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>
Currently, the DDR type is retrieved by iteracting inside an array
of possible DDR types.
This may take saveral attempts, which slows the overall U-Boot process
and does not provide a good user experience:
U-Boot SPL 2021.07 (Feb 28 2022 - 06:39:32 +0000)
DDRINFO: Cfg attempt: [ 1/6 ]
DDRINFO(M): mr5-8 [ 0xff000010 ]
DDRINFO(T): mr5-8 [ 0x5000010 ]
resetting ...
U-Boot SPL 2021.07 (Feb 28 2022 - 06:39:32 +0000)
DDRINFO: Cfg attempt: [ 2/6 ]
DDRINFO(M): mr5-8 [ 0xff000010 ]
DDRINFO(T): mr5-8 [ 0x1061010 ]
resetting ...
U-Boot SPL 2021.07 (Feb 28 2022 - 06:39:32 +0000)
DDRINFO: Cfg attempt: [ 3/6 ]
DDRINFO(M): mr5-8 [ 0xff000010 ]
DDRINFO(T): mr5-8 [ 0xff000010 ]
Normal Boot
WDT: Not starting
Trying to boot from MMC2
NOTICE: BL31: v2.5(release):v2.5
NOTICE: BL31: Built : 07:12:44, Jan 24 2022
Improve the boot time by retrieving the correct DDR information from
the EEPROM:
U-Boot SPL 2022.04-rc4-00045-g6d02bc40d58c (Mar 19 2022 - 08:22:29 -0300)
DDRINFO(D): Kingston 4096G
DDRINFO(M): mr5-8 [ 0xff000010 ]
DDRINFO(E): mr5-8 [ 0xff000010 ]
Normal Boot
WDT: Started watchdog@30280000 with servicing (60s timeout)
Trying to boot from MMC2
NOTICE: BL31: v2.5(release):v2.5
NOTICE: BL31: Built : 22:28:11, Mar 15 2022
Based on the original code from Compulab's U-Boot.
Tested on a imx8mm-cl-iot-gate board populated with 4GB of RAM.
Signed-off-by: Fabio Estevam <festevam@denx.de>
