From 0d58864bf3472f8390e0c0a33bd875c7eec868bd Mon Sep 17 00:00:00 2001 From: Tony Lin Date: Thu, 11 Aug 2011 16:45:59 -0400 Subject: [PATCH] mmc: esdhc-imx: fix card interrupt loss on freescale eSDHC Apply a workaround for the imx eSDHC controller to avoid missing card interrupts. This makes SDIO work. Signed-off-by: Tony Lin Signed-off-by: Chris Ball --- drivers/mmc/host/sdhci-esdhc-imx.c | 40 +++++++++++++++++++++++------- 1 file changed, 31 insertions(+), 9 deletions(-) diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index 9ebfb4b482f5..0e9780f5a4a9 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -27,6 +27,7 @@ #include "sdhci-pltfm.h" #include "sdhci-esdhc.h" +#define SDHCI_CTRL_D3CD 0x08 /* VENDOR SPEC register */ #define SDHCI_VENDOR_SPEC 0xC0 #define SDHCI_VENDOR_SPEC_SDIO_QUIRK 0x00000002 @@ -141,13 +142,32 @@ static void esdhc_writel_le(struct sdhci_host *host, u32 val, int reg) struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct pltfm_imx_data *imx_data = pltfm_host->priv; struct esdhc_platform_data *boarddata = &imx_data->boarddata; - - if (unlikely((reg == SDHCI_INT_ENABLE || reg == SDHCI_SIGNAL_ENABLE) - && (boarddata->cd_type == ESDHC_CD_GPIO))) - /* - * these interrupts won't work with a custom card_detect gpio - */ - val &= ~(SDHCI_INT_CARD_REMOVE | SDHCI_INT_CARD_INSERT); + u32 data; + + if (unlikely(reg == SDHCI_INT_ENABLE || reg == SDHCI_SIGNAL_ENABLE)) { + if (boarddata->cd_type == ESDHC_CD_GPIO) + /* + * These interrupts won't work with a custom + * card_detect gpio (only applied to mx25/35) + */ + val &= ~(SDHCI_INT_CARD_REMOVE | SDHCI_INT_CARD_INSERT); + + if (val & SDHCI_INT_CARD_INT) { + /* + * Clear and then set D3CD bit to avoid missing the + * card interrupt. This is a eSDHC controller problem + * so we need to apply the following workaround: clear + * and set D3CD bit will make eSDHC re-sample the card + * interrupt. In case a card interrupt was lost, + * re-sample it by the following steps. + */ + data = readl(host->ioaddr + SDHCI_HOST_CONTROL); + data &= ~SDHCI_CTRL_D3CD; + writel(data, host->ioaddr + SDHCI_HOST_CONTROL); + data |= SDHCI_CTRL_D3CD; + writel(data, host->ioaddr + SDHCI_HOST_CONTROL); + } + } if (unlikely((imx_data->flags & ESDHC_FLAG_MULTIBLK_NO_INT) && (reg == SDHCI_INT_STATUS) @@ -217,8 +237,10 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg) */ return; case SDHCI_HOST_CONTROL: - /* FSL messed up here, so we can just keep those two */ - new_val = val & (SDHCI_CTRL_LED | SDHCI_CTRL_4BITBUS); + /* FSL messed up here, so we can just keep those three */ + new_val = val & (SDHCI_CTRL_LED | \ + SDHCI_CTRL_4BITBUS | \ + SDHCI_CTRL_D3CD); /* ensure the endianess */ new_val |= ESDHC_HOST_CONTROL_LE; /* DMA mode bits are shifted */ -- 2.20.1