Re: AM335x ICE board Linux support

[Roger Quadros <rogerq-l0cyMroinI0@public.gmane.org>]

+Rob

On 25/04/16 14:59, Roger Quadros wrote:
> Hi,
> 
> We are working on getting Linux on AM335X Industrial Communication Engine board (ICE) [1].
> 
> This board has 2 Ethernet ports and each of them can be used either in RMII mode connected to
> the CPSW Ethernet MAC *or* in MII mode connected to the PRU Ethernet MAC.
> 
> The decision about the Ethernet port's mode is made by the user by setting a jumper near the
> Ethernet port before power up. This is a boot time configurable setting and doesn't need to
> change at runtime.
> 
> So 4 configurations are possible:
>     ETH0	ETH1
>     ----	----
>     RMII	RMII
>     RMII	MII
>     MII		RMII	(probably redundant and not needed)
>     MII		MII
> 
> Based on the port configuration, software (u-boot or Linux) needs to set the right pinmux,
> set a GPIOs (that controls external Mux), configure an external clock generator
> and enable the right device driver for the respective Ethernet port.
> 
> Clock generator needs to be configured because different clock rates are required
> for RMII vs MII mode.
> 
> Now question is how all this can be done on u-boot + Linux?
> 
> I already have a working solution where I create different DT blobs for the 3 configurations
> and have u-boot detect the mode and load the correct DT blob and also configure the clock.
> 
> You can see how the kernel patches look like here [2]
> 
> Is this approach acceptable? If not is there any better way to do this? Thanks.
> 
> cheers,
> -roger
> 
> [1] AM3359 ICE board
> http://www.ti.com/tool/tmdsice3359
> http://processors.wiki.ti.com/index.php/AM335x_Industrial_Communication_Engine_%28ICE%29_EVM_HW_User_Guide

There are 2 ICE board version. v1 and v2. The above wiki link is wrong.
We are dealing with the v2 board below
http://processors.wiki.ti.com/index.php/AM335x_Industrial_Communication_Engine_EVM_Rev2_1_HW_User_Guide
> 
> [2] Device tree patches
> https://github.com/rogerq/linux/commit/9a9cf6a15f779fddf91dba2370627aabf19aeff5
> https://github.com/rogerq/linux/commit/c87e8fa5b14f156a91883fd506e9dd8f7ccf95cf
> https://github.com/rogerq/linux/commit/d9cdd25e8c3878292d7f4180af8d3ac42b9645c4
> 
> 

cheers,
-roger
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