[PATCH v2 0/2] clk: ultrarisc: add DP1000 clock support

[PATCH v2 0/2] clk: ultrarisc: add DP1000 clock support

[Jia Wang via B4 Relay]

This series adds the devicetree binding and the clock driver for the
UltraRISC DP1000 SoC.

The clock tree is driven by a SYSPLL and provides fixed-factor clocks for
the subsystem and PCIe, divider-based root clocks for GMAC and the UART,
I2C, and SPI blocks, and per-instance gate clocks for UART0-3, I2C0-3,
and SPI0-1.

Testing:
- dt_binding_check and dtbs_check on ultrarisc,dp1000-clk
- Kernel build for RISC-V and boot-tested on DP1000
- Modules build test for CLK_ULTRARISC_DP1000

Signed-off-by: Jia Wang <wangjia@ultrarisc.com>
---
Changes in v2:
- Drop the redundant clock-names property from the clock binding.
- Move DP1000_CLK_NUM from the dt-bindings header into the driver.
- Clarify the divider load-bit handling in the common clock core.
- Validate that all advertised clock IDs are populated before registering
  the onecell clock provider.
- Rework divider composite clock registration so the driver builds
  correctly as a module.
- Link to v1: https://patch.msgid.link/20260611-ultrarisc-clock-v1-0-2d93ebb4cc13@ultrarisc.com

---
Jia Wang (2):
      dt-bindings: clock: ultrarisc: Add DP1000 Clock Controller
      clk: ultrarisc: add DP1000 clock driver

 .../bindings/clock/ultrarisc,dp1000-clk.yaml       |  60 +++
 MAINTAINERS                                        |   8 +
 drivers/clk/Kconfig                                |   1 +
 drivers/clk/Makefile                               |   1 +
 drivers/clk/ultrarisc/Kconfig                      |  18 +
 drivers/clk/ultrarisc/Makefile                     |   4 +
 drivers/clk/ultrarisc/clk-dp1000.c                 | 153 +++++++
 drivers/clk/ultrarisc/clk-ultrarisc.c              | 459 +++++++++++++++++++++
 drivers/clk/ultrarisc/clk-ultrarisc.h              |  73 ++++
 include/dt-bindings/clock/ultrarisc,dp1000-clk.h   |  27 ++
 10 files changed, 804 insertions(+)
---
base-commit: b1cbabe84ca1381a004fb91ee1791a1a53bce44e
change-id: 20260522-ultrarisc-clock-a1b7aa59f60b

Best regards,
--  
Jia Wang <wangjia@ultrarisc.com>

[PATCH v2 1/2] dt-bindings: clock: ultrarisc: Add DP1000 Clock Controller

[Jia Wang via B4 Relay]

From: Jia Wang <wangjia@ultrarisc.com>

Add doc for the clock controller on the UltraRISC DP1000 RISC-V SoC.

Signed-off-by: Jia Wang <wangjia@ultrarisc.com>
---
 .../bindings/clock/ultrarisc,dp1000-clk.yaml       | 60 ++++++++++++++++++++++
 MAINTAINERS                                        |  7 +++
 include/dt-bindings/clock/ultrarisc,dp1000-clk.h   | 27 ++++++++++
 3 files changed, 94 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/ultrarisc,dp1000-clk.yaml b/Documentation/devicetree/bindings/clock/ultrarisc,dp1000-clk.yaml
new file mode 100644
index 000000000000..ede565ec440c
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/ultrarisc,dp1000-clk.yaml
@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/ultrarisc,dp1000-clk.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: UltraRISC DP1000 Clock Controller
+
+maintainers:
+  - Jia Wang <wangjia@ultrarisc.com>
+
+description: |
+  The UltraRISC DP1000 clock controller is driven from a single external
+  oscillator input. It provides a system PLL with fractional multiplier
+  and post-divider stages, several fixed-ratio derived clocks for
+  the on-chip subsystem, Clock Configuration Register (CCR) divider
+  outputs for GMAC and the UART, I2C, and SPI root clocks, and
+  per-instance gate clocks for UART0-3, I2C0-3, and SPI0-1.
+
+  All available clocks are defined as preprocessor macros in
+  include/dt-bindings/clock/ultrarisc,dp1000-clk.h
+
+properties:
+  compatible:
+    const: ultrarisc,dp1000-clk
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+    description:
+      External oscillator input clock used as the parent of the PLLs.
+
+  "#clock-cells":
+    const: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - "#clock-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/ultrarisc,dp1000-clk.h>
+
+    soc {
+      #address-cells = <2>;
+      #size-cells = <2>;
+
+      clock-controller@11080000 {
+        compatible = "ultrarisc,dp1000-clk";
+        reg = <0x0 0x11080000 0x0 0x1000>;
+        clocks = <&osc>;
+        #clock-cells = <1>;
+      };
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index 3d6db8cb608f..b7e43313c65f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -27439,6 +27439,13 @@ S:	Maintained
 F:	drivers/usb/common/ulpi.c
 F:	include/linux/ulpi/
 
+ULTRARISC DP1000 CLOCK DRIVER
+M:	Jia Wang <wangjia@ultrarisc.com>
+L:	linux-clk@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/clock/ultrarisc,dp1000-clk.yaml
+F:	include/dt-bindings/clock/ultrarisc,dp1000-clk.h
+
 ULTRATRONIK BOARD SUPPORT
 M:	Goran Rađenović <goran.radni@gmail.com>
 M:	Börge Strümpfel <boerge.struempfel@gmail.com>
diff --git a/include/dt-bindings/clock/ultrarisc,dp1000-clk.h b/include/dt-bindings/clock/ultrarisc,dp1000-clk.h
new file mode 100644
index 000000000000..751125f99965
--- /dev/null
+++ b/include/dt-bindings/clock/ultrarisc,dp1000-clk.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+#ifndef _DT_BINDINGS_CLOCK_ULTRARISC_DP1000_CLK_H
+#define _DT_BINDINGS_CLOCK_ULTRARISC_DP1000_CLK_H
+
+#define DP1000_CLK_SYSPLL		0
+#define DP1000_CLK_SYSPLL_DIV2		1
+#define DP1000_CLK_SUBSYS		2
+#define DP1000_CLK_GMAC			3
+#define DP1000_CLK_UART_ROOT		4
+#define DP1000_CLK_I2C_ROOT		5
+#define DP1000_CLK_SPI_ROOT		6
+#define DP1000_CLK_PCIE_DBI		7
+#define DP1000_CLK_PCIEX4_CORE		8
+#define DP1000_CLK_PCIEX16_CORE		9
+#define DP1000_CLK_PCIE_AUX		10
+#define DP1000_CLK_UART0		11
+#define DP1000_CLK_UART1		12
+#define DP1000_CLK_UART2		13
+#define DP1000_CLK_UART3		14
+#define DP1000_CLK_I2C0			15
+#define DP1000_CLK_I2C1			16
+#define DP1000_CLK_I2C2			17
+#define DP1000_CLK_I2C3			18
+#define DP1000_CLK_SPI0			19
+#define DP1000_CLK_SPI1			20
+
+#endif /* _DT_BINDINGS_CLOCK_ULTRARISC_DP1000_CLK_H */

-- 
2.34.1

Re: [PATCH v2 1/2] dt-bindings: clock: ultrarisc: Add DP1000 Clock Controller

[Conor Dooley]

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On Wed, Jun 17, 2026 at 02:02:54PM +0800, Jia Wang via B4 Relay wrote:
> From: Jia Wang <wangjia@ultrarisc.com>
> 
> Add doc for the clock controller on the UltraRISC DP1000 RISC-V SoC.
> 
> Signed-off-by: Jia Wang <wangjia@ultrarisc.com>

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
pw-bot: not-applicable

Cheers,
Conor.

> ---
>  .../bindings/clock/ultrarisc,dp1000-clk.yaml       | 60 ++++++++++++++++++++++
>  MAINTAINERS                                        |  7 +++
>  include/dt-bindings/clock/ultrarisc,dp1000-clk.h   | 27 ++++++++++
>  3 files changed, 94 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/clock/ultrarisc,dp1000-clk.yaml b/Documentation/devicetree/bindings/clock/ultrarisc,dp1000-clk.yaml
> new file mode 100644
> index 000000000000..ede565ec440c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/ultrarisc,dp1000-clk.yaml
> @@ -0,0 +1,60 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/clock/ultrarisc,dp1000-clk.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: UltraRISC DP1000 Clock Controller
> +
> +maintainers:
> +  - Jia Wang <wangjia@ultrarisc.com>
> +
> +description: |
> +  The UltraRISC DP1000 clock controller is driven from a single external
> +  oscillator input. It provides a system PLL with fractional multiplier
> +  and post-divider stages, several fixed-ratio derived clocks for
> +  the on-chip subsystem, Clock Configuration Register (CCR) divider
> +  outputs for GMAC and the UART, I2C, and SPI root clocks, and
> +  per-instance gate clocks for UART0-3, I2C0-3, and SPI0-1.
> +
> +  All available clocks are defined as preprocessor macros in
> +  include/dt-bindings/clock/ultrarisc,dp1000-clk.h
> +
> +properties:
> +  compatible:
> +    const: ultrarisc,dp1000-clk
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +    description:
> +      External oscillator input clock used as the parent of the PLLs.
> +
> +  "#clock-cells":
> +    const: 1
> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +  - "#clock-cells"
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/ultrarisc,dp1000-clk.h>
> +
> +    soc {
> +      #address-cells = <2>;
> +      #size-cells = <2>;
> +
> +      clock-controller@11080000 {
> +        compatible = "ultrarisc,dp1000-clk";
> +        reg = <0x0 0x11080000 0x0 0x1000>;
> +        clocks = <&osc>;
> +        #clock-cells = <1>;
> +      };
> +    };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 3d6db8cb608f..b7e43313c65f 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -27439,6 +27439,13 @@ S:	Maintained
>  F:	drivers/usb/common/ulpi.c
>  F:	include/linux/ulpi/
>  
> +ULTRARISC DP1000 CLOCK DRIVER
> +M:	Jia Wang <wangjia@ultrarisc.com>
> +L:	linux-clk@vger.kernel.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/clock/ultrarisc,dp1000-clk.yaml
> +F:	include/dt-bindings/clock/ultrarisc,dp1000-clk.h
> +
>  ULTRATRONIK BOARD SUPPORT
>  M:	Goran Rađenović <goran.radni@gmail.com>
>  M:	Börge Strümpfel <boerge.struempfel@gmail.com>
> diff --git a/include/dt-bindings/clock/ultrarisc,dp1000-clk.h b/include/dt-bindings/clock/ultrarisc,dp1000-clk.h
> new file mode 100644
> index 000000000000..751125f99965
> --- /dev/null
> +++ b/include/dt-bindings/clock/ultrarisc,dp1000-clk.h
> @@ -0,0 +1,27 @@
> +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
> +#ifndef _DT_BINDINGS_CLOCK_ULTRARISC_DP1000_CLK_H
> +#define _DT_BINDINGS_CLOCK_ULTRARISC_DP1000_CLK_H
> +
> +#define DP1000_CLK_SYSPLL		0
> +#define DP1000_CLK_SYSPLL_DIV2		1
> +#define DP1000_CLK_SUBSYS		2
> +#define DP1000_CLK_GMAC			3
> +#define DP1000_CLK_UART_ROOT		4
> +#define DP1000_CLK_I2C_ROOT		5
> +#define DP1000_CLK_SPI_ROOT		6
> +#define DP1000_CLK_PCIE_DBI		7
> +#define DP1000_CLK_PCIEX4_CORE		8
> +#define DP1000_CLK_PCIEX16_CORE		9
> +#define DP1000_CLK_PCIE_AUX		10
> +#define DP1000_CLK_UART0		11
> +#define DP1000_CLK_UART1		12
> +#define DP1000_CLK_UART2		13
> +#define DP1000_CLK_UART3		14
> +#define DP1000_CLK_I2C0			15
> +#define DP1000_CLK_I2C1			16
> +#define DP1000_CLK_I2C2			17
> +#define DP1000_CLK_I2C3			18
> +#define DP1000_CLK_SPI0			19
> +#define DP1000_CLK_SPI1			20
> +
> +#endif /* _DT_BINDINGS_CLOCK_ULTRARISC_DP1000_CLK_H */
> 
> -- 
> 2.34.1
> 
> 
> 

[-- Attachment #2: signature.asc --]
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Re: [PATCH v2 1/2] dt-bindings: clock: ultrarisc: Add DP1000 Clock Controller

[Brian Masney]

Hi Krzysztof / Conor,

On Wed, Jun 17, 2026 at 02:02:54PM +0800, Jia Wang wrote:
> diff --git a/include/dt-bindings/clock/ultrarisc,dp1000-clk.h b/include/dt-bindings/clock/ultrarisc,dp1000-clk.h
> new file mode 100644
> index 000000000000..751125f99965
> --- /dev/null
> +++ b/include/dt-bindings/clock/ultrarisc,dp1000-clk.h
> @@ -0,0 +1,27 @@
> +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
> +#ifndef _DT_BINDINGS_CLOCK_ULTRARISC_DP1000_CLK_H
> +#define _DT_BINDINGS_CLOCK_ULTRARISC_DP1000_CLK_H
> +
> +#define DP1000_CLK_SYSPLL		0
> +#define DP1000_CLK_SYSPLL_DIV2		1
> +#define DP1000_CLK_SUBSYS		2
> +#define DP1000_CLK_GMAC			3
> +#define DP1000_CLK_UART_ROOT		4
> +#define DP1000_CLK_I2C_ROOT		5
> +#define DP1000_CLK_SPI_ROOT		6
> +#define DP1000_CLK_PCIE_DBI		7
> +#define DP1000_CLK_PCIEX4_CORE		8
> +#define DP1000_CLK_PCIEX16_CORE		9
> +#define DP1000_CLK_PCIE_AUX		10
> +#define DP1000_CLK_UART0		11
> +#define DP1000_CLK_UART1		12
> +#define DP1000_CLK_UART2		13
> +#define DP1000_CLK_UART3		14
> +#define DP1000_CLK_I2C0			15
> +#define DP1000_CLK_I2C1			16
> +#define DP1000_CLK_I2C2			17
> +#define DP1000_CLK_I2C3			18
> +#define DP1000_CLK_SPI0			19
> +#define DP1000_CLK_SPI1			20

A common scenario for the driver side is that it needs to know how many
clocks are present. For example, the driver in this series has the
following in drivers/clk/ultrarisc/clk-dp1000.c:

    #define DP1000_CLK_NUM                       21

Which seems a bit fragile to me having it in a separate file.

I've seen where some dt-bindings will have the define right below the
last clock, so DP1000_CLK_SPI1 in this particular case.

There are a few clock dt-bindings that have it this way. For example,
see include/dt-bindings/clock/nuvoton,npcm7xx-clock.h. Personally, I
prefer it this way, however I can see where the argument could be made
that this doesn't belong in the dt-bindings.

Do you have guidance for what you'd like to see?

Brian

[PATCH v2 2/2] clk: ultrarisc: add DP1000 clock driver

[Jia Wang via B4 Relay]

From: Jia Wang <wangjia@ultrarisc.com>

Add a clock driver for the UltraRISC DP1000 SoC.

The clock tree is driven by a SYSPLL and provides fixed-factor clocks for
the subsystem and PCIe, divider-based root clocks for GMAC and the UART,
I2C, and SPI blocks, and per-instance gate clocks for UART0-3, I2C0-3,
and SPI0-1.

