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

Brian Masney
2026-04-03T14:22:06Z

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@realtek.com>
> Co-developed-by: Yu-Chun Lin <eleanor.lin@realtek.com>
> Signed-off-by: Yu-Chun Lin <eleanor.lin@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@vger.kernel.org
> L: linux-clk@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@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