[PATCH v2] dt-bindings: i2c: ls2x-i2c: Add clocks and clock-frequency properties

[PATCH v2] dt-bindings: i2c: ls2x-i2c: Add clocks and clock-frequency properties

[Hongliang Wang]

From: wanghongliang <wanghongliang@loongson.cn>

clocks property describes the i2c bus reference clock from APB clock.
clock-frequency property describes i2c bus speed.

Signed-off-by: wanghongliang <wanghongliang@loongson.cn>
---
 Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml b/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml
index ee09c6d9c5f0..4bf89bb97e7d 100644
--- a/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml
@@ -38,10 +38,13 @@ unevaluatedProperties: false
 examples:
   - |
     #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/clock/loongson,ls2k-clk.h>
 
     i2c0: i2c@1fe21000 {
         compatible = "loongson,ls2k-i2c";
         reg = <0x1fe21000 0x8>;
+        clock-frequency = <100000>;
+        clocks = <&clk LOONGSON2_APB_CLK>;
         interrupt-parent = <&extioiic>;
         interrupts = <22 IRQ_TYPE_LEVEL_LOW>;
         #address-cells = <1>;
-- 
2.47.2

[PATCH v2] i2c: ls2x: Add clocks property parsing and adjust bus speed

[Hongliang Wang]

From: wanghongliang <wanghongliang@loongson.cn>

The i2c-ls2x driver supports dts and acpi parameter passing.
In dts, uses clock framework, by parsing clocks property to
get i2c bus reference clock, and define factor by device data.
In acpi, by passing clocks property to describe i2c bus reference
clock and clock-div property to describe factor.
Based on i2c bus reference clock(clock_a), i2c bus speed(clock_s)
and factor, calculate the prcescale of i2c divider register.
The calculation formula is
prcescale = clock_a/(factor*clock_s)-1

Signed-off-by: wanghongliang <wanghongliang@loongson.cn>
---
 drivers/i2c/busses/i2c-ls2x.c | 42 ++++++++++++++++++++++++++++++++---
 1 file changed, 39 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-ls2x.c b/drivers/i2c/busses/i2c-ls2x.c
index b475dd27b7af..7db91e7a5d78 100644
--- a/drivers/i2c/busses/i2c-ls2x.c
+++ b/drivers/i2c/busses/i2c-ls2x.c
@@ -13,6 +13,7 @@
 #include <linux/bitfield.h>
 #include <linux/bits.h>
 #include <linux/completion.h>
+#include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/iopoll.h>
 #include <linux/i2c.h>
@@ -63,11 +64,16 @@
 /* The default bus frequency, which is an empirical value */
 #define LS2X_I2C_FREQ_STD	(33 * HZ_PER_KHZ)
 
+struct ls2x_i2c_chip_data {
+	unsigned int	factor;
+};
+
 struct ls2x_i2c_priv {
 	struct i2c_adapter	adapter;
 	void __iomem		*base;
 	struct i2c_timings	i2c_t;
 	struct completion	cmd_complete;
+	const struct ls2x_i2c_chip_data	*chip_data;
 };
 
 /*
@@ -96,6 +102,8 @@ static irqreturn_t ls2x_i2c_isr(int this_irq, void *dev_id)
 static void ls2x_i2c_adjust_bus_speed(struct ls2x_i2c_priv *priv)
 {
 	u16 val;
+	u32 pclk, factor;
+	struct clk *clk;
 	struct i2c_timings *t = &priv->i2c_t;
 	struct device *dev = priv->adapter.dev.parent;
 	u32 acpi_speed = i2c_acpi_find_bus_speed(dev);
@@ -107,12 +115,30 @@ static void ls2x_i2c_adjust_bus_speed(struct ls2x_i2c_priv *priv)
 	else
 		t->bus_freq_hz = LS2X_I2C_FREQ_STD;
 
