[PATCH 0/2] Add driver support for ESWIN EIC7700 PWM controller

[PATCH 0/2] Add driver support for ESWIN EIC7700 PWM controller

[dongxuyang]

From: Xuyang Dong <dongxuyang@eswincomputing.com>

Add support for the ESWIN EIC7700 PWM (Pulse Width Modulation) based on
Synopsys DWC PWM.

Features:
The EIC7700 PWM driver supports a duty cycle range from 0% to 100%, with
explicit support added for both 0% and 100% duty cycles.

Supported chips:
ESWIN EIC7700 series SoC.

Test:
Tested this patch on the Sifive HiFive Premier P550 (which used the EIC7700
SoC).

Xuyang Dong (2):
  dt-bindings: pwm: eswin: Add EIC7700 pwm controller
  pwm: eswin: Add EIC7700 pwm driver

 .../bindings/pwm/eswin,eic7700-pwm.yaml       |  73 ++++++
 drivers/pwm/Kconfig                           |  12 +
 drivers/pwm/Makefile                          |   1 +
 drivers/pwm/pwm-dwc-core.c                    |  76 ++++--
 drivers/pwm/pwm-dwc-eic7700.c                 | 231 ++++++++++++++++++
 drivers/pwm/pwm-dwc.h                         |  16 +-
 6 files changed, 384 insertions(+), 25 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/pwm/eswin,eic7700-pwm.yaml
 create mode 100644 drivers/pwm/pwm-dwc-eic7700.c

--
2.34.1

[PATCH 1/2] dt-bindings: pwm: eswin: Add EIC7700 pwm controller

[dongxuyang]

From: Xuyang Dong <dongxuyang@eswincomputing.com>

Introduce device-tree binding documentation for ESWIN EIC7700 pwm
controller.

Signed-off-by: Xiang Xu <xuxiang@eswincomputing.com>
Signed-off-by: Guosheng Wang <wangguosheng@eswincomputing.com>
Signed-off-by: Xuyang Dong <dongxuyang@eswincomputing.com>
---
 .../bindings/pwm/eswin,eic7700-pwm.yaml       | 73 +++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/eswin,eic7700-pwm.yaml

diff --git a/Documentation/devicetree/bindings/pwm/eswin,eic7700-pwm.yaml b/Documentation/devicetree/bindings/pwm/eswin,eic7700-pwm.yaml
new file mode 100644
index 000000000000..8b7dc7d4dffe
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/eswin,eic7700-pwm.yaml
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/eswin,eic7700-pwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ESWIN EIC7700 PWM controller
+
+maintainers:
+  - Xiang Xu <xuxiang@eswincomputing.com>
+  - Guosheng Wang <wangguosheng@eswincomputing.com>
+  - Xuyang Dong <dongxuyang@eswincomputing.com>
+
+description: |
+  The EIC7700 PWM used the DesignWare APB timers module. The PWM driver
+  supports a duty cycle range from 0% to 100%, with explicit support for
+  both 0% and 100% duty cycles.
+
+allOf:
+  - $ref: pwm.yaml#
+
+properties:
+  compatible:
+    const: eswin,eic7700-pwm
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  "#pwm-cells":
+    const: 3
+
+  pinctrl-0: true
+  pinctrl-1: true
+
+  pinctrl-names:
+    minItems: 1
+    items:
+      - const: default
+      - const: sleep
+
+  snps,pwm-full-range-enable:
+    type: boolean
+    description: |
+      Enable support for 0% and 100% duty cycle.
+      When present, the PWM controller can output 0% and 100% duty cycles.
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - resets
+  - snps,pwm-full-range-enable
+
+additionalProperties: false
+
+examples:
+  - |
+    pwm@50818000 {
+        compatible = "eswin,eic7700-pwm";
+        reg = <0x50818000 0x4000>;
+        clocks = <&clock 242>;
+        resets = <&reset 136>;
+        #pwm-cells = <3>;
+        pinctrl-names = "default";
+        pinctrl-0 = <&fan_pwm>;
+        snps,pwm-full-range-enable;
+    };
-- 
2.34.1

Re: [PATCH 1/2] dt-bindings: pwm: eswin: Add EIC7700 pwm controller

[Krzysztof Kozlowski]

On Fri, Dec 05, 2025 at 05:04:50PM +0800, dongxuyang@eswincomputing.com wrote:
> diff --git a/Documentation/devicetree/bindings/pwm/eswin,eic7700-pwm.yaml b/Documentation/devicetree/bindings/pwm/eswin,eic7700-pwm.yaml
> new file mode 100644
> index 000000000000..8b7dc7d4dffe
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/eswin,eic7700-pwm.yaml
> @@ -0,0 +1,73 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pwm/eswin,eic7700-pwm.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ESWIN EIC7700 PWM controller
> +
> +maintainers:
> +  - Xiang Xu <xuxiang@eswincomputing.com>
> +  - Guosheng Wang <wangguosheng@eswincomputing.com>
> +  - Xuyang Dong <dongxuyang@eswincomputing.com>
> +
> +description: |

Do not need '|' unless you need to preserve formatting.

