u-boot/board/compulab
Rasmus Villemoes 290ffe5788 imx8m: fix reading of DDR4 MR registers
I was trying to employ lpddr4_mr_read() to something similar to what
the imx8mm-cl-iot-gate board is doing for auto-detecting the RAM
type. However, the version in drivers/ddr/imx/imx8m/ddrphy_utils.c
differs from the private one used by that board in how it extracts the
byte value, and I was only getting zeroes. Adding a bit of debug
printf'ing gives me

 tmp = 0x00ffff00
 tmp = 0x00070700
 tmp = 0x00000000
 tmp = 0x00101000

and indeed I was expecting a (combined) value of 0xff070010 (0xff
being Manufacturer ID for Micron). I can't find any documentation that
says how the values are supposed to be read, but clearly the iot-gate
definition is the right one, both for its use case as well as my
imx8mp-based board.

So lift the private definition of lpddr4_mr_read() from the
imx8mm-cl-iot-gate board code to ddrphy_utils.c, and add a declaration
in the ddr.h header where e.g. get_trained_CDD() is already declared.

This has only been compile-tested for the imx8mm-cl-iot-gate
board (since I don't have the hardware), but since I've merely moved
its definition of lpddr4_mr_read(), I'd be surprised if it changed
anything for that board.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Tested-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
Reviewed-by: Fabio Estevam <festevam@denx.de>
2022-05-20 09:30:28 +02:00
..
cl-som-imx7 Remove CONFIG_SYS_MMC_IMG_LOAD_PART from CONFIG namespace 2021-12-27 08:41:38 -05:00
cm_fx6 arm: Disable ATAGs support 2021-09-07 16:22:30 -04:00
cm_t43 WS cleanup: remove trailing empty lines 2021-09-30 08:08:56 -04:00
cm_t335 reset: Remove addr parameter from reset_cpu() 2021-03-02 14:03:02 -05:00
common compulab: Clean up some unused symbols 2021-09-27 21:38:34 -04:00
imx8mm-cl-iot-gate imx8m: fix reading of DDR4 MR registers 2022-05-20 09:30:28 +02:00
trimslice SPDX: Convert all of our single license tags to Linux Kernel style 2018-05-07 09:34:12 -04:00