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mmc: sdhci-esdhc-imx: reset tuning circuit when power on mmc card

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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 <haibo.chen@nxp.com>
Acked-by: Dong Aisheng <aisheng.dong@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Haibo Chen 2017-04-18 18:05:31 +08:00 committed by Ulf Hansson
parent a82d12b8d5
commit d9370424c9
1 changed files with 26 additions and 0 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

26
drivers/mmc/host/sdhci-esdhc-imx.c
View file

@ -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);