[PATCH v4 0/3] riscv: pwm: sophgo: add pwm support for SG2044

[PATCH v4 0/3] riscv: pwm: sophgo: add pwm support for SG2044

[Longbin Li]

This patch adds PWM controller support for four independent
PWM channel outputs.

---

Changes in v4:

  - add tags for mail.

Changes in v3:
  You can simply review or test the patches at the link [3].

  - Rename macro definitions to unify naming.
  - Modify code style.

Changes in v2:
  You can simply review or test the patches at the link [2].

  - Modify variable naming and code logic.
  - update "MODULE_AUTHOR".

Changes in v1:
  You can simply review or test the patches at the link [1].

Link: https://lore.kernel.org/linux-riscv/20250407072056.8629-1-looong.bin@gmail.com/ [1]
Link: https://lore.kernel.org/linux-riscv/20250418022948.22853-1-looong.bin@gmail.com/ [2]
Link: https://lore.kernel.org/linux-riscv/20250424012335.6246-1-looong.bin@gmail.com/ [3]
---

Longbin Li (3):
  pwm: sophgo: reorganize the code structure
  pwm: sophgo: add driver for SG2044
  dt-bindings: pwm: sophgo: add pwm controller for SG2044

 .../bindings/pwm/sophgo,sg2042-pwm.yaml       |   4 +-
 drivers/pwm/pwm-sophgo-sg2042.c               | 151 ++++++++++++++----
 2 files changed, 125 insertions(+), 30 deletions(-)

--
2.49.0

[PATCH v4 1/3] dt-bindings: pwm: sophgo: add pwm controller for SG2044

[Longbin Li]

Add compatible string for PWM controller on SG2044.

Signed-off-by: Longbin Li <looong.bin@gmail.com>
Tested-by: Chen Wang <unicorn_wang@outlook.com>
Reviewed-by: Chen Wang <unicorn_wang@outlook.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 Documentation/devicetree/bindings/pwm/sophgo,sg2042-pwm.yaml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/pwm/sophgo,sg2042-pwm.yaml b/Documentation/devicetree/bindings/pwm/sophgo,sg2042-pwm.yaml
index bbb6326d47d7..e0e91aa237ec 100644
--- a/Documentation/devicetree/bindings/pwm/sophgo,sg2042-pwm.yaml
+++ b/Documentation/devicetree/bindings/pwm/sophgo,sg2042-pwm.yaml
@@ -17,7 +17,9 @@ allOf:

 properties:
   compatible:
-    const: sophgo,sg2042-pwm
+    enum:
+      - sophgo,sg2042-pwm
+      - sophgo,sg2044-pwm

   reg:
     maxItems: 1
--
2.49.0

[PATCH v4 2/3] pwm: sophgo: reorganize the code structure

[Longbin Li]

As the driver logic can be used in both SG2042 and SG2044, it
will be better to reorganize the code structure.

Signed-off-by: Longbin Li <looong.bin@gmail.com>
Reviewed-by: Chen Wang <unicorn_wang@outlook.com>
---
 drivers/pwm/pwm-sophgo-sg2042.c | 62 +++++++++++++++++++--------------
 1 file changed, 35 insertions(+), 27 deletions(-)

diff --git a/drivers/pwm/pwm-sophgo-sg2042.c b/drivers/pwm/pwm-sophgo-sg2042.c
index ff4639d849ce..23a83843ba53 100644
--- a/drivers/pwm/pwm-sophgo-sg2042.c
+++ b/drivers/pwm/pwm-sophgo-sg2042.c
@@ -26,18 +26,6 @@
 #include <linux/pwm.h>
 #include <linux/reset.h>

-/*
- * Offset RegisterName
- * 0x0000 HLPERIOD0
- * 0x0004 PERIOD0
- * 0x0008 HLPERIOD1
- * 0x000C PERIOD1
- * 0x0010 HLPERIOD2
- * 0x0014 PERIOD2
- * 0x0018 HLPERIOD3
- * 0x001C PERIOD3
- * Four groups and every group is composed of HLPERIOD & PERIOD
- */
 #define SG2042_PWM_HLPERIOD(chan) ((chan) * 8 + 0)
 #define SG2042_PWM_PERIOD(chan) ((chan) * 8 + 4)

@@ -53,6 +41,10 @@ struct sg2042_pwm_ddata {
 	unsigned long clk_rate_hz;
 };

+struct sg2042_chip_data {
+	const struct pwm_ops ops;
+};
+
 /*
  * period_ticks: PERIOD
  * hlperiod_ticks: HLPERIOD
@@ -66,21 +58,13 @@ static void pwm_sg2042_config(struct sg2042_pwm_ddata *ddata, unsigned int chan,
 	writel(hlperiod_ticks, base + SG2042_PWM_HLPERIOD(chan));
 }

