[PATCH v6 03/10] clk: realtek: Introduce a common probe()

[Brian Masney]

Hi Cheng-Yu,

On Thu, Apr 02, 2026 at 03:39:50PM +0800, Cheng-Yu Lee wrote:
> Add rtk_clk_probe() to set up the shared regmap, register clock hardware,
> and add the clock provider.
> 
> Additionally, if the "#reset-cells" property is present in the device tree,
> it creates and registers an auxiliary device using the provided aux_name.
> This allows the dedicated reset driver to bind to this device, enabling
> both clock and reset drivers to share the same regmap.
> 
> Signed-off-by: Cheng-Yu Lee <cylee12 at realtek.com>
> Co-developed-by: Yu-Chun Lin <eleanor.lin at realtek.com>
> Signed-off-by: Yu-Chun Lin <eleanor.lin at realtek.com>
> ---
> Changes in v6:
> - Replace direct reset controller initialization with auxiliary device creation.
> - Add aux_name parameter to rtk_clk_probe() to register the reset auxiliary device.
> - Simplify rtk_clk_desc because reset data is handled entirely by the auxiliary reset driver.
> - In Kconfig, change "depends on RESET_CONTROLLER" to "select RESET_CONTROLLER"
> - Remove unused includes headers and added <linux/auxiliary_bus.h>.
> ---
>  MAINTAINERS                  |  1 +
>  drivers/clk/Kconfig          |  1 +
>  drivers/clk/Makefile         |  1 +
>  drivers/clk/realtek/Kconfig  | 28 +++++++++++++++
>  drivers/clk/realtek/Makefile |  4 +++
>  drivers/clk/realtek/common.c | 67 ++++++++++++++++++++++++++++++++++++
>  drivers/clk/realtek/common.h | 37 ++++++++++++++++++++
>  7 files changed, 139 insertions(+)
>  create mode 100644 drivers/clk/realtek/Kconfig
>  create mode 100644 drivers/clk/realtek/Makefile
>  create mode 100644 drivers/clk/realtek/common.c
>  create mode 100644 drivers/clk/realtek/common.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 8f355896583b..8318156a02b5 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -22240,6 +22240,7 @@ L:	devicetree at vger.kernel.org
>  L:	linux-clk at vger.kernel.org
>  S:	Supported
>  F:	Documentation/devicetree/bindings/clock/realtek*
> +F:	drivers/clk/realtek/*
>  F:	drivers/reset/realtek/*
>  F:	include/dt-bindings/clock/realtek*
>  F:	include/dt-bindings/reset/realtek*
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 3d803b4cf5c1..d60f6415b0a3 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -519,6 +519,7 @@ source "drivers/clk/nuvoton/Kconfig"
>  source "drivers/clk/pistachio/Kconfig"
>  source "drivers/clk/qcom/Kconfig"
>  source "drivers/clk/ralink/Kconfig"
> +source "drivers/clk/realtek/Kconfig"
>  source "drivers/clk/renesas/Kconfig"
>  source "drivers/clk/rockchip/Kconfig"
>  source "drivers/clk/samsung/Kconfig"
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index f7bce3951a30..69b84d1e7bcc 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -140,6 +140,7 @@ obj-$(CONFIG_COMMON_CLK_PISTACHIO)	+= pistachio/
>  obj-$(CONFIG_COMMON_CLK_PXA)		+= pxa/
>  obj-$(CONFIG_COMMON_CLK_QCOM)		+= qcom/
>  obj-y					+= ralink/
> +obj-$(CONFIG_COMMON_CLK_REALTEK)	+= realtek/
>  obj-y					+= renesas/
>  obj-$(CONFIG_ARCH_ROCKCHIP)		+= rockchip/
>  obj-$(CONFIG_COMMON_CLK_SAMSUNG)	+= samsung/
> diff --git a/drivers/clk/realtek/Kconfig b/drivers/clk/realtek/Kconfig
> new file mode 100644
> index 000000000000..bc47d3f1c452
> --- /dev/null
> +++ b/drivers/clk/realtek/Kconfig
> @@ -0,0 +1,28 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +config COMMON_CLK_REALTEK
> +	bool "Clock driver for Realtek SoCs"
> +	depends on ARCH_REALTEK || COMPILE_TEST
> +	default ARCH_REALTEK
> +	help
> +	  Enable the common clock framework infrastructure for Realtek
> +	  system-on-chip platforms.
> +
> +	  This provides the base support required by individual Realtek
> +	  clock controller drivers to expose clocks to peripheral devices.
> +
> +	  If you have a Realtek-based platform, say Y.
> +
> +if COMMON_CLK_REALTEK
> +
> +config RTK_CLK_COMMON
> +	tristate "Realtek Clock Common"
> +	select RESET_CONTROLLER
> +	select RESET_RTK_COMMON

select AUXILIARY_BUS ?

> +	help
> +	  Common helper code shared by Realtek clock controller drivers.
> +
> +	  This provides utility functions and data structures used by
> +	  multiple Realtek clock implementations, and include integration
> +	  with reset controllers where required.
> +
> +endif
> diff --git a/drivers/clk/realtek/Makefile b/drivers/clk/realtek/Makefile
> new file mode 100644
> index 000000000000..377ec776ee47
> --- /dev/null
> +++ b/drivers/clk/realtek/Makefile
> @@ -0,0 +1,4 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +obj-$(CONFIG_RTK_CLK_COMMON) += clk-rtk.o
> +
> +clk-rtk-y += common.o
> diff --git a/drivers/clk/realtek/common.c b/drivers/clk/realtek/common.c
> new file mode 100644
> index 000000000000..c5aea15a3714
> --- /dev/null
> +++ b/drivers/clk/realtek/common.c
> @@ -0,0 +1,67 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2019 Realtek Semiconductor Corporation

If you are making changes here, should the copyrights be updated to
include 2026?

> + * Author: Cheng-Yu Lee <cylee12 at realtek.com>
> + */
> +
> +#include <linux/auxiliary_bus.h>
> +#include <linux/device.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include "common.h"
> +
> +static int rtk_reset_controller_register(struct device *dev, const char *aux_name)
> +{
> +	struct auxiliary_device *adev;
> +
> +	if (!of_property_present(dev->of_node, "#reset-cells"))
> +		return 0;
> +
> +	adev = devm_auxiliary_device_create(dev, aux_name, NULL);
> +
> +	if (IS_ERR(adev))
> +		return PTR_ERR(adev);
> +	return 0;

Add newline before return.

> +}
> +
> +int rtk_clk_probe(struct platform_device *pdev, const struct rtk_clk_desc *desc,
> +		  const char *aux_name)
> +{
> +	int i, ret;
> +	struct regmap *regmap;
> +	struct device *dev = &pdev->dev;

Put variables in reverse Christmas tree order.

> +
> +	regmap = device_node_to_regmap(pdev->dev.of_node);
> +	if (IS_ERR(regmap))
> +		return dev_err_probe(dev, PTR_ERR(regmap), "failed to get regmap\n");
> +
> +	for (i = 0; i < desc->num_clks; i++)
> +		desc->clks[i]->regmap = regmap;
> +
> +	for (i = 0; i < desc->clk_data->num; i++) {
> +		struct clk_hw *hw = desc->clk_data->hws[i];
> +
> +		if (!hw)
> +			continue;
> +
> +		ret = devm_clk_hw_register(dev, hw);
> +
> +		if (ret) {

Remove newline before if.

> +			dev_warn(dev, "failed to register hw of clk%d: %d\n", i,
> +				 ret);
> +			desc->clk_data->hws[i] = NULL;

This chunk doesn't take into account probe deferrals.

Brian