• Haibo Chen's avatar
    arm64: dts: imx93: assign usdhc[1..3] root clock to 400MHz · 45bf3c0e
    Haibo Chen authored
    1. Config SDHC1 clock 400MHz to support eMMC HS400ES mode
    2. The original usdhc2 and usdhc3 root clock is 200MHz. Then WIFI
    on usdhc3 at SDR104 mode can work under 200MHz. But if imx93 work
    under Low Drive mode, the usdhc3 pad signal is not good under 200MHz,
    SDR104 mode can't work stable. Need to downgrade to 133MHz to let
    WIFI work stable. To cover all the cases, for Norminal Drive mode,
    keep usdhc root at 400MHz, then card(SD/wifi) can work at SDR104 mode
    under 200MHz to get the best performance. For Low Drive mode,
    bootloader need override usdhc root clock to 266MHz, and the
    card(SD/wifi) work at SDR104 mode under 133MHz, can work stable.
    Reviewed-by: default avatarSherry Sun <sherry.sun@nxp.com>
    Signed-off-by: default avatarHaibo Chen <haibo.chen@nxp.com>
    Signed-off-by: default avatarPeng Fan <peng.fan@nxp.com>
    Signed-off-by: default avatarShawn Guo <shawnguo@kernel.org>
    45bf3c0e
imx93.dtsi 38.3 KB