-static int pwm_sg2042_apply(struct pwm_chip *chip, struct pwm_device *pwm,
-			    const struct pwm_state *state)
+static void pwm_set_dutycycle(struct pwm_chip *chip, struct pwm_device *pwm,
+			      const struct pwm_state *state)
 {
 	struct sg2042_pwm_ddata *ddata = pwmchip_get_drvdata(chip);
 	u32 hlperiod_ticks;
 	u32 period_ticks;

-	if (state->polarity == PWM_POLARITY_INVERSED)
-		return -EINVAL;
-
-	if (!state->enabled) {
-		pwm_sg2042_config(ddata, pwm->hwpwm, 0, 0);
-		return 0;
-	}
-
 	/*
 	 * Duration of High level (duty_cycle) = HLPERIOD x Period_of_input_clk
 	 * Duration of One Cycle (period) = PERIOD x Period_of_input_clk
@@ -92,6 +76,22 @@ static int pwm_sg2042_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 		pwm->hwpwm, period_ticks, hlperiod_ticks);

 	pwm_sg2042_config(ddata, pwm->hwpwm, period_ticks, hlperiod_ticks);
+}
+
+static int pwm_sg2042_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			    const struct pwm_state *state)
+{
+	struct sg2042_pwm_ddata *ddata = pwmchip_get_drvdata(chip);
+
+	if (state->polarity == PWM_POLARITY_INVERSED)
+		return -EINVAL;
+
+	if (!state->enabled) {
+		pwm_sg2042_config(ddata, pwm->hwpwm, 0, 0);
+		return 0;
+	}
+
+	pwm_set_dutycycle(chip, pwm, state);

 	return 0;
 }
@@ -123,13 +123,16 @@ static int pwm_sg2042_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 	return 0;
 }

-static const struct pwm_ops pwm_sg2042_ops = {
-	.apply = pwm_sg2042_apply,
-	.get_state = pwm_sg2042_get_state,
+static const struct sg2042_chip_data sg2042_chip_data = {
+	.ops = {
+		.apply = pwm_sg2042_apply,
+		.get_state = pwm_sg2042_get_state,
+	}
 };

 static const struct of_device_id sg2042_pwm_ids[] = {
-	{ .compatible = "sophgo,sg2042-pwm" },
+	{ .compatible = "sophgo,sg2042-pwm",
+	  .data = &sg2042_chip_data },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sg2042_pwm_ids);
@@ -137,12 +140,17 @@ MODULE_DEVICE_TABLE(of, sg2042_pwm_ids);
 static int pwm_sg2042_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	const struct sg2042_chip_data *chip_data;
 	struct sg2042_pwm_ddata *ddata;
 	struct reset_control *rst;
 	struct pwm_chip *chip;
 	struct clk *clk;
 	int ret;

+	chip_data = device_get_match_data(dev);
+	if (!chip_data)
+		return -ENODEV;
+
 	chip = devm_pwmchip_alloc(dev, SG2042_PWM_CHANNELNUM, sizeof(*ddata));
 	if (IS_ERR(chip))
 		return PTR_ERR(chip);
@@ -170,7 +178,7 @@ static int pwm_sg2042_probe(struct platform_device *pdev)
 	if (IS_ERR(rst))
 		return dev_err_probe(dev, PTR_ERR(rst), "Failed to get reset\n");

-	chip->ops = &pwm_sg2042_ops;
+	chip->ops = &chip_data->ops;
 	chip->atomic = true;

 	ret = devm_pwmchip_add(dev, chip);
--
2.49.0

Re: [PATCH v4 2/3] pwm: sophgo: reorganize the code structure

[Uwe Kleine-König]

[-- Attachment #1: Type: text/plain, Size: 3209 bytes --]

Hello,

On Mon, Apr 28, 2025 at 09:34:49AM +0800, Longbin Li wrote:
> As the driver logic can be used in both SG2042 and SG2044, it
> will be better to reorganize the code structure.
> 
> Signed-off-by: Longbin Li <looong.bin@gmail.com>
> Reviewed-by: Chen Wang <unicorn_wang@outlook.com>
> ---
>  drivers/pwm/pwm-sophgo-sg2042.c | 62 +++++++++++++++++++--------------
>  1 file changed, 35 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/pwm/pwm-sophgo-sg2042.c b/drivers/pwm/pwm-sophgo-sg2042.c
> index ff4639d849ce..23a83843ba53 100644
> --- a/drivers/pwm/pwm-sophgo-sg2042.c
> +++ b/drivers/pwm/pwm-sophgo-sg2042.c
> @@ -26,18 +26,6 @@
>  #include <linux/pwm.h>
>  #include <linux/reset.h>
> 
> -/*
> - * Offset RegisterName
> - * 0x0000 HLPERIOD0
> - * 0x0004 PERIOD0
> - * 0x0008 HLPERIOD1
> - * 0x000C PERIOD1
> - * 0x0010 HLPERIOD2
> - * 0x0014 PERIOD2
> - * 0x0018 HLPERIOD3
> - * 0x001C PERIOD3
> - * Four groups and every group is composed of HLPERIOD & PERIOD
> - */

This seems to be still correct? Why remove it then?