Signed-off-by: Jia Wang <wangjia@ultrarisc.com>
---
 MAINTAINERS                           |   1 +
 drivers/clk/Kconfig                   |   1 +
 drivers/clk/Makefile                  |   1 +
 drivers/clk/ultrarisc/Kconfig         |  18 ++
 drivers/clk/ultrarisc/Makefile        |   4 +
 drivers/clk/ultrarisc/clk-dp1000.c    | 153 ++++++++++++
 drivers/clk/ultrarisc/clk-ultrarisc.c | 459 ++++++++++++++++++++++++++++++++++
 drivers/clk/ultrarisc/clk-ultrarisc.h |  73 ++++++
 8 files changed, 710 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index b7e43313c65f..aa5021f30cb5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -27444,6 +27444,7 @@ M:	Jia Wang <wangjia@ultrarisc.com>
 L:	linux-clk@vger.kernel.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/clock/ultrarisc,dp1000-clk.yaml
+F:	drivers/clk/ultrarisc/*
 F:	include/dt-bindings/clock/ultrarisc,dp1000-clk.h
 
 ULTRATRONIK BOARD SUPPORT
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index b2efbe9f6acb..75e336858420 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -535,6 +535,7 @@ source "drivers/clk/tenstorrent/Kconfig"
 source "drivers/clk/thead/Kconfig"
 source "drivers/clk/stm32/Kconfig"
 source "drivers/clk/ti/Kconfig"
+source "drivers/clk/ultrarisc/Kconfig"
 source "drivers/clk/uniphier/Kconfig"
 source "drivers/clk/visconti/Kconfig"
 source "drivers/clk/x86/Kconfig"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index a3e2862ebd7e..891272e8e1da 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -158,6 +158,7 @@ obj-$(CONFIG_ARCH_TEGRA)		+= tegra/
 obj-y					+= tenstorrent/
 obj-$(CONFIG_ARCH_THEAD)		+= thead/
 obj-y					+= ti/
+obj-y					+= ultrarisc/
 obj-$(CONFIG_CLK_UNIPHIER)		+= uniphier/
 obj-$(CONFIG_ARCH_U8500)		+= ux500/
 obj-y					+= versatile/
diff --git a/drivers/clk/ultrarisc/Kconfig b/drivers/clk/ultrarisc/Kconfig
new file mode 100644
index 000000000000..2eecc6ac3119
--- /dev/null
+++ b/drivers/clk/ultrarisc/Kconfig
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config CLK_ULTRARISC
+	tristate
+	depends on OF
+	depends on ARCH_ULTRARISC || COMPILE_TEST
+
+config CLK_ULTRARISC_DP1000
+	tristate "UltraRISC DP1000 clock controller"
+	select CLK_ULTRARISC
+	depends on OF && HAS_IOMEM
+	depends on ARCH_ULTRARISC || COMPILE_TEST
+	default ARCH_ULTRARISC
+	help
+	  This driver provides the clock controller for the UltraRISC
+	  DP1000 SoC. It exposes the PLL output, derived fixed-factor
+	  clocks, programmable divider clocks, and peripheral gate
+	  clocks to Linux consumers.
diff --git a/drivers/clk/ultrarisc/Makefile b/drivers/clk/ultrarisc/Makefile
new file mode 100644
index 000000000000..b013708c9444
--- /dev/null
+++ b/drivers/clk/ultrarisc/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_CLK_ULTRARISC) += clk-ultrarisc.o
+obj-$(CONFIG_CLK_ULTRARISC_DP1000) += clk-dp1000.o
diff --git a/drivers/clk/ultrarisc/clk-dp1000.c b/drivers/clk/ultrarisc/clk-dp1000.c
new file mode 100644
index 000000000000..33a16df8f189
--- /dev/null
+++ b/drivers/clk/ultrarisc/clk-dp1000.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2026 UltraRISC Technology (Shanghai) Co., Ltd.
+ */
+
+#include <linux/module.h>
+
+#include <dt-bindings/clock/ultrarisc,dp1000-clk.h>
+
+#include "clk-ultrarisc.h"
+
+#define DP1000_PLL_CFG1_OFFSET		0x400
+#define DP1000_PLL_CFG2_OFFSET		0x404
+
+#define DP1000_CCR_UART_OFFSET		0x220
+#define DP1000_CCR_I2C_OFFSET		0x224
+#define DP1000_CCR_GMAC_OFFSET		0x228
+#define DP1000_CCR_SPI_OFFSET		0x22c
+#define DP1000_PERI_CLKENA_OFFSET	0x270
+
+#define DP1000_CCR_LOAD			BIT(16)
+
+#define DP1000_PERI_MAX_RATE		62500000UL
+#define DP1000_CLK_NUM			21
+
+static const struct ultrarisc_pll_layout dp1000_pll_layout = {
+	.cfg1_offset = DP1000_PLL_CFG1_OFFSET,
+	.cfg2_offset = DP1000_PLL_CFG2_OFFSET,
+	.frac_mask = GENMASK(23, 0),
+	.m_mask = GENMASK(23, 16),
+	.n_mask = GENMASK(11, 6),
+	.oddiv1_mask = GENMASK(4, 3),
+	.oddiv2_mask = GENMASK(1, 0),
+};
+
+static const struct ultrarisc_pll_desc dp1000_plls[] = {
+	{
+		.id = DP1000_CLK_SYSPLL,
+		.name = "syspll_clk",
+	},
+};
+
+#define DP1000_FIXED_FACTOR(_id, _name, _parent, _mult, _div)	\
+	{							\
+		.id = (_id),					\
+		.name = (_name),				\
+		.parent_id = (_parent),				\
+		.mult = (_mult),				\
+		.div = (_div),					\
+	}
+
+#define DP1000_DIV(_id, _name, _offset, _parent, _max_rate)	\
+	{							\
+		.id = (_id),					\
+		.name = (_name),				\
+		.offset = (_offset),				\
+		.parent_id = (_parent),				\
+		.max_rate = (_max_rate),			\
+		.load_mask = DP1000_CCR_LOAD,			\
+		.div_shift = 8,					\
+		.div_width = 4,					\
+		.gate_bit = 0,					\
+		.divider_flags = CLK_DIVIDER_ONE_BASED,		\
+		.gate_flags = 0,				\
+	}
+
+#define DP1000_GATE(_id, _name, _parent, _bit)		\
+	{							\
+		.id = (_id),					\
+		.name = (_name),				\
+		.offset = DP1000_PERI_CLKENA_OFFSET,		\
+		.parent_id = (_parent),				\
+		.gate_bit = (_bit),				\
+		.gate_flags = 0,				\
+	}
+
+static const struct ultrarisc_fixed_factor_desc dp1000_fixed_factor_clks[] = {
+	DP1000_FIXED_FACTOR(DP1000_CLK_SYSPLL_DIV2, "syspll_div2_clk",
+			    DP1000_CLK_SYSPLL, 1, 2),
+	DP1000_FIXED_FACTOR(DP1000_CLK_SUBSYS, "subsys_clk",
+			    DP1000_CLK_SYSPLL_DIV2, 1, 2),
+	DP1000_FIXED_FACTOR(DP1000_CLK_PCIE_DBI, "pcie_dbi_clk",
+			    DP1000_CLK_SYSPLL, 1, 10),
+	DP1000_FIXED_FACTOR(DP1000_CLK_PCIEX4_CORE, "pciex4_core_clk",
+			    DP1000_CLK_SYSPLL, 1, 2),
+	DP1000_FIXED_FACTOR(DP1000_CLK_PCIEX16_CORE, "pciex16_core_clk",
+			    DP1000_CLK_SYSPLL, 1, 1),
+	DP1000_FIXED_FACTOR(DP1000_CLK_PCIE_AUX, "pcie_aux_clk",
+			    DP1000_CLK_SYSPLL, 1, 40),
+};
+
+static const struct ultrarisc_divider_desc dp1000_divider_clks[] = {
+	DP1000_DIV(DP1000_CLK_GMAC, "gmac_clk", DP1000_CCR_GMAC_OFFSET,
+		   DP1000_CLK_SYSPLL_DIV2, 0),
+	DP1000_DIV(DP1000_CLK_UART_ROOT, "uart_root_clk",
+		   DP1000_CCR_UART_OFFSET, DP1000_CLK_SUBSYS,
+		   DP1000_PERI_MAX_RATE),
+	DP1000_DIV(DP1000_CLK_I2C_ROOT, "i2c_root_clk",
+		   DP1000_CCR_I2C_OFFSET, DP1000_CLK_SUBSYS,
+		   DP1000_PERI_MAX_RATE),
+	DP1000_DIV(DP1000_CLK_SPI_ROOT, "spi_root_clk",
+		   DP1000_CCR_SPI_OFFSET, DP1000_CLK_SUBSYS,
+		   DP1000_PERI_MAX_RATE),
+};
+
+static const struct ultrarisc_gate_desc dp1000_gate_clks[] = {
+	DP1000_GATE(DP1000_CLK_UART0, "uart0_clk", DP1000_CLK_UART_ROOT, 0),
+	DP1000_GATE(DP1000_CLK_UART1, "uart1_clk", DP1000_CLK_UART_ROOT, 1),
+	DP1000_GATE(DP1000_CLK_UART2, "uart2_clk", DP1000_CLK_UART_ROOT, 2),
+	DP1000_GATE(DP1000_CLK_UART3, "uart3_clk", DP1000_CLK_UART_ROOT, 3),
+	DP1000_GATE(DP1000_CLK_I2C0, "i2c0_clk", DP1000_CLK_I2C_ROOT, 4),
+	DP1000_GATE(DP1000_CLK_I2C1, "i2c1_clk", DP1000_CLK_I2C_ROOT, 5),
+	DP1000_GATE(DP1000_CLK_I2C2, "i2c2_clk", DP1000_CLK_I2C_ROOT, 6),
+	DP1000_GATE(DP1000_CLK_I2C3, "i2c3_clk", DP1000_CLK_I2C_ROOT, 7),
+	DP1000_GATE(DP1000_CLK_SPI0, "spi0_clk", DP1000_CLK_SPI_ROOT, 8),
+	DP1000_GATE(DP1000_CLK_SPI1, "spi1_clk", DP1000_CLK_SPI_ROOT, 9),
+};
+
+static const struct ultrarisc_clk_soc_data dp1000_clk_soc_data = {
+	.num_clks = DP1000_CLK_NUM,
+	.pll_layout = &dp1000_pll_layout,
+	.plls = dp1000_plls,
+	.num_plls = ARRAY_SIZE(dp1000_plls),
+	.fixed_factors = dp1000_fixed_factor_clks,
+	.num_fixed_factors = ARRAY_SIZE(dp1000_fixed_factor_clks),
+	.dividers = dp1000_divider_clks,
+	.num_dividers = ARRAY_SIZE(dp1000_divider_clks),
+	.gates = dp1000_gate_clks,
+	.num_gates = ARRAY_SIZE(dp1000_gate_clks),
+};
+
+static int dp1000_clk_probe(struct platform_device *pdev)
+{
+	return ultrarisc_clk_probe(pdev, &dp1000_clk_soc_data);
+}
+
+static const struct of_device_id dp1000_clk_of_match[] = {
+	{ .compatible = "ultrarisc,dp1000-clk" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, dp1000_clk_of_match);
+
+static struct platform_driver dp1000_clk_driver = {
+	.probe = dp1000_clk_probe,
+	.driver = {
+		.name = "ultrarisc-dp1000-clk",
+		.of_match_table = dp1000_clk_of_match,
+	},
+};
+module_platform_driver(dp1000_clk_driver);
+
+MODULE_DESCRIPTION("UltraRISC DP1000 clock controller");
+MODULE_LICENSE("GPL");
diff --git a/drivers/clk/ultrarisc/clk-ultrarisc.c b/drivers/clk/ultrarisc/clk-ultrarisc.c
new file mode 100644
index 000000000000..4ef222348dd7
--- /dev/null
+++ b/drivers/clk/ultrarisc/clk-ultrarisc.c
@@ -0,0 +1,459 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2026 UltraRISC Technology (Shanghai) Co., Ltd.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/of_clk.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "clk-ultrarisc.h"
+
+struct ultrarisc_pll_clk {
+	struct clk_hw hw;
+	void __iomem *base;
+	const struct ultrarisc_pll_layout *layout;
+};
+
+struct ultrarisc_divider_clk {
+	struct clk_divider divider;
+	struct clk_gate gate;
+	u32 load_mask;
+};
+
+#define to_ultrarisc_pll_clk(_hw) \
+	container_of(_hw, struct ultrarisc_pll_clk, hw)
+
+static inline struct ultrarisc_divider_clk *
+to_ultrarisc_divider_clk(struct clk_hw *hw)
+{
+	struct clk_divider *divider = to_clk_divider(hw);
+
+	return container_of(divider, struct ultrarisc_divider_clk, divider);
+}
+
+static unsigned long ultrarisc_pll_recalc_rate(struct clk_hw *hw,
+					       unsigned long parent_rate)
+{
+	struct ultrarisc_pll_clk *pll = to_ultrarisc_pll_clk(hw);
+	const struct ultrarisc_pll_layout *layout = pll->layout;
+	u32 oddiv1_div, oddiv2_div;
+	u64 mult, rate, den;
+	u32 frac, m, n;
+	u32 cfg1, cfg2;
+
+	cfg1 = readl_relaxed(pll->base + layout->cfg1_offset);
+	cfg2 = readl_relaxed(pll->base + layout->cfg2_offset);
+
+	frac = field_get(layout->frac_mask, cfg1);
+	m = field_get(layout->m_mask, cfg2);
+	n = field_get(layout->n_mask, cfg2);
+	oddiv1_div = 1U << field_get(layout->oddiv1_mask, cfg2);
+	oddiv2_div = 1U << field_get(layout->oddiv2_mask, cfg2);
+
+	if (!n)
+		return 0;
+
+	/*
+	 * The output frequency is calculated as:
+	 * fvco = parent * (m + frac / 2^24) / n
+	 * fout = fvco / (2^oddiv1_raw * 2^oddiv2_raw)
+	 *
+	 * The output divider values are derived from the raw register field
+	 * values as:
+	 * oddivX_div = 1 << oddivX_raw
+	 */
+	mult = ((u64)m << 24) + frac;
+	rate = (u64)parent_rate * mult;
+	den = ((u64)n << 24) * oddiv1_div * oddiv2_div;
+
+	return div64_u64(rate + (den >> 1), den);
+}
+
+static const struct clk_ops ultrarisc_pll_ro_ops = {
+	.recalc_rate = ultrarisc_pll_recalc_rate,
+};
+
+static unsigned long
+ultrarisc_divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
+{
+	struct clk_divider *divider = to_clk_divider(hw);
+	u32 val;
+
+	val = readl_relaxed(divider->reg) >> divider->shift;
+	val &= clk_div_mask(divider->width);
+
+	return divider_recalc_rate(hw, parent_rate, val, divider->table,
+				   divider->flags, divider->width);
+}
+
+static int ultrarisc_divider_determine_rate(struct clk_hw *hw,
+					    struct clk_rate_request *req)
+{
+	struct clk_divider *divider = to_clk_divider(hw);
+
+	return divider_determine_rate(hw, req, divider->table, divider->width,
+				      divider->flags);
+}
+
+static int ultrarisc_divider_set_rate(struct clk_hw *hw, unsigned long rate,
+				      unsigned long parent_rate)
+{
+	struct ultrarisc_divider_clk *divider_clk = to_ultrarisc_divider_clk(hw);
+	struct clk_divider *divider = &divider_clk->divider;
+	int value;
+	u32 val;
+
+	value = divider_get_val(rate, parent_rate, divider->table,
+				divider->width, divider->flags);
+	if (value < 0)
+		return value;
+
+	scoped_guard(spinlock_irqsave, divider->lock) {
+		val = readl_relaxed(divider->reg);
+		val &= ~(clk_div_mask(divider->width) << divider->shift);
+		val |= value << divider->shift;
+		writel_relaxed(val, divider->reg);
+
+		if (divider_clk->load_mask) {
+			/*
+			 * Program the new divider field, then write 1 to the
+			 * load bit to trigger the update. The load bit is
+			 * write-triggered and reads back as 0 on this hardware.
+			 */
+			writel_relaxed(val | divider_clk->load_mask,
+				       divider->reg);
+		}
+	}
+
+	return 0;
+}
+
+static const struct clk_ops ultrarisc_divider_ops = {
+	.recalc_rate = ultrarisc_divider_recalc_rate,
+	.determine_rate = ultrarisc_divider_determine_rate,
+	.set_rate = ultrarisc_divider_set_rate,
+};
+
+static void ultrarisc_clk_unregister_composite(void *data)
+{
+	clk_hw_unregister_composite(data);
+}
+
+static struct clk_hw *
+ultrarisc_clk_hw_register_composite(struct device *dev, const char *name,
+				    const char * const *parent_names,
+				    int num_parents, struct clk_hw *mux_hw,
+				    const struct clk_ops *mux_ops,
+				    struct clk_hw *rate_hw,
+				    const struct clk_ops *rate_ops,
+				    struct clk_hw *gate_hw,
+				    const struct clk_ops *gate_ops,
+				    unsigned long flags)
+{
+	struct clk_hw *hw;
+	int ret;
+
+	hw = clk_hw_register_composite(dev, name, parent_names, num_parents,
+				       mux_hw, mux_ops, rate_hw, rate_ops,
+				       gate_hw, gate_ops, flags);
+	if (IS_ERR(hw))
+		return hw;
+
+	ret = devm_add_action_or_reset(dev, ultrarisc_clk_unregister_composite,
+				       hw);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return hw;
+}
+
+static struct clk_hw *ultrarisc_clk_register_pll(struct device *dev,
+						 const struct ultrarisc_pll_desc *desc,
+						 const struct ultrarisc_pll_layout *layout,
+						 void __iomem *base)
+{
+	struct clk_parent_data pdata = { .index = 0 };
+	struct ultrarisc_pll_clk *pll;
+	struct clk_init_data init = {
+		.name = desc->name,
+		.ops = &ultrarisc_pll_ro_ops,
+		.parent_data = &pdata,
+		.num_parents = 1,
+		.flags = CLK_GET_RATE_NOCACHE,
+	};
+	int ret;
+
+	pll = devm_kzalloc(dev, sizeof(*pll), GFP_KERNEL);
+	if (!pll)
+		return ERR_PTR(-ENOMEM);
+
+	pll->base = base;
+	pll->layout = layout;
+	pll->hw.init = &init;
+
+	ret = devm_clk_hw_register(dev, &pll->hw);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return &pll->hw;
+}
+
+static struct clk_hw *
+ultrarisc_clk_register_divider(struct device *dev,
+			       const struct ultrarisc_divider_desc *desc,
+			       struct clk_hw *parent_hw, void __iomem *base,
+			       spinlock_t *lock)
+{
+	const char * const parent_names[] = { clk_hw_get_name(parent_hw) };
+	void __iomem *reg = base + desc->offset;
+	struct ultrarisc_divider_clk *divider;
+	const struct clk_ops *gate_ops = NULL;
+	struct clk_hw *gate_hw = NULL;
+
+	if (!desc->div_width)
+		return ERR_PTR(-EINVAL);
+
+	if (!lock)
+		return ERR_PTR(-EINVAL);
+
+	divider = devm_kzalloc(dev, sizeof(*divider), GFP_KERNEL);
+	if (!divider)
+		return ERR_PTR(-ENOMEM);
+
+	divider->divider.reg = reg;
+	divider->divider.shift = desc->div_shift;
+	divider->divider.width = desc->div_width;
+	divider->divider.flags = desc->divider_flags;
+	divider->divider.lock = lock;
+	divider->load_mask = desc->load_mask;
+
+	if (desc->gate_bit != ULTRARISC_CLK_NO_GATE) {
+		divider->gate.reg = reg;
+		divider->gate.bit_idx = desc->gate_bit;
+		divider->gate.flags = desc->gate_flags;
+		divider->gate.lock = lock;
+		gate_hw = &divider->gate.hw;
+		gate_ops = &clk_gate_ops;
+	}
+
+	return ultrarisc_clk_hw_register_composite(dev, desc->name,
+						   parent_names, 1,
+						   NULL, NULL,
+						   &divider->divider.hw,
+						   &ultrarisc_divider_ops,
+						   gate_hw, gate_ops,
+						   CLK_GET_RATE_NOCACHE);
+}
+
+static int ultrarisc_clk_register_fixed_factors(struct device *dev,
+						struct clk_hw_onecell_data *clk_data,
+						const struct ultrarisc_clk_soc_data *soc_data)
+{
+	u32 i;
+
+	for (i = 0; i < soc_data->num_fixed_factors; i++) {
+		const struct ultrarisc_fixed_factor_desc *desc;
+		struct clk_hw *parent_hw;
+		struct clk_hw *hw;
+
+		desc = &soc_data->fixed_factors[i];
+		if (desc->id >= clk_data->num ||
+		    desc->parent_id >= clk_data->num)
+			return -EINVAL;
+
+		parent_hw = clk_data->hws[desc->parent_id];
+		if (!parent_hw)
+			return -EINVAL;
+
+		hw = devm_clk_hw_register_fixed_factor_parent_hw(dev, desc->name,
+								 parent_hw,
+								 CLK_GET_RATE_NOCACHE,
+								 desc->mult,
+								 desc->div);
+		if (IS_ERR(hw))
+			return PTR_ERR(hw);
+
+		clk_data->hws[desc->id] = hw;
+	}
+
+	return 0;
+}
+
+static int ultrarisc_clk_register_plls(struct platform_device *pdev,
+				       struct clk_hw_onecell_data *clk_data,
+				       const struct ultrarisc_clk_soc_data *soc_data,
+				       void __iomem *base)
+{
+	struct device *dev = &pdev->dev;
+	u32 i;
+
+	for (i = 0; i < soc_data->num_plls; i++) {
+		const struct ultrarisc_pll_desc *desc = &soc_data->plls[i];
+		struct clk_hw *hw;
+
+		if (desc->id >= clk_data->num)
+			return -EINVAL;
+
+		hw = ultrarisc_clk_register_pll(dev, desc, soc_data->pll_layout,
+						base);
+		if (IS_ERR(hw))
+			return PTR_ERR(hw);
+
+		clk_data->hws[desc->id] = hw;
+	}
+
+	return 0;
+}
+
+static int ultrarisc_clk_register_dividers(struct platform_device *pdev,
+					   struct clk_hw_onecell_data *clk_data,
+					   const struct ultrarisc_clk_soc_data *soc_data,
+					   void __iomem *base,
+					   spinlock_t *lock)
+{
+	struct device *dev = &pdev->dev;
+	u32 i;
+
+	for (i = 0; i < soc_data->num_dividers; i++) {
+		const struct ultrarisc_divider_desc *desc;
+		struct clk_hw *parent_hw;
+		struct clk_hw *hw;
+
+		desc = &soc_data->dividers[i];
+		if (desc->id >= clk_data->num ||
+		    desc->parent_id >= clk_data->num)
+			return -EINVAL;
+
+		parent_hw = clk_data->hws[desc->parent_id];
+		if (!parent_hw)
+			return -EINVAL;
+
+		hw = ultrarisc_clk_register_divider(dev, desc, parent_hw, base,
+						    lock);
+		if (IS_ERR(hw))
+			return PTR_ERR(hw);
+
+		if (desc->max_rate) {
+			unsigned long rate;
+
+			clk_hw_set_rate_range(hw, 0, desc->max_rate);
+
+			rate = clk_hw_get_rate(hw);
+			if (rate > desc->max_rate)
+				dev_warn(dev, "%s rate %lu exceeds max %lu\n",
+					 desc->name, rate, desc->max_rate);
+		}
+
+		clk_data->hws[desc->id] = hw;
+	}
+
+	return 0;
+}
+
+static int ultrarisc_clk_register_gates(struct platform_device *pdev,
+					struct clk_hw_onecell_data *clk_data,
+					const struct ultrarisc_clk_soc_data *soc_data,
+					void __iomem *base,
+					spinlock_t *lock)
+{
+	struct device *dev = &pdev->dev;
+	u32 i;
+
+	for (i = 0; i < soc_data->num_gates; i++) {
+		const struct ultrarisc_gate_desc *desc;
+		struct clk_hw *parent_hw;
+		struct clk_hw *hw;
+
+		desc = &soc_data->gates[i];
+		if (desc->id >= clk_data->num ||
+		    desc->parent_id >= clk_data->num)
+			return -EINVAL;
+
+		parent_hw = clk_data->hws[desc->parent_id];
+		if (!parent_hw)
+			return -EINVAL;
+
+		hw = devm_clk_hw_register_gate_parent_hw(dev, desc->name,
+							 parent_hw,
+							 CLK_GET_RATE_NOCACHE,
+							 base + desc->offset,
+							 desc->gate_bit,
+							 desc->gate_flags,
+							 lock);
+		if (IS_ERR(hw))
+			return PTR_ERR(hw);
+
+		clk_data->hws[desc->id] = hw;
+	}
+
+	return 0;
+}
+
+int ultrarisc_clk_probe(struct platform_device *pdev,
+			const struct ultrarisc_clk_soc_data *soc_data)
+{
+	struct clk_hw_onecell_data *clk_data;
+	struct device *dev = &pdev->dev;
+	void __iomem *base;
+	spinlock_t *lock;
+	int ret;
+
+	if (!soc_data)
+		return -EINVAL;
+
+	lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
+	if (!lock)
+		return -ENOMEM;
+
+	spin_lock_init(lock);
+
+	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws,
+						 soc_data->num_clks),
+				GFP_KERNEL);
+	if (!clk_data)
+		return -ENOMEM;
+
+	clk_data->num = soc_data->num_clks;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	ret = ultrarisc_clk_register_plls(pdev, clk_data, soc_data, base);
+	if (ret)
+		return ret;
+
+	ret = ultrarisc_clk_register_fixed_factors(dev, clk_data, soc_data);
+	if (ret)
+		return ret;
+
+	ret = ultrarisc_clk_register_dividers(pdev, clk_data, soc_data, base,
+					      lock);
+	if (ret)
+		return ret;
+
+	ret = ultrarisc_clk_register_gates(pdev, clk_data, soc_data, base,
+					   lock);
+	if (ret)
+		return ret;
+
+	for (int i = 0; i < clk_data->num; i++) {
+		if (!clk_data->hws[i]) {
+			dev_err(dev, "missing clock ID %u\n", i);
+			return -EINVAL;
+		}
+	}
+
+	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
+					   clk_data);
+}
+EXPORT_SYMBOL_GPL(ultrarisc_clk_probe);
+
+MODULE_DESCRIPTION("UltraRISC clock core driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/clk/ultrarisc/clk-ultrarisc.h b/drivers/clk/ultrarisc/clk-ultrarisc.h
new file mode 100644
index 000000000000..1281196bb414
--- /dev/null
+++ b/drivers/clk/ultrarisc/clk-ultrarisc.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ULTRARISC_CLK_ULTRARISC_H
+#define __ULTRARISC_CLK_ULTRARISC_H
+
+#include <linux/clk-provider.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+#define ULTRARISC_CLK_NO_GATE		(-1)
+
+struct ultrarisc_pll_layout {
+	u32 cfg1_offset;
+	u32 cfg2_offset;
+	u32 frac_mask;
+	u32 m_mask;
+	u32 n_mask;
+	u32 oddiv1_mask;
+	u32 oddiv2_mask;
+};
+
+struct ultrarisc_pll_desc {
+	u32 id;
+	const char *name;
+};
+
+struct ultrarisc_fixed_factor_desc {
+	u32 id;
+	const char *name;
+	u32 parent_id;
+	u32 mult;
+	u32 div;
+};
+
+struct ultrarisc_divider_desc {
+	u32 id;
+	const char *name;
+	u32 offset;
+	u32 parent_id;
+	unsigned long max_rate;
+	u32 load_mask;
+	u8 div_shift;
+	u8 div_width;
+	s8 gate_bit;
+	u16 divider_flags;
+	u8 gate_flags;
+};
+
+struct ultrarisc_gate_desc {
+	u32 id;
+	const char *name;
+	u32 offset;
+	u32 parent_id;
+	u8 gate_bit;
+	u8 gate_flags;
+};
+
+struct ultrarisc_clk_soc_data {
+	const struct ultrarisc_pll_layout *pll_layout;
+	const struct ultrarisc_pll_desc *plls;
+	u32 num_plls;
+	const struct ultrarisc_fixed_factor_desc *fixed_factors;
+	u32 num_fixed_factors;
+	const struct ultrarisc_divider_desc *dividers;
+	u32 num_dividers;
+	const struct ultrarisc_gate_desc *gates;
+	u32 num_gates;
+	u32 num_clks;
+};
+
+int ultrarisc_clk_probe(struct platform_device *pdev,
+			const struct ultrarisc_clk_soc_data *soc_data);
+
+#endif /* __ULTRARISC_CLK_ULTRARISC_H */

