[PATCH 0/4] HS400 and HS400ES support for Exynos DW-MMC drivers

[Henrik Grimler]

Hi Kaustabh,

On Mon, 2026-04-27 at 11:22 +0530, Kaustabh Chakraborty wrote:
> Since upstream dts version v7.0+, Exynos 7870 devices have an
> explicit
> `bus-width = <8>` property. This results in the U-Boot driver trying
> to
> initialize the HS400 mode, which appears to fail. The HS400 support
> added in the DW-MMC Exynos driver appears to have an incomplete init
> sequence.
> 
> This patch series adds the missing pieces to enable HS400 support,
> and
> additionally adds support for HS400ES too.

Seems like exynos5422-odroid-xu4 can support hs400 as well based on
Hardkernel's device trees [1]. I will try to test on that device during
the week to get some more test coverage for this series.

[1]
https://github.com/hardkernel/linux/blob/odroidxu4-6.1.y/arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi#L491

Best regards,
Henrik Grimler

> The last patch in the series also enables HS400ES support in the
> exynos-mobile defconfig.
> 
> Signed-off-by: Kaustabh Chakraborty <kauschluss at disroot.org>
> ---
> Kaustabh Chakraborty (4):
>       mmc: exynos_dw_mmc: add proper init sequence for HS400 support
>       mmc: dw_mmc: setup set_enhanced_strobe ops in driver
>       mmc: exynos_dw_mmc: add support for HS400ES
>       configs: exynos-mobile: enable support for HS400ES in MMC
> driver
> 
>  arch/arm/mach-exynos/include/mach/dwmmc.h |  5 ++
>  configs/exynos-mobile_defconfig           |  1 +
>  drivers/mmc/dw_mmc.c                      | 19 +++++++
>  drivers/mmc/exynos_dw_mmc.c               | 88
> ++++++++++++++++++++++++++++++-
>  include/dwmmc.h                           | 10 ++++
>  5 files changed, 121 insertions(+), 2 deletions(-)
> ---
> base-commit: 9f61fd5b80a43ae20ba115e3a2933d47d720ab82
> change-id: 20260427-dwmmc-exynos-hs400-es-b77009a808ce
> 
> Best regards,
> --  
> Kaustabh Chakraborty <kauschluss at disroot.org>