Re: [PATCH v3 3/3] reset: eswin: Add eic7700 HSP reset driver

[Philipp Zabel <p.zabel@pengutronix.de>]

On Do, 2026-04-23 at 17:12 +0800, dongxuyang@eswincomputing.com wrote:
> From: Xuyang Dong <dongxuyang@eswincomputing.com>
> 
> Add auxiliary driver to support ESWIN EIC7700 high-speed peripherals
> system. The reset controller is created using the auxiliary device
> framework and set up in the clock driver.
> 
> Signed-off-by: Xuyang Dong <dongxuyang@eswincomputing.com>
> ---
>  drivers/reset/Kconfig             |  11 +++
>  drivers/reset/Makefile            |   1 +
>  drivers/reset/reset-eic7700-hsp.c | 118 ++++++++++++++++++++++++++++++
>  3 files changed, 130 insertions(+)
>  create mode 100644 drivers/reset/reset-eic7700-hsp.c
> 
> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> index d009eb0849a3..f63e89ed6a4e 100644
> --- a/drivers/reset/Kconfig
> +++ b/drivers/reset/Kconfig
> @@ -83,6 +83,17 @@ config RESET_EIC7700
>  	  The driver supports eic7700 series chips and provides functionality for
>  	  asserting and deasserting resets on the chip.
>  
> +config RESET_EIC7700_HSP
> +	tristate "EIC7700 HSP Reset controller"
> +	depends on ARCH_ESWIN || COMPILE_TEST
> +	select AUXILIARY_BUS
> +	help
> +	  This enables the HSP reset controller driver for ESWIN SoCs. This
> +	  driver is specific to ESWIN SoCs and should only be enabled if using
> +	  such hardware.
> +	  The driver supports EIC7700 series chips and provides functionality
> +	  for asserting and deasserting resets on the chip.
> +
>  config RESET_EYEQ
>  	bool "Mobileye EyeQ reset controller"
>  	depends on EYEQ || COMPILE_TEST
> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
> index 3e52569bd276..a75af831ef58 100644
> --- a/drivers/reset/Makefile
> +++ b/drivers/reset/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o
>  obj-$(CONFIG_RESET_BRCMSTB) += reset-brcmstb.o
>  obj-$(CONFIG_RESET_BRCMSTB_RESCAL) += reset-brcmstb-rescal.o
>  obj-$(CONFIG_RESET_EIC7700) += reset-eic7700.o
> +obj-$(CONFIG_RESET_EIC7700_HSP) += reset-eic7700-hsp.o
>  obj-$(CONFIG_RESET_EYEQ) += reset-eyeq.o
>  obj-$(CONFIG_RESET_GPIO) += reset-gpio.o
>  obj-$(CONFIG_RESET_HSDK) += reset-hsdk.o
> diff --git a/drivers/reset/reset-eic7700-hsp.c b/drivers/reset/reset-eic7700-hsp.c
> new file mode 100644
> index 000000000000..dde1f9bffa61
> --- /dev/null
> +++ b/drivers/reset/reset-eic7700-hsp.c
> @@ -0,0 +1,118 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2026, Beijing ESWIN Computing Technology Co., Ltd..
> + * All rights reserved.
> + *
> + * ESWIN EIC7700 HSP Reset Driver
> + *
> + * Authors: Xuyang Dong <dongxuyang@eswincomputing.com>
> + */
> +
> +#include <linux/auxiliary_bus.h>
> +#include <linux/device.h>
> +#include <linux/regmap.h>
> +#include <linux/reset-controller.h>
> +
> +#include <dt-bindings/reset/eswin,eic7700-hspcrg.h>
> +
> +/**
> + * struct eic7700_hsp_reset_data - reset controller information structure
> + * @rcdev: reset controller entity
> + * @regmap: regmap handle containing the memory-mapped reset registers
> + */
> +struct eic7700_hsp_reset_data {
> +	struct reset_controller_dev rcdev;
> +	struct regmap *regmap;
> +};
> +
> +struct eic7700_hsp_reg {
> +	u32 reg;
> +	u32 bit;
> +	bool active_low;
> +};
> +
> +static inline struct eic7700_hsp_reset_data *
> +to_eic7700_hsp_reset(struct reset_controller_dev *rcdev)
> +{
> +	return container_of(rcdev, struct eic7700_hsp_reset_data, rcdev);
> +}
> +
> +static const struct eic7700_hsp_reg eic7700_hsp_reset[] = {
> +	[EIC7700_HSP_RST_SATA_P0]	= {0x340, BIT(0), false},
> +	[EIC7700_HSP_RST_SATA_PHY]	= {0x340, BIT(1), false},
> +	[EIC7700_HSP_RST_USB0]		= {0x800, BIT(24), true},
> +	[EIC7700_HSP_RST_USB1]		= {0x900, BIT(24), true},
> +	[EIC7700_HSP_RST_USB0_PHY]	= {0x800, BIT(25), false},
> +	[EIC7700_HSP_RST_USB1_PHY]	= {0x900, BIT(25), false},
> +};
> +
> +static int eic7700_hsp_reset_assert(struct reset_controller_dev *rcdev,
> +				    unsigned long id)
> +{
> +	struct eic7700_hsp_reset_data *data = to_eic7700_hsp_reset(rcdev);
> +	int ret;
> +
> +	ret = regmap_assign_bits(data->regmap, eic7700_hsp_reset[id].reg,
> +				 eic7700_hsp_reset[id].bit,
> +				 !eic7700_hsp_reset[id].active_low);
> +
> +	return ret;

