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| author | Trent Piepho <tpiepho@impinj.com> | 2017-11-15 11:52:32 -0800 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2017-11-16 11:04:44 +0000 |
| commit | 8c059a4676038967dd6efe614538c329b61e68a1 (patch) | |
| tree | 7c7bed3644d24a08e1cea7378f62d034882d6a25 /Documentation | |
| parent | abbdb5ce31c21a4b3c3922c56030f3d487497933 (diff) | |
| download | linux-8c059a4676038967dd6efe614538c329b61e68a1.tar.gz linux-8c059a4676038967dd6efe614538c329b61e68a1.tar.bz2 linux-8c059a4676038967dd6efe614538c329b61e68a1.zip | |
spi: imx: Update device tree binding documentation
Update documentation for gpio-cs and num-cs to reflect the standard SPI
bindings.
The dma properties are optional.
Include a warning that native CS do not work in a commonly useful manner
with this hardware/driver, and therefor most users probably should use GPIO
based CS lines rather than native.
CC: Mark Brown <broonie@kernel.org>
CC: Shawn Guo <shawnguo@kernel.org>
CC: Sascha Hauer <kernel@pengutronix.de>
CC: Fabio Estevam <fabio.estevam@nxp.com>
CC: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt index 5bf13960f7f4..e3c48b20b1a6 100644 --- a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt +++ b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt @@ -12,24 +12,30 @@ Required properties: - "fsl,imx53-ecspi" for SPI compatible with the one integrated on i.MX53 and later Soc - reg : Offset and length of the register set for the device - interrupts : Should contain CSPI/eCSPI interrupt -- cs-gpios : Specifies the gpio pins to be used for chipselects. - clocks : Clock specifiers for both ipg and per clocks. - clock-names : Clock names should include both "ipg" and "per" See the clock consumer binding, Documentation/devicetree/bindings/clock/clock-bindings.txt -- dmas: DMA specifiers for tx and rx dma. See the DMA client binding, - Documentation/devicetree/bindings/dma/dma.txt -- dma-names: DMA request names should include "tx" and "rx" if present. -Obsolete properties: -- fsl,spi-num-chipselects : Contains the number of the chipselect +Recommended properties: +- cs-gpios : GPIOs to use as chip selects, see spi-bus.txt. While the native chip +select lines can be used, they appear to always generate a pulse between each +word of a transfer. Most use cases will require GPIO based chip selects to +generate a valid transaction. Optional properties: +- num-cs : Number of total chip selects, see spi-bus.txt. +- dmas: DMA specifiers for tx and rx dma. See the DMA client binding, +Documentation/devicetree/bindings/dma/dma.txt. +- dma-names: DMA request names, if present, should include "tx" and "rx". - fsl,spi-rdy-drctl: Integer, representing the value of DRCTL, the register controlling the SPI_READY handling. Note that to enable the DRCTL consideration, the SPI_READY mode-flag needs to be set too. Valid values are: 0 (disabled), 1 (edge-triggered burst) and 2 (level-triggered burst). +Obsolete properties: +- fsl,spi-num-chipselects : Contains the number of the chipselect + Example: ecspi@70010000 { |