u-boot/board/toradex/colibri-imx6ull
Philippe Schenker 936bf17263 colibri-imx6ull: fix setup of nand gpmi clock
NXP used to setup the gpmi clock root from gpmi_clk in early versions
in their downstream BSP. [1]
However on mainline the gpmi clock root was always setup from enfc
since the beginning of the i.MX 6 series SoCs, which is still the same
today. [2]

NXP followed the mainline approach at some point and changed
setup_gpmi_io_clk to setup gpmi clock root from enfc which left faulty
code behind in our board file. [3]

This commit follows the change of NXP as it improves the performance of
the NAND from ~1.2 MiB/s to ~12 MiB/s. [3]

This change was verified to work in recovery-mode and u-boot loaded
from NAND on all four Colibri iMX6ULL SKUs from Toradex.

The frequency used to read the NAND, measured on RE# (Read Enable):
before this patch: 1.4 MHz
after this patch:   22 MHz
in Linux Kernel:    50 MHz

[1] https://source.codeaurora.org/external/imx/uboot-imx/tree/arch/arm/cpu/armv7/mx6/clock.c?h=nxp/imx_v2016.03_4.1.15_2.0.0_ga#n62
[2] commit 23608e23fd ("i.mx: add the initial support for freescale i.MX6Q processor")
[3] https://source.codeaurora.org/external/imx/uboot-imx/commit/?id=7a82a19ceabfb04bbc1591a67c99751748781c7d

Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
2021-10-20 17:42:55 +02:00
..
colibri-imx6ull.c colibri-imx6ull: fix setup of nand gpmi clock 2021-10-20 17:42:55 +02:00
imximage.cfg doc: update reference to README.imximage 2020-04-16 23:06:54 -04:00
Kconfig imx: Finish migration of IMX_CONFIG to Kconfig 2021-08-31 17:46:37 -04:00
MAINTAINERS toradex: hand over maintainership 2020-12-26 14:56:09 +01:00
Makefile board: toradex: add Colibri iMX6ULL support 2018-07-23 10:12:00 +02:00