Add the max31790 driver binding document and support pwmout-pin-as-tach-input
property for the max31790 driver.
Chanh Nguyen (3):
dt-bindings: hwmon: Add maxim max31790 driver bindings
hwmon: (max31790): Support config PWM output becomes TACH
dt-bindings: hwmon: max31790: Add pwmout-pin-as-tach-input property
.../devicetree/bindings/hwmon/max31790.yaml | 55 +++++++++++++++++++
drivers/hwmon/max31790.c | 31 +++++++++++
2 files changed, 86 insertions(+)
create mode 100644 Documentation/devicetree/bindings/hwmon/max31790.yaml
--
2.17.1
Add a device tree bindings for max31790 device.
Signed-off-by: Chanh Nguyen <[email protected]>
---
.../devicetree/bindings/hwmon/max31790.yaml | 44 +++++++++++++++++++
1 file changed, 44 insertions(+)
create mode 100644 Documentation/devicetree/bindings/hwmon/max31790.yaml
diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
new file mode 100644
index 000000000000..5a93e6bdebda
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
@@ -0,0 +1,44 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/max31790.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: The Maxim MAX31790 Fan Controller
+
+maintainers:
+ - Jean Delvare <[email protected]>
+ - Guenter Roeck <[email protected]>
+
+description: >
+ The MAX31790 controls the speeds of up to six fans using six
+ independent PWM outputs. The desired fan speeds (or PWM duty cycles)
+ are written through the I2C interface.
+
+ Datasheets:
+ https://datasheets.maximintegrated.com/en/ds/MAX31790.pdf
+
+properties:
+ compatible:
+ const: maxim,max31790
+
+ reg:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+
+additionalProperties: false
+
+examples:
+ - |
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ max31790@20 {
+ compatible = "maxim,max31790";
+ reg = <0x20>;
+ };
+ };
--
2.17.1
PWMOUT pins on MAX31790 can be configured as a tachometer input pin by
setting bit[0] in the Configuration Register. When the bit[0] of a channel
is set, the PWMOUT pin becomes the tach input pin for the channel plus six.
This commit allows the kernel to set those pins when necessary if the
pwmout-pin-as-tach-input DT property exists.
Signed-off-by: Chanh Nguyen <[email protected]>
---
drivers/hwmon/max31790.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
index 3dc95196b229..33ca8d1721c0 100644
--- a/drivers/hwmon/max31790.c
+++ b/drivers/hwmon/max31790.c
@@ -12,6 +12,7 @@
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/module.h>
+#include <linux/property.h>
#include <linux/slab.h>
/* MAX31790 registers */
@@ -506,9 +507,12 @@ static int max31790_probe(struct i2c_client *client)
{
struct i2c_adapter *adapter = client->adapter;
struct device *dev = &client->dev;
+ u8 pwmout_to_tach[NR_CHANNEL];
struct max31790_data *data;
struct device *hwmon_dev;
int err;
+ u8 tmp;
+ int i;
if (!i2c_check_functionality(adapter,
I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
@@ -528,6 +532,33 @@ static int max31790_probe(struct i2c_client *client)
if (err)
return err;
+ if (device_property_present(dev, "pwmout-pin-as-tach-input")) {
+ err = device_property_read_u8_array(dev, "pwmout-pin-as-tach-input",
+ pwmout_to_tach, NR_CHANNEL);
+ if (err) {
+ /* The pwmout-pin-as-tach-input is an array of six values */
+ dev_warn(dev, "The pwmout-pin-as-tach-input property exist but malform");
+ } else {
+ for (i = 0; i < NR_CHANNEL; i++) {
+ tmp = data->fan_config[i];
+ if (pwmout_to_tach[i])
+ data->fan_config[i] |= MAX31790_FAN_CFG_TACH_INPUT;
+ else
+ data->fan_config[i] &= ~(MAX31790_FAN_CFG_TACH_INPUT);
+
+ if (tmp != data->fan_config[i]) {
+ err = i2c_smbus_write_byte_data(client,
+ MAX31790_REG_FAN_CONFIG(i),
+ data->fan_config[i]);
+ if (err < 0)
+ dev_warn(dev,
+ "Fail to apply fan configuration at channel %d",
+ i);
+ }
+ }
+ }
+ }
+
hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
data,
&max31790_chip_info,
--
2.17.1
Add pwmout-pin-as-tach-input property.
Signed-off-by: Chanh Nguyen <[email protected]>
---
Documentation/devicetree/bindings/hwmon/max31790.yaml | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
index 5a93e6bdebda..447cac17053a 100644
--- a/Documentation/devicetree/bindings/hwmon/max31790.yaml
+++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
@@ -25,6 +25,16 @@ properties:
reg:
maxItems: 1
+ pwmout-pin-as-tach-input:
+ description: |
+ An array of six integers responds to six PWM channels for
+ configuring the pwm to tach mode.
