[PATCH v2 0/8] Add clock support for Loongson 2K0300 SoC

[PATCH v2 0/8] Add clock support for Loongson 2K0300 SoC

[Yao Zi]

This series adds support for Loongson 2K0300's clock controller.
Loongson 2 clock driver is prepared to support more clock variants and
its flexibility is improved. All clock hardwares except the output one
for GMAC module are then defined.

A clock tree dump could be obtained here[1]. This series depends on v3
of series "Initial support for CTCISZ Forever Pi"[2] to apply.

[1]: https://gist.github.com/ziyao233/160bb4693e7758b2a2a996d4510b7247
[2]: https://lore.kernel.org/all/20250523095408.25919-1-ziyao@disroot.org/

Changed from v1:
- Fold loongson,ls2k0300-clk.yaml into loongson,ls2k-clk.yaml
- Include the new binding header in MAINTAINERS
- Link to v1: https://lore.kernel.org/all/20250523104552.32742-1-ziyao@disroot.org/

Yao Zi (8):
  dt-bindings: clock: loongson2: Add Loongson 2K0300 compatible
  clk: loongson2: Allow specifying clock flags for gate clock
  clk: loongson2: Support scale clocks with an alternative mode
  clk: loongson2: Allow zero divisors for dividers
  clk: loongson2: Avoid hardcoding firmware name of the reference clock
  clk: loongson2: Add clock definitions for Loongson 2K0300 SoC
  LoongArch: dts: Add clock tree for Loongson 2K0300
  LoongArch: dts: Remove clock-frquency from UART0 of CTCISZ Forever Pi

 .../bindings/clock/loongson,ls2k-clk.yaml     |  26 +++-
 MAINTAINERS                                   |   1 +
 .../dts/loongson-2k0300-ctcisz-forever-pi.dts |   1 -
 arch/loongarch/boot/dts/loongson-2k0300.dtsi  |  17 ++-
 drivers/clk/clk-loongson2.c                   | 124 +++++++++++++++---
 .../dt-bindings/clock/loongson,ls2k0300-clk.h |  54 ++++++++
 6 files changed, 193 insertions(+), 30 deletions(-)
 create mode 100644 include/dt-bindings/clock/loongson,ls2k0300-clk.h

-- 
2.49.0

[PATCH v2 1/8] dt-bindings: clock: loongson2: Add Loongson 2K0300 compatible

[Yao Zi]

Document the clock controller shipped in Loongson 2K0300 SoC, which
generates various clock signals for SoC peripherals.

Differing from previous generations of SoCs, 2K0300 requires a 120MHz
external clock input, and a separate dt-binding header is used for
cleanness.

Signed-off-by: Yao Zi <ziyao@disroot.org>
---
 .../bindings/clock/loongson,ls2k-clk.yaml     | 26 ++++++---
 MAINTAINERS                                   |  1 +
 .../dt-bindings/clock/loongson,ls2k0300-clk.h | 54 +++++++++++++++++++
 3 files changed, 75 insertions(+), 6 deletions(-)
 create mode 100644 include/dt-bindings/clock/loongson,ls2k0300-clk.h

diff --git a/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml b/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
index 4f79cdb417ab..3e0a894cfb2f 100644
--- a/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
+++ b/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
@@ -16,6 +16,7 @@ description: |
 properties:
   compatible:
     enum:
+      - loongson,ls2k0300-clk
       - loongson,ls2k0500-clk
       - loongson,ls2k-clk  # This is for Loongson-2K1000
       - loongson,ls2k2000-clk
@@ -24,19 +25,32 @@ properties:
     maxItems: 1
 
   clocks:
-    items:
-      - description: 100m ref
+    maxItems: 1
 
-  clock-names:
-    items:
-      - const: ref_100m
+  clock-names: true
 
   '#clock-cells':
     const: 1
     description:
       The clock consumer should specify the desired clock by having the clock
       ID in its "clocks" phandle cell. See include/dt-bindings/clock/loongson,ls2k-clk.h
-      for the full list of Loongson-2 SoC clock IDs.
+      and include/dt-bindings/clock/loongson,ls2k0300-clk.h for the full list of
+      Loongson-2 SoC clock IDs.
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: loongson,ls2k0300-clk
+    then:
+      properties:
+        clock-names:
+          const: ref_120m
+    else:
+      properties:
+        clock-names:
+          const: ref_100m
 
 required:
   - compatible
diff --git a/MAINTAINERS b/MAINTAINERS
index dd844ac8d910..9b7c4b2b7f58 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13954,6 +13954,7 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
 F:	drivers/clk/clk-loongson2.c
 F:	include/dt-bindings/clock/loongson,ls2k-clk.h
+F:	include/dt-bindings/clock/loongson,ls2k0300-clk.h
 
 LOONGSON SPI DRIVER
 M:	Yinbo Zhu <zhuyinbo@loongson.cn>
diff --git a/include/dt-bindings/clock/loongson,ls2k0300-clk.h b/include/dt-bindings/clock/loongson,ls2k0300-clk.h
new file mode 100644
index 000000000000..5e8f7b2f33f2
--- /dev/null
+++ b/include/dt-bindings/clock/loongson,ls2k0300-clk.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR MIT) */
+/*
+ * Copyright (C) 2025 Yao Zi <ziyao@disroot.org>
+ */
+#ifndef _DT_BINDINGS_CLK_LOONGSON_LS2K300_H_
+#define _DT_BINDINGS_CLK_LOONGSON_LS2K300_H_
+
+/* Derivied from REFCLK */
+#define LS2K0300_CLK_STABLE			0
+#define LS2K0300_PLL_NODE			1
+#define LS2K0300_PLL_DDR			2
+#define LS2K0300_PLL_PIX			3
+#define LS2K0300_CLK_THSENS			4
+
+/* Derived from PLL_NODE */
+#define LS2K0300_CLK_NODE_DIV			5
+#define LS2K0300_CLK_NODE_PLL_GATE		6
+#define LS2K0300_CLK_NODE_SCALE			7
+#define LS2K0300_CLK_NODE_GATE			8
+#define LS2K0300_CLK_GMAC_DIV			9
+#define LS2K0300_CLK_GMAC_GATE			10
+#define LS2K0300_CLK_I2S_DIV			11
+#define LS2K0300_CLK_I2S_SCALE			12
+#define LS2K0300_CLK_I2S_GATE			13
+
+/* Derived from PLL_DDR */
+#define LS2K0300_CLK_DDR_DIV			14
+#define LS2K0300_CLK_DDR_GATE			15
+#define LS2K0300_CLK_NET_DIV			16
+#define LS2K0300_CLK_NET_GATE			17
+#define LS2K0300_CLK_DEV_DIV			18
+#define LS2K0300_CLK_DEV_GATE			19
+
+/* Derived from PLL_PIX */
+#define LS2K0300_CLK_PIX_DIV			20
+#define LS2K0300_CLK_PIX_PLL_GATE		21
+#define LS2K0300_CLK_PIX_SCALE			22
+#define LS2K0300_CLK_PIX_GATE			23
+#define LS2K0300_CLK_GMACBP_DIV			24
+#define LS2K0300_CLK_GMACBP_GATE		25
+
+/* Derived from CLK_DEV */
+#define LS2K0300_CLK_USB_SCALE			26
+#define LS2K0300_CLK_USB_GATE			27
+#define LS2K0300_CLK_APB_SCALE			28
+#define LS2K0300_CLK_APB_GATE			29
+#define LS2K0300_CLK_BOOT_SCALE			30
+#define LS2K0300_CLK_BOOT_GATE			31
+#define LS2K0300_CLK_SDIO_SCALE			32
+#define LS2K0300_CLK_SDIO_GATE			33
+
+#define LS2K0300_CLK_GMAC_IN			34
+
+#endif // _DT_BINDINGS_CLK_LOONGSON_LS2K300_H_
-- 
2.49.0

