Merge tag 'spi-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "Quite a quiet release for SPI, there are no changes at all to the core
  and not that many changes to drivers. Highlights of those driver
  changes include:

   - SH MSIOF support for GPIO chip selects contributed by Geert
     Uytterhoeven.

   - Full duplex support for a3700 contributed by Maxime Chevallier.

   - Support for DMA transfers on Atmel devices that require a bounce
     buffer contributed by Radu Pirea"

* tag 'spi-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (31 commits)
  spi: dw: Remove unused members from struct chip_data
  spi: orion: Fix a resource leak if the optional "axi" clk is deferred
  spi: a3700: Remove endianness swapping for full-duplex transfers
  spi: a3700: Remove endianness swapping functions when accessing FIFOs
  spi: a3700: Add full-duplex support
  spi: a3700: Allow to enable or disable FIFO mode
  spi: a3700: Set frequency limits at startup
  spi: a3700: Clear DATA_OUT when performing a read
  spi: orion: Fix clock resource by adding an optional bus clock
  spi: s3c64xx: add SPDX identifier
  spi: imx: do not access registers while clocks disabled
  spi: atmel: Implements transfers with bounce buffer
  spi: sh-msiof: Fix timeout failures for TX-only DMA transfers
  spi: spi-fsl-dspi: account for const type of of_device_id.data
  spi: bcm53xx: simplify reading SPI data
  spi: sirf: account for const type of of_device_id.data
  spi: pxa2xx: Use gpiod_put() not gpiod_free()
  spi: pxa2xx: avoid redundant gpio_to_desc(desc_to_gpio()) round-trip
  spi: sh-msiof: Document hardware limitations related to chip selects
  spi: sh-msiof: Implement cs-gpios configuration
  ...

1 files changed, 15 insertions, 1 deletions

diff --git a/Documentation/devicetree/bindings/spi/sh-msiof.txt b/Documentation/devicetree/bindings/spi/sh-msiof.txt
index bdd83959019c..80710f0f0448 100644
--- a/Documentation/devicetree/bindings/spi/sh-msiof.txt
+++ b/Documentation/devicetree/bindings/spi/sh-msiof.txt
@@ -36,7 +36,21 @@ Required properties:
 
 Optional properties:
 - clocks               : Must contain a reference to the functional clock.
-- num-cs               : Total number of chip-selects (default is 1)
+- num-cs               : Total number of chip selects (default is 1).
+			 Up to 3 native chip selects are supported:
+			   0: MSIOF_SYNC
+			   1: MSIOF_SS1
+			   2: MSIOF_SS2
+			 Hardware limitations related to chip selects:
+			   - Native chip selects are always deasserted in
+			     between transfers that are part of the same
+			     message.  Use cs-gpios to work around this.
+			   - All slaves using native chip selects must use the
+			     same spi-cs-high configuration.  Use cs-gpios to
+			     work around this.
+			   - When using GPIO chip selects, at least one native
+			     chip select must be left unused, as it will be
+			     driven anyway.
 - dmas                 : Must contain a list of two references to DMA
 			 specifiers, one for transmission, and one for
 			 reception.