diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/spi/sh-msiof.txt | 16 |
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. |