RE: [PATCH v3 2/3] power: sequencing: Add Renesas RZ/G3L Power Ready driver

Hi Bartosz Golaszewski,

Thanks for the feedback.

> -----Original Message-----
> From: Bartosz Golaszewski <[email protected]>
> Sent: 13 August 2026 14:50
> Subject: Re: [PATCH v3 2/3] power: sequencing: Add Renesas RZ/G3L Power Ready driver
> 
> On Wed, 12 Aug 2026 13:50:04 +0200, Biju <[email protected]> said:
> > From: Biju Das <[email protected]>
> >
> > Add a power sequencing driver for the Renesas RZ/G3L PWRRDY module,
> > which signals power readiness for various IPs (USB, DSI, CSI etc.) on
> > the SoC. The driver binds as an auxiliary device to the parent SYSC
> > driver, using its regmap to toggle the SYS_PWRRDY_N register bits, and
> > exposes {usb,dsi,csi}-pwrrdy pwrseq targets.
> >
> > Signed-off-by: Biju Das <[email protected]>
> > ---
> > v2->v3:
> >  * Kconfig selects AUXILIARY_BUS to avoid compilation issues.
> >  * Added match for consumer device and added of_device.h header file.
> >  * Replaced regmap_update_bits()->regmap_assign_bits() and updated
> >    the function parameter of pwrseq_rzg3l_set_pwrrdy().
> >  * Simpilfied probe() return with PTR_ERR_OR_ZERO macro.
> > v1->v2:
> >  * Added a comment in pwrseq_rzg3l_pwrrdy_match().
> >  * Dropped dev_get_regmap() from probe as regmap is now part of platform
> >    data.
> >  * Added a blank line before devm_pwrseq_device_register() in probe.
> >  * Dropped the error message devm_pwrseq_device_register() as probe prints
> >    failure message.
> >  * Dropped local variables dev and regmap from probe().
> > ---
> >  drivers/power/sequencing/Kconfig              |   9 ++
> >  drivers/power/sequencing/Makefile             |   1 +
> >  .../power/sequencing/pwrseq-renesas-pwrrdy.c  | 147
> > ++++++++++++++++++
> >  3 files changed, 157 insertions(+)
> >  create mode 100644 drivers/power/sequencing/pwrseq-renesas-pwrrdy.c
> >
> > diff --git a/drivers/power/sequencing/Kconfig
> > b/drivers/power/sequencing/Kconfig
> > index 1c5f5820f5b7..286d4e300845 100644
> > --- a/drivers/power/sequencing/Kconfig
> > +++ b/drivers/power/sequencing/Kconfig
> > @@ -27,6 +27,15 @@ config POWER_SEQUENCING_QCOM_WCN
> >  	  this driver is needed for correct power control or else we'd risk not
> >  	  respecting the required delays between enabling Bluetooth and WLAN.
> >
> > +config POWER_SEQUENCING_RENESAS_PWRRDY
> > +	tristate "Renesas Power Ready sequencing driver"
> > +	depends on SYSC_RZ || COMPILE_TEST
> > +	select AUXILIARY_BUS
> > +	help
> > +	  Say Y here to enable the power sequencing driver for the Renesas
> > +	  Power Ready signals. This driver handles the power ready signals
> > +	  required to power on the various IP's on RZ/G3L platform.
> > +
> >  config POWER_SEQUENCING_TH1520_GPU