>  #define SG2042_PWM_HLPERIOD(chan) ((chan) * 8 + 0)
>  #define SG2042_PWM_PERIOD(chan) ((chan) * 8 + 4)
> 
> @@ -53,6 +41,10 @@ struct sg2042_pwm_ddata {
>  	unsigned long clk_rate_hz;
>  };
> 
> +struct sg2042_chip_data {
> +	const struct pwm_ops ops;
> +};
> +
>  /*
>   * period_ticks: PERIOD
>   * hlperiod_ticks: HLPERIOD
> @@ -66,21 +58,13 @@ static void pwm_sg2042_config(struct sg2042_pwm_ddata *ddata, unsigned int chan,
>  	writel(hlperiod_ticks, base + SG2042_PWM_HLPERIOD(chan));
>  }
> 
> -static int pwm_sg2042_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> -			    const struct pwm_state *state)
> +static void pwm_set_dutycycle(struct pwm_chip *chip, struct pwm_device *pwm,

This is not a global pwm API function, so please stick to the pwm_sg2042
prefix.

> +			      const struct pwm_state *state)
>  {
>  	struct sg2042_pwm_ddata *ddata = pwmchip_get_drvdata(chip);
>  	u32 hlperiod_ticks;
>  	u32 period_ticks;
> 
> -	if (state->polarity == PWM_POLARITY_INVERSED)
> -		return -EINVAL;
> -
> -	if (!state->enabled) {
> -		pwm_sg2042_config(ddata, pwm->hwpwm, 0, 0);
> -		return 0;
> -	}
> -
>  	/*
>  	 * Duration of High level (duty_cycle) = HLPERIOD x Period_of_input_clk
>  	 * Duration of One Cycle (period) = PERIOD x Period_of_input_clk
> [...]
> @@ -123,13 +123,16 @@ static int pwm_sg2042_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
>  	return 0;
>  }
> 
> -static const struct pwm_ops pwm_sg2042_ops = {
> -	.apply = pwm_sg2042_apply,
> -	.get_state = pwm_sg2042_get_state,
> +static const struct sg2042_chip_data sg2042_chip_data = {
> +	.ops = {
> +		.apply = pwm_sg2042_apply,
> +		.get_state = pwm_sg2042_get_state,
> +	}
>  };
> 
>  static const struct of_device_id sg2042_pwm_ids[] = {
> -	{ .compatible = "sophgo,sg2042-pwm" },
> +	{ .compatible = "sophgo,sg2042-pwm",
> +	  .data = &sg2042_chip_data },

I would have expected that checkpatch doesn't like that. At least I
don't. Please make this

	{
		.compatible = ...;
		.data = ...;
	},

>  	{ }
>  };
>  MODULE_DEVICE_TABLE(of, sg2042_pwm_ids);

[-- Attachment #2: signature.asc --]
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Re: [PATCH v4 2/3] pwm: sophgo: reorganize the code structure

[Longbin Li]

On Mon, May 26, 2025 at 04:59:34PM +0200, Uwe Kleine-König wrote:
> Hello,
> 
> On Mon, Apr 28, 2025 at 09:34:49AM +0800, Longbin Li wrote:
> > As the driver logic can be used in both SG2042 and SG2044, it
> > will be better to reorganize the code structure.
> > 
> > Signed-off-by: Longbin Li <looong.bin@gmail.com>
> > Reviewed-by: Chen Wang <unicorn_wang@outlook.com>
> > ---
> >  drivers/pwm/pwm-sophgo-sg2042.c | 62 +++++++++++++++++++--------------
> >  1 file changed, 35 insertions(+), 27 deletions(-)
> > 
> > diff --git a/drivers/pwm/pwm-sophgo-sg2042.c b/drivers/pwm/pwm-sophgo-sg2042.c
> > index ff4639d849ce..23a83843ba53 100644
> > --- a/drivers/pwm/pwm-sophgo-sg2042.c
> > +++ b/drivers/pwm/pwm-sophgo-sg2042.c
> > @@ -26,18 +26,6 @@
> >  #include <linux/pwm.h>
> >  #include <linux/reset.h>
> > 
> > -/*
> > - * Offset RegisterName
> > - * 0x0000 HLPERIOD0
> > - * 0x0004 PERIOD0
> > - * 0x0008 HLPERIOD1
> > - * 0x000C PERIOD1
> > - * 0x0010 HLPERIOD2
> > - * 0x0014 PERIOD2
> > - * 0x0018 HLPERIOD3
> > - * 0x001C PERIOD3
> > - * Four groups and every group is composed of HLPERIOD & PERIOD
> > - */
> 
> This seems to be still correct? Why remove it then?
> 

The following "#define" has already expressd it. For clarity,
i will add it back.

