[PATCH v6 0/3] Add devicetree support for max6639

[PATCH v6 0/3] Add devicetree support for max6639

[Naresh Solanki]

These patches adds devicetree support for MAX6639.

Changes in V6:
- Remove unused header file
- minor cleanup 
Changes in V5:
- Add pwms support
Changes V4:
- Fix dt error
- update comment
Changes V3:
- correct fan dt property name
- remove unrelevent changes
Changes V2:
- Fix dt schema error.
Changes:
- Add fan-common dt schema.
- add dt-binding support for max6639
- add max6639 specific property

Marcello Sylvester Bauer (1):
  dt-bindings: hwmon: Add binding for max6639

Naresh Solanki (2):
  dt-bindings: hwmon: fan: Add fan binding to schema
  hwmon: (max6639) Change from pdata to dt configuration

 .../devicetree/bindings/hwmon/fan-common.yaml |  42 ++
 .../bindings/hwmon/maxim,max6639.yaml         |  93 ++++
 drivers/hwmon/Kconfig                         |   1 +
 drivers/hwmon/max6639.c                       | 460 +++++++++++++++---
 include/linux/platform_data/max6639.h         |  15 -
 5 files changed, 522 insertions(+), 89 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml
 create mode 100644 Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
 delete mode 100644 include/linux/platform_data/max6639.h


base-commit: 27fea302952d8c90cafbdbee96bafeca03544401
-- 
2.37.3

[PATCH v6 1/3] dt-bindings: hwmon: fan: Add fan binding to schema

[Naresh Solanki]

Add common fan properties bindings to a schema.

Bindings for fan controllers can reference the common schema for the
fan

child nodes:

  patternProperties:
    "^fan@[0-2]":
      type: object
      $ref: fan-common.yaml#

Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
---
 .../devicetree/bindings/hwmon/fan-common.yaml | 42 +++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml

diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
new file mode 100644
index 000000000000..1954882eed77
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common fan properties
+
+maintainers:
+  - Naresh Solanki <naresh.solanki@9elements.com>
+
+properties:
+  max-rpm:
+    description:
+      Max RPM supported by fan.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  pulses-per-revolution:
+    description:
+      The number of pulse from fan sensor per revolution.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  target-rpm:
+    description:
+      Target RPM the fan should be configured during driver probe.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  pwms:
+    description:
+      PWM provider.
+
+  label:
+    description:
+      Optional fan label
+
+  fan-supply:
+    description:
+      Power supply for fan.
+
+additionalProperties: true
+
+...
-- 
2.37.3

[PATCH v6 2/3] dt-bindings: hwmon: Add binding for max6639

[Naresh Solanki]

From: Marcello Sylvester Bauer <sylv@sylv.io>

Add Devicetree binding documentation for Maxim MAX6639 temperature
monitor with PWM fan-speed controller.

Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
---
 .../bindings/hwmon/maxim,max6639.yaml         | 93 +++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml

diff --git a/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml b/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
new file mode 100644
index 000000000000..da040b11d2ab
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
@@ -0,0 +1,93 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+
+$id: http://devicetree.org/schemas/hwmon/maxim,max6639.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Maxim max6639
+
+maintainers:
+  - Roland Stigge <stigge@antcom.de>
+
+description: |
+  The MAX6639 is a 2-channel temperature monitor with dual, automatic, PWM
+  fan-speed controller.  It monitors its own temperature and one external
+  diode-connected transistor or the temperatures of two external diode-connected
+  transistors, typically available in CPUs, FPGAs, or GPUs.
+
+  Datasheets:
+    https://datasheets.maximintegrated.com/en/ds/MAX6639-MAX6639F.pdf
+
+properties:
+  compatible:
+    enum:
+      - maxim,max6639
+
+  reg:
+    maxItems: 1
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+  '#pwm-cells':
+    const: 3
+
+required:
+  - compatible
+  - reg
+
+patternProperties:
+  "^fan@[0-1]$":
+    type: object
+    description: |
+      Represents the two fans and their specific configuration.
+
+    $ref: fan-common.yaml#
+
+    properties:
+      reg:
+        description: |
+          The fan number.
+        items:
+          minimum: 0
+          maximum: 1
+
+    required:
+      - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        fan1: fan-controller@10 {
+            compatible = "maxim,max6639";
+            reg = <0x10>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+            #pwm-cells = <3>;
+
+            fan@0 {
+                reg = <0x0>;
+                pulses-per-revolution = <2>;
+                max-rpm = <4000>;
+                target-rpm = <1000>;
+                pwms = <&fan1 0 25000 0>;
+            };
+
+            fan@1 {
+                reg = <0x1>;
+                pulses-per-revolution = <2>;
+                max-rpm = <8000>;
+                pwms = <&fan1 1 25000 0>;
+            };
+            };
+    };
+...
-- 
2.37.3

[PATCH v6 3/3] hwmon: (max6639) Change from pdata to dt configuration

[Naresh Solanki]

max6639_platform_data is not used by any in-kernel driver and does not
address the MAX6639 fans separately.
Move to device tree configuration with explicit properties to configure
each fan.

Non-DT platform can still use this module with its default
configuration.

Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
---
 drivers/hwmon/Kconfig                 |   1 +
 drivers/hwmon/max6639.c               | 460 +++++++++++++++++++++-----
 include/linux/platform_data/max6639.h |  15 -
 3 files changed, 387 insertions(+), 89 deletions(-)
 delete mode 100644 include/linux/platform_data/max6639.h

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 3176c33af6c6..56d9004b7a38 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1115,6 +1115,7 @@ config SENSORS_MAX6621
 config SENSORS_MAX6639
 	tristate "Maxim MAX6639 sensor chip"
 	depends on I2C
+	depends on PWM
 	help
 	  If you say yes here you get support for the MAX6639
 	  sensor chips.
diff --git a/drivers/hwmon/max6639.c b/drivers/hwmon/max6639.c
index 9b895402c80d..058d1a5c6082 100644
--- a/drivers/hwmon/max6639.c
+++ b/drivers/hwmon/max6639.c
@@ -19,7 +19,7 @@
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
-#include <linux/platform_data/max6639.h>
+#include <linux/pwm.h>
 
