[U-Boot] [PATCH 1/1] MPC8541/MPC8555: Enable SS_EN in DDR_SDRAM_CLK_CNLT register

[York Sun]

On 02/13/2015 10:57 AM, Curt Brune wrote:
> According to the MPC8555/MPC8541 reference manual the SS_EN (source
> synchronous enable) bit in the DDR_SDRAM_CLK_CNLT register must be set
> during initialization.
> 
> From section 9.4.1.8 of that manual:
> 
>    Source synchronous enable. This bit field must be set during
>    initialization. See Section 9.6.1, "DDR SDRAM Initialization
>    Sequence," details.
> 
>    0 - Reserved
>    1 - The address and command are sent to the DDR SDRAMs source
>        synchronously.
> 
> In addition, Freescale application note AN2805 is also very clear that
> this bit must be set.
> 
> This patch reverts a change introduced by commit
> 457caecdbca3df21a93abff19eab12dbc61b7897.
> 
> Testing Done:
> 
> Compiled targets CONFIG_TARGET_MPC8555CDS and CONFIG_TARGET_MPC8541CDS
> and inspected the generated assembly code to verify the SS_EN bit was being
> set.  There is one extra instruction emitted:
> 
>   fff9b774: 65 29 80 00  oris    r9,r9,32768
> 
> Compiled the CONFIG_TARGET_MPC8548CDS target and verified that no
> additional instructions were emitted related to this patch.
> 
> Booted an image on a MPC8541 based board successfully.
> 
> Signed-off-by: Curt Brune <curt at cumulusnetworks.com>
> ---

Applied to mpc85xx master, awaiting upstream.

York