> >  #define SG2042_PWM_HLPERIOD(chan) ((chan) * 8 + 0)
> >  #define SG2042_PWM_PERIOD(chan) ((chan) * 8 + 4)
> > 
> > @@ -53,6 +41,10 @@ struct sg2042_pwm_ddata {
> >  	unsigned long clk_rate_hz;
> >  };
> > 
> > +struct sg2042_chip_data {
> > +	const struct pwm_ops ops;
> > +};
> > +
> >  /*
> >   * period_ticks: PERIOD
> >   * hlperiod_ticks: HLPERIOD
> > @@ -66,21 +58,13 @@ static void pwm_sg2042_config(struct sg2042_pwm_ddata *ddata, unsigned int chan,
> >  	writel(hlperiod_ticks, base + SG2042_PWM_HLPERIOD(chan));
> >  }
> > 
> > -static int pwm_sg2042_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> > -			    const struct pwm_state *state)
> > +static void pwm_set_dutycycle(struct pwm_chip *chip, struct pwm_device *pwm,
> 
> This is not a global pwm API function, so please stick to the pwm_sg2042
> prefix.
> 

I will modify that, thanks.

> > +			      const struct pwm_state *state)
> >  {
> >  	struct sg2042_pwm_ddata *ddata = pwmchip_get_drvdata(chip);
> >  	u32 hlperiod_ticks;
> >  	u32 period_ticks;
> > 
> > -	if (state->polarity == PWM_POLARITY_INVERSED)
> > -		return -EINVAL;
> > -
> > -	if (!state->enabled) {
> > -		pwm_sg2042_config(ddata, pwm->hwpwm, 0, 0);
> > -		return 0;
> > -	}
> > -
> >  	/*
> >  	 * Duration of High level (duty_cycle) = HLPERIOD x Period_of_input_clk
> >  	 * Duration of One Cycle (period) = PERIOD x Period_of_input_clk
> > [...]
> > @@ -123,13 +123,16 @@ static int pwm_sg2042_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
> >  	return 0;
> >  }
> > 
> > -static const struct pwm_ops pwm_sg2042_ops = {
> > -	.apply = pwm_sg2042_apply,
> > -	.get_state = pwm_sg2042_get_state,
> > +static const struct sg2042_chip_data sg2042_chip_data = {
> > +	.ops = {
> > +		.apply = pwm_sg2042_apply,
> > +		.get_state = pwm_sg2042_get_state,
> > +	}
> >  };
> > 
> >  static const struct of_device_id sg2042_pwm_ids[] = {
> > -	{ .compatible = "sophgo,sg2042-pwm" },
> > +	{ .compatible = "sophgo,sg2042-pwm",
> > +	  .data = &sg2042_chip_data },
> 
> I would have expected that checkpatch doesn't like that. At least I
> don't. Please make this
> 
> 	{
> 		.compatible = ...;
> 		.data = ...;
> 	},
> 

I will check that, thanks.

> >  	{ }
> >  };
> >  MODULE_DEVICE_TABLE(of, sg2042_pwm_ids);

[PATCH v4 3/3] pwm: sophgo: add driver for SG2044

[Longbin Li]

Add PWM controller for SG2044 on base of SG2042.

Signed-off-by: Longbin Li <looong.bin@gmail.com>
Reviewed-by: Chen Wang <unicorn_wang@outlook.com>
---
 drivers/pwm/pwm-sophgo-sg2042.c | 89 ++++++++++++++++++++++++++++++++-
 1 file changed, 87 insertions(+), 2 deletions(-)

diff --git a/drivers/pwm/pwm-sophgo-sg2042.c b/drivers/pwm/pwm-sophgo-sg2042.c
index 23a83843ba53..5bb92c910540 100644
--- a/drivers/pwm/pwm-sophgo-sg2042.c
+++ b/drivers/pwm/pwm-sophgo-sg2042.c
@@ -13,6 +13,9 @@
  *   the running period.
  * - When PERIOD and HLPERIOD is set to 0, the PWM wave output will
  *   be stopped and the output is pulled to high.
+ * - SG2044 support polarity while SG2042 does not. When PWMSTART is
+ *   false, POLARITY being NORMAL will make output being low,
+ *   POLARITY being INVERSED will make output being high.
  * See the datasheet [1] for more details.
  * [1]:https://github.com/sophgo/sophgo-doc/tree/main/SG2042/TRM
  */
@@ -26,6 +29,10 @@
 #include <linux/pwm.h>
 #include <linux/reset.h>

+#define SG2044_PWM_POLARITY		0x40
+#define SG2044_PWM_PWMSTART		0x44
+#define SG2044_PWM_OE			0xd0
+
 #define SG2042_PWM_HLPERIOD(chan) ((chan) * 8 + 0)
 #define SG2042_PWM_PERIOD(chan) ((chan) * 8 + 4)