-- 
2.34.1

Re: [PATCH v2 2/2] clk: ultrarisc: add DP1000 clock driver

[Jia Wang]

On 2026-06-17 14:02 +0800, Jia Wang wrote:
> Add a clock driver for the UltraRISC DP1000 SoC.
> 
> The clock tree is driven by a SYSPLL and provides fixed-factor clocks for
> the subsystem and PCIe, divider-based root clocks for GMAC and the UART,
> I2C, and SPI blocks, and per-instance gate clocks for UART0-3, I2C0-3,
> and SPI0-1.
> 
> Signed-off-by: Jia Wang <wangjia@ultrarisc.com>
> ---
>  MAINTAINERS                           |   1 +
>  drivers/clk/Kconfig                   |   1 +
>  drivers/clk/Makefile                  |   1 +
>  drivers/clk/ultrarisc/Kconfig         |  18 ++
>  drivers/clk/ultrarisc/Makefile        |   4 +
>  drivers/clk/ultrarisc/clk-dp1000.c    | 153 ++++++++++++
>  drivers/clk/ultrarisc/clk-ultrarisc.c | 459 ++++++++++++++++++++++++++++++++++
>  drivers/clk/ultrarisc/clk-ultrarisc.h |  73 ++++++
>  8 files changed, 710 insertions(+)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index b7e43313c65f..aa5021f30cb5 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -27444,6 +27444,7 @@ M:	Jia Wang <wangjia@ultrarisc.com>
>  L:	linux-clk@vger.kernel.org
>  S:	Maintained
>  F:	Documentation/devicetree/bindings/clock/ultrarisc,dp1000-clk.yaml
> +F:	drivers/clk/ultrarisc/*
>  F:	include/dt-bindings/clock/ultrarisc,dp1000-clk.h
>  
>  ULTRATRONIK BOARD SUPPORT
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index b2efbe9f6acb..75e336858420 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -535,6 +535,7 @@ source "drivers/clk/tenstorrent/Kconfig"
>  source "drivers/clk/thead/Kconfig"
>  source "drivers/clk/stm32/Kconfig"
>  source "drivers/clk/ti/Kconfig"
> +source "drivers/clk/ultrarisc/Kconfig"
>  source "drivers/clk/uniphier/Kconfig"
>  source "drivers/clk/visconti/Kconfig"
>  source "drivers/clk/x86/Kconfig"
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index a3e2862ebd7e..891272e8e1da 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -158,6 +158,7 @@ obj-$(CONFIG_ARCH_TEGRA)		+= tegra/
>  obj-y					+= tenstorrent/
>  obj-$(CONFIG_ARCH_THEAD)		+= thead/
>  obj-y					+= ti/
> +obj-y					+= ultrarisc/
>  obj-$(CONFIG_CLK_UNIPHIER)		+= uniphier/
>  obj-$(CONFIG_ARCH_U8500)		+= ux500/
>  obj-y					+= versatile/
> diff --git a/drivers/clk/ultrarisc/Kconfig b/drivers/clk/ultrarisc/Kconfig
> new file mode 100644
> index 000000000000..2eecc6ac3119
> --- /dev/null
> +++ b/drivers/clk/ultrarisc/Kconfig
> @@ -0,0 +1,18 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +config CLK_ULTRARISC
> +	tristate
> +	depends on OF
> +	depends on ARCH_ULTRARISC || COMPILE_TEST
> +
> +config CLK_ULTRARISC_DP1000
> +	tristate "UltraRISC DP1000 clock controller"
> +	select CLK_ULTRARISC
> +	depends on OF && HAS_IOMEM
> +	depends on ARCH_ULTRARISC || COMPILE_TEST
> +	default ARCH_ULTRARISC
> +	help
> +	  This driver provides the clock controller for the UltraRISC
> +	  DP1000 SoC. It exposes the PLL output, derived fixed-factor
> +	  clocks, programmable divider clocks, and peripheral gate
> +	  clocks to Linux consumers.
> diff --git a/drivers/clk/ultrarisc/Makefile b/drivers/clk/ultrarisc/Makefile
> new file mode 100644
> index 000000000000..b013708c9444
> --- /dev/null
> +++ b/drivers/clk/ultrarisc/Makefile
> @@ -0,0 +1,4 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +obj-$(CONFIG_CLK_ULTRARISC) += clk-ultrarisc.o
> +obj-$(CONFIG_CLK_ULTRARISC_DP1000) += clk-dp1000.o
> diff --git a/drivers/clk/ultrarisc/clk-dp1000.c b/drivers/clk/ultrarisc/clk-dp1000.c
> new file mode 100644
> index 000000000000..33a16df8f189
> --- /dev/null
> +++ b/drivers/clk/ultrarisc/clk-dp1000.c
> @@ -0,0 +1,153 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2026 UltraRISC Technology (Shanghai) Co., Ltd.
> + */
> +
> +#include <linux/module.h>
> +
> +#include <dt-bindings/clock/ultrarisc,dp1000-clk.h>
> +
> +#include "clk-ultrarisc.h"
> +
> +#define DP1000_PLL_CFG1_OFFSET		0x400
> +#define DP1000_PLL_CFG2_OFFSET		0x404
> +
> +#define DP1000_CCR_UART_OFFSET		0x220
> +#define DP1000_CCR_I2C_OFFSET		0x224
> +#define DP1000_CCR_GMAC_OFFSET		0x228
> +#define DP1000_CCR_SPI_OFFSET		0x22c
> +#define DP1000_PERI_CLKENA_OFFSET	0x270
> +
> +#define DP1000_CCR_LOAD			BIT(16)
> +
> +#define DP1000_PERI_MAX_RATE		62500000UL
> +#define DP1000_CLK_NUM			21
> +
> +static const struct ultrarisc_pll_layout dp1000_pll_layout = {
> +	.cfg1_offset = DP1000_PLL_CFG1_OFFSET,
> +	.cfg2_offset = DP1000_PLL_CFG2_OFFSET,
> +	.frac_mask = GENMASK(23, 0),
> +	.m_mask = GENMASK(23, 16),
> +	.n_mask = GENMASK(11, 6),
> +	.oddiv1_mask = GENMASK(4, 3),
> +	.oddiv2_mask = GENMASK(1, 0),
> +};
> +
> +static const struct ultrarisc_pll_desc dp1000_plls[] = {
> +	{
> +		.id = DP1000_CLK_SYSPLL,
> +		.name = "syspll_clk",
> +	},
> +};
> +
> +#define DP1000_FIXED_FACTOR(_id, _name, _parent, _mult, _div)	\
> +	{							\
> +		.id = (_id),					\
> +		.name = (_name),				\
> +		.parent_id = (_parent),				\
> +		.mult = (_mult),				\
> +		.div = (_div),					\
> +	}
> +
> +#define DP1000_DIV(_id, _name, _offset, _parent, _max_rate)	\
> +	{							\
> +		.id = (_id),					\
> +		.name = (_name),				\
> +		.offset = (_offset),				\
> +		.parent_id = (_parent),				\
> +		.max_rate = (_max_rate),			\
> +		.load_mask = DP1000_CCR_LOAD,			\
> +		.div_shift = 8,					\
> +		.div_width = 4,					\
> +		.gate_bit = 0,					\
> +		.divider_flags = CLK_DIVIDER_ONE_BASED,		\
> +		.gate_flags = 0,				\
> +	}
> +
> +#define DP1000_GATE(_id, _name, _parent, _bit)		\
> +	{							\
> +		.id = (_id),					\
> +		.name = (_name),				\
> +		.offset = DP1000_PERI_CLKENA_OFFSET,		\
> +		.parent_id = (_parent),				\
> +		.gate_bit = (_bit),				\
> +		.gate_flags = 0,				\
> +	}
> +
> +static const struct ultrarisc_fixed_factor_desc dp1000_fixed_factor_clks[] = {
> +	DP1000_FIXED_FACTOR(DP1000_CLK_SYSPLL_DIV2, "syspll_div2_clk",
> +			    DP1000_CLK_SYSPLL, 1, 2),
> +	DP1000_FIXED_FACTOR(DP1000_CLK_SUBSYS, "subsys_clk",
> +			    DP1000_CLK_SYSPLL_DIV2, 1, 2),
> +	DP1000_FIXED_FACTOR(DP1000_CLK_PCIE_DBI, "pcie_dbi_clk",
> +			    DP1000_CLK_SYSPLL, 1, 10),
> +	DP1000_FIXED_FACTOR(DP1000_CLK_PCIEX4_CORE, "pciex4_core_clk",
> +			    DP1000_CLK_SYSPLL, 1, 2),
> +	DP1000_FIXED_FACTOR(DP1000_CLK_PCIEX16_CORE, "pciex16_core_clk",
> +			    DP1000_CLK_SYSPLL, 1, 1),
> +	DP1000_FIXED_FACTOR(DP1000_CLK_PCIE_AUX, "pcie_aux_clk",
> +			    DP1000_CLK_SYSPLL, 1, 40),
> +};
> +
> +static const struct ultrarisc_divider_desc dp1000_divider_clks[] = {
> +	DP1000_DIV(DP1000_CLK_GMAC, "gmac_clk", DP1000_CCR_GMAC_OFFSET,
> +		   DP1000_CLK_SYSPLL_DIV2, 0),
> +	DP1000_DIV(DP1000_CLK_UART_ROOT, "uart_root_clk",
> +		   DP1000_CCR_UART_OFFSET, DP1000_CLK_SUBSYS,
> +		   DP1000_PERI_MAX_RATE),
> +	DP1000_DIV(DP1000_CLK_I2C_ROOT, "i2c_root_clk",
> +		   DP1000_CCR_I2C_OFFSET, DP1000_CLK_SUBSYS,
> +		   DP1000_PERI_MAX_RATE),
> +	DP1000_DIV(DP1000_CLK_SPI_ROOT, "spi_root_clk",
> +		   DP1000_CCR_SPI_OFFSET, DP1000_CLK_SUBSYS,
> +		   DP1000_PERI_MAX_RATE),
> +};
> +
> +static const struct ultrarisc_gate_desc dp1000_gate_clks[] = {
> +	DP1000_GATE(DP1000_CLK_UART0, "uart0_clk", DP1000_CLK_UART_ROOT, 0),
> +	DP1000_GATE(DP1000_CLK_UART1, "uart1_clk", DP1000_CLK_UART_ROOT, 1),
> +	DP1000_GATE(DP1000_CLK_UART2, "uart2_clk", DP1000_CLK_UART_ROOT, 2),
> +	DP1000_GATE(DP1000_CLK_UART3, "uart3_clk", DP1000_CLK_UART_ROOT, 3),
> +	DP1000_GATE(DP1000_CLK_I2C0, "i2c0_clk", DP1000_CLK_I2C_ROOT, 4),
> +	DP1000_GATE(DP1000_CLK_I2C1, "i2c1_clk", DP1000_CLK_I2C_ROOT, 5),
> +	DP1000_GATE(DP1000_CLK_I2C2, "i2c2_clk", DP1000_CLK_I2C_ROOT, 6),
> +	DP1000_GATE(DP1000_CLK_I2C3, "i2c3_clk", DP1000_CLK_I2C_ROOT, 7),
> +	DP1000_GATE(DP1000_CLK_SPI0, "spi0_clk", DP1000_CLK_SPI_ROOT, 8),
> +	DP1000_GATE(DP1000_CLK_SPI1, "spi1_clk", DP1000_CLK_SPI_ROOT, 9),
> +};
> +
> +static const struct ultrarisc_clk_soc_data dp1000_clk_soc_data = {
> +	.num_clks = DP1000_CLK_NUM,
> +	.pll_layout = &dp1000_pll_layout,
> +	.plls = dp1000_plls,
> +	.num_plls = ARRAY_SIZE(dp1000_plls),
> +	.fixed_factors = dp1000_fixed_factor_clks,
> +	.num_fixed_factors = ARRAY_SIZE(dp1000_fixed_factor_clks),
> +	.dividers = dp1000_divider_clks,
> +	.num_dividers = ARRAY_SIZE(dp1000_divider_clks),
> +	.gates = dp1000_gate_clks,
> +	.num_gates = ARRAY_SIZE(dp1000_gate_clks),
> +};
> +
> +static int dp1000_clk_probe(struct platform_device *pdev)
> +{
> +	return ultrarisc_clk_probe(pdev, &dp1000_clk_soc_data);
> +}
> +
> +static const struct of_device_id dp1000_clk_of_match[] = {
> +	{ .compatible = "ultrarisc,dp1000-clk" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, dp1000_clk_of_match);
> +
> +static struct platform_driver dp1000_clk_driver = {
> +	.probe = dp1000_clk_probe,
> +	.driver = {
> +		.name = "ultrarisc-dp1000-clk",
> +		.of_match_table = dp1000_clk_of_match,
> +	},
> +};
> +module_platform_driver(dp1000_clk_driver);
> +
> +MODULE_DESCRIPTION("UltraRISC DP1000 clock controller");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/clk/ultrarisc/clk-ultrarisc.c b/drivers/clk/ultrarisc/clk-ultrarisc.c
> new file mode 100644
> index 000000000000..4ef222348dd7
> --- /dev/null
> +++ b/drivers/clk/ultrarisc/clk-ultrarisc.c
> @@ -0,0 +1,459 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2026 UltraRISC Technology (Shanghai) Co., Ltd.
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/clk-provider.h>
> +#include <linux/io.h>
> +#include <linux/math64.h>
> +#include <linux/module.h>
> +#include <linux/of_clk.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +
> +#include "clk-ultrarisc.h"
> +
> +struct ultrarisc_pll_clk {
> +	struct clk_hw hw;
> +	void __iomem *base;
> +	const struct ultrarisc_pll_layout *layout;
> +};
> +
> +struct ultrarisc_divider_clk {
> +	struct clk_divider divider;
> +	struct clk_gate gate;
> +	u32 load_mask;
> +};
> +
> +#define to_ultrarisc_pll_clk(_hw) \
> +	container_of(_hw, struct ultrarisc_pll_clk, hw)
> +
> +static inline struct ultrarisc_divider_clk *
> +to_ultrarisc_divider_clk(struct clk_hw *hw)
> +{
> +	struct clk_divider *divider = to_clk_divider(hw);
> +
> +	return container_of(divider, struct ultrarisc_divider_clk, divider);
> +}
> +
> +static unsigned long ultrarisc_pll_recalc_rate(struct clk_hw *hw,
> +					       unsigned long parent_rate)
> +{
> +	struct ultrarisc_pll_clk *pll = to_ultrarisc_pll_clk(hw);
> +	const struct ultrarisc_pll_layout *layout = pll->layout;
> +	u32 oddiv1_div, oddiv2_div;
> +	u64 mult, rate, den;
> +	u32 frac, m, n;
> +	u32 cfg1, cfg2;
> +
> +	cfg1 = readl_relaxed(pll->base + layout->cfg1_offset);
> +	cfg2 = readl_relaxed(pll->base + layout->cfg2_offset);
> +
> +	frac = field_get(layout->frac_mask, cfg1);
> +	m = field_get(layout->m_mask, cfg2);
> +	n = field_get(layout->n_mask, cfg2);
> +	oddiv1_div = 1U << field_get(layout->oddiv1_mask, cfg2);
> +	oddiv2_div = 1U << field_get(layout->oddiv2_mask, cfg2);
> +
> +	if (!n)
> +		return 0;
> +
> +	/*
> +	 * The output frequency is calculated as:
> +	 * fvco = parent * (m + frac / 2^24) / n
> +	 * fout = fvco / (2^oddiv1_raw * 2^oddiv2_raw)
> +	 *
> +	 * The output divider values are derived from the raw register field
> +	 * values as:
> +	 * oddivX_div = 1 << oddivX_raw
> +	 */
> +	mult = ((u64)m << 24) + frac;
> +	rate = (u64)parent_rate * mult;
> +	den = ((u64)n << 24) * oddiv1_div * oddiv2_div;
> +
> +	return div64_u64(rate + (den >> 1), den);
> +}
> +
> +static const struct clk_ops ultrarisc_pll_ro_ops = {
> +	.recalc_rate = ultrarisc_pll_recalc_rate,
> +};
> +
> +static unsigned long
> +ultrarisc_divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
> +{
> +	struct clk_divider *divider = to_clk_divider(hw);
> +	u32 val;
> +
> +	val = readl_relaxed(divider->reg) >> divider->shift;
> +	val &= clk_div_mask(divider->width);
> +
> +	return divider_recalc_rate(hw, parent_rate, val, divider->table,
> +				   divider->flags, divider->width);
> +}
> +
> +static int ultrarisc_divider_determine_rate(struct clk_hw *hw,
> +					    struct clk_rate_request *req)