 /* Addresses to scan */
 static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
@@ -54,11 +54,18 @@ static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
 #define MAX6639_GCONFIG_PWM_FREQ_HI		0x08
 
 #define MAX6639_FAN_CONFIG1_PWM			0x80
-
+#define MAX6639_REG_FAN_CONFIG2a_PWM_POL	0x02
 #define MAX6639_FAN_CONFIG3_THERM_FULL_SPEED	0x40
+#define MAX6639_FAN_CONFIG3_FREQ_MASK		0x03
+#define MAX6639_REG_TARGTDUTY_SLOT		120
 
+/* Tach supported range. This internally controls tach frequency */
 static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };
 
+/* Supported PWM frequency */
+static const unsigned int freq_table[] = { 20, 33, 50, 100, 5000, 8333, 12500,
+					   25000 };
+
 #define FAN_FROM_REG(val, rpm_range)	((val) == 0 || (val) == 255 ? \
 				0 : (rpm_ranges[rpm_range] * 30) / (val))
 #define TEMP_LIMIT_TO_REG(val)	clamp_val((val) / 1000, 0, 255)
@@ -76,20 +83,24 @@ struct max6639_data {
 	u16 temp[2];		/* Temperature, in 1/8 C, 0..255 C */
 	bool temp_fault[2];	/* Detected temperature diode failure */
 	u8 fan[2];		/* Register value: TACH count for fans >=30 */
+	struct pwm_device	*pwmd[2]; /* max6639 has two pwm device */
+	u32 target_rpm[2];
+	u32 max_rpm[2];
+
 	u8 status;		/* Detected channel alarms and fan failures */
 
 	/* Register values only written to */
-	u8 pwm[2];		/* Register value: Duty cycle 0..120 */
 	u8 temp_therm[2];	/* THERM Temperature, 0..255 C (->_max) */
 	u8 temp_alert[2];	/* ALERT Temperature, 0..255 C (->_crit) */
 	u8 temp_ot[2];		/* OT Temperature, 0..255 C (->_emergency) */
 
 	/* Register values initialized only once */
-	u8 ppr;			/* Pulses per rotation 0..3 for 1..4 ppr */
-	u8 rpm_range;		/* Index in above rpm_ranges table */
-
+	u8 ppr[2];		/* Pulses per rotation 0..3 for 1..4 ppr */
+	u8 rpm_range[2];	/* Index in above rpm_ranges table */
 	/* Optional regulator for FAN supply */
 	struct regulator *reg;
+	/* max6639 pwm chip */
+	struct pwm_chip chip;
 };
 
 static struct max6639_data *max6639_update_device(struct device *dev)
@@ -280,8 +291,12 @@ static ssize_t pwm_show(struct device *dev, struct device_attribute *dev_attr,
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 	struct max6639_data *data = dev_get_drvdata(dev);
+	struct pwm_state state;
+
+	pwm_get_state(data->pwmd[attr->index], &state);
+
+	return sprintf(buf, "%d\n", pwm_get_relative_duty_cycle(&state, 255));
 
-	return sprintf(buf, "%d\n", data->pwm[attr->index] * 255 / 120);
 }
 
 static ssize_t pwm_store(struct device *dev,
@@ -290,9 +305,9 @@ static ssize_t pwm_store(struct device *dev,
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 	struct max6639_data *data = dev_get_drvdata(dev);
-	struct i2c_client *client = data->client;
 	unsigned long val;
 	int res;
+	struct pwm_state state;
 
 	res = kstrtoul(buf, 10, &val);
 	if (res)
@@ -300,12 +315,12 @@ static ssize_t pwm_store(struct device *dev,
 
 	val = clamp_val(val, 0, 255);
 
-	mutex_lock(&data->update_lock);
-	data->pwm[attr->index] = (u8)(val * 120 / 255);
-	i2c_smbus_write_byte_data(client,
-				  MAX6639_REG_TARGTDUTY(attr->index),
-				  data->pwm[attr->index]);
-	mutex_unlock(&data->update_lock);
+	pwm_get_state(data->pwmd[attr->index], &state);
+	pwm_set_relative_duty_cycle(&state, val, 255);
+	res = pwm_apply_state(data->pwmd[attr->index], &state);
+	if (res)
+		return res;
+
 	return count;
 }
 
@@ -319,7 +334,7 @@ static ssize_t fan_input_show(struct device *dev,
 		return PTR_ERR(data);
 
 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[attr->index],
-		       data->rpm_range));
+		       data->rpm_range[attr->index]));
 }
 
 static ssize_t alarm_show(struct device *dev,
@@ -386,29 +401,41 @@ static struct attribute *max6639_attrs[] = {
 ATTRIBUTE_GROUPS(max6639);
 
 /*
- *  returns respective index in rpm_ranges table
- *  1 by default on invalid range
+ *  Get respective index in rpm_ranges table
  */
-static int rpm_range_to_reg(int range)
+static int rpm_range_to_index(struct device *dev, u8 *index, int rpm)
 {
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
-		if (rpm_ranges[i] == range)
-			return i;
+	if (rpm < 0)
+		return -EINVAL;
+
+	/* Set index based on chip support */
+	switch (rpm) {
+	case 0 ... 2000:
+		*index = 0;
+		break;
+	case 2001 ... 4000:
+		*index = 1;
+		break;
+	case 4001 ... 8000:
+		*index = 2;
+		break;
+	case 8001 ... 16000:
+		*index = 3;
+		break;
+	default:
+		/* Use max range for higher RPM */
+		dev_warn(dev,
+		    "RPM higher than supported range. Default to 16000 RPM");
+		*index = 3;
 	}
-
-	return 1; /* default: 4000 RPM */
+	return 0;
 }
 
 static int max6639_init_client(struct i2c_client *client,
 			       struct max6639_data *data)
 {
-	struct max6639_platform_data *max6639_info =
-		dev_get_platdata(&client->dev);
-	int i;
-	int rpm_range = 1; /* default: 4000 RPM */
-	int err;
+	int i, err;
+	struct pwm_state state;
 
 	/* Reset chip to default values, see below for GCONFIG setup */
 	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
@@ -416,51 +443,29 @@ static int max6639_init_client(struct i2c_client *client,
 	if (err)
 		goto exit;
 
