On 09/30/2014 07:04 PM, Marc Kleine-Budde wrote:

On 09/30/2014 05:25 PM, Wolfram Sang wrote:

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Yes, but syscon_regmap_lookup_by_phandle() doesn't need any support for
additional parameters. Have a look at:

drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c

First get the regmap, then the 1st argument is the offset in the regmap,
the 2nd and 3rd could be the bits.

So, for one driver the extra arguments are: <reg> <start_bit> <stop_bit>
For another driver (the stmmac example): <reg_offset> <reg_shift>

The DCAN's "reg" is a "reg_offset" as in the stmmc.

Roger, can we derive both start and done bit from a common reg_shift?

I'm sorry I didn't understand what you meant.

<&syscon_phandl> <reg offset> <start bit> <stop bit> should work well for us.
Even though reg offset is the same for both the DCAN instances.

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Phew... Then we should really have a "syscon-raminit" property probably,
so that at least plain "syscon" has a consistent syntax?

I think^whope we can have the same syntax as the stmmc :D

I agree too.

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So, I'd rather drop additional arguments.

Why would you like to have it encoded in DT?

Where put the information then? Into the driver, but where do you get
the reference which instance of the DCAN you are, so that you can look
up the correct bits?

Agreed. I thought we had this information in the driver already, but we
haven't...

The current driver relies on the of_alias_get_id(), which isn't
considered best practice, is it? So I want to avoid this when switching
to syscon.

cheers,
-roger