> +{
> +	struct clk_divider *divider = to_clk_divider(hw);
> +
> +	return divider_determine_rate(hw, req, divider->table, divider->width,
> +				      divider->flags);
> +}
> +
> +static int ultrarisc_divider_set_rate(struct clk_hw *hw, unsigned long rate,
> +				      unsigned long parent_rate)
> +{
> +	struct ultrarisc_divider_clk *divider_clk = to_ultrarisc_divider_clk(hw);
> +	struct clk_divider *divider = &divider_clk->divider;
> +	int value;
> +	u32 val;
> +
> +	value = divider_get_val(rate, parent_rate, divider->table,
> +				divider->width, divider->flags);
> +	if (value < 0)
> +		return value;
> +
> +	scoped_guard(spinlock_irqsave, divider->lock) {
> +		val = readl_relaxed(divider->reg);
> +		val &= ~(clk_div_mask(divider->width) << divider->shift);
> +		val |= value << divider->shift;
> +		writel_relaxed(val, divider->reg);
> +
> +		if (divider_clk->load_mask) {
> +			/*
> +			 * Program the new divider field, then write 1 to the
> +			 * load bit to trigger the update. The load bit is
> +			 * write-triggered and reads back as 0 on this hardware.
> +			 */
> +			writel_relaxed(val | divider_clk->load_mask,
> +				       divider->reg);
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct clk_ops ultrarisc_divider_ops = {
> +	.recalc_rate = ultrarisc_divider_recalc_rate,
> +	.determine_rate = ultrarisc_divider_determine_rate,
> +	.set_rate = ultrarisc_divider_set_rate,
> +};
> +
> +static void ultrarisc_clk_unregister_composite(void *data)
> +{
> +	clk_hw_unregister_composite(data);
> +}
> +
> +static struct clk_hw *
> +ultrarisc_clk_hw_register_composite(struct device *dev, const char *name,
> +				    const char * const *parent_names,
> +				    int num_parents, struct clk_hw *mux_hw,
> +				    const struct clk_ops *mux_ops,
> +				    struct clk_hw *rate_hw,
> +				    const struct clk_ops *rate_ops,
> +				    struct clk_hw *gate_hw,
> +				    const struct clk_ops *gate_ops,
> +				    unsigned long flags)
> +{
> +	struct clk_hw *hw;
> +	int ret;
> +
> +	hw = clk_hw_register_composite(dev, name, parent_names, num_parents,
> +				       mux_hw, mux_ops, rate_hw, rate_ops,
> +				       gate_hw, gate_ops, flags);
> +	if (IS_ERR(hw))
> +		return hw;
> +
> +	ret = devm_add_action_or_reset(dev, ultrarisc_clk_unregister_composite,
> +				       hw);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	return hw;
> +}
> +
> +static struct clk_hw *ultrarisc_clk_register_pll(struct device *dev,
> +						 const struct ultrarisc_pll_desc *desc,
> +						 const struct ultrarisc_pll_layout *layout,
> +						 void __iomem *base)
> +{
> +	struct clk_parent_data pdata = { .index = 0 };
> +	struct ultrarisc_pll_clk *pll;
> +	struct clk_init_data init = {
> +		.name = desc->name,
> +		.ops = &ultrarisc_pll_ro_ops,
> +		.parent_data = &pdata,
> +		.num_parents = 1,
> +		.flags = CLK_GET_RATE_NOCACHE,
> +	};
> +	int ret;
> +
> +	pll = devm_kzalloc(dev, sizeof(*pll), GFP_KERNEL);
> +	if (!pll)
> +		return ERR_PTR(-ENOMEM);
> +
> +	pll->base = base;
> +	pll->layout = layout;
> +	pll->hw.init = &init;
> +
> +	ret = devm_clk_hw_register(dev, &pll->hw);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	return &pll->hw;
> +}
> +
> +static struct clk_hw *
> +ultrarisc_clk_register_divider(struct device *dev,
> +			       const struct ultrarisc_divider_desc *desc,
> +			       struct clk_hw *parent_hw, void __iomem *base,
> +			       spinlock_t *lock)
> +{
> +	const char * const parent_names[] = { clk_hw_get_name(parent_hw) };
> +	void __iomem *reg = base + desc->offset;
> +	struct ultrarisc_divider_clk *divider;
> +	const struct clk_ops *gate_ops = NULL;
> +	struct clk_hw *gate_hw = NULL;
> +
> +	if (!desc->div_width)
> +		return ERR_PTR(-EINVAL);
> +
> +	if (!lock)
> +		return ERR_PTR(-EINVAL);
> +
> +	divider = devm_kzalloc(dev, sizeof(*divider), GFP_KERNEL);
> +	if (!divider)
> +		return ERR_PTR(-ENOMEM);
> +
> +	divider->divider.reg = reg;
> +	divider->divider.shift = desc->div_shift;
> +	divider->divider.width = desc->div_width;
> +	divider->divider.flags = desc->divider_flags;
> +	divider->divider.lock = lock;
> +	divider->load_mask = desc->load_mask;
> +
> +	if (desc->gate_bit != ULTRARISC_CLK_NO_GATE) {
> +		divider->gate.reg = reg;
> +		divider->gate.bit_idx = desc->gate_bit;
> +		divider->gate.flags = desc->gate_flags;
> +		divider->gate.lock = lock;
> +		gate_hw = &divider->gate.hw;
> +		gate_ops = &clk_gate_ops;
> +	}
> +
> +	return ultrarisc_clk_hw_register_composite(dev, desc->name,
> +						   parent_names, 1,
> +						   NULL, NULL,
> +						   &divider->divider.hw,
> +						   &ultrarisc_divider_ops,
> +						   gate_hw, gate_ops,
> +						   CLK_GET_RATE_NOCACHE);
> +}
> +
> +static int ultrarisc_clk_register_fixed_factors(struct device *dev,
> +						struct clk_hw_onecell_data *clk_data,
> +						const struct ultrarisc_clk_soc_data *soc_data)
> +{
> +	u32 i;
> +
> +	for (i = 0; i < soc_data->num_fixed_factors; i++) {
> +		const struct ultrarisc_fixed_factor_desc *desc;
> +		struct clk_hw *parent_hw;
> +		struct clk_hw *hw;
> +
> +		desc = &soc_data->fixed_factors[i];
> +		if (desc->id >= clk_data->num ||
> +		    desc->parent_id >= clk_data->num)
> +			return -EINVAL;
> +
> +		parent_hw = clk_data->hws[desc->parent_id];
> +		if (!parent_hw)
> +			return -EINVAL;
> +
> +		hw = devm_clk_hw_register_fixed_factor_parent_hw(dev, desc->name,
> +								 parent_hw,
> +								 CLK_GET_RATE_NOCACHE,
> +								 desc->mult,
> +								 desc->div);
> +		if (IS_ERR(hw))
> +			return PTR_ERR(hw);
> +
> +		clk_data->hws[desc->id] = hw;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ultrarisc_clk_register_plls(struct platform_device *pdev,
> +				       struct clk_hw_onecell_data *clk_data,
> +				       const struct ultrarisc_clk_soc_data *soc_data,
> +				       void __iomem *base)
> +{
> +	struct device *dev = &pdev->dev;
> +	u32 i;
> +
> +	for (i = 0; i < soc_data->num_plls; i++) {
> +		const struct ultrarisc_pll_desc *desc = &soc_data->plls[i];
> +		struct clk_hw *hw;
> +
> +		if (desc->id >= clk_data->num)
> +			return -EINVAL;
> +
> +		hw = ultrarisc_clk_register_pll(dev, desc, soc_data->pll_layout,
> +						base);
> +		if (IS_ERR(hw))
> +			return PTR_ERR(hw);
> +
> +		clk_data->hws[desc->id] = hw;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ultrarisc_clk_register_dividers(struct platform_device *pdev,
> +					   struct clk_hw_onecell_data *clk_data,
> +					   const struct ultrarisc_clk_soc_data *soc_data,
> +					   void __iomem *base,
> +					   spinlock_t *lock)
> +{
> +	struct device *dev = &pdev->dev;
> +	u32 i;
> +
> +	for (i = 0; i < soc_data->num_dividers; i++) {
> +		const struct ultrarisc_divider_desc *desc;
> +		struct clk_hw *parent_hw;
> +		struct clk_hw *hw;
> +
> +		desc = &soc_data->dividers[i];
> +		if (desc->id >= clk_data->num ||
> +		    desc->parent_id >= clk_data->num)
> +			return -EINVAL;
> +
> +		parent_hw = clk_data->hws[desc->parent_id];
> +		if (!parent_hw)
> +			return -EINVAL;
> +
> +		hw = ultrarisc_clk_register_divider(dev, desc, parent_hw, base,
> +						    lock);
> +		if (IS_ERR(hw))
> +			return PTR_ERR(hw);
> +
> +		if (desc->max_rate) {
> +			unsigned long rate;
> +
> +			clk_hw_set_rate_range(hw, 0, desc->max_rate);
> +
> +			rate = clk_hw_get_rate(hw);
> +			if (rate > desc->max_rate)
> +				dev_warn(dev, "%s rate %lu exceeds max %lu\n",
> +					 desc->name, rate, desc->max_rate);
> +		}
> +
> +		clk_data->hws[desc->id] = hw;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ultrarisc_clk_register_gates(struct platform_device *pdev,
> +					struct clk_hw_onecell_data *clk_data,
> +					const struct ultrarisc_clk_soc_data *soc_data,
> +					void __iomem *base,
> +					spinlock_t *lock)
> +{
> +	struct device *dev = &pdev->dev;
> +	u32 i;
> +
> +	for (i = 0; i < soc_data->num_gates; i++) {
> +		const struct ultrarisc_gate_desc *desc;
> +		struct clk_hw *parent_hw;
> +		struct clk_hw *hw;
> +
> +		desc = &soc_data->gates[i];
> +		if (desc->id >= clk_data->num ||
> +		    desc->parent_id >= clk_data->num)
> +			return -EINVAL;
> +
> +		parent_hw = clk_data->hws[desc->parent_id];
> +		if (!parent_hw)
> +			return -EINVAL;
> +
> +		hw = devm_clk_hw_register_gate_parent_hw(dev, desc->name,
> +							 parent_hw,
> +							 CLK_GET_RATE_NOCACHE,
> +							 base + desc->offset,
> +							 desc->gate_bit,
> +							 desc->gate_flags,
> +							 lock);
> +		if (IS_ERR(hw))
> +			return PTR_ERR(hw);
> +
> +		clk_data->hws[desc->id] = hw;
> +	}
> +
> +	return 0;
> +}
> +
> +int ultrarisc_clk_probe(struct platform_device *pdev,
> +			const struct ultrarisc_clk_soc_data *soc_data)
> +{
> +	struct clk_hw_onecell_data *clk_data;
> +	struct device *dev = &pdev->dev;
> +	void __iomem *base;
> +	spinlock_t *lock;
> +	int ret;
> +
> +	if (!soc_data)
> +		return -EINVAL;
> +
> +	lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
> +	if (!lock)
> +		return -ENOMEM;
> +
> +	spin_lock_init(lock);
> +
> +	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws,
> +						 soc_data->num_clks),
> +				GFP_KERNEL);
> +	if (!clk_data)
> +		return -ENOMEM;
> +
> +	clk_data->num = soc_data->num_clks;
> +
> +	base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(base))
> +		return PTR_ERR(base);
> +
> +	ret = ultrarisc_clk_register_plls(pdev, clk_data, soc_data, base);
> +	if (ret)
> +		return ret;
> +
> +	ret = ultrarisc_clk_register_fixed_factors(dev, clk_data, soc_data);
> +	if (ret)
> +		return ret;
> +
> +	ret = ultrarisc_clk_register_dividers(pdev, clk_data, soc_data, base,
> +					      lock);
> +	if (ret)
> +		return ret;
> +
> +	ret = ultrarisc_clk_register_gates(pdev, clk_data, soc_data, base,
> +					   lock);
> +	if (ret)
> +		return ret;
> +
> +	for (int i = 0; i < clk_data->num; i++) {
> +		if (!clk_data->hws[i]) {
> +			dev_err(dev, "missing clock ID %u\n", i);
> +			return -EINVAL;
> +		}
> +	}
> +
> +	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
> +					   clk_data);
> +}
> +EXPORT_SYMBOL_GPL(ultrarisc_clk_probe);
> +
> +MODULE_DESCRIPTION("UltraRISC clock core driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/clk/ultrarisc/clk-ultrarisc.h b/drivers/clk/ultrarisc/clk-ultrarisc.h
> new file mode 100644
> index 000000000000..1281196bb414
> --- /dev/null
> +++ b/drivers/clk/ultrarisc/clk-ultrarisc.h
> @@ -0,0 +1,73 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef __ULTRARISC_CLK_ULTRARISC_H
> +#define __ULTRARISC_CLK_ULTRARISC_H
> +
> +#include <linux/clk-provider.h>
> +#include <linux/platform_device.h>
> +#include <linux/types.h>
> +
> +#define ULTRARISC_CLK_NO_GATE		(-1)
> +
> +struct ultrarisc_pll_layout {
> +	u32 cfg1_offset;
> +	u32 cfg2_offset;
> +	u32 frac_mask;
> +	u32 m_mask;
> +	u32 n_mask;
> +	u32 oddiv1_mask;
> +	u32 oddiv2_mask;
> +};
> +
> +struct ultrarisc_pll_desc {
> +	u32 id;
> +	const char *name;
> +};
> +
> +struct ultrarisc_fixed_factor_desc {
> +	u32 id;
> +	const char *name;
> +	u32 parent_id;
> +	u32 mult;
> +	u32 div;
> +};
> +
> +struct ultrarisc_divider_desc {
> +	u32 id;
> +	const char *name;
> +	u32 offset;
> +	u32 parent_id;
> +	unsigned long max_rate;
> +	u32 load_mask;
> +	u8 div_shift;
> +	u8 div_width;
> +	s8 gate_bit;
> +	u16 divider_flags;
> +	u8 gate_flags;
> +};
> +
> +struct ultrarisc_gate_desc {
> +	u32 id;
> +	const char *name;
> +	u32 offset;
> +	u32 parent_id;
> +	u8 gate_bit;
> +	u8 gate_flags;
> +};
> +
> +struct ultrarisc_clk_soc_data {
> +	const struct ultrarisc_pll_layout *pll_layout;
> +	const struct ultrarisc_pll_desc *plls;
> +	u32 num_plls;
> +	const struct ultrarisc_fixed_factor_desc *fixed_factors;
> +	u32 num_fixed_factors;
> +	const struct ultrarisc_divider_desc *dividers;
> +	u32 num_dividers;
> +	const struct ultrarisc_gate_desc *gates;
> +	u32 num_gates;
> +	u32 num_clks;
> +};
> +
> +int ultrarisc_clk_probe(struct platform_device *pdev,
> +			const struct ultrarisc_clk_soc_data *soc_data);
> +
> +#endif /* __ULTRARISC_CLK_ULTRARISC_H */
> 
> -- 
> 2.34.1
> 
>

