On Wed, Jan 17, 2018 at 11:31 AM, PrasannaKumar Muralidharan
[off-list ref] wrote:

Hi Rob,

On 11 January 2018 at 20:38, Rob Herring [off-list ref] wrote:

quoted

On Sat, Jan 6, 2018 at 6:43 AM, PrasannaKumar Muralidharan
[off-list ref] wrote:

quoted

Hi Rob,

On 4 January 2018 at 01:32, Rob Herring [off-list ref] wrote:

quoted

On Thu, Dec 28, 2017 at 10:29:52PM +0100, Mathieu Malaterre wrote:

quoted

From: PrasannaKumar Muralidharan <redacted>

[...]

quoted

quoted

quoted

quoted

+             nemc: nemc@13410000 {
+                     compatible = "ingenic,jz4780-nemc";
+                     reg = <0x13410000 0x10000>;
+                     #address-cells = <2>;
+                     #size-cells = <1>;
+                     ranges = <1 0 0x1b000000 0x1000000
+                               2 0 0x1a000000 0x1000000
+                               3 0 0x19000000 0x1000000
+                               4 0 0x18000000 0x1000000
+                               5 0 0x17000000 0x1000000
+                               6 0 0x16000000 0x1000000>;
+
+                     clocks = <&cgu JZ4780_CLK_NEMC>;
+
+                     status = "disabled";
+             };

-             clocks = <&cgu JZ4780_CLK_NEMC>;
+             efuse: efuse@134100d0 {
+                     compatible = "ingenic,jz4780-efuse";
+                     reg = <0x134100d0 0xff>;

You are creating an overlapping region here with nemc above. Don't do
that.

Should "reg = <0x13410000 0x10000>;" be used instead?

No, that still overlaps with nemc. What's in registers 0x00-0xcf and
0x1d0-0xffff? Either get rid of this node altogether and make the
driver for nemc also instantiate the efuse driver (DT is not the only
way to instantiate drivers), or create sub-nodes under nemc for each
distinct h/w block in the 13410000-13420000 address space.

My idea was not to change nemc driver.

By "create sub-nodes under nemc" do you mean something like below?

Yes.

nemc: nemc@13410000 {
                     compatible = "ingenic,jz4780-nemc";
                     reg = <0x13410000 0x10000>;
                     <...>
                     status = "disabled";

Though having disabled here is strange. We'd normally ignore all the
child nodes.

                     efuse: efuse@134101d0 {
                                          compatible = "ingenic,jz4780-efuse";
                                          reg = <0x134100d0 0xff>;
                     }
}

Will this instantiate efuse driver? I do not know how to do that with
sub-node. I will explore more on this.

The nemc driver just needs to call of_platform_default_populate.

quoted

Or a third option is make nemc reg:

reg = <0x13410000 0xd0>, <0x134101d0 0xfe30>;

But I suspect that is wrong and you probably have some other function in there.

Rob

If the efuse block were to use a different base register address (that
does not overlap with nemc register range) in future SoC how the node
should be? Using nemc to instantiate efuse won't be the best choice if
that happens.

Then you will have a different compatible for nemc (because it is
different) and then the driver should skip the above step.

Rob
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