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i.MX 8MQuad EVK, change DDR frequency

Question asked by Jeff Kim on Jul 10, 2018
Latest reply on Jul 10, 2018 by igorpadykov

Hello,

 

My DISTRO version is 4.9.88_2.0.0. I'm going to change DDR(lpddr4) frequency. Reference manual mentioned fsl-imx8mq.dtsi, busfreq-imx8mq.c and busfreq-imx.h are related with it. I'm not familiar with this program yet. Can I refer to any example code about bus frequency modification?

In addtition, below folder arch/arm/mach-imx is also introduced in reference manual. Frequency related files seem not related with lpddr4 for i.MX 8Mquad EVK. Can I ignore this mach-imx folder?

In case, I do compilation with modified source code, I would have to burn SD card again with new image file.

Is there any way to change DDR frequency w/o compilation at u-boot prompt or whatever?

 

Best Regards,

Jeff

 

user@TW-JEFF:~/imx-yocto-bsp/build-wayland/tmp/work/aarch64-poky-linux/linux-libc-headers/4.9-r0/git/arch/arm/mach-imx$ ls -l *freq*
-rw-r--r-- 1 user user 20547  六  27 16:09 busfreq_ddr3.c
-rw-r--r-- 1 user user 40093  六  27 16:09 busfreq-imx.c
-rw-r--r-- 1 user user 10265  六  27 16:09 busfreq_lpddr2.c
-rw-r--r-- 1 user user 21474  六  27 16:09 ddr3_freq_imx6.S
-rw-r--r-- 1 user user 15519  六  27 16:09 ddr3_freq_imx6sx.S
-rw-r--r-- 1 user user 10549  六  27 16:09 ddr3_freq_imx7d.S
-rw-r--r-- 1 user user 15002  六  27 16:09 lpddr2_freq_imx6q.S
-rw-r--r-- 1 user user 12219  六  27 16:09 lpddr2_freq_imx6.S
-rw-r--r-- 1 user user  9442  六  27 16:09 lpddr2_freq_imx6sll.S
-rw-r--r-- 1 user user 10005  六  27 16:09 lpddr2_freq_imx6sx.S
-rw-r--r-- 1 user user  8336  六  27 16:09 lpddr3_freq_imx.S

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