Add DT bindings for the Renesas RCar GyroADC block. This block is
a simple 4/8-channel ADC which samples 12/15/24 bits of data every
cycle from all channels.
Signed-off-by: Marek Vasut <marek.vasut@xxxxxxxxx>
Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Cc: Simon Horman <horms+renesas@xxxxxxxxxxxx>
Cc: Jonathan Cameron <jic23@xxxxxxxxxx>
Cc: linux-renesas-soc@xxxxxxxxxxxxxxx
Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: devicetree@xxxxxxxxxxxxxxx
---
V8: - Sync the version with the 2/2 driver patch
- Drop status prop from example
- Add GyroADC block description
- Enumerate the compatible string values
- Make subnodes mandatory
---
.../bindings/iio/adc/renesas,gyroadc.txt | 99 ++++++++++++++++++++++
1 file changed, 99 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/renesas,gyroadc.txt
diff --git a/Documentation/devicetree/bindings/iio/adc/renesas,gyroadc.txt b/Documentation/devicetree/bindings/iio/adc/renesas,gyroadc.txt
new file mode 100644
index 000000000000..7f9b3bd120a9
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/renesas,gyroadc.txt
@@ -0,0 +1,99 @@
+* Renesas RCar GyroADC device driver
+
+The GyroADC block is a reduced SPI block with up to 8 chipselect lines,
+which supports the SPI protocol of a selected few SPI ADCs. The SPI ADCs
+are sampled by the GyroADC block in a round-robin fashion and the result
+presented in the GyroADC registers.
+
+Required properties:
+- compatible: Should be "<soc-specific>", "renesas,rcar-gyroadc".
+ The <soc-specific> should be one of:
+ renesas,r8a7791-gyroadc - for the GyroADC block present
+ in r8a7791 SoC
+ renesas,r8a7792-gyroadc - for the GyroADC with interrupt
+ block present in r8a7792 SoC
+- reg: Address and length of the register set for the device
+- clocks: References to all the clocks specified in the clock-names
+ property as specified in
+ Documentation/devicetree/bindings/clock/clock-bindings.txt.
+- clock-names: Shall contain "fck" and "if". The "fck" is the GyroADC block
+ clock, the "if" is the interface clock.
+- power-domains: Must contain a reference to the PM domain, if available.
+- #address-cells: Should be <1> (setting for the subnodes) for all ADCs
+ except for "fujitsu,mb88101a". Should be <0> (setting for
+ only subnode) for "fujitsu,mb88101a".
+- #size-cells: Should be <0> (setting for the subnodes)
+
+Sub-nodes:
+You must define subnode(s) which select the connected ADC type and reference
+voltage for the GyroADC channels.
+
+Required properties for subnodes:
+- compatible: Should be either of:
+ "fujitsu,mb88101a"
+ - Fujitsu MB88101A compatible mode,
+ 12bit sampling, up to 4 channels can be sampled in
+ round-robin fashion. One Fujitsu chip supplies four
+ GyroADC channels with data as it contains four ADCs
+ on the chip and thus for 4-channel operation, single
+ MB88101A is required. The Cx chipselect lines of the
+ MB88101A connect directly to two CHS lines of the
+ GyroADC, no demuxer is required. The data out line
+ of each MB88101A connects to a shared input pin of
+ the GyroADC.
+ "ti,adcs7476" or "ti,adc121" or "adi,ad7476"
+ - TI ADCS7476 / TI ADC121 / ADI AD7476 compatible mode,
+ 15bit sampling, up to 8 channels can be sampled in
+ round-robin fashion. One TI/ADI chip supplies single
+ ADC channel with data, thus for 8-channel operation,
+ 8 chips are required. A 3:8 chipselect demuxer is
+ required to connect the nCS line of the TI/ADI chips
+ to the GyroADC, while MISO line of each TI/ADI ADC
+ connects to a shared input pin of the GyroADC.
+ "maxim,max1162" or "maxim,max11100"
+ - Maxim MAX1162 / Maxim MAX11100 compatible mode,
+ 16bit sampling, up to 8 channels can be sampled in
+ round-robin fashion. One Maxim chip supplies single
+ ADC channel with data, thus for 8-channel operation,
+ 8 chips are required. A 3:8 chipselect demuxer is
+ required to connect the nCS line of the MAX chips
+ to the GyroADC, while MISO line of each Maxim ADC
+ connects to a shared input pin of the GyroADC.
+- reg: Should be the number of the analog input. Should be present
+ for all ADCs except "fujitsu,mb88101a".
+- vref-supply: Reference to the channel reference voltage regulator.
+
+Example:
+ vref_max1162: regulator-vref-max1162 {
+ compatible = "regulator-fixed";
+
+ regulator-name = "MAX1162 Vref";
+ regulator-min-microvolt = <4096000>;
+ regulator-max-microvolt = <4096000>;
+ };
+
+ &adc {
+ compatible = "renesas,r8a7791-gyroadc", "renesas,rcar-gyroadc";
+ reg = <0 0xe6e54000 0 64>;
+ clocks = <&mstp9_clks R8A7791_CLK_GYROADC>, <&clk_65m>;
+ clock-names = "fck", "if";
+ power-domains = <&sysc R8A7791_PD_ALWAYS_ON>;
+
+ pinctrl-0 = <&adc_pins>;
+ pinctrl-names = "default";
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ adc@0 {
+ reg = <0>;
+ compatible = "maxim,max1162";
+ vref-supply = <&vref_max1162>;
+ };
+
+ adc@1 {
+ reg = <1>;
+ compatible = "maxim,max1162";
+ vref-supply = <&vref_max1162>;
+ };
+ };
--
2.11.0
