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

[Lee Jones <lee@kernel.org>]

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 Removed st,6556002 as it is no longer applicable to all cases and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?

>  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.

> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, cpcap_of_match);
> +
> +static const struct spi_device_id cpcap_spi_ids[] = {
> +	{ .name = "cpcap", .driver_data = (kernel_ulong_t)&cpcap_default_data },
> +	{ .name = "mapphone-cpcap", .driver_data = (kernel_ulong_t)&cpcap_mapphone_data },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(spi, cpcap_spi_ids);
> +
>  static struct spi_driver cpcap_driver = {
>  	.driver = {
>  		.name = "cpcap-core",
> -- 
> 2.51.0
> 
> 

-- 
Lee Jones