[U-Boot] Running mx6qsabrelite at 1Gz with Freescale kernel rel_imx_3.0.35_4.1.0

[Stefano Babic]

Hi Thierry,


On 18/03/2014 12:28, tbultel at free.fr wrote:
> 
> 
> Hi,
> 
> I am working on a board (AMOS820 from Via) based on the mx6qsabrelite.
> 
> The BSP provided by the manufacturer is quite old.
> I managed to port it from Freescale uboot-imx rel_imx_3.0.35_4.1.0 to u-boot
> mainline, and basically the latest issue I have is the cpu frequency.
> 
> The kernel I use is the rel_imx_3.0.35_4.1.0 as well (same tag name)
> 
> With the old u-boot, it runs at 1Ghz because the BSP explicitly has a call to
> 
> clk_config(CONFIG_REF_CLK_FREQ, 1000, CPU_CLK);
> 
> With the new u-boot, it runs at default freq which is 800Mhz (at least, what I
> guess from the Bogomips because no other log says it)

It is can taken as reference, but checking the BogoMIPS is not the right
way to proof it. You should take a look at the CCM registers when Linux
is running ( CCM_ANALOG_PLL_ARM).

> I have attempted to pass "arm_freq=1000" to the boot args but that does not
> change anything.

Well, this is a kernel issue, and related to an ancient version.

> 
> My concern is that clk_config does not seem to be available anymore, there is
> get_mcu_main_clk but no set routine.

It was never available in mainline.

> I wonder if it is intentional, I could write a set routine but I wonder if it
> could be accepted as a patch.

Why not ? All patches are discussed here and if it makes sense to merge
it, it will be merged.

Best regards,
Stefano Babic

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