Re: [PATCH v2 1/8] dt-bindings: clock: loongson2: Add Loongson 2K0300 compatible

[Krzysztof Kozlowski]

On Tue, Jun 17, 2025 at 04:24:19PM +0000, Yao Zi wrote:
> Document the clock controller shipped in Loongson 2K0300 SoC, which
> generates various clock signals for SoC peripherals.
> 
> Differing from previous generations of SoCs, 2K0300 requires a 120MHz
> external clock input, and a separate dt-binding header is used for
> cleanness.
> 
> Signed-off-by: Yao Zi <ziyao@disroot.org>
> ---
>  .../bindings/clock/loongson,ls2k-clk.yaml     | 26 ++++++---
>  MAINTAINERS                                   |  1 +
>  .../dt-bindings/clock/loongson,ls2k0300-clk.h | 54 +++++++++++++++++++
>  3 files changed, 75 insertions(+), 6 deletions(-)
>  create mode 100644 include/dt-bindings/clock/loongson,ls2k0300-clk.h
> 
> diff --git a/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml b/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
> index 4f79cdb417ab..3e0a894cfb2f 100644
> --- a/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
> +++ b/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
> @@ -16,6 +16,7 @@ description: |
>  properties:
>    compatible:
>      enum:
> +      - loongson,ls2k0300-clk
>        - loongson,ls2k0500-clk
>        - loongson,ls2k-clk  # This is for Loongson-2K1000
>        - loongson,ls2k2000-clk
> @@ -24,19 +25,32 @@ properties:
>      maxItems: 1
>  
>    clocks:
> -    items:
> -      - description: 100m ref
> +    maxItems: 1
>  
> -  clock-names:
> -    items:
> -      - const: ref_100m
> +  clock-names: true

No. How does this implement my comment?

It makes no sense, why 100m even appeared here. I already objected last
time!


>  
>    '#clock-cells':
>      const: 1
>      description:
>        The clock consumer should specify the desired clock by having the clock
>        ID in its "clocks" phandle cell. See include/dt-bindings/clock/loongson,ls2k-clk.h
> -      for the full list of Loongson-2 SoC clock IDs.
> +      and include/dt-bindings/clock/loongson,ls2k0300-clk.h for the full list of
> +      Loongson-2 SoC clock IDs.
> +
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: loongson,ls2k0300-clk
> +    then:
> +      properties:
> +        clock-names:
> +          const: ref_120m

NAK, stop doing this pattern. You already got comment on this.

Best regards,
Krzysztof

Re: [PATCH v2 1/8] dt-bindings: clock: loongson2: Add Loongson 2K0300 compatible

[Yao Zi]

On Fri, Jun 27, 2025 at 10:03:53AM +0200, Krzysztof Kozlowski wrote:
> On Tue, Jun 17, 2025 at 04:24:19PM +0000, Yao Zi wrote:
> > Document the clock controller shipped in Loongson 2K0300 SoC, which
> > generates various clock signals for SoC peripherals.
> > 
> > Differing from previous generations of SoCs, 2K0300 requires a 120MHz
> > external clock input, and a separate dt-binding header is used for
> > cleanness.
> > 
> > Signed-off-by: Yao Zi <ziyao@disroot.org>
> > ---
> >  .../bindings/clock/loongson,ls2k-clk.yaml     | 26 ++++++---
> >  MAINTAINERS                                   |  1 +
> >  .../dt-bindings/clock/loongson,ls2k0300-clk.h | 54 +++++++++++++++++++
> >  3 files changed, 75 insertions(+), 6 deletions(-)
> >  create mode 100644 include/dt-bindings/clock/loongson,ls2k0300-clk.h
> > 
> > diff --git a/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml b/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
> > index 4f79cdb417ab..3e0a894cfb2f 100644
> > --- a/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
> > +++ b/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
> > @@ -16,6 +16,7 @@ description: |
> >  properties:
> >    compatible:
> >      enum:
> > +      - loongson,ls2k0300-clk
> >        - loongson,ls2k0500-clk
> >        - loongson,ls2k-clk  # This is for Loongson-2K1000
> >        - loongson,ls2k2000-clk
> > @@ -24,19 +25,32 @@ properties:
> >      maxItems: 1
> >  
> >    clocks:
> > -    items:
> > -      - description: 100m ref
> > +    maxItems: 1
> >  
> > -  clock-names:
> > -    items:
> > -      - const: ref_100m
> > +  clock-names: true
> 
> No. How does this implement my comment?

I'm sorry that I forgot about the suggestion of dropping clock-names for
the new compatible.

Is it acceptable to remove the description of clocks property, keep
clock-names property as-is, and use an allOf block to disallow
clocks-names for the new 2K0300 compatible? Thanks for your explanation.