-	/* Fans pulse per revolution is 2 by default */
-	if (max6639_info && max6639_info->ppr > 0 &&
-			max6639_info->ppr < 5)
-		data->ppr = max6639_info->ppr;
-	else
-		data->ppr = 2;
-	data->ppr -= 1;
-
-	if (max6639_info)
-		rpm_range = rpm_range_to_reg(max6639_info->rpm_range);
-	data->rpm_range = rpm_range;
-
 	for (i = 0; i < 2; i++) {
 
 		/* Set Fan pulse per revolution */
-		err = i2c_smbus_write_byte_data(client,
-				MAX6639_REG_FAN_PPR(i),
-				data->ppr << 6);
+		err = i2c_smbus_write_byte_data(client,	MAX6639_REG_FAN_PPR(i),
+						data->ppr[i] << 6);
 		if (err)
 			goto exit;
 
 		/* Fans config PWM, RPM */
 		err = i2c_smbus_write_byte_data(client,
-			MAX6639_REG_FAN_CONFIG1(i),
-			MAX6639_FAN_CONFIG1_PWM | rpm_range);
-		if (err)
-			goto exit;
-
-		/* Fans PWM polarity high by default */
-		if (max6639_info && max6639_info->pwm_polarity == 0)
-			err = i2c_smbus_write_byte_data(client,
-				MAX6639_REG_FAN_CONFIG2a(i), 0x00);
-		else
-			err = i2c_smbus_write_byte_data(client,
-				MAX6639_REG_FAN_CONFIG2a(i), 0x02);
+						MAX6639_REG_FAN_CONFIG1(i),
+						MAX6639_FAN_CONFIG1_PWM |
+						data->rpm_range[i]);
 		if (err)
 			goto exit;
 
 		/*
-		 * /THERM full speed enable,
+		 * /THERM full speed disable,
 		 * PWM frequency 25kHz, see also GCONFIG below
 		 */
 		err = i2c_smbus_write_byte_data(client,
-			MAX6639_REG_FAN_CONFIG3(i),
-			MAX6639_FAN_CONFIG3_THERM_FULL_SPEED | 0x03);
+						MAX6639_REG_FAN_CONFIG3(i),
+						0x03);
 		if (err)
 			goto exit;
 
@@ -469,31 +474,35 @@ static int max6639_init_client(struct i2c_client *client,
 		data->temp_alert[i] = 90;
 		data->temp_ot[i] = 100;
 		err = i2c_smbus_write_byte_data(client,
-				MAX6639_REG_THERM_LIMIT(i),
-				data->temp_therm[i]);
+						MAX6639_REG_THERM_LIMIT(i),
+						data->temp_therm[i]);
 		if (err)
 			goto exit;
 		err = i2c_smbus_write_byte_data(client,
-				MAX6639_REG_ALERT_LIMIT(i),
-				data->temp_alert[i]);
+						MAX6639_REG_ALERT_LIMIT(i),
+						data->temp_alert[i]);
 		if (err)
 			goto exit;
 		err = i2c_smbus_write_byte_data(client,
-				MAX6639_REG_OT_LIMIT(i), data->temp_ot[i]);
+						MAX6639_REG_OT_LIMIT(i),
+						data->temp_ot[i]);
 		if (err)
 			goto exit;
 
-		/* PWM 120/120 (i.e. 100%) */
-		data->pwm[i] = 120;
-		err = i2c_smbus_write_byte_data(client,
-				MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
+		/* Configure PWM controller */
+		pwm_get_state(data->pwmd[i], &state);
+		pwm_set_relative_duty_cycle(&state, data->target_rpm[i],
+					    data->max_rpm[i]);
+		err = pwm_apply_state(data->pwmd[i], &state);
 		if (err)
 			goto exit;
+
 	}
 	/* Start monitoring */
 	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
 		MAX6639_GCONFIG_DISABLE_TIMEOUT | MAX6639_GCONFIG_CH2_LOCAL |
 		MAX6639_GCONFIG_PWM_FREQ_HI);
+
 exit:
 	return err;
 }
@@ -524,12 +533,276 @@ static void max6639_regulator_disable(void *data)
 	regulator_disable(data);
 }
 
