Hello Heiko, Thank you for your reply. I have just noticed that the patches have already been pulled into arm/next so I guess I am quite late with my comments. I'd like to apologize for this; apparently I need another email filter that also filters for messages containing "am1808" and not only "da850" ;-)
Which brings me to my next point: AFAIK Texas Instruments's AM18xx SoCs, their OMAP-L138, and their DA850 based devices basically differ only in the DSP/PRU part of the device. If you are (like in u-boot) only interested in the ARM part of chip, they are basically the same device. For some reason the Linux kernel and u-boot support for all these devices is labelled da850... Although I have no hardware to test it, I guess that your DDR memory controller initialization code could be used for the OMAP-L138 and the corresponding Davinci device as well. So since all code in u-boot for the entire device family is labelled da850... I guess your DDR initialization functions should get this prefix as well for consistency. Any comments from the maintainers/TI employees who know these devices better than I do?
On Mon, Sep 26, 2011 at 10:28 AM, Heiko Schocher hs@denx.de wrote:
Hello Christian,
Christian Riesch wrote:
Heiko, I am looking forward to see these patches in mainline u-boot. My custom board also directly boots from NOR, so I think there is a lot I can re-use for my board.
Thats the goal ;-)
I have one question, please see below:
[...]
+void am1808_lpc_transition(unsigned char pscnum, unsigned char module,
- unsigned char domain, unsigned char state)
+{
[...]
- /* Wait for transition to complete */
- while (readl(®->ptstat) & (0x00000001 << domain))
- ;
- /* Wait and verify the state */
- while ((readl(mdstat) & 0x1F) != state)
- ;
+}
There is some similar code in arch/arm/cpu/arm926ejs/davinci/psc.c. Is there any reason why you don't use this code or adapt it for your needs?
No, there is no reason, just missed it! I try the functions in arch/arm/cpu/arm926ejs/davinci/psc.c and if they work, I remove the am1808_lpc_transition function.
Ok. Actually you do LPSC transitions twice in your board configuration, first in the low level initialization in arch/arm/cpu/arm926ejs/davinci/am1808_lowlevel.c (using your own function) and then again in your board initialization in board/enbw/enbw_cmc/enbw_cmc.c (using the code in arch/arm/cpu/arm926ejs/davinci/psc.c). I assume you ran into the same problem as I did with the da850evm board. The UART is used before it is turned on in the board_init() function. A few weeks ago I submitted a patch [1][2] for this issue but did not get any comments on it. Would you mind having a look at it so we could find a common solution for both your configuration and the da850evm?
Regards, Christian
[1] http://lists.denx.de/pipermail/u-boot/2011-September/100352.html [2] http://patchwork.ozlabs.org/patch/113335/