On Thu, 19 Dec 2019 11:23:21 +0100 Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> wrote: > On 19/12/2019 09:15:02+0000, Eugen.Hristev@xxxxxxxxxxxxx wrote: > > > > > > On 18.12.2019 18:58, Alexandre Belloni wrote: > > > On 18/12/2019 16:52:21+0000, Eugen.Hristev@xxxxxxxxxxxxx wrote: > > >> > > >> > > >> On 18.12.2019 18:43, Alexandre Belloni wrote: > > >> > > >>> Hi, > > >>> > > >>> On 18/12/2019 16:24:00+0000, Eugen.Hristev@xxxxxxxxxxxxx wrote: > > >>>> From: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx> > > >>>> > > >>>> This allows the RTC node to have child nodes in DT. > > >>>> This allows subnodes to be probed. > > >>>> > > >>>> Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx> > > >>>> --- > > >>>> drivers/rtc/rtc-at91rm9200.c | 2 +- > > >>>> 1 file changed, 1 insertion(+), 1 deletion(-) > > >>>> > > >>>> diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c > > >>>> index 3b833e0..f1b5b3d 100644 > > >>>> --- a/drivers/rtc/rtc-at91rm9200.c > > >>>> +++ b/drivers/rtc/rtc-at91rm9200.c > > >>>> @@ -421,7 +421,7 @@ static int __init at91_rtc_probe(struct platform_device *pdev) > > >>>> at91_rtc_write_ier(AT91_RTC_SECEV); > > >>>> > > >>>> dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n"); > > >>>> - return 0; > > >>>> + return of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev); > > >>>> > > >>> > > >>> You can avoid the DT binding change and DT parsing by using > > >>> platform_add_device here. I don't think there is any point describing > > >>> the trigger as a child node (a watchdog functionality wouldn't be > > >>> described for example). > > >>> > > >> > > >> Hi, > > >> > > >> It's needed because the ADC needs a link to the trigger device. This is > > >> a hardware link inside the SoC, so I thought the best way is to describe > > >> this hardware is in the Device Tree. > > >> Otherwise the ADC node is unaware of the RTC triggering possibility. > > >> If we just assign the RTC trigger device to the ADC through the sysfs, > > >> the ADC cannot distinguish between the RTC trigger and other various > > >> triggers which can be attached. > > >> > > > > > > I'm not sure this links is required but I will let Jonathan review. Even > > > if it is needed, you can still use the rtc node to describe that link. > > > > Actually, the RTC node could potentially have two different ADC > > triggers. There is another OUT1 field that can do a second trigger for > > the ADC only for the last channel. Future development might add this > > trigger, so, with that in mind, I think it's best to link the exact > > trigger and not the RTC node. > > Nothing prevents you from using an index with the phandle (and I would > add a type in that case then). Having subnodes in the DT is not really a > good idea. The IP is the RTC, it just happens to have some outputs. > See what has been done for the PMC. > > If it can be done either way, let's avoid adding to the rtc dt binding. Jonathan