> +  The EIC7700 PWM used the DesignWare APB timers module. The PWM driver
> +  supports a duty cycle range from 0% to 100%, with explicit support for

Driver is irrelevant here. Describe hardware.

> +  both 0% and 100% duty cycles.
> +
> +allOf:
> +  - $ref: pwm.yaml#
> +
> +properties:
> +  compatible:
> +    const: eswin,eic7700-pwm
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  resets:
> +    maxItems: 1
> +
> +  "#pwm-cells":
> +    const: 3
> +
> +  pinctrl-0: true
> +  pinctrl-1: true
> +
> +  pinctrl-names:
> +    minItems: 1
> +    items:
> +      - const: default
> +      - const: sleep
> +
> +  snps,pwm-full-range-enable:

1. Wrong vendor prefix, thats eswin, not snps.
2. Why is this a hardware property? I really do not see that. You
described the desired Linux feature or behavior, not the actual
hardware. The bindings are about the latter, so instead you need to
rephrase the property and its description to match actual hardware
capabilities/features/configuration etc.

Best regards,
Krzysztof

Re: Re: [PATCH 1/2] dt-bindings: pwm: eswin: Add EIC7700 pwm controller

[Xuyang Dong]

> > diff --git a/Documentation/devicetree/bindings/pwm/eswin,eic7700-pwm.yaml b/Documentation/devicetree/bindings/pwm/eswin,eic7700-pwm.yaml
> > new file mode 100644
> > index 000000000000..8b7dc7d4dffe
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pwm/eswin,eic7700-pwm.yaml
> > @@ -0,0 +1,73 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/pwm/eswin,eic7700-pwm.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: ESWIN EIC7700 PWM controller
> > +
> > +maintainers:
> > +  - Xiang Xu <xuxiang@eswincomputing.com>
> > +  - Guosheng Wang <wangguosheng@eswincomputing.com>
> > +  - Xuyang Dong <dongxuyang@eswincomputing.com>
> > +
> > +description: |
> 
> Do not need '|' unless you need to preserve formatting.
> 
> > +  The EIC7700 PWM used the DesignWare APB timers module. The PWM driver
> > +  supports a duty cycle range from 0% to 100%, with explicit support for
> 
> Driver is irrelevant here. Describe hardware.
> 
> > +  both 0% and 100% duty cycles.
> > +
> > +allOf:
> > +  - $ref: pwm.yaml#
> > +
> > +properties:
> > +  compatible:
> > +    const: eswin,eic7700-pwm
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    maxItems: 1
> > +
> > +  resets:
> > +    maxItems: 1
> > +
> > +  "#pwm-cells":
> > +    const: 3
> > +
> > +  pinctrl-0: true
> > +  pinctrl-1: true
> > +
> > +  pinctrl-names:
> > +    minItems: 1
> > +    items:
> > +      - const: default
> > +      - const: sleep
> > +
> > +  snps,pwm-full-range-enable:
> 
> 1. Wrong vendor prefix, thats eswin, not snps.
> 2. Why is this a hardware property? I really do not see that. You
> described the desired Linux feature or behavior, not the actual
> hardware. The bindings are about the latter, so instead you need to
> rephrase the property and its description to match actual hardware
> capabilities/features/configuration etc.
> 
Hi Krzysztof and Ben,

There is a patch [1] submmitted by Ben Dook a few years ago. The 
intention of this patch is to make DWC pwm controller can be used as 
platform driver. This is what we are currently working on.
It seems that it would be more reasonable to continue improving this 
patch and make the DWC PWM driver universal, rather than creating a 
separate ESWIN PWM driver.

The DWC pwm 2.13a version supports "Pulse Width Modulation with 0% and 
100% Duty Cycle" by programming TIMER_0N100PWM_EN bit field. We also 
want to support this new hardware feature. So, adding a new property, 
like snps,timer-0n100pwm-en, in pwm/snps,dw-apb-timers-pwm2.yaml
would be better?

Krzysztof and Ben, do you think the above approach is reasonable and acceptable?

[1] https://lore.kernel.org/lkml/20230907161242.67190-7-ben.dooks@codethink.co.uk/

Regards,
Xuyang Dong

Re: [PATCH 1/2] dt-bindings: pwm: eswin: Add EIC7700 pwm controller

[Krzysztof Kozlowski]

On 09/12/2025 11:20, Xuyang Dong wrote:
>>> +
>>> +  pinctrl-0: true
>>> +  pinctrl-1: true
>>> +
>>> +  pinctrl-names:
>>> +    minItems: 1
>>> +    items:
>>> +      - const: default
>>> +      - const: sleep
>>> +
>>> +  snps,pwm-full-range-enable:
>>
>> 1. Wrong vendor prefix, thats eswin, not snps.
>> 2. Why is this a hardware property? I really do not see that. You
>> described the desired Linux feature or behavior, not the actual
>> hardware. The bindings are about the latter, so instead you need to
>> rephrase the property and its description to match actual hardware
>> capabilities/features/configuration etc.
>>
> Hi Krzysztof and Ben,
> 
> There is a patch [1] submmitted by Ben Dook a few years ago. The 
> intention of this patch is to make DWC pwm controller can be used as 
> platform driver. This is what we are currently working on.
> It seems that it would be more reasonable to continue improving this 
> patch and make the DWC PWM driver universal, rather than creating a 
> separate ESWIN PWM driver.
> 
> The DWC pwm 2.13a version supports "Pulse Width Modulation with 0% and 
> 100% Duty Cycle" by programming TIMER_0N100PWM_EN bit field. We also 
> want to support this new hardware feature. So, adding a new property, 
> like snps,timer-0n100pwm-en, in pwm/snps,dw-apb-timers-pwm2.yaml
> would be better?
> 
> Krzysztof and Ben, do you think the above approach is reasonable and acceptable?