+ When set to 0, the associated PWMOUT produces a PWM waveform for
+ control of fan speed. When set to 1, PWMOUT becomes a TACH input
+ $ref: /schemas/types.yaml#/definitions/uint8-array
+ maxItems: 6
+ minItems: 6
+
required:
- compatible
- reg
@@ -40,5 +50,6 @@ examples:
max31790@20 {
compatible = "maxim,max31790";
reg = <0x20>;
+ pwmout-pin-as-tach-input = /bits/ 8 <0 0 0 0 1 1>;
};
};
--
2.17.1
On 11/03/2024 12:13, Chanh Nguyen wrote:
> Add a device tree bindings for max31790 device.
Subject: drop "driver", bindings are about hardware.
It does not look like you tested the bindings, at least after quick
look. Please run `make dt_binding_check` (see
Documentation/devicetree/bindings/writing-schema.rst for instructions).
Maybe you need to update your dtschema and yamllint.
>
> Signed-off-by: Chanh Nguyen <[email protected]>
> ---
> .../devicetree/bindings/hwmon/max31790.yaml | 44 +++++++++++++++++++
> 1 file changed, 44 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/hwmon/max31790.yaml
>
> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
> new file mode 100644
> index 000000000000..5a93e6bdebda
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
Filename like compatible.
> @@ -0,0 +1,44 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/max31790.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: The Maxim MAX31790 Fan Controller
> +
> +maintainers:
> + - Jean Delvare <[email protected]>
> + - Guenter Roeck <[email protected]>
You should have here someone responsible for hardware, not subsystem
maintainers.
> +
> +description: >
> + The MAX31790 controls the speeds of up to six fans using six
> + independent PWM outputs. The desired fan speeds (or PWM duty cycles)
> + are written through the I2C interface.
> +
> + Datasheets:
> + https://datasheets.maximintegrated.com/en/ds/MAX31790.pdf
> +
> +properties:
> + compatible:
> + const: maxim,max31790
> +
> + reg:
> + maxItems: 1
That's weirdly empty.
> +
> +required:
> + - compatible
> + - reg
> +
You miss allOf: with $ref to fan controller schema.
> +additionalProperties: false
> +
> +examples:
> + - |
> + i2c {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + max31790@20 {
Node names should be generic. See also an explanation and list of
examples (not exhaustive) in DT specification:
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
Best regards,
Krzysztof
On 11/03/2024 12:13, Chanh Nguyen wrote:
> Add pwmout-pin-as-tach-input property.
Why is this split from original binding? This does not make much
sense... Add complete hardware description.
>
> Signed-off-by: Chanh Nguyen <[email protected]>
> ---
> Documentation/devicetree/bindings/hwmon/max31790.yaml | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
> index 5a93e6bdebda..447cac17053a 100644
> --- a/Documentation/devicetree/bindings/hwmon/max31790.yaml
> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
> @@ -25,6 +25,16 @@ properties:
> reg:
> maxItems: 1
>
> + pwmout-pin-as-tach-input:
> + description: |
> + An array of six integers responds to six PWM channels for
> + configuring the pwm to tach mode.
> + When set to 0, the associated PWMOUT produces a PWM waveform for
> + control of fan speed. When set to 1, PWMOUT becomes a TACH input
No vendor prefix, so generic property... but where is it defined?
Best regards,
Krzysztof
On Mon, Mar 11, 2024 at 06:13:47PM +0700, Chanh Nguyen wrote:
> Add pwmout-pin-as-tach-input property.
>
> Signed-off-by: Chanh Nguyen <[email protected]>
> ---
> Documentation/devicetree/bindings/hwmon/max31790.yaml | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
> index 5a93e6bdebda..447cac17053a 100644
> --- a/Documentation/devicetree/bindings/hwmon/max31790.yaml
> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
> @@ -25,6 +25,16 @@ properties:
> reg:
> maxItems: 1
>
> + pwmout-pin-as-tach-input:
> + description: |
> + An array of six integers responds to six PWM channels for
> + configuring the pwm to tach mode.
> + When set to 0, the associated PWMOUT produces a PWM waveform for
> + control of fan speed. When set to 1, PWMOUT becomes a TACH input
> + $ref: /schemas/types.yaml#/definitions/uint8-array
> + maxItems: 6
> + minItems: 6
Seems incomplete. For example, fan tachs have different number of
pulses per revolution, don't you need to know that too?
There's a common fan binding now (or pending). You should use that and
this property won't be needed.
Rob
On 3/11/24 10:34, Rob Herring wrote:
> On Mon, Mar 11, 2024 at 06:13:47PM +0700, Chanh Nguyen wrote:
>> Add pwmout-pin-as-tach-input property.