@@ -72,8 +79,8 @@ static void pwm_set_dutycycle(struct pwm_chip *chip, struct pwm_device *pwm,
 	period_ticks = min(mul_u64_u64_div_u64(ddata->clk_rate_hz, state->period, NSEC_PER_SEC), U32_MAX);
 	hlperiod_ticks = min(mul_u64_u64_div_u64(ddata->clk_rate_hz, state->duty_cycle, NSEC_PER_SEC), U32_MAX);

-	dev_dbg(pwmchip_parent(chip), "chan[%u]: PERIOD=%u, HLPERIOD=%u\n",
-		pwm->hwpwm, period_ticks, hlperiod_ticks);
+	dev_dbg(pwmchip_parent(chip), "chan[%u]: ENABLE=%u, PERIOD=%u, HLPERIOD=%u, POLARITY=%u\n",
+		pwm->hwpwm, state->enabled, period_ticks, hlperiod_ticks, state->polarity);

 	pwm_sg2042_config(ddata, pwm->hwpwm, period_ticks, hlperiod_ticks);
 }
@@ -123,6 +130,74 @@ static int pwm_sg2042_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 	return 0;
 }

+static void pwm_sg2044_set_start(struct sg2042_pwm_ddata *ddata, struct pwm_device *pwm,
+				 bool enabled)
+{
+	u32 pwm_value;
+
+	pwm_value = readl(ddata->base + SG2044_PWM_PWMSTART);
+
+	if (enabled)
+		pwm_value |= BIT(pwm->hwpwm);
+	else
+		pwm_value &= ~BIT(pwm->hwpwm);
+
+	writel(pwm_value, ddata->base + SG2044_PWM_PWMSTART);
+}
+
+static void pwm_sg2044_set_outputdir(struct sg2042_pwm_ddata *ddata, struct pwm_device *pwm,
+				     bool enabled)
+{
+	u32 pwm_value;
+
+	pwm_value = readl(ddata->base + SG2044_PWM_OE);
+
+	if (enabled)
+		pwm_value |= BIT(pwm->hwpwm);
+	else
+		pwm_value &= ~BIT(pwm->hwpwm);
+
+	writel(pwm_value, ddata->base + SG2044_PWM_OE);
+}
+
+static void pwm_sg2044_set_polarity(struct sg2042_pwm_ddata *ddata, struct pwm_device *pwm,
+				    const struct pwm_state *state)
+{
+	u32 pwm_value;
+
+	pwm_value = readl(ddata->base + SG2044_PWM_POLARITY);
+
+	if (state->polarity == PWM_POLARITY_NORMAL)
+		pwm_value &= ~BIT(pwm->hwpwm);
+	else
+		pwm_value |= BIT(pwm->hwpwm);
+
+	writel(pwm_value, ddata->base + SG2044_PWM_POLARITY);
+}
+
+static int pwm_sg2044_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			    const struct pwm_state *state)
+{
+	struct sg2042_pwm_ddata *ddata = pwmchip_get_drvdata(chip);
+
+	pwm_sg2044_set_polarity(ddata, pwm, state);
+
+	pwm_set_dutycycle(chip, pwm, state);
+
+	/*
+	 * re-enable PWMSTART to refresh the register period
+	 */
+	pwm_sg2044_set_start(ddata, pwm, false);
+
+	if (!state->enabled)
+		return 0;
+
+	pwm_sg2044_set_outputdir(ddata, pwm, true);
+	pwm_sg2044_set_start(ddata, pwm, true);
+
+	return 0;
+}
+
 static const struct sg2042_chip_data sg2042_chip_data = {
 	.ops = {
 		.apply = pwm_sg2042_apply,
@@ -130,9 +205,18 @@ static const struct sg2042_chip_data sg2042_chip_data = {
 	}
 };

+static const struct sg2042_chip_data sg2044_chip_data = {
+	.ops = {
+		.apply = pwm_sg2044_apply,
+		.get_state = pwm_sg2042_get_state,
+	}
+};
+
 static const struct of_device_id sg2042_pwm_ids[] = {
 	{ .compatible = "sophgo,sg2042-pwm",
 	  .data = &sg2042_chip_data },
+	{ .compatible = "sophgo,sg2044-pwm",
+	  .data = &sg2044_chip_data },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sg2042_pwm_ids);
@@ -198,5 +282,6 @@ static struct platform_driver pwm_sg2042_driver = {
 module_platform_driver(pwm_sg2042_driver);

 MODULE_AUTHOR("Chen Wang");
+MODULE_AUTHOR("Longbin Li <looong.bin@gmail.com>");
 MODULE_DESCRIPTION("Sophgo SG2042 PWM driver");
 MODULE_LICENSE("GPL");
--
2.49.0

Re: [PATCH v4 3/3] pwm: sophgo: add driver for SG2044

[Uwe Kleine-König]

