[U-Boot-Users] Sequoia uart support looks to be misconfigured

[U-Boot-Users] Sequoia uart support looks to be misconfigured

[Steven A. Falco]

I am looking at U-Boot version "DENX-v1.3.3" for the AMCC Sequoia board
(PPC440EPx).

The uart gpio configuration doesn't appear to match the schematics. 
sequoia.h has the following GPIO settings:

{GPIO1_BASE, GPIO_OUT, GPIO_ALT3, GPIO_OUT_1}, /* GPIO34 UART0_DCD_N   
UART1_DSR_CTS_N    UART2_SOUT*/ \
{GPIO1_BASE, GPIO_IN , GPIO_ALT3, GPIO_OUT_0}, /* GPIO35
UART0_8PIN_DSR_N UART1_RTS_DTR_N UART2_SIN*/ \
{GPIO1_BASE, GPIO_IN , GPIO_ALT3, GPIO_OUT_0}, /* GPIO36
UART0_8PIN_CTS_N EBC_DATA(0)    UART3_SIN*/ \
{GPIO1_BASE, GPIO_BI , GPIO_ALT2, GPIO_OUT_0}, /* GPIO37 UART0_RTS_N   
EBC_DATA(1)    UART3_SOUT*/ \

These look wrong.  For example, GPIO34 (ball C28) is wired as CTS
according to the Sequoia schematic.  So, shouldn't it be GPIO_ALT2
rather than GPIO_ALT3?  Similarly, GPIO35 (ball C29) should be RTS,
which is also GPIO_ALT2 rather than GPIO_ALT3.

GPIO36 (ball A29) is also a CTS signal, so I think this should be
GPIO_ALT1, not GPIO_ALT3.  Finally, GPIO37 (ball B29) is another RTS
signal, so it should be GPIO_ALT1, not GPIO_ALT2.

One final comment.  In order to use two uarts, SDR0_PFC1[U0IM] must be
set to 1.  To select the RTS/CTS function for the first uart,
SDR0_PFC1[U0ME] must be set to 1.  Yet, I have not found any place in
the sequoia initialization code where these bits are set.  So, I think
the board is actually running with one uart in 8-pin mode rather than
two uarts each in 4-pin mode.

I'd appreciate it if someone else could take a look at this, and comment
on my concerns.

    Steve