[PATCH v2 1/6] dt-bindings: hwmon: add Microchip LAN969x fan controller

[PATCH v2 1/6] dt-bindings: hwmon: add Microchip LAN969x fan controller

[Robert Marko]

The LAN969x fan controller has a PWM output and tachometer input in a
register block separate from the Sparx5-compatible temperature sensor.
Describe it with its own compatible and binding.

The optional fan child specifies PWM period and polarity, tachometer
pulses per revolution, and thermal cooling levels.

Signed-off-by: Robert Marko <robert.marko@sartura.hr>
---
Changes in v2:
- Describe the fan controller in a separate binding and compatible.
- Keep the existing temperature-sensor binding unchanged.

 .../bindings/hwmon/microchip,lan9691-fan.yaml | 83 +++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/microchip,lan9691-fan.yaml

diff --git a/Documentation/devicetree/bindings/hwmon/microchip,lan9691-fan.yaml b/Documentation/devicetree/bindings/hwmon/microchip,lan9691-fan.yaml
new file mode 100644
index 0000000000000..0b7d38a6d20ae
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/microchip,lan9691-fan.yaml
@@ -0,0 +1,83 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/microchip,lan9691-fan.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip LAN969x Fan Controller
+
+maintainers:
+  - Robert Marko <robert.marko@sartura.hr>
+
+description: |
+  LAN969x fan controller with a PWM output and tachometer input. The fan
+  child's pwms property references this node to specify the PWM period and
+  polarity.
+
+properties:
+  compatible:
+    const: microchip,lan9691-fan
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: System reference clock
+
+  '#pwm-cells':
+    const: 2
+    description: |
+      Number of cells in a PWM specifier.
+      - cell 0: PWM period in nanoseconds
+      - cell 1: PWM polarity: 0 or PWM_POLARITY_INVERTED
+
+  fan:
+    $ref: fan-common.yaml#
+    unevaluatedProperties: false
+
+    properties:
+      cooling-levels:
+        description:
+          PWM duty-cycle values corresponding to thermal cooling states.
+        items:
+          maximum: 255
+
+      pulses-per-revolution:
+        minimum: 1
+        maximum: 4
+        default: 2
+
+    required:
+      - pwms
+
+    dependencies:
+      '#cooling-cells':
+        - cooling-levels
+      cooling-levels:
+        - '#cooling-cells'
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - '#pwm-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/pwm/pwm.h>
+
+    fanctrl: fan-controller@e2010348 {
+        compatible = "microchip,lan9691-fan";
+        reg = <0xe2010348 0xc>;
+        clocks = <&sys_clk>;
+        #pwm-cells = <2>;
+
+        fan {
+            pwms = <&fanctrl 40000 PWM_POLARITY_INVERTED>;
+            cooling-levels = <0 128 192 255>;
+            #cooling-cells = <2>;
+        };
+    };
-- 
2.56.0

[PATCH v2 2/6] hwmon: sparx5: separate temperature reading from sensor dispatch

[Robert Marko]

Move temperature conversion into a helper and dispatch reads by sensor
type. Preserve the existing temperature calculation and error handling
in preparation for adding fan monitoring.

Signed-off-by: Robert Marko <robert.marko@sartura.hr>
---
Changes in v2:
- No changes.

 drivers/hwmon/sparx5-temp.c | 54 +++++++++++++++++++++----------------
 1 file changed, 31 insertions(+), 23 deletions(-)

diff --git a/drivers/hwmon/sparx5-temp.c b/drivers/hwmon/sparx5-temp.c
index aa91780737446..0fd5c147f8167 100644
--- a/drivers/hwmon/sparx5-temp.c
+++ b/drivers/hwmon/sparx5-temp.c
@@ -37,38 +37,46 @@ static void s5_temp_enable(struct s5_hwmon *hwmon)
 	writel(val, hwmon->base + TEMP_CFG);
 }
 
+static int s5_read_temp(struct s5_hwmon *hwmon, long *temp)
+{
+	int value;
+	u32 stat;
+
+	stat = readl_relaxed(hwmon->base + TEMP_STAT);
+	if (!(stat & TEMP_STAT_VALID))
+		return -EAGAIN;
+	value = stat & TEMP_STAT_TEMP;
+	/*
+	 * From register documentation:
+	 * Temp(C) = TEMP_SENSOR_STAT.TEMP / 4096 * 352.2 - 109.4
+	 */
+	value = DIV_ROUND_CLOSEST(value * 3522, 4096) - 1094;
+	/*
+	 * Scale down by 10 from above and multiply by 1000 to
+	 * have millidegrees as specified by the hwmon sysfs
+	 * interface.
+	 */
+	value *= 100;
+	*temp = value;
+
+	return 0;
+}
+
 static int s5_read(struct device *dev, enum hwmon_sensor_types type,
-		   u32 attr, int channel, long *temp)
+		   u32 attr, int channel, long *val)
 {
 	struct s5_hwmon *hwmon = dev_get_drvdata(dev);
-	int rc = 0, value;
-	u32 stat;
 
-	switch (attr) {
-	case hwmon_temp_input:
-		stat = readl_relaxed(hwmon->base + TEMP_STAT);
-		if (!(stat & TEMP_STAT_VALID))
-			return -EAGAIN;
-		value = stat & TEMP_STAT_TEMP;
-		/*
-		 * From register documentation:
-		 * Temp(C) = TEMP_SENSOR_STAT.TEMP / 4096 * 352.2 - 109.4
-		 */
-		value = DIV_ROUND_CLOSEST(value * 3522, 4096) - 1094;
-		/*
-		 * Scale down by 10 from above and multiply by 1000 to
-		 * have millidegrees as specified by the hwmon sysfs
-		 * interface.
-		 */
-		value *= 100;
-		*temp = value;
+	switch (type) {
+	case hwmon_temp:
+		if (attr == hwmon_temp_input)
+			return s5_read_temp(hwmon, val);
 		break;
 	default:
-		rc = -EOPNOTSUPP;
 		break;
 	}
 
-	return rc;
+	return -EOPNOTSUPP;
 }
 
 static umode_t s5_is_visible(const void *_data, enum hwmon_sensor_types type,
-- 
2.56.0

[PATCH v2 3/6] hwmon: sparx5: add LAN969x fan monitoring support

[Robert Marko]

LAN969x has a fan controller with a tachometer in a register block
separate from its Sparx5-compatible temperature sensor. Match the fan
node independently and expose fan1_input on its own hwmon device.