> It makes no sense, why 100m even appeared here. I already objected last
> time!
> 
> 
> >  
> >    '#clock-cells':
> >      const: 1
> >      description:
> >        The clock consumer should specify the desired clock by having the clock
> >        ID in its "clocks" phandle cell. See include/dt-bindings/clock/loongson,ls2k-clk.h
> > -      for the full list of Loongson-2 SoC clock IDs.
> > +      and include/dt-bindings/clock/loongson,ls2k0300-clk.h for the full list of
> > +      Loongson-2 SoC clock IDs.
> > +
> > +allOf:
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            const: loongson,ls2k0300-clk
> > +    then:
> > +      properties:
> > +        clock-names:
> > +          const: ref_120m
> 
> NAK, stop doing this pattern. You already got comment on this.

Oops, I missed the comment about dropping the frequency (or the full
clock-names property) from clock-names when writing v2, and I've decided
to drop the clock-names property completely for the 2K0300 compatible.

Sorry again for my mistake.

> Best regards,
> Krzysztof
> 
> 

Best regards,
Yao Zi

Re: [PATCH v2 1/8] dt-bindings: clock: loongson2: Add Loongson 2K0300 compatible

[Yao Zi]

On Fri, Jun 27, 2025 at 11:52:41AM +0000, Yao Zi wrote:
> On Fri, Jun 27, 2025 at 10:03:53AM +0200, Krzysztof Kozlowski wrote:
> > On Tue, Jun 17, 2025 at 04:24:19PM +0000, Yao Zi wrote:
> > > Document the clock controller shipped in Loongson 2K0300 SoC, which
> > > generates various clock signals for SoC peripherals.
> > > 
> > > Differing from previous generations of SoCs, 2K0300 requires a 120MHz
> > > external clock input, and a separate dt-binding header is used for
> > > cleanness.
> > > 
> > > Signed-off-by: Yao Zi <ziyao@disroot.org>
> > > ---
> > >  .../bindings/clock/loongson,ls2k-clk.yaml     | 26 ++++++---
> > >  MAINTAINERS                                   |  1 +
> > >  .../dt-bindings/clock/loongson,ls2k0300-clk.h | 54 +++++++++++++++++++
> > >  3 files changed, 75 insertions(+), 6 deletions(-)
> > >  create mode 100644 include/dt-bindings/clock/loongson,ls2k0300-clk.h
> > > 
> > > diff --git a/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml b/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
> > > index 4f79cdb417ab..3e0a894cfb2f 100644
> > > --- a/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
> > > +++ b/Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
> > > @@ -16,6 +16,7 @@ description: |
> > >  properties:
> > >    compatible:
> > >      enum:
> > > +      - loongson,ls2k0300-clk
> > >        - loongson,ls2k0500-clk
> > >        - loongson,ls2k-clk  # This is for Loongson-2K1000
> > >        - loongson,ls2k2000-clk
> > > @@ -24,19 +25,32 @@ properties:
> > >      maxItems: 1
> > >  
> > >    clocks:
> > > -    items:
> > > -      - description: 100m ref
> > > +    maxItems: 1
> > >  
> > > -  clock-names:
> > > -    items:
> > > -      - const: ref_100m
> > > +  clock-names: true
> > 
> > No. How does this implement my comment?

Hi Krzysztof,

> I'm sorry that I forgot about the suggestion of dropping clock-names for
> the new compatible.
> 
> Is it acceptable to remove the description of clocks property, keep
> clock-names property as-is, and use an allOf block to disallow
> clocks-names for the new 2K0300 compatible? Thanks for your explanation.

Could you please provide some further comments on this? The schema will
look like,

	clocks:
	  maxItems: 1

	clock-names:
	  items:
	    - const: ref_100m

	...

	allOf:
	  - if:
	      properties:
	        compatible:
	          contains:
	            const: loongson,ls2k0300-clk
	    then:
	      properties:
	        clock-names: false
	    else:
	      required:
	        - clock-names

Thanks for your time and suggestion.

> > It makes no sense, why 100m even appeared here. I already objected last
> > time!
> > 
> > >  
> > >    '#clock-cells':
> > >      const: 1
> > >      description:
> > >        The clock consumer should specify the desired clock by having the clock
> > >        ID in its "clocks" phandle cell. See include/dt-bindings/clock/loongson,ls2k-clk.h
> > > -      for the full list of Loongson-2 SoC clock IDs.
> > > +      and include/dt-bindings/clock/loongson,ls2k0300-clk.h for the full list of
> > > +      Loongson-2 SoC clock IDs.
> > > +
> > > +allOf:
> > > +  - if:
> > > +      properties:
> > > +        compatible:
> > > +          contains:
> > > +            const: loongson,ls2k0300-clk
> > > +    then:
> > > +      properties:
> > > +        clock-names:
> > > +          const: ref_120m
> > 
> > NAK, stop doing this pattern. You already got comment on this.
> 
> Oops, I missed the comment about dropping the frequency (or the full
> clock-names property) from clock-names when writing v2, and I've decided
> to drop the clock-names property completely for the 2K0300 compatible.
> 
> Sorry again for my mistake.
> 
> > Best regards,
> > Krzysztof
> > 
> > 
> 
> Best regards,
> Yao Zi
> 

Regards,
Yao Zi

[PATCH v2 2/8] clk: loongson2: Allow specifying clock flags for gate clock

[Yao Zi]

Some gate clocks need to be supplied with flags, e.g., it may be
required to specify CLK_IS_CRTICAL for CPU clocks.

Add a field to loongson2_clk_board_info for representing clock flags,
and specify it when registering gate clocks. A new helper macro,
CLK_GATE_FLAGS, is added to simplify definitions.