How any of this is related to the binding? We talk here about hardware
and binding, but you ask me about driver.... I don't care.

Best regards,
Krzysztof

[PATCH 2/2] pwm: eswin: Add EIC7700 pwm driver

[dongxuyang]

From: Xuyang Dong <dongxuyang@eswincomputing.com>

Introduce driver for PWM module available on EIC7700 SoC.
Add snps,pwm-0-n-100-percent flag to support for both
0% and 100% duty cycles. And remove this flag to support
the duty cycle range from 0% to 100%.

Signed-off-by: Xiang Xu <xuxiang@eswincomputing.com>
Signed-off-by: Guosheng Wang <wangguosheng@eswincomputing.com>
Signed-off-by: Xuyang Dong <dongxuyang@eswincomputing.com>
---
 drivers/pwm/Kconfig           |  12 ++
 drivers/pwm/Makefile          |   1 +
 drivers/pwm/pwm-dwc-core.c    |  76 ++++++++---
 drivers/pwm/pwm-dwc-eic7700.c | 231 ++++++++++++++++++++++++++++++++++
 drivers/pwm/pwm-dwc.h         |  16 ++-
 5 files changed, 311 insertions(+), 25 deletions(-)
 create mode 100644 drivers/pwm/pwm-dwc-eic7700.c

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index bf2d101f67a1..c2cf0d9c9854 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -249,6 +249,18 @@ config PWM_DWC
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-dwc.
 
+config PWM_EIC7700
+	tristate "EIC7700 PWM Controller"
+	depends on ARCH_ESWIN || COMPILE_TEST
+	depends on HAS_IOMEM
+	select PWM_DWC_CORE
+	help
+	  PWM driver for Synopsys DWC PWM Controller on a platform for EIC7700
+	  SoCs.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-dwc-eic7700.
+
 config PWM_EP93XX
 	tristate "Cirrus Logic EP93xx PWM support"
 	depends on ARCH_EP93XX || COMPILE_TEST
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 0dc0d2b69025..2b4b7a5c5b15 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_PWM_CRC)		+= pwm-crc.o
 obj-$(CONFIG_PWM_CROS_EC)	+= pwm-cros-ec.o
 obj-$(CONFIG_PWM_DWC_CORE)	+= pwm-dwc-core.o
 obj-$(CONFIG_PWM_DWC)		+= pwm-dwc.o
+obj-$(CONFIG_PWM_EIC7700)	+= pwm-dwc-eic7700.o
 obj-$(CONFIG_PWM_EP93XX)	+= pwm-ep93xx.o
 obj-$(CONFIG_PWM_FSL_FTM)	+= pwm-fsl-ftm.o
 obj-$(CONFIG_PWM_GPIO)		+= pwm-gpio.o
diff --git a/drivers/pwm/pwm-dwc-core.c b/drivers/pwm/pwm-dwc-core.c
index 6dabec93a3c6..ec90f75c840e 100644
--- a/drivers/pwm/pwm-dwc-core.c
+++ b/drivers/pwm/pwm-dwc-core.c
@@ -44,21 +44,47 @@ static int __dwc_pwm_configure_timer(struct dwc_pwm *dwc,
 	u32 high;
 	u32 low;
 
