From d9370424c9482d0ca2722627309c6f6bae131d97 Mon Sep 17 00:00:00 2001 From: Haibo Chen Date: Tue, 18 Apr 2017 18:05:31 +0800 Subject: [PATCH] mmc: sdhci-esdhc-imx: reset tuning circuit when power on mmc card USDHC tuning circuit should be reset before every time card enumeration or re-enumeration. SD3.0 card need tuning. For SDR104 card, when system suspend in standby mode, and then resume back, the IO timing is still SDR104(tuned) which may result in card re-enumeration fail in low card speed(400khz) for some cards. And we did meet the issue that in certain probability, SDR104 card meet mmc command CRC/Timeout error when send CMD2 during mmc bus resume. This patch reset the tuning circuit when the ios timing is MMC_TIMING_LEGACY/MMC_TIMING_MMC_HS/MMC_TIMING_SD_HS, which means both mmc_power_up() and mmc_power_off() will reset the tuning circuit. Signed-off-by: Haibo Chen Acked-by: Dong Aisheng Acked-by: Adrian Hunter Signed-off-by: Ulf Hansson --- drivers/mmc/host/sdhci-esdhc-imx.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index abad67aeabdd..23d8b8a73ae9 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -889,6 +889,28 @@ static void esdhc_set_strobe_dll(struct sdhci_host *host) } } +static void esdhc_reset_tuning(struct sdhci_host *host) +{ + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); + struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host); + u32 ctrl; + + /* Rest the tuning circurt */ + if (esdhc_is_usdhc(imx_data)) { + if (imx_data->socdata->flags & ESDHC_FLAG_MAN_TUNING) { + ctrl = readl(host->ioaddr + ESDHC_MIX_CTRL); + ctrl &= ~ESDHC_MIX_CTRL_SMPCLK_SEL; + ctrl &= ~ESDHC_MIX_CTRL_FBCLK_SEL; + writel(ctrl, host->ioaddr + ESDHC_MIX_CTRL); + writel(0, host->ioaddr + ESDHC_TUNE_CTRL_STATUS); + } else if (imx_data->socdata->flags & ESDHC_FLAG_STD_TUNING) { + ctrl = readl(host->ioaddr + SDHCI_ACMD12_ERR); + ctrl &= ~ESDHC_MIX_CTRL_SMPCLK_SEL; + writel(ctrl, host->ioaddr + SDHCI_ACMD12_ERR); + } + } +} + static void esdhc_set_uhs_signaling(struct sdhci_host *host, unsigned timing) { u32 m; @@ -932,6 +954,10 @@ static void esdhc_set_uhs_signaling(struct sdhci_host *host, unsigned timing) host->ops->set_clock(host, host->clock); esdhc_set_strobe_dll(host); break; + case MMC_TIMING_LEGACY: + default: + esdhc_reset_tuning(host); + break; } esdhc_change_pinstate(host, timing); -- 2.20.1