On Tue, Dec 22, 2015 at 06:51:18PM -0600, Rob Herring wrote:

On Mon, Dec 21, 2015 at 10:24:08AM +0100, Ludovic Desroches wrote:

quoted

This driver supports the new version of the Atmel ADC device introduced
with the SAMA5D2 SoC family.

Signed-off-by: Ludovic Desroches <redacted>
---
 .../devicetree/bindings/iio/adc/at91_adc8xx.txt    |  27 ++
 drivers/iio/adc/Kconfig                            |  11 +
 drivers/iio/adc/Makefile                           |   1 +
 drivers/iio/adc/at91_adc8xx.c                      | 417 +++++++++++++++++++++
 4 files changed, 456 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/at91_adc8xx.txt
 create mode 100644 drivers/iio/adc/at91_adc8xx.c

diff --git a/Documentation/devicetree/bindings/iio/adc/at91_adc8xx.txt b/Documentation/devicetree/bindings/iio/adc/at91_adc8xx.txt
new file mode 100644
index 0000000..64ad6a5
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/at91_adc8xx.txt

@@ -0,0 +1,27 @@
+* AT91 SAMA5D2 Analog to Digital Converter (ADC)
+
+Required properties:
+  - compatible: Should be "atmel,sama5d2-adc".
+  - reg: Should contain ADC registers location and length.
+  - interrupts: Should contain the IRQ line for the ADC.
+  - clocks: phandles to clocks.
+  - clock-names: tuple listing clock names.
+      Required elements: "adc_clk", "adc_op_clk". "adc_clk" is the peripheral
+      clock, "adc_clk" is the sampling clock.
+  - vref-supply: Supply used as reference for conversions.
+
+Optional properties:
+  - vddana-supply: Supply for the adc device.

What makes a supply optional? If chip dependent, then then you need a 
more specific compatible string.

I thought I had read that we can supply an external vddana or having a
default one. Double checking the datasheet. I can't find it, I probably
read it on a draft version. Will move the vddana supply to required
properties.

Thanks

Ludovic