You can drop the temporary variable, just return
regmap_assign_bits(...) directly.

> +}
> +
> +static int eic7700_hsp_reset_deassert(struct reset_controller_dev *rcdev,
> +				      unsigned long id)
> +{
> +	struct eic7700_hsp_reset_data *data = to_eic7700_hsp_reset(rcdev);
> +	int ret;
> +
> +	ret = regmap_assign_bits(data->regmap, eic7700_hsp_reset[id].reg,
> +				 eic7700_hsp_reset[id].bit,
> +				 eic7700_hsp_reset[id].active_low);
> +
> +	return ret;
> +}
> +
> +static const struct reset_control_ops eic7700_hsp_reset_ops = {
> +	.assert = eic7700_hsp_reset_assert,
> +	.deassert = eic7700_hsp_reset_deassert,
> +};
> +
> +static int eic7700_hsp_reset_probe(struct auxiliary_device *adev,
> +				   const struct auxiliary_device_id *id)
> +{
> +	struct eic7700_hsp_reset_data *data;
> +	struct device *dev = &adev->dev;
> +
> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->regmap = dev_get_regmap(dev->parent, NULL);
> +	if (!data->regmap)
> +		return dev_err_probe(dev, -EINVAL, "failed to get regmap!\n");

-ENODEV seems to be more commonly used for this.

> +
> +	data->rcdev.owner = THIS_MODULE;
> +	data->rcdev.ops = &eic7700_hsp_reset_ops;
> +	data->rcdev.of_node = dev->parent->of_node;
> +	data->rcdev.dev = dev;
> +	data->rcdev.nr_resets = ARRAY_SIZE(eic7700_hsp_reset);
> +
> +	return devm_reset_controller_register(dev, &data->rcdev);
> +}
> +
> +static const struct auxiliary_device_id eic7700_hsp_reset_dt_ids[] = {

Drop the "_dt".

> +	{ .name = "clk_eic7700_hsp.hsp-reset", },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(auxiliary, eic7700_hsp_reset_dt_ids);
> +
> +static struct auxiliary_driver eic7700_hsp_reset_driver = {
> +	.probe	= eic7700_hsp_reset_probe,
> +	.id_table = eic7700_hsp_reset_dt_ids,
> +};
> +
> +module_auxiliary_driver(eic7700_hsp_reset_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Xuyang Dong <dongxuyang@eswincomputing.com>");
> +MODULE_DESCRIPTION("ESWIN EIC7700 HSP Reset Controller Driver");

With that,

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp