Re: [PATCH v3 1/3] soc: renesas: rz-sysc: Register auxiliary device for PWRRDY power sequencer

[Bartosz Golaszewski]

On Wed, 12 Aug 2026 13:50:03 +0200, Biju <biju.das.au@xxxxxxxxx> said:
> From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
>
> Some RZ SoCs (e.g. RZ/G3L) have a PWRRDY register that is controlled
> through a power sequencer rather than directly by the SYSC driver.
>
> Add a pwrrdy_pwrseq flag to struct rz_sysc_soc_id_init_data to mark
> SoCs with this property, and set it for RZ/G3L. When set,
> rz_sysc_probe() registers a "pwrseq-pwrrdy" auxiliary device so a
> dedicated driver can handle the PWRRDY sequencing.
>
> Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> ---
> v2->v3:
>  * Updated commit description by dropping devm_add_action_or_reset().
>  * Config now selects AUXILIARY_BUS to avoid compilation issues.
>  * Dropped the cast in devm_auxiliary_device_create().
> v1->v2:
>  * Switched to devm_auxiliary_device_create().
>  * Added regmap parameter to rz_sysc_pwrrdy_pwrseq_init(),so that regmap
>    can be passed as platform data.
> ---
>  drivers/soc/renesas/Kconfig          |  1 +
>  drivers/soc/renesas/r9a08g046-sysc.c |  1 +
>  drivers/soc/renesas/rz-sysc.c        | 21 +++++++++++++++++++++
>  drivers/soc/renesas/rz-sysc.h        |  2 ++
>  4 files changed, 25 insertions(+)
>
> diff --git a/drivers/soc/renesas/Kconfig b/drivers/soc/renesas/Kconfig
> index fdf18ed2dfc2..ab1c25fc2656 100644
> --- a/drivers/soc/renesas/Kconfig
> +++ b/drivers/soc/renesas/Kconfig
> @@ -485,6 +485,7 @@ config RZN1_IRQMUX
>  config SYSC_RZ
>  	bool "System controller for RZ SoCs" if COMPILE_TEST
>  	select MFD_SYSCON
> +	select AUXILIARY_BUS
>
>  config SYSC_R9A08G045
>  	bool "Renesas System controller support for R9A08G045 (RZ/G3S)" if COMPILE_TEST
> diff --git a/drivers/soc/renesas/r9a08g046-sysc.c b/drivers/soc/renesas/r9a08g046-sysc.c
> index 90db9d383539..cd129c727461 100644
> --- a/drivers/soc/renesas/r9a08g046-sysc.c
> +++ b/drivers/soc/renesas/r9a08g046-sysc.c
> @@ -76,6 +76,7 @@ static const struct rz_sysc_soc_id_init_data rzg3l_sysc_soc_id_init_data __initc
>  	.devid_offset = 0xa04,
>  	.revision_mask = GENMASK(31, 28),
>  	.specific_id_mask = GENMASK(27, 0),
> +	.pwrrdy_pwrseq = true,
>  };
>
>  const struct rz_sysc_init_data rzg3l_sysc_init_data __initconst = {
> diff --git a/drivers/soc/renesas/rz-sysc.c b/drivers/soc/renesas/rz-sysc.c
> index 161e8c38eea6..79c6af934721 100644
> --- a/drivers/soc/renesas/rz-sysc.c
> +++ b/drivers/soc/renesas/rz-sysc.c
> @@ -5,6 +5,7 @@
>   * Copyright (C) 2024 Renesas Electronics Corp.
>   */
>
> +#include <linux/auxiliary_bus.h>
>  #include <linux/bitfield.h>
>  #include <linux/cleanup.h>
>  #include <linux/io.h>
> @@ -84,6 +85,22 @@ static int rz_sysc_soc_init(struct rz_sysc *sysc, const struct of_device_id *mat
>  	return 0;
>  }
>
> +static int rz_sysc_pwrrdy_pwrseq_init(struct device *dev, struct regmap *regmap,
> +				      const struct rz_sysc_init_data *data)
> +{
> +	const struct rz_sysc_soc_id_init_data *soc_data = data->soc_id_init_data;
> +	struct auxiliary_device *adev;
> +
> +	if (!soc_data->pwrrdy_pwrseq)
> +		return 0;
> +
> +	adev = devm_auxiliary_device_create(dev, "pwrseq-pwrrdy", regmap);
> +	if (!adev)
> +		return -ENODEV;
> +
> +	return 0;
> +}
> +
>  static const struct of_device_id rz_sysc_match[] = {
>  #ifdef CONFIG_SYSC_R9A08G045
>  	{ .compatible = "renesas,r9a08g045-sysc", .data = &rzg3s_sysc_init_data },
> @@ -149,6 +166,10 @@ static int rz_sysc_probe(struct platform_device *pdev)
>  	if (IS_ERR(regmap))
>  		return PTR_ERR(regmap);
>
> +	ret = rz_sysc_pwrrdy_pwrseq_init(dev, regmap, match->data);
> +	if (ret)
> +		return ret;

Honestly I don't think this is worth a separate function, could have as well
been:

	if (match->data->soc_data->pwrrdy_pwrseq) {
		adev = ...
	}

But I won't die on that hill.

Bart

> +
>  	return of_syscon_register_regmap(dev->of_node, regmap);
>  }
>
> diff --git a/drivers/soc/renesas/rz-sysc.h b/drivers/soc/renesas/rz-sysc.h
> index 921ee0d26c47..e55f3258d703 100644
> --- a/drivers/soc/renesas/rz-sysc.h
> +++ b/drivers/soc/renesas/rz-sysc.h
> @@ -20,6 +20,7 @@
>   * @revision_mask: SYSC SoC ID revision mask
>   * @specific_id_mask: SYSC SoC ID specific ID mask
>   * @print_id: print SoC-specific extended device identification
> + * @pwrrdy_pwrseq: has pwrrdy register controlled through power sequencer
>   */
>  struct rz_sysc_soc_id_init_data {
>  	const char * const family;
> @@ -29,6 +30,7 @@ struct rz_sysc_soc_id_init_data {
>  	u32 specific_id_mask;
>  	void (*print_id)(struct device *dev, void __iomem *sysc_base,
>  			 struct soc_device_attribute *soc_dev_attr);
> +	bool pwrrdy_pwrseq;
>  };
>
>  /**
> --
> 2.43.0
>
>