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

Yu-Chun Lin [林祐君]
2026-04-10T07:24:44Z

Hi Brian,

> 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 ?
>

Ack.

> > + 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?
>

Agreed. Will 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.
>

Ack.

> > +}
> > +
> > +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.
>

Ack.

> > +
> > + 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.
>

Ack.

> > + 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.

Will return error here.

Best Regards,
Yu-Chun

>
> Brian