ARM: dts: dra7x: Support QSPI MODE-0 operation at 64MHz

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@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/Documentation/devicetree/bindings/spi/ti_qspi.txt b/Documentation/devicetree/bindings/spi/ti_qspi.txt
index cc8304a..50b14f6 100644 (file)
--- 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 98bc5ca..bafcfac 100644 (file)
--- 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 2894759..093538e 100644 (file)
--- 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>;