Read the optional pulses-per-revolution property from the fan child.
Preserve the temperature-only behavior of existing device trees.

Signed-off-by: Robert Marko <robert.marko@sartura.hr>
---
Changes in v2:
- Register fan and temperature monitoring as separate hwmon devices.
- Reject a present but malformed pulses-per-revolution property.

 Documentation/hwmon/sparx5-temp.rst |   9 ++
 drivers/hwmon/Kconfig               |   7 +-
 drivers/hwmon/sparx5-temp.c         | 146 ++++++++++++++++++++++++----
 3 files changed, 139 insertions(+), 23 deletions(-)

diff --git a/Documentation/hwmon/sparx5-temp.rst b/Documentation/hwmon/sparx5-temp.rst
index 0140809089542..a053d12fbdbbb 100644
--- a/Documentation/hwmon/sparx5-temp.rst
+++ b/Documentation/hwmon/sparx5-temp.rst
@@ -15,6 +15,10 @@ Supported chips:
 
 Author: Lars Povlsen <lars.povlsen@microchip.com>
 
+The driver also supports the Microchip LAN969x temperature sensor and fan
+controller as separate devices. The fan controller uses the
+microchip,lan9691-fan compatible.
+
 Description
 -----------
 
@@ -30,4 +34,9 @@ The following attributes are supported.
 
 ======================= ========================================================
 temp1_input		Die temperature (in millidegree Celsius.)
+fan1_input              Fan speed in RPM (LAN969x only).
 ======================= ========================================================
+
+The tachometer counts pulses over one-second intervals, independently of the
+PWM output. The fan child's pulses-per-revolution property specifies how many
+pulses represent one revolution; it defaults to two.
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 3ae676a56d95c..deb9eb82b8501 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -669,11 +669,12 @@ config SENSORS_I5K_AMB
 	  will be called i5k_amb.
 
 config SENSORS_SPARX5
-	tristate "Sparx5 SoC temperature sensor"
+	tristate "Sparx5 and LAN969x SoC hardware monitoring"
 	depends on ARCH_SPARX5 || ARCH_LAN969X || COMPILE_TEST
 	help
-	  If you say yes here you get support for temperature monitoring
-	  with the Microchip Sparx5 SoC.
+	  If you say yes here you get support for temperature monitoring on
+	  Microchip Sparx5 and LAN969x SoCs, as well as fan monitoring on
+	  LAN969x SoCs.
 
 	  This driver can also be built as a module. If so, the module
 	  will be called sparx5-temp.
diff --git a/drivers/hwmon/sparx5-temp.c b/drivers/hwmon/sparx5-temp.c
index 0fd5c147f8167..1f197004780cc 100644
--- a/drivers/hwmon/sparx5-temp.c
+++ b/drivers/hwmon/sparx5-temp.c
@@ -9,8 +9,11 @@
 #include <linux/hwmon.h>
 #include <linux/init.h>
 #include <linux/io.h>
+#include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/property.h>
 
 #define TEMP_CTRL		0
 #define TEMP_CFG		4
@@ -20,9 +23,26 @@
 #define  TEMP_STAT_VALID	BIT(12)
 #define  TEMP_STAT_TEMP		GENMASK(11, 0)
 
+#define FAN_CFG			0
+#define  FAN_CFG_GATE_ENA	BIT(2)
+#define  FAN_CFG_STAT_MODE	BIT(0)
+#define FAN_PWM_FREQ		4
+#define  FAN_PWM_FREQ_CYCLES	GENMASK(27, 16)
+#define FAN_CNT			8
+#define  FAN_CNT_DATA		GENMASK(15, 0)
+
+#define FAN_TACH_INTERVAL_HZ	100000
+
+struct s5_match_data {
+	bool is_fan;
+};
+
 struct s5_hwmon {
 	void __iomem *base;
+	void __iomem *fan;
 	struct clk *clk;
+	unsigned long clk_rate;
+	u32 pulses_per_revolution;
 };
 
 static void s5_temp_enable(struct s5_hwmon *hwmon)
@@ -37,6 +57,24 @@ static void s5_temp_enable(struct s5_hwmon *hwmon)
 	writel(val, hwmon->base + TEMP_CFG);
 }
 
+static void s5_fan_enable(struct s5_hwmon *hwmon)
+{
+	u32 cycles, val;
+
+	cycles = DIV_ROUND_CLOSEST(hwmon->clk_rate, FAN_TACH_INTERVAL_HZ);
+	cycles = clamp_val(cycles, 1, FIELD_MAX(FAN_PWM_FREQ_CYCLES));
+
+	val = readl(hwmon->fan + FAN_PWM_FREQ);
+	val &= ~FAN_PWM_FREQ_CYCLES;
+	val |= FIELD_PREP(FAN_PWM_FREQ_CYCLES, cycles);
+	writel(val, hwmon->fan + FAN_PWM_FREQ);
+
+	/* Count all tachometer pulses over one-second intervals. */
+	val = readl(hwmon->fan + FAN_CFG);
+	val &= ~(FAN_CFG_STAT_MODE | FAN_CFG_GATE_ENA);
+	writel(val, hwmon->fan + FAN_CFG);
+}
+
 static int s5_read_temp(struct s5_hwmon *hwmon, long *temp)
 {
 	int value;
@@ -62,6 +100,17 @@ static int s5_read_temp(struct s5_hwmon *hwmon, long *temp)
 	return 0;
 }
 
