First cut at device tree bindings for the EMC tables on tegra.
Note that I have a prerequisite patch that changes the tegra2_emc code
to be a platform driver; but I wanted to do a sanity-check of my device
tree usage here before posting the whole series.
Signed-off-by: Olof Johansson <olof@xxxxxxxxx>
---
.../devicetree/bindings/arm/tegra/emc.txt | 77 ++++++++++++++++++++
arch/arm/boot/dts/tegra-seaboard.dts | 36 +++++++++
arch/arm/boot/dts/tegra20.dtsi | 7 ++
3 files changed, 120 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/arm/tegra/emc.txt
diff --git a/Documentation/devicetree/bindings/arm/tegra/emc.txt b/Documentation/devicetree/bindings/arm/tegra/emc.txt
new file mode 100644
index 0000000..dd7f845
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/tegra/emc.txt
@@ -0,0 +1,77 @@
+Embedded Memory Controller
+
+Properties:
+- name : Should be emc
+- #address-cells : Should be 1
+- #size-cells : Should be 0
+- compatible : should contain "nvidia,tegra20-emc".
+- reg : Offset and length of the register set for the device
+- nvidia,use-ram-code : If present, the sub-nodes will be addressed
+ and chosen using the ramcode board selector. If omitted, only one
+ set of tables can be present and said tables will be used
+ irrespective of ram-code configuration.
+
+Child device nodes describe the memory settings for different configurations and clock rates.
+
+Example:
+
+ emc@7000f400 {
+ #address-cells = < 1 >;
+ #size-cells = < 0 >;
+ compatible = "nvidia,tegra20-emc";
+ reg = <0x7000f4000 0x200>;
+ }
+
+
+Embedded Memory Controller configuration table
+
+This is a table containing the EMC register settings for the various
+operating speeds of the memory controller. They are always located as
+subnodes of the emc controller node.
+
+There are two ways of specifying which tables to use:
+
+* The simplest is if there is just one set of tables in the device tree,
+ and they will always be used (based on which frequency is used).
+ This is the preferred method, especially when firmware can fill in
+ this information based on the specific system information and just
+ pass it on to the kernel.
+
+* The slightly more complex one is when more than one memory configuration
+ might exist on the system. The Tegra20 platform handles this during
+ early boot by selecting one out of possible 4 memory settings based
+ on a 2-pin "ram code" bootstrap setting on the board. The values of
+ these strappings can be read through a register in the SoC, and thus
+ used to select which tables to use.
+
+Properties:
+- name : Should start with emc-table
+- compatible : should contain "nvidia,tegra20-emc-table".
+- reg : only needed if nvidia,use-ram-code is present in the
+ parent. If so, the numerical representation of the selected ram code
+ as reported by the strap option APB misc register.
+- clock-frequency : the clock frequency for the EMC at which this
+ table should be used (in kHz).
+- nvidia,emc-registers : a 46 word array of EMC registers to be programmed
+ for operation at the 'clock-frequency' setting.
+ The order and contents of the registers are defined in the Tegra TRM.
+
+ emc-table-333mhz@0 {
+ reg = <0>;
+ compatible = "nvidia,tegra20-emc-table";
+ clock-frequency = < 333000 >;
+ nvidia,emc-registers = < 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+ 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+ 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+ 0 0 0 0 >;
+ };
+
+ emc-table-666mhz@0 {
+ reg = <0>;
+ compatible = "nvidia,tegra20-emc-table";
+ clock-frequency = < 666000 >;
+ nvidia,emc-registers = < 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+ 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+ 0 0 0 0 0 0 0 0 0 0 0 0 0 0
+ 0 0 0 0 >;
+ };
diff --git a/arch/arm/boot/dts/tegra-seaboard.dts b/arch/arm/boot/dts/tegra-seaboard.dts
index a72299b..2d60b5ff 100644
--- a/arch/arm/boot/dts/tegra-seaboard.dts
+++ b/arch/arm/boot/dts/tegra-seaboard.dts
@@ -20,6 +20,42 @@
clock-frequency = < 216000000 >;
};
+ emc {
+ emc-table-166 {
+ compatible = "nvidia,tegra20-emc-table";
+ clock-frequency = < 166500 >;
+ nvidia,emc-registers = < 0x0000000a 0x00000021
+ 0x00000008 0x00000003 0x00000004 0x00000004
+ 0x00000002 0x0000000c 0x00000003 0x00000003
+ 0x00000002 0x00000001 0x00000004 0x00000005
+ 0x00000004 0x00000009 0x0000000d 0x000004df
+ 0x00000000 0x00000003 0x00000003 0x00000003
+ 0x00000003 0x00000001 0x0000000a 0x000000c8
+ 0x00000003 0x00000006 0x00000004 0x0000000f
+ 0x00000002 0x00000000 0x00000000 0x00000002
+ 0x00000000 0x00000000 0x00000083 0xa04004ae
+ 0x007fd010 0x00000000 0x00000000 0x00000000
+ 0x00000000 0x00000000 0x00000000 0x00000000 >;
+ };
+
+ emc-table-333 {
+ compatible = "nvidia,tegra20-emc-table";
+ clock-frequency = < 333000 >;
+ nvidia,emc-registers = < 0x00000014 0x00000041
+ 0x0000000f 0x00000005 0x00000004 0x00000005
+ 0x00000003 0x0000000c 0x00000005 0x00000005
+ 0x00000003 0x00000001 0x00000004 0x00000005
+ 0x00000004 0x00000009 0x0000000d 0x000009ff
+ 0x00000000 0x00000003 0x00000003 0x00000005
+ 0x00000005 0x00000001 0x0000000f 0x000000c8
+ 0x00000003 0x0000000c 0x00000006 0x0000000f
+ 0x00000002 0x00000000 0x00000000 0x00000002
+ 0x00000000 0x00000000 0x00000083 0xe034048b
+ 0x007e8010 0x00000000 0x00000000 0x00000000
+ 0x00000000 0x00000000 0x00000000 0x00000000 >;
+ };
+ };
+
sdhci@c8000400 {
cd-gpios = <&gpio 69 0>; /* gpio PI5 */
wp-gpios = <&gpio 57 0>; /* gpio PH1 */
diff --git a/arch/arm/boot/dts/tegra20.dtsi b/arch/arm/boot/dts/tegra20.dtsi
index 65d7e6a..f4dc8d3 100644
--- a/arch/arm/boot/dts/tegra20.dtsi
+++ b/arch/arm/boot/dts/tegra20.dtsi
@@ -120,6 +120,13 @@
interrupts = < 123 >;
};
+ emc@7000f400 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ compatible = "nvidia,tegra20-emc";
+ reg = <0x7000f400 0x200>;
+ };
+
sdhci@c8000000 {
compatible = "nvidia,tegra20-sdhci";
reg = <0xc8000000 0x200>;
--
1.7.4.1
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