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Subject[PATCH V1 21/26] DT bindings: spi: add tx/rx clock delay SPI client properties
Date
This patch adds Tegra SPI master tx and rx clock delay properties.

TX/RX clock delays may vary depending on the platform design trace lengths
for each client on the Tegra SPI bus. These properties helps to tune the
clock delays.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
---
.../devicetree/bindings/spi/nvidia,tegra114-spi.txt | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/Documentation/devicetree/bindings/spi/nvidia,tegra114-spi.txt b/Documentation/devicetree/bindings/spi/nvidia,tegra114-spi.txt
index 6167c5234b64..2b84b7b726ce 100644
--- a/Documentation/devicetree/bindings/spi/nvidia,tegra114-spi.txt
+++ b/Documentation/devicetree/bindings/spi/nvidia,tegra114-spi.txt
@@ -29,6 +29,12 @@ spi-client device controller properties:
- nvidia,cs-hold-clk-count: CS hold timing parameter.
- nvidia,cs-inactive-cycles: CS inactive delay in terms of clock between
transfers.
+- nvidia,tx-clk-tap-delay: Delays the clock going out to the external device
+ with this tap value. This property is used to tune the outgoing data from
+ Tegra SPI master with respect to outgoing Tegra SPI master clock.
+- nvidia,rx-clk-tap-delay: Delays the clock coming in from the external device
+ with this tap value. This property is used to adjust the Tegra SPI master
+ clock with respect to the data from the SPI slave device.

Example:

@@ -45,4 +51,14 @@ spi@7000d600 {
reset-names = "spi";
dmas = <&apbdma 16>, <&apbdma 16>;
dma-names = "rx", "tx";
+
+ <spi-client>@<bus_num> {
+ ...
+ ...
+ nvidia,cs-setup-clk-count = <10>;
+ nvidia,cs-hold-clk-count = <10>;
+ nvidia,rx-clk-tap-delay = <0>;
+ nvidia,tx-clk-tap-delay = <16>;
+ ...
+ };
};
--
2.7.4
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