diff options
| author | Andy Gross <agross@codeaurora.org> | 2014-06-12 14:34:10 -0500 |
|---|---|---|
| committer | Mark Brown <broonie@linaro.org> | 2014-06-22 11:48:09 +0100 |
| commit | 4a8573abe965115bc5b064401fd669b74e985258 (patch) | |
| tree | 933fae200342e47c9bf596b31847e9477e093e38 /Documentation | |
| parent | 045c243a511c8b688d36659cc3f781e84e9c2ddb (diff) | |
| download | linux-4a8573abe965115bc5b064401fd669b74e985258.tar.bz2 | |
spi: qup: Remove chip select function
This patch removes the chip select function. Chip select should instead be
supported using GPIOs, defining the DT entry "cs-gpios", and letting the SPI
core assert/deassert the chip select as it sees fit.
The chip select control inside the controller is buggy. It is supposed to
automatically assert the chip select based on the activity in the controller,
but it is buggy and doesn't work at all. So instead we elect to use GPIOs.
Signed-off-by: Andy Gross <agross@codeaurora.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/spi/qcom,spi-qup.txt | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt b/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt index b82a268f1bd4..bee6ff204baf 100644 --- a/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt +++ b/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt @@ -23,6 +23,12 @@ Optional properties: - spi-max-frequency: Specifies maximum SPI clock frequency, Units - Hz. Definition as per Documentation/devicetree/bindings/spi/spi-bus.txt +- num-cs: total number of chipselects +- cs-gpios: should specify GPIOs used for chipselects. + The gpios will be referred to as reg = <index> in the SPI child + nodes. If unspecified, a single SPI device without a chip + select can be used. + SPI slave nodes must be children of the SPI master node and can contain properties described in Documentation/devicetree/bindings/spi/spi-bus.txt |