Signed-off-by: Yao Zi <ziyao@disroot.org>
---
 drivers/clk/clk-loongson2.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-loongson2.c b/drivers/clk/clk-loongson2.c
index 27e632edd484..cc3fb13e770f 100644
--- a/drivers/clk/clk-loongson2.c
+++ b/drivers/clk/clk-loongson2.c
@@ -50,6 +50,7 @@ struct loongson2_clk_board_info {
 	const char *name;
 	const char *parent_name;
 	unsigned long fixed_rate;
+	unsigned long flags;
 	u8 reg_offset;
 	u8 div_shift;
 	u8 div_width;
@@ -105,6 +106,18 @@ struct loongson2_clk_board_info {
 		.bit_idx	= _bidx,			\
 	}
 
+#define CLK_GATE_FLAGS(_id, _name, _pname, _offset, _bidx,	\
+		       _flags)					\
+	{							\
+		.id		= _id,				\
+		.type		= CLK_TYPE_GATE,		\
+		.name		= _name,			\
+		.parent_name	= _pname,			\
+		.reg_offset	= _offset,			\
+		.bit_idx	= _bidx,			\
+		.flags		= _flags			\
+	}
+
 #define CLK_FIXED(_id, _name, _pname, _rate)			\
 	{							\
 		.id		= _id,				\
@@ -332,7 +345,8 @@ static int loongson2_clk_probe(struct platform_device *pdev)
 							  &clp->clk_lock);
 			break;
 		case CLK_TYPE_GATE:
-			hw = devm_clk_hw_register_gate(dev, p->name, p->parent_name, 0,
+			hw = devm_clk_hw_register_gate(dev, p->name, p->parent_name,
+						       p->flags,
 						       clp->base + p->reg_offset,
 						       p->bit_idx, 0,
 						       &clp->clk_lock);
-- 
2.49.0

[PATCH v2 3/8] clk: loongson2: Support scale clocks with an alternative mode

[Yao Zi]

Loongson 2K0300 and 2K1500 ship scale clocks with an alternative mode.
There's one mode bit in clock configuration register indicating the
operation mode.

When mode bit is unset, the scale clock acts the same as previous
generation of scale clocks. When it's set, a different equation for
calculating result frequency, Fout = Fin / (scale + 1), is used.

This patch adds frequency calculation support for the scale clock
variant. A helper macro, CLK_SCALE_MODE, is added to simplify
definitions.

Signed-off-by: Yao Zi <ziyao@disroot.org>
---
 drivers/clk/clk-loongson2.c | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/clk-loongson2.c b/drivers/clk/clk-loongson2.c
index cc3fb13e770f..bba97270376c 100644
--- a/drivers/clk/clk-loongson2.c
+++ b/drivers/clk/clk-loongson2.c
@@ -42,6 +42,7 @@ struct loongson2_clk_data {
 	u8 div_width;
 	u8 mult_shift;
 	u8 mult_width;
+	u8 bit_idx;
 };
 
 struct loongson2_clk_board_info {
@@ -96,6 +97,19 @@ struct loongson2_clk_board_info {
 		.div_width	= _dwidth,			\
 	}
 
+#define CLK_SCALE_MODE(_id, _name, _pname, _offset,		\
+		  _dshift, _dwidth, _midx)			\
+	{							\
+		.id		= _id,				\
+		.type		= CLK_TYPE_SCALE,		\
+		.name		= _name,			\
+		.parent_name	= _pname,			\
+		.reg_offset	= _offset,			\
+		.div_shift	= _dshift,			\
+		.div_width	= _dwidth,			\
+		.bit_idx	= _midx + 1,			\
+	}
+
 #define CLK_GATE(_id, _name, _pname, _offset, _bidx)		\
 	{							\
 		.id		= _id,				\
@@ -243,13 +257,18 @@ static const struct clk_ops loongson2_pll_recalc_ops = {
 static unsigned long loongson2_freqscale_recalc_rate(struct clk_hw *hw,
 						     unsigned long parent_rate)
 {
-	u64 val, mult;
+	u64 val, scale;
+	u32 mode = 0;
 	struct loongson2_clk_data *clk = to_loongson2_clk(hw);
 
 	val  = readq(clk->reg);
-	mult = loongson2_rate_part(val, clk->div_shift, clk->div_width) + 1;
+	scale = loongson2_rate_part(val, clk->div_shift, clk->div_width) + 1;
+
+	if (clk->bit_idx)
+		mode = val & BIT(clk->bit_idx - 1);
 
-	return div_u64((u64)parent_rate * mult, 8);
+	return mode == 0 ? div_u64((u64)parent_rate * scale, 8) :
+			   div_u64((u64)parent_rate, scale);
 }
 
 static const struct clk_ops loongson2_freqscale_recalc_ops = {
@@ -284,6 +303,7 @@ static struct clk_hw *loongson2_clk_register(struct loongson2_clk_provider *clp,
 	clk->div_width	= cld->div_width;
 	clk->mult_shift	= cld->mult_shift;
 	clk->mult_width	= cld->mult_width;
+	clk->bit_idx	= cld->bit_idx;
 	clk->hw.init	= &init;
 
 	hw = &clk->hw;
-- 
2.49.0

[PATCH v2 4/8] clk: loongson2: Allow zero divisors for dividers

[Yao Zi]

Loongson 2K0300 and 2K0500 ship divider clocks which allows zero
divisors, in which case the divider acts the same as one is specified.

Let's pass CLK_DIVIDER_ALLOW_ZERO when registering divider clocks to
prepare for future introduction of these clocks.

Signed-off-by: Yao Zi <ziyao@disroot.org>
---
 drivers/clk/clk-loongson2.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-loongson2.c b/drivers/clk/clk-loongson2.c
index bba97270376c..7a916c7d2718 100644
--- a/drivers/clk/clk-loongson2.c
+++ b/drivers/clk/clk-loongson2.c
@@ -361,7 +361,8 @@ static int loongson2_clk_probe(struct platform_device *pdev)
 							  p->parent_name, 0,
 							  clp->base + p->reg_offset,
 							  p->div_shift, p->div_width,
-							  CLK_DIVIDER_ONE_BASED,
+							  CLK_DIVIDER_ONE_BASED |
+							  CLK_DIVIDER_ALLOW_ZERO,
 							  &clp->clk_lock);
 			break;
 		case CLK_TYPE_GATE:
-- 
2.49.0

[PATCH v2 5/8] clk: loongson2: Avoid hardcoding firmware name of the reference clock

[Yao Zi]

Loongson 2K0300 requires a reference clock with a frequency different
from previous SoCs (120MHz v.s. 100MHz), thus hardcoding the firmware
name of the reference clock as ref_100m isn't a good idea.

This patch retrives the clock name of the reference clock dynamically
during probe, avoiding the hardcoded pdata structure and preparing for
support of future SoCs.