+static int s5_read_fan(struct s5_hwmon *hwmon, long *val)
+{
+	u32 count;
+
+	count = readl_relaxed(hwmon->fan + FAN_CNT);
+	count = FIELD_GET(FAN_CNT_DATA, count);
+	*val = count * 60 / hwmon->pulses_per_revolution;
+
+	return 0;
+}
+
 static int s5_read(struct device *dev, enum hwmon_sensor_types type,
 		   u32 attr, int channel, long *val)
 {
@@ -72,6 +121,10 @@ static int s5_read(struct device *dev, enum hwmon_sensor_types type,
 		if (attr == hwmon_temp_input)
 			return s5_read_temp(hwmon, val);
 		break;
+	case hwmon_fan:
+		if (attr == hwmon_fan_input && hwmon->fan)
+			return s5_read_fan(hwmon, val);
+		break;
 	default:
 		break;
 	}
@@ -82,62 +135,115 @@ static int s5_read(struct device *dev, enum hwmon_sensor_types type,
 static umode_t s5_is_visible(const void *_data, enum hwmon_sensor_types type,
 			     u32 attr, int channel)
 {
-	if (type != hwmon_temp)
-		return 0;
+	const struct s5_hwmon *hwmon = _data;
 
-	switch (attr) {
-	case hwmon_temp_input:
-		return 0444;
+	switch (type) {
+	case hwmon_temp:
+		return attr == hwmon_temp_input ? 0444 : 0;
+	case hwmon_fan:
+		if (hwmon->fan && attr == hwmon_fan_input)
+			return 0444;
+		return 0;
 	default:
 		return 0;
 	}
 }
 
-static const struct hwmon_channel_info * const s5_info[] = {
+static const struct hwmon_channel_info * const s5_temp_info[] = {
 	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
 	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
 	NULL
 };
 
+static const struct hwmon_channel_info * const s5_fan_info[] = {
+	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT),
+	NULL
+};
+
 static const struct hwmon_ops s5_hwmon_ops = {
 	.is_visible = s5_is_visible,
 	.read = s5_read,
 };
 
-static const struct hwmon_chip_info s5_chip_info = {
+static const struct hwmon_chip_info s5_temp_chip_info = {
 	.ops = &s5_hwmon_ops,
-	.info = s5_info,
+	.info = s5_temp_info,
+};
+
+static const struct hwmon_chip_info s5_fan_chip_info = {
+	.ops = &s5_hwmon_ops,
+	.info = s5_fan_info,
 };
 
 static int s5_temp_probe(struct platform_device *pdev)
 {
+	const struct s5_match_data *match_data;
+	struct device *dev = &pdev->dev;
 	struct device *hwmon_dev;
 	struct s5_hwmon *hwmon;
+	struct device_node *fan_np __free(device_node) = NULL;
+	void __iomem *base;
+	bool is_fan;
+	int ret;
 
-	hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL);
+	match_data = device_get_match_data(dev);
+	is_fan = match_data && match_data->is_fan;
+
+	hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
 	if (!hwmon)
 		return -ENOMEM;
 
-	hwmon->base = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(hwmon->base))
-		return PTR_ERR(hwmon->base);
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	if (is_fan) {
+		hwmon->fan = base;
+		hwmon->pulses_per_revolution = 2;
+		fan_np = of_get_available_child_by_name(dev->of_node, "fan");
+		if (fan_np &&
+		    of_property_present(fan_np, "pulses-per-revolution")) {
+			ret = of_property_read_u32(fan_np, "pulses-per-revolution",
+						   &hwmon->pulses_per_revolution);
+			if (ret)
+				return dev_err_probe(dev, ret,
+						     "invalid pulses-per-revolution\n");
+		}
+		if (!hwmon->pulses_per_revolution ||
+		    hwmon->pulses_per_revolution > 4)
+			return dev_err_probe(dev, -EINVAL,
+					     "invalid pulses-per-revolution\n");
+	} else {
+		hwmon->base = base;
+	}
 
-	hwmon->clk = devm_clk_get_enabled(&pdev->dev, NULL);
+	hwmon->clk = devm_clk_get_enabled(dev, NULL);
 	if (IS_ERR(hwmon->clk))
 		return PTR_ERR(hwmon->clk);
+	hwmon->clk_rate = clk_get_rate(hwmon->clk);
 
-	s5_temp_enable(hwmon);
+	if (is_fan)
+		s5_fan_enable(hwmon);
+	else
+		s5_temp_enable(hwmon);
 
-	hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
-							 "s5_temp",
-							 hwmon,
-							 &s5_chip_info,
-							 NULL);
+	hwmon_dev = devm_hwmon_device_register_with_info(dev,
+					is_fan ? "lan969x_fan" : "s5_temp", hwmon,
+					is_fan ? &s5_fan_chip_info :
+						 &s5_temp_chip_info, NULL);
 
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }
 
+static const struct s5_match_data lan969x_fan_match_data = {
+	.is_fan = true,
+};
+
 static const struct of_device_id s5_temp_match[] = {
+	{
+		.compatible = "microchip,lan9691-fan",
+		.data = &lan969x_fan_match_data,
+	},
 	{ .compatible = "microchip,sparx5-temp" },
 	{},
 };
@@ -154,5 +260,5 @@ static struct platform_driver s5_temp_driver = {
 module_platform_driver(s5_temp_driver);
 
 MODULE_AUTHOR("Lars Povlsen <lars.povlsen@microchip.com>");
-MODULE_DESCRIPTION("Sparx5 SoC temperature sensor driver");
+MODULE_DESCRIPTION("Sparx5 SoC hardware monitoring driver");
 MODULE_LICENSE("GPL");
-- 
2.56.0

[PATCH v2 4/6] hwmon: sparx5: add LAN969x PWM support

[Robert Marko]

The LAN969x fan controller provides an 8-bit PWM output with a
programmable frequency and polarity.

Expose pwm1 and pwm1_freq on the fan hwmon device. Parse the fan child
node's standard PWM specifier and use its period and polarity flags to
configure the hardware.

Signed-off-by: Robert Marko <robert.marko@sartura.hr>
---
Changes in v2:
- Drop the private mutex; hwmon serializes sysfs accesses.
- Preserve firmware PWM polarity when no fan child is present.
- Convert the DT period directly to a divider and reject invalid values
  before changing fan registers.