+	if (dev_of_node(dev)) {
+		clk = devm_clk_get_optional_enabled(dev, NULL);
+		if (IS_ERR(clk) || !clk)
+			pclk = LS2X_I2C_PCLK_FREQ;
+		else
+			pclk = clk_get_rate(clk);
+
+		factor = priv->chip_data->factor;
+
+		val = (pclk * 10) / (factor * t->bus_freq_hz) - 1;
+	} else {
+		if (!device_property_read_u32(dev, "clocks", &pclk) &&
+		    !device_property_read_u32(dev, "clock-div", &factor) &&
+		    factor != 0)
+			val = (pclk * 10) / (factor * t->bus_freq_hz) - 1;
+		else
+			val = LS2X_I2C_PCLK_FREQ / (5 * t->bus_freq_hz) - 1;
+	}
+
 	/*
 	 * According to the chip manual, we can only access the registers as bytes,
 	 * otherwise the high bits will be truncated.
 	 * So set the I2C frequency with a sequential writeb() instead of writew().
 	 */
-	val = LS2X_I2C_PCLK_FREQ / (5 * t->bus_freq_hz) - 1;
 	writeb(FIELD_GET(GENMASK(7, 0), val), priv->base + I2C_LS2X_PRER_LO);
 	writeb(FIELD_GET(GENMASK(15, 8), val), priv->base + I2C_LS2X_PRER_HI);
 }
@@ -295,6 +321,8 @@ static int ls2x_i2c_probe(struct platform_device *pdev)
 	if (!priv)
 		return -ENOMEM;
 
+	priv->chip_data = device_get_match_data(dev);
+
 	/* Map hardware registers */
 	priv->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(priv->base))
@@ -348,9 +376,17 @@ static int ls2x_i2c_resume(struct device *dev)
 static DEFINE_RUNTIME_DEV_PM_OPS(ls2x_i2c_pm_ops,
 				 ls2x_i2c_suspend, ls2x_i2c_resume, NULL);
 
+static const struct ls2x_i2c_chip_data ls2x_i2c_2k_data = {
+	.factor = 4,
+};
+
+static const struct ls2x_i2c_chip_data ls2x_i2c_7a_data = {
+	.factor = 5,
+};
+
 static const struct of_device_id ls2x_i2c_id_table[] = {
-	{ .compatible = "loongson,ls2k-i2c" },
-	{ .compatible = "loongson,ls7a-i2c" },
+	{ .compatible = "loongson,ls2k-i2c", .data = &ls2x_i2c_2k_data, },
+	{ .compatible = "loongson,ls7a-i2c", .data = &ls2x_i2c_7a_data, },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, ls2x_i2c_id_table);
-- 
2.47.2

Re: [PATCH v2] dt-bindings: i2c: ls2x-i2c: Add clocks and clock-frequency properties

[Conor Dooley]

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On Thu, May 07, 2026 at 04:10:09PM +0800, Hongliang Wang wrote:
> From: wanghongliang <wanghongliang@loongson.cn>
> 
> clocks property describes the i2c bus reference clock from APB clock.
> clock-frequency property describes i2c bus speed.
> 
> Signed-off-by: wanghongliang <wanghongliang@loongson.cn>
> ---
>  Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml b/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml
> index ee09c6d9c5f0..4bf89bb97e7d 100644
> --- a/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml
> +++ b/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml
> @@ -38,10 +38,13 @@ unevaluatedProperties: false
>  examples:
>    - |
>      #include <dt-bindings/interrupt-controller/irq.h>
> +    #include <dt-bindings/clock/loongson,ls2k-clk.h>
>  
>      i2c0: i2c@1fe21000 {
>          compatible = "loongson,ls2k-i2c";
>          reg = <0x1fe21000 0x8>;
> +        clock-frequency = <100000>;
> +        clocks = <&clk LOONGSON2_APB_CLK>;

/stuff/linux-dt/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.example.dtb: i2c@1fe21000 (loongson,ls2k-i2c): Unevaluated properties are not allowed ('clocks' was unexpected)
	from schema $id: http://devicetree.org/schemas/i2c/loongson,ls2x-i2c.yaml


Please test your patches before sending them.

Does this device actually have a clock or not?

Cheers,
Conor.

>          interrupt-parent = <&extioiic>;
>          interrupts = <22 IRQ_TYPE_LEVEL_LOW>;
>          #address-cells = <1>;
> -- 
> 2.47.2
> 

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Re: [PATCH v2] dt-bindings: i2c: ls2x-i2c: Add clocks and clock-frequency properties

[Hongliang Wang]

