Re: [PATCH v4 5/6 RESEND] mfd: motorola-cpcap: diverge configuration per-board

[Lee Jones <lee@kernel.org>]

On Thu, 07 May 2026, Svyatoslav Ryhel wrote:

> чт, 7 трав. 2026 р. о 17:05 Lee Jones <lee@kernel.org> пише:
> >
> > On Tue, 28 Apr 2026, Svyatoslav Ryhel wrote:
> >
> > > MFD have rigid subdevice structure which does not allow flexible dynamic
> > > subdevice linking. Address this by diverging CPCAP subdevice composition
> > > to take into account board specific configuration.
> > >
> > > Create a common default subdevice composition, rename existing subdevice
> > > composition into cpcap_mapphone_mfd_devices since it targets mainly
> > > Mapphone board.
> > >
> > > Removed st,6556002 as it is no longer applicable to all cases and
> > > duplicates motorola,cpcap, which is used as the default composition.
> > >
> > > Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> > > ---
> >
> > Changelog?
> >
> 
> Changelog is in the cover.
> 
> > >  drivers/mfd/motorola-cpcap.c | 101 ++++++++++++++++++++++++++++-------
> > >  1 file changed, 83 insertions(+), 18 deletions(-)
> > >
> > > diff --git a/drivers/mfd/motorola-cpcap.c b/drivers/mfd/motorola-cpcap.c
> > > index d8243b956f87..516d1e33affa 100644
> > > --- a/drivers/mfd/motorola-cpcap.c
> > > +++ b/drivers/mfd/motorola-cpcap.c
> > > @@ -12,6 +12,7 @@
> > >  #include <linux/kernel.h>
> > >  #include <linux/module.h>
> > >  #include <linux/mod_devicetable.h>
> > > +#include <linux/property.h>
> > >  #include <linux/regmap.h>
> > >  #include <linux/sysfs.h>
> > >
> > > @@ -24,10 +25,16 @@
> > >  #define CPCAP_REGISTER_SIZE  4
> > >  #define CPCAP_REGISTER_BITS  16
> > >
> > > +struct cpcap_chip_data {
> > > +     const struct mfd_cell *mfd_devices;
> > > +     unsigned int num_devices;
> > > +};
> >
> > This is a red flag.
> >
> > >  struct cpcap_ddata {
> > >       struct spi_device *spi;
> > >       struct regmap_irq *irqs;
> > >       struct regmap_irq_chip_data *irqdata[CPCAP_NR_IRQ_CHIPS];
> > > +     const struct cpcap_chip_data *cdata;
> > >       const struct regmap_config *regmap_conf;
> > >       struct regmap *regmap;
> > >  };
> > > @@ -195,20 +202,6 @@ static int cpcap_init_irq(struct cpcap_ddata *cpcap)
> > >       return 0;
> > >  }
> > >
> > > -static const struct of_device_id cpcap_of_match[] = {
> > > -     { .compatible = "motorola,cpcap", },
> > > -     { .compatible = "st,6556002", },
> > > -     {},
> > > -};
> > > -MODULE_DEVICE_TABLE(of, cpcap_of_match);
> > > -
> > > -static const struct spi_device_id cpcap_spi_ids[] = {
> > > -     { .name = "cpcap", },
> > > -     { .name = "6556002", },
> > > -     {},
> > > -};
> > > -MODULE_DEVICE_TABLE(spi, cpcap_spi_ids);
> > > -
> > >  static const struct regmap_config cpcap_regmap_config = {
> > >       .reg_bits = 16,
> > >       .reg_stride = 4,
> > > @@ -241,7 +234,56 @@ static int cpcap_resume(struct device *dev)
> > >
> > >  static DEFINE_SIMPLE_DEV_PM_OPS(cpcap_pm, cpcap_suspend, cpcap_resume);
> > >
> > > -static const struct mfd_cell cpcap_mfd_devices[] = {
> > > +static const struct mfd_cell cpcap_default_mfd_devices[] = {
> > > +     {
> > > +             .name          = "cpcap_adc",
> > > +             .of_compatible = "motorola,cpcap-adc",
> > > +     }, {
> > > +             .name          = "cpcap_battery",
> > > +             .of_compatible = "motorola,cpcap-battery",
> > > +     }, {
> > > +             .name          = "cpcap-regulator",
> > > +             .of_compatible = "motorola,cpcap-regulator",
> > > +     }, {
> > > +             .name          = "cpcap-rtc",
> > > +             .of_compatible = "motorola,cpcap-rtc",
> > > +     }, {
> > > +             .name          = "cpcap-pwrbutton",
