On 11/17/18 7:29 AM, Rob Herring wrote:
On Fri, Nov 09, 2018 at 11:56:06AM +1300, 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>
---
Changes in v2:
- use pwm-polarity attiribute to indicate normal or inverted polarity.
.../devicetree/bindings/hwmon/adt7475.txt | 24 +++++++++++++++++++
.../devicetree/bindings/trivial-devices.txt | 4 ----
2 files changed, 24 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..d9212b5e9036
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/adt7475.txt
@@ -0,0 +1,24 @@
+*ADT7475 hwmon sensor.
+
+Required properties:
+- compatible: One of
+ "adi,adt7473"
+ "adi,adt7475"
+ "adi,adt7476"
+ "adi,adt7490"
+
+- reg: I2C address
+
+optional properties:
+
+- pwm-polarity: This configures the polarity of the PWM. 0
+ (PWM_POLARITY_NORMAL) uses logic high for 100% duty cycle. 1
+ (PWM_POLARITY_INVERSED) uses logic low for 100% duty cycle.
So we're using part of the PWM binding, but none of the rest of it? What
is the PWM connection here?
The chip has a built-in PWM controller to control fan speeds. PWM frequency
as well as PWM polarity are configurable. I had suggested to use the terminology
from Documentation/devicetree/bindings/pwm/pwm.txt. Other than terminology there
is no connection to a standard pwm controller.
Another option/possibility would be to use a boolean, such as pwm-polarity-inverted.
We are open to suggestions.
It sounds like this is common for sensors, so this should be documented
somewhere common.
Sure, no problem. Any suggestion where ?
Thanks,
Guenter
