On Thu, 26 Jan 2023, Biju Das wrote:
> Hi Daniel,
>
> + Rob and Krzysztof Kozlowski
>
> > -----Original Message-----
> > From: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> > Sent: Thursday, January 26, 2023 10:53 AM
> > To: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>; Philipp Zabel
> > <p.zabel@xxxxxxxxxxxxxx>
> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>; Geert Uytterhoeven
> > <geert+renesas@xxxxxxxxx>; Chris Paterson <Chris.Paterson2@xxxxxxxxxxx>;
> > Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>; linux-
> > renesas-soc@xxxxxxxxxxxxxxx; Lee Jones <lee@xxxxxxxxxx>
> > Subject: Re: [PATCH v11 2/6] clocksource/drivers: Add Renesas RZ/G2L MTU3a
> > core driver
> >
> > On 13/01/2023 17:17, Biju Das wrote:
> >
> > [ ... ]
> >
> > > +config RZ_MTU3
> > > + bool "Renesas RZ/G2L MTU3a core driver"
> > > + select MFD_CORE
> > > + depends on (ARCH_RZG2L && OF) || COMPILE_TEST
> > > + help
> > > + Select this option to enable Renesas RZ/G2L MTU3a core driver for
> > > + the Multi-Function Timer Pulse Unit 3 (MTU3a) hardware available
> > > + on SoCs from Renesas. The core driver shares the clk and channel
> > > + register access for the other child devices like Counter, PWM,
> > > + Clock Source, and Clock event.
> >
> > Do you really want to have this option manually selectable? Usually we try
> > to avoid that and keep a silent option which is selected by the platform
> > config.
>
> For critical drivers like CPG, Pinctrl we enable it by default by silent option in platform config.
> For the others we add it to defconfig, once the device tree support is available.
>
>
> >
> > [ ... ]
> >
> > > +
> > > + ret = mfd_add_devices(&pdev->dev, 0, rz_mtu3_devs,
> > > + ARRAY_SIZE(rz_mtu3_devs), NULL, 0, NULL);
> > > + if (ret < 0)
> > > + goto err_assert;
> > > +
> > > + return devm_add_action_or_reset(&pdev->dev, rz_mtu3_reset_assert,
> > > + &pdev->dev);
> > > +
> > > +err_assert:
> > > + reset_control_assert(ddata->rstc);
> > > + return ret;
> > > +}
> >
> > I'm not sure this driver falls under the clocksource umbrella but under
> > mfd [cc'ed Lee Jones]
> >
>
>
> Please find [1],
>
> After a long discussion with dt maintainers, counter maintainer, MFD maintainer and PWM maintainer, it is concluded to
> Add the core driver to timer subsystem.
Which is fine. However, you cannot then use the MFD API.
> [1] https://patchwork.kernel.org/project/linux-renesas-soc/patch/20221010145222.1047748-2-biju.das.jz@xxxxxxxxxxxxxx/
"The TL;DR is: if you're not using the MFD Core (and including
mfd/core.h), it's not an MFD. You *could* split this up into its
component parts, place them into their own subsystems and use an MFD
core driver to register them all, but as Thierry says, this is not a
hard requirement either."
--
Lee Jones [李琼斯]