> >  	tristate "T-HEAD TH1520 GPU power sequencing driver"
> >  	depends on (ARCH_THEAD && AUXILIARY_BUS) || COMPILE_TEST diff --git
> > a/drivers/power/sequencing/Makefile
> > b/drivers/power/sequencing/Makefile
> > index 0911d4618298..b33d08d82f43 100644
> > --- a/drivers/power/sequencing/Makefile
> > +++ b/drivers/power/sequencing/Makefile
> > @@ -4,5 +4,6 @@ obj-$(CONFIG_POWER_SEQUENCING)		+= pwrseq-core.o
> >  pwrseq-core-y				:= core.o
> >
> >  obj-$(CONFIG_POWER_SEQUENCING_QCOM_WCN)	+= pwrseq-qcom-wcn.o
> > +obj-$(CONFIG_POWER_SEQUENCING_RENESAS_PWRRDY) +=
> > +pwrseq-renesas-pwrrdy.o
> >  obj-$(CONFIG_POWER_SEQUENCING_TH1520_GPU) += pwrseq-thead-gpu.o
> >  obj-$(CONFIG_POWER_SEQUENCING_PCIE_M2)	+= pwrseq-pcie-m2.o
> > diff --git a/drivers/power/sequencing/pwrseq-renesas-pwrrdy.c
> > b/drivers/power/sequencing/pwrseq-renesas-pwrrdy.c
> > new file mode 100644
> > index 000000000000..8dfc65034a1c
> > --- /dev/null
> > +++ b/drivers/power/sequencing/pwrseq-renesas-pwrrdy.c
> > @@ -0,0 +1,147 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Renesas RZ/G3L Power Ready driver
> > + *
> > + */
> > +
> > +#include <linux/auxiliary_bus.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
> > +#include <linux/pwrseq/provider.h>
> > +#include <linux/regmap.h>
> > +
> > +#define SYS_PWRRDY_N		0xd70
> > +#define SYS_PWRRDY_N_USB_MASK	BIT(0)
> > +#define SYS_PWRRDY_N_DSI_MASK	BIT(1)
> > +#define SYS_PWRRDY_N_CSI_MASK	BIT(2)
> > +
> > +static int pwrseq_rzg3l_set_pwrrdy(struct pwrseq_device *pwrseq, u32 mask,
> > +				   bool val)
> > +{
> > +	struct regmap *regmap = pwrseq_device_get_drvdata(pwrseq);
> > +
> > +	return regmap_assign_bits(regmap, SYS_PWRRDY_N, mask, val); }
> > +
> > +static int pwrseq_rzg3l_usb_pwrrdy_enable(struct pwrseq_device
> > +*pwrseq) {
> > +	return pwrseq_rzg3l_set_pwrrdy(pwrseq, SYS_PWRRDY_N_USB_MASK, 0); }
> > +
> > +static int pwrseq_rzg3l_usb_pwrrdy_disable(struct pwrseq_device
> > +*pwrseq) {
> > +	return pwrseq_rzg3l_set_pwrrdy(pwrseq, SYS_PWRRDY_N_USB_MASK, 1); }
> > +
> > +static const struct pwrseq_unit_data pwrseq_rzg3l_usb_pwrrdy_unit = {
> > +	.name = "usb-pwrrdy-power-sequence",
> > +	.enable = pwrseq_rzg3l_usb_pwrrdy_enable,
> > +	.disable = pwrseq_rzg3l_usb_pwrrdy_disable, };
> > +
> > +static int pwrseq_rzg3l_dsi_pwrrdy_enable(struct pwrseq_device
> > +*pwrseq) {
> > +	return pwrseq_rzg3l_set_pwrrdy(pwrseq, SYS_PWRRDY_N_DSI_MASK, 0); }
> > +
> > +static int pwrseq_rzg3l_dsi_pwrrdy_disable(struct pwrseq_device
> > +*pwrseq) {
> > +	return pwrseq_rzg3l_set_pwrrdy(pwrseq, SYS_PWRRDY_N_DSI_MASK, 1); }
> > +
> > +static const struct pwrseq_unit_data pwrseq_rzg3l_dsi_pwrrdy_unit = {
> > +	.name = "dsi-pwrrdy-sequence",
> > +	.enable = pwrseq_rzg3l_dsi_pwrrdy_enable,
> > +	.disable = pwrseq_rzg3l_dsi_pwrrdy_disable, };
