On Mon, Dec 05, 2016 at 01:12:25PM +0100, Benjamin Gaignard wrote:
2016-12-05 12:23 GMT+01:00 Thierry Reding thierry.reding@gmail.com:
On Mon, Dec 05, 2016 at 12:08:32PM +0100, Benjamin Gaignard wrote:
2016-12-05 7:53 GMT+01:00 Thierry Reding thierry.reding@gmail.com:
On Fri, Dec 02, 2016 at 11:17:18AM +0100, Benjamin Gaignard wrote:
Define bindings for pwm-stm32
version 2:
- use parameters instead of compatible of handle the hardware configuration
Signed-off-by: Benjamin Gaignard benjamin.gaignard@st.com
.../devicetree/bindings/pwm/pwm-stm32.txt | 38 ++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 Documentation/devicetree/bindings/pwm/pwm-stm32.txt
diff --git a/Documentation/devicetree/bindings/pwm/pwm-stm32.txt b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt new file mode 100644 index 0000000..575b9fb --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt @@ -0,0 +1,38 @@ +STMicroelectronics PWM driver bindings for STM32
Technically this bindings describe devices, so "driver binding" is a somewhat odd wording. Perhaps:
STMicroelectronics STM32 General Purpose Timer PWM bindings?
done
+Must be a sub-node of STM32 general purpose timer driver +Parent node properties are describe in ../mfd/stm32-general-purpose-timer.txt
Again, "driver parent node" is odd. Perhaps:
Must be a sub-node of an STM32 General Purpose Timer device tree node. See ../mfd/stm32-general-purpose-timer.txt for details about the parent node.?
done
+Required parameters: +- compatible: Must be "st,stm32-pwm" +- pinctrl-names: Set to "default". +- pinctrl-0: List of phandles pointing to pin configuration nodes
for PWM module.For Pinctrl properties, please refer to [1].Your indentation and capitalization are inconsistent. Also, please refer to the pinctrl bindings by relative path and inline, rather than as a footnote reference.
OK
+Optional parameters: +- st,breakinput: Set if the hardware have break input capabilities +- st,breakinput-polarity: Set break input polarity. Default is 0
The value define the active polarity:- 0 (active LOW)- 1 (active HIGH)Could we fold these into a single property? If st,breakinput-polarity is not present it could simply mean that there is no break input, and if it is present you don't have to rely on a default.
I need to know if I have to activate breakinput feature and on which level I will rewrite it like that: Optional parameters:
- st,breakinput-polarity-high: Set if break input polarity is active
on high level.
- st,breakinput-polarity-high: Set if break input polarity is active
on low level.
How is that different from a single property:
Optional properties: - st,breakinput-polarity: If present, a break input is available for the channel. In that case the property value denotes the polarity of the break input: - 0: active low - 1: active high?
For break input feature I need two information: do I have to active it and if activated on which level. I have two solutions:
- one parameter with a value (0 or 1) -> st,breakinput-polarity
- two parameters without value -> st,breakinput-active-high and
st,breakinput-active-low
By default break input feature is disabled
Right, what I was suggesting is that you use the first solution because it's the typical way to use for tristate options. It's also much easier to test for in practice because for the second solution you have to parse two properties before you know whether it is active or not.
The second is typically the solution for required properties where only one of the properties is used to override the default.
Thierry