>>
>> Signed-off-by: Chanh Nguyen <[email protected]>
>> ---
>> Documentation/devicetree/bindings/hwmon/max31790.yaml | 11 +++++++++++
>> 1 file changed, 11 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>> index 5a93e6bdebda..447cac17053a 100644
>> --- a/Documentation/devicetree/bindings/hwmon/max31790.yaml
>> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>> @@ -25,6 +25,16 @@ properties:
>> reg:
>> maxItems: 1
>>
>> + pwmout-pin-as-tach-input:
>> + description: |
>> + An array of six integers responds to six PWM channels for
>> + configuring the pwm to tach mode.
>> + When set to 0, the associated PWMOUT produces a PWM waveform for
>> + control of fan speed. When set to 1, PWMOUT becomes a TACH input
>> + $ref: /schemas/types.yaml#/definitions/uint8-array
>> + maxItems: 6
>> + minItems: 6
>
> Seems incomplete. For example, fan tachs have different number of
> pulses per revolution, don't you need to know that too?
>
Per Documentation/ABI/testing/sysfs-class-hwmon:
What: /sys/class/hwmon/hwmonX/fanY_pulses
Description:
Number of tachometer pulses per fan revolution.
Integer value, typically between 1 and 4.
RW
This value is a characteristic of the fan connected to the
device's input, so it has to be set in accordance with the fan
model.
Should only be created if the chip has a register to configure
the number of pulses. In the absence of such a register (and
thus attribute) the value assumed by all devices is 2 pulses
per fan revolution.
We only expect the property (and attribute) to exist if the controller
supports it.
Guenter
On 11/03/2024 23:56, Krzysztof Kozlowski wrote:
> On 11/03/2024 12:13, Chanh Nguyen wrote:
>> Add pwmout-pin-as-tach-input property.
>
> Why is this split from original binding? This does not make much
> sense... Add complete hardware description.
>
Ok Krzysztof, I will merg the "[PATCH 1/3] dt-bindings: hwmon: Add maxim
max31790 driver bindings" commit and "[PATCH 3/3] dt-bindings: hwmon:
max31790: Add pwmout-pin-as-tach-input property" commit.
>>
>> Signed-off-by: Chanh Nguyen <[email protected]>
>> ---
>> Documentation/devicetree/bindings/hwmon/max31790.yaml | 11 +++++++++++
>> 1 file changed, 11 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>> index 5a93e6bdebda..447cac17053a 100644
>> --- a/Documentation/devicetree/bindings/hwmon/max31790.yaml
>> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>> @@ -25,6 +25,16 @@ properties:
>> reg:
>> maxItems: 1
>>
>> + pwmout-pin-as-tach-input:
>> + description: |
>> + An array of six integers responds to six PWM channels for
>> + configuring the pwm to tach mode.
>> + When set to 0, the associated PWMOUT produces a PWM waveform for
>> + control of fan speed. When set to 1, PWMOUT becomes a TACH input
>
> No vendor prefix, so generic property... but where is it defined?
>
Thank Krzysztof! It is not generic property, I'll add the vendor prefix.
I'll update the "pwmout-pin-as-tach-input" to
"maxim,pwmout-pin-as-tach-input" at v2.
>
> Best regards,
> Krzysztof
>
On 11/03/2024 23:55, Krzysztof Kozlowski wrote:
> On 11/03/2024 12:13, Chanh Nguyen wrote:
>> Add a device tree bindings for max31790 device.
>
> Subject: drop "driver", bindings are about hardware.
>
Yes, I'll drop "driver" at v2 updating.
> It does not look like you tested the bindings, at least after quick
> look. Please run `make dt_binding_check` (see
> Documentation/devicetree/bindings/writing-schema.rst for instructions).
> Maybe you need to update your dtschema and yamllint.
>
I tested the binding, I didn't see any warning/error log. Please review
my logs as below
=> make dt_binding_check DT_SCHEMA_FILES=/hwmon/max31790.yaml
make[1]: Entering directory '/DISK4T/work/community/linux/out'
DTEX Documentation/devicetree/bindings/hwmon/max31790.example.dts
DTC_CHK Documentation/devicetree/bindings/hwmon/max31790.example.dtb
make[1]: Leaving directory '/DISK4T/work/community/linux/out'
>>
>> Signed-off-by: Chanh Nguyen <[email protected]>
>> ---
>> .../devicetree/bindings/hwmon/max31790.yaml | 44 +++++++++++++++++++
>> 1 file changed, 44 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/hwmon/max31790.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>> new file mode 100644
>> index 000000000000..5a93e6bdebda
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>
> Filename like compatible.
Yes, I'll update that in v2
>
>> @@ -0,0 +1,44 @@
>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/hwmon/max31790.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: The Maxim MAX31790 Fan Controller
>> +
>> +maintainers:
>> + - Jean Delvare <[email protected]>
>> + - Guenter Roeck <[email protected]>
>
> You should have here someone responsible for hardware, not subsystem
> maintainers.
>
Hi Krzysztof,
I checked the history of the drivers/hwmon/max31790.c and see Guenter
Roeck <[email protected]> as an important maintainer. I saw many
commits from him. So, I add him to maintainer list.