Gentle ping.

Best Regards,
Jia Wang 

Re: [PATCH v2 2/2] clk: ultrarisc: add DP1000 clock driver

[Brian Masney]

Hi Jia,

Thanks for the patch.

On Wed, Jun 17, 2026 at 02:02:55PM +0800, Jia Wang wrote:
> Add a clock driver for the UltraRISC DP1000 SoC.
> 
> The clock tree is driven by a SYSPLL and provides fixed-factor clocks for
> the subsystem and PCIe, divider-based root clocks for GMAC and the UART,
> I2C, and SPI blocks, and per-instance gate clocks for UART0-3, I2C0-3,
> and SPI0-1.
> 
> Signed-off-by: Jia Wang <wangjia@ultrarisc.com>
> ---
>  MAINTAINERS                           |   1 +
>  drivers/clk/Kconfig                   |   1 +
>  drivers/clk/Makefile                  |   1 +
>  drivers/clk/ultrarisc/Kconfig         |  18 ++
>  drivers/clk/ultrarisc/Makefile        |   4 +
>  drivers/clk/ultrarisc/clk-dp1000.c    | 153 ++++++++++++
>  drivers/clk/ultrarisc/clk-ultrarisc.c | 459 ++++++++++++++++++++++++++++++++++
>  drivers/clk/ultrarisc/clk-ultrarisc.h |  73 ++++++
>  8 files changed, 710 insertions(+)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index b7e43313c65f..aa5021f30cb5 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -27444,6 +27444,7 @@ M:	Jia Wang <wangjia@ultrarisc.com>
>  L:	linux-clk@vger.kernel.org
>  S:	Maintained
>  F:	Documentation/devicetree/bindings/clock/ultrarisc,dp1000-clk.yaml
> +F:	drivers/clk/ultrarisc/*
>  F:	include/dt-bindings/clock/ultrarisc,dp1000-clk.h
>  
>  ULTRATRONIK BOARD SUPPORT
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index b2efbe9f6acb..75e336858420 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -535,6 +535,7 @@ source "drivers/clk/tenstorrent/Kconfig"
>  source "drivers/clk/thead/Kconfig"
>  source "drivers/clk/stm32/Kconfig"
>  source "drivers/clk/ti/Kconfig"
> +source "drivers/clk/ultrarisc/Kconfig"
>  source "drivers/clk/uniphier/Kconfig"
>  source "drivers/clk/visconti/Kconfig"
>  source "drivers/clk/x86/Kconfig"
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index a3e2862ebd7e..891272e8e1da 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -158,6 +158,7 @@ obj-$(CONFIG_ARCH_TEGRA)		+= tegra/
>  obj-y					+= tenstorrent/
>  obj-$(CONFIG_ARCH_THEAD)		+= thead/
>  obj-y					+= ti/
> +obj-y					+= ultrarisc/
>  obj-$(CONFIG_CLK_UNIPHIER)		+= uniphier/
>  obj-$(CONFIG_ARCH_U8500)		+= ux500/
>  obj-y					+= versatile/
> diff --git a/drivers/clk/ultrarisc/Kconfig b/drivers/clk/ultrarisc/Kconfig
> new file mode 100644
> index 000000000000..2eecc6ac3119
> --- /dev/null
> +++ b/drivers/clk/ultrarisc/Kconfig
> @@ -0,0 +1,18 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +config CLK_ULTRARISC
> +	tristate
> +	depends on OF
> +	depends on ARCH_ULTRARISC || COMPILE_TEST
> +
> +config CLK_ULTRARISC_DP1000
> +	tristate "UltraRISC DP1000 clock controller"
> +	select CLK_ULTRARISC
> +	depends on OF && HAS_IOMEM
> +	depends on ARCH_ULTRARISC || COMPILE_TEST
> +	default ARCH_ULTRARISC
> +	help
> +	  This driver provides the clock controller for the UltraRISC
> +	  DP1000 SoC. It exposes the PLL output, derived fixed-factor
> +	  clocks, programmable divider clocks, and peripheral gate
> +	  clocks to Linux consumers.
> diff --git a/drivers/clk/ultrarisc/Makefile b/drivers/clk/ultrarisc/Makefile
> new file mode 100644
> index 000000000000..b013708c9444
> --- /dev/null
> +++ b/drivers/clk/ultrarisc/Makefile
> @@ -0,0 +1,4 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +obj-$(CONFIG_CLK_ULTRARISC) += clk-ultrarisc.o
> +obj-$(CONFIG_CLK_ULTRARISC_DP1000) += clk-dp1000.o
> diff --git a/drivers/clk/ultrarisc/clk-dp1000.c b/drivers/clk/ultrarisc/clk-dp1000.c
> new file mode 100644
> index 000000000000..33a16df8f189
> --- /dev/null
> +++ b/drivers/clk/ultrarisc/clk-dp1000.c
> @@ -0,0 +1,153 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2026 UltraRISC Technology (Shanghai) Co., Ltd.
> + */
> +
> +#include <linux/module.h>
> +
> +#include <dt-bindings/clock/ultrarisc,dp1000-clk.h>
> +
> +#include "clk-ultrarisc.h"
> +
> +#define DP1000_PLL_CFG1_OFFSET		0x400
> +#define DP1000_PLL_CFG2_OFFSET		0x404
> +
> +#define DP1000_CCR_UART_OFFSET		0x220
> +#define DP1000_CCR_I2C_OFFSET		0x224
> +#define DP1000_CCR_GMAC_OFFSET		0x228
> +#define DP1000_CCR_SPI_OFFSET		0x22c
> +#define DP1000_PERI_CLKENA_OFFSET	0x270
> +
> +#define DP1000_CCR_LOAD			BIT(16)
> +
> +#define DP1000_PERI_MAX_RATE		62500000UL
> +#define DP1000_CLK_NUM			21
> +
> +static const struct ultrarisc_pll_layout dp1000_pll_layout = {
> +	.cfg1_offset = DP1000_PLL_CFG1_OFFSET,
> +	.cfg2_offset = DP1000_PLL_CFG2_OFFSET,
> +	.frac_mask = GENMASK(23, 0),
> +	.m_mask = GENMASK(23, 16),
> +	.n_mask = GENMASK(11, 6),
> +	.oddiv1_mask = GENMASK(4, 3),
> +	.oddiv2_mask = GENMASK(1, 0),
> +};
> +
> +static const struct ultrarisc_pll_desc dp1000_plls[] = {
> +	{
> +		.id = DP1000_CLK_SYSPLL,
> +		.name = "syspll_clk",
> +	},
> +};
> +
> +#define DP1000_FIXED_FACTOR(_id, _name, _parent, _mult, _div)	\
> +	{							\
> +		.id = (_id),					\
> +		.name = (_name),				\
> +		.parent_id = (_parent),				\
> +		.mult = (_mult),				\
> +		.div = (_div),					\
> +	}
> +
> +#define DP1000_DIV(_id, _name, _offset, _parent, _max_rate)	\
> +	{							\
> +		.id = (_id),					\
> +		.name = (_name),				\
> +		.offset = (_offset),				\
> +		.parent_id = (_parent),				\
> +		.max_rate = (_max_rate),			\
> +		.load_mask = DP1000_CCR_LOAD,			\
> +		.div_shift = 8,					\
> +		.div_width = 4,					\
> +		.gate_bit = 0,					\
> +		.divider_flags = CLK_DIVIDER_ONE_BASED,		\
> +		.gate_flags = 0,				\
> +	}
> +
> +#define DP1000_GATE(_id, _name, _parent, _bit)		\
> +	{							\
> +		.id = (_id),					\
> +		.name = (_name),				\
> +		.offset = DP1000_PERI_CLKENA_OFFSET,		\
> +		.parent_id = (_parent),				\
> +		.gate_bit = (_bit),				\
> +		.gate_flags = 0,				\
> +	}
> +
> +static const struct ultrarisc_fixed_factor_desc dp1000_fixed_factor_clks[] = {
> +	DP1000_FIXED_FACTOR(DP1000_CLK_SYSPLL_DIV2, "syspll_div2_clk",
> +			    DP1000_CLK_SYSPLL, 1, 2),
> +	DP1000_FIXED_FACTOR(DP1000_CLK_SUBSYS, "subsys_clk",
> +			    DP1000_CLK_SYSPLL_DIV2, 1, 2),
> +	DP1000_FIXED_FACTOR(DP1000_CLK_PCIE_DBI, "pcie_dbi_clk",
> +			    DP1000_CLK_SYSPLL, 1, 10),
> +	DP1000_FIXED_FACTOR(DP1000_CLK_PCIEX4_CORE, "pciex4_core_clk",
> +			    DP1000_CLK_SYSPLL, 1, 2),
> +	DP1000_FIXED_FACTOR(DP1000_CLK_PCIEX16_CORE, "pciex16_core_clk",
> +			    DP1000_CLK_SYSPLL, 1, 1),
> +	DP1000_FIXED_FACTOR(DP1000_CLK_PCIE_AUX, "pcie_aux_clk",
> +			    DP1000_CLK_SYSPLL, 1, 40),
> +};
> +
> +static const struct ultrarisc_divider_desc dp1000_divider_clks[] = {
> +	DP1000_DIV(DP1000_CLK_GMAC, "gmac_clk", DP1000_CCR_GMAC_OFFSET,
> +		   DP1000_CLK_SYSPLL_DIV2, 0),
> +	DP1000_DIV(DP1000_CLK_UART_ROOT, "uart_root_clk",
> +		   DP1000_CCR_UART_OFFSET, DP1000_CLK_SUBSYS,
> +		   DP1000_PERI_MAX_RATE),
> +	DP1000_DIV(DP1000_CLK_I2C_ROOT, "i2c_root_clk",
> +		   DP1000_CCR_I2C_OFFSET, DP1000_CLK_SUBSYS,
> +		   DP1000_PERI_MAX_RATE),
> +	DP1000_DIV(DP1000_CLK_SPI_ROOT, "spi_root_clk",
> +		   DP1000_CCR_SPI_OFFSET, DP1000_CLK_SUBSYS,
> +		   DP1000_PERI_MAX_RATE),
> +};
> +
> +static const struct ultrarisc_gate_desc dp1000_gate_clks[] = {
> +	DP1000_GATE(DP1000_CLK_UART0, "uart0_clk", DP1000_CLK_UART_ROOT, 0),
> +	DP1000_GATE(DP1000_CLK_UART1, "uart1_clk", DP1000_CLK_UART_ROOT, 1),
> +	DP1000_GATE(DP1000_CLK_UART2, "uart2_clk", DP1000_CLK_UART_ROOT, 2),
> +	DP1000_GATE(DP1000_CLK_UART3, "uart3_clk", DP1000_CLK_UART_ROOT, 3),
> +	DP1000_GATE(DP1000_CLK_I2C0, "i2c0_clk", DP1000_CLK_I2C_ROOT, 4),
> +	DP1000_GATE(DP1000_CLK_I2C1, "i2c1_clk", DP1000_CLK_I2C_ROOT, 5),
> +	DP1000_GATE(DP1000_CLK_I2C2, "i2c2_clk", DP1000_CLK_I2C_ROOT, 6),
> +	DP1000_GATE(DP1000_CLK_I2C3, "i2c3_clk", DP1000_CLK_I2C_ROOT, 7),
> +	DP1000_GATE(DP1000_CLK_SPI0, "spi0_clk", DP1000_CLK_SPI_ROOT, 8),
> +	DP1000_GATE(DP1000_CLK_SPI1, "spi1_clk", DP1000_CLK_SPI_ROOT, 9),
> +};
> +
> +static const struct ultrarisc_clk_soc_data dp1000_clk_soc_data = {
> +	.num_clks = DP1000_CLK_NUM,
> +	.pll_layout = &dp1000_pll_layout,
> +	.plls = dp1000_plls,
> +	.num_plls = ARRAY_SIZE(dp1000_plls),
> +	.fixed_factors = dp1000_fixed_factor_clks,
> +	.num_fixed_factors = ARRAY_SIZE(dp1000_fixed_factor_clks),
> +	.dividers = dp1000_divider_clks,
> +	.num_dividers = ARRAY_SIZE(dp1000_divider_clks),
> +	.gates = dp1000_gate_clks,
> +	.num_gates = ARRAY_SIZE(dp1000_gate_clks),
> +};
> +
> +static int dp1000_clk_probe(struct platform_device *pdev)
> +{
> +	return ultrarisc_clk_probe(pdev, &dp1000_clk_soc_data);
> +}
> +
> +static const struct of_device_id dp1000_clk_of_match[] = {
> +	{ .compatible = "ultrarisc,dp1000-clk" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, dp1000_clk_of_match);
> +
> +static struct platform_driver dp1000_clk_driver = {
> +	.probe = dp1000_clk_probe,
> +	.driver = {
> +		.name = "ultrarisc-dp1000-clk",
> +		.of_match_table = dp1000_clk_of_match,
> +	},
> +};
> +module_platform_driver(dp1000_clk_driver);
> +
> +MODULE_DESCRIPTION("UltraRISC DP1000 clock controller");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/clk/ultrarisc/clk-ultrarisc.c b/drivers/clk/ultrarisc/clk-ultrarisc.c
> new file mode 100644
> index 000000000000..4ef222348dd7
> --- /dev/null
> +++ b/drivers/clk/ultrarisc/clk-ultrarisc.c
> @@ -0,0 +1,459 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2026 UltraRISC Technology (Shanghai) Co., Ltd.
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/clk-provider.h>
> +#include <linux/io.h>
> +#include <linux/math64.h>
> +#include <linux/module.h>
> +#include <linux/of_clk.h>

This can be dropped.

