From e3ab3078dca6f84c40ed39830ff351015e6b3914 Mon Sep 17 00:00:00 2001 From: Markus Niebel Date: Thu, 5 Sep 2013 15:31:20 +0200 Subject: [PATCH] MCI: imx-esdhc: implement workaround for errata ENGcm12360 At least i.MX53 has errata ENGcm12360: Occurs when a pending command which issues busy is completed. For a command with R1b response, the proper software sequence is to poll the DLA for R1b commands to determine busy state completion. The DLA polling is not working properly for the ESDHC module. This is relevant for all eSDHC ports (eSDHC1-4 ports) DLA bit in PRSSTAT register cannot be polled to wait for busy state completion. Updated block guide to reflect that DLA is not applicable to detect busy state, instead, should poll bit 24 in PRSSTAT register (DLSL[0] bit) to check that wait busy state is over. Signed-off-by: Markus Niebel Signed-off-by: Sascha Hauer --- drivers/mci/imx-esdhc.c | 15 +++++++++++++++ drivers/mci/sdhci.h | 1 + 2 files changed, 16 insertions(+) diff --git a/drivers/mci/imx-esdhc.c b/drivers/mci/imx-esdhc.c index 8cf3e641c..8da7097c4 100644 --- a/drivers/mci/imx-esdhc.c +++ b/drivers/mci/imx-esdhc.c @@ -266,6 +266,21 @@ esdhc_send_cmd(struct mci_host *mci, struct mci_cmd *cmd, struct mci_data *data) if (irqstat & IRQSTAT_CTOE) return -ETIMEDOUT; + /* Workaround for ESDHC errata ENGcm03648 / ENGcm12360 */ + if (!data && (cmd->resp_type & MMC_RSP_BUSY)) { + /* + * Poll on DATA0 line for cmd with busy signal for + * timout / 10 usec since DLA polling can be insecure. + */ + ret = wait_on_timeout(2500 * MSECOND, + (esdhc_read32(regs + SDHCI_PRESENT_STATE) & PRSSTAT_DAT0)); + + if (ret) { + dev_err(host->dev, "timeout PRSSTAT_DAT0\n"); + return -ETIMEDOUT; + } + } + /* Copy the response to the response buffer */ if (cmd->resp_type & MMC_RSP_136) { u32 cmdrsp3, cmdrsp2, cmdrsp1, cmdrsp0; diff --git a/drivers/mci/sdhci.h b/drivers/mci/sdhci.h index 2c8b6f521..b67818485 100644 --- a/drivers/mci/sdhci.h +++ b/drivers/mci/sdhci.h @@ -77,6 +77,7 @@ #define IRQSTATEN_TC 0x00000002 #define IRQSTATEN_CC 0x00