-	/*
-	 * Calculate width of low and high period in terms of input clock
-	 * periods and check are the result within HW limits between 1 and
-	 * 2^32 periods.
-	 */
-	tmp = DIV_ROUND_CLOSEST_ULL(state->duty_cycle, dwc->clk_ns);
-	if (tmp < 1 || tmp > (1ULL << 32))
-		return -ERANGE;
-	low = tmp - 1;
-
-	tmp = DIV_ROUND_CLOSEST_ULL(state->period - state->duty_cycle,
-				    dwc->clk_ns);
-	if (tmp < 1 || tmp > (1ULL << 32))
-		return -ERANGE;
-	high = tmp - 1;
+	if (dwc->pwm_0n100_enable) {
+		/*
+		 * Calculate width of low and high period in terms of input
+		 * clock periods and check are the result within HW limits
+		 * between 0 and 2^32 periods.
+		 */
+		tmp = DIV_ROUND_CLOSEST_ULL(state->duty_cycle, dwc->clk_ns);
+		if (tmp < 0 || tmp > (1UL << 32))
+			return -ERANGE;
+
+		if (pwm->args.polarity == PWM_POLARITY_INVERSED)
+			high = tmp;
+		else
+			low = tmp;
+
+		tmp = DIV_ROUND_CLOSEST_ULL(state->period - state->duty_cycle,
+					    dwc->clk_ns);
+		if (tmp < 0 || tmp > (1UL << 32))
+			return -ERANGE;
+
+		if (pwm->args.polarity == PWM_POLARITY_INVERSED)
+			low = tmp;
+		else
+			high = tmp;
+	} else {
+		/*
+		 * Calculate width of low and high period in terms of input
+		 * clock periods and check are the result within HW limits
+		 * between 1 and 2^32 periods.
+		 */
+		tmp = DIV_ROUND_CLOSEST_ULL(state->duty_cycle, dwc->clk_ns);
+		if (tmp < 1 || tmp > (1ULL << 32))
+			return -ERANGE;
+		low = tmp - 1;
+
+		tmp = DIV_ROUND_CLOSEST_ULL(state->period - state->duty_cycle,
+					    dwc->clk_ns);
+		if (tmp < 1 || tmp > (1ULL << 32))
+			return -ERANGE;
+		high = tmp - 1;
+	}
 
 	/*
 	 * Specification says timer usage flow is to disable timer, then
@@ -73,7 +99,8 @@ static int __dwc_pwm_configure_timer(struct dwc_pwm *dwc,
 	 * Write Load Count and Load Count 2 registers. Former defines the
 	 * width of low period and latter the width of high period in terms
 	 * multiple of input clock periods:
-	 * Width = ((Count + 1) * input clock period).
+	 * Width = ((Count + 1) * input clock period) or
+	 * Width = (Count * input clock period) : supported 0% and 100%).
 	 */
 	dwc_pwm_writel(dwc, low, DWC_TIM_LD_CNT(pwm->hwpwm));
 	dwc_pwm_writel(dwc, high, DWC_TIM_LD_CNT2(pwm->hwpwm));
@@ -85,6 +112,9 @@ static int __dwc_pwm_configure_timer(struct dwc_pwm *dwc,
 	 * periods are set by Load Count registers.
 	 */
 	ctrl = DWC_TIM_CTRL_MODE_USER | DWC_TIM_CTRL_PWM;
+	if (dwc->pwm_0n100_enable)
+		ctrl |= DWC_TIM_CTRL_0N100PWM_EN;
+
 	dwc_pwm_writel(dwc, ctrl, DWC_TIM_CTRL(pwm->hwpwm));
 
