On Mon, Jan 23, 2017 at 05:32:19PM +0100, Arnaud Pouliquen wrote:
Add bindings information for STM32 Digital Filter for Sigma Delta modulators MFD driver
Signed-off-by: Arnaud Pouliquen arnaud.pouliquen@st.com
.../devicetree/bindings/mfd/stm32-dfsdm.txt | 68 ++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 Documentation/devicetree/bindings/mfd/stm32-dfsdm.txt
diff --git a/Documentation/devicetree/bindings/mfd/stm32-dfsdm.txt b/Documentation/devicetree/bindings/mfd/stm32-dfsdm.txt new file mode 100644 index 0000000..e0b45ee --- /dev/null +++ b/Documentation/devicetree/bindings/mfd/stm32-dfsdm.txt @@ -0,0 +1,68 @@ +STMicroelectronics STM32 Digital Filter for Sigma Delta Modulator (DFSDM) +ulti-function device.
+The STM32 DFSDM device is a multifunction device that handles the DFSDM IP.
+The DFSDM IP allows to add processing on Sigma Delta ADC based on SinC filters. +For this, a pool of m filters can be connected to a pool of n channels. +For STM32H7 : m = 4, n = 8.
+Each channel n is assigned to the SPI or Manchester interface n or n + 1. +Channels 0 to 2 can also be connected to ADC IP instance 1 to 3. +Filtering result is stored in a left aligned register, with 8 LSB reserved for +the input channel ID.
+Each filter instance supports two contexts to manage conversions, each one has +its own configurable sequence and trigger: +- regular conversion: used for single or continuous conversion. +- injected conversions: used for triggered conversion.
+Interfaces supported: +- sigma delta ADCs trough IIO framework. +- PDM microphones through ASoC framework.
Bindings describe h/w, not Linux subsystems.
+Required properties: +- compatible: Must be "st,stm32h7-dfsdm". +- reg: Specifies the DFSDM block register address and length. +- interrupts: IRQ lines connected to each DFSDM filter instance. +- clocks: IP and serial interfaces clocking. Should be set according
to rcc clock ID and "clock-names".+- clock-names: Input clock name "dfsdm_clk" must be defined,
"audio_clk" is optional. If defined CLKOUT is based on the audioclock, else "dfsdm_clk" is used.
_clk is redundant.
+Optional properties: +- st,clkout-freq: clkout clock frequency (Hz).This clock must be set according
to "clock" property. Frequency must be a multiple of the rccclock frequency. If not, clkout frequency will not beaccurate.
What is CLKOUT connected to and will you need to describe that in DT?
+- pinctrl-names: set to "default". +- pinctrl-0: List of phandles pointing to pin configuration nodes for DFSDM
module.For Pinctrl properties see ../pinctrl/pinctrl-bindings.txt+Example :
- dfsdm: dfsdm@4400D000 {
compatible = "st,stm32h7-dfsdm";reg = <0x40017000 0x400>;interrupts = <110>, <111>, <112>, <113>;clocks = <&timer_clk>;clock-names = "dfsdm_clk";pinctrl-0 = <&dfsdm_ch0 &dfsdm_ch1>;pinctrl-names = "default";st,clkout-freq = <2480000>;iio_dfsdm0: iio-dfsdm@0 {
adc {
compatible = "st,stm32-dfsdm-adc";#io-channel-cells = <1>;reg = <0>;status = "disabled";};dai_dfsdm0: dfsdm-audio@0 {
digital-mic {
compatible = "st,stm32-dfsdm-audio";#sound-dai-cells = <0>;reg = <0>;
You can't have 2 children with the same unit address. Just drop reg and the unit address.
dmas = <&dmamux1 101 0x400 0x00>;dma-names = "rx";status = "disabled";};- };
-- 1.9.1