On 31/03/17 12:45, Fabrice Gasnier wrote: > Document STMicroelectronics STM32 DAC (digital-to-analog converter). > > Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx> > --- > .../devicetree/bindings/iio/dac/st,stm32-dac.txt | 56 ++++++++++++++++++++++ > 1 file changed, 56 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/dac/st,stm32-dac.txt > > diff --git a/Documentation/devicetree/bindings/iio/dac/st,stm32-dac.txt b/Documentation/devicetree/bindings/iio/dac/st,stm32-dac.txt > new file mode 100644 > index 0000000..1981983 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/dac/st,stm32-dac.txt > @@ -0,0 +1,56 @@ > +STMicroelectronics STM32 DAC > + > +The STM32 DAC is a 12-bit voltage output digital-to-analog converter. The DAC > +can be configured in 8- or 12-bit mode. In 12-bit mode, the data could be > +left- or right-aligned. Whilst possibly true, do we care about the alignment? That'll all get wrapped up in the driver. > It has two output channels, each with its own converter. > +It has built-in noise and triangle waveform generator and supports external > +triggers for conversions. The DAC's output buffer allows a high drive output > +current. Ah.. This is going to be fun :) More unusual hardware to find in an SoC. > + > +Contents of a stm32 dac root node: > +----------------------------------- > +Required properties: > +- compatible: Must be "st,stm32h7-dac-core". > +- reg: Offset and length of the device's register set. > +- clocks: Must contain an entry for pclk (which feeds the peripheral bus > + interface) > +- clock-names: Must be "pclk". > +- vref-supply: Phandle to the vref+ input analog reference supply. > + > +Optional properties: > +- resets: Must contain the phandle to the reset controller. > +- A pinctrl state named "default" for each DAC channel may be defined to set > + DAC_OUTx pin in mode of operation for analog output on external pin. > + > +Contents of a stm32 dac child node: > +----------------------------------- > +DAC core node should contain at least one subnode, representing a > +DAC instance/channel available on the machine. > + > +Required properties: > +- compatible: Must be "st,stm32-dac". > +- #io-channel-cells = <1>: See the IIO bindings section "IIO consumers" in > + Documentation/devicetree/bindings/iio/iio-bindings.txt > +- st,dac-channel: Must be either 1 or 2, to define channel in use (e.g. > + single channels: 1 or 2) > + > +Example: > + dac: dac@40007400 { > + compatible = "st,stm32h7-dac-core"; > + reg = <0x40007400 0x400>; > + clocks = <&clk>; > + clock-names = "pclk"; > + vref-supply = <®_vref>; > + > + dac1: dac@1 { > + compatible = "st,stm32-dac"; > + #io-channels-cells = <1>; > + st,dac-channel = <1>; > + }; > + > + dac2: dac@2 { > + compatible = "st,stm32-dac"; > + #io-channels-cells = <1>; > + st,dac-channel = <2>; > + }; > + }; > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html