>> +
>> +description: >
>> + The MAX31790 controls the speeds of up to six fans using six
>> + independent PWM outputs. The desired fan speeds (or PWM duty cycles)
>> + are written through the I2C interface.
>> +
>> + Datasheets:
>> + https://datasheets.maximintegrated.com/en/ds/MAX31790.pdf
>> +
>> +properties:
>> + compatible:
>> + const: maxim,max31790
>> +
>> + reg:
>> + maxItems: 1
>
> That's weirdly empty.
>
Hi Krzysztof,
I have not yet understood your comment here. Please help give more
details for my missing! Thank Krzysztof!
>> +
>> +required:
>> + - compatible
>> + - reg
>> +
>
> You miss allOf: with $ref to fan controller schema.
>
Thank Krzysztof,
I'll add the allOf at v2.
>> +additionalProperties: false
>> +
>> +examples:
>> + - |
>> + i2c {
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> +
>> + max31790@20 {
>
> Node names should be generic. See also an explanation and list of
> examples (not exhaustive) in DT specification:
> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
>
I suggest some node names, such as "i2c-fan" or "fan-controller" . Can
you please share your ideas with me!
>
> Best regards,
> Krzysztof
>
On 12/03/2024 00:34, Rob Herring wrote:
> On Mon, Mar 11, 2024 at 06:13:47PM +0700, Chanh Nguyen wrote:
>> Add pwmout-pin-as-tach-input property.
>>
>> Signed-off-by: Chanh Nguyen <[email protected]>
>> ---
>> Documentation/devicetree/bindings/hwmon/max31790.yaml | 11 +++++++++++
>> 1 file changed, 11 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>> index 5a93e6bdebda..447cac17053a 100644
>> --- a/Documentation/devicetree/bindings/hwmon/max31790.yaml
>> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>> @@ -25,6 +25,16 @@ properties:
>> reg:
>> maxItems: 1
>>
>> + pwmout-pin-as-tach-input:
>> + description: |
>> + An array of six integers responds to six PWM channels for
>> + configuring the pwm to tach mode.
>> + When set to 0, the associated PWMOUT produces a PWM waveform for
>> + control of fan speed. When set to 1, PWMOUT becomes a TACH input
>> + $ref: /schemas/types.yaml#/definitions/uint8-array
>> + maxItems: 6
>> + minItems: 6
>
> Seems incomplete. For example, fan tachs have different number of
> pulses per revolution, don't you need to know that too?
>
> There's a common fan binding now (or pending). You should use that and
> this property won't be needed.
>
> Rob
Thank Rob,
I checked in the
Documentation/devicetree/bindings/hwmon/fan-common.yaml. I found the
tach-ch property, but it seems define the tach channel used for fan.
tach-ch:
description:
The tach channel used for the fan.
$ref: /schemas/types.yaml#/definitions/uint8-array
I would like to define a new vendor property to configure the PWM-OUT
pin to become a TACH-IN pin. So I introduce the
"maxim,pwmout-pin-as-tach-input" property. Please help me share your
comments!
On 12/03/2024 00:52, Guenter Roeck wrote:
> On 3/11/24 10:34, Rob Herring wrote:
>> On Mon, Mar 11, 2024 at 06:13:47PM +0700, Chanh Nguyen wrote:
>>> Add pwmout-pin-as-tach-input property.
>>>
>>> Signed-off-by: Chanh Nguyen <[email protected]>
>>> ---
>>> Documentation/devicetree/bindings/hwmon/max31790.yaml | 11 +++++++++++
>>> 1 file changed, 11 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>> b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>> index 5a93e6bdebda..447cac17053a 100644
>>> --- a/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>> @@ -25,6 +25,16 @@ properties:
>>> reg:
>>> maxItems: 1
>>> + pwmout-pin-as-tach-input:
>>> + description: |
>>> + An array of six integers responds to six PWM channels for
>>> + configuring the pwm to tach mode.
>>> + When set to 0, the associated PWMOUT produces a PWM waveform for
>>> + control of fan speed. When set to 1, PWMOUT becomes a TACH input
>>> + $ref: /schemas/types.yaml#/definitions/uint8-array
>>> + maxItems: 6
>>> + minItems: 6
>>
>> Seems incomplete. For example, fan tachs have different number of
>> pulses per revolution, don't you need to know that too?
>>
>
> Per Documentation/ABI/testing/sysfs-class-hwmon:
>
> What: /sys/class/hwmon/hwmonX/fanY_pulses
> Description:
> Number of tachometer pulses per fan revolution.
>
> Integer value, typically between 1 and 4.
>
> RW
>
> This value is a characteristic of the fan connected to the
> device's input, so it has to be set in accordance with
> the fan
> model.
>
> Should only be created if the chip has a register to
> configure
> the number of pulses. In the absence of such a register
> (and
> thus attribute) the value assumed by all devices is 2
> pulses
> per fan revolution.
>
> We only expect the property (and attribute) to exist if the controller
> supports it.