Signed-off-by: Yao Zi <ziyao@disroot.org>
---
 drivers/clk/clk-loongson2.c | 33 +++++++++++++++++----------------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/clk/clk-loongson2.c b/drivers/clk/clk-loongson2.c
index 7a916c7d2718..52a9f1c2794a 100644
--- a/drivers/clk/clk-loongson2.c
+++ b/drivers/clk/clk-loongson2.c
@@ -13,10 +13,6 @@
 #include <linux/io-64-nonatomic-lo-hi.h>
 #include <dt-bindings/clock/loongson,ls2k-clk.h>
 
-static const struct clk_parent_data pdata[] = {
-	{ .fw_name = "ref_100m", },
-};
-
 enum loongson2_clk_type {
 	CLK_TYPE_PLL,
 	CLK_TYPE_SCALE,
@@ -275,7 +271,8 @@ static const struct clk_ops loongson2_freqscale_recalc_ops = {
 	.recalc_rate = loongson2_freqscale_recalc_rate,
 };
 
-static struct clk_hw *loongson2_clk_register(struct loongson2_clk_provider *clp,
+static struct clk_hw *loongson2_clk_register(const char *parent,
+					     struct loongson2_clk_provider *clp,
 					     const struct loongson2_clk_board_info *cld,
 					     const struct clk_ops *ops)
 {
@@ -292,11 +289,7 @@ static struct clk_hw *loongson2_clk_register(struct loongson2_clk_provider *clp,
 	init.ops   = ops;
 	init.flags = 0;
 	init.num_parents = 1;
-
-	if (!cld->parent_name)
-		init.parent_data = pdata;
-	else
-		init.parent_names = &cld->parent_name;
+	init.parent_names = &parent;
 
 	clk->reg	= clp->base + cld->reg_offset;
 	clk->div_shift	= cld->div_shift;
@@ -321,11 +314,17 @@ static int loongson2_clk_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct loongson2_clk_provider *clp;
 	const struct loongson2_clk_board_info *p, *data;
+	const char *refclk_name, *parent_name;
 
 	data = device_get_match_data(dev);
 	if (!data)
 		return -EINVAL;
 
+	refclk_name = of_clk_get_parent_name(dev->of_node, 0);
+	if (IS_ERR(refclk_name))
+		return dev_err_probe(dev, PTR_ERR(refclk_name),
+				     "failed to get refclk name\n");
+
 	for (p = data; p->name; p++)
 		clks_num = max(clks_num, p->id + 1);
 
@@ -347,18 +346,20 @@ static int loongson2_clk_probe(struct platform_device *pdev)
 
 	for (i = 0; i < clks_num; i++) {
 		p = &data[i];
+		parent_name = p->parent_name ? p->parent_name : refclk_name;
+
 		switch (p->type) {
 		case CLK_TYPE_PLL:
-			hw = loongson2_clk_register(clp, p,
+			hw = loongson2_clk_register(parent_name, clp, p,
 						    &loongson2_pll_recalc_ops);
 			break;
 		case CLK_TYPE_SCALE:
-			hw = loongson2_clk_register(clp, p,
+			hw = loongson2_clk_register(parent_name, clp, p,
 						    &loongson2_freqscale_recalc_ops);
 			break;
 		case CLK_TYPE_DIVIDER:
 			hw = devm_clk_hw_register_divider(dev, p->name,
-							  p->parent_name, 0,
+							  parent_name, 0,
 							  clp->base + p->reg_offset,
 							  p->div_shift, p->div_width,
 							  CLK_DIVIDER_ONE_BASED |
@@ -366,15 +367,15 @@ static int loongson2_clk_probe(struct platform_device *pdev)
 							  &clp->clk_lock);
 			break;
 		case CLK_TYPE_GATE:
-			hw = devm_clk_hw_register_gate(dev, p->name, p->parent_name,
+			hw = devm_clk_hw_register_gate(dev, p->name, parent_name,
 						       p->flags,
 						       clp->base + p->reg_offset,
 						       p->bit_idx, 0,
 						       &clp->clk_lock);
 			break;
 		case CLK_TYPE_FIXED:
-			hw = devm_clk_hw_register_fixed_rate_parent_data(dev, p->name, pdata,
-									 0, p->fixed_rate);
+			hw = devm_clk_hw_register_fixed_rate(dev, p->name, parent_name,
+							     0, p->fixed_rate);
 			break;
 		default:
 			return dev_err_probe(dev, -EINVAL, "Invalid clk type\n");
-- 
2.49.0

[PATCH v2 6/8] clk: loongson2: Add clock definitions for Loongson 2K0300 SoC

[Yao Zi]

The clock controller of Loongson 2K0300 consists of three PLLs, requires
an 120MHz external reference clock to function, and generates clocks in
various frequencies for SoC peripherals.

Clock definitions for previous SoC generations could be reused for most
clock hardwares. There're two gates marked as critical, clk_node_gate
and clk_boot_gate, which supply the CPU cores and the system
configuration bus. Disabling them leads to a SoC hang.

Signed-off-by: Yao Zi <ziyao@disroot.org>
---
 drivers/clk/clk-loongson2.c | 48 +++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/drivers/clk/clk-loongson2.c b/drivers/clk/clk-loongson2.c
index 52a9f1c2794a..1d210a7683ea 100644
--- a/drivers/clk/clk-loongson2.c
+++ b/drivers/clk/clk-loongson2.c
@@ -12,6 +12,7 @@
 #include <linux/platform_device.h>
 #include <linux/io-64-nonatomic-lo-hi.h>
 #include <dt-bindings/clock/loongson,ls2k-clk.h>
+#include <dt-bindings/clock/loongson,ls2k0300-clk.h>
 
 enum loongson2_clk_type {
 	CLK_TYPE_PLL,
@@ -137,6 +138,52 @@ struct loongson2_clk_board_info {
 		.fixed_rate	= _rate,			\
 	}
 
