The patch
spi: Improve DT binding documentation
has been applied to the spi tree at
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git
All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying
to this mail.
Thanks,
Mark
>From a777059a3fc13f51e91442ccf043c8e3bcd1c48f Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Date: Wed, 22 Jun 2016 14:48:26 +0200
Subject: [PATCH] spi: Improve DT binding documentation
- Add missing verbs and periods,
- Add spaces before opening parentheses,
- Align list layout,
- Correct grammar,
- Move "cs-gpios" from the required to the optional properties
section,
- Remove spaces before tabs.
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
Documentation/devicetree/bindings/spi/spi-bus.txt | 35 ++++++++++++-----------
1 file changed, 18 insertions(+), 17 deletions(-)
diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt
index 42d595425dfb..17822860cb98 100644
--- a/Documentation/devicetree/bindings/spi/spi-bus.txt
+++ b/Documentation/devicetree/bindings/spi/spi-bus.txt
@@ -8,11 +8,10 @@ in slave mode.
The SPI master node requires the following properties:
- #address-cells - number of cells required to define a chip select
- address on the SPI bus.
+ address on the SPI bus.
- #size-cells - should be zero.
- compatible - name of SPI bus controller following generic names
- recommended practice.
-- cs-gpios - (optional) gpios chip select.
+ recommended practice.
No other properties are required in the SPI bus node. It is assumed
that a driver for an SPI bus device will understand that it is an SPI bus.
However, the binding does not attempt to define the specific method for
@@ -22,11 +21,12 @@ assumption that board specific platform code will be used to manage
chip selects. Individual drivers can define additional properties to
support describing the chip select layout.
-Optional property:
-- num-cs : total number of chipselects
+Optional properties:
+- cs-gpios - gpios chip select.
+- num-cs - total number of chipselects.
-If cs-gpios is used the number of chip select will automatically increased
-with max(cs-gpios > hw cs)
+If cs-gpios is used the number of chip selects will be increased automatically
+with max(cs-gpios > hw cs).
So if for example the controller has 2 CS lines, and the cs-gpios
property looks like this:
@@ -45,29 +45,30 @@ SPI slave nodes must be children of the SPI master node and can
contain the following properties.
- reg - (required) chip select address of device.
- compatible - (required) name of SPI device following generic names
- recommended practice
-- spi-max-frequency - (required) Maximum SPI clocking speed of device in Hz
+ recommended practice.
+- spi-max-frequency - (required) Maximum SPI clocking speed of device in Hz.
- spi-cpol - (optional) Empty property indicating device requires
- inverse clock polarity (CPOL) mode
+ inverse clock polarity (CPOL) mode.
- spi-cpha - (optional) Empty property indicating device requires
- shifted clock phase (CPHA) mode
+ shifted clock phase (CPHA) mode.
- spi-cs-high - (optional) Empty property indicating device requires
- chip select active high
+ chip select active high.
- spi-3wire - (optional) Empty property indicating device requires
- 3-wire mode.
+ 3-wire mode.
- spi-lsb-first - (optional) Empty property indicating device requires
LSB first mode.
-- spi-tx-bus-width - (optional) The bus width(number of data wires) that
+- spi-tx-bus-width - (optional) The bus width (number of data wires) that is
used for MOSI. Defaults to 1 if not present.
-- spi-rx-bus-width - (optional) The bus width(number of data wires) that
+- spi-rx-bus-width - (optional) The bus width (number of data wires) that is
used for MISO. Defaults to 1 if not present.
- spi-rx-delay-us - (optional) Microsecond delay after a read transfer.
- spi-tx-delay-us - (optional) Microsecond delay after a write transfer.
Some SPI controllers and devices support Dual and Quad SPI transfer mode.
-It allows data in the SPI system to be transferred in 2 wires(DUAL) or 4 wires(QUAD).
+It allows data in the SPI system to be transferred using 2 wires (DUAL) or 4
+wires (QUAD).
Now the value that spi-tx-bus-width and spi-rx-bus-width can receive is
-only 1(SINGLE), 2(DUAL) and 4(QUAD).
+only 1 (SINGLE), 2 (DUAL) and 4 (QUAD).
Dual/Quad mode is not allowed when 3-wire mode is used.
If a gpio chipselect is used for the SPI slave the gpio number will be passed
--
2.8.1
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