-Ayland a écrit :
>>> Add a new auxmode GPIO that is updated when port B bit 6 is changed 
>>> indicating
>>> whether the hardware is configured for A/UX mode.
>>>
>>> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
>>> ---
>>>   hw/misc/mac_via.c         | 18 ++++++++++++++++++
>>>   hw/misc/trace-events      |  1 +
>>>   include/hw/misc/mac_via.h |  1 +
>>>   3 files changed, 20 insertions(+)
>>>
>>> diff --git a/hw/misc/mac_via.c b/hw/misc/mac_via.c
>>> index 7a53a8b4c0..a08ffbcd88 100644
>>> --- a/hw/misc/mac_via.c
>>> +++ b/hw/misc/mac_via.c
>>> @@ -880,6 +880,20 @@ static void via1_adb_update(MOS6522Q800VIA1State *v1s)
>>>       }
>>>   }
>>>   +static void via1_auxmode_update(MOS6522Q800VIA1State *v1s)
>>> +{
>>> +    MOS6522State *s = MOS6522(v1s);
>>> +    int oldirq, irq;
>>> +
>>
>> Please, add a comment to explain what happens here as "vMystery" is not 
>> self-explicit.
> 
> Would something simple like:
> 
> /* Check to see if the A/UX mode bit has changed */
> 
> suffice here?

Yes

> 
>>> +    oldirq = (v1s->last_b & VIA1B_vMystery) ? 1 : 0;
>>> +    irq = (s->b & VIA1B_vMystery) ? 1 : 0;
>>
>> For me, it would be clearer with:
>>
>>      oldirq = !!(v1s->last_b & VIA1B_vMystery);
>>      irq = !!(s->b & VIA1B_vMystery);
>>
>> but it's a matter of taste.
> 
> I had to think carefully about that one :)  If you're fine with the existing 
> version I'd prefer to
> keep it as I find it easier to read.

Up to you, as I said, a matter of taste.

> 
>>> +
>>> +    if (irq != oldirq) {
>>> +        trace_via1_auxmode(irq);
>>> +        qemu_set_irq(v1s->auxmode_irq, irq);
>>> +    }
>>> +}
>>> +
>>>   static uint64_t mos6522_q800_via1_read(void *opaque, hwaddr addr, 
>>> unsigned size)
>>>   {
>>>       MOS6522Q800VIA1State *s = MOS6522_Q800_VIA1(opaque);
>>> @@ -902,6 +916,7 @@ static void mos6522_q800_via1_write(void *opaque, 
>>> hwaddr addr, uint64_t val,
>>>       case VIA_REG_B:
>>>           via1_rtc_update(v1s);
>>>           via1_adb_update(v1s);
>>> +        via1_auxmode_update(v1s);
>>>             v1s->last_b = ms->b;
>>>           break;
>>> @@ -1046,6 +1061,9 @@ static void mos6522_q800_via1_init(Object *obj)
>>>                 TYPE_ADB_BUS, DEVICE(v1s), "adb.0");
>>>         qdev_init_gpio_in(DEVICE(obj), via1_irq_request, VIA1_IRQ_NB);
>>> +
>>> +    /* A/UX mode */
>>> +    qdev_init_gpio_out(DEVICE(obj), &v1s->auxmode_irq, 1);
>>>   }
>>>     static const VMStateDescription vmstate_q800_via1 = {
>>> diff --git a/hw/misc/trace-events b/hw/misc/trace-events
>>> index ede413965b..2da96d167a 100644
>>> --- a/hw/misc/trace-events
>>> +++ b/hw/misc/trace-events
>>> @@ -228,6 +228,7 @@ via1_rtc_cmd_pram_sect_write(int sector, int offset, 
>>> int addr, int value) "secto
>>>   via1_adb_send(const char *state, uint8_t data, const char *vadbint) 
>>> "state %s data=0x%02x
>>> vADBInt=%s"
>>>   via1_adb_receive(const char *state, uint8_t data, const char *vadbint, 
>>> int status, int index,
>>> int size) "state %s data=0x%02x vADBInt=%s status=0x%x index=%d size=%d"
>>>   via1_adb_poll(uint8_t data, const char *vadbint, int status, int index, 
>>> int size) "data=0x%02x
>>> vADBInt=%s status=0x%x index=%d size=%d"
>>> +via1_auxmode(int mode) "setting auxmode to %d"
>>>     # grlib_ahb_apb_pnp.c
>>>   grlib_ahb_pnp_read(uint64_t addr, uint32_t value) "AHB PnP read 
>>> addr:0x%03"PRIx64" data:0x%08x"
>>> diff --git a/include/hw/misc/mac_via.h b/include/hw/misc/mac_via.h
>>> index 4506abe5d0..b445565866 100644
>>> --- a/include/hw/misc/mac_via.h
>>> +++ b/include/hw/misc/mac_via.h
>>> @@ -43,6 +43,7 @@ struct MOS6522Q800VIA1State {
>>>       MemoryRegion via_mem;
>>>         qemu_irq irqs[VIA1_IRQ_NB];
>>> +    qemu_irq auxmode_irq;
>>>       uint8_t last_b;
>>>         /* RTC */
>>>
>>
>> Reviewed-by: Laurent Vivier <laurent@vivier.eu>
> 
> 
> ATB,
> 
> Mark.