On 7/01/19 12:11 PM, BOUGH CHEN wrote:
> For some eMMC, after switch to HS400ES mode, it need to config the strobe
> dll target dealy even if the clock is 50MHZ or 25MHz, otherwise will meet
> CMD index/crc error when send CMD13 to check the switch status.
>
> [ 2.473915] IRQ status 0x000a8001
> [ 2.473934] mmc2: mmc_select_hs400es failed, error -84
> [ 2.473938] mmc2: error -84 whilst initialising MMC card
>
> Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-esdhc-imx.c | 55 +++++++++++++-----------------
> 1 file changed, 24 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index cf187f8dbc6c..0489b60b8eb4 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -141,9 +141,6 @@
> /* The IP supports HS400 mode */
> #define ESDHC_FLAG_HS400 BIT(9)
>
> -/* A clock frequency higher than this rate requires strobe dll control */
> -#define ESDHC_STROBE_DLL_CLK_FREQ 100000000
> -
> struct esdhc_soc_data {
> u32 flags;
> };
> @@ -907,39 +904,35 @@ static int esdhc_change_pinstate(struct sdhci_host *host,
> * edge of data_strobe line. Due to the time delay between CLK line and
> * data_strobe line, if the delay time is larger than one clock cycle,
> * then CLK and data_strobe line will be misaligned, read error shows up.
> - * So when the CLK is higher than 100MHz, each clock cycle is short enough,
> - * host should configure the delay target.
> */
> static void esdhc_set_strobe_dll(struct sdhci_host *host)
> {
> u32 v;
>
> - if (host->mmc->actual_clock > ESDHC_STROBE_DLL_CLK_FREQ) {
> - /* disable clock before enabling strobe dll */
> - writel(readl(host->ioaddr + ESDHC_VENDOR_SPEC) &
> - ~ESDHC_VENDOR_SPEC_FRC_SDCLK_ON,
> - host->ioaddr + ESDHC_VENDOR_SPEC);
> -
> - /* force a reset on strobe dll */
> - writel(ESDHC_STROBE_DLL_CTRL_RESET,
> - host->ioaddr + ESDHC_STROBE_DLL_CTRL);
> - /*
> - * enable strobe dll ctrl and adjust the delay target
> - * for the uSDHC loopback read clock
> - */
> - v = ESDHC_STROBE_DLL_CTRL_ENABLE |
> - (7 << ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_SHIFT);
> - writel(v, host->ioaddr + ESDHC_STROBE_DLL_CTRL);
> - /* wait 1us to make sure strobe dll status register stable */
> - udelay(1);
> - v = readl(host->ioaddr + ESDHC_STROBE_DLL_STATUS);
> - if (!(v & ESDHC_STROBE_DLL_STS_REF_LOCK))
> - dev_warn(mmc_dev(host->mmc),
> - "warning! HS400 strobe DLL status REF not lock!\n");
> - if (!(v & ESDHC_STROBE_DLL_STS_SLV_LOCK))
> - dev_warn(mmc_dev(host->mmc),
> - "warning! HS400 strobe DLL status SLV not lock!\n");
> - }
> + /* disable clock before enabling strobe dll */
> + writel(readl(host->ioaddr + ESDHC_VENDOR_SPEC) &
> + ~ESDHC_VENDOR_SPEC_FRC_SDCLK_ON,
> + host->ioaddr + ESDHC_VENDOR_SPEC);
> +
> + /* force a reset on strobe dll */
> + writel(ESDHC_STROBE_DLL_CTRL_RESET,
> + host->ioaddr + ESDHC_STROBE_DLL_CTRL);
> + /*
> + * enable strobe dll ctrl and adjust the delay target
> + * for the uSDHC loopback read clock
> + */
> + v = ESDHC_STROBE_DLL_CTRL_ENABLE |
> + (7 << ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_SHIFT);
> + writel(v, host->ioaddr + ESDHC_STROBE_DLL_CTRL);
> + /* wait 1us to make sure strobe dll status register stable */
> + udelay(1);
> + v = readl(host->ioaddr + ESDHC_STROBE_DLL_STATUS);
> + if (!(v & ESDHC_STROBE_DLL_STS_REF_LOCK))
> + dev_warn(mmc_dev(host->mmc),
> + "warning! HS400 strobe DLL status REF not lock!\n");
> + if (!(v & ESDHC_STROBE_DLL_STS_SLV_LOCK))
> + dev_warn(mmc_dev(host->mmc),
> + "warning! HS400 strobe DLL status SLV not lock!\n");
> }
>
> static void esdhc_reset_tuning(struct sdhci_host *host)
>