+static int max6639_probe_child_from_dt(struct i2c_client *client,
+				      struct device_node *child,
+				      struct max6639_data *data)
+
+{
+	struct device *dev = &client->dev;
+	u32 i, maxrpm;
+	int val, err;
+
+	err = of_property_read_u32(child, "reg", &i);
+	if (err) {
+		dev_err(dev, "missing reg property of %pOFn\n", child);
+		return err;
+	}
+
+	if (i >= 2) {
+		dev_err(dev, "invalid reg %d of %pOFn\n", i, child);
+		return -EINVAL;
+	}
+
+	err = of_property_read_u32(child, "pulses-per-revolution", &val);
+	if (err) {
+		dev_err(dev, "missing pulses-per-revolution property of %pOFn",
+			child);
+		return err;
+	}
+
+	if (val < 0 || val > 5) {
+		dev_err(dev, "invalid pulses-per-revolution %d of %pOFn\n", val,
+			child);
+		return -EINVAL;
+	}
+	data->ppr[i] = val;
+
+	err = of_property_read_u32(child, "max-rpm", &maxrpm);
+	if (err) {
+		dev_err(dev, "missing max-rpm property of %pOFn\n", child);
+		return err;
+	}
+
+	err = rpm_range_to_index(dev, &data->rpm_range[i], maxrpm);
+	if (err) {
+		dev_err(dev, "invalid max-rpm %d of %pOFn\n", maxrpm, child);
+		return err;
+	}
+	data->max_rpm[i] = maxrpm;
+
+	err = of_property_read_u32(child, "target-rpm", &val);
+	/* Use provided target RPM else default to maxrpm */
+	if (!err)
+		data->target_rpm[i] = val;
+	else
+		data->target_rpm[i] = maxrpm;
+
+	/* Get pwms property for PWM control */
+	data->pwmd[i] = devm_fwnode_pwm_get(dev, &child->fwnode, NULL);
+
+	if (!IS_ERR(data->pwmd[i]))
+		return 0;
+
+	if (PTR_ERR(data->pwmd[i]) == -EPROBE_DEFER)
+		return PTR_ERR(data->pwmd[i]);
+
+	dev_dbg(dev, "Using chip default PWM");
+	data->pwmd[i] = pwm_request_from_chip(&data->chip, i, NULL);
+	if (!IS_ERR(data->pwmd[i]))
+		return 0;
+
+	dev_dbg(dev, "Failed to configure pwm for fan %d", i);
+	return PTR_ERR_OR_ZERO(data->pwmd[i]);
+}
+
+static int max6639_probe_from_dt(struct i2c_client *client,
+				 struct max6639_data *data)
+{
+	struct device *dev = &client->dev;
+	const struct device_node *np = dev->of_node;
+	struct device_node *child;
+	int err;
+
+	/* Compatible with non-DT platforms */
+	if (!np)
+		return 0;
+
+	for_each_child_of_node(np, child) {
+		if (strcmp(child->name, "fan"))
+			continue;
+
+		err = max6639_probe_child_from_dt(client, child, data);
+		if (err) {
+			of_node_put(child);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+static struct max6639_data *to_max6639_pwm(struct pwm_chip *chip)
+{
+	return container_of(chip, struct max6639_data, chip);
+}
+
+static void max6639_pwm_get_state(struct pwm_chip *chip,
+				  struct pwm_device *pwm,
+				  struct pwm_state *state)
+{
+
+	struct max6639_data *data = to_max6639_pwm(chip);
+	struct i2c_client *client = data->client;
+	int value, i = pwm->hwpwm, x;
+	unsigned int freq;
+
+	mutex_lock(&data->update_lock);
+
+	value = i2c_smbus_read_byte_data(client, MAX6639_REG_FAN_CONFIG1(i));
+	if (value < 0)
+		goto abort;
+
+	if (value & MAX6639_FAN_CONFIG1_PWM) {
+		state->enabled = true;
+
+		/* Determine frequency from respective registers */
+		value = i2c_smbus_read_byte_data(client,
+						 MAX6639_REG_FAN_CONFIG3(i));
+		if (value < 0)
+			goto abort;
+		x = value & MAX6639_FAN_CONFIG3_FREQ_MASK;
+
+		value = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
+		if (value < 0)
+			goto abort;
+		if (value & MAX6639_GCONFIG_PWM_FREQ_HI)
+			x |= 0x4;
+		x &= 0x7;
+		freq = freq_table[x];
+
+		state->period = DIV_ROUND_UP(NSEC_PER_SEC, freq);
+
+		value = i2c_smbus_read_byte_data(client,
+						 MAX6639_REG_TARGTDUTY(i));
+		if (value < 0)
+			goto abort;
+		/* max6639 supports 120 slots only */
+		state->duty_cycle = mul_u64_u32_div(state->period, value, 120);
+
+		value = i2c_smbus_read_byte_data(client,
+						 MAX6639_REG_FAN_CONFIG2a(i));
+		if (value < 0)
+			goto abort;
+		value &= MAX6639_REG_FAN_CONFIG2a_PWM_POL;
+		state->polarity = (value != 0);
+	} else
+		state->enabled = false;
+
+abort:
+	mutex_unlock(&data->update_lock);
+
+}
+
+static int max6639_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			     const struct pwm_state *state)
+{
+	struct max6639_data *data = to_max6639_pwm(chip);
+	struct i2c_client *client = data->client;
+	int value = 0, i = pwm->hwpwm, x;
+	unsigned int freq;
+	struct pwm_state cstate;
+
+	cstate = pwm->state;
+
+	mutex_lock(&data->update_lock);
+
+	if (state->period != cstate.period) {
+		/* Configure frequency */
+		freq = DIV_ROUND_UP_ULL(NSEC_PER_SEC, state->period);
+		/* Chip supports limited number of frequency */
+		for (x = 0; x < sizeof(freq_table); x++)
+			if (freq <= freq_table[x])
+				break;
+
+		value = i2c_smbus_read_byte_data(client,
+						 MAX6639_REG_FAN_CONFIG3(i));
+		if (value < 0)
+			goto abort;
+		value &= ~MAX6639_FAN_CONFIG3_FREQ_MASK;
+		value |= (x & MAX6639_FAN_CONFIG3_FREQ_MASK);
+		value = i2c_smbus_write_byte_data(client,
+						  MAX6639_REG_FAN_CONFIG3(i),
+						  value);
+
+		value = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
+		if (value < 0)
+			goto abort;
+
+		if (x >> 2)
+			value &= ~MAX6639_GCONFIG_PWM_FREQ_HI;
+		else
+			value |= MAX6639_GCONFIG_PWM_FREQ_HI;
+		value = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
+						  value);
+		if (value < 0)
+			goto abort;
+	}
+
+	/* Configure dutycycle */
+	if (state->duty_cycle != cstate.duty_cycle ||
+	    state->period != cstate.period) {
+		value = DIV_ROUND_DOWN_ULL(
+				state->duty_cycle * MAX6639_REG_TARGTDUTY_SLOT,
+				state->period);
+		value = i2c_smbus_write_byte_data(client,
+						  MAX6639_REG_TARGTDUTY(i),
+						  value);
+		if (value < 0)
+			goto abort;
+	}
+
+	/* Configure polarity */
+	if (state->polarity != cstate.polarity) {
+		value = i2c_smbus_read_byte_data(client,
+						 MAX6639_REG_FAN_CONFIG2a(i));
+		if (value < 0)
+			goto abort;
+		if (state->polarity == PWM_POLARITY_NORMAL)
+			value |= MAX6639_REG_FAN_CONFIG2a_PWM_POL;
+		else
+			value &= ~MAX6639_REG_FAN_CONFIG2a_PWM_POL;
+		value = i2c_smbus_write_byte_data(client,
+						  MAX6639_REG_FAN_CONFIG2a(i),
+						  value);
+		if (value < 0)
+			goto abort;
+	}
+
+	if (state->enabled == cstate.enabled)
+		goto abort;
+
+	value = i2c_smbus_read_byte_data(client, MAX6639_REG_FAN_CONFIG1(i));
+	if (value < 0)
+		goto abort;
+	if (state->enabled)
+		value |= MAX6639_FAN_CONFIG1_PWM;
+	else
+		value &= ~MAX6639_FAN_CONFIG1_PWM;
+
+	value = i2c_smbus_write_byte_data(client, MAX6639_REG_FAN_CONFIG1(i),
+					  value);
+	if (value < 0)
+		goto abort;
+	value = 0;
+
+abort:
+	mutex_unlock(&data->update_lock);
+
+	return value;
+}
+
+static const struct pwm_ops max6639_pwm_ops = {
+	.apply = max6639_pwm_apply,
+	.get_state = max6639_pwm_get_state,
+	.owner = THIS_MODULE,
+};
+
 static int max6639_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
 	struct max6639_data *data;
 	struct device *hwmon_dev;
-	int err;
+	int err, i;
 