+static const struct loongson2_clk_board_info ls2k0300_clks[] = {
+	/* Reference Clock */
+	CLK_PLL(LS2K0300_PLL_NODE, "pll_node",   0x00, 15, 9, 8, 7),
+	CLK_PLL(LS2K0300_PLL_DDR,  "pll_ddr",    0x08, 15, 9, 8, 7),
+	CLK_PLL(LS2K0300_PLL_PIX,  "pll_pix",    0x10, 15, 9, 8, 7),
+	CLK_FIXED(LS2K0300_CLK_STABLE, "clk_stable", NULL, 100000000),
+	CLK_FIXED(LS2K0300_CLK_THSENS, "clk_thsens", NULL, 10000000),
+	/* Node PLL */
+	CLK_DIV(LS2K0300_CLK_NODE_DIV, "clk_node_div", "pll_node", 0x00, 24, 7),
+	CLK_DIV(LS2K0300_CLK_GMAC_DIV, "clk_gmac_div", "pll_node", 0x04, 0, 7),
+	CLK_DIV(LS2K0300_CLK_I2S_DIV,  "clk_i2s_div",  "pll_node", 0x04, 8, 7),
+	CLK_GATE(LS2K0300_CLK_NODE_PLL_GATE,   "clk_node_pll_gate", "clk_node_div", 0x00, 0),
+	CLK_GATE(LS2K0300_CLK_GMAC_GATE,       "clk_gmac_gate",	    "clk_gmac_div", 0x00, 1),
+	CLK_GATE(LS2K0300_CLK_I2S_GATE,        "clk_i2s_gate",	    "clk_i2s_div", 0x00, 2),
+	CLK_GATE_FLAGS(LS2K0300_CLK_NODE_GATE, "clk_node_gate",	    "clk_node_scale",
+		       0x24, 0, CLK_IS_CRITICAL),
+	CLK_SCALE_MODE(LS2K0300_CLK_NODE_SCALE,    "clk_node_scale",    "clk_node_pll_gate",
+		       0x20, 0, 3, 3),
+	/* DDR PLL */
+	CLK_DIV(LS2K0300_CLK_DDR_DIV, "clk_ddr_div", "pll_ddr", 0x08, 24, 7),
+	CLK_DIV(LS2K0300_CLK_NET_DIV, "clk_net_div", "pll_ddr", 0x0c, 0, 7),
+	CLK_DIV(LS2K0300_CLK_DEV_DIV, "clk_dev_div", "pll_ddr", 0x0c, 8, 7),
+	CLK_GATE(LS2K0300_CLK_NET_GATE,		"clk_net_gate", "clk_net_div", 0x08, 1),
+	CLK_GATE(LS2K0300_CLK_DEV_GATE,		"clk_dev_gate",	"clk_dev_div", 0x08, 2),
+	CLK_GATE_FLAGS(LS2K0300_CLK_DDR_GATE,	"clk_ddr_gate",	"clk_ddr_div",
+		       0x08, 0, CLK_IS_CRITICAL),
+	/* PIX PLL */
+	CLK_DIV(LS2K0300_CLK_PIX_DIV,	 "clk_pix_div",	   "pll_pix", 0x10, 24, 7),
+	CLK_DIV(LS2K0300_CLK_GMACBP_DIV, "clk_gmacbp_div", "pll_pix", 0x14, 0, 7),
+	CLK_GATE(LS2K0300_CLK_PIX_PLL_GATE, "clk_pix_pll_gate",	"clk_pix_div", 0x10, 0),
+	CLK_GATE(LS2K0300_CLK_PIX_GATE,	    "clk_pix_gate",	"clk_pix_scale", 0x24, 6),
+	CLK_GATE(LS2K0300_CLK_GMACBP_GATE,  "clk_gmacbp_gate",	"clk_gmacbp_div", 0x10, 1),
+	CLK_SCALE_MODE(LS2K0300_CLK_PIX_SCALE,	"clk_pix_scale",	"clk_pix_pll_gate",
+		       0x20, 4, 3, 7),
+	/* clk_dev_gate */
+	CLK_DIV(LS2K0300_CLK_SDIO_SCALE, "clk_sdio_scale", "clk_dev_gate", 0x20, 24, 4),
+	CLK_GATE(LS2K0300_CLK_USB_GATE,	 "clk_usb_gate",	"clk_usb_scale", 0x24, 2),
+	CLK_GATE(LS2K0300_CLK_SDIO_GATE, "clk_sdio_gate",	"clk_sdio_scale", 0x24, 4),
+	CLK_GATE(LS2K0300_CLK_APB_GATE,  "clk_apb_gate",	"clk_apb_scale", 0x24, 3),
+	CLK_GATE_FLAGS(LS2K0300_CLK_BOOT_GATE, "clk_boot_gate",	"clk_boot_scale",
+		       0x24, 1, CLK_IS_CRITICAL),
+	CLK_SCALE_MODE(LS2K0300_CLK_USB_SCALE,  "clk_usb_scale",  "clk_dev_gate", 0x20, 12, 3, 15),
+	CLK_SCALE_MODE(LS2K0300_CLK_APB_SCALE,  "clk_apb_scale",  "clk_dev_gate", 0x20, 16, 3, 19),
+	CLK_SCALE_MODE(LS2K0300_CLK_BOOT_SCALE, "clk_boot_scale", "clk_dev_gate", 0x20, 8, 3, 11),
+};
+
 static const struct loongson2_clk_board_info ls2k0500_clks[] = {
 	CLK_PLL(LOONGSON2_NODE_PLL,   "pll_node", 0,    16, 8, 8, 6),
 	CLK_PLL(LOONGSON2_DDR_PLL,    "pll_ddr",  0x8,  16, 8, 8, 6),
@@ -393,6 +440,7 @@ static int loongson2_clk_probe(struct platform_device *pdev)
 }
 
 static const struct of_device_id loongson2_clk_match_table[] = {
+	{ .compatible = "loongson,ls2k0300-clk", .data = &ls2k0300_clks },
 	{ .compatible = "loongson,ls2k0500-clk", .data = &ls2k0500_clks },
 	{ .compatible = "loongson,ls2k-clk", .data = &ls2k1000_clks },
 	{ .compatible = "loongson,ls2k2000-clk", .data = &ls2k2000_clks },
-- 
2.49.0

[PATCH v2 7/8] LoongArch: dts: Add clock tree for Loongson 2K0300

[Yao Zi]

Describe the clock controller integrated in Loongson 2K0300 SoC and
clocks for UARTs.