On 2026/5/8 上午1:29, Conor Dooley wrote:
> On Thu, May 07, 2026 at 04:10:09PM +0800, Hongliang Wang wrote:
>> From: wanghongliang <wanghongliang@loongson.cn>
>>
>> clocks property describes the i2c bus reference clock from APB clock.
>> clock-frequency property describes i2c bus speed.
>>
>> Signed-off-by: wanghongliang <wanghongliang@loongson.cn>
>> ---
>>   Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml b/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml
>> index ee09c6d9c5f0..4bf89bb97e7d 100644
>> --- a/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml
>> +++ b/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml
>> @@ -38,10 +38,13 @@ unevaluatedProperties: false
>>   examples:
>>     - |
>>       #include <dt-bindings/interrupt-controller/irq.h>
>> +    #include <dt-bindings/clock/loongson,ls2k-clk.h>
>>   
>>       i2c0: i2c@1fe21000 {
>>           compatible = "loongson,ls2k-i2c";
>>           reg = <0x1fe21000 0x8>;
>> +        clock-frequency = <100000>;
>> +        clocks = <&clk LOONGSON2_APB_CLK>;
> /stuff/linux-dt/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.example.dtb: i2c@1fe21000 (loongson,ls2k-i2c): Unevaluated properties are not allowed ('clocks' was unexpected)
> 	from schema $id: http://devicetree.org/schemas/i2c/loongson,ls2x-i2c.yaml
>
>
> Please test your patches before sending them.
The error is becasue there is no clocks property in loongson,ls2x-i2c.yaml.
The patch is based on the following repository and uses the 
i2c-host-next branch.
I found the clocks property already exist in loongson,ls2x-i2c.yaml, so 
I didn't
add it in my patch

git://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux.git
>
> Does this device actually have a clock or not?
Yes,  the clock actually exists.
>
> Cheers,
> Conor.
>
>>           interrupt-parent = <&extioiic>;
>>           interrupts = <22 IRQ_TYPE_LEVEL_LOW>;
>>           #address-cells = <1>;
>> -- 
>> 2.47.2
>>
Best regards,
Hongliang Wang

Re: [PATCH v2] i2c: ls2x: Add clocks property parsing and adjust bus speed

[Huacai Chen]

Hi, Hongliang,

On Thu, May 7, 2026 at 4:11 PM Hongliang Wang <wanghongliang@loongson.cn> wrote:
>
> From: wanghongliang <wanghongliang@loongson.cn>
>
> The i2c-ls2x driver supports dts and acpi parameter passing.
> In dts, uses clock framework, by parsing clocks property to
> get i2c bus reference clock, and define factor by device data.
> In acpi, by passing clocks property to describe i2c bus reference
> clock and clock-div property to describe factor.
> Based on i2c bus reference clock(clock_a), i2c bus speed(clock_s)
> and factor, calculate the prcescale of i2c divider register.
> The calculation formula is
> prcescale = clock_a/(factor*clock_s)-1
>
> Signed-off-by: wanghongliang <wanghongliang@loongson.cn>
> ---
>  drivers/i2c/busses/i2c-ls2x.c | 42 ++++++++++++++++++++++++++++++++---
>  1 file changed, 39 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-ls2x.c b/drivers/i2c/busses/i2c-ls2x.c
> index b475dd27b7af..7db91e7a5d78 100644
> --- a/drivers/i2c/busses/i2c-ls2x.c
> +++ b/drivers/i2c/busses/i2c-ls2x.c
> @@ -13,6 +13,7 @@
>  #include <linux/bitfield.h>
>  #include <linux/bits.h>
>  #include <linux/completion.h>
> +#include <linux/clk.h>
This should be before completion.h.

>  #include <linux/device.h>
>  #include <linux/iopoll.h>
>  #include <linux/i2c.h>
> @@ -63,11 +64,16 @@
>  /* The default bus frequency, which is an empirical value */
>  #define LS2X_I2C_FREQ_STD      (33 * HZ_PER_KHZ)
>
> +struct ls2x_i2c_chip_data {
> +       unsigned int    factor;
> +};
> +
>  struct ls2x_i2c_priv {
>         struct i2c_adapter      adapter;
>         void __iomem            *base;
>         struct i2c_timings      i2c_t;
>         struct completion       cmd_complete;
> +       const struct ls2x_i2c_chip_data *chip_data;
Use "unsigned int    factor" directly?

>  };
>
>  /*
> @@ -96,6 +102,8 @@ static irqreturn_t ls2x_i2c_isr(int this_irq, void *dev_id)
>  static void ls2x_i2c_adjust_bus_speed(struct ls2x_i2c_priv *priv)
>  {
>         u16 val;
> +       u32 pclk, factor;
factor or div? If factor is better, then rename clock-div to
clock-factor; if div is better, then rename factor to div.