 Documentation/hwmon/sparx5-temp.rst |   9 ++
 drivers/hwmon/Kconfig               |   2 +-
 drivers/hwmon/sparx5-temp.c         | 198 ++++++++++++++++++++++++++--
 3 files changed, 196 insertions(+), 13 deletions(-)

diff --git a/Documentation/hwmon/sparx5-temp.rst b/Documentation/hwmon/sparx5-temp.rst
index a053d12fbdbbb..edb12f890172c 100644
--- a/Documentation/hwmon/sparx5-temp.rst
+++ b/Documentation/hwmon/sparx5-temp.rst
@@ -35,8 +35,17 @@ The following attributes are supported.
 ======================= ========================================================
 temp1_input		Die temperature (in millidegree Celsius.)
 fan1_input              Fan speed in RPM (LAN969x only).
+pwm1                    PWM duty cycle, from 0 to 255 (LAN969x only).
+pwm1_freq               PWM frequency in Hz (LAN969x only).
 ======================= ========================================================
 
 The tachometer counts pulses over one-second intervals, independently of the
 PWM output. The fan child's pulses-per-revolution property specifies how many
 pulses represent one revolution; it defaults to two.
+
+On LAN969x, the fan child's pwms property selects the initial PWM period and
+polarity. The output is dedicated to this fan and is not available to external
+PWM consumers. The pwm1 value describes the logical duty cycle independently
+of the output polarity. Frequency requests are rounded to the nearest
+hardware divider value; requests outside the divider range are rejected.
+pwm1_freq reports the resulting frequency.
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index deb9eb82b8501..b77112518ebe6 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -673,7 +673,7 @@ config SENSORS_SPARX5
 	depends on ARCH_SPARX5 || ARCH_LAN969X || COMPILE_TEST
 	help
 	  If you say yes here you get support for temperature monitoring on
-	  Microchip Sparx5 and LAN969x SoCs, as well as fan monitoring on
+	  Microchip Sparx5 and LAN969x SoCs, as well as the fan controller on
 	  LAN969x SoCs.
 
 	  This driver can also be built as a module. If so, the module
diff --git a/drivers/hwmon/sparx5-temp.c b/drivers/hwmon/sparx5-temp.c
index 1f197004780cc..bdf08931f5b93 100644
--- a/drivers/hwmon/sparx5-temp.c
+++ b/drivers/hwmon/sparx5-temp.c
@@ -15,6 +15,8 @@
 #include <linux/platform_device.h>
 #include <linux/property.h>
 
+#include <dt-bindings/pwm/pwm.h>
+
 #define TEMP_CTRL		0
 #define TEMP_CFG		4
 #define  TEMP_CFG_CYCLES	GENMASK(24, 15)
@@ -24,14 +26,18 @@
 #define  TEMP_STAT_TEMP		GENMASK(11, 0)
 
 #define FAN_CFG			0
+#define  FAN_CFG_DUTY_CYCLE	GENMASK(23, 16)
+#define  FAN_CFG_INV_POL	BIT(3)
 #define  FAN_CFG_GATE_ENA	BIT(2)
 #define  FAN_CFG_STAT_MODE	BIT(0)
 #define FAN_PWM_FREQ		4
 #define  FAN_PWM_FREQ_CYCLES	GENMASK(27, 16)
+#define  FAN_PWM_FREQ_DIV	GENMASK(15, 0)
 #define FAN_CNT			8
 #define  FAN_CNT_DATA		GENMASK(15, 0)
 
 #define FAN_TACH_INTERVAL_HZ	100000
+#define FAN_PWM_FREQ_SCALE	256
 
 struct s5_match_data {
 	bool is_fan;
@@ -43,6 +49,8 @@ struct s5_hwmon {
 	struct clk *clk;
 	unsigned long clk_rate;
 	u32 pulses_per_revolution;
+	u32 pwm_period;
+	bool pwm_inverted;
 };
 
 static void s5_temp_enable(struct s5_hwmon *hwmon)
@@ -72,6 +80,11 @@ static void s5_fan_enable(struct s5_hwmon *hwmon)
 	/* Count all tachometer pulses over one-second intervals. */
 	val = readl(hwmon->fan + FAN_CFG);
 	val &= ~(FAN_CFG_STAT_MODE | FAN_CFG_GATE_ENA);
+	if (hwmon->pwm_period) {
+		val &= ~FAN_CFG_INV_POL;
+		if (hwmon->pwm_inverted)
+			val |= FAN_CFG_INV_POL;
+	}
 	writel(val, hwmon->fan + FAN_CFG);
 }
 
@@ -111,6 +124,32 @@ static int s5_read_fan(struct s5_hwmon *hwmon, long *val)
 	return 0;
 }
 
+static int s5_read_pwm(struct s5_hwmon *hwmon, long *val)
+{
+	u32 data;
+
+	data = readl_relaxed(hwmon->fan + FAN_CFG);
+	*val = FIELD_GET(FAN_CFG_DUTY_CYCLE, data);
+
+	return 0;
+}
+
+static int s5_read_pwm_freq(struct s5_hwmon *hwmon, long *val)
+{
+	unsigned long rate;
+	u32 divider;
+
+	divider = readl_relaxed(hwmon->fan + FAN_PWM_FREQ);
+	divider = FIELD_GET(FAN_PWM_FREQ_DIV, divider);
+	if (!divider)
+		return -ENODATA;
+
+	rate = DIV_ROUND_CLOSEST(hwmon->clk_rate, FAN_PWM_FREQ_SCALE);
+	*val = DIV_ROUND_CLOSEST(rate, divider);
+
+	return 0;
+}
+
 static int s5_read(struct device *dev, enum hwmon_sensor_types type,
 		   u32 attr, int channel, long *val)
 {
@@ -125,6 +164,18 @@ static int s5_read(struct device *dev, enum hwmon_sensor_types type,
 		if (attr == hwmon_fan_input && hwmon->fan)
 			return s5_read_fan(hwmon, val);
 		break;
+	case hwmon_pwm:
+		if (!hwmon->fan)
+			break;
+		switch (attr) {
+		case hwmon_pwm_input:
+			return s5_read_pwm(hwmon, val);
+		case hwmon_pwm_freq:
+			return s5_read_pwm_freq(hwmon, val);
+		default:
+			break;
+		}
+		break;
 	default:
 		break;
 	}
@@ -132,6 +183,85 @@ static int s5_read(struct device *dev, enum hwmon_sensor_types type,
 	return -EOPNOTSUPP;
 }
 