>
> Guenter
>
Hi Guenter and Rob,
Most general-purpose brushless DC fans produce two tachometer pulses per
revolution. My fan devices also produce two tachometer pulses per
revolution.
In max31790.c, I saw the formula that is used to calculate TACH Count
Registers, which defines the pulses per revolution as 2
#define RPM_TO_REG(rpm, sr) ((60 * (sr) * 8192) / ((rpm) * 2))
Do you think we should support the pulses-per-revolution property in
this case?
On 18/03/2024 10:51, Chanh Nguyen wrote:
>
>> It does not look like you tested the bindings, at least after quick
>> look. Please run `make dt_binding_check` (see
>> Documentation/devicetree/bindings/writing-schema.rst for instructions).
>> Maybe you need to update your dtschema and yamllint.
>>
>
>
> I tested the binding, I didn't see any warning/error log. Please review
> my logs as below
Hm, I don't remember what brought my attention to possible error. Maybe
I mistyped my template.
>
> => make dt_binding_check DT_SCHEMA_FILES=/hwmon/max31790.yaml
> make[1]: Entering directory '/DISK4T/work/community/linux/out'
> DTEX Documentation/devicetree/bindings/hwmon/max31790.example.dts
> DTC_CHK Documentation/devicetree/bindings/hwmon/max31790.example.dtb
> make[1]: Leaving directory '/DISK4T/work/community/linux/out'
>
>>>
>>> Signed-off-by: Chanh Nguyen <[email protected]>
>>> ---
>>> .../devicetree/bindings/hwmon/max31790.yaml | 44 +++++++++++++++++++
>>> 1 file changed, 44 insertions(+)
>>> create mode 100644 Documentation/devicetree/bindings/hwmon/max31790.yaml
>>>
>>> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>> new file mode 100644
>>> index 000000000000..5a93e6bdebda
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>
>> Filename like compatible.
>
> Yes, I'll update that in v2
>
>>
>>> @@ -0,0 +1,44 @@
>>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
>>> +%YAML 1.2
>>> +---
>>> +$id: http://devicetree.org/schemas/hwmon/max31790.yaml#
>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>> +
>>> +title: The Maxim MAX31790 Fan Controller
>>> +
>>> +maintainers:
>>> + - Jean Delvare <[email protected]>
>>> + - Guenter Roeck <[email protected]>
>>
>> You should have here someone responsible for hardware, not subsystem
>> maintainers.
>>
>
> Hi Krzysztof,
> I checked the history of the drivers/hwmon/max31790.c and see Guenter
> Roeck <[email protected]> as an important maintainer. I saw many
> commits from him. So, I add him to maintainer list.
OK
>
>>> +
>>> +description: >
>>> + The MAX31790 controls the speeds of up to six fans using six
>>> + independent PWM outputs. The desired fan speeds (or PWM duty cycles)
>>> + are written through the I2C interface.
>>> +
>>> + Datasheets:
>>> + https://datasheets.maximintegrated.com/en/ds/MAX31790.pdf
>>> +
>>> +properties:
>>> + compatible:
>>> + const: maxim,max31790
>>> +
>>> + reg:
>>> + maxItems: 1
>>
>> That's weirdly empty.
>>
>
> Hi Krzysztof,
> I have not yet understood your comment here. Please help give more
> details for my missing! Thank Krzysztof!
I expect many more properties of a fan controller. Resources (clocks,
PWMs, supplies) and FAN specific properties.
>>> +
>>> +required:
>>> + - compatible
>>> + - reg
>>> +
>>
>> You miss allOf: with $ref to fan controller schema.
>>
>
> Thank Krzysztof,
> I'll add the allOf at v2.
>
>>> +additionalProperties: false
>>> +
>>> +examples:
>>> + - |
>>> + i2c {
>>> + #address-cells = <1>;
>>> + #size-cells = <0>;
>>> +
>>> + max31790@20 {
>>
>> Node names should be generic. See also an explanation and list of
>> examples (not exhaustive) in DT specification:
>> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
>>
>
> I suggest some node names, such as "i2c-fan" or "fan-controller" . Can
> you please share your ideas with me!
Look at recent commits and patches for similar type of a device.
Best regards,
Krzysztof
On 18/03/2024 10:48, Chanh Nguyen wrote:
>
>
> On 11/03/2024 23:56, Krzysztof Kozlowski wrote:
>> On 11/03/2024 12:13, Chanh Nguyen wrote:
>>> Add pwmout-pin-as-tach-input property.
>>
>> Why is this split from original binding? This does not make much
>> sense... Add complete hardware description.
>>
>
> Ok Krzysztof, I will merg the "[PATCH 1/3] dt-bindings: hwmon: Add maxim
> max31790 driver bindings" commit and "[PATCH 3/3] dt-bindings: hwmon:
> max31790: Add pwmout-pin-as-tach-input property" commit.
Later I checked your driver code and this explains a bit. However first
patch should explain that instead. The split is fine, but just lack of
rationale is confusing.
