* [PATCH 1/2] ARM: dts: dra7x: Remove QSPI pinmux
2016-04-14 10:18 [PATCH 0/2] DRA7x: Increase QSPI frequency to 64MHz Vignesh R
@ 2016-04-14 10:18 ` Vignesh R
2016-04-14 10:18 ` [PATCH 2/2] ARM: dts: dra7x: Support QSPI MODE-0 operation at 64MHz Vignesh R
1 sibling, 0 replies; 5+ messages in thread
From: Vignesh R @ 2016-04-14 10:18 UTC (permalink / raw)
To: Tony Lindgren
Cc: Rob Herring, Vignesh R, nsekhar, devicetree, linux-kernel,
linux-omap, linux-arm-kernel
DRA7 family of processors from Texas Instruments, have a hardware module
called IODELAYCONFIG Module which is expected to be configured. This
block allows very specific custom fine tuning for electrical
characteristics of IO pins that are necessary for functionality and
device lifetime requirements. IODelay module has it's own register space
with registers to configure various pins.
According to AM572x TRM SPRUHZ6E October 2014–Revised January 2016[1]
section 18.4.6.1 Pad Configuration, in addition to pinmuxing(MUXMODE),
when operating a pad in certain mode, Virtual/Manual IO Timing Mode must
also be configured to ensure that IO timings are met (DELAYMODE and
MODESELECT fields of pad's IODELAYCONFIG module register). According to
section 18.4.6.1.7 Isolation Requirements of above TRM, when
reprogramming MUXMODE, DELAYMODE, and MODESELECT fields, there is a
potential for a significant glitch on the corresponding IO. It is hence
recommended to do this with I/O isolation (which can only be done in
initial stages of bootloader). QSPI is one such module that requires
IODELAY configuration. So, this patch removes the pinmux for
QSPI for DRA74/DRA72 EVM as it needs to be done in bootloader (U-Boot)
and cannot be done in kernel.
Users should migrate to U-Boot v2016.05-rc1 or higher.
[1] http://www.ti.com/lit/ug/spruhz6e/spruhz6e.pdf
Signed-off-by: Vignesh R <vigneshr@ti.com>
---
arch/arm/boot/dts/dra7-evm.dts | 17 -----------------
arch/arm/boot/dts/dra72-evm.dts | 14 --------------
2 files changed, 31 deletions(-)
diff --git a/arch/arm/boot/dts/dra7-evm.dts b/arch/arm/boot/dts/dra7-evm.dts
index d272cf140197..47d0745a08ad 100644
--- a/arch/arm/boot/dts/dra7-evm.dts
+++ b/arch/arm/boot/dts/dra7-evm.dts
@@ -226,21 +226,6 @@
>;
};
- qspi1_pins: pinmux_qspi1_pins {
- pinctrl-single,pins = <
- DRA7XX_CORE_IOPAD(0x344c, PIN_INPUT | MUX_MODE1) /* gpmc_a3.qspi1_cs2 */
- DRA7XX_CORE_IOPAD(0x3450, PIN_INPUT | MUX_MODE1) /* gpmc_a4.qspi1_cs3 */
- DRA7XX_CORE_IOPAD(0x3474, PIN_INPUT | MUX_MODE1) /* gpmc_a13.qspi1_rtclk */
- DRA7XX_CORE_IOPAD(0x3478, PIN_INPUT | MUX_MODE1) /* gpmc_a14.qspi1_d3 */
- DRA7XX_CORE_IOPAD(0x347c, PIN_INPUT | MUX_MODE1) /* gpmc_a15.qspi1_d2 */
- DRA7XX_CORE_IOPAD(0x3480, PIN_INPUT | MUX_MODE1) /* gpmc_a16.qspi1_d1 */
- DRA7XX_CORE_IOPAD(0x3484, PIN_INPUT | MUX_MODE1) /* gpmc_a17.qspi1_d0 */
- DRA7XX_CORE_IOPAD(0x3488, PIN_INPUT | MUX_MODE1) /* qpmc_a18.qspi1_sclk */
- DRA7XX_CORE_IOPAD(0x34b8, PIN_INPUT_PULLUP | MUX_MODE1) /* gpmc_cs2.qspi1_cs0 */
- DRA7XX_CORE_IOPAD(0x34bc, PIN_INPUT_PULLUP | MUX_MODE1) /* gpmc_cs3.qspi1_cs1 */
- >;
- };
-
usb1_pins: pinmux_usb1_pins {
pinctrl-single,pins = <
DRA7XX_CORE_IOPAD(0x3680, PIN_INPUT_SLEW | MUX_MODE0) /* usb1_drvvbus */
@@ -678,8 +663,6 @@
&qspi {
status = "okay";
- pinctrl-names = "default";
- pinctrl-0 = <&qspi1_pins>;
spi-max-frequency = <48000000>;
m25p80@0 {
diff --git a/arch/arm/boot/dts/dra72-evm.dts b/arch/arm/boot/dts/dra72-evm.dts
index 3e63f660cd7c..479b74e1641e 100644
--- a/arch/arm/boot/dts/dra72-evm.dts
+++ b/arch/arm/boot/dts/dra72-evm.dts
@@ -247,18 +247,6 @@
>;
};
- qspi1_pins: pinmux_qspi1_pins {
- pinctrl-single,pins = <
- DRA7XX_CORE_IOPAD(0x3474, PIN_OUTPUT | MUX_MODE1) /* gpmc_a13.qspi1_rtclk */
- DRA7XX_CORE_IOPAD(0x3478, PIN_INPUT | MUX_MODE1) /* gpmc_a14.qspi1_d3 */
- DRA7XX_CORE_IOPAD(0x347c, PIN_INPUT | MUX_MODE1) /* gpmc_a15.qspi1_d2 */
- DRA7XX_CORE_IOPAD(0x3480, PIN_INPUT | MUX_MODE1) /* gpmc_a16.qspi1_d1 */
- DRA7XX_CORE_IOPAD(0x3484, PIN_INPUT | MUX_MODE1) /* gpmc_a17.qspi1_d0 */
- DRA7XX_CORE_IOPAD(0x3488, PIN_OUTPUT | MUX_MODE1) /* qpmc_a18.qspi1_sclk */
- DRA7XX_CORE_IOPAD(0x34b8, PIN_OUTPUT | MUX_MODE1) /* gpmc_cs2.qspi1_cs0 */
- >;
- };
-
hdmi_pins: pinmux_hdmi_pins {
pinctrl-single,pins = <
DRA7XX_CORE_IOPAD(0x3808, PIN_INPUT | MUX_MODE1) /* i2c2_sda.hdmi1_ddc_scl */
@@ -715,8 +703,6 @@
&qspi {
status = "okay";
- pinctrl-names = "default";
- pinctrl-0 = <&qspi1_pins>;
spi-max-frequency = <48000000>;
m25p80@0 {
--
2.8.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/2] ARM: dts: dra7x: Support QSPI MODE-0 operation at 64MHz
2016-04-14 10:18 [PATCH 0/2] DRA7x: Increase QSPI frequency to 64MHz Vignesh R
2016-04-14 10:18 ` [PATCH 1/2] ARM: dts: dra7x: Remove QSPI pinmux Vignesh R
@ 2016-04-14 10:18 ` Vignesh R
2016-04-14 17:12 ` Rob Herring
1 sibling, 1 reply; 5+ messages in thread
From: Vignesh R @ 2016-04-14 10:18 UTC (permalink / raw)
To: Tony Lindgren
Cc: Rob Herring, Vignesh R, nsekhar, devicetree, linux-kernel,
linux-omap, linux-arm-kernel
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>
---
Documentation/devicetree/bindings/spi/ti_qspi.txt | 7 +++++++
arch/arm/boot/dts/dra7-evm.dts | 6 ++----
arch/arm/boot/dts/dra72-evm.dts | 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.dts b/arch/arm/boot/dts/dra72-evm.dts
index 479b74e1641e..46e1b72866f5 100644
--- a/arch/arm/boot/dts/dra72-evm.dts
+++ b/arch/arm/boot/dts/dra72-evm.dts
@@ -704,15 +704,13 @@
&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
^ permalink raw reply related [flat|nested] 5+ messages in thread