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On Mon, Apr 28, 2025 at 09:34:50AM +0800, Longbin Li wrote:
> Add PWM controller for SG2044 on base of SG2042.
> 
> Signed-off-by: Longbin Li <looong.bin@gmail.com>
> Reviewed-by: Chen Wang <unicorn_wang@outlook.com>
> ---
>  drivers/pwm/pwm-sophgo-sg2042.c | 89 ++++++++++++++++++++++++++++++++-
>  1 file changed, 87 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pwm/pwm-sophgo-sg2042.c b/drivers/pwm/pwm-sophgo-sg2042.c
> index 23a83843ba53..5bb92c910540 100644
> --- a/drivers/pwm/pwm-sophgo-sg2042.c
> +++ b/drivers/pwm/pwm-sophgo-sg2042.c
> @@ -13,6 +13,9 @@
>   *   the running period.
>   * - When PERIOD and HLPERIOD is set to 0, the PWM wave output will
>   *   be stopped and the output is pulled to high.
> + * - SG2044 support polarity while SG2042 does not. When PWMSTART is
> + *   false, POLARITY being NORMAL will make output being low,
> + *   POLARITY being INVERSED will make output being high.

Without detailed knowledge about the hardware this isn't understandable.
What is PWMSTART? I think this can just read:

	SG2044 supports both polarities, SG2042 only normal polarity.

The rest is an implementation detail.

>   * See the datasheet [1] for more details.
>   * [1]:https://github.com/sophgo/sophgo-doc/tree/main/SG2042/TRM

This only describes SG2042, right? Can you please add a link for the new
variant?

>   */
> @@ -26,6 +29,10 @@
>  #include <linux/pwm.h>
>  #include <linux/reset.h>
> 
> +#define SG2044_PWM_POLARITY		0x40
> +#define SG2044_PWM_PWMSTART		0x44
> +#define SG2044_PWM_OE			0xd0
> +
>  #define SG2042_PWM_HLPERIOD(chan) ((chan) * 8 + 0)
>  #define SG2042_PWM_PERIOD(chan) ((chan) * 8 + 4)
> 
> @@ -72,8 +79,8 @@ static void pwm_set_dutycycle(struct pwm_chip *chip, struct pwm_device *pwm,
>  	period_ticks = min(mul_u64_u64_div_u64(ddata->clk_rate_hz, state->period, NSEC_PER_SEC), U32_MAX);
>  	hlperiod_ticks = min(mul_u64_u64_div_u64(ddata->clk_rate_hz, state->duty_cycle, NSEC_PER_SEC), U32_MAX);
> 
> -	dev_dbg(pwmchip_parent(chip), "chan[%u]: PERIOD=%u, HLPERIOD=%u\n",
> -		pwm->hwpwm, period_ticks, hlperiod_ticks);
> +	dev_dbg(pwmchip_parent(chip), "chan[%u]: ENABLE=%u, PERIOD=%u, HLPERIOD=%u, POLARITY=%u\n",
> +		pwm->hwpwm, state->enabled, period_ticks, hlperiod_ticks, state->polarity);
> 
>  	pwm_sg2042_config(ddata, pwm->hwpwm, period_ticks, hlperiod_ticks);
>  }
> @@ -123,6 +130,74 @@ static int pwm_sg2042_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
>  	return 0;
>  }
> 
> +static void pwm_sg2044_set_start(struct sg2042_pwm_ddata *ddata, struct pwm_device *pwm,
> +				 bool enabled)
> +{
> +	u32 pwm_value;
> +
> +	pwm_value = readl(ddata->base + SG2044_PWM_PWMSTART);

Please use a variable name that matches the register this is used for.

> +	if (enabled)
> +		pwm_value |= BIT(pwm->hwpwm);
> +	else
> +		pwm_value &= ~BIT(pwm->hwpwm);
> +
> +	writel(pwm_value, ddata->base + SG2044_PWM_PWMSTART);
> +}
> +
> +static void pwm_sg2044_set_outputdir(struct sg2042_pwm_ddata *ddata, struct pwm_device *pwm,
> +				     bool enabled)
> +{
> +	u32 pwm_value;
> +
> +	pwm_value = readl(ddata->base + SG2044_PWM_OE);
> +
> +	if (enabled)
> +		pwm_value |= BIT(pwm->hwpwm);
> +	else
> +		pwm_value &= ~BIT(pwm->hwpwm);
> +
> +	writel(pwm_value, ddata->base + SG2044_PWM_OE);
> +}
> +
> +static void pwm_sg2044_set_polarity(struct sg2042_pwm_ddata *ddata, struct pwm_device *pwm,
> +				    const struct pwm_state *state)
> +{
> +	u32 pwm_value;
> +
> +	pwm_value = readl(ddata->base + SG2044_PWM_POLARITY);
> +
> +	if (state->polarity == PWM_POLARITY_NORMAL)
> +		pwm_value &= ~BIT(pwm->hwpwm);
> +	else
> +		pwm_value |= BIT(pwm->hwpwm);
> +
> +	writel(pwm_value, ddata->base + SG2044_PWM_POLARITY);
> +}
> +
> +static int pwm_sg2044_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> +			    const struct pwm_state *state)
> +{
> +	struct sg2042_pwm_ddata *ddata = pwmchip_get_drvdata(chip);
> +
> +	pwm_sg2044_set_polarity(ddata, pwm, state);
> +
> +	pwm_set_dutycycle(chip, pwm, state);
> +
> +	/*
> +	 * re-enable PWMSTART to refresh the register period
> +	 */
> +	pwm_sg2044_set_start(ddata, pwm, false);