> +       struct clk *clk;
>         struct i2c_timings *t = &priv->i2c_t;
>         struct device *dev = priv->adapter.dev.parent;
>         u32 acpi_speed = i2c_acpi_find_bus_speed(dev);
> @@ -107,12 +115,30 @@ static void ls2x_i2c_adjust_bus_speed(struct ls2x_i2c_priv *priv)
>         else
>                 t->bus_freq_hz = LS2X_I2C_FREQ_STD;
>
> +       if (dev_of_node(dev)) {
> +               clk = devm_clk_get_optional_enabled(dev, NULL);
> +               if (IS_ERR(clk) || !clk)
> +                       pclk = LS2X_I2C_PCLK_FREQ;
> +               else
> +                       pclk = clk_get_rate(clk);
Reverse the "if & else" so the default case will be the last one, this
is also the same as the ACPI case below.

Huacai

> +
> +               factor = priv->chip_data->factor;
> +
> +               val = (pclk * 10) / (factor * t->bus_freq_hz) - 1;
> +       } else {
> +               if (!device_property_read_u32(dev, "clocks", &pclk) &&
> +                   !device_property_read_u32(dev, "clock-div", &factor) &&
> +                   factor != 0)
> +                       val = (pclk * 10) / (factor * t->bus_freq_hz) - 1;
> +               else
> +                       val = LS2X_I2C_PCLK_FREQ / (5 * t->bus_freq_hz) - 1;
> +       }
> +
>         /*
>          * According to the chip manual, we can only access the registers as bytes,
>          * otherwise the high bits will be truncated.
>          * So set the I2C frequency with a sequential writeb() instead of writew().
>          */
> -       val = LS2X_I2C_PCLK_FREQ / (5 * t->bus_freq_hz) - 1;
>         writeb(FIELD_GET(GENMASK(7, 0), val), priv->base + I2C_LS2X_PRER_LO);
>         writeb(FIELD_GET(GENMASK(15, 8), val), priv->base + I2C_LS2X_PRER_HI);
>  }
> @@ -295,6 +321,8 @@ static int ls2x_i2c_probe(struct platform_device *pdev)
>         if (!priv)
>                 return -ENOMEM;
>
> +       priv->chip_data = device_get_match_data(dev);
> +
>         /* Map hardware registers */
>         priv->base = devm_platform_ioremap_resource(pdev, 0);
>         if (IS_ERR(priv->base))
> @@ -348,9 +376,17 @@ static int ls2x_i2c_resume(struct device *dev)
>  static DEFINE_RUNTIME_DEV_PM_OPS(ls2x_i2c_pm_ops,
>                                  ls2x_i2c_suspend, ls2x_i2c_resume, NULL);
>
> +static const struct ls2x_i2c_chip_data ls2x_i2c_2k_data = {
> +       .factor = 4,
> +};
> +
> +static const struct ls2x_i2c_chip_data ls2x_i2c_7a_data = {
> +       .factor = 5,
> +};
> +
>  static const struct of_device_id ls2x_i2c_id_table[] = {
> -       { .compatible = "loongson,ls2k-i2c" },
> -       { .compatible = "loongson,ls7a-i2c" },
> +       { .compatible = "loongson,ls2k-i2c", .data = &ls2x_i2c_2k_data, },
> +       { .compatible = "loongson,ls7a-i2c", .data = &ls2x_i2c_7a_data, },
>         { /* sentinel */ }
>  };
>  MODULE_DEVICE_TABLE(of, ls2x_i2c_id_table);
> --
> 2.47.2
>
>

Re: [PATCH v2] dt-bindings: i2c: ls2x-i2c: Add clocks and clock-frequency properties

[Conor Dooley]