> +#include <linux/platform_device.h>
> +#include <linux/slab.h>

I think this can be dropped as well.

> +
> +#include "clk-ultrarisc.h"
> +
> +struct ultrarisc_pll_clk {
> +	struct clk_hw hw;
> +	void __iomem *base;
> +	const struct ultrarisc_pll_layout *layout;
> +};
> +
> +struct ultrarisc_divider_clk {
> +	struct clk_divider divider;
> +	struct clk_gate gate;
> +	u32 load_mask;
> +};
> +
> +#define to_ultrarisc_pll_clk(_hw) \
> +	container_of(_hw, struct ultrarisc_pll_clk, hw)
> +
> +static inline struct ultrarisc_divider_clk *
> +to_ultrarisc_divider_clk(struct clk_hw *hw)
> +{
> +	struct clk_divider *divider = to_clk_divider(hw);
> +
> +	return container_of(divider, struct ultrarisc_divider_clk, divider);
> +}
> +
> +static unsigned long ultrarisc_pll_recalc_rate(struct clk_hw *hw,
> +					       unsigned long parent_rate)
> +{
> +	struct ultrarisc_pll_clk *pll = to_ultrarisc_pll_clk(hw);
> +	const struct ultrarisc_pll_layout *layout = pll->layout;
> +	u32 oddiv1_div, oddiv2_div;
> +	u64 mult, rate, den;
> +	u32 frac, m, n;
> +	u32 cfg1, cfg2;
> +
> +	cfg1 = readl_relaxed(pll->base + layout->cfg1_offset);
> +	cfg2 = readl_relaxed(pll->base + layout->cfg2_offset);
> +
> +	frac = field_get(layout->frac_mask, cfg1);
> +	m = field_get(layout->m_mask, cfg2);
> +	n = field_get(layout->n_mask, cfg2);
> +	oddiv1_div = 1U << field_get(layout->oddiv1_mask, cfg2);
> +	oddiv2_div = 1U << field_get(layout->oddiv2_mask, cfg2);
> +
> +	if (!n)
> +		return 0;

Can this if block be moved right after n is assigned above?

> +
> +	/*
> +	 * The output frequency is calculated as:
> +	 * fvco = parent * (m + frac / 2^24) / n
> +	 * fout = fvco / (2^oddiv1_raw * 2^oddiv2_raw)
> +	 *
> +	 * The output divider values are derived from the raw register field
> +	 * values as:

You can now go out to 100 characters on a single line.

> +	 * oddivX_div = 1 << oddivX_raw
> +	 */
> +	mult = ((u64)m << 24) + frac;
> +	rate = (u64)parent_rate * mult;
> +	den = ((u64)n << 24) * oddiv1_div * oddiv2_div;
> +
> +	return div64_u64(rate + (den >> 1), den);
> +}
> +
> +static const struct clk_ops ultrarisc_pll_ro_ops = {
> +	.recalc_rate = ultrarisc_pll_recalc_rate,
> +};
> +
> +static unsigned long
> +ultrarisc_divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
> +{
> +	struct clk_divider *divider = to_clk_divider(hw);
> +	u32 val;
> +
> +	val = readl_relaxed(divider->reg) >> divider->shift;
> +	val &= clk_div_mask(divider->width);
> +
> +	return divider_recalc_rate(hw, parent_rate, val, divider->table,
> +				   divider->flags, divider->width);
> +}
> +
> +static int ultrarisc_divider_determine_rate(struct clk_hw *hw,
> +					    struct clk_rate_request *req)
> +{
> +	struct clk_divider *divider = to_clk_divider(hw);
> +
> +	return divider_determine_rate(hw, req, divider->table, divider->width,
> +				      divider->flags);
> +}
> +
> +static int ultrarisc_divider_set_rate(struct clk_hw *hw, unsigned long rate,
> +				      unsigned long parent_rate)
> +{
> +	struct ultrarisc_divider_clk *divider_clk = to_ultrarisc_divider_clk(hw);
> +	struct clk_divider *divider = &divider_clk->divider;
> +	int value;
> +	u32 val;
> +
> +	value = divider_get_val(rate, parent_rate, divider->table,
> +				divider->width, divider->flags);
> +	if (value < 0)
> +		return value;
> +
> +	scoped_guard(spinlock_irqsave, divider->lock) {
> +		val = readl_relaxed(divider->reg);
> +		val &= ~(clk_div_mask(divider->width) << divider->shift);
> +		val |= value << divider->shift;
> +		writel_relaxed(val, divider->reg);
> +
> +		if (divider_clk->load_mask) {
> +			/*
> +			 * Program the new divider field, then write 1 to the
> +			 * load bit to trigger the update. The load bit is
> +			 * write-triggered and reads back as 0 on this hardware.
> +			 */
> +			writel_relaxed(val | divider_clk->load_mask,
> +				       divider->reg);
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct clk_ops ultrarisc_divider_ops = {
> +	.recalc_rate = ultrarisc_divider_recalc_rate,
> +	.determine_rate = ultrarisc_divider_determine_rate,
> +	.set_rate = ultrarisc_divider_set_rate,
> +};
> +
> +static void ultrarisc_clk_unregister_composite(void *data)
> +{
> +	clk_hw_unregister_composite(data);
> +}
> +
> +static struct clk_hw *
> +ultrarisc_clk_hw_register_composite(struct device *dev, const char *name,
> +				    const char * const *parent_names,
> +				    int num_parents, struct clk_hw *mux_hw,
> +				    const struct clk_ops *mux_ops,
> +				    struct clk_hw *rate_hw,
> +				    const struct clk_ops *rate_ops,
> +				    struct clk_hw *gate_hw,
> +				    const struct clk_ops *gate_ops,
> +				    unsigned long flags)
> +{
> +	struct clk_hw *hw;
> +	int ret;
> +
> +	hw = clk_hw_register_composite(dev, name, parent_names, num_parents,
> +				       mux_hw, mux_ops, rate_hw, rate_ops,
> +				       gate_hw, gate_ops, flags);
> +	if (IS_ERR(hw))
> +		return hw;
> +
> +	ret = devm_add_action_or_reset(dev, ultrarisc_clk_unregister_composite,
> +				       hw);

Use devm_clk_hw_register_composite_pdata()

> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	return hw;
> +}
> +
> +static struct clk_hw *ultrarisc_clk_register_pll(struct device *dev,
> +						 const struct ultrarisc_pll_desc *desc,
> +						 const struct ultrarisc_pll_layout *layout,
> +						 void __iomem *base)
> +{
> +	struct clk_parent_data pdata = { .index = 0 };
> +	struct ultrarisc_pll_clk *pll;
> +	struct clk_init_data init = {
> +		.name = desc->name,
> +		.ops = &ultrarisc_pll_ro_ops,
> +		.parent_data = &pdata,
> +		.num_parents = 1,
> +		.flags = CLK_GET_RATE_NOCACHE,
> +	};
> +	int ret;
> +
> +	pll = devm_kzalloc(dev, sizeof(*pll), GFP_KERNEL);
> +	if (!pll)
> +		return ERR_PTR(-ENOMEM);
> +
> +	pll->base = base;
> +	pll->layout = layout;
> +	pll->hw.init = &init;
> +
> +	ret = devm_clk_hw_register(dev, &pll->hw);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	return &pll->hw;
> +}
> +
> +static struct clk_hw *
> +ultrarisc_clk_register_divider(struct device *dev,
> +			       const struct ultrarisc_divider_desc *desc,
> +			       struct clk_hw *parent_hw, void __iomem *base,
> +			       spinlock_t *lock)
> +{
> +	const char * const parent_names[] = { clk_hw_get_name(parent_hw) };

Moving to devm_clk_hw_register_composite_pdata() will let you drop this
older usage of the parent_names and move to the parent_data.

> +	void __iomem *reg = base + desc->offset;
> +	struct ultrarisc_divider_clk *divider;
> +	const struct clk_ops *gate_ops = NULL;
> +	struct clk_hw *gate_hw = NULL;
> +
> +	if (!desc->div_width)
> +		return ERR_PTR(-EINVAL);
> +
> +	if (!lock)
> +		return ERR_PTR(-EINVAL);
> +
> +	divider = devm_kzalloc(dev, sizeof(*divider), GFP_KERNEL);
> +	if (!divider)
> +		return ERR_PTR(-ENOMEM);
> +
> +	divider->divider.reg = reg;
> +	divider->divider.shift = desc->div_shift;
> +	divider->divider.width = desc->div_width;
> +	divider->divider.flags = desc->divider_flags;
> +	divider->divider.lock = lock;
> +	divider->load_mask = desc->load_mask;
> +
> +	if (desc->gate_bit != ULTRARISC_CLK_NO_GATE) {

As I mentioned elsewhere, nothing sets ULTRARISC_CLK_NO_GATE.

> +		divider->gate.reg = reg;
> +		divider->gate.bit_idx = desc->gate_bit;
> +		divider->gate.flags = desc->gate_flags;
> +		divider->gate.lock = lock;
> +		gate_hw = &divider->gate.hw;
> +		gate_ops = &clk_gate_ops;
> +	}
> +
> +	return ultrarisc_clk_hw_register_composite(dev, desc->name,
> +						   parent_names, 1,
> +						   NULL, NULL,
> +						   &divider->divider.hw,
> +						   &ultrarisc_divider_ops,
> +						   gate_hw, gate_ops,
> +						   CLK_GET_RATE_NOCACHE);
> +}
> +
> +static int ultrarisc_clk_register_fixed_factors(struct device *dev,
> +						struct clk_hw_onecell_data *clk_data,
> +						const struct ultrarisc_clk_soc_data *soc_data)
> +{
> +	u32 i;
> +
> +	for (i = 0; i < soc_data->num_fixed_factors; i++) {
> +		const struct ultrarisc_fixed_factor_desc *desc;
> +		struct clk_hw *parent_hw;
> +		struct clk_hw *hw;
> +
> +		desc = &soc_data->fixed_factors[i];
> +		if (desc->id >= clk_data->num ||
> +		    desc->parent_id >= clk_data->num)

This could be combined onto one line.

> +			return -EINVAL;
> +
> +		parent_hw = clk_data->hws[desc->parent_id];
> +		if (!parent_hw)
> +			return -EINVAL;
> +
> +		hw = devm_clk_hw_register_fixed_factor_parent_hw(dev, desc->name,
> +								 parent_hw,
> +								 CLK_GET_RATE_NOCACHE,

Should all of these clocks be registered with CLK_GET_RATE_NOCACHE? I
see that used in the other registration functions as well.

> +								 desc->mult,
> +								 desc->div);
> +		if (IS_ERR(hw))
> +			return PTR_ERR(hw);
> +
> +		clk_data->hws[desc->id] = hw;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ultrarisc_clk_register_plls(struct platform_device *pdev,
> +				       struct clk_hw_onecell_data *clk_data,
> +				       const struct ultrarisc_clk_soc_data *soc_data,
> +				       void __iomem *base)
> +{
> +	struct device *dev = &pdev->dev;
> +	u32 i;
> +
> +	for (i = 0; i < soc_data->num_plls; i++) {
> +		const struct ultrarisc_pll_desc *desc = &soc_data->plls[i];
> +		struct clk_hw *hw;
> +
> +		if (desc->id >= clk_data->num)
> +			return -EINVAL;

Add dev_error() message here.

> +
> +		hw = ultrarisc_clk_register_pll(dev, desc, soc_data->pll_layout,
> +						base);
> +		if (IS_ERR(hw))
> +			return PTR_ERR(hw);
> +
> +		clk_data->hws[desc->id] = hw;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ultrarisc_clk_register_dividers(struct platform_device *pdev,
> +					   struct clk_hw_onecell_data *clk_data,
> +					   const struct ultrarisc_clk_soc_data *soc_data,
> +					   void __iomem *base,
> +					   spinlock_t *lock)
> +{
> +	struct device *dev = &pdev->dev;
> +	u32 i;
> +
> +	for (i = 0; i < soc_data->num_dividers; i++) {
> +		const struct ultrarisc_divider_desc *desc;
> +		struct clk_hw *parent_hw;
> +		struct clk_hw *hw;
> +
> +		desc = &soc_data->dividers[i];
> +		if (desc->id >= clk_data->num ||
> +		    desc->parent_id >= clk_data->num)

This could be on one line as well. I see some others down below but I'm
not going to call them out separately.

> +			return -EINVAL;
> +
> +		parent_hw = clk_data->hws[desc->parent_id];
> +		if (!parent_hw)
> +			return -EINVAL;
> +
> +		hw = ultrarisc_clk_register_divider(dev, desc, parent_hw, base,
> +						    lock);
> +		if (IS_ERR(hw))
> +			return PTR_ERR(hw);
> +
> +		if (desc->max_rate) {
> +			unsigned long rate;
> +
> +			clk_hw_set_rate_range(hw, 0, desc->max_rate);
> +
> +			rate = clk_hw_get_rate(hw);
> +			if (rate > desc->max_rate)
> +				dev_warn(dev, "%s rate %lu exceeds max %lu\n",
> +					 desc->name, rate, desc->max_rate);
> +		}
> +
> +		clk_data->hws[desc->id] = hw;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ultrarisc_clk_register_gates(struct platform_device *pdev,
> +					struct clk_hw_onecell_data *clk_data,
> +					const struct ultrarisc_clk_soc_data *soc_data,
> +					void __iomem *base,
> +					spinlock_t *lock)
> +{
> +	struct device *dev = &pdev->dev;
> +	u32 i;
> +
> +	for (i = 0; i < soc_data->num_gates; i++) {
> +		const struct ultrarisc_gate_desc *desc;
> +		struct clk_hw *parent_hw;
> +		struct clk_hw *hw;
> +
> +		desc = &soc_data->gates[i];
> +		if (desc->id >= clk_data->num ||
> +		    desc->parent_id >= clk_data->num)
> +			return -EINVAL;
> +
> +		parent_hw = clk_data->hws[desc->parent_id];
> +		if (!parent_hw)
> +			return -EINVAL;
> +
> +		hw = devm_clk_hw_register_gate_parent_hw(dev, desc->name,
> +							 parent_hw,
> +							 CLK_GET_RATE_NOCACHE,
> +							 base + desc->offset,
> +							 desc->gate_bit,
> +							 desc->gate_flags,
> +							 lock);
> +		if (IS_ERR(hw))
> +			return PTR_ERR(hw);
> +
> +		clk_data->hws[desc->id] = hw;
> +	}
> +
> +	return 0;
> +}
> +
> +int ultrarisc_clk_probe(struct platform_device *pdev,
> +			const struct ultrarisc_clk_soc_data *soc_data)
> +{
> +	struct clk_hw_onecell_data *clk_data;
> +	struct device *dev = &pdev->dev;
> +	void __iomem *base;
> +	spinlock_t *lock;
> +	int ret;
> +
> +	if (!soc_data)
> +		return -EINVAL;
> +
> +	lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
> +	if (!lock)
> +		return -ENOMEM;
> +
> +	spin_lock_init(lock);
> +
> +	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws,
> +						 soc_data->num_clks),
> +				GFP_KERNEL);
> +	if (!clk_data)
> +		return -ENOMEM;
> +
> +	clk_data->num = soc_data->num_clks;
> +
> +	base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(base))
> +		return PTR_ERR(base);
> +
> +	ret = ultrarisc_clk_register_plls(pdev, clk_data, soc_data, base);
> +	if (ret)
> +		return ret;
> +
> +	ret = ultrarisc_clk_register_fixed_factors(dev, clk_data, soc_data);
> +	if (ret)
> +		return ret;
> +
> +	ret = ultrarisc_clk_register_dividers(pdev, clk_data, soc_data, base,
> +					      lock);
> +	if (ret)
> +		return ret;
> +
> +	ret = ultrarisc_clk_register_gates(pdev, clk_data, soc_data, base,
> +					   lock);
> +	if (ret)
> +		return ret;
> +
> +	for (int i = 0; i < clk_data->num; i++) {
> +		if (!clk_data->hws[i]) {
> +			dev_err(dev, "missing clock ID %u\n", i);
> +			return -EINVAL;
> +		}
> +	}
> +
> +	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
> +					   clk_data);
> +}
> +EXPORT_SYMBOL_GPL(ultrarisc_clk_probe);

Please put this in a namespace with EXPORT_SYMBOL_NS_GPL(). There's
other examples under drivers/clk.

