[PATCH v5 05/14] of: Document timings subnode of nvidia,tegra-mc

Tomeu Vizoso
2014-11-18T12:23:11Z

The MC driver needs some timing-specific information to program the EMEM during
a rate change of the EMC clock.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>

---

v4: * Add more information about nvidia,emem-configuration
* Remove mandatory naming of the timings subnode
* Remove constraint on the unit-address of the timings and timing subnodes
---
.../memory-controllers/nvidia,tegra-mc.txt | 84 +++++++++++++++++++++-
1 file changed, 82 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra-mc.txt b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra-mc.txt
index f3db93c..3338a28 100644
--- a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra-mc.txt
+++ b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra-mc.txt
@@ -1,6 +1,9 @@
NVIDIA Tegra Memory Controller device tree bindings
===================================================

+memory-controller node
+----------------------
+
Required properties:
- compatible: Should be "nvidia,tegra<chip>-mc"
- reg: Physical base address and length of the controller's registers.
@@ -15,9 +18,49 @@ Required properties:
This device implements an IOMMU that complies with the generic IOMMU binding.
See ../iommu/iommu.txt for details.

-Example:
---------
+emc-timings subnode
+-------------------
+
+The node should contain a "emc-timings" subnode for each supported RAM type (see field RAM_CODE in
+register PMC_STRAPPING_OPT_A).
+
+Required properties for "emc-timings" nodes :
+- nvidia,ram-code : Should contain the value of RAM_CODE this timing set is used for.
+
+timing subnode
+--------------
+
+Each "emc-timings" node should contain a subnode for every supported EMC clock rate.
+
+Required properties for timing nodes :
+- clock-frequency : Should contain the memory clock rate in Hz.
+- nvidia,emem-configuration : Values to be written to the EMEM register block. For the Tegra124 SoC
+(see section "15.6.1 MC Registers" in the TRM), these are the registers whose values need to be
+specified, according to the board documentation:
+
+ MC_EMEM_ARB_CFG
+ MC_EMEM_ARB_OUTSTANDING_REQ
+ MC_EMEM_ARB_TIMING_RCD
+ MC_EMEM_ARB_TIMING_RP
+ MC_EMEM_ARB_TIMING_RC
+ MC_EMEM_ARB_TIMING_RAS
+ MC_EMEM_ARB_TIMING_FAW
+ MC_EMEM_ARB_TIMING_RRD
+ MC_EMEM_ARB_TIMING_RAP2PRE
+ MC_EMEM_ARB_TIMING_WAP2PRE
+ MC_EMEM_ARB_TIMING_R2R
+ MC_EMEM_ARB_TIMING_W2W
+ MC_EMEM_ARB_TIMING_R2W
+ MC_EMEM_ARB_TIMING_W2R
+ MC_EMEM_ARB_DA_TURNS
+ MC_EMEM_ARB_DA_COVERS
+ MC_EMEM_ARB_MISC0
+ MC_EMEM_ARB_MISC1
+ MC_EMEM_ARB_RING1_THROTTLE

+Example SoC include file:
+
+/ {
mc: memory-controller@0,70019000 {
compatible = "nvidia,tegra124-mc";
reg = <0x0 0x70019000 0x0 0x1000>;
@@ -34,3 +77,40 @@ Example:
...
iommus = <&mc TEGRA_SWGROUP_SDMMC1A>;
};
+};
+
+Example board file:
+
+/ {
+ memory-controller@0,70019000 {
+ emc-timings-3 {
+ nvidia,ram-code = <3>;
+
+ timing-12750000 {
+ clock-frequency = <12750000>;
+
+ nvidia,emem-configuration = <
+ 0x40040001 /* MC_EMEM_ARB_CFG */
+ 0x8000000a /* MC_EMEM_ARB_OUTSTANDING_REQ */
+ 0x00000001 /* MC_EMEM_ARB_TIMING_RCD */
+ 0x00000001 /* MC_EMEM_ARB_TIMING_RP */
+ 0x00000002 /* MC_EMEM_ARB_TIMING_RC */
+ 0x00000000 /* MC_EMEM_ARB_TIMING_RAS */
+ 0x00000002 /* MC_EMEM_ARB_TIMING_FAW */
+ 0x00000001 /* MC_EMEM_ARB_TIMING_RRD */
+ 0x00000002 /* MC_EMEM_ARB_TIMING_RAP2PRE */
+ 0x00000008 /* MC_EMEM_ARB_TIMING_WAP2PRE */
+ 0x00000003 /* MC_EMEM_ARB_TIMING_R2R */
+ 0x00000002 /* MC_EMEM_ARB_TIMING_W2W */
+ 0x00000003 /* MC_EMEM_ARB_TIMING_R2W */
+ 0x00000006 /* MC_EMEM_ARB_TIMING_W2R */
+ 0x06030203 /* MC_EMEM_ARB_DA_TURNS */
+ 0x000a0402 /* MC_EMEM_ARB_DA_COVERS */
+ 0x77e30303 /* MC_EMEM_ARB_MISC0 */
+ 0x70000f03 /* MC_EMEM_ARB_MISC1 */
+ 0x001f0000 /* MC_EMEM_ARB_RING1_THROTTLE */
+ >;
+ };
+ };
+ };
+};
--
1.9.3