Signed-off-by: Yao Zi <ziyao@disroot.org>
---
 arch/loongarch/boot/dts/loongson-2k0300.dtsi | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/arch/loongarch/boot/dts/loongson-2k0300.dtsi b/arch/loongarch/boot/dts/loongson-2k0300.dtsi
index ce3574691aa9..44e37d6f8e98 100644
--- a/arch/loongarch/boot/dts/loongson-2k0300.dtsi
+++ b/arch/loongarch/boot/dts/loongson-2k0300.dtsi
@@ -6,6 +6,7 @@
 
 /dts-v1/;
 
+#include <dt-bindings/clock/loongson,ls2k0300-clk.h>
 #include <dt-bindings/interrupt-controller/irq.h>
 
 / {
@@ -21,7 +22,7 @@ cpu0: cpu@0 {
 			compatible = "loongson,la264";
 			reg = <0>;
 			device_type = "cpu";
-			clocks = <&cpu_clk>;
+			clocks = <&clk LS2K0300_CLK_NODE_GATE>;
 		};
 
 	};
@@ -32,9 +33,10 @@ cpuintc: interrupt-controller {
 		#interrupt-cells = <1>;
 	};
 
-	cpu_clk: clock-1000m {
+	refclk: clock-120m {
 		compatible = "fixed-clock";
-		clock-frequency = <1000000000>;
+		clock-frequency = <120000000>;
+		clock-output-names = "refclk_120m";
 		#clock-cells = <0>;
 	};
 
@@ -46,6 +48,14 @@ soc@10000000 {
 			 <0x00 0x02000000 0x00 0x02000000 0x0 0x04000000>,
 			 <0x00 0x40000000 0x00 0x40000000 0x0 0x40000000>;
 
+		clk: clock-controller@16000400 {
+			compatible = "loongson,ls2k0300-clk";
+			reg = <0x0 0x16000400 0x0 0x100>;
+			clocks = <&refclk>;
+			clock-names = "ref_120m";
+			#clock-cells = <1>;
+		};
+
 		liointc0: interrupt-controller@16001400 {
 			compatible = "loongson,liointc-2.0";
 			reg = <0x0 0x16001400 0x0 0x40>,
@@ -87,6 +97,7 @@ liointc1: interrupt-controller@16001440 {
 		uart0: serial@16100000 {
 			compatible = "ns16550a";
 			reg = <0 0x16100000 0 0x10>;
+			clocks = <&clk LS2K0300_CLK_APB_GATE>;
 			interrupt-parent = <&liointc0>;
 			interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
 			no-loopback-test;
-- 
2.49.0

[PATCH v2 8/8] LoongArch: dts: Remove clock-frquency from UART0 of CTCISZ Forever Pi

[Yao Zi]

The property isn't required anymore as the supply clock of UART0 has
been described.

Signed-off-by: Yao Zi <ziyao@disroot.org>
---
 arch/loongarch/boot/dts/loongson-2k0300-ctcisz-forever-pi.dts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/loongarch/boot/dts/loongson-2k0300-ctcisz-forever-pi.dts b/arch/loongarch/boot/dts/loongson-2k0300-ctcisz-forever-pi.dts
index a033c086461f..1bdfff7fae92 100644
--- a/arch/loongarch/boot/dts/loongson-2k0300-ctcisz-forever-pi.dts
+++ b/arch/loongarch/boot/dts/loongson-2k0300-ctcisz-forever-pi.dts
@@ -40,6 +40,5 @@ linux,cma {
 };
 
 &uart0 {
-	clock-frequency = <100000000>;
 	status = "okay";
 };
-- 
2.49.0

Re: [PATCH v2 0/8] Add clock support for Loongson 2K0300 SoC

[Huacai Chen]

Hi, Yao,

I suggest dropping the last two patches temporarily, because:
1, the last two should be merged via another tree.
2, the last two depend on another series which hasn't been merged now,
and can be squashed to that series.

Huacai

On Wed, Jun 18, 2025 at 12:25 AM Yao Zi <ziyao@disroot.org> wrote:
>
> This series adds support for Loongson 2K0300's clock controller.
> Loongson 2 clock driver is prepared to support more clock variants and
> its flexibility is improved. All clock hardwares except the output one
> for GMAC module are then defined.
>
> A clock tree dump could be obtained here[1]. This series depends on v3
> of series "Initial support for CTCISZ Forever Pi"[2] to apply.
>
> [1]: https://gist.github.com/ziyao233/160bb4693e7758b2a2a996d4510b7247
> [2]: https://lore.kernel.org/all/20250523095408.25919-1-ziyao@disroot.org/
>
> Changed from v1:
> - Fold loongson,ls2k0300-clk.yaml into loongson,ls2k-clk.yaml
> - Include the new binding header in MAINTAINERS
> - Link to v1: https://lore.kernel.org/all/20250523104552.32742-1-ziyao@disroot.org/
>
> Yao Zi (8):
>   dt-bindings: clock: loongson2: Add Loongson 2K0300 compatible
>   clk: loongson2: Allow specifying clock flags for gate clock
>   clk: loongson2: Support scale clocks with an alternative mode
>   clk: loongson2: Allow zero divisors for dividers
>   clk: loongson2: Avoid hardcoding firmware name of the reference clock
>   clk: loongson2: Add clock definitions for Loongson 2K0300 SoC
>   LoongArch: dts: Add clock tree for Loongson 2K0300
>   LoongArch: dts: Remove clock-frquency from UART0 of CTCISZ Forever Pi
>
>  .../bindings/clock/loongson,ls2k-clk.yaml     |  26 +++-
>  MAINTAINERS                                   |   1 +
>  .../dts/loongson-2k0300-ctcisz-forever-pi.dts |   1 -
>  arch/loongarch/boot/dts/loongson-2k0300.dtsi  |  17 ++-
>  drivers/clk/clk-loongson2.c                   | 124 +++++++++++++++---
>  .../dt-bindings/clock/loongson,ls2k0300-clk.h |  54 ++++++++
>  6 files changed, 193 insertions(+), 30 deletions(-)
>  create mode 100644 include/dt-bindings/clock/loongson,ls2k0300-clk.h
>
> --
> 2.49.0
>
>

Re: [PATCH v2 0/8] Add clock support for Loongson 2K0300 SoC

[Yao Zi]

On Thu, Jun 19, 2025 at 05:02:48PM +0800, Huacai Chen wrote:
> Hi, Yao,
> 
> I suggest dropping the last two patches temporarily, because:
> 1, the last two should be merged via another tree.
> 2, the last two depend on another series which hasn't been merged now,
> and can be squashed to that series.

These are fair points, but I think including corresponding devicetree
changes along with the binding patch helps review and proves the binding
makes sense. it should be okay to merge only parts of a series, so I
guess keeping the patches doesn't hurt, does it?

