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 <[email protected]> --- .../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 -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