 	data = devm_kzalloc(dev, sizeof(struct max6639_data), GFP_KERNEL);
 	if (!data)
@@ -537,11 +810,23 @@ static int max6639_probe(struct i2c_client *client)
 
 	data->client = client;
 
+	/* Add PWM controller of max6639 */
+	data->chip.dev = dev;
+	data->chip.ops = &max6639_pwm_ops;
+	data->chip.npwm = 2;
+
+	err = devm_pwmchip_add(dev, &data->chip);
+	if (err < 0) {
+		return dev_err_probe(dev, err, "failed to add PWM chip\n");
+	}
+
 	data->reg = devm_regulator_get_optional(dev, "fan");
 	if (IS_ERR(data->reg)) {
-		if (PTR_ERR(data->reg) != -ENODEV)
-			return PTR_ERR(data->reg);
-
+		if (PTR_ERR(data->reg) != -ENODEV) {
+			err = (int)PTR_ERR(data->reg);
+			return dev_err_probe(dev, err,
+					     "Failed looking up fan supply\n");
+		}
 		data->reg = NULL;
 	} else {
 		/* Spin up fans */
@@ -560,6 +845,22 @@ static int max6639_probe(struct i2c_client *client)
 
 	mutex_init(&data->update_lock);
 
+	/* Below are defaults leter overridden by DT properties */
+	for (i = 0; i < 2; i++) {
+		/* 4000 RPM */
+		data->rpm_range[i] = 1;
+		data->ppr[i] = 2;
+		/* Max. temp. 80C/90C/100C */
+		data->temp_therm[i] = 80;
+		data->temp_alert[i] = 90;
+		data->temp_ot[i] = 100;
+	}
+
+	/* Probe from DT to get configuration */
+	err = max6639_probe_from_dt(client, data);
+	if (err)
+		return err;
+
 	/* Initialize the max6639 chip */
 	err = max6639_init_client(client, data);
 	if (err < 0)
@@ -571,6 +872,7 @@ static int max6639_probe(struct i2c_client *client)
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }
 
+#if IS_ENABLED(CONFIG_PM_SLEEP)
 static int max6639_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
@@ -608,6 +910,7 @@ static int max6639_resume(struct device *dev)
 	return i2c_smbus_write_byte_data(client,
 			MAX6639_REG_GCONFIG, ret & ~MAX6639_GCONFIG_STANDBY);
 }
+#endif
 
 static const struct i2c_device_id max6639_id[] = {
 	{"max6639", 0},
@@ -616,13 +919,22 @@ static const struct i2c_device_id max6639_id[] = {
 
 MODULE_DEVICE_TABLE(i2c, max6639_id);
 
-static DEFINE_SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);
+#ifdef CONFIG_OF
+static const struct of_device_id maxim_of_platform_match[] = {
+	{.compatible = "maxim,max6639"},
+	{},
+};
+MODULE_DEVICE_TABLE(of, maxim_of_platform_match);
+#endif
+
+static SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);
 
 static struct i2c_driver max6639_driver = {
 	.class = I2C_CLASS_HWMON,
 	.driver = {
 		   .name = "max6639",
 		   .pm = pm_sleep_ptr(&max6639_pm_ops),
+		   .of_match_table = of_match_ptr(maxim_of_platform_match),
 		   },
 	.probe_new = max6639_probe,
 	.id_table = max6639_id,
diff --git a/include/linux/platform_data/max6639.h b/include/linux/platform_data/max6639.h
deleted file mode 100644
index 65bfdb4fdc15..000000000000
--- a/include/linux/platform_data/max6639.h
+++ /dev/null
@@ -1,15 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LINUX_MAX6639_H
-#define _LINUX_MAX6639_H
-
-#include <linux/types.h>
-
-/* platform data for the MAX6639 temperature sensor and fan control */
-
-struct max6639_platform_data {
-	bool pwm_polarity;	/* Polarity low (0) or high (1, default) */
-	int ppr;		/* Pulses per rotation 1..4 (default == 2) */
-	int rpm_range;		/* 2000, 4000 (default), 8000 or 16000 */
-};
-
-#endif /* _LINUX_MAX6639_H */
-- 
2.37.3

Re: [PATCH v6 3/3] hwmon: (max6639) Change from pdata to dt configuration

[Uwe Kleine-König]

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Hello,

On Wed, Nov 16, 2022 at 10:36:15PM +0100, Naresh Solanki wrote:
> max6639_platform_data is not used by any in-kernel driver and does not
> address the MAX6639 fans separately.
> Move to device tree configuration with explicit properties to configure
> each fan.
> 
> Non-DT platform can still use this module with its default
> configuration.
> 
> Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>

What changed here since v5? Please either add a changelog below the
tripple-dash for a new revision, or make sure that all relevant people
get the cover letter.