 	/*
@@ -137,9 +167,17 @@ static int dwc_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 	 * based on the timer load-count only.
 	 */
 	if (ctrl & DWC_TIM_CTRL_PWM) {
-		duty = (ld + 1) * dwc->clk_ns;
-		period = (ld2 + 1)  * dwc->clk_ns;
-		period += duty;
+		if (dwc->pwm_0n100_enable) {
+			if (pwm->args.polarity == PWM_POLARITY_INVERSED)
+				duty = ld2 * dwc->clk_ns;
+			else
+				duty = ld * dwc->clk_ns;
+			period = (ld + ld2) * dwc->clk_ns;
+		} else {
+			duty = (ld + 1) * dwc->clk_ns;
+			period = (ld2 + 1)  * dwc->clk_ns;
+			period += duty;
+		}
 	} else {
 		duty = (ld + 1) * dwc->clk_ns;
 		period = duty * 2;
diff --git a/drivers/pwm/pwm-dwc-eic7700.c b/drivers/pwm/pwm-dwc-eic7700.c
new file mode 100644
index 000000000000..1bbe5593934b
--- /dev/null
+++ b/drivers/pwm/pwm-dwc-eic7700.c
@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ESWIN PWM driver (Based on DesignWare PWM Controller driver)
+ *
+ * Copyright 2025, Beijing ESWIN Computing Technology Co., Ltd..
+ * All rights reserved.
+ *
+ * Authors:
+ *	Xiang Xu <xuxiang@eswincomputing.com>
+ *	Guosheng Wang <wangguosheng@eswincomputing.com>
+ *	Xuyang Dong <dongxuyang@eswincomputing.com>
+ *
+ * Characteristics:
+ * - The hardware can generate 0% and 100% duty cycle.
+ *   - 0% duty cycle (fully off)
+ *   - 100% duty cycle (fully on)
+ *
+ * Limitations:
+ * - The duty cycle and period cannot both be set to 0.
+ * - The controller hardware provides up to 3 PWM channels.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/pwm.h>
+#include <linux/reset.h>
+
+#include "pwm-dwc.h"
+
+#define DW_PWMS_TOTAL	3
+
+static int eic7700_pwm_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct dwc_pwm_drvdata *data;
+	struct pwm_chip *chip = NULL;
+	struct dwc_pwm *dwc = NULL;
+	int ret;
+
+	data = devm_kzalloc(dev, sizeof(data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	chip = dwc_pwm_alloc(dev);
+	if (IS_ERR(chip))
+		return dev_err_probe(dev, -ENOMEM, "failed to alloc pwm\n");
+
+	dwc = to_dwc_pwm(chip);
+
+	if (of_property_read_bool(dev->of_node, "snps,pwm-full-range-enable"))
+		dwc->pwm_0n100_enable = true;
+
+	dwc->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(dwc->base))
+		return dev_err_probe(dev, PTR_ERR(dwc->base),
+				     "failed to get base\n");
+
+	dwc->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(dwc->clk))
+		return dev_err_probe(dev, PTR_ERR(dwc->clk),
+				     "failed to get clock\n");
+
+	ret = clk_prepare_enable(dwc->clk);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to enable clock\n");
+
+	dwc->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(dwc->rst)) {
+		dev_err(dev, "failed to get reset control\n");
+		ret = PTR_ERR(dwc->rst);
+		goto err_clk_disable;
+	}
+
+	ret = reset_control_deassert(dwc->rst);
+	if (ret) {
+		dev_err(dev, "failed to deassert reset: %d\n", ret);
+		goto err_clk_disable;
+	}
+
+	ret = devm_pwmchip_add(dev, chip);
+	if (ret) {
+		dev_err(dev, "failed to add pwmchip: %d\n", ret);
+		goto err_reset_assert;
+	}
+
+	data->chips[0] = chip;
+	dev_set_drvdata(dev, data);
+
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+	pm_runtime_get_noresume(dev);
+
+	return 0;
+
+err_reset_assert:
+	reset_control_assert(dwc->rst);
+err_clk_disable:
+	clk_disable_unprepare(dwc->clk);
+
+	return ret;
+}
+
+static void eic7700_pwm_remove(struct platform_device *pdev)
+{
+	struct dwc_pwm_drvdata *data = platform_get_drvdata(pdev);
+	struct pwm_chip *chip = data->chips[0];
+	struct dwc_pwm *dwc = to_dwc_pwm(chip);
+	struct device *dev = &pdev->dev;
+
+	clk_disable_unprepare(dwc->clk);
+	reset_control_assert(dwc->rst);
+
+	pm_runtime_put_sync(dev);
+	pm_runtime_disable(dev);
+}
+
+static int eic7700_pwm_runtime_suspend(struct device *dev)
+{
+	struct dwc_pwm_drvdata *data = dev_get_drvdata(dev);
+	struct pwm_chip *chip = data->chips[0];
+	struct dwc_pwm *dwc = to_dwc_pwm(chip);
+	int idx, ret;
+
+	for (idx = 0; idx < DW_PWMS_TOTAL; idx++) {
+		if (chip->pwms[idx].state.enabled)
+			return -EBUSY;
+
+		dwc->ctx[idx].cnt = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT(idx));
+		dwc->ctx[idx].cnt2 = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT2(idx));
+		dwc->ctx[idx].ctrl = dwc_pwm_readl(dwc, DWC_TIM_CTRL(idx));
+	}
+
+	clk_disable_unprepare(dwc->clk);
+	ret = pinctrl_pm_select_sleep_state(dev);
+	if (ret) {
+		dev_err(dev, "failed to select sleep state: %d\n", ret);
+		clk_prepare_enable(dwc->clk);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int eic7700_pwm_runtime_resume(struct device *dev)
+{
+	struct dwc_pwm_drvdata *data = dev_get_drvdata(dev);
+	struct pwm_chip *chip = data->chips[0];
+	struct dwc_pwm *dwc = to_dwc_pwm(chip);
+	int idx, ret;
+
+	ret = pinctrl_pm_select_default_state(dev);
+	if (ret) {
+		dev_err(dev, "failed to select default state: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(dwc->clk);
+	if (ret) {
+		dev_err(dev, "failed to enable clock: %d\n", ret);
+		return ret;
+	}
+
+	for (idx = 0; idx < DW_PWMS_TOTAL; idx++) {
+		dwc_pwm_writel(dwc, dwc->ctx[idx].cnt, DWC_TIM_LD_CNT(idx));
+		dwc_pwm_writel(dwc, dwc->ctx[idx].cnt2, DWC_TIM_LD_CNT2(idx));
+		dwc_pwm_writel(dwc, dwc->ctx[idx].ctrl, DWC_TIM_CTRL(idx));
+	}
+
+	return 0;
+}
+
+static int eic7700_pwm_suspend(struct device *dev)
+{
+	int ret;
+
+	if (!pm_runtime_suspended(dev)) {
+		ret = eic7700_pwm_runtime_suspend(dev);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int eic7700_pwm_resume(struct device *dev)
+{
+	int ret;
+
+	if (!pm_runtime_suspended(dev)) {
+		ret = eic7700_pwm_runtime_resume(dev);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops eic7700_pwm_pm_ops = {
+	RUNTIME_PM_OPS(eic7700_pwm_runtime_suspend, eic7700_pwm_runtime_resume,
+		       NULL)
+	SYSTEM_SLEEP_PM_OPS(eic7700_pwm_suspend, eic7700_pwm_resume)
+};
+
+static const struct of_device_id eic7700_pwm_id_table[] = {
+	{ .compatible = "eswin,eic7700-pwm", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, eic7700_pwm_id_table);
+
+static struct platform_driver eic7700_pwm_driver = {
+	.probe = eic7700_pwm_probe,
+	.remove = eic7700_pwm_remove,
+	.driver = {
+		.name	= "eic7700-pwm",
+		.pm = pm_sleep_ptr(&eic7700_pwm_pm_ops),
+		.of_match_table = of_match_ptr(eic7700_pwm_id_table),
+	},
+};
+
+module_platform_driver(eic7700_pwm_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Xiang Xu <xuxiang@eswincomputing.com>");
+MODULE_AUTHOR("Guosheng Wang <wangguosheng@eswincomputing.com>");
+MODULE_AUTHOR("Xuyang Dong <dongxuyang@eswincomputing.com>");
+MODULE_DESCRIPTION("ESWIN EIC7700 PWM Controller");
diff --git a/drivers/pwm/pwm-dwc.h b/drivers/pwm/pwm-dwc.h
index 1562594e7f85..27d567e82ac0 100644
--- a/drivers/pwm/pwm-dwc.h
+++ b/drivers/pwm/pwm-dwc.h
@@ -26,12 +26,13 @@ MODULE_IMPORT_NS("dwc_pwm");
 #define DWC_TIMERS_TOTAL	8
 
