From mboxrd@z Thu Jan 1 00:00:00 1970 From: Haibo Chen Subject: [PATCH] mmc: sdhci-esdhc-imx: reset tuning circuit when power on mmc card Date: Mon, 17 Apr 2017 19:45:38 +0800 Message-ID: <1492429538-14996-1-git-send-email-haibo.chen@nxp.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from mail-db5eur01on0089.outbound.protection.outlook.com ([104.47.2.89]:31568 "EHLO EUR01-DB5-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750776AbdDQLjd (ORCPT ); Mon, 17 Apr 2017 07:39:33 -0400 Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: adrian.hunter@intel.com, ulf.hansson@linaro.org, aisheng.dong@nxp.com Cc: linux-mmc@vger.kernel.org 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 --- 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 abad67a..8960833 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); + u16 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 << 8, 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); -- 1.9.1