Messages in this thread | | | Subject | Re: [PATCH 01/10] Documentation: dt-bindings: Document STM32 ADC DT bindings | From | Fabrice Gasnier <> | Date | Thu, 3 Nov 2016 12:11:19 +0100 |
| |
On 10/31/2016 04:02 AM, Rob Herring wrote: > On Tue, Oct 25, 2016 at 06:25:13PM +0200, Fabrice Gasnier wrote: >> This patch adds documentation of device tree bindings for the STM32 ADC. >> >> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> >> --- >> .../devicetree/bindings/iio/adc/st,stm32-adc.txt | 78 ++++++++++++++++++++++ >> 1 file changed, 78 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt >> >> diff --git a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt >> new file mode 100644 >> index 0000000..a9a8b3c >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt >> @@ -0,0 +1,78 @@ >> +STMicroelectronics STM32 ADC device driver >> + >> +STM32 ADC is a successive approximation analog-to-digital converter. >> +It has several multiplexed input channels. Conversions can be performed >> +in single, continuous, scan or discontinuous mode. Result of the ADC is >> +stored in a left-aligned or right-aligned 32-bit data register. >> +Conversions can be launched in software or using hardware triggers. >> + >> +The analog watchdog feature allows the application to detect if the input >> +voltage goes beyond the user-defined, higher or lower thresholds. >> + >> +Each STM32 ADC block can have up to 3 ADC instances. >> + >> +Each instance supports two contexts to manage conversions, each one has its >> +own configurable sequence and trigger: >> +- regular conversion can be done in sequence, running in background >> +- injected conversions have higher priority, and so have the ability to >> + interrupt regular conversion sequence (either triggered in SW or HW). >> + Regular sequence is resumed, in case it has been interrupted. >> + >> +Required properties: >> +- compatible: Should be "st,stm32f4-adc". >> +- reg: Offset and length of the ADC block register set. >> +- interrupts: Must contain the interrupt for ADC. >> +- clocks: Clock for the analog circuitry (common to all ADCs). >> +- clock-names: Must be "adc". >> +- vref-supply: Phandle to the vref input analog reference voltage. >> +- #address-cells = <1>; >> +- #size-cells = <0>; >> + >> +Optional properties: >> +- A pinctrl state named "default" for each ADC channel may be defined to set >> + inX ADC pins in mode of operation for analog input on external pin. >> +- gpios: Array of gpios that may be configured as EXTi trigger sources. >> + >> +Example: > This should be last. Hi Rob,
I'll fix this. > >> + adc: adc@40012000 { >> + compatible = "st,stm32f4-adc"; >> + reg = <0x40012000 0x400>; >> + interrupts = <18>; >> + clocks = <&rcc 0 168>; >> + clock-names = "adc"; >> + vref-supply = <®_vref>; >> + pinctrl-names = "default"; >> + pinctrl-0 = <&adc3_in8_pin>; >> + gpios = <&gpioa 11 0>, >> + <&gpioa 15 0>; >> + >> + #address-cells = <1>; >> + #size-cells = <0>; >> + >> + adc1: adc1-master@0 { > adc@0 sufficient? Yes, if you agree, I'd go for adc1@0, adc2@100, adc3@200, to reflect reg property for child node. Is it ok from your point of view ?
> >> + #io-channel-cells = <1>; >> + reg = <0x0>; >> + clocks = <&rcc 0 168>; >> + st,adc-channels = <8>; >> + }; >> + ... >> + other adc child nodes follow... >> + }; >> + >> +Contents of a stm32 adc child node: >> +----------------------------------- >> +An ADC block node should contain at least one subnode, representing an >> +ADC instance available on the machine. >> + >> +Required properties: >> +- reg: Offset of ADC instance in ADC block (e.g. may be 0x0, 0x100, 0x200). >> +- st,adc-channels: List of single-ended channels muxed for this ADC. > How many? What are valid values? stm32f4 can have up to 19 channels, numbered from 0 to 18 to match with reference manual. I'll add this. > >> +- #io-channel-cells = <1>: See the IIO bindings section "IIO consumers" in >> + Documentation/devicetree/bindings/iio/iio-bindings.txt >> + >> +Optional properties: >> +- clocks: Input clock private to this ADC instance. >> +- st,injected: Use injected conversion sequence on an ADC, rather than regular. > Not sure about this one. Seems like this would either be a user choice > or depend on what's connected to the ADC. It's related to ADC sequencer, and the way it's being configured/used (see above paragraph on regular/injected). This is not related to what's connected to adc inputs. As suggested by Jonathan, I think I'll drop injected support for now, to simplify the driver and review.
Thanks, Best Regards, Fabrice > >> +- dmas: Phandle to dma channel for this ADC instance, only for regular >> + conversions. See ../../dma/dma.txt for details. >> +- dma-names: Must be "rx" when dmas property is being used. >> -- >> 1.9.1 >>
| |