By the way, do you prefer to wait until all fundamental drivers (clock,
pinctrl, and reset) ready and merged, then merge the devicetree with all
the three devices added? Or is it just fine to go part by part, with
incremental changes to the devicetree?

Best regards,
Yao Zi

> Huacai
> 
> On Wed, Jun 18, 2025 at 12:25 AM Yao Zi <ziyao@disroot.org> wrote:
> >
> > This series adds support for Loongson 2K0300's clock controller.
> > Loongson 2 clock driver is prepared to support more clock variants and
> > its flexibility is improved. All clock hardwares except the output one
> > for GMAC module are then defined.
> >
> > A clock tree dump could be obtained here[1]. This series depends on v3
> > of series "Initial support for CTCISZ Forever Pi"[2] to apply.
> >
> > [1]: https://gist.github.com/ziyao233/160bb4693e7758b2a2a996d4510b7247
> > [2]: https://lore.kernel.org/all/20250523095408.25919-1-ziyao@disroot.org/
> >
> > Changed from v1:
> > - Fold loongson,ls2k0300-clk.yaml into loongson,ls2k-clk.yaml
> > - Include the new binding header in MAINTAINERS
> > - Link to v1: https://lore.kernel.org/all/20250523104552.32742-1-ziyao@disroot.org/
> >
> > Yao Zi (8):
> >   dt-bindings: clock: loongson2: Add Loongson 2K0300 compatible
> >   clk: loongson2: Allow specifying clock flags for gate clock
> >   clk: loongson2: Support scale clocks with an alternative mode
> >   clk: loongson2: Allow zero divisors for dividers
> >   clk: loongson2: Avoid hardcoding firmware name of the reference clock
> >   clk: loongson2: Add clock definitions for Loongson 2K0300 SoC
> >   LoongArch: dts: Add clock tree for Loongson 2K0300
> >   LoongArch: dts: Remove clock-frquency from UART0 of CTCISZ Forever Pi
> >
> >  .../bindings/clock/loongson,ls2k-clk.yaml     |  26 +++-
> >  MAINTAINERS                                   |   1 +
> >  .../dts/loongson-2k0300-ctcisz-forever-pi.dts |   1 -
> >  arch/loongarch/boot/dts/loongson-2k0300.dtsi  |  17 ++-
> >  drivers/clk/clk-loongson2.c                   | 124 +++++++++++++++---
> >  .../dt-bindings/clock/loongson,ls2k0300-clk.h |  54 ++++++++
> >  6 files changed, 193 insertions(+), 30 deletions(-)
> >  create mode 100644 include/dt-bindings/clock/loongson,ls2k0300-clk.h
> >
> > --
> > 2.49.0
> >
> >

Re: [PATCH v2 0/8] Add clock support for Loongson 2K0300 SoC

[Huacai Chen]

On Thu, Jun 19, 2025 at 9:17 PM Yao Zi <ziyao@disroot.org> wrote:
>
> On Thu, Jun 19, 2025 at 05:02:48PM +0800, Huacai Chen wrote:
> > Hi, Yao,
> >
> > I suggest dropping the last two patches temporarily, because:
> > 1, the last two should be merged via another tree.
> > 2, the last two depend on another series which hasn't been merged now,
> > and can be squashed to that series.
>
> These are fair points, but I think including corresponding devicetree
> changes along with the binding patch helps review and proves the binding
> makes sense. it should be okay to merge only parts of a series, so I
> guess keeping the patches doesn't hurt, does it?
Yes, keeping them is just OK.

>
> By the way, do you prefer to wait until all fundamental drivers (clock,
> pinctrl, and reset) ready and merged, then merge the devicetree with all
> the three devices added? Or is it just fine to go part by part, with
> incremental changes to the devicetree?
Yes, I prefer to wait until fundamental drivers are merged.


Huacai

>
> Best regards,
> Yao Zi
>
> > Huacai
> >
> > On Wed, Jun 18, 2025 at 12:25 AM Yao Zi <ziyao@disroot.org> wrote:
> > >
> > > This series adds support for Loongson 2K0300's clock controller.
> > > Loongson 2 clock driver is prepared to support more clock variants and
> > > its flexibility is improved. All clock hardwares except the output one
> > > for GMAC module are then defined.
> > >
> > > A clock tree dump could be obtained here[1]. This series depends on v3
> > > of series "Initial support for CTCISZ Forever Pi"[2] to apply.
> > >
> > > [1]: https://gist.github.com/ziyao233/160bb4693e7758b2a2a996d4510b7247
> > > [2]: https://lore.kernel.org/all/20250523095408.25919-1-ziyao@disroot.org/
> > >
> > > Changed from v1:
> > > - Fold loongson,ls2k0300-clk.yaml into loongson,ls2k-clk.yaml
> > > - Include the new binding header in MAINTAINERS
> > > - Link to v1: https://lore.kernel.org/all/20250523104552.32742-1-ziyao@disroot.org/
> > >
> > > Yao Zi (8):
> > >   dt-bindings: clock: loongson2: Add Loongson 2K0300 compatible
> > >   clk: loongson2: Allow specifying clock flags for gate clock
> > >   clk: loongson2: Support scale clocks with an alternative mode
> > >   clk: loongson2: Allow zero divisors for dividers
> > >   clk: loongson2: Avoid hardcoding firmware name of the reference clock
> > >   clk: loongson2: Add clock definitions for Loongson 2K0300 SoC
> > >   LoongArch: dts: Add clock tree for Loongson 2K0300
> > >   LoongArch: dts: Remove clock-frquency from UART0 of CTCISZ Forever Pi
> > >
> > >  .../bindings/clock/loongson,ls2k-clk.yaml     |  26 +++-
> > >  MAINTAINERS                                   |   1 +
> > >  .../dts/loongson-2k0300-ctcisz-forever-pi.dts |   1 -
> > >  arch/loongarch/boot/dts/loongson-2k0300.dtsi  |  17 ++-
> > >  drivers/clk/clk-loongson2.c                   | 124 +++++++++++++++---
> > >  .../dt-bindings/clock/loongson,ls2k0300-clk.h |  54 ++++++++
> > >  6 files changed, 193 insertions(+), 30 deletions(-)
> > >  create mode 100644 include/dt-bindings/clock/loongson,ls2k0300-clk.h
> > >
> > > --
> > > 2.49.0
> > >
> > >
>