>
>>>
>>> Signed-off-by: Chanh Nguyen <[email protected]>
>>> ---
>>> Documentation/devicetree/bindings/hwmon/max31790.yaml | 11 +++++++++++
>>> 1 file changed, 11 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>> index 5a93e6bdebda..447cac17053a 100644
>>> --- a/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>> @@ -25,6 +25,16 @@ properties:
>>> reg:
>>> maxItems: 1
>>>
>>> + pwmout-pin-as-tach-input:
>>> + description: |
>>> + An array of six integers responds to six PWM channels for
>>> + configuring the pwm to tach mode.
>>> + When set to 0, the associated PWMOUT produces a PWM waveform for
>>> + control of fan speed. When set to 1, PWMOUT becomes a TACH input
>>
>> No vendor prefix, so generic property... but where is it defined?
>>
>
> Thank Krzysztof! It is not generic property, I'll add the vendor prefix.
>
> I'll update the "pwmout-pin-as-tach-input" to
> "maxim,pwmout-pin-as-tach-input" at v2.
Except that you should really look into common properties and use them.
Or explain why do you need new property?
Best regards,
Krzysztof
On 18/03/2024 17:02, Krzysztof Kozlowski wrote:
> On 18/03/2024 10:48, Chanh Nguyen wrote:
>>
>>
>> On 11/03/2024 23:56, Krzysztof Kozlowski wrote:
>>> On 11/03/2024 12:13, Chanh Nguyen wrote:
>>>> Add pwmout-pin-as-tach-input property.
>>>
>>> Why is this split from original binding? This does not make much
>>> sense... Add complete hardware description.
>>>
>>
>> Ok Krzysztof, I will merg the "[PATCH 1/3] dt-bindings: hwmon: Add maxim
>> max31790 driver bindings" commit and "[PATCH 3/3] dt-bindings: hwmon:
>> max31790: Add pwmout-pin-as-tach-input property" commit.
>
> Later I checked your driver code and this explains a bit. However first
> patch should explain that instead. The split is fine, but just lack of
> rationale is confusing.
>
Thank Krzysztof. I'll try to explain in detail each patch in v2.
>
>>
>>>>
>>>> Signed-off-by: Chanh Nguyen <[email protected]>
>>>> ---
>>>> Documentation/devicetree/bindings/hwmon/max31790.yaml | 11 +++++++++++
>>>> 1 file changed, 11 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>>> index 5a93e6bdebda..447cac17053a 100644
>>>> --- a/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>>> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>>> @@ -25,6 +25,16 @@ properties:
>>>> reg:
>>>> maxItems: 1
>>>>
>>>> + pwmout-pin-as-tach-input:
>>>> + description: |
>>>> + An array of six integers responds to six PWM channels for
>>>> + configuring the pwm to tach mode.
>>>> + When set to 0, the associated PWMOUT produces a PWM waveform for
>>>> + control of fan speed. When set to 1, PWMOUT becomes a TACH input
>>>
>>> No vendor prefix, so generic property... but where is it defined?
>>>
>>
>> Thank Krzysztof! It is not generic property, I'll add the vendor prefix.
>>
>> I'll update the "pwmout-pin-as-tach-input" to
>> "maxim,pwmout-pin-as-tach-input" at v2.
>
> Except that you should really look into common properties and use them.
> Or explain why do you need new property?
>
> Best regards,
> Krzysztof
>
I'm also discussing with Rob Herring that on patch 3/3, I checked in the
Documentation/devicetree/bindings/hwmon/fan-common.yaml. I found the
tach-ch property, but it seems to define the tach channel used for the
fan. It does not match my purpose. I want to configure the PWM-OUT pin
to become a TACH-IN pin. I wonder if I can use the tach-ch property for
my purpose.
On 18/03/2024 17:00, Krzysztof Kozlowski wrote:
> On 18/03/2024 10:51, Chanh Nguyen wrote:
>>
>>> It does not look like you tested the bindings, at least after quick
>>> look. Please run `make dt_binding_check` (see
>>> Documentation/devicetree/bindings/writing-schema.rst for instructions).
>>> Maybe you need to update your dtschema and yamllint.
>>>
>>
>>
>> I tested the binding, I didn't see any warning/error log. Please review
>> my logs as below
>
> Hm, I don't remember what brought my attention to possible error. Maybe
> I mistyped my template.
>
>>
>> => make dt_binding_check DT_SCHEMA_FILES=/hwmon/max31790.yaml
>> make[1]: Entering directory '/DISK4T/work/community/linux/out'
>> DTEX Documentation/devicetree/bindings/hwmon/max31790.example.dts
>> DTC_CHK Documentation/devicetree/bindings/hwmon/max31790.example.dtb
>> make[1]: Leaving directory '/DISK4T/work/community/linux/out'
>>
>>>>
>>>> Signed-off-by: Chanh Nguyen <[email protected]>
>>>> ---
>>>> .../devicetree/bindings/hwmon/max31790.yaml | 44 +++++++++++++++++++
>>>> 1 file changed, 44 insertions(+)
>>>> create mode 100644 Documentation/devicetree/bindings/hwmon/max31790.yaml
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>>> new file mode 100644
>>>> index 000000000000..5a93e6bdebda
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>>
>>> Filename like compatible.
