Merge tag 'staging-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging/IIO driver updates from Greg KH:
 "Here is the big staging and iio driver pull request for 4.21-rc1.

  Lots and lots of tiny patches here, nothing major at all. Which is
  good, tiny cleanups is nice to see. No new huge driver removal or
  addition, this release cycle, although there are lots of good IIO
  driver changes, addtions, and movement from staging into the "real"
  part of the kernel, which is always great.

  Full details are in the shortlog, and all of these have been in
  linux-next for a while with no reported issues"

* tag 'staging-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (553 commits)
  staging: mt7621-mmc: Correct spelling mistakes in comments
  staging: wilc1000: fix missing read_write setting when reading data
  mt7621-mmc: char * array declaration might be better as static const
  mt7621-mmc: return statement in void function unnecessary
  mt7621-mmc: Alignment should match open parenthesis
  mt7621-mmc: Removed unnecessary blank lines
  mt7621-mmc: Fix some coding style issues
  staging: android: ashmem: doc: Fix spelling
  staging: rtl8188eu: cleanup brace coding style issues
  staging: rtl8188eu: add spaces around '&' in rtw_mlme_ext.c
  staging: rtl8188eu: change return type of is_basicrate() to bool
  staging: rtl8188eu: simplify null array initializations
  staging: rtl8188eu: change order of declarations to improve readability
  staging: rtl8188eu: make some arrays static in rtw_mlme_ext.c
  staging: rtl8188eu: constify some arrays
  staging: rtl8188eu: convert unsigned char arrays to u8
  staging: rtl8188eu: remove redundant declaration in rtw_mlme_ext.c
  staging: rtl8188eu: remove unused arrays WFD_OUI and WMM_INFO_OUI
  staging: rtl8188eu: remove unnecessary parentheses in rtw_mlme_ext.c
  staging: rtl8188eu: remove unnecessary comments in rtw_mlme_ext.c
  ...

1 files changed, 31 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/iio/resolver/ad2s90.txt b/Documentation/devicetree/bindings/iio/resolver/ad2s90.txt
new file mode 100644
index 000000000000..477d41fa6467
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/resolver/ad2s90.txt
@@ -0,0 +1,31 @@
+Analog Devices AD2S90 Resolver-to-Digital Converter
+
+https://www.analog.com/en/products/ad2s90.html
+
+Required properties:
+  - compatible: should be "adi,ad2s90"
+  - reg: SPI chip select number for the device
+  - spi-max-frequency: set maximum clock frequency, must be 830000
+  - spi-cpol and spi-cpha:
+        Either SPI mode (0,0) or (1,1) must be used, so specify none or both of
+        spi-cpha, spi-cpol.
+
+See for more details:
+    Documentation/devicetree/bindings/spi/spi-bus.txt
+
+Note about max frequency:
+    Chip's max frequency, as specified in its datasheet, is 2Mhz. But a 600ns
+    delay is expected between the application of a logic LO to CS and the
+    application of SCLK, as also specified. And since the delay is not
+    implemented in the spi code, to satisfy it, SCLK's period should be at most
+    2 * 600ns, so the max frequency should be 1 / (2 * 6e-7), which gives
+    roughly 830000Hz.
+
+Example:
+resolver@0 {
+	compatible = "adi,ad2s90";
+	reg = <0>;
+	spi-max-frequency = <830000>;
+	spi-cpol;
+	spi-cpha;
+};