Hi Rob,

On 5/8/19 10:35 PM, Rob Herring wrote:

On Wed, May 8, 2019 at 4:45 AM Lukasz Luba [off-list ref] wrote:

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On 5/8/19 9:19 AM, Krzysztof Kozlowski wrote:

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On Tue, 7 May 2019 at 19:04, Rob Herring [off-list ref] wrote:

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+- devfreq-events : phandles of the PPMU events used by the controller.
+- samsung,syscon-chipid : phandle of the ChipID used by the controller.
+- samsung,syscon-clk : phandle of the clock register set used by the controller.

Looks like a hack. Can't you get this from the clocks property? What is
this for?

Hi Rob,

Lukasz uses these two syscon regmaps to read certain registers. For
chipid he reads it to check the size of attached memory (only 2 GB
version is supported). This indeed looks like a hack. However the
second regmap (clk) is needed to get the timing data from registers
from DMC clock driver address space. These are registers with memory
timing so their data is not exposed anyway in common clk framework.

Okay, please just explain what your accessing. Consider adding the
offset as a cell in case stuff moves around on another chip.

Good point. I will also have to regmap the registers and not take from
'clock' device.

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Best regards,
Krzysztof

Thank you Krzysztof for a fast response. I have also responded to Rob.
I wouldn't call accessing chipid registers as a hack, though. The DMC
registers do not contain information about the memory chip since it is
in phase of production the board not the chip. Thus, chipid regs (which
loads from e-fuses) are best place to put information about memory
type/size.

For efuses, we have a binding (nvmem). Maybe you should use it.

I don't know about the design of a planned 'chipid' driver, which going
to be sent to LKML in near future. Thank you for this information,
I will talk with Bartek.

Regards,
Lukasz

Rob