Re: [PATCH v6 05/15] clk: starfive: Add JHB100 System-0 clock generator driver

[Jerome Brunet <jbrunet@baylibre.com>]

On mar. 13 oct. 2026 at 05:29, Changhuang Liang <changhuang.liang@starfivetech.com> wrote:

> Hi, Jerome
>
>> > Add support for JHB100 System-0 clock generator (SYS0CRG).
>> >
>> > Signed-off-by: Changhuang Liang <changhuang.liang@starfivetech.com>
>> > ---
>> >  MAINTAINERS                                   |   7 +
>> >  drivers/clk/starfive/Kconfig                  |  10 ++
>> >  drivers/clk/starfive/Makefile                 |   2 +
>> >  .../clk/starfive/clk-starfive-jhb100-sys0.c   | 156 ++++++++++++++++++
>> >  4 files changed, 175 insertions(+)
>> >  create mode 100644 drivers/clk/starfive/clk-starfive-jhb100-sys0.c
>> >
>> > diff --git a/MAINTAINERS b/MAINTAINERS index
>> > 66d6c15f1dd2..dff8b819f83e 100644
>> > --- a/MAINTAINERS
>> > +++ b/MAINTAINERS
>> > @@ -26217,6 +26217,13 @@ F:
>> 	Documentation/devicetree/bindings/phy/starfive,jh7110-usb-phy.yaml
>> >  F:	drivers/phy/starfive/phy-jh7110-pcie.c
>> >  F:	drivers/phy/starfive/phy-jh7110-usb.c
>> >
>> > +STARFIVE JHB100 CLOCK DRIVERS
>> > +M:	Changhuang Liang <changhuang.liang@starfivetech.com>
>> > +S:	Supported
>> > +F:	Documentation/devicetree/bindings/clock/starfive,jhb1*.yaml
>> > +F:	drivers/clk/starfive/clk-starfive-jhb1*
>> > +F:	include/dt-bindings/clock/starfive,jhb1*.h
>> > +
>> >  STARFIVE JHB100 EXTERNAL INTERRUPT CONTROLLER DRIVER
>> >  M:	Changhuang Liang <changhuang.liang@starfivetech.com>
>> >  S:	Supported
>> > diff --git a/drivers/clk/starfive/Kconfig
>> > b/drivers/clk/starfive/Kconfig index 51716655554f..cd5b7754403e 100644
>> > --- a/drivers/clk/starfive/Kconfig
>> > +++ b/drivers/clk/starfive/Kconfig
>> > @@ -72,3 +72,13 @@ config CLK_STARFIVE_JH7110_VOUT
>> >  	help
>> >  	  Say yes here to support the Video-Output clock controller
>> >  	  on the StarFive JH7110 SoC.
>> > +
>> > +config CLK_STARFIVE_JHB100_SYS0
>> > +	bool "StarFive JHB100 system-0 clock support"
>> > +	depends on ARCH_STARFIVE || COMPILE_TEST
>> > +	select CLK_STARFIVE_JH71X0
>> > +	select RESET_STARFIVE_JHB100 if RESET_CONTROLLER
>> 
>> just imply RESET_STARFIVE_JHB100 ?
>> 
>> It can be disabled if RESET_CONTROLLER is not set, so it is kind of weak
>> already.
>> 
>> > +	default ARCH_STARFIVE
>> > +	help
>> > +	  Say yes here to support the system-0 clock controller on the
>> > +	  StarFive JHB100 SoC.
>> > diff --git a/drivers/clk/starfive/Makefile
>> > b/drivers/clk/starfive/Makefile index 199ac0f37a2f..d2ba83d7d02c
>> > 100644
>> > --- a/drivers/clk/starfive/Makefile
>> > +++ b/drivers/clk/starfive/Makefile
>> > @@ -10,3 +10,5 @@ obj-$(CONFIG_CLK_STARFIVE_JH7110_AON)	+=
>> clk-starfive-jh7110-aon.o
>> >  obj-$(CONFIG_CLK_STARFIVE_JH7110_STG)	+= clk-starfive-jh7110-stg.o
>> >  obj-$(CONFIG_CLK_STARFIVE_JH7110_ISP)	+= clk-starfive-jh7110-isp.o
>> >  obj-$(CONFIG_CLK_STARFIVE_JH7110_VOUT)	+=
>> clk-starfive-jh7110-vout.o
>> > +
>> > +obj-$(CONFIG_CLK_STARFIVE_JHB100_SYS0)		+=
>> clk-starfive-jhb100-sys0.o
>> > diff --git a/drivers/clk/starfive/clk-starfive-jhb100-sys0.c
>> > b/drivers/clk/starfive/clk-starfive-jhb100-sys0.c
>> > new file mode 100644
>> > index 000000000000..edab54f228ad
>> > --- /dev/null
>> > +++ b/drivers/clk/starfive/clk-starfive-jhb100-sys0.c
>> > @@ -0,0 +1,156 @@
>> > +// SPDX-License-Identifier: GPL-2.0
>> > +/*
>> > + * StarFive JHB100 System-0 Clock Driver
>> > + *
>> > + * Copyright (C) 2024 StarFive Technology Co., Ltd.
>> > + *
>> > + * Author: Changhuang Liang <changhuang.liang@starfivetech.com>
>> > + *
>> > + */
>> > +
>> > +#include <dt-bindings/clock/starfive,jhb100-crg.h>
>> > +#include <linux/init.h>
>> > +#include <linux/platform_device.h>
>> > +
>> > +#include "clk-starfive-jh71x0.h"
>> > +
>> > +#define JHB100_SYS0CLK_NUM_CLKS
>> 	(JHB100_SYS0CLK_GPU1_NCNOC_INIT + 1)
>> > +
>> > +/* external clocks */
>> > +#define JHB100_SYS0CLK_OSC
>> 	(JHB100_SYS0CLK_NUM_CLKS + 0)
>> > +#define JHB100_SYS0CLK_PLL0
>> 	(JHB100_SYS0CLK_NUM_CLKS + 1)
>> > +#define JHB100_SYS0CLK_PLL1
>> 	(JHB100_SYS0CLK_NUM_CLKS + 2)
>> > +#define JHB100_SYS0CLK_PLL2
>> 	(JHB100_SYS0CLK_NUM_CLKS + 3)
>> 
>> Does this mean that if the you ever find out you've forgot an internal clock
>> (which does happen fairly often) the whole external block will shift ?
>> 
>
> Later, I will introduce the following macros to define the external clock, which can avoid this problem.
>
> #define JH71X0_EXT_CLK_FLAG	BIT(15)
> #define JH71X0_EXT_CLK(_n) 	(JH71X0_EXT_CLK_FLAG | (_n))
>

hummm okay ... still seems hackish to me.

>

-- 
Jerome