>>
>> Yes, I'll update that in v2
>>
>>>
>>>> @@ -0,0 +1,44 @@
>>>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
>>>> +%YAML 1.2
>>>> +---
>>>> +$id: http://devicetree.org/schemas/hwmon/max31790.yaml#
>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>>> +
>>>> +title: The Maxim MAX31790 Fan Controller
>>>> +
>>>> +maintainers:
>>>> + - Jean Delvare <[email protected]>
>>>> + - Guenter Roeck <[email protected]>
>>>
>>> You should have here someone responsible for hardware, not subsystem
>>> maintainers.
>>>
>>
>> Hi Krzysztof,
>> I checked the history of the drivers/hwmon/max31790.c and see Guenter
>> Roeck <[email protected]> as an important maintainer. I saw many
>> commits from him. So, I add him to maintainer list.
>
> OK
>
>>
>>>> +
>>>> +description: >
>>>> + The MAX31790 controls the speeds of up to six fans using six
>>>> + independent PWM outputs. The desired fan speeds (or PWM duty cycles)
>>>> + are written through the I2C interface.
>>>> +
>>>> + Datasheets:
>>>> + https://datasheets.maximintegrated.com/en/ds/MAX31790.pdf
>>>> +
>>>> +properties:
>>>> + compatible:
>>>> + const: maxim,max31790
>>>> +
>>>> + reg:
>>>> + maxItems: 1
>>>
>>> That's weirdly empty.
>>>
>>
>> Hi Krzysztof,
>> I have not yet understood your comment here. Please help give more
>> details for my missing! Thank Krzysztof!
>
> I expect many more properties of a fan controller. Resources (clocks,
> PWMs, supplies) and FAN specific properties.
>
Hi Krzysztof,
I'm creating a base binding document for the max31790 driver. I'm basing
it on the drivers/hwmon/max31790.c. Currently, the max31790.c driver has
not yet implemented other properties, such as clocks, fan-supply, pwms,
etc. So I just introduced the "compatible" and "reg" properties.
In the near future, if any other properties are necessary, I think we
will implement them in drivers/hwmon/max31790.c then update this binding
document.
I look at other binding documents, I also see something similar. They
just introduce the "compatible" and "reg" properties.
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/devicetree/bindings/hwmon/adi,max31760.yaml
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/devicetree/bindings/hwmon/adt7475.yaml
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/devicetree/bindings/hwmon/adi,ad741x.yaml
This is only my view. It's a pleasure to hear your advice. Thanks!
>
>>>> +
>>>> +required:
>>>> + - compatible
>>>> + - reg
>>>> +
>>>
>>> You miss allOf: with $ref to fan controller schema.
>>>
>>
>> Thank Krzysztof,
>> I'll add the allOf at v2.
>>
>>>> +additionalProperties: false
>>>> +
>>>> +examples:
>>>> + - |
>>>> + i2c {
>>>> + #address-cells = <1>;
>>>> + #size-cells = <0>;
>>>> +
>>>> + max31790@20 {
>>>
>>> Node names should be generic. See also an explanation and list of
>>> examples (not exhaustive) in DT specification:
>>> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
>>>
>>
>> I suggest some node names, such as "i2c-fan" or "fan-controller" . Can
>> you please share your ideas with me!
>
> Look at recent commits and patches for similar type of a device.
>
Hi Krzysztof,
I checked on recent commits and found something of a similar type.
adi,max31760.yaml
fan-controller@50 {
reg = <0x50>;
compatible = "adi,max31760";
};
hpe,gxp-fan-ctrl.yaml
fan-controller@1000c00 {
compatible = "hpe,gxp-fan-ctrl";
reg = <0x1000c00 0x200>, <0xd1000000 0xff>, <0x80200000 0x100000>;
reg-names = "base", "pl", "fn2";
};
adi,axi-fan-control.yaml
axi_fan_control: axi-fan-control@80000000 {
compatible = "adi,axi-fan-control-1.00.a";
reg = <0x0 0x80000000 0x10000>;
clocks = <&clk 71>;
interrupts = <0 110 0>;
pulses-per-revolution = <2>;
};
I think "fan-controller" is a good node name. Do you think so?
> Best regards,
> Krzysztof
>
On 22/03/2024 10:53, Chanh Nguyen wrote:
>>>>
>>>
>>> Hi Krzysztof,
>>> I have not yet understood your comment here. Please help give more
>>> details for my missing! Thank Krzysztof!
>>
>> I expect many more properties of a fan controller. Resources (clocks,
>> PWMs, supplies) and FAN specific properties.