I don't understand the effect of the START register. 

> +	if (!state->enabled)
> +		return 0;
> +
> +	pwm_sg2044_set_outputdir(ddata, pwm, true);
> +	pwm_sg2044_set_start(ddata, pwm, true);
> +
> +	return 0;
> +}
> +
>  static const struct sg2042_chip_data sg2042_chip_data = {
>  	.ops = {
>  		.apply = pwm_sg2042_apply,

Best regards
Uwe

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Re: [PATCH v4 3/3] pwm: sophgo: add driver for SG2044

[Longbin Li]

On Mon, May 26, 2025 at 05:06:25PM +0200, Uwe Kleine-König wrote:
> On Mon, Apr 28, 2025 at 09:34:50AM +0800, Longbin Li wrote:
> > Add PWM controller for SG2044 on base of SG2042.
> > 
> > Signed-off-by: Longbin Li <looong.bin@gmail.com>
> > Reviewed-by: Chen Wang <unicorn_wang@outlook.com>
> > ---
> >  drivers/pwm/pwm-sophgo-sg2042.c | 89 ++++++++++++++++++++++++++++++++-
> >  1 file changed, 87 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/pwm/pwm-sophgo-sg2042.c b/drivers/pwm/pwm-sophgo-sg2042.c
> > index 23a83843ba53..5bb92c910540 100644
> > --- a/drivers/pwm/pwm-sophgo-sg2042.c
> > +++ b/drivers/pwm/pwm-sophgo-sg2042.c
> > @@ -13,6 +13,9 @@
> >   *   the running period.
> >   * - When PERIOD and HLPERIOD is set to 0, the PWM wave output will
> >   *   be stopped and the output is pulled to high.
> > + * - SG2044 support polarity while SG2042 does not. When PWMSTART is
> > + *   false, POLARITY being NORMAL will make output being low,
> > + *   POLARITY being INVERSED will make output being high.
> 
> Without detailed knowledge about the hardware this isn't understandable.
> What is PWMSTART? I think this can just read:
> 
> 	SG2044 supports both polarities, SG2042 only normal polarity.
> 
> The rest is an implementation detail.
>

I will modify that, thanks.
 
> >   * See the datasheet [1] for more details.
> >   * [1]:https://github.com/sophgo/sophgo-doc/tree/main/SG2042/TRM
> 
> This only describes SG2042, right? Can you please add a link for the new
> variant?
> 

Sorry, there is no public document for SG2044.

> >   */
> > @@ -26,6 +29,10 @@
> >  #include <linux/pwm.h>
> >  #include <linux/reset.h>
> > 
> > +#define SG2044_PWM_POLARITY		0x40
> > +#define SG2044_PWM_PWMSTART		0x44
> > +#define SG2044_PWM_OE			0xd0
> > +
> >  #define SG2042_PWM_HLPERIOD(chan) ((chan) * 8 + 0)
> >  #define SG2042_PWM_PERIOD(chan) ((chan) * 8 + 4)
> > 
> > @@ -72,8 +79,8 @@ static void pwm_set_dutycycle(struct pwm_chip *chip, struct pwm_device *pwm,
> >  	period_ticks = min(mul_u64_u64_div_u64(ddata->clk_rate_hz, state->period, NSEC_PER_SEC), U32_MAX);
> >  	hlperiod_ticks = min(mul_u64_u64_div_u64(ddata->clk_rate_hz, state->duty_cycle, NSEC_PER_SEC), U32_MAX);
> > 
> > -	dev_dbg(pwmchip_parent(chip), "chan[%u]: PERIOD=%u, HLPERIOD=%u\n",
> > -		pwm->hwpwm, period_ticks, hlperiod_ticks);
> > +	dev_dbg(pwmchip_parent(chip), "chan[%u]: ENABLE=%u, PERIOD=%u, HLPERIOD=%u, POLARITY=%u\n",
> > +		pwm->hwpwm, state->enabled, period_ticks, hlperiod_ticks, state->polarity);
> > 
> >  	pwm_sg2042_config(ddata, pwm->hwpwm, period_ticks, hlperiod_ticks);
> >  }
> > @@ -123,6 +130,74 @@ static int pwm_sg2042_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
> >  	return 0;
> >  }
> > 
> > +static void pwm_sg2044_set_start(struct sg2042_pwm_ddata *ddata, struct pwm_device *pwm,
> > +				 bool enabled)
> > +{
> > +	u32 pwm_value;
> > +
> > +	pwm_value = readl(ddata->base + SG2044_PWM_PWMSTART);
> 
> Please use a variable name that matches the register this is used for.
> 

I will fix that.

