I'm experimenting with a nitrogen board with an i.mx6 dl. By default the cpu frequency is set to 800 Mhz, I would like to change it to 1Ghz, which is the maximum supported frequency of the mounted component.
In order to accomplish this I've added an entry in the dcd table to adjust the DIV_SELECT in the Analog ARM PLL control Register:
DATA 4, 0x020C8000, 0x00002054
This should set the divider to 0x54 = 84, which should bring the arm pll frequency to 24 * 84 / 2 = 1008.
This is working when I load u-boot through the usb serial interface (using imx usb loader) :
U-Boot 2013.10 (Dec 19 2013 - 10:37:42)
CPU: Freescale i.MX6DL rev1.0 at 1008 MHz
Reset cause: POR
DRAM: 1 GiB
MMC: FSL_SDHC: 0, FSL_SDHC: 1
SF: Detected SST25VF016B with page size 256 Bytes, erase size 4 KiB, total 2 MiB
auto-detected panel HDMI
Display: HDMI (1024x768)
Net: using phy at 6
Hit any key to stop autoboot: 0
However, when I program the same u-boot in the spi flash, the cpu fails to boot.
Any hints on how I can get the cpu booting at the requested frequency from the spi flash ?