>>
>
> Hi Krzysztof,
>
> I'm creating a base binding document for the max31790 driver. I'm basing
> it on the drivers/hwmon/max31790.c. Currently, the max31790.c driver has
Binding should be based on device (e.g. its datasheet), not the driver.
> not yet implemented other properties, such as clocks, fan-supply, pwms,
> etc. So I just introduced the "compatible" and "reg" properties.
>
> In the near future, if any other properties are necessary, I think we
> will implement them in drivers/hwmon/max31790.c then update this binding
> document.
Please instead read:
Documentation/devicetree/bindings/writing-bindings.rst
>
> I look at other binding documents, I also see something similar. They
> just introduce the "compatible" and "reg" properties.
>
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/devicetree/bindings/hwmon/adi,max31760.yaml
Maybe these devices are similar, maybe not. This should not be excuse to
come with really incomplete binding.
..
> I think "fan-controller" is a good node name. Do you think so?
>
Yes.
Best regards,
Krzysztof
On 25/03/2024 15:32, Krzysztof Kozlowski wrote:
> On 22/03/2024 10:53, Chanh Nguyen wrote:
>>>>>
>>>>
>>>> Hi Krzysztof,
>>>> I have not yet understood your comment here. Please help give more
>>>> details for my missing! Thank Krzysztof!
>>>
>>> I expect many more properties of a fan controller. Resources (clocks,
>>> PWMs, supplies) and FAN specific properties.
>>>
>>
>> Hi Krzysztof,
>>
>> I'm creating a base binding document for the max31790 driver. I'm basing
>> it on the drivers/hwmon/max31790.c. Currently, the max31790.c driver has
>
> Binding should be based on device (e.g. its datasheet), not the driver.
>
Thank Krzysztof,
I'm reading the writing-bindings.rst and I got it for now. I'll make
complete binding in patch v2.
I am very pleased to hear your comments.
>> not yet implemented other properties, such as clocks, fan-supply, pwms,
>> etc. So I just introduced the "compatible" and "reg" properties.
>>
>> In the near future, if any other properties are necessary, I think we
>> will implement them in drivers/hwmon/max31790.c then update this binding
>> document.
>
> Please instead read:
> Documentation/devicetree/bindings/writing-bindings.rst
>
>>
>> I look at other binding documents, I also see something similar. They
>> just introduce the "compatible" and "reg" properties.
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/devicetree/bindings/hwmon/adi,max31760.yaml
>
> Maybe these devices are similar, maybe not. This should not be excuse to
> come with really incomplete binding.
>
> ...
>
>> I think "fan-controller" is a good node name. Do you think so?
>>
>
> Yes.
>
> Best regards,
> Krzysztof
>
On 18/03/2024 16:53, Chanh Nguyen wrote:
>
>
> On 12/03/2024 00:34, Rob Herring wrote:
>> On Mon, Mar 11, 2024 at 06:13:47PM +0700, Chanh Nguyen wrote:
>>> Add pwmout-pin-as-tach-input property.
>>>
>>> Signed-off-by: Chanh Nguyen <[email protected]>
>>> ---
>>> Documentation/devicetree/bindings/hwmon/max31790.yaml | 11 +++++++++++
>>> 1 file changed, 11 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>> b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>> index 5a93e6bdebda..447cac17053a 100644
>>> --- a/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
>>> @@ -25,6 +25,16 @@ properties:
>>> reg:
>>> maxItems: 1
>>> + pwmout-pin-as-tach-input:
>>> + description: |
>>> + An array of six integers responds to six PWM channels for
>>> + configuring the pwm to tach mode.
>>> + When set to 0, the associated PWMOUT produces a PWM waveform for
>>> + control of fan speed. When set to 1, PWMOUT becomes a TACH input
>>> + $ref: /schemas/types.yaml#/definitions/uint8-array
>>> + maxItems: 6
>>> + minItems: 6
>>
>> Seems incomplete. For example, fan tachs have different number of
>> pulses per revolution, don't you need to know that too?
>>
>> There's a common fan binding now (or pending). You should use that and
>> this property won't be needed.
>>
>> Rob
>
> Thank Rob,
>
> I checked in the
> Documentation/devicetree/bindings/hwmon/fan-common.yaml. I found the
> tach-ch property, but it seems define the tach channel used for fan.
>
> tach-ch:
> description:
> The tach channel used for the fan.
> $ref: /schemas/types.yaml#/definitions/uint8-array
>
> I would like to define a new vendor property to configure the PWM-OUT
> pin to become a TACH-IN pin. So I introduce the
> "maxim,pwmout-pin-as-tach-input" property. Please help me share your
> comments!
Hi Guenter and Rob,
I'm preparing for patch v2. I'm looking forward to hear your advice.
Should I use the "tach-ch" property (a common fan property) or define
new vendor property ("maxim,pwmout-pin-as-tach-input") for my purpose?
Thank you very much!
Chanh