> +
> +MODULE_DESCRIPTION("UltraRISC clock core driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/clk/ultrarisc/clk-ultrarisc.h b/drivers/clk/ultrarisc/clk-ultrarisc.h
> new file mode 100644
> index 000000000000..1281196bb414
> --- /dev/null
> +++ b/drivers/clk/ultrarisc/clk-ultrarisc.h
> @@ -0,0 +1,73 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef __ULTRARISC_CLK_ULTRARISC_H
> +#define __ULTRARISC_CLK_ULTRARISC_H
> +
> +#include <linux/clk-provider.h>
> +#include <linux/platform_device.h>
> +#include <linux/types.h>
> +
> +#define ULTRARISC_CLK_NO_GATE		(-1)

This is only used in the if statement, and is not set anywhere.

    if (desc->gate_bit != ULTRARISC_CLK_NO_GATE) {

Brian

Re: [PATCH v2 2/2] clk: ultrarisc: add DP1000 clock driver

[Jia Wang]

On 2026-07-07 15:54 -0400, Brian Masney wrote:
> Hi Jia,
> 
> Thanks for the patch.
> 
> On Wed, Jun 17, 2026 at 02:02:55PM +0800, Jia Wang wrote:
> > Add a clock driver for the UltraRISC DP1000 SoC.
> > 
> > The clock tree is driven by a SYSPLL and provides fixed-factor clocks for
> > the subsystem and PCIe, divider-based root clocks for GMAC and the UART,
> > I2C, and SPI blocks, and per-instance gate clocks for UART0-3, I2C0-3,
> > and SPI0-1.
> > 
> > Signed-off-by: Jia Wang <wangjia@ultrarisc.com>
> > ---
> >  MAINTAINERS                           |   1 +
> >  drivers/clk/Kconfig                   |   1 +
> >  drivers/clk/Makefile                  |   1 +
> >  drivers/clk/ultrarisc/Kconfig         |  18 ++
> >  drivers/clk/ultrarisc/Makefile        |   4 +
> >  drivers/clk/ultrarisc/clk-dp1000.c    | 153 ++++++++++++
> >  drivers/clk/ultrarisc/clk-ultrarisc.c | 459 ++++++++++++++++++++++++++++++++++
> >  drivers/clk/ultrarisc/clk-ultrarisc.h |  73 ++++++
> >  8 files changed, 710 insertions(+)
> > 
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index b7e43313c65f..aa5021f30cb5 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -27444,6 +27444,7 @@ M:	Jia Wang <wangjia@ultrarisc.com>
> >  L:	linux-clk@vger.kernel.org
> >  S:	Maintained
> >  F:	Documentation/devicetree/bindings/clock/ultrarisc,dp1000-clk.yaml
> > +F:	drivers/clk/ultrarisc/*
> >  F:	include/dt-bindings/clock/ultrarisc,dp1000-clk.h
> >  
> >  ULTRATRONIK BOARD SUPPORT
> > diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> > index b2efbe9f6acb..75e336858420 100644
> > --- a/drivers/clk/Kconfig
> > +++ b/drivers/clk/Kconfig
> > @@ -535,6 +535,7 @@ source "drivers/clk/tenstorrent/Kconfig"
> >  source "drivers/clk/thead/Kconfig"
> >  source "drivers/clk/stm32/Kconfig"
> >  source "drivers/clk/ti/Kconfig"
> > +source "drivers/clk/ultrarisc/Kconfig"
> >  source "drivers/clk/uniphier/Kconfig"
> >  source "drivers/clk/visconti/Kconfig"
> >  source "drivers/clk/x86/Kconfig"
> > diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> > index a3e2862ebd7e..891272e8e1da 100644
> > --- a/drivers/clk/Makefile
> > +++ b/drivers/clk/Makefile
> > @@ -158,6 +158,7 @@ obj-$(CONFIG_ARCH_TEGRA)		+= tegra/
> >  obj-y					+= tenstorrent/
> >  obj-$(CONFIG_ARCH_THEAD)		+= thead/
> >  obj-y					+= ti/
> > +obj-y					+= ultrarisc/
> >  obj-$(CONFIG_CLK_UNIPHIER)		+= uniphier/
> >  obj-$(CONFIG_ARCH_U8500)		+= ux500/
> >  obj-y					+= versatile/
> > diff --git a/drivers/clk/ultrarisc/Kconfig b/drivers/clk/ultrarisc/Kconfig
> > new file mode 100644
> > index 000000000000..2eecc6ac3119
> > --- /dev/null
> > +++ b/drivers/clk/ultrarisc/Kconfig
> > @@ -0,0 +1,18 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > +
> > +config CLK_ULTRARISC
> > +	tristate
> > +	depends on OF
> > +	depends on ARCH_ULTRARISC || COMPILE_TEST
> > +
> > +config CLK_ULTRARISC_DP1000
> > +	tristate "UltraRISC DP1000 clock controller"
> > +	select CLK_ULTRARISC
> > +	depends on OF && HAS_IOMEM
> > +	depends on ARCH_ULTRARISC || COMPILE_TEST
> > +	default ARCH_ULTRARISC
> > +	help
> > +	  This driver provides the clock controller for the UltraRISC
> > +	  DP1000 SoC. It exposes the PLL output, derived fixed-factor
> > +	  clocks, programmable divider clocks, and peripheral gate
> > +	  clocks to Linux consumers.
> > diff --git a/drivers/clk/ultrarisc/Makefile b/drivers/clk/ultrarisc/Makefile
> > new file mode 100644
> > index 000000000000..b013708c9444
> > --- /dev/null
> > +++ b/drivers/clk/ultrarisc/Makefile
> > @@ -0,0 +1,4 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > +
> > +obj-$(CONFIG_CLK_ULTRARISC) += clk-ultrarisc.o
> > +obj-$(CONFIG_CLK_ULTRARISC_DP1000) += clk-dp1000.o
> > diff --git a/drivers/clk/ultrarisc/clk-dp1000.c b/drivers/clk/ultrarisc/clk-dp1000.c
> > new file mode 100644
> > index 000000000000..33a16df8f189
> > --- /dev/null
> > +++ b/drivers/clk/ultrarisc/clk-dp1000.c
> > @@ -0,0 +1,153 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (C) 2026 UltraRISC Technology (Shanghai) Co., Ltd.
> > + */
> > +
> > +#include <linux/module.h>
> > +
> > +#include <dt-bindings/clock/ultrarisc,dp1000-clk.h>
> > +
> > +#include "clk-ultrarisc.h"
> > +
> > +#define DP1000_PLL_CFG1_OFFSET		0x400
> > +#define DP1000_PLL_CFG2_OFFSET		0x404
> > +
> > +#define DP1000_CCR_UART_OFFSET		0x220
> > +#define DP1000_CCR_I2C_OFFSET		0x224
> > +#define DP1000_CCR_GMAC_OFFSET		0x228
> > +#define DP1000_CCR_SPI_OFFSET		0x22c
> > +#define DP1000_PERI_CLKENA_OFFSET	0x270
> > +
> > +#define DP1000_CCR_LOAD			BIT(16)
> > +
> > +#define DP1000_PERI_MAX_RATE		62500000UL
> > +#define DP1000_CLK_NUM			21
> > +
> > +static const struct ultrarisc_pll_layout dp1000_pll_layout = {
> > +	.cfg1_offset = DP1000_PLL_CFG1_OFFSET,
> > +	.cfg2_offset = DP1000_PLL_CFG2_OFFSET,
> > +	.frac_mask = GENMASK(23, 0),
> > +	.m_mask = GENMASK(23, 16),
> > +	.n_mask = GENMASK(11, 6),
> > +	.oddiv1_mask = GENMASK(4, 3),
> > +	.oddiv2_mask = GENMASK(1, 0),
> > +};
> > +
> > +static const struct ultrarisc_pll_desc dp1000_plls[] = {
> > +	{
> > +		.id = DP1000_CLK_SYSPLL,
> > +		.name = "syspll_clk",
> > +	},
> > +};
> > +
> > +#define DP1000_FIXED_FACTOR(_id, _name, _parent, _mult, _div)	\
> > +	{							\
> > +		.id = (_id),					\
> > +		.name = (_name),				\
> > +		.parent_id = (_parent),				\
> > +		.mult = (_mult),				\
> > +		.div = (_div),					\
> > +	}
> > +
> > +#define DP1000_DIV(_id, _name, _offset, _parent, _max_rate)	\
> > +	{							\
> > +		.id = (_id),					\
> > +		.name = (_name),				\
> > +		.offset = (_offset),				\
> > +		.parent_id = (_parent),				\
> > +		.max_rate = (_max_rate),			\
> > +		.load_mask = DP1000_CCR_LOAD,			\
> > +		.div_shift = 8,					\
> > +		.div_width = 4,					\
> > +		.gate_bit = 0,					\
> > +		.divider_flags = CLK_DIVIDER_ONE_BASED,		\
> > +		.gate_flags = 0,				\
> > +	}
> > +
> > +#define DP1000_GATE(_id, _name, _parent, _bit)		\
> > +	{							\
> > +		.id = (_id),					\
> > +		.name = (_name),				\
> > +		.offset = DP1000_PERI_CLKENA_OFFSET,		\
> > +		.parent_id = (_parent),				\
> > +		.gate_bit = (_bit),				\
> > +		.gate_flags = 0,				\
> > +	}
> > +
> > +static const struct ultrarisc_fixed_factor_desc dp1000_fixed_factor_clks[] = {
> > +	DP1000_FIXED_FACTOR(DP1000_CLK_SYSPLL_DIV2, "syspll_div2_clk",
> > +			    DP1000_CLK_SYSPLL, 1, 2),
> > +	DP1000_FIXED_FACTOR(DP1000_CLK_SUBSYS, "subsys_clk",
> > +			    DP1000_CLK_SYSPLL_DIV2, 1, 2),
> > +	DP1000_FIXED_FACTOR(DP1000_CLK_PCIE_DBI, "pcie_dbi_clk",
> > +			    DP1000_CLK_SYSPLL, 1, 10),
> > +	DP1000_FIXED_FACTOR(DP1000_CLK_PCIEX4_CORE, "pciex4_core_clk",
> > +			    DP1000_CLK_SYSPLL, 1, 2),
> > +	DP1000_FIXED_FACTOR(DP1000_CLK_PCIEX16_CORE, "pciex16_core_clk",
> > +			    DP1000_CLK_SYSPLL, 1, 1),
> > +	DP1000_FIXED_FACTOR(DP1000_CLK_PCIE_AUX, "pcie_aux_clk",
> > +			    DP1000_CLK_SYSPLL, 1, 40),
> > +};
> > +
> > +static const struct ultrarisc_divider_desc dp1000_divider_clks[] = {
> > +	DP1000_DIV(DP1000_CLK_GMAC, "gmac_clk", DP1000_CCR_GMAC_OFFSET,
> > +		   DP1000_CLK_SYSPLL_DIV2, 0),
> > +	DP1000_DIV(DP1000_CLK_UART_ROOT, "uart_root_clk",
> > +		   DP1000_CCR_UART_OFFSET, DP1000_CLK_SUBSYS,
> > +		   DP1000_PERI_MAX_RATE),
> > +	DP1000_DIV(DP1000_CLK_I2C_ROOT, "i2c_root_clk",
> > +		   DP1000_CCR_I2C_OFFSET, DP1000_CLK_SUBSYS,
> > +		   DP1000_PERI_MAX_RATE),
> > +	DP1000_DIV(DP1000_CLK_SPI_ROOT, "spi_root_clk",
> > +		   DP1000_CCR_SPI_OFFSET, DP1000_CLK_SUBSYS,
> > +		   DP1000_PERI_MAX_RATE),
> > +};
> > +
> > +static const struct ultrarisc_gate_desc dp1000_gate_clks[] = {
> > +	DP1000_GATE(DP1000_CLK_UART0, "uart0_clk", DP1000_CLK_UART_ROOT, 0),
> > +	DP1000_GATE(DP1000_CLK_UART1, "uart1_clk", DP1000_CLK_UART_ROOT, 1),
> > +	DP1000_GATE(DP1000_CLK_UART2, "uart2_clk", DP1000_CLK_UART_ROOT, 2),
> > +	DP1000_GATE(DP1000_CLK_UART3, "uart3_clk", DP1000_CLK_UART_ROOT, 3),
> > +	DP1000_GATE(DP1000_CLK_I2C0, "i2c0_clk", DP1000_CLK_I2C_ROOT, 4),
> > +	DP1000_GATE(DP1000_CLK_I2C1, "i2c1_clk", DP1000_CLK_I2C_ROOT, 5),
> > +	DP1000_GATE(DP1000_CLK_I2C2, "i2c2_clk", DP1000_CLK_I2C_ROOT, 6),
> > +	DP1000_GATE(DP1000_CLK_I2C3, "i2c3_clk", DP1000_CLK_I2C_ROOT, 7),
> > +	DP1000_GATE(DP1000_CLK_SPI0, "spi0_clk", DP1000_CLK_SPI_ROOT, 8),
> > +	DP1000_GATE(DP1000_CLK_SPI1, "spi1_clk", DP1000_CLK_SPI_ROOT, 9),
> > +};
> > +
> > +static const struct ultrarisc_clk_soc_data dp1000_clk_soc_data = {
> > +	.num_clks = DP1000_CLK_NUM,
> > +	.pll_layout = &dp1000_pll_layout,
> > +	.plls = dp1000_plls,
> > +	.num_plls = ARRAY_SIZE(dp1000_plls),
> > +	.fixed_factors = dp1000_fixed_factor_clks,
> > +	.num_fixed_factors = ARRAY_SIZE(dp1000_fixed_factor_clks),
> > +	.dividers = dp1000_divider_clks,
> > +	.num_dividers = ARRAY_SIZE(dp1000_divider_clks),
> > +	.gates = dp1000_gate_clks,
> > +	.num_gates = ARRAY_SIZE(dp1000_gate_clks),
> > +};
> > +
> > +static int dp1000_clk_probe(struct platform_device *pdev)
> > +{
> > +	return ultrarisc_clk_probe(pdev, &dp1000_clk_soc_data);
> > +}
> > +
> > +static const struct of_device_id dp1000_clk_of_match[] = {
> > +	{ .compatible = "ultrarisc,dp1000-clk" },
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(of, dp1000_clk_of_match);
> > +
> > +static struct platform_driver dp1000_clk_driver = {
> > +	.probe = dp1000_clk_probe,
> > +	.driver = {
> > +		.name = "ultrarisc-dp1000-clk",
> > +		.of_match_table = dp1000_clk_of_match,
> > +	},
> > +};
> > +module_platform_driver(dp1000_clk_driver);
> > +
> > +MODULE_DESCRIPTION("UltraRISC DP1000 clock controller");
> > +MODULE_LICENSE("GPL");
> > diff --git a/drivers/clk/ultrarisc/clk-ultrarisc.c b/drivers/clk/ultrarisc/clk-ultrarisc.c
> > new file mode 100644
> > index 000000000000..4ef222348dd7
> > --- /dev/null
> > +++ b/drivers/clk/ultrarisc/clk-ultrarisc.c
> > @@ -0,0 +1,459 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (C) 2026 UltraRISC Technology (Shanghai) Co., Ltd.
> > + */
> > +
> > +#include <linux/bitfield.h>
> > +#include <linux/clk-provider.h>
> > +#include <linux/io.h>
> > +#include <linux/math64.h>
> > +#include <linux/module.h>
> > +#include <linux/of_clk.h>
> 
> This can be dropped.
> 
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> 
> I think this can be dropped as well.
>

Thanks for the review.

I'll drop both includes in the next version.
 
> > +
> > +#include "clk-ultrarisc.h"
> > +
> > +struct ultrarisc_pll_clk {
> > +	struct clk_hw hw;
> > +	void __iomem *base;
> > +	const struct ultrarisc_pll_layout *layout;
> > +};
> > +
> > +struct ultrarisc_divider_clk {
> > +	struct clk_divider divider;
> > +	struct clk_gate gate;
> > +	u32 load_mask;
> > +};
> > +
> > +#define to_ultrarisc_pll_clk(_hw) \
> > +	container_of(_hw, struct ultrarisc_pll_clk, hw)
> > +
> > +static inline struct ultrarisc_divider_clk *
> > +to_ultrarisc_divider_clk(struct clk_hw *hw)
> > +{
> > +	struct clk_divider *divider = to_clk_divider(hw);
> > +
> > +	return container_of(divider, struct ultrarisc_divider_clk, divider);
> > +}
> > +
> > +static unsigned long ultrarisc_pll_recalc_rate(struct clk_hw *hw,
> > +					       unsigned long parent_rate)
> > +{
> > +	struct ultrarisc_pll_clk *pll = to_ultrarisc_pll_clk(hw);
> > +	const struct ultrarisc_pll_layout *layout = pll->layout;
> > +	u32 oddiv1_div, oddiv2_div;
> > +	u64 mult, rate, den;
> > +	u32 frac, m, n;
> > +	u32 cfg1, cfg2;
> > +
> > +	cfg1 = readl_relaxed(pll->base + layout->cfg1_offset);
> > +	cfg2 = readl_relaxed(pll->base + layout->cfg2_offset);
> > +
> > +	frac = field_get(layout->frac_mask, cfg1);
> > +	m = field_get(layout->m_mask, cfg2);
> > +	n = field_get(layout->n_mask, cfg2);
> > +	oddiv1_div = 1U << field_get(layout->oddiv1_mask, cfg2);
> > +	oddiv2_div = 1U << field_get(layout->oddiv2_mask, cfg2);
> > +
> > +	if (!n)
> > +		return 0;
> 
> Can this if block be moved right after n is assigned above?
> 

I'll move the check right after n is assigned.

> > +
> > +	/*
> > +	 * The output frequency is calculated as:
> > +	 * fvco = parent * (m + frac / 2^24) / n
> > +	 * fout = fvco / (2^oddiv1_raw * 2^oddiv2_raw)
> > +	 *
> > +	 * The output divider values are derived from the raw register field
> > +	 * values as:
> 
> You can now go out to 100 characters on a single line.
> 

I'll reflow the comment in the next version.

