[PATCH v2 4/4] rockchip: sdhci: Add HS400 Enhanced Strobe support for RK3568

[Alper Nebi Yasak]

On 12/01/2022 05:03, 赵仪峰 wrote:
> The Synopsys DWC MSHC for RK3568 and RK3588 need config
> DWCMSHC_EMMC_CONTROL.bit0 = 1 （CARD_IS_EMMC）
> to enable Data Strobe pin for HS400 and HS400ES.
> 
> reference code:
> #define DWCMSHC_EMMC_CONTROL 0x52c
> #define DWCMSHC_CARD_IS_EMMC BIT(0)
> 
> /* set CARD_IS_EMMC bit to enable Data Strobe for HS400 and HS400ES */
> ctrl = sdhci_readw(host, DWCMSHC_EMMC_CONTROL);
> ctrl |= DWCMSHC_CARD_IS_EMMC;
> sdhci_writew(host, ctrl, DWCMSHC_EMMC_CONTROL);

I think I'll do this in rk3568_emmc_phy_init() and set/unset the bit
based on IS_MMC(host->mmc).


(FWIW, it doesn't look like the Linux driver [1] sets this bit.)

[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/mmc/host/sdhci-of-dwcmshc.c?h=master