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On Fri, May 08, 2026 at 09:29:08AM +0800, Hongliang Wang wrote:
> 
> On 2026/5/8 上午1:29, Conor Dooley wrote:
> > On Thu, May 07, 2026 at 04:10:09PM +0800, Hongliang Wang wrote:
> > > From: wanghongliang <wanghongliang@loongson.cn>
> > > 
> > > clocks property describes the i2c bus reference clock from APB clock.
> > > clock-frequency property describes i2c bus speed.
> > > 
> > > Signed-off-by: wanghongliang <wanghongliang@loongson.cn>
> > > ---
> > >   Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml | 3 +++
> > >   1 file changed, 3 insertions(+)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml b/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml
> > > index ee09c6d9c5f0..4bf89bb97e7d 100644
> > > --- a/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml
> > > +++ b/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml
> > > @@ -38,10 +38,13 @@ unevaluatedProperties: false
> > >   examples:
> > >     - |
> > >       #include <dt-bindings/interrupt-controller/irq.h>
> > > +    #include <dt-bindings/clock/loongson,ls2k-clk.h>
> > >       i2c0: i2c@1fe21000 {
> > >           compatible = "loongson,ls2k-i2c";
> > >           reg = <0x1fe21000 0x8>;
> > > +        clock-frequency = <100000>;
> > > +        clocks = <&clk LOONGSON2_APB_CLK>;
> > /stuff/linux-dt/Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.example.dtb: i2c@1fe21000 (loongson,ls2k-i2c): Unevaluated properties are not allowed ('clocks' was unexpected)
> > 	from schema $id: http://devicetree.org/schemas/i2c/loongson,ls2x-i2c.yaml
> > 
> > 
> > Please test your patches before sending them.
> The error is becasue there is no clocks property in loongson,ls2x-i2c.yaml.
> The patch is based on the following repository and uses the i2c-host-next
> branch.
> I found the clocks property already exist in loongson,ls2x-i2c.yaml, so I
> didn't
> add it in my patch
> 
> git://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux.git

Ah, my bad then.

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

> > 
> > Does this device actually have a clock or not?
> Yes,  the clock actually exists.
> > 
> > Cheers,
> > Conor.
> > 
> > >           interrupt-parent = <&extioiic>;
> > >           interrupts = <22 IRQ_TYPE_LEVEL_LOW>;
> > >           #address-cells = <1>;
> > > -- 
> > > 2.47.2
> > > 
> Best regards,
> Hongliang Wang
> 
> 

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Re: [PATCH v2] i2c: ls2x: Add clocks property parsing and adjust bus speed

[Hongliang Wang]