It seems you didn't address my comments for v5 :-\

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: [PATCH v6 3/3] hwmon: (max6639) Change from pdata to dt configuration

[Naresh Solanki]

On 17-11-2022 01:15 pm, Uwe Kleine-König wrote:
> Hello,
> 
> On Wed, Nov 16, 2022 at 10:36:15PM +0100, Naresh Solanki wrote:
>> max6639_platform_data is not used by any in-kernel driver and does not
>> address the MAX6639 fans separately.
>> Move to device tree configuration with explicit properties to configure
>> each fan.
>>
>> Non-DT platform can still use this module with its default
>> configuration.
>>
>> Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
>> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> 
> What changed here since v5? Please either add a changelog below the
> tripple-dash for a new revision, or make sure that all relevant people
> get the cover letter.
> 
> It seems you didn't address my comments for v5 :-\
Not sure what I missed but did following changes:
Removed unused header max6639.h
Used dev_err_probe instead,
Removed of_pwm_n_cells,
if condition for freq_table
removed pwm_get_state & instead use pwm->state
division/multiplication optimizations,
indentation of freq_table,

> 
> Best regards
> Uwe
> 

Thanks,
Naresh

Re: [PATCH v6 3/3] hwmon: (max6639) Change from pdata to dt configuration

[Uwe Kleine-König]

[-- Attachment #1: Type: text/plain, Size: 2193 bytes --]

On Thu, Nov 17, 2022 at 02:10:45PM +0530, Naresh Solanki wrote:
> 
> 
> On 17-11-2022 01:15 pm, Uwe Kleine-König wrote:
> > Hello,
> > 
> > On Wed, Nov 16, 2022 at 10:36:15PM +0100, Naresh Solanki wrote:
> > > max6639_platform_data is not used by any in-kernel driver and does not
> > > address the MAX6639 fans separately.
> > > Move to device tree configuration with explicit properties to configure
> > > each fan.
> > > 
> > > Non-DT platform can still use this module with its default
> > > configuration.
> > > 
> > > Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
> > > Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> > 
> > What changed here since v5? Please either add a changelog below the
> > tripple-dash for a new revision, or make sure that all relevant people
> > get the cover letter.
> > 
> > It seems you didn't address my comments for v5 :-\
> Not sure what I missed but did following changes:
> Removed unused header max6639.h
> Used dev_err_probe instead,
> Removed of_pwm_n_cells,
> if condition for freq_table
> removed pwm_get_state & instead use pwm->state
> division/multiplication optimizations,
> indentation of freq_table,

In the cover letter you just wrote:

| Changes in V6:
| - Remove unused header file
| - minor cleanup

which is too short in my eyes. If you wrote instead:

	Address review feedback by Uwe Kleine-König in patch #3, patches #1 and
	#2 unchanged.

This would be much more helpful as people that were already happy with
v5 wouldn't need to look at the first two patches and I would know that
you addressed my feedback and would have looked in more detail.

What I miss is the most critical part of my feedback, i.e.:
| My overall impression is that this patch mixes too much things. IMHO it
| should be split in (at least)
| 
|  - Add dt support
|  - Drop platform support
|  - Add PWM provider support
|  - Make use of the PWM API
|
| maybe also add the 2nd PWM in a separate step.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: [PATCH v6 3/3] hwmon: (max6639) Change from pdata to dt configuration

[Naresh Solanki]

Hi Uwe,

On 17-11-2022 02:43 pm, Uwe Kleine-König wrote:
> On Thu, Nov 17, 2022 at 02:10:45PM +0530, Naresh Solanki wrote:
>>
>>
>> On 17-11-2022 01:15 pm, Uwe Kleine-König wrote:
>>> Hello,
>>>
>>> On Wed, Nov 16, 2022 at 10:36:15PM +0100, Naresh Solanki wrote:
>>>> max6639_platform_data is not used by any in-kernel driver and does not
>>>> address the MAX6639 fans separately.
>>>> Move to device tree configuration with explicit properties to configure
>>>> each fan.
>>>>
>>>> Non-DT platform can still use this module with its default
>>>> configuration.
>>>>
>>>> Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
>>>> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
>>>
>>> What changed here since v5? Please either add a changelog below the
>>> tripple-dash for a new revision, or make sure that all relevant people
>>> get the cover letter.
>>>
>>> It seems you didn't address my comments for v5 :-\
>> Not sure what I missed but did following changes:
>> Removed unused header max6639.h
>> Used dev_err_probe instead,
>> Removed of_pwm_n_cells,
>> if condition for freq_table
>> removed pwm_get_state & instead use pwm->state
>> division/multiplication optimizations,
>> indentation of freq_table,
> 
> In the cover letter you just wrote:
> 
> | Changes in V6:
> | - Remove unused header file
> | - minor cleanup
> 
> which is too short in my eyes. If you wrote instead:
> 
> 	Address review feedback by Uwe Kleine-König in patch #3, patches #1 and
> 	#2 unchanged.
> 
> This would be much more helpful as people that were already happy with
> v5 wouldn't need to look at the first two patches and I would know that
> you addressed my feedback and would have looked in more detail.
Sure will keep it this way next time.
> 
> What I miss is the most critical part of my feedback, i.e.:
> | My overall impression is that this patch mixes too much things. IMHO it
> | should be split in (at least)
> |
> |  - Add dt support
> |  - Drop platform support
> |  - Add PWM provider support
> |  - Make use of the PWM API
> |
> | maybe also add the 2nd PWM in a separate step.
Sure can do that.
> 
> Best regards
> Uwe
> 
Thanks,
Naresh

Re: [PATCH v6 1/3] dt-bindings: hwmon: fan: Add fan binding to schema

[Guenter Roeck]

On Wed, Nov 16, 2022 at 10:36:13PM +0100, Naresh Solanki wrote:
> Add common fan properties bindings to a schema.
> 
> Bindings for fan controllers can reference the common schema for the
> fan
> 
> child nodes:
> 
>   patternProperties:
>     "^fan@[0-2]":
>       type: object
>       $ref: fan-common.yaml#
> 
> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> ---
>  .../devicetree/bindings/hwmon/fan-common.yaml | 42 +++++++++++++++++++
>  1 file changed, 42 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> new file mode 100644
> index 000000000000..1954882eed77
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> @@ -0,0 +1,42 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Common fan properties
> +
> +maintainers:
> +  - Naresh Solanki <naresh.solanki@9elements.com>
> +
> +properties:
> +  max-rpm:
> +    description:
> +      Max RPM supported by fan.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  pulses-per-revolution:
> +    description:
> +      The number of pulse from fan sensor per revolution.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  target-rpm:
> +    description:
> +      Target RPM the fan should be configured during driver probe.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  pwms:
> +    description:
> +      PWM provider.
> +
> +  label:
> +    description:
> +      Optional fan label
> +
> +  fan-supply:
> +    description:
> +      Power supply for fan.
> +

I still think that at least min-rpm should be added. It is just as common
as max-rpm.

