[U-Boot] Enabling uart 3 in arndale

[Tomasz Figa]

Hi,

On 16.03.2014 11:42, armdev wrote:
> Dear Michael,
> Thanks for taking out time to extend help.
>
> As per the RefManual the UART is taking the SCLK_UART Clock and as there are 4 channels (4 UARTS).
>
> Following is from the public exynos 5250 manual (http://www.samsung.com/global/business/semiconductor/file/product/Exynos_5_Dual_User_Manaul_Public_REV100-0.pdf)
>
> "Four independent channels with asynchronous and serial input/output ports for general purpose (Channel 0 to 3), and One channel in ISP (ISP-UART Channel 0)
>   …
> 	• Each UART contains a Baud-rate generator, a Transmitter, a Receiver and a Control Unit. The Baud-rate generator uses SCLK_UART."

Each UART block uses independent clock source, i.e. UART0 uses 
SCLK_UART0 and UART3 uses SCLK_UART3.

Do you have MUX_UART3 and DIV_UART3 configured properly? Do you have the 
IP bus clock (CLK_UART3) ungated?

The public manual contains full description of clock tree and clock 
controller registers, so you should be able to figure this out.

Best regards,
Tomasz