On Mon, Sep 24, 2018 at 02:04:24PM -0700, Rob Herring wrote:

On Fri, Sep 14, 2018 at 11:03:09PM +0300, Peter De Schrijver wrote:

quoted

Signed-off-by: Peter De Schrijver <redacted>

Needs a commit msg.

quoted

---
 .../memory-controllers/nvidia,tegra210-emc.txt     | 448 +++++++++++++++++++++
 1 file changed, 448 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/nvidia,tegra210-emc.txt

diff --git a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra210-emc.txt b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra210-emc.txt
new file mode 100644
index 0000000..1c52f47
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra210-emc.txt

@@ -0,0 +1,448 @@
+NVIDIA Tegra210 SoC EMC (external memory controller)
+====================================================
+
+Required properties :
+- compatible : Should be "nvidia,tegra21-emc", "nvidia,tegra124-emc".
+- reg : physical base address and length of the controller's registers.
+- nvidia,memory-controller : phandle of the MC driver.

Huh? What is this block then?

quoted

+- clocks : phandles of the possible source clocks
+- clock-names : names of the possible source clocks
+
+The node should contain a "emc-table" subnode for each supported RAM type
+(see field RAM_CODE in register PMC_STRAPPING_OPT_A), with its unit address
+being its RAM_CODE.

Unit address is based on reg property.

quoted

+
+Required properties for "emc-table" nodes :
+- nvidia,ram-code : Should contain the value of RAM_CODE this timing set is
+used for.
+
+Each "emc-table" node should contain a "emc-table" subnode for every supported
+EMC clock rate. The "emc-table" subnodes should have the clock rate in kHz as
+their unit address.
+
+Required properties for "emc-table" nodes :

Which emc-table nodes, the child or grand-child nodes?

quoted

+- compatible  "nvidia,tegra21-emc-table", "nvidia,tegra210-emc-table"

quoted

+- nvidia,revision : revision of the parameter set used for this node. All
+                    nodes in the same "emc-table" should have the same revision
+- clock-frequency : frequency in kHz
+- nvidia,emc-min-mv : minimum voltage for this OPP
+- nvidia,gk20a-min-mv : minimum GPU voltage for this OPP
+- nvidia,source : clock source to be used for this OPP

Is this memory timings/settings or OPPs? We have a binding for OPPs 
already.

quoted

+- nvidia,src-sel-reg : value of EMC CAR register to be used for this OPP
+- nvidia,needs-training : 1 if the OPP needs training at boot, 0 otherwise
+- nvidia,trained : 1 if initial training has been done by firmware, 0 otherwise
+- nvidia,periodic_training : 1 if the OPP needs periodic training, 0 otherwise
+- nvidia,trained_dram_clktree_c0d0u0 : training data word
+- nvidia,trained_dram_clktree_c0d0u1 : training data word

[...]

This is a huge list of properties. For all the things that are memory 
timings, is there really value to defining a property for each setting? 
Perhaps you should just define your own format and either make it a 
separate firmware file or include that file in the dtb.

The problem with moving to a binary blob is that it will break compatibility
with existing devices (eg. Jetson TX1 and shield TV) because their bootloaders
rely on the existing format.

Peter.