+static int s5_write_pwm(struct s5_hwmon *hwmon, long val)
+{
+	u32 data;
+
+	if (val < 0 || val > 255)
+		return -EINVAL;
+
+	data = readl_relaxed(hwmon->fan + FAN_CFG);
+	data &= ~FAN_CFG_DUTY_CYCLE;
+	data |= FIELD_PREP(FAN_CFG_DUTY_CYCLE, val);
+	writel_relaxed(data, hwmon->fan + FAN_CFG);
+
+	return 0;
+}
+
+static void s5_write_pwm_divider(struct s5_hwmon *hwmon, u32 divider)
+{
+	u32 data;
+
+	data = readl_relaxed(hwmon->fan + FAN_PWM_FREQ);
+	data &= ~FAN_PWM_FREQ_DIV;
+	data |= FIELD_PREP(FAN_PWM_FREQ_DIV, divider);
+	writel_relaxed(data, hwmon->fan + FAN_PWM_FREQ);
+}
+
+static int s5_write_pwm_period(struct s5_hwmon *hwmon)
+{
+	unsigned long rate;
+	u64 divider;
+
+	rate = DIV_ROUND_CLOSEST(hwmon->clk_rate, FAN_PWM_FREQ_SCALE);
+	divider = DIV_ROUND_CLOSEST_ULL((u64)rate * hwmon->pwm_period,
+					NSEC_PER_SEC);
+	if (!divider || divider > FIELD_MAX(FAN_PWM_FREQ_DIV))
+		return -ERANGE;
+
+	s5_write_pwm_divider(hwmon, divider);
+
+	return 0;
+}
+
+static int s5_write_pwm_freq(struct s5_hwmon *hwmon, long val)
+{
+	unsigned long rate, divider;
+
+	if (val <= 0)
+		return -EINVAL;
+
+	rate = DIV_ROUND_CLOSEST(hwmon->clk_rate, FAN_PWM_FREQ_SCALE);
+	if (val < DIV_ROUND_CLOSEST(rate, FIELD_MAX(FAN_PWM_FREQ_DIV)) ||
+	    val > rate)
+		return -ERANGE;
+
+	divider = DIV_ROUND_CLOSEST(rate, val);
+	divider = min_t(unsigned long, divider, FIELD_MAX(FAN_PWM_FREQ_DIV));
+
+	s5_write_pwm_divider(hwmon, divider);
+
+	return 0;
+}
+
+static int s5_write(struct device *dev, enum hwmon_sensor_types type,
+		    u32 attr, int channel, long val)
+{
+	struct s5_hwmon *hwmon = dev_get_drvdata(dev);
+
+	if (type != hwmon_pwm || !hwmon->fan)
+		return -EOPNOTSUPP;
+
+	switch (attr) {
+	case hwmon_pwm_input:
+		return s5_write_pwm(hwmon, val);
+	case hwmon_pwm_freq:
+		return s5_write_pwm_freq(hwmon, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 static umode_t s5_is_visible(const void *_data, enum hwmon_sensor_types type,
 			     u32 attr, int channel)
 {
@@ -144,6 +274,12 @@ static umode_t s5_is_visible(const void *_data, enum hwmon_sensor_types type,
 		if (hwmon->fan && attr == hwmon_fan_input)
 			return 0444;
 		return 0;
+	case hwmon_pwm:
+		if (!hwmon->fan)
+			return 0;
+		if (attr == hwmon_pwm_input || attr == hwmon_pwm_freq)
+			return 0644;
+		return 0;
 	default:
 		return 0;
 	}
@@ -157,12 +293,14 @@ static const struct hwmon_channel_info * const s5_temp_info[] = {
 
 static const struct hwmon_channel_info * const s5_fan_info[] = {
 	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT),
+	HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_FREQ),
 	NULL
 };
 
 static const struct hwmon_ops s5_hwmon_ops = {
 	.is_visible = s5_is_visible,
 	.read = s5_read,
+	.write = s5_write,
 };
 
 static const struct hwmon_chip_info s5_temp_chip_info = {
@@ -175,6 +313,42 @@ static const struct hwmon_chip_info s5_fan_chip_info = {
 	.info = s5_fan_info,
 };
 
+static int s5_get_fan_data(struct device *dev, struct device_node *fan_np,
+			   struct s5_hwmon *hwmon)
+{
+	struct of_phandle_args args;
+	int ret;
+
+	ret = of_parse_phandle_with_args(fan_np, "pwms", "#pwm-cells", 0,
+					 &args);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to parse fan PWM\n");
+
+	if (args.np != dev->of_node || args.args_count != 2 || !args.args[0] ||
+	    args.args[1] & ~PWM_POLARITY_INVERTED) {
+		of_node_put(args.np);
+		return dev_err_probe(dev, -EINVAL, "invalid fan PWM specifier\n");
+	}
+
+	hwmon->pwm_period = args.args[0];
+	hwmon->pwm_inverted = args.args[1] & PWM_POLARITY_INVERTED;
+	of_node_put(args.np);
+
+	if (of_property_present(fan_np, "pulses-per-revolution")) {
+		ret = of_property_read_u32(fan_np, "pulses-per-revolution",
+					   &hwmon->pulses_per_revolution);
+		if (ret)
+			return dev_err_probe(dev, ret,
+					     "invalid pulses-per-revolution\n");
+	}
+	if (!hwmon->pulses_per_revolution ||
+	    hwmon->pulses_per_revolution > 4)
+		return dev_err_probe(dev, -EINVAL,
+				     "invalid pulses-per-revolution\n");
+
+	return 0;
+}
+
 static int s5_temp_probe(struct platform_device *pdev)
 {
 	const struct s5_match_data *match_data;
@@ -201,18 +375,11 @@ static int s5_temp_probe(struct platform_device *pdev)
 		hwmon->fan = base;
 		hwmon->pulses_per_revolution = 2;
 		fan_np = of_get_available_child_by_name(dev->of_node, "fan");
-		if (fan_np &&
-		    of_property_present(fan_np, "pulses-per-revolution")) {
-			ret = of_property_read_u32(fan_np, "pulses-per-revolution",
-						   &hwmon->pulses_per_revolution);
+		if (fan_np) {
+			ret = s5_get_fan_data(dev, fan_np, hwmon);
 			if (ret)
-				return dev_err_probe(dev, ret,
-						     "invalid pulses-per-revolution\n");
+				return ret;
 		}
-		if (!hwmon->pulses_per_revolution ||
-		    hwmon->pulses_per_revolution > 4)
-			return dev_err_probe(dev, -EINVAL,
-					     "invalid pulses-per-revolution\n");
 	} else {
 		hwmon->base = base;
 	}
@@ -222,10 +389,17 @@ static int s5_temp_probe(struct platform_device *pdev)
 		return PTR_ERR(hwmon->clk);
 	hwmon->clk_rate = clk_get_rate(hwmon->clk);
 
