Re: [PATCH v2 3/7] iio: adc: add RZ/T2H / RZ/N2H ADC driver

["Nuno Sá" <noname.nuno@gmail.com>]

On Fri, 2025-09-26 at 01:40 +0300, Cosmin Tanislav wrote:
> Add support for the A/D 12-Bit successive approximation converters found
> in the Renesas RZ/T2H (R9A09G077) and RZ/N2H (R9A09G087) SoCs.
> 
> RZ/T2H has two ADCs with 4 channels and one with 6.
> RZ/N2H has two ADCs with 4 channels and one with 15.
> 
> Conversions can be performed in single or continuous mode. Result of the
> conversion is stored in a 16-bit data register corresponding to each
> channel.
> 
> The conversions can be started by a software trigger, a synchronous
> trigger (from MTU or from ELC) or an asynchronous external trigger (from
> ADTRGn# pin).
> 
> Only single mode with software trigger is supported for now.
> 
> Signed-off-by: Cosmin Tanislav <cosmin-gabriel.tanislav.xa@renesas.com>
> ---

Just one small nit from me. With it:

Reviewed-by: Nuno Sá <nuno.sa@analog.com>

>  MAINTAINERS                 |   1 +
>  drivers/iio/adc/Kconfig     |  10 ++
>  drivers/iio/adc/Makefile    |   1 +
>  drivers/iio/adc/rzt2h_adc.c | 306 ++++++++++++++++++++++++++++++++++++
>  4 files changed, 318 insertions(+)
>  create mode 100644 drivers/iio/adc/rzt2h_adc.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index eed08d25cb7a..220d17039084 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -21837,6 +21837,7 @@ L:	linux-iio@vger.kernel.org
>  L:	linux-renesas-soc@vger.kernel.org
>  S:	Supported
>  F:	Documentation/devicetree/bindings/iio/adc/renesas,r9a09g077-adc.yaml
> +F:	drivers/iio/adc/rzt2h_adc.c
>  
>  RENESAS RTCA-3 RTC DRIVER
>  M:	Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 58a14e6833f6..cab5eeba48fe 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -1403,6 +1403,16 @@ config RZG2L_ADC
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called rzg2l_adc.
>  
> +config RZT2H_ADC
> +	tristate "Renesas RZ/T2H / RZ/N2H ADC driver"
> +	select IIO_ADC_HELPER
> +	help
> +	  Say yes here to build support for the ADC found in Renesas
> +	  RZ/T2H / RZ/N2H SoCs.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called rzt2h_adc.
> +
>  config SC27XX_ADC
>  	tristate "Spreadtrum SC27xx series PMICs ADC"
>  	depends on MFD_SC27XX_PMIC || COMPILE_TEST
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index d008f78dc010..ed647a734c51 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -123,6 +123,7 @@ obj-$(CONFIG_ROHM_BD79112) += rohm-bd79112.o
>  obj-$(CONFIG_ROHM_BD79124) += rohm-bd79124.o
>  obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
>  obj-$(CONFIG_RZG2L_ADC) += rzg2l_adc.o
> +obj-$(CONFIG_RZT2H_ADC) += rzt2h_adc.o
>  obj-$(CONFIG_SC27XX_ADC) += sc27xx_adc.o
>  obj-$(CONFIG_SD_ADC_MODULATOR) += sd_adc_modulator.o
>  obj-$(CONFIG_SOPHGO_CV1800B_ADC) += sophgo-cv1800b-adc.o
> diff --git a/drivers/iio/adc/rzt2h_adc.c b/drivers/iio/adc/rzt2h_adc.c
> new file mode 100644
> index 000000000000..6a49788a5c67
> --- /dev/null
> +++ b/drivers/iio/adc/rzt2h_adc.c
> @@ -0,0 +1,306 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <linux/bitfield.h>
> +#include <linux/cleanup.h>
> +#include <linux/completion.h>
> +#include <linux/delay.h>
> +#include <linux/iio/adc-helpers.h>
> +#include <linux/iio/iio.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/iopoll.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/property.h>
> +

...

> 
> +
> +static int rzt2h_adc_pm_runtime_resume(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct rzt2h_adc *adc = iio_priv(indio_dev);

Not seeing the point of the pointer arithmetic. You can pass your device pointer
(adc) directly in platform_set_drvdata()

- Nuno Sá