Hi, Huacai,

On 2026/5/8 上午11:06, Huacai Chen wrote:
> Hi, Hongliang,
>
> On Thu, May 7, 2026 at 4:11 PM Hongliang Wang <wanghongliang@loongson.cn> wrote:
>> From: wanghongliang <wanghongliang@loongson.cn>
>>
>> The i2c-ls2x driver supports dts and acpi parameter passing.
>> In dts, uses clock framework, by parsing clocks property to
>> get i2c bus reference clock, and define factor by device data.
>> In acpi, by passing clocks property to describe i2c bus reference
>> clock and clock-div property to describe factor.
>> Based on i2c bus reference clock(clock_a), i2c bus speed(clock_s)
>> and factor, calculate the prcescale of i2c divider register.
>> The calculation formula is
>> prcescale = clock_a/(factor*clock_s)-1
>>
>> Signed-off-by: wanghongliang <wanghongliang@loongson.cn>
>> ---
>>   drivers/i2c/busses/i2c-ls2x.c | 42 ++++++++++++++++++++++++++++++++---
>>   1 file changed, 39 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-ls2x.c b/drivers/i2c/busses/i2c-ls2x.c
>> index b475dd27b7af..7db91e7a5d78 100644
>> --- a/drivers/i2c/busses/i2c-ls2x.c
>> +++ b/drivers/i2c/busses/i2c-ls2x.c
>> @@ -13,6 +13,7 @@
>>   #include <linux/bitfield.h>
>>   #include <linux/bits.h>
>>   #include <linux/completion.h>
>> +#include <linux/clk.h>
> This should be before completion.h.
>
OK.
>>   #include <linux/device.h>
>>   #include <linux/iopoll.h>
>>   #include <linux/i2c.h>
>> @@ -63,11 +64,16 @@
>>   /* The default bus frequency, which is an empirical value */
>>   #define LS2X_I2C_FREQ_STD      (33 * HZ_PER_KHZ)
>>
>> +struct ls2x_i2c_chip_data {
>> +       unsigned int    factor;
>> +};
>> +
>>   struct ls2x_i2c_priv {
>>          struct i2c_adapter      adapter;
>>          void __iomem            *base;
>>          struct i2c_timings      i2c_t;
>>          struct completion       cmd_complete;
>> +       const struct ls2x_i2c_chip_data *chip_data;
> Use "unsigned int    factor" directly?
>
OK,  I will adjust it
>>   };
>>
>>   /*
>> @@ -96,6 +102,8 @@ static irqreturn_t ls2x_i2c_isr(int this_irq, void *dev_id)
>>   static void ls2x_i2c_adjust_bus_speed(struct ls2x_i2c_priv *priv)
>>   {
>>          u16 val;
>> +       u32 pclk, factor;
> factor or div? If factor is better, then rename clock-div to
> clock-factor; if div is better, then rename factor to div.
div is better,  I will adjust it
>> +       struct clk *clk;
>>          struct i2c_timings *t = &priv->i2c_t;
>>          struct device *dev = priv->adapter.dev.parent;
>>          u32 acpi_speed = i2c_acpi_find_bus_speed(dev);
>> @@ -107,12 +115,30 @@ static void ls2x_i2c_adjust_bus_speed(struct ls2x_i2c_priv *priv)
>>          else
>>                  t->bus_freq_hz = LS2X_I2C_FREQ_STD;
>>
>> +       if (dev_of_node(dev)) {
>> +               clk = devm_clk_get_optional_enabled(dev, NULL);
>> +               if (IS_ERR(clk) || !clk)
>> +                       pclk = LS2X_I2C_PCLK_FREQ;
>> +               else
>> +                       pclk = clk_get_rate(clk);
> Reverse the "if & else" so the default case will be the last one, this
> is also the same as the ACPI case below.
OK
> Huacai
>
>> +
>> +               factor = priv->chip_data->factor;
>> +
>> +               val = (pclk * 10) / (factor * t->bus_freq_hz) - 1;
>> +       } else {
>> +               if (!device_property_read_u32(dev, "clocks", &pclk) &&
>> +                   !device_property_read_u32(dev, "clock-div", &factor) &&
>> +                   factor != 0)
>> +                       val = (pclk * 10) / (factor * t->bus_freq_hz) - 1;
>> +               else
>> +                       val = LS2X_I2C_PCLK_FREQ / (5 * t->bus_freq_hz) - 1;
>> +       }
>> +
>>          /*
>>           * According to the chip manual, we can only access the registers as bytes,
>>           * otherwise the high bits will be truncated.
>>           * So set the I2C frequency with a sequential writeb() instead of writew().
>>           */
>> -       val = LS2X_I2C_PCLK_FREQ / (5 * t->bus_freq_hz) - 1;
>>          writeb(FIELD_GET(GENMASK(7, 0), val), priv->base + I2C_LS2X_PRER_LO);
>>          writeb(FIELD_GET(GENMASK(15, 8), val), priv->base + I2C_LS2X_PRER_HI);
>>   }
>> @@ -295,6 +321,8 @@ static int ls2x_i2c_probe(struct platform_device *pdev)
>>          if (!priv)
>>                  return -ENOMEM;
>>
>> +       priv->chip_data = device_get_match_data(dev);
>> +
>>          /* Map hardware registers */
>>          priv->base = devm_platform_ioremap_resource(pdev, 0);
>>          if (IS_ERR(priv->base))
>> @@ -348,9 +376,17 @@ static int ls2x_i2c_resume(struct device *dev)
>>   static DEFINE_RUNTIME_DEV_PM_OPS(ls2x_i2c_pm_ops,
>>                                   ls2x_i2c_suspend, ls2x_i2c_resume, NULL);
>>
>> +static const struct ls2x_i2c_chip_data ls2x_i2c_2k_data = {
>> +       .factor = 4,
>> +};
>> +
>> +static const struct ls2x_i2c_chip_data ls2x_i2c_7a_data = {
>> +       .factor = 5,
>> +};
>> +
>>   static const struct of_device_id ls2x_i2c_id_table[] = {
>> -       { .compatible = "loongson,ls2k-i2c" },
>> -       { .compatible = "loongson,ls7a-i2c" },
>> +       { .compatible = "loongson,ls2k-i2c", .data = &ls2x_i2c_2k_data, },
>> +       { .compatible = "loongson,ls7a-i2c", .data = &ls2x_i2c_7a_data, },
>>          { /* sentinel */ }
>>   };
>>   MODULE_DEVICE_TABLE(of, ls2x_i2c_id_table);
>> --
>> 2.47.2
>>
>>
Best regards,
Hongliang Wang