-	if (is_fan)
+	if (is_fan) {
+		if (hwmon->pwm_period) {
+			ret = s5_write_pwm_period(hwmon);
+			if (ret)
+				return dev_err_probe(dev, ret,
+						     "invalid fan PWM period\n");
+		}
 		s5_fan_enable(hwmon);
-	else
+	} else {
 		s5_temp_enable(hwmon);
+	}
 
 	hwmon_dev = devm_hwmon_device_register_with_info(dev,
 					is_fan ? "lan969x_fan" : "s5_temp", hwmon,
-- 
2.56.0

[PATCH v2 5/6] hwmon: sparx5: register LAN969x fan as a cooling device

[Robert Marko]

Allow the LAN969x hardware fan controller to be used by thermal-zone
cooling maps when cooling-levels are provided on the fan child node.

Translate cooling states to PWM duty-cycle values and keep the cooling
state synchronized with direct pwm1 writes. Register the cooling device
against the fan child so thermal references resolve to the correct node.

Signed-off-by: Robert Marko <robert.marko@sartura.hr>
---
Changes in v2:
- Use hwmon_lock() for cooling callbacks instead of a private mutex.

 Documentation/hwmon/sparx5-temp.rst |  14 +++
 drivers/hwmon/sparx5-temp.c         | 145 ++++++++++++++++++++++++++--
 2 files changed, 150 insertions(+), 9 deletions(-)

diff --git a/Documentation/hwmon/sparx5-temp.rst b/Documentation/hwmon/sparx5-temp.rst
index edb12f890172c..522707ed5a5f5 100644
--- a/Documentation/hwmon/sparx5-temp.rst
+++ b/Documentation/hwmon/sparx5-temp.rst
@@ -49,3 +49,17 @@ PWM consumers. The pwm1 value describes the logical duty cycle independently
 of the output polarity. Frequency requests are rounded to the nearest
 hardware divider value; requests outside the divider range are rejected.
 pwm1_freq reports the resulting frequency.
+
+Thermal cooling
+---------------
+
+With device-tree thermal support enabled, the LAN969x fan can also act as a
+thermal cooling device. The fan child's cooling-levels property maps cooling
+states to PWM values from 0 to 255, in ascending order. When cooling levels
+are provided, the driver initially selects the highest level.
+
+Manual pwm1 writes remain available and update the reported cooling state
+to the highest state whose PWM value does not exceed the requested value,
+or state zero if the value is below the first level. Subsequent thermal
+cooling requests can override manual PWM settings. Each cooling request
+programs the exact PWM value associated with the requested state.
diff --git a/drivers/hwmon/sparx5-temp.c b/drivers/hwmon/sparx5-temp.c
index bdf08931f5b93..caa3fad367684 100644
--- a/drivers/hwmon/sparx5-temp.c
+++ b/drivers/hwmon/sparx5-temp.c
@@ -14,6 +14,7 @@
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
+#include <linux/thermal.h>
 
 #include <dt-bindings/pwm/pwm.h>
 
@@ -47,10 +48,14 @@ struct s5_hwmon {
 	void __iomem *base;
 	void __iomem *fan;
 	struct clk *clk;
+	struct device *hwmon_dev;
 	unsigned long clk_rate;
 	u32 pulses_per_revolution;
 	u32 pwm_period;
 	bool pwm_inverted;
+	u32 *cooling_levels;
+	unsigned long cooling_state;
+	unsigned long max_cooling_state;
 };
 
 static void s5_temp_enable(struct s5_hwmon *hwmon)
@@ -124,6 +129,20 @@ static int s5_read_fan(struct s5_hwmon *hwmon, long *val)
 	return 0;
 }
 
+static void s5_update_cooling_state(struct s5_hwmon *hwmon, u32 pwm)
+{
+	unsigned long state;
+
+	if (!hwmon->cooling_levels)
+		return;
+
+	for (state = 0; state < hwmon->max_cooling_state; state++)
+		if (pwm < hwmon->cooling_levels[state + 1])
+			break;
+
+	hwmon->cooling_state = state;
+}
+
 static int s5_read_pwm(struct s5_hwmon *hwmon, long *val)
 {
 	u32 data;
@@ -183,17 +202,23 @@ static int s5_read(struct device *dev, enum hwmon_sensor_types type,
 	return -EOPNOTSUPP;
 }
 
-static int s5_write_pwm(struct s5_hwmon *hwmon, long val)
+static void s5_set_pwm(struct s5_hwmon *hwmon, u32 pwm)
 {
 	u32 data;
 
-	if (val < 0 || val > 255)
-		return -EINVAL;
-
 	data = readl_relaxed(hwmon->fan + FAN_CFG);
 	data &= ~FAN_CFG_DUTY_CYCLE;
-	data |= FIELD_PREP(FAN_CFG_DUTY_CYCLE, val);
+	data |= FIELD_PREP(FAN_CFG_DUTY_CYCLE, pwm);
 	writel_relaxed(data, hwmon->fan + FAN_CFG);
+}
+
+static int s5_write_pwm(struct s5_hwmon *hwmon, long val)
+{
+	if (val < 0 || val > 255)
+		return -EINVAL;
+
+	s5_set_pwm(hwmon, val);
+	s5_update_cooling_state(hwmon, val);
 
 	return 0;
 }
@@ -313,6 +338,89 @@ static const struct hwmon_chip_info s5_fan_chip_info = {
 	.info = s5_fan_info,
 };
 