> > +
> > +static int pwrseq_rzg3l_csi_pwrrdy_enable(struct pwrseq_device
> > +*pwrseq) {
> > +	return pwrseq_rzg3l_set_pwrrdy(pwrseq, SYS_PWRRDY_N_CSI_MASK, 0); }
> > +
> > +static int pwrseq_rzg3l_csi_pwrrdy_disable(struct pwrseq_device
> > +*pwrseq) {
> > +	return pwrseq_rzg3l_set_pwrrdy(pwrseq, SYS_PWRRDY_N_CSI_MASK, 1); }
> > +
> > +static const struct pwrseq_unit_data pwrseq_rzg3l_csi_pwrrdy_unit = {
> > +	.name = "csi-pwrrdy-power-sequence",
> > +	.enable = pwrseq_rzg3l_csi_pwrrdy_enable,
> > +	.disable = pwrseq_rzg3l_csi_pwrrdy_disable, };
> > +
> > +static const struct pwrseq_target_data pwrseq_rzg3l_usb_pwrrdy_target = {
> > +	.name = "usb-pwrrdy",
> > +	.unit = &pwrseq_rzg3l_usb_pwrrdy_unit, };
> > +
> > +static const struct pwrseq_target_data pwrseq_rzg3l_dsi_pwrrdy_target = {
> > +	.name = "dsi-pwrrdy",
> > +	.unit = &pwrseq_rzg3l_dsi_pwrrdy_unit, };
> > +
> > +static const struct pwrseq_target_data pwrseq_rzg3l_csi_pwrrdy_target = {
> > +	.name = "csi-pwrrdy",
> > +	.unit = &pwrseq_rzg3l_csi_pwrrdy_unit, };
> > +
> > +static const struct pwrseq_target_data *pwrseq_rzg3l_pwrrdy_targets[] = {
> > +	&pwrseq_rzg3l_usb_pwrrdy_target,
> > +	&pwrseq_rzg3l_dsi_pwrrdy_target,
> > +	&pwrseq_rzg3l_csi_pwrrdy_target,
> > +	NULL
> > +};
> > +
> > +static int pwrseq_rzg3l_pwrrdy_match(struct pwrseq_device *pwrseq,
> > +				     struct device *dev)
> > +{
> > +	static const struct of_device_id pwrseq_rzg3l_consumer_match[] = {
> > +		{ .compatible = "renesas,r9a08g046-mipi-dsi" },
> > +		{ .compatible = "renesas,r9a08g046-usbphy-ctrl" },
> > +		{ /* sentinel */ }
> > +	};
> > +	const struct of_device_id *match;
> > +
> > +	match = of_match_device(pwrseq_rzg3l_consumer_match, dev);
> > +	if (!match)
> > +		return PWRSEQ_NO_MATCH;
> > +
> 
> What about the common parent of sysc and the consumers? Is there any reason we can't verify it?

The parent is SoC node [1].

I did not find any value in adding that check. I may be wrong, please correct me.

I will incorporate this, if any based on your feedback.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/arch/arm64/boot/dts/renesas/r9a08g046.dtsi?h=next-20260812#n159


> 
> > +	return PWRSEQ_MATCH_OK;
> > +}
> > +
> > +static int pwrseq_rzg3l_pwrrdy_probe(struct auxiliary_device *adev,
> > +				     const struct auxiliary_device_id *id) {
> > +	struct pwrseq_device *pwrseq;
> > +	struct pwrseq_config config = {
> > +		.parent = &adev->dev,
> > +		.owner = THIS_MODULE,
> > +		.drvdata = adev->dev.platform_data,
> > +		.match = pwrseq_rzg3l_pwrrdy_match,
> > +		.targets = pwrseq_rzg3l_pwrrdy_targets,
> > +	};
> > +
> > +	pwrseq = devm_pwrseq_device_register(&adev->dev, &config);
> > +
> > +	return PTR_ERR_OR_ZERO(pwrseq);
> 
> Just do return PTR_ERR_OR_ZERO(devm_pwrseq_...

Agreed.

Cheers,
Biju