> > > +             .of_compatible = "motorola,cpcap-pwrbutton",
> > > +     }, {
> > > +             .name          = "cpcap-usb-phy",
> > > +             .of_compatible = "motorola,cpcap-usb-phy",
> > > +     }, {
> > > +             .name          = "cpcap-led",
> > > +             .id            = 0,
> > > +             .of_compatible = "motorola,cpcap-led-red",
> > > +     }, {
> > > +             .name          = "cpcap-led",
> > > +             .id            = 1,
> > > +             .of_compatible = "motorola,cpcap-led-green",
> > > +     }, {
> > > +             .name          = "cpcap-led",
> > > +             .id            = 2,
> > > +             .of_compatible = "motorola,cpcap-led-blue",
> > > +     }, {
> > > +             .name          = "cpcap-led",
> > > +             .id            = 3,
> > > +             .of_compatible = "motorola,cpcap-led-adl",
> > > +     }, {
> > > +             .name          = "cpcap-led",
> > > +             .id            = 4,
> > > +             .of_compatible = "motorola,cpcap-led-cp",
> > > +     }, {
> > > +             .name          = "cpcap-codec",
> > > +     },
> > > +};
> > > +
> > > +static const struct cpcap_chip_data cpcap_default_data = {
> > > +     .mfd_devices = cpcap_default_mfd_devices,
> > > +     .num_devices = ARRAY_SIZE(cpcap_default_mfd_devices),
> > > +};
> > > +
> > > +static const struct mfd_cell cpcap_mapphone_mfd_devices[] = {
> > >       {
> > >               .name          = "cpcap_adc",
> > >               .of_compatible = "motorola,mapphone-cpcap-adc",
> > > @@ -285,7 +327,12 @@ static const struct mfd_cell cpcap_mfd_devices[] = {
> > >               .of_compatible = "motorola,cpcap-led-cp",
> > >       }, {
> > >               .name          = "cpcap-codec",
> > > -     }
> > > +     },
> > > +};
> > > +
> > > +static const struct cpcap_chip_data cpcap_mapphone_data = {
> > > +     .mfd_devices = cpcap_mapphone_mfd_devices,
> > > +     .num_devices = ARRAY_SIZE(cpcap_mapphone_mfd_devices),
> > >  };
> > >
> > >  static int cpcap_probe(struct spi_device *spi)
> > > @@ -297,9 +344,17 @@ static int cpcap_probe(struct spi_device *spi)
> > >       if (!cpcap)
> > >               return -ENOMEM;
> > >
> > > +     cpcap->cdata = device_get_match_data(&spi->dev);
> > > +     if (!cpcap->cdata)
> > > +             return -ENODEV;
> > > +
> > >       cpcap->spi = spi;
> > >       spi_set_drvdata(spi, cpcap);
> > >
> > > @@ -331,16 +382,24 @@ static int cpcap_probe(struct spi_device *spi)
> > >       spi->dev.coherent_dma_mask = 0;
> > >       spi->dev.dma_mask = &spi->dev.coherent_dma_mask;
> > >
> > > -     return devm_mfd_add_devices(&spi->dev, 0, cpcap_mfd_devices,
> > > -                                 ARRAY_SIZE(cpcap_mfd_devices), NULL, 0, NULL);
> > > +     return devm_mfd_add_devices(&spi->dev, 0, cpcap->cdata->mfd_devices,
> > > +                                 cpcap->cdata->num_devices, NULL, 0, NULL);
> > >  }
> > >
> > > +static const struct of_device_id cpcap_of_match[] = {
> > > +     { .compatible = "motorola,cpcap", .data = &cpcap_default_data },
> > > +     { .compatible = "motorola,mapphone-cpcap", .data = &cpcap_mapphone_data },
> >
> > We don't allow data from one device registration API (MFD) to be passed
> > through another (OF) because it tends to lead to all sorts of "creative
> > solutions".  Pass a value instead and match on that in a switch()
> > statement like all of the other MFD drivers do.
> >
> 
> You don't allow this. I have not seen this enforced anywhere in the
> kernel except the mfd subsystem. Fine, does not matter, if this makes
> you happy I will adjust.

Where else would this rule be applicable?  I can't think of anywhere.

-- 
Lee Jones