+static int s5_cooling_get_max_state(struct thermal_cooling_device *cdev,
+				    unsigned long *state)
+{
+	struct s5_hwmon *hwmon = cdev->devdata;
+
+	*state = hwmon->max_cooling_state;
+
+	return 0;
+}
+
+static int s5_cooling_get_cur_state(struct thermal_cooling_device *cdev,
+				    unsigned long *state)
+{
+	struct s5_hwmon *hwmon = cdev->devdata;
+
+	hwmon_lock(hwmon->hwmon_dev);
+	*state = hwmon->cooling_state;
+	hwmon_unlock(hwmon->hwmon_dev);
+
+	return 0;
+}
+
+static int s5_cooling_set_cur_state(struct thermal_cooling_device *cdev,
+				    unsigned long state)
+{
+	struct s5_hwmon *hwmon = cdev->devdata;
+
+	if (state > hwmon->max_cooling_state)
+		return -EINVAL;
+
+	hwmon_lock(hwmon->hwmon_dev);
+	s5_set_pwm(hwmon, hwmon->cooling_levels[state]);
+	hwmon->cooling_state = state;
+	hwmon_unlock(hwmon->hwmon_dev);
+
+	return 0;
+}
+
+static const struct thermal_cooling_device_ops s5_cooling_ops = {
+	.get_max_state = s5_cooling_get_max_state,
+	.get_cur_state = s5_cooling_get_cur_state,
+	.set_cur_state = s5_cooling_set_cur_state,
+};
+
+static int s5_get_cooling_data(struct device *dev, struct device_node *fan_np,
+			       struct s5_hwmon *hwmon)
+{
+	u32 *levels;
+	int count, i, ret;
+
+	if (!of_property_present(fan_np, "cooling-levels"))
+		return 0;
+
+	count = of_property_count_u32_elems(fan_np, "cooling-levels");
+	if (count <= 0)
+		return dev_err_probe(dev, count ? : -EINVAL,
+				     "invalid cooling-levels property\n");
+
+	levels = devm_kcalloc(dev, count, sizeof(*levels), GFP_KERNEL);
+	if (!levels)
+		return -ENOMEM;
+	hwmon->cooling_levels = levels;
+
+	ret = of_property_read_u32_array(fan_np, "cooling-levels",
+					 hwmon->cooling_levels, count);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "failed to read cooling-levels\n");
+
+	for (i = 0; i < count; i++) {
+		if (hwmon->cooling_levels[i] > 255)
+			return dev_err_probe(dev, -EINVAL,
+					     "cooling level %d exceeds 255\n", i);
+		if (i && hwmon->cooling_levels[i] < hwmon->cooling_levels[i - 1])
+			return dev_err_probe(dev, -EINVAL,
+					     "cooling levels must be ascending\n");
+	}
+
+	hwmon->max_cooling_state = count - 1;
+
+	return 0;
+}
+
 static int s5_get_fan_data(struct device *dev, struct device_node *fan_np,
 			   struct s5_hwmon *hwmon)
 {
@@ -346,18 +454,19 @@ static int s5_get_fan_data(struct device *dev, struct device_node *fan_np,
 		return dev_err_probe(dev, -EINVAL,
 				     "invalid pulses-per-revolution\n");
 
-	return 0;
+	return s5_get_cooling_data(dev, fan_np, hwmon);
 }
 
 static int s5_temp_probe(struct platform_device *pdev)
 {
 	const struct s5_match_data *match_data;
+	struct thermal_cooling_device *cdev;
 	struct device *dev = &pdev->dev;
-	struct device *hwmon_dev;
 	struct s5_hwmon *hwmon;
 	struct device_node *fan_np __free(device_node) = NULL;
 	void __iomem *base;
 	bool is_fan;
+	u32 initial_pwm;
 	int ret;
 
 	match_data = device_get_match_data(dev);
@@ -397,16 +506,34 @@ static int s5_temp_probe(struct platform_device *pdev)
 						     "invalid fan PWM period\n");
 		}
 		s5_fan_enable(hwmon);
+
+		if (hwmon->cooling_levels) {
+			initial_pwm = hwmon->cooling_levels[hwmon->max_cooling_state];
+			ret = s5_write_pwm(hwmon, initial_pwm);
+			if (ret)
+				return ret;
+		}
 	} else {
 		s5_temp_enable(hwmon);
 	}
 
-	hwmon_dev = devm_hwmon_device_register_with_info(dev,
+	hwmon->hwmon_dev = devm_hwmon_device_register_with_info(dev,
 					is_fan ? "lan969x_fan" : "s5_temp", hwmon,
 					is_fan ? &s5_fan_chip_info :
 						 &s5_temp_chip_info, NULL);
+	if (IS_ERR(hwmon->hwmon_dev))
+		return PTR_ERR(hwmon->hwmon_dev);
+
+	if (IS_ENABLED(CONFIG_THERMAL_OF) && hwmon->cooling_levels) {
+		cdev = devm_thermal_of_child_cooling_device_register(dev, fan_np,
+								     "lan969x-fan", hwmon,
+								     &s5_cooling_ops);
+		if (IS_ERR(cdev))
+			return dev_err_probe(dev, PTR_ERR(cdev),
+					     "failed to register cooling device\n");
+	}
 
-	return PTR_ERR_OR_ZERO(hwmon_dev);
+	return 0;
 }
 
 static const struct s5_match_data lan969x_fan_match_data = {
-- 
2.56.0

[PATCH v2 6/6] arm64: dts: microchip: lan969x: add fan controller

[Robert Marko]

LAN969x provides a PWM fan output and tachometer input in a register
block separate from the temperature sensor. Describe it as its own
fan-controller node and keep the temperature sensor compatible.

Connect the EV23X71A fan to the controller and route its pins. Use a
25 kHz normal-polarity PWM for the board low-side FET. Set cooling
levels so the fan starts at full speed.

