| Message ID | 1483608344-9012-4-git-send-email-benjamin.gaignard@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Jan 05, 2017 at 10:25:39AM +0100, Benjamin Gaignard wrote: > Define bindings for pwm-stm32 > > version 6: > - change st,breakinput parameter format to make it usuable on stm32f7 too. > > 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 | 33 ++++++++++++++++++++++ > 1 file changed, 33 insertions(+) > create mode 100644 Documentation/devicetree/bindings/pwm/pwm-stm32.txt Acked-by: Rob Herring <robh@kernel.org>
On Thu, Jan 05, 2017 at 10:25:39AM +0100, Benjamin Gaignard wrote: > Define bindings for pwm-stm32 > > version 6: > - change st,breakinput parameter format to make it usuable on stm32f7 too. > > 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 | 33 ++++++++++++++++++++++ > 1 file changed, 33 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..866f222 > --- /dev/null > +++ b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt > @@ -0,0 +1,33 @@ > +STMicroelectronics STM32 Timers PWM bindings > + > +Must be a sub-node of an STM32 Timers device tree node. > +See ../mfd/stm32-timers.txt for details about the parent node. > + > +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 see ../pinctrl/pinctrl-bindings.txt > + > +Optional parameters: > +- st,breakinput: Arrays of three u32 <index level filter> to describe break input configurations. > + "index" indicates on which break input the configuration should be applied. It might be useful to specify what the valid values are for the break input index. Also, u32 is kind of a Linuxism, perhaps "Arrays of three cells"? Also, does this mean there can be multiple entries? Such as 6 cells for two configurations? What's the maximum number of such configurations? If it's possible to specify multiple configurations, maybe a slightly clearer wording would be: "One or more <index level filter> triplets to describe..." > + "level" gives the active level (0=low or 1=high) for this configuration. So how does this work exactly? "level" specifies the output level if the filter value is matched? > + "filter" gives the filtering value to be applied. Is this a single value at which "level" will be applied? Or is it an upper/lower bound that can be used to restrict the output to "level" if the signal goes beyond/below a certain threshold? Maybe an example would clarify this. Or perhaps a reference to a manual where a more in-depth description of this functionality can be found. Thierry
2017-01-18 10:20 GMT+01:00 Thierry Reding <thierry.reding@gmail.com>: > On Thu, Jan 05, 2017 at 10:25:39AM +0100, Benjamin Gaignard wrote: >> Define bindings for pwm-stm32 >> >> version 6: >> - change st,breakinput parameter format to make it usuable on stm32f7 too. >> >> 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 | 33 ++++++++++++++++++++++ >> 1 file changed, 33 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..866f222 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt >> @@ -0,0 +1,33 @@ >> +STMicroelectronics STM32 Timers PWM bindings >> + >> +Must be a sub-node of an STM32 Timers device tree node. >> +See ../mfd/stm32-timers.txt for details about the parent node. >> + >> +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 see ../pinctrl/pinctrl-bindings.txt >> + >> +Optional parameters: >> +- st,breakinput: Arrays of three u32 <index level filter> to describe break input configurations. >> + "index" indicates on which break input the configuration should be applied. > > It might be useful to specify what the valid values are for the break > input index. It could 0 and 1, I will add this information. > > Also, u32 is kind of a Linuxism, perhaps "Arrays of three cells"? Also, > does this mean there can be multiple entries? Such as 6 cells for two > configurations? What's the maximum number of such configurations? > > If it's possible to specify multiple configurations, maybe a slightly > clearer wording would be: "One or more <index level filter> triplets to > describe..." > You can have one configuration per index so I will rephrase it like that: One or two <index level filter> to describe break input configurations. "index" indicates on which break input (0 or 1 ) the configuration should be applied. >> + "level" gives the active level (0=low or 1=high) for this configuration. > > So how does this work exactly? "level" specifies the output level if the > filter value is matched? No it specify on which input level the break event is generated > >> + "filter" gives the filtering value to be applied. > > Is this a single value at which "level" will be applied? Or is it an > upper/lower bound that can be used to restrict the output to "level" if > the signal goes beyond/below a certain threshold? Very very basically filter is more a debounce value set on the signal to avoid glitches. The goal of break input feature is to stop PWM generation in hardware errors failure case. For a more completed description you can read "using break input function" (starting page 645) in this doc: http://www.st.com/content/ccc/resource/technical/document/reference_manual/c5/cf/ef/52/c0/f1/4b/fa/DM00124865.pdf/files/DM00124865.pdf/jcr:content/translations/en.DM00124865.pdf > > Maybe an example would clarify this. Or perhaps a reference to a manual > where a more in-depth description of this functionality can be found. > > Thierry
diff --git a/Documentation/devicetree/bindings/pwm/pwm-stm32.txt b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt new file mode 100644 index 0000000..866f222 --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt @@ -0,0 +1,33 @@ +STMicroelectronics STM32 Timers PWM bindings + +Must be a sub-node of an STM32 Timers device tree node. +See ../mfd/stm32-timers.txt for details about the parent node. + +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 see ../pinctrl/pinctrl-bindings.txt + +Optional parameters: +- st,breakinput: Arrays of three u32 <index level filter> to describe break input configurations. + "index" indicates on which break input the configuration should be applied. + "level" gives the active level (0=low or 1=high) for this configuration. + "filter" gives the filtering value to be applied. + +Example: + timers@40010000 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "st,stm32-timers"; + reg = <0x40010000 0x400>; + clocks = <&rcc 0 160>; + clock-names = "clk_int"; + + pwm { + compatible = "st,stm32-pwm"; + pinctrl-0 = <&pwm1_pins>; + pinctrl-names = "default"; + st,breakinput = <0 1 5>; + }; + };
Define bindings for pwm-stm32 version 6: - change st,breakinput parameter format to make it usuable on stm32f7 too. 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 | 33 ++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 Documentation/devicetree/bindings/pwm/pwm-stm32.txt