Re: [RFC PATCH v5 3/6] PM / devfreq: exynos-bus: Add registration of interconnect child device

From: Chanwoo Choi
Date: Mon Jun 01 2020 - 20:40:57 EST


Hi Sylwester,

On 6/1/20 7:04 PM, Sylwester Nawrocki wrote:
> Cc: Rob, devicetree ML
>
> On 31.05.2020 01:57, Chanwoo Choi wrote:
>> On Sat, May 30, 2020 at 1:33 AM Sylwester Nawrocki
>> <s.nawrocki@xxxxxxxxxxx> wrote:
>>>
>>> This patch adds registration of a child platform device for the exynos
>>> interconnect driver. It is assumed that the interconnect provider will
>>> only be needed when #interconnect-cells property is present in the bus
>>> DT node, hence the child device will be created only when such a property
>>> is present.
>>>
>>> Signed-off-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
>>>
>>> Changes for v5:
>>> - new patch.
>>> ---
>>> drivers/devfreq/exynos-bus.c | 17 +++++++++++++++++
>>> 1 file changed, 17 insertions(+)
>>>
>>> diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
>>> index 8fa8eb5..856e37d 100644
>>> --- a/drivers/devfreq/exynos-bus.c
>>> +++ b/drivers/devfreq/exynos-bus.c
>>> @@ -24,6 +24,7 @@
>>>
>>> struct exynos_bus {
>>> struct device *dev;
>>> + struct platform_device *icc_pdev;
>>>
>>> struct devfreq *devfreq;
>>> struct devfreq_event_dev **edev;
>>> @@ -156,6 +157,8 @@ static void exynos_bus_exit(struct device *dev)
>>> if (ret < 0)
>>> dev_warn(dev, "failed to disable the devfreq-event devices\n");
>>>
>>> + platform_device_unregister(bus->icc_pdev);
>>> +
>>> dev_pm_opp_of_remove_table(dev);
>>> clk_disable_unprepare(bus->clk);
>>> if (bus->opp_table) {
>>> @@ -168,6 +171,8 @@ static void exynos_bus_passive_exit(struct device *dev)
>>> {
>>> struct exynos_bus *bus = dev_get_drvdata(dev);
>>>
>>> + platform_device_unregister(bus->icc_pdev);
>>> +
>>> dev_pm_opp_of_remove_table(dev);
>>> clk_disable_unprepare(bus->clk);
>>> }
>>> @@ -431,6 +436,18 @@ static int exynos_bus_probe(struct platform_device *pdev)
>>> if (ret < 0)
>>> goto err;
>>>
>>> + /* Create child platform device for the interconnect provider */
>>> + if (of_get_property(dev->of_node, "#interconnect-cells", NULL)) {
>>> + bus->icc_pdev = platform_device_register_data(
>>> + dev, "exynos-generic-icc",
>>> + PLATFORM_DEVID_AUTO, NULL, 0);
>>> +
>>> + if (IS_ERR(bus->icc_pdev)) {
>>> + ret = PTR_ERR(bus->icc_pdev);
>>> + goto err;
>>> + }
>>> + }
>>> +
>>> max_state = bus->devfreq->profile->max_state;
>>> min_freq = (bus->devfreq->profile->freq_table[0] / 1000);
>>> max_freq = (bus->devfreq->profile->freq_table[max_state - 1] / 1000);
>>> --
>>> 2.7.4
>>>
>>
>> It looks like very similar like the registering the interconnect
>> device of imx-bus.c
>> and I already reviewed and agreed this approach.
>>
>> Acked-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
>>
>> nitpick: IMHO, I think that 'exynos-icc' is proper and simple without
>> 'generic' word.
>> If we need to add new icc compatible int the future, we will add
>> 'exynosXXXX-icc' new compatible.
>> But, I'm not forcing it. just opinion. Anyway, I agree this approach.
>
> Thanks for review. I will change the name to exynos-icc in next version,
> as I commented at other patch, it is not part of any DT binding,
> it is just for device/driver matching between devfreq and interconnect.

Thanks. I have not any objection to use either 'exynos-generic-icc'
or 'exynos-icc'. It is just my opinion. And on next version,
please add linux-pm mailing list to Cc.

--
Best Regards,
Chanwoo Choi
Samsung Electronics