> > +	 * oddivX_div = 1 << oddivX_raw
> > +	 */
> > +	mult = ((u64)m << 24) + frac;
> > +	rate = (u64)parent_rate * mult;
> > +	den = ((u64)n << 24) * oddiv1_div * oddiv2_div;
> > +
> > +	return div64_u64(rate + (den >> 1), den);
> > +}
> > +
> > +static const struct clk_ops ultrarisc_pll_ro_ops = {
> > +	.recalc_rate = ultrarisc_pll_recalc_rate,
> > +};
> > +
> > +static unsigned long
> > +ultrarisc_divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
> > +{
> > +	struct clk_divider *divider = to_clk_divider(hw);
> > +	u32 val;
> > +
> > +	val = readl_relaxed(divider->reg) >> divider->shift;
> > +	val &= clk_div_mask(divider->width);
> > +
> > +	return divider_recalc_rate(hw, parent_rate, val, divider->table,
> > +				   divider->flags, divider->width);
> > +}
> > +
> > +static int ultrarisc_divider_determine_rate(struct clk_hw *hw,
> > +					    struct clk_rate_request *req)
> > +{
> > +	struct clk_divider *divider = to_clk_divider(hw);
> > +
> > +	return divider_determine_rate(hw, req, divider->table, divider->width,
> > +				      divider->flags);
> > +}
> > +
> > +static int ultrarisc_divider_set_rate(struct clk_hw *hw, unsigned long rate,
> > +				      unsigned long parent_rate)
> > +{
> > +	struct ultrarisc_divider_clk *divider_clk = to_ultrarisc_divider_clk(hw);
> > +	struct clk_divider *divider = &divider_clk->divider;
> > +	int value;
> > +	u32 val;
> > +
> > +	value = divider_get_val(rate, parent_rate, divider->table,
> > +				divider->width, divider->flags);
> > +	if (value < 0)
> > +		return value;
> > +
> > +	scoped_guard(spinlock_irqsave, divider->lock) {
> > +		val = readl_relaxed(divider->reg);
> > +		val &= ~(clk_div_mask(divider->width) << divider->shift);
> > +		val |= value << divider->shift;
> > +		writel_relaxed(val, divider->reg);
> > +
> > +		if (divider_clk->load_mask) {
> > +			/*
> > +			 * Program the new divider field, then write 1 to the
> > +			 * load bit to trigger the update. The load bit is
> > +			 * write-triggered and reads back as 0 on this hardware.
> > +			 */
> > +			writel_relaxed(val | divider_clk->load_mask,
> > +				       divider->reg);
> > +		}
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct clk_ops ultrarisc_divider_ops = {
> > +	.recalc_rate = ultrarisc_divider_recalc_rate,
> > +	.determine_rate = ultrarisc_divider_determine_rate,
> > +	.set_rate = ultrarisc_divider_set_rate,
> > +};
> > +
> > +static void ultrarisc_clk_unregister_composite(void *data)
> > +{
> > +	clk_hw_unregister_composite(data);
> > +}
> > +
> > +static struct clk_hw *
> > +ultrarisc_clk_hw_register_composite(struct device *dev, const char *name,
> > +				    const char * const *parent_names,
> > +				    int num_parents, struct clk_hw *mux_hw,
> > +				    const struct clk_ops *mux_ops,
> > +				    struct clk_hw *rate_hw,
> > +				    const struct clk_ops *rate_ops,
> > +				    struct clk_hw *gate_hw,
> > +				    const struct clk_ops *gate_ops,
> > +				    unsigned long flags)
> > +{
> > +	struct clk_hw *hw;
> > +	int ret;
> > +
> > +	hw = clk_hw_register_composite(dev, name, parent_names, num_parents,
> > +				       mux_hw, mux_ops, rate_hw, rate_ops,
> > +				       gate_hw, gate_ops, flags);
> > +	if (IS_ERR(hw))
> > +		return hw;
> > +
> > +	ret = devm_add_action_or_reset(dev, ultrarisc_clk_unregister_composite,
> > +				       hw);
> 
> Use devm_clk_hw_register_composite_pdata()
> 

I originally used clk_hw_register_composite() together with
devm_add_action_or_reset() because devm_clk_hw_register_composite_pdata()
is not currently exported, while this driver can be built as a module.

If exporting it is acceptable, I can add a preparatory patch in this series
to export it and then switch the driver to use that helper.

> > +	if (ret)
> > +		return ERR_PTR(ret);
> > +
> > +	return hw;
> > +}
> > +
> > +static struct clk_hw *ultrarisc_clk_register_pll(struct device *dev,
> > +						 const struct ultrarisc_pll_desc *desc,
> > +						 const struct ultrarisc_pll_layout *layout,
> > +						 void __iomem *base)
> > +{
> > +	struct clk_parent_data pdata = { .index = 0 };
> > +	struct ultrarisc_pll_clk *pll;
> > +	struct clk_init_data init = {
> > +		.name = desc->name,
> > +		.ops = &ultrarisc_pll_ro_ops,
> > +		.parent_data = &pdata,
> > +		.num_parents = 1,
> > +		.flags = CLK_GET_RATE_NOCACHE,
> > +	};
> > +	int ret;
> > +
> > +	pll = devm_kzalloc(dev, sizeof(*pll), GFP_KERNEL);
> > +	if (!pll)
> > +		return ERR_PTR(-ENOMEM);
> > +
> > +	pll->base = base;
> > +	pll->layout = layout;
> > +	pll->hw.init = &init;
> > +
> > +	ret = devm_clk_hw_register(dev, &pll->hw);
> > +	if (ret)
> > +		return ERR_PTR(ret);
> > +
> > +	return &pll->hw;
> > +}
> > +
> > +static struct clk_hw *
> > +ultrarisc_clk_register_divider(struct device *dev,
> > +			       const struct ultrarisc_divider_desc *desc,
> > +			       struct clk_hw *parent_hw, void __iomem *base,
> > +			       spinlock_t *lock)
> > +{
> > +	const char * const parent_names[] = { clk_hw_get_name(parent_hw) };
> 
> Moving to devm_clk_hw_register_composite_pdata() will let you drop this
> older usage of the parent_names and move to the parent_data.
>

Thanks for the suggestion. I'll use parent_data after switching to
devm_clk_hw_register_composite_pdata(), once the helper export is accepted.

> > +	void __iomem *reg = base + desc->offset;
> > +	struct ultrarisc_divider_clk *divider;
> > +	const struct clk_ops *gate_ops = NULL;
> > +	struct clk_hw *gate_hw = NULL;
> > +
> > +	if (!desc->div_width)
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	if (!lock)
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	divider = devm_kzalloc(dev, sizeof(*divider), GFP_KERNEL);
> > +	if (!divider)
> > +		return ERR_PTR(-ENOMEM);
> > +
> > +	divider->divider.reg = reg;
> > +	divider->divider.shift = desc->div_shift;
> > +	divider->divider.width = desc->div_width;
> > +	divider->divider.flags = desc->divider_flags;
> > +	divider->divider.lock = lock;
> > +	divider->load_mask = desc->load_mask;
> > +
> > +	if (desc->gate_bit != ULTRARISC_CLK_NO_GATE) {
> 
> As I mentioned elsewhere, nothing sets ULTRARISC_CLK_NO_GATE.
> 

Yes, all current DP1000 divider clocks have a gate bit, so
ULTRARISC_CLK_NO_GATE is never used. I'll drop the sentinel and always
register them as divider+gate composite clocks.

> > +		divider->gate.reg = reg;
> > +		divider->gate.bit_idx = desc->gate_bit;
> > +		divider->gate.flags = desc->gate_flags;
> > +		divider->gate.lock = lock;
> > +		gate_hw = &divider->gate.hw;
> > +		gate_ops = &clk_gate_ops;
> > +	}
> > +
> > +	return ultrarisc_clk_hw_register_composite(dev, desc->name,
> > +						   parent_names, 1,
> > +						   NULL, NULL,
> > +						   &divider->divider.hw,
> > +						   &ultrarisc_divider_ops,
> > +						   gate_hw, gate_ops,
> > +						   CLK_GET_RATE_NOCACHE);
> > +}
> > +
> > +static int ultrarisc_clk_register_fixed_factors(struct device *dev,
> > +						struct clk_hw_onecell_data *clk_data,
> > +						const struct ultrarisc_clk_soc_data *soc_data)
> > +{
> > +	u32 i;
> > +
> > +	for (i = 0; i < soc_data->num_fixed_factors; i++) {
> > +		const struct ultrarisc_fixed_factor_desc *desc;
> > +		struct clk_hw *parent_hw;
> > +		struct clk_hw *hw;
> > +
> > +		desc = &soc_data->fixed_factors[i];
> > +		if (desc->id >= clk_data->num ||
> > +		    desc->parent_id >= clk_data->num)
> 
> This could be combined onto one line.
>

Sure, I'll fold these onto one line where they fit.

> > +			return -EINVAL;
> > +
> > +		parent_hw = clk_data->hws[desc->parent_id];
> > +		if (!parent_hw)
> > +			return -EINVAL;
> > +
> > +		hw = devm_clk_hw_register_fixed_factor_parent_hw(dev, desc->name,
> > +								 parent_hw,
> > +								 CLK_GET_RATE_NOCACHE,
> 
> Should all of these clocks be registered with CLK_GET_RATE_NOCACHE? I
> see that used in the other registration functions as well.
> 

You're right, this was too broad. Only the PLL clock needs
CLK_GET_RATE_NOCACHE, which is set through clk_init_data.flags because its
recalc_rate() reads the PLL registers. The derived fixed-factor, divider,
and gate clocks don't need it, so I'll drop the flag from those clock
registrations in the next version.

> > +								 desc->mult,
> > +								 desc->div);
> > +		if (IS_ERR(hw))
> > +			return PTR_ERR(hw);
> > +
> > +		clk_data->hws[desc->id] = hw;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int ultrarisc_clk_register_plls(struct platform_device *pdev,
> > +				       struct clk_hw_onecell_data *clk_data,
> > +				       const struct ultrarisc_clk_soc_data *soc_data,
> > +				       void __iomem *base)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	u32 i;
> > +
> > +	for (i = 0; i < soc_data->num_plls; i++) {
> > +		const struct ultrarisc_pll_desc *desc = &soc_data->plls[i];
> > +		struct clk_hw *hw;
> > +
> > +		if (desc->id >= clk_data->num)
> > +			return -EINVAL;
> 
> Add dev_error() message here.
> 

I'll add a dev_err() for the invalid PLL clock ID case.

> > +
> > +		hw = ultrarisc_clk_register_pll(dev, desc, soc_data->pll_layout,
> > +						base);
> > +		if (IS_ERR(hw))
> > +			return PTR_ERR(hw);
> > +
> > +		clk_data->hws[desc->id] = hw;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int ultrarisc_clk_register_dividers(struct platform_device *pdev,
> > +					   struct clk_hw_onecell_data *clk_data,
> > +					   const struct ultrarisc_clk_soc_data *soc_data,
> > +					   void __iomem *base,
> > +					   spinlock_t *lock)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	u32 i;
> > +
> > +	for (i = 0; i < soc_data->num_dividers; i++) {
> > +		const struct ultrarisc_divider_desc *desc;
> > +		struct clk_hw *parent_hw;
> > +		struct clk_hw *hw;
> > +
> > +		desc = &soc_data->dividers[i];
> > +		if (desc->id >= clk_data->num ||
> > +		    desc->parent_id >= clk_data->num)
> 
> This could be on one line as well. I see some others down below but I'm
> not going to call them out separately.
> 

I'll fold the similar cases where it doesn't hurt readability.

> > +			return -EINVAL;
> > +
> > +		parent_hw = clk_data->hws[desc->parent_id];
> > +		if (!parent_hw)
> > +			return -EINVAL;
> > +
> > +		hw = ultrarisc_clk_register_divider(dev, desc, parent_hw, base,
> > +						    lock);
> > +		if (IS_ERR(hw))
> > +			return PTR_ERR(hw);
> > +
> > +		if (desc->max_rate) {
> > +			unsigned long rate;
> > +
> > +			clk_hw_set_rate_range(hw, 0, desc->max_rate);
> > +
> > +			rate = clk_hw_get_rate(hw);
> > +			if (rate > desc->max_rate)
> > +				dev_warn(dev, "%s rate %lu exceeds max %lu\n",
> > +					 desc->name, rate, desc->max_rate);
> > +		}
> > +
> > +		clk_data->hws[desc->id] = hw;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int ultrarisc_clk_register_gates(struct platform_device *pdev,
> > +					struct clk_hw_onecell_data *clk_data,
> > +					const struct ultrarisc_clk_soc_data *soc_data,
> > +					void __iomem *base,
> > +					spinlock_t *lock)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	u32 i;
> > +
> > +	for (i = 0; i < soc_data->num_gates; i++) {
> > +		const struct ultrarisc_gate_desc *desc;
> > +		struct clk_hw *parent_hw;
> > +		struct clk_hw *hw;
> > +
> > +		desc = &soc_data->gates[i];
> > +		if (desc->id >= clk_data->num ||
> > +		    desc->parent_id >= clk_data->num)
> > +			return -EINVAL;
> > +
> > +		parent_hw = clk_data->hws[desc->parent_id];
> > +		if (!parent_hw)
> > +			return -EINVAL;
> > +
> > +		hw = devm_clk_hw_register_gate_parent_hw(dev, desc->name,
> > +							 parent_hw,
> > +							 CLK_GET_RATE_NOCACHE,
> > +							 base + desc->offset,
> > +							 desc->gate_bit,
> > +							 desc->gate_flags,
> > +							 lock);
> > +		if (IS_ERR(hw))
> > +			return PTR_ERR(hw);
> > +
> > +		clk_data->hws[desc->id] = hw;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +int ultrarisc_clk_probe(struct platform_device *pdev,
> > +			const struct ultrarisc_clk_soc_data *soc_data)
> > +{
> > +	struct clk_hw_onecell_data *clk_data;
> > +	struct device *dev = &pdev->dev;
> > +	void __iomem *base;
> > +	spinlock_t *lock;
> > +	int ret;
> > +
> > +	if (!soc_data)
> > +		return -EINVAL;
> > +
> > +	lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
> > +	if (!lock)
> > +		return -ENOMEM;
> > +
> > +	spin_lock_init(lock);
> > +
> > +	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws,
> > +						 soc_data->num_clks),
> > +				GFP_KERNEL);
> > +	if (!clk_data)
> > +		return -ENOMEM;
> > +
> > +	clk_data->num = soc_data->num_clks;
> > +
> > +	base = devm_platform_ioremap_resource(pdev, 0);
> > +	if (IS_ERR(base))
> > +		return PTR_ERR(base);
> > +
> > +	ret = ultrarisc_clk_register_plls(pdev, clk_data, soc_data, base);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = ultrarisc_clk_register_fixed_factors(dev, clk_data, soc_data);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = ultrarisc_clk_register_dividers(pdev, clk_data, soc_data, base,
> > +					      lock);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = ultrarisc_clk_register_gates(pdev, clk_data, soc_data, base,
> > +					   lock);
> > +	if (ret)
> > +		return ret;
> > +
> > +	for (int i = 0; i < clk_data->num; i++) {
> > +		if (!clk_data->hws[i]) {
> > +			dev_err(dev, "missing clock ID %u\n", i);
> > +			return -EINVAL;
> > +		}
> > +	}
> > +
> > +	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
> > +					   clk_data);
> > +}
> > +EXPORT_SYMBOL_GPL(ultrarisc_clk_probe);
> 
> Please put this in a namespace with EXPORT_SYMBOL_NS_GPL(). There's
> other examples under drivers/clk.
> 

I'll export it under a CLK_ULTRARISC namespace.

> > +
> > +MODULE_DESCRIPTION("UltraRISC clock core driver");
> > +MODULE_LICENSE("GPL");
> > diff --git a/drivers/clk/ultrarisc/clk-ultrarisc.h b/drivers/clk/ultrarisc/clk-ultrarisc.h
> > new file mode 100644
> > index 000000000000..1281196bb414
> > --- /dev/null
> > +++ b/drivers/clk/ultrarisc/clk-ultrarisc.h
> > @@ -0,0 +1,73 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +#ifndef __ULTRARISC_CLK_ULTRARISC_H
> > +#define __ULTRARISC_CLK_ULTRARISC_H
> > +
> > +#include <linux/clk-provider.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/types.h>
> > +
> > +#define ULTRARISC_CLK_NO_GATE		(-1)
> 
> This is only used in the if statement, and is not set anywhere.
> 
>     if (desc->gate_bit != ULTRARISC_CLK_NO_GATE) {
>

Right, I'll remove it in the next version.
 
> Brian
> 
> 

Best regards,
Jia Wang

Re: [PATCH v2 2/2] clk: ultrarisc: add DP1000 clock driver

[Brian Masney]

On Wed, Jul 08, 2026 at 03:53:06PM +0800, Jia Wang wrote:
> On 2026-07-07 15:54 -0400, Brian Masney wrote:
> > On Wed, Jun 17, 2026 at 02:02:55PM +0800, Jia Wang wrote:
> > > +static struct clk_hw *
> > > +ultrarisc_clk_hw_register_composite(struct device *dev, const char *name,
> > > +				    const char * const *parent_names,
> > > +				    int num_parents, struct clk_hw *mux_hw,
> > > +				    const struct clk_ops *mux_ops,
> > > +				    struct clk_hw *rate_hw,
> > > +				    const struct clk_ops *rate_ops,
> > > +				    struct clk_hw *gate_hw,
> > > +				    const struct clk_ops *gate_ops,
> > > +				    unsigned long flags)
> > > +{
> > > +	struct clk_hw *hw;
> > > +	int ret;
> > > +
> > > +	hw = clk_hw_register_composite(dev, name, parent_names, num_parents,
> > > +				       mux_hw, mux_ops, rate_hw, rate_ops,
> > > +				       gate_hw, gate_ops, flags);
> > > +	if (IS_ERR(hw))
> > > +		return hw;
> > > +
> > > +	ret = devm_add_action_or_reset(dev, ultrarisc_clk_unregister_composite,
> > > +				       hw);
> > 
> > Use devm_clk_hw_register_composite_pdata()
> > 
> 
> I originally used clk_hw_register_composite() together with
> devm_add_action_or_reset() because devm_clk_hw_register_composite_pdata()
> is not currently exported, while this driver can be built as a module.
> 
> If exporting it is acceptable, I can add a preparatory patch in this series
> to export it and then switch the driver to use that helper.

Yes, I think that exporting this makes sense.

Brian