Guenter

> +additionalProperties: true
> +
> +...

Re: [PATCH v6 3/3] hwmon: (max6639) Change from pdata to dt configuration

[Guenter Roeck]

On Thu, Nov 17, 2022 at 10:13:24AM +0100, Uwe Kleine-König wrote:
> On Thu, Nov 17, 2022 at 02:10:45PM +0530, Naresh Solanki wrote:
> > 
> > 
> > On 17-11-2022 01:15 pm, Uwe Kleine-König wrote:
> > > Hello,
> > > 
> > > On Wed, Nov 16, 2022 at 10:36:15PM +0100, Naresh Solanki wrote:
> > > > max6639_platform_data is not used by any in-kernel driver and does not
> > > > address the MAX6639 fans separately.
> > > > Move to device tree configuration with explicit properties to configure
> > > > each fan.
> > > > 
> > > > Non-DT platform can still use this module with its default
> > > > configuration.
> > > > 
> > > > Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
> > > > Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> > > 
> > > What changed here since v5? Please either add a changelog below the
> > > tripple-dash for a new revision, or make sure that all relevant people
> > > get the cover letter.
> > > 
> > > It seems you didn't address my comments for v5 :-\
> > Not sure what I missed but did following changes:
> > Removed unused header max6639.h
> > Used dev_err_probe instead,
> > Removed of_pwm_n_cells,
> > if condition for freq_table
> > removed pwm_get_state & instead use pwm->state
> > division/multiplication optimizations,
> > indentation of freq_table,
> 
> In the cover letter you just wrote:
> 
> | Changes in V6:
> | - Remove unused header file
> | - minor cleanup
> 
> which is too short in my eyes. If you wrote instead:
> 
> 	Address review feedback by Uwe Kleine-König in patch #3, patches #1 and
> 	#2 unchanged.
> 
> This would be much more helpful as people that were already happy with
> v5 wouldn't need to look at the first two patches and I would know that
> you addressed my feedback and would have looked in more detail.
> 
> What I miss is the most critical part of my feedback, i.e.:
> | My overall impression is that this patch mixes too much things. IMHO it
> | should be split in (at least)
> | 
> |  - Add dt support
> |  - Drop platform support
> |  - Add PWM provider support
> |  - Make use of the PWM API
> |
> | maybe also add the 2nd PWM in a separate step.

Those will definitely need to be separate patches. I am far from convinced
that all fan controllers in the hwmon subsystem should implement pwm
providers just to match devicetree requirements. That adds zero value in
99% of all use cases. Actually, I don't know of any use cases where it
would add value or even make sense.

Guenter


> 
> Best regards
> Uwe
> 
> -- 
> Pengutronix e.K.                           | Uwe Kleine-König            |
> Industrial Linux Solutions                 | https://www.pengutronix.de/ |

Re: [PATCH v6 1/3] dt-bindings: hwmon: fan: Add fan binding to schema

[Guenter Roeck]

On Wed, Nov 16, 2022 at 10:36:13PM +0100, Naresh Solanki wrote:
> Add common fan properties bindings to a schema.
> 
> Bindings for fan controllers can reference the common schema for the
> fan
> 
> child nodes:
> 
>   patternProperties:
>     "^fan@[0-2]":
>       type: object
>       $ref: fan-common.yaml#
> 
> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> ---
>  .../devicetree/bindings/hwmon/fan-common.yaml | 42 +++++++++++++++++++
>  1 file changed, 42 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> new file mode 100644
> index 000000000000..1954882eed77
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> @@ -0,0 +1,42 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Common fan properties
> +
> +maintainers:
> +  - Naresh Solanki <naresh.solanki@9elements.com>
> +
> +properties:
> +  max-rpm:
> +    description:
> +      Max RPM supported by fan.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  pulses-per-revolution:
> +    description:
> +      The number of pulse from fan sensor per revolution.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  target-rpm:
> +    description:
> +      Target RPM the fan should be configured during driver probe.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  pwms:
> +    description:
> +      PWM provider.
> +
> +  label:
> +    description:
> +      Optional fan label
> +
> +  fan-supply:
> +    description:
> +      Power supply for fan.
> +

Another property which is definitely missing and needed
will be DC vs. PWM control. That is currently pwm[1-*]_mode
in sysfs attributes, but it is really a fan attribute.

Many fans are DC controlled, so this property is absolutely
necessary.

Guenter

Re: [PATCH v6 1/3] dt-bindings: hwmon: fan: Add fan binding to schema

[Rob Herring]

On Sun, Nov 20, 2022 at 07:13:31AM -0800, Guenter Roeck wrote:
> On Wed, Nov 16, 2022 at 10:36:13PM +0100, Naresh Solanki wrote:
> > Add common fan properties bindings to a schema.
> > 
> > Bindings for fan controllers can reference the common schema for the
> > fan
> > 
> > child nodes:
> > 
> >   patternProperties:
> >     "^fan@[0-2]":
> >       type: object
> >       $ref: fan-common.yaml#
> > 
> > Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> > ---
> >  .../devicetree/bindings/hwmon/fan-common.yaml | 42 +++++++++++++++++++
> >  1 file changed, 42 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> > new file mode 100644
> > index 000000000000..1954882eed77
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> > @@ -0,0 +1,42 @@
> > +# SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Common fan properties
> > +
> > +maintainers:
> > +  - Naresh Solanki <naresh.solanki@9elements.com>
> > +
> > +properties:
> > +  max-rpm:
> > +    description:
> > +      Max RPM supported by fan.
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +
> > +  pulses-per-revolution:
> > +    description:
> > +      The number of pulse from fan sensor per revolution.
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +
> > +  target-rpm:
> > +    description:
> > +      Target RPM the fan should be configured during driver probe.
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +
> > +  pwms:
> > +    description:
> > +      PWM provider.
> > +
> > +  label:
> > +    description:
> > +      Optional fan label
> > +
> > +  fan-supply:
> > +    description:
> > +      Power supply for fan.
> > +
> 
> I still think that at least min-rpm should be added. It is just as common
> as max-rpm.

Or a table if the response is not linear like LEDs/backlights? Though if 
there's a tach, that wouldn't be necessary.

Rob

Re: [PATCH v6 3/3] hwmon: (max6639) Change from pdata to dt configuration

[Rob Herring]

On Sun, Nov 20, 2022 at 07:19:46AM -0800, Guenter Roeck wrote:
> On Thu, Nov 17, 2022 at 10:13:24AM +0100, Uwe Kleine-König wrote:
> > On Thu, Nov 17, 2022 at 02:10:45PM +0530, Naresh Solanki wrote:
> > > 
> > > 
> > > On 17-11-2022 01:15 pm, Uwe Kleine-König wrote:
> > > > Hello,
> > > > 
> > > > On Wed, Nov 16, 2022 at 10:36:15PM +0100, Naresh Solanki wrote:
> > > > > max6639_platform_data is not used by any in-kernel driver and does not
> > > > > address the MAX6639 fans separately.
> > > > > Move to device tree configuration with explicit properties to configure
> > > > > each fan.
> > > > > 
> > > > > Non-DT platform can still use this module with its default
> > > > > configuration.
> > > > > 
> > > > > Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
> > > > > Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> > > > 
> > > > What changed here since v5? Please either add a changelog below the
> > > > tripple-dash for a new revision, or make sure that all relevant people
> > > > get the cover letter.
> > > > 
> > > > It seems you didn't address my comments for v5 :-\
> > > Not sure what I missed but did following changes:
> > > Removed unused header max6639.h
> > > Used dev_err_probe instead,
> > > Removed of_pwm_n_cells,
> > > if condition for freq_table
> > > removed pwm_get_state & instead use pwm->state
> > > division/multiplication optimizations,
> > > indentation of freq_table,
> > 
> > In the cover letter you just wrote:
> > 
> > | Changes in V6:
> > | - Remove unused header file
> > | - minor cleanup
> > 
> > which is too short in my eyes. If you wrote instead:
> > 
> > 	Address review feedback by Uwe Kleine-König in patch #3, patches #1 and
> > 	#2 unchanged.
> > 
> > This would be much more helpful as people that were already happy with
> > v5 wouldn't need to look at the first two patches and I would know that
> > you addressed my feedback and would have looked in more detail.
> > 
> > What I miss is the most critical part of my feedback, i.e.:
> > | My overall impression is that this patch mixes too much things. IMHO it
> > | should be split in (at least)
> > | 
> > |  - Add dt support
> > |  - Drop platform support
> > |  - Add PWM provider support
> > |  - Make use of the PWM API
> > |
> > | maybe also add the 2nd PWM in a separate step.
> 
> Those will definitely need to be separate patches. I am far from convinced
> that all fan controllers in the hwmon subsystem should implement pwm
> providers just to match devicetree requirements. That adds zero value in
> 99% of all use cases. Actually, I don't know of any use cases where it
> would add value or even make sense.

There's no requirement that using a binding means using corresponding 
Linux subsystem. Convenient usually, but not required.

Rob

Re: [PATCH v6 1/3] dt-bindings: hwmon: fan: Add fan binding to schema

[Krzysztof Kozlowski]

On 16/11/2022 22:36, Naresh Solanki wrote:
> Add common fan properties bindings to a schema.
> 
> Bindings for fan controllers can reference the common schema for the
> fan
> 
> child nodes:
> 
>   patternProperties:
>     "^fan@[0-2]":
>       type: object
>       $ref: fan-common.yaml#
> 
> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> ---
>  .../devicetree/bindings/hwmon/fan-common.yaml | 42 +++++++++++++++++++
>  1 file changed, 42 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> new file mode 100644
> index 000000000000..1954882eed77
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> @@ -0,0 +1,42 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Common fan properties

If there is going to be resend - capitalize title, so:

Common Fan Properties

> +
> +maintainers:
> +  - Naresh Solanki <naresh.solanki@9elements.com>
> +
> +properties:
> +  max-rpm:
> +    description:
> +      Max RPM supported by fan.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  pulses-per-revolution:
> +    description:
> +      The number of pulse from fan sensor per revolution.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  target-rpm:
> +    description:
> +      Target RPM the fan should be configured during driver probe.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  pwms:
> +    description:
> +      PWM provider.

Isn't this object? If so, maybe:
  type: object



Best regards,
Krzysztof

Re: [PATCH v6 1/3] dt-bindings: hwmon: fan: Add fan binding to schema

[Naresh Solanki]

Hi Krzysztof,

On 29-11-2022 01:38 pm, Krzysztof Kozlowski wrote:
> On 16/11/2022 22:36, Naresh Solanki wrote:
>> Add common fan properties bindings to a schema.
>>
>> Bindings for fan controllers can reference the common schema for the
>> fan
>>
>> child nodes:
>>
>>    patternProperties:
>>      "^fan@[0-2]":
>>        type: object
>>        $ref: fan-common.yaml#
>>
>> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
>> ---
>>   .../devicetree/bindings/hwmon/fan-common.yaml | 42 +++++++++++++++++++
>>   1 file changed, 42 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
>> new file mode 100644
>> index 000000000000..1954882eed77
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
>> @@ -0,0 +1,42 @@
>> +# SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Common fan properties
> 
> If there is going to be resend - capitalize title, so:
> 
> Common Fan Properties
> 
Sure
>> +
>> +maintainers:
>> +  - Naresh Solanki <naresh.solanki@9elements.com>
>> +
>> +properties:
>> +  max-rpm:
>> +    description:
>> +      Max RPM supported by fan.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +
>> +  pulses-per-revolution:
>> +    description:
>> +      The number of pulse from fan sensor per revolution.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +
>> +  target-rpm:
>> +    description:
>> +      Target RPM the fan should be configured during driver probe.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +
>> +  pwms:
>> +    description:
>> +      PWM provider.
> 
> Isn't this object? If so, maybe:
>    type: object
With make dt_binding_check, I'm getting error for this.
Looking at other available examples in documentation, type object is not 
used.

Example:
   pwms:
     maxItems: 1

One pwm per fan.
> 
> 
> 
> Best regards,
> Krzysztof
> 
Regards,
Naresh