 /* Timer Control Register */
-#define DWC_TIM_CTRL_EN		BIT(0)
-#define DWC_TIM_CTRL_MODE	BIT(1)
-#define DWC_TIM_CTRL_MODE_FREE	(0 << 1)
-#define DWC_TIM_CTRL_MODE_USER	(1 << 1)
-#define DWC_TIM_CTRL_INT_MASK	BIT(2)
-#define DWC_TIM_CTRL_PWM	BIT(3)
+#define DWC_TIM_CTRL_EN			BIT(0)
+#define DWC_TIM_CTRL_MODE		BIT(1)
+#define DWC_TIM_CTRL_MODE_FREE		(0 << 1)
+#define DWC_TIM_CTRL_MODE_USER		BIT(1)
+#define DWC_TIM_CTRL_INT_MASK		BIT(2)
+#define DWC_TIM_CTRL_PWM		BIT(3)
+#define DWC_TIM_CTRL_0N100PWM_EN	BIT(4)
 
 struct dwc_pwm_info {
 	unsigned int nr;
@@ -53,6 +54,9 @@ struct dwc_pwm_ctx {
 struct dwc_pwm {
 	void __iomem *base;
 	unsigned int clk_ns;
+	struct clk *clk;
+	struct reset_control *rst;
+	bool pwm_0n100_enable;
 	struct dwc_pwm_ctx ctx[DWC_TIMERS_TOTAL];
 };
 
-- 
2.34.1

Re: [PATCH 2/2] pwm: eswin: Add EIC7700 pwm driver

[kernel test robot]

Hi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on robh/for-next]
[also build test WARNING on linus/master v6.18 next-20251205]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/dongxuyang-eswincomputing-com/dt-bindings-pwm-eswin-Add-EIC7700-pwm-controller/20251205-171328
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
patch link:    https://lore.kernel.org/r/20251205090509.1501-1-dongxuyang%40eswincomputing.com
patch subject: [PATCH 2/2] pwm: eswin: Add EIC7700 pwm driver
config: m68k-allmodconfig (https://download.01.org/0day-ci/archive/20251206/202512061720.j31AsgM7-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 15.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251206/202512061720.j31AsgM7-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202512061720.j31AsgM7-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/pwm/pwm-dwc-core.c: In function '__dwc_pwm_configure_timer':
>> drivers/pwm/pwm-dwc-core.c:54:43: warning: left shift count >= width of type [-Wshift-count-overflow]
      54 |                 if (tmp < 0 || tmp > (1UL << 32))
         |                                           ^~
   drivers/pwm/pwm-dwc-core.c:64:43: warning: left shift count >= width of type [-Wshift-count-overflow]
      64 |                 if (tmp < 0 || tmp > (1UL << 32))
         |                                           ^~


