Re: [RFC 14/14] dt-bindings: tegra: Add Tegra210 EMC binding
From: Rob Herring <robh@kernel.org>
Date: 2018-09-24 21:04:24
On Fri, Sep 14, 2018 at 11:03:09PM +0300, Peter De Schrijver wrote:
Signed-off-by: Peter De Schrijver <redacted>
Needs a commit msg.
quoted hunk ↗ jump to hunk
--- .../memory-controllers/nvidia,tegra210-emc.txt | 448 +++++++++++++++++++++ 1 file changed, 448 insertions(+) create mode 100644 Documentation/devicetree/bindings/memory-controllers/nvidia,tegra210-emc.txtdiff --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?
+- 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.
+ +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?
+- compatible "nvidia,tegra21-emc-table", "nvidia,tegra210-emc-table"
+- 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.
+- 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. Rob