Signed-off-by: Robert Marko <robert.marko@sartura.hr>
---
Changes in v2:
- Split the fan controller from the temperature node.
- Add the EV23X71A fan child with board-specific PWM and cooling levels.

 arch/arm64/boot/dts/microchip/lan9691.dtsi         | 7 +++++++
 arch/arm64/boot/dts/microchip/lan9696-ev23x71a.dts | 8 +++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/microchip/lan9691.dtsi b/arch/arm64/boot/dts/microchip/lan9691.dtsi
index 52c22dd1a15d5..039c2014aa341 100644
--- a/arch/arm64/boot/dts/microchip/lan9691.dtsi
+++ b/arch/arm64/boot/dts/microchip/lan9691.dtsi
@@ -522,6 +522,13 @@ sgpio_out: gpio@1 {
 			};
 		};
 
+		fanctrl: fan-controller@e2010348 {
+			compatible = "microchip,lan9691-fan";
+			reg = <0xe2010348 0xc>;
+			clocks = <&fx100_clk>;
+			#pwm-cells = <2>;
+		};
+
 		tmon: hwmon@e2020100 {
 			compatible = "microchip,lan9691-temp", "microchip,sparx5-temp";
 			reg = <0xe2020100 0xc>;
diff --git a/arch/arm64/boot/dts/microchip/lan9696-ev23x71a.dts b/arch/arm64/boot/dts/microchip/lan9696-ev23x71a.dts
index abb21a8bace9e..3cbe5beebce1d 100644
--- a/arch/arm64/boot/dts/microchip/lan9696-ev23x71a.dts
+++ b/arch/arm64/boot/dts/microchip/lan9696-ev23x71a.dts
@@ -775,9 +775,15 @@ port29: port@29 {
 	};
 };
 
-&tmon {
+&fanctrl {
 	pinctrl-0 = <&fan_pins>;
 	pinctrl-names = "default";
+
+	fan {
+		pwms = <&fanctrl 40000 0>;
+		cooling-levels = <0 128 192 255>;
+		#cooling-cells = <2>;
+	};
 };
 
 &usart0 {
-- 
2.56.0

Re: [PATCH v2 1/6] dt-bindings: hwmon: add Microchip LAN969x fan controller

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 4403 bytes --]

On Mon, Nov 09, 2026 at 02:35:05PM +0100, Robert Marko wrote:
> The LAN969x fan controller has a PWM output and tachometer input in a
> register block separate from the Sparx5-compatible temperature sensor.
> Describe it with its own compatible and binding.
> 
> The optional fan child specifies PWM period and polarity, tachometer
> pulses per revolution, and thermal cooling levels.
> 
> Signed-off-by: Robert Marko <robert.marko@sartura.hr>
> ---
> Changes in v2:
> - Describe the fan controller in a separate binding and compatible.
> - Keep the existing temperature-sensor binding unchanged.

So, I think that this device has been modelled incorrectly from the
outset. "devcpu_gcb" should probably be a syscon/simplemfd, as least
going off of what I see in
https://microchip-ung.github.io/lan969x-automotive_reginfo/reginfo_LAN969x-Automotive.html?select=devcpu_gcb
and the fact that we see silly offsets in the dts:
		reset: reset-controller@e201000c {
			reg = <0xe201000c 0x4>;
		};

		gpio: pinctrl@e20100d4 {
			reg = <0xe20100d4 0xd4>,
			      <0xe2010370 0xa8>;
		};

		mdio0: mdio@e20101a8 {
			reg = <0xe20101a8 0x24>;
		};

		mdio1: mdio@e20101cc {
			reg = <0xe20101cc 0x24>;
		};

		sgpio: gpio@e2010230 {
			reg = <0xe2010230 0x118>;
		};
That ship has sailed I think though, so I'm not going to ask you to
rework this whole device.

> 
>  .../bindings/hwmon/microchip,lan9691-fan.yaml | 83 +++++++++++++++++++
>  1 file changed, 83 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/microchip,lan9691-fan.yaml
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/microchip,lan9691-fan.yaml b/Documentation/devicetree/bindings/hwmon/microchip,lan9691-fan.yaml
> new file mode 100644
> index 0000000000000..0b7d38a6d20ae
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/microchip,lan9691-fan.yaml
> @@ -0,0 +1,83 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/microchip,lan9691-fan.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Microchip LAN969x Fan Controller
> +
> +maintainers:
> +  - Robert Marko <robert.marko@sartura.hr>
> +
> +description: |
> +  LAN969x fan controller with a PWM output and tachometer input. The fan
> +  child's pwms property references this node to specify the PWM period and
> +  polarity.
> +
> +properties:
> +  compatible:
> +    const: microchip,lan9691-fan
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    items:
> +      - description: System reference clock
> +
> +  '#pwm-cells':
> +    const: 2
> +    description: |
> +      Number of cells in a PWM specifier.
> +      - cell 0: PWM period in nanoseconds
> +      - cell 1: PWM polarity: 0 or PWM_POLARITY_INVERTED
> +
> +  fan:
> +    $ref: fan-common.yaml#
> +    unevaluatedProperties: false
> +
> +    properties:
> +      cooling-levels:
> +        description:
> +          PWM duty-cycle values corresponding to thermal cooling states.
> +        items:
> +          maximum: 255
> +
> +      pulses-per-revolution:
> +        minimum: 1
> +        maximum: 4
> +        default: 2
> +
> +    required:
> +      - pwms
> +
> +    dependencies:
> +      '#cooling-cells':
> +        - cooling-levels
> +      cooling-levels:
> +        - '#cooling-cells'
> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +  - '#pwm-cells'
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/pwm/pwm.h>
> +
> +    fanctrl: fan-controller@e2010348 {
> +        compatible = "microchip,lan9691-fan";
> +        reg = <0xe2010348 0xc>;

btw, how do I translate the addresses you have here to those in
https://microchip-ung.github.io/lan969x-automotive_reginfo/reginfo_LAN969x-Automotive.html?select=devcpu_gcb,fan_ctrl
? Or are you looking at a register map in a different form?

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

Cheers,
Conor.

> +        clocks = <&sys_clk>;
> +        #pwm-cells = <2>;
> +
> +        fan {
> +            pwms = <&fanctrl 40000 PWM_POLARITY_INVERTED>;
> +            cooling-levels = <0 128 192 255>;
> +            #cooling-cells = <2>;
> +        };
> +    };
> -- 
> 2.56.0
> 

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