Re: [PATCH v2 6/8] board: ti: j721e: Add the missing part of exit retention for k3-ddrss (J7200)

[Thomas Richard <thomas.richard@bootlin.com>]

On 11/7/23 19:18, Tom Rini wrote:
> On Tue, Nov 07, 2023 at 05:18:00PM +0100, Thomas Richard wrote:
> 
>> Add the board specific part of the exit retention sequence for k3-ddrss
>>
>> Based on the work of Gregory CLEMENT <gregory.clement@bootlin.com>
>>
>> Signed-off-by: Thomas Richard <thomas.richard@bootlin.com>
>> Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
> 
> If this ends up being physical board design specific and so someone
> making a new design for this SoC with a custom board layout entirely
> needs something else, we should think harder about what's in
> board_is_resuming() vs what we document the function does. If however,
> this is generic to the SoC and will be needed, it should be folded in
> with the previous patch and the commit message expanded, and the
> documentation part of this series explain clearly what the functions are
> responsible for.
> 

Hi Tom,

Thanks for all these interesting feedback's.

From my point of view, board_is_resuming will work with all j7* SoCs and
all new designs for these SoCs.
This function only read and erase a scratchpad register in the PMIC A.
So it should be ok for all designs which have the PMIC@48.

For the function board_k3_ddrss_lpddr4_release_retention, it's a little
bit more tricky. The sequence is specific to the SOC, but the GPIOs used
are specific to the board.

Regards,

Thomas

-- 
Thomas Richard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com