According to Data Manual(SPRS915P) of AM57x, TI QSPI controller on
DRA74(rev 1.1+)/DRA72 EVM can support up to 64MHz in MODE-0, whereas
MODE-3 is limited to 48MHz. Hence, switch to MODE-0 for better
throughput.
Signed-off-by: Vignesh R <vigneshr@xxxxxx>
---
v2: rebased on linux-next 20160419 to include moving to
dra72-evm-common.dtsi
Documentation/devicetree/bindings/spi/ti_qspi.txt | 7 +++++++
arch/arm/boot/dts/dra7-evm.dts | 6 ++----
arch/arm/boot/dts/dra72-evm-common.dtsi | 6 ++----
3 files changed, 11 insertions(+), 8 deletions(-)
diff --git a/Documentation/devicetree/bindings/spi/ti_qspi.txt b/Documentation/devicetree/bindings/spi/ti_qspi.txt
index cc8304aa64ac..50b14f6b53a3 100644
--- a/Documentation/devicetree/bindings/spi/ti_qspi.txt
+++ b/Documentation/devicetree/bindings/spi/ti_qspi.txt
@@ -19,6 +19,13 @@ Optional properties:
- syscon-chipselects: Handle to system control region contains QSPI
chipselect register and offset of that register.
+NOTE: TI QSPI controller requires different pinmux and IODelay
+paramaters for Mode-0 and Mode-3 operations, which needs to be set up by
+the bootloader (U-Boot). Default configuration only supports Mode-0
+operation. Hence, "spi-cpol" and "spi-cpha" DT properties cannot be
+specified in the slave nodes of TI QSPI controller without appropriate
+modification to bootloader.
+
Example:
For am4372:
diff --git a/arch/arm/boot/dts/dra7-evm.dts b/arch/arm/boot/dts/dra7-evm.dts
index 47d0745a08ad..507a8ec0a268 100644
--- a/arch/arm/boot/dts/dra7-evm.dts
+++ b/arch/arm/boot/dts/dra7-evm.dts
@@ -664,15 +664,13 @@
&qspi {
status = "okay";
- spi-max-frequency = <48000000>;
+ spi-max-frequency = <64000000>;
m25p80@0 {
compatible = "s25fl256s1";
- spi-max-frequency = <48000000>;
+ spi-max-frequency = <64000000>;
reg = <0>;
spi-tx-bus-width = <1>;
spi-rx-bus-width = <4>;
- spi-cpol;
- spi-cpha;
#address-cells = <1>;
#size-cells = <1>;
diff --git a/arch/arm/boot/dts/dra72-evm-common.dtsi b/arch/arm/boot/dts/dra72-evm-common.dtsi
index beef82502ea0..e53b1ef8c7aa 100644
--- a/arch/arm/boot/dts/dra72-evm-common.dtsi
+++ b/arch/arm/boot/dts/dra72-evm-common.dtsi
@@ -681,15 +681,13 @@
&qspi {
status = "okay";
- spi-max-frequency = <48000000>;
+ spi-max-frequency = <64000000>;
m25p80@0 {
compatible = "s25fl256s1";
- spi-max-frequency = <48000000>;
+ spi-max-frequency = <64000000>;
reg = <0>;
spi-tx-bus-width = <1>;
spi-rx-bus-width = <4>;
- spi-cpol;
- spi-cpha;
#address-cells = <1>;
#size-cells = <1>;
--
2.8.1
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