From: Damien Hedde <damien.hedde@greensocs.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: "Daniel P. Berrange" <berrange@redhat.com>,
"Eduardo Habkost" <ehabkost@redhat.com>,
"Alistair Francis" <alistair@alistair23.me>,
"Mark Burton" <mark.burton@greensocs.com>,
"QEMU Developers" <qemu-devel@nongnu.org>,
"Marc-André Lureau" <marcandre.lureau@redhat.com>,
qemu-arm <qemu-arm@nongnu.org>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Edgar E. Iglesias" <edgar.iglesias@gmail.com>,
"Philippe Mathieu-Daudé" <philmd@redhat.com>
Subject: Re: [PATCH v6 5/9] qdev-clock: introduce an init array to ease the device construction
Date: Wed, 4 Dec 2019 12:04:42 +0100 [thread overview]
Message-ID: <102dda6f-ca2d-7d16-0a65-8f6d5a6d1d46@greensocs.com> (raw)
In-Reply-To: <CAFEAcA_Dc7K+NfVAScCk8MYykZ-VrbgJjJwFQCiQ3F7yyseNDQ@mail.gmail.com>
On 12/2/19 4:13 PM, Peter Maydell wrote:
> On Wed, 4 Sep 2019 at 13:56, Damien Hedde <damien.hedde@greensocs.com> wrote:
>>
>> Introduce a function and macro helpers to setup several clocks
>> in a device from a static array description.
>>
>> An element of the array describes the clock (name and direction) as
>> well as the related callback and an optional offset to store the
>> created object pointer in the device state structure.
>>
>> The array must be terminated by a special element QDEV_CLOCK_END.
>>
>> This is based on the original work of Frederic Konrad.
>>
>> Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
>> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>> hw/core/qdev-clock.c | 26 ++++++++++++++++
>> include/hw/qdev-clock.h | 67 +++++++++++++++++++++++++++++++++++++++++
>> 2 files changed, 93 insertions(+)
>>
>> diff --git a/hw/core/qdev-clock.c b/hw/core/qdev-clock.c
>> index bebdd8fa15..32ad45c061 100644
>> --- a/hw/core/qdev-clock.c
>> +++ b/hw/core/qdev-clock.c
>> @@ -153,3 +153,29 @@ void qdev_connect_clock_out(DeviceState *dev, const char *name, ClockIn *clk,
>>
>> clock_connect(clk, clkout);
>> }
>> +
>> +void qdev_init_clocks(DeviceState *dev, const ClockPortInitArray clocks)
>> +{
>> + const struct ClockPortInitElem *elem;
>> +
>> + assert(dev);
>> + assert(clocks);
>
> More unnecessary asserts, I think.
>
>
>
>> +/**
>> + * ClockInitElem:
>> + * @name: name of the clock (can't be NULL)
>> + * @is_output: indicates whether the clock is input or output
>> + * @callback: for inputs, optional callback to be called on clock's update
>> + * with device as opaque
>> + * @offset: optional offset to store the ClockIn or ClockOut pointer in device
>> + * state structure (0 means unused)
>> + */
>> +struct ClockPortInitElem {
>> + const char *name;
>> + bool is_output;
>> + ClockCallback *callback;
>> + size_t offset;
>> +};
>> +
>> +#define clock_offset_value(_type, _devstate, _field) \
>> + (offsetof(_devstate, _field) + \
>> + type_check(_type *, typeof_field(_devstate, _field)))
>
> Avoid leading underscores, please.
>
>> +
>> +#define QDEV_CLOCK(_is_output, _type, _devstate, _field, _callback) { \
>> + .name = (stringify(_field)), \
>> + .is_output = _is_output, \
>> + .callback = _callback, \
>> + .offset = clock_offset_value(_type, _devstate, _field), \
>> +}
>> +
>> +/**
>> + * QDEV_CLOCK_(IN|OUT):
>> + * @_devstate: structure type. @dev argument of qdev_init_clocks below must be
>> + * a pointer to that same type.
>
> It's a bit unclear what "below" here is referring to. Maybe
> just have this be "@devstate: name of a C struct type"
> and then explain below...
>
>> + * @_field: a field in @_devstate (must be ClockIn* or ClockOut*)
>> + * @_callback: (for input only) callback (or NULL) to be called with the device
>> + * state as argument
>> + *
>
> ...here, where we can have a paragraph giving the purpose
> of the macro:
>
> "Define an entry in a ClockPortInitArray which is intended
> to be passed to qdev_init_clocks(), which should be called
> with an @dev argument which is a pointer to the @devstate
> struct type."
Sounds good.
>
>> + * The name of the clock will be derived from @_field
>
> Derived how? Guessing from the stringify(_field) above that it
> will be the same as the field name ?
yes.
>
> It makes sense to hardcode the opaque pointer for the callback to be
> the device pointer.
>
>
>> + */
>> +#define QDEV_CLOCK_IN(_devstate, _field, _callback) \
>> + QDEV_CLOCK(false, ClockIn, _devstate, _field, _callback)
>> +
>> +#define QDEV_CLOCK_OUT(_devstate, _field) \
>> + QDEV_CLOCK(true, ClockOut, _devstate, _field, NULL)
>> +
>> +/**
>> + * QDEV_CLOCK_IN_NOFIELD:
>> + * @_name: name of the clock
>> + * @_callback: callback (or NULL) to be called with the device state as argument
>> + */
>> +#define QDEV_CLOCK_IN_NOFIELD(_name, _callback) { \
>> + .name = _name, \
>> + .is_output = false, \
>> + .callback = _callback, \
>> + .offset = 0, \
>> +}
>
> When would we want to use this one ?
If the callback interaction is enough, we don't need to access the clock
object directly. So we don't need the field in the device state
structure. I can remove this macro for sake of simplicity.
--
Damien
next prev parent reply other threads:[~2019-12-04 12:15 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-04 12:55 [Qemu-devel] [PATCH v6 0/9] Clock framework API Damien Hedde
2019-09-04 12:55 ` [Qemu-devel] [PATCH v6 1/9] hw/core/clock: introduce clock objects Damien Hedde
2019-11-25 13:07 ` Philippe Mathieu-Daudé
2019-11-25 13:37 ` Philippe Mathieu-Daudé
2019-12-03 15:14 ` Damien Hedde
2019-12-02 13:42 ` Peter Maydell
2019-12-03 15:28 ` Damien Hedde
2019-09-04 12:55 ` [Qemu-devel] [PATCH v6 2/9] hw/core/clock-vmstate: define a vmstate entry for clock state Damien Hedde
2019-11-25 13:05 ` Philippe Mathieu-Daudé
2019-12-02 13:44 ` Peter Maydell
2019-09-04 12:55 ` [Qemu-devel] [PATCH v6 3/9] qdev: add clock input&output support to devices Damien Hedde
2019-11-25 13:30 ` Philippe Mathieu-Daudé
2019-12-03 15:35 ` Damien Hedde
2019-12-02 14:34 ` Peter Maydell
2019-12-04 9:05 ` Damien Hedde
2019-12-04 9:53 ` Philippe Mathieu-Daudé
2019-12-04 11:58 ` Damien Hedde
2019-09-04 12:55 ` [Qemu-devel] [PATCH v6 4/9] qdev-monitor: print the device's clock with info qtree Damien Hedde
2019-12-02 14:35 ` Peter Maydell
2019-09-04 12:55 ` [Qemu-devel] [PATCH v6 5/9] qdev-clock: introduce an init array to ease the device construction Damien Hedde
2019-12-02 15:13 ` Peter Maydell
2019-12-04 11:04 ` Damien Hedde [this message]
2019-09-04 12:55 ` [Qemu-devel] [PATCH v6 6/9] docs/clocks: add device's clock documentation Damien Hedde
2019-12-02 15:17 ` Peter Maydell
2019-12-04 12:11 ` Damien Hedde
2019-09-04 12:55 ` [Qemu-devel] [PATCH v6 7/9] hw/misc/zynq_slcr: add clock generation for uarts Damien Hedde
2019-12-02 15:20 ` Peter Maydell
2019-12-04 12:51 ` Damien Hedde
2019-09-04 12:55 ` [Qemu-devel] [PATCH v6 8/9] hw/char/cadence_uart: add clock support Damien Hedde
2019-12-02 15:24 ` Peter Maydell
2019-12-04 13:35 ` Damien Hedde
2019-09-04 12:55 ` [Qemu-devel] [PATCH v6 9/9] hw/arm/xilinx_zynq: connect uart clocks to slcr Damien Hedde
2019-12-02 15:34 ` Peter Maydell
2019-12-03 14:59 ` Damien Hedde
2019-12-03 15:29 ` Philippe Mathieu-Daudé
2019-12-02 16:15 ` [PATCH v6 0/9] Clock framework API Peter Maydell
2019-12-04 16:40 ` Damien Hedde
2019-12-04 20:34 ` Philippe Mathieu-Daudé
2019-12-05 9:36 ` Damien Hedde
2019-12-05 9:59 ` Philippe Mathieu-Daudé
2019-12-05 10:21 ` Dr. David Alan Gilbert
2019-12-05 10:44 ` Philippe Mathieu-Daudé
2019-12-05 10:56 ` Dr. David Alan Gilbert
2019-12-05 11:01 ` Philippe Mathieu-Daudé
2019-12-06 12:46 ` Cleber Rosa
2019-12-06 13:48 ` Dr. David Alan Gilbert
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