path: root/Documentation
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authorAndy Gross <agross@codeaurora.org>2014-06-12 14:34:10 -0500
committerMark Brown <broonie@linaro.org>2014-06-22 11:48:09 +0100
commit4a8573abe965115bc5b064401fd669b74e985258 (patch)
tree933fae200342e47c9bf596b31847e9477e093e38 /Documentation
parent045c243a511c8b688d36659cc3f781e84e9c2ddb (diff)
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')
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
+- 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

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