vim +54 drivers/pwm/pwm-dwc-core.c

    37	
    38	static int __dwc_pwm_configure_timer(struct dwc_pwm *dwc,
    39					     struct pwm_device *pwm,
    40					     const struct pwm_state *state)
    41	{
    42		u64 tmp;
    43		u32 ctrl;
    44		u32 high;
    45		u32 low;
    46	
    47		if (dwc->pwm_0n100_enable) {
    48			/*
    49			 * Calculate width of low and high period in terms of input
    50			 * clock periods and check are the result within HW limits
    51			 * between 0 and 2^32 periods.
    52			 */
    53			tmp = DIV_ROUND_CLOSEST_ULL(state->duty_cycle, dwc->clk_ns);
  > 54			if (tmp < 0 || tmp > (1UL << 32))
    55				return -ERANGE;
    56	
    57			if (pwm->args.polarity == PWM_POLARITY_INVERSED)
    58				high = tmp;
    59			else
    60				low = tmp;
    61	
    62			tmp = DIV_ROUND_CLOSEST_ULL(state->period - state->duty_cycle,
    63						    dwc->clk_ns);
    64			if (tmp < 0 || tmp > (1UL << 32))
    65				return -ERANGE;
    66	
    67			if (pwm->args.polarity == PWM_POLARITY_INVERSED)
    68				low = tmp;
    69			else
    70				high = tmp;
    71		} else {
    72			/*
    73			 * Calculate width of low and high period in terms of input
    74			 * clock periods and check are the result within HW limits
    75			 * between 1 and 2^32 periods.
    76			 */
    77			tmp = DIV_ROUND_CLOSEST_ULL(state->duty_cycle, dwc->clk_ns);
    78			if (tmp < 1 || tmp > (1ULL << 32))
    79				return -ERANGE;
    80			low = tmp - 1;
    81	
    82			tmp = DIV_ROUND_CLOSEST_ULL(state->period - state->duty_cycle,
    83						    dwc->clk_ns);
    84			if (tmp < 1 || tmp > (1ULL << 32))
    85				return -ERANGE;
    86			high = tmp - 1;
    87		}
    88	
    89		/*
    90		 * Specification says timer usage flow is to disable timer, then
    91		 * program it followed by enable. It also says Load Count is loaded
    92		 * into timer after it is enabled - either after a disable or
    93		 * a reset. Based on measurements it happens also without disable
    94		 * whenever Load Count is updated. But follow the specification.
    95		 */
    96		__dwc_pwm_set_enable(dwc, pwm->hwpwm, false);
    97	
    98		/*
    99		 * Write Load Count and Load Count 2 registers. Former defines the
   100		 * width of low period and latter the width of high period in terms
   101		 * multiple of input clock periods:
   102		 * Width = ((Count + 1) * input clock period) or
   103		 * Width = (Count * input clock period) : supported 0% and 100%).
   104		 */
   105		dwc_pwm_writel(dwc, low, DWC_TIM_LD_CNT(pwm->hwpwm));
   106		dwc_pwm_writel(dwc, high, DWC_TIM_LD_CNT2(pwm->hwpwm));
   107	
   108		/*
   109		 * Set user-defined mode, timer reloads from Load Count registers
   110		 * when it counts down to 0.
   111		 * Set PWM mode, it makes output to toggle and width of low and high
   112		 * periods are set by Load Count registers.
   113		 */
   114		ctrl = DWC_TIM_CTRL_MODE_USER | DWC_TIM_CTRL_PWM;
   115		if (dwc->pwm_0n100_enable)
   116			ctrl |= DWC_TIM_CTRL_0N100PWM_EN;
   117	
   118		dwc_pwm_writel(dwc, ctrl, DWC_TIM_CTRL(pwm->hwpwm));
   119	
   120		/*
   121		 * Enable timer. Output starts from low period.
   122		 */
   123		__dwc_pwm_set_enable(dwc, pwm->hwpwm, state->enabled);
   124	
   125		return 0;
   126	}
   127	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 2/2] pwm: eswin: Add EIC7700 pwm driver

[Krzysztof Kozlowski]

On Fri, Dec 05, 2025 at 05:05:09PM +0800, dongxuyang@eswincomputing.com wrote:
 + *
> + * Limitations:
> + * - The duty cycle and period cannot both be set to 0.
> + * - The controller hardware provides up to 3 PWM channels.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/io.h>

Where do you use half of above headers?

> +#include <linux/pinctrl/consumer.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/pwm.h>
> +#include <linux/reset.h>
> +
> +#include "pwm-dwc.h"
> +
> +#define DW_PWMS_TOTAL	3
> +
> +static int eic7700_pwm_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct dwc_pwm_drvdata *data;
> +	struct pwm_chip *chip = NULL;
> +	struct dwc_pwm *dwc = NULL;
> +	int ret;
> +
> +	data = devm_kzalloc(dev, sizeof(data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	chip = dwc_pwm_alloc(dev);
> +	if (IS_ERR(chip))
> +		return dev_err_probe(dev, -ENOMEM, "failed to alloc pwm\n");
> +
> +	dwc = to_dwc_pwm(chip);
> +
> +	if (of_property_read_bool(dev->of_node, "snps,pwm-full-range-enable"))
> +		dwc->pwm_0n100_enable = true;
> +
> +	dwc->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(dwc->base))
> +		return dev_err_probe(dev, PTR_ERR(dwc->base),
> +				     "failed to get base\n");
> +
> +	dwc->clk = devm_clk_get(dev, NULL);

Just use the enabled varian and drop below prepare enable call.

> +	if (IS_ERR(dwc->clk))
> +		return dev_err_probe(dev, PTR_ERR(dwc->clk),
> +				     "failed to get clock\n");
> +
> +	ret = clk_prepare_enable(dwc->clk);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "failed to enable clock\n");
> +
> +	dwc->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
> +	if (IS_ERR(dwc->rst)) {
> +		dev_err(dev, "failed to get reset control\n");
> +		ret = PTR_ERR(dwc->rst);
> +		goto err_clk_disable;
> +	}
> +
> +	ret = reset_control_deassert(dwc->rst);
> +	if (ret) {
> +		dev_err(dev, "failed to deassert reset: %d\n", ret);
> +		goto err_clk_disable;
> +	}
> +
> +	ret = devm_pwmchip_add(dev, chip);
> +	if (ret) {
> +		dev_err(dev, "failed to add pwmchip: %d\n", ret);
> +		goto err_reset_assert;
> +	}
> +
> +	data->chips[0] = chip;
> +	dev_set_drvdata(dev, data);
> +
> +	pm_runtime_set_active(dev);
> +	pm_runtime_enable(dev);
> +	pm_runtime_get_noresume(dev);
> +
> +	return 0;
> +
> +err_reset_assert:
> +	reset_control_assert(dwc->rst);
> +err_clk_disable:
> +	clk_disable_unprepare(dwc->clk);
> +
> +	return ret;
> +}
> +
> +static void eic7700_pwm_remove(struct platform_device *pdev)
> +{
> +	struct dwc_pwm_drvdata *data = platform_get_drvdata(pdev);
> +	struct pwm_chip *chip = data->chips[0];
> +	struct dwc_pwm *dwc = to_dwc_pwm(chip);
> +	struct device *dev = &pdev->dev;
> +
> +	clk_disable_unprepare(dwc->clk);
> +	reset_control_assert(dwc->rst);
> +
> +	pm_runtime_put_sync(dev);
> +	pm_runtime_disable(dev);
> +}
> +
> +static int eic7700_pwm_runtime_suspend(struct device *dev)
> +{
> +	struct dwc_pwm_drvdata *data = dev_get_drvdata(dev);
> +	struct pwm_chip *chip = data->chips[0];
> +	struct dwc_pwm *dwc = to_dwc_pwm(chip);
> +	int idx, ret;
> +
> +	for (idx = 0; idx < DW_PWMS_TOTAL; idx++) {
> +		if (chip->pwms[idx].state.enabled)
> +			return -EBUSY;
> +
> +		dwc->ctx[idx].cnt = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT(idx));
> +		dwc->ctx[idx].cnt2 = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT2(idx));
> +		dwc->ctx[idx].ctrl = dwc_pwm_readl(dwc, DWC_TIM_CTRL(idx));
> +	}
> +
> +	clk_disable_unprepare(dwc->clk);
> +	ret = pinctrl_pm_select_sleep_state(dev);
> +	if (ret) {
> +		dev_err(dev, "failed to select sleep state: %d\n", ret);
> +		clk_prepare_enable(dwc->clk);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int eic7700_pwm_runtime_resume(struct device *dev)
> +{
> +	struct dwc_pwm_drvdata *data = dev_get_drvdata(dev);
> +	struct pwm_chip *chip = data->chips[0];
> +	struct dwc_pwm *dwc = to_dwc_pwm(chip);
> +	int idx, ret;
> +
> +	ret = pinctrl_pm_select_default_state(dev);
> +	if (ret) {
> +		dev_err(dev, "failed to select default state: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = clk_prepare_enable(dwc->clk);
> +	if (ret) {
> +		dev_err(dev, "failed to enable clock: %d\n", ret);
> +		return ret;
> +	}
> +
> +	for (idx = 0; idx < DW_PWMS_TOTAL; idx++) {
> +		dwc_pwm_writel(dwc, dwc->ctx[idx].cnt, DWC_TIM_LD_CNT(idx));
> +		dwc_pwm_writel(dwc, dwc->ctx[idx].cnt2, DWC_TIM_LD_CNT2(idx));
> +		dwc_pwm_writel(dwc, dwc->ctx[idx].ctrl, DWC_TIM_CTRL(idx));
> +	}
> +
> +	return 0;
> +}
> +
> +static int eic7700_pwm_suspend(struct device *dev)
> +{
> +	int ret;
> +
> +	if (!pm_runtime_suspended(dev)) {
> +		ret = eic7700_pwm_runtime_suspend(dev);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int eic7700_pwm_resume(struct device *dev)
> +{
> +	int ret;
> +
> +	if (!pm_runtime_suspended(dev)) {
> +		ret = eic7700_pwm_runtime_resume(dev);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops eic7700_pwm_pm_ops = {
> +	RUNTIME_PM_OPS(eic7700_pwm_runtime_suspend, eic7700_pwm_runtime_resume,
> +		       NULL)
> +	SYSTEM_SLEEP_PM_OPS(eic7700_pwm_suspend, eic7700_pwm_resume)
> +};
> +
> +static const struct of_device_id eic7700_pwm_id_table[] = {
> +	{ .compatible = "eswin,eic7700-pwm", },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, eic7700_pwm_id_table);
> +
> +static struct platform_driver eic7700_pwm_driver = {
> +	.probe = eic7700_pwm_probe,
> +	.remove = eic7700_pwm_remove,
> +	.driver = {
> +		.name	= "eic7700-pwm",
> +		.pm = pm_sleep_ptr(&eic7700_pwm_pm_ops),
> +		.of_match_table = of_match_ptr(eic7700_pwm_id_table),

Drop of_match_ptr, you have warning here. Look at other drivers how they
do it.

Best regards,
Krzysztof