> > +	if (enabled)
> > +		pwm_value |= BIT(pwm->hwpwm);
> > +	else
> > +		pwm_value &= ~BIT(pwm->hwpwm);
> > +
> > +	writel(pwm_value, ddata->base + SG2044_PWM_PWMSTART);
> > +}
> > +
> > +static void pwm_sg2044_set_outputdir(struct sg2042_pwm_ddata *ddata, struct pwm_device *pwm,
> > +				     bool enabled)
> > +{
> > +	u32 pwm_value;
> > +
> > +	pwm_value = readl(ddata->base + SG2044_PWM_OE);
> > +
> > +	if (enabled)
> > +		pwm_value |= BIT(pwm->hwpwm);
> > +	else
> > +		pwm_value &= ~BIT(pwm->hwpwm);
> > +
> > +	writel(pwm_value, ddata->base + SG2044_PWM_OE);
> > +}
> > +
> > +static void pwm_sg2044_set_polarity(struct sg2042_pwm_ddata *ddata, struct pwm_device *pwm,
> > +				    const struct pwm_state *state)
> > +{
> > +	u32 pwm_value;
> > +
> > +	pwm_value = readl(ddata->base + SG2044_PWM_POLARITY);
> > +
> > +	if (state->polarity == PWM_POLARITY_NORMAL)
> > +		pwm_value &= ~BIT(pwm->hwpwm);
> > +	else
> > +		pwm_value |= BIT(pwm->hwpwm);
> > +
> > +	writel(pwm_value, ddata->base + SG2044_PWM_POLARITY);
> > +}
> > +
> > +static int pwm_sg2044_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> > +			    const struct pwm_state *state)
> > +{
> > +	struct sg2042_pwm_ddata *ddata = pwmchip_get_drvdata(chip);
> > +
> > +	pwm_sg2044_set_polarity(ddata, pwm, state);
> > +
> > +	pwm_set_dutycycle(chip, pwm, state);
> > +
> > +	/*
> > +	 * re-enable PWMSTART to refresh the register period
> > +	 */
> > +	pwm_sg2044_set_start(ddata, pwm, false);
> 
> I don't understand the effect of the START register. 
> 

PWMSTART[3:0] enable the output of the corresponding channel. Must re-enable
it to refresh the register period when changed the duty cycle. I will find 
a better name, thanks.

> > +	if (!state->enabled)
> > +		return 0;
> > +
> > +	pwm_sg2044_set_outputdir(ddata, pwm, true);
> > +	pwm_sg2044_set_start(ddata, pwm, true);
> > +
> > +	return 0;
> > +}
> > +
> >  static const struct sg2042_chip_data sg2042_chip_data = {
> >  	.ops = {
> >  		.apply = pwm_sg2042_apply,
> 
> Best regards
> Uwe

Re: [PATCH v4 0/3] riscv: pwm: sophgo: add pwm support for SG2044

[Chen Wang]

Seems only tag changes. LGTM.

Thanks,

Chen

On 2025/4/28 9:34, Longbin Li wrote:
> This patch adds PWM controller support for four independent
> PWM channel outputs.
>
> ---
>
> Changes in v4:
>
>    - add tags for mail.
>
> Changes in v3:
>    You can simply review or test the patches at the link [3].
>
>    - Rename macro definitions to unify naming.
>    - Modify code style.
>
> Changes in v2:
>    You can simply review or test the patches at the link [2].
>
>    - Modify variable naming and code logic.
>    - update "MODULE_AUTHOR".
>
> Changes in v1:
>    You can simply review or test the patches at the link [1].
>
> Link: https://lore.kernel.org/linux-riscv/20250407072056.8629-1-looong.bin@gmail.com/ [1]
> Link: https://lore.kernel.org/linux-riscv/20250418022948.22853-1-looong.bin@gmail.com/ [2]
> Link: https://lore.kernel.org/linux-riscv/20250424012335.6246-1-looong.bin@gmail.com/ [3]
> ---
>
> Longbin Li (3):
>    pwm: sophgo: reorganize the code structure
>    pwm: sophgo: add driver for SG2044
>    dt-bindings: pwm: sophgo: add pwm controller for SG2044
>
>   .../bindings/pwm/sophgo,sg2042-pwm.yaml       |   4 +-
>   drivers/pwm/pwm-sophgo-sg2042.c               | 151 ++++++++++++++----
>   2 files changed, 125 insertions(+), 30 deletions(-)
>
> --
> 2.49.0