Messages in this thread | | | Date | Thu, 17 Jun 2021 09:27:08 +0100 | From | Lee Jones <> | Subject | Re: [PATCH] mfd: mfd-core: Change "Failed to locate of_node" warning to debug |
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On Thu, 17 Jun 2021, Yunus Bas wrote:
> Hi Lee, > > Am Mittwoch, dem 16.06.2021 um 10:03 +0100 schrieb Lee Jones: > > On Wed, 16 Jun 2021, Yunus Bas wrote: > > > > > The MFD-core iterates through all subdevices of the corresponding > > > MFD-device and checks, if the devicetree subnode has a fitting > > > compatible. > > > When nothing is found, a warning is thrown. This can be the case, > > > when it > > > is the intention to not use the MFD-device to it's full content. > > > Therefore, change the warning to a debug print instead, to also avoid > > > irritations. > > > > > > Signed-off-by: Yunus Bas <y.bas@phytec.de> > > > --- > > > drivers/mfd/mfd-core.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c > > > index 6f02b8022c6d..e34c97088943 100644 > > > --- a/drivers/mfd/mfd-core.c > > > +++ b/drivers/mfd/mfd-core.c > > > @@ -213,7 +213,7 @@ static int mfd_add_device(struct device *parent, > > > int id, > > > } > > > > > > if (!pdev->dev.of_node) > > > - pr_warn("%s: Failed to locate of_node [id: > > > %d]\n", > > > + pr_debug("%s: Failed to locate of_node [id: > > > %d]\n", > > > cell->name, platform_id); > > > } > > > > Can you provide an example of a device tree where this is a problem? > > Of course, sorry for the poor description. > > Here is an example of the imx6qdl-phytec-phycore-som.dtsi which uses > the DA9062 multi-functional device. The DA9062 has five mfd-cell > devices with compatibles defined as subfunctions. The devicetree needs > and uses just three of them: > > ... > pmic: pmic@58 { > compatible = "dlg,da9062"; > pinctrl-names = "default"; > pinctrl-0 = <&pinctrl_pmic>; > reg = <0x58>; > interrupt-parent = <&gpio1>; > interrupts = <2 IRQ_TYPE_LEVEL_LOW>; > interrupt-controller; > gpio-controller; > #gpio-cells = <2>; > > da9062_rtc: rtc { > compatible = "dlg,da9062-rtc"; > }; > > da9062_onkey: onkey { > compatible = "dlg,da9062-onkey"; > }; > > watchdog { > compatible = "dlg,da9062-watchdog"; > dlg,use-sw-pm; > } > ...
So, looking at the mfd_cells table, I see:
static const struct mfd_cell da9061_devs[] = { { .name = "da9061-core", .num_resources = ARRAY_SIZE(da9061_core_resources), .resources = da9061_core_resources, }, { .name = "da9062-regulators", .num_resources = ARRAY_SIZE(da9061_regulators_resources), .resources = da9061_regulators_resources, }, { .name = "da9061-watchdog", .num_resources = ARRAY_SIZE(da9061_wdt_resources), .resources = da9061_wdt_resources, .of_compatible = "dlg,da9061-watchdog", }, { .name = "da9061-thermal", .num_resources = ARRAY_SIZE(da9061_thermal_resources), .resources = da9061_thermal_resources, .of_compatible = "dlg,da9061-thermal", }, { .name = "da9061-onkey", .num_resources = ARRAY_SIZE(da9061_onkey_resources), .resources = da9061_onkey_resources, .of_compatible = "dlg,da9061-onkey", }, };
Not sure why "da9061-core" is even in there. It looks like this would be referencing itself (if this driver's name contained the "-core" element). So what from I can tell, I think this entry should actually just be removed.
With regards to "da9062-regulators", this looks like an oversight at best or a Linux hack at worst. Device Tree is designed to be OS agnostic. It should describe the H/W as-is, which would include the Regulator functionality. Choosing to opt-out and instead use Linux specific systems (i.e. MFD) for device registration is a hack.
I've always said we should not mix DT and MFD in this way.
> Since the driver iterates through the mfd_cells-struct tries matching > compatibles in the devicetree MFD node, it throws a warning when there > is no counterpart in the devicetree. > > In fact, I could also evalutate oder devicetree's using MFD-devices not > to it's full content. > > > > > Probably worth popping that in the commit message too. > > Yes, I will send a v2 ASAP. Thank you for the advice.
I think the current code is fine as it is.
It's the implementation that needs to change.
Maybe Steve would like to comment?
-- Lee Jones [李琼斯] Senior Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog
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