On 11/6/18 8:27 PM, Chris Packham wrote:
On 7/11/18 5:24 PM, Guenter Roeck wrote:
On 11/6/18 8:00 PM, Chris Packham wrote:
With the addition of the invert-pwm property the adt7475 needs its own
binding documentation rather being captured under trivial-devices.txt.
Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
---
.../devicetree/bindings/hwmon/adt7475.txt | 22 +++++++++++++++++++
.../devicetree/bindings/trivial-devices.txt | 4 ----
2 files changed, 22 insertions(+), 4 deletions(-)
create mode 100644 Documentation/devicetree/bindings/hwmon/adt7475.txt
diff --git a/Documentation/devicetree/bindings/hwmon/adt7475.txt b/Documentation/devicetree/bindings/hwmon/adt7475.txt
new file mode 100644
index 000000000000..79255439e157
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/adt7475.txt
@@ -0,0 +1,22 @@
+*ADT7475 hwmon sensor.
+
+Required properties:
+- compatible: One of
+ "adi,adt7473"
+ "adi,adt7475"
+ "adi,adt7476"
+ "adi,adt7490"
+
+- reg: I2C address
+
+optional properties:
+
+- invert-pwm: This configures the PWM to use logic low for 100% duty cycle.
+
+Example:
+
+hwmon@2e {
+ compatible = ;
+ reg = <0x2e>;
+ invert-pwm;
If I understand correctly, the flag is set per pwm channel. A single global
property seems inappropriate.
Yes it is per-channel. But I was having a hard time imagining a hardware
design that would use both inverted and non-inverted at the same time.
People can be inventive. Sometimes too much so.
Do you have a preference for how the properties should look?
invert-pwm[123]?
invert-pwm = <0x7>;?
Ultimately we'll have to find a generic way of defining devicetree properties for
hardware monitoring devices, not just for pwm but for all sensor types. A sub-node
per channel seems to be the most likely answer, but I think that is a long way off
(and will require lengthy discussions about acceptable properties).
I was looking into pwm DT properties, but they define a set of flags
(PWM_POLARITY_INVERTED, PWM_POLARITY_NORMAL).
The g762 driver uses "pwm_polarity". Underscore - hmm. Other drivers use module
parameters, sysfs attributes (pwmX_invert in asc7621 driver), or platform data
(g762, max6639).
Maybe pwm-polarity = <PWM_POLARITY_NORMAL | PWM_POLARITY_INVERTED> ?
No idea if that makes sense. Or just a boolean pwm-polarity-inverted.
Thinking about it per channel vs. per chip ... other drivers also seem to
use a single property / attribute for the entire chip, so that is fine here
as well. We can always extend it if needed.
Anyway, I am fine with whatever Rob accepts.
Guenter
Guenter
+};
diff --git a/Documentation/devicetree/bindings/trivial-devices.txt b/Documentation/devicetree/bindings/trivial-devices.txt
index 69c934aec13b..4f29100d6bbf 100644
--- a/Documentation/devicetree/bindings/trivial-devices.txt
+++ b/Documentation/devicetree/bindings/trivial-devices.txt
@@ -14,10 +14,6 @@ ad,ad7414 SMBus/I2C Digital Temperature Sensor in 6-Pin SOT with SMBus Alert an
ad,adm9240 ADM9240: Complete System Hardware Monitor for uProcessor-Based Systems
adi,adt7461 +/-1C TDM Extended Temp Range I.C
adt7461 +/-1C TDM Extended Temp Range I.C
-adi,adt7473 +/-1C TDM Extended Temp Range I.C
-adi,adt7475 +/-1C TDM Extended Temp Range I.C
-adi,adt7476 +/-1C TDM Extended Temp Range I.C
-adi,adt7490 +/-1C TDM Extended Temp Range I.C
adi,adxl345 Three-Axis Digital Accelerometer
adi,adxl346 Three-Axis Digital Accelerometer (backward-compatibility value "adi,adxl345" must be listed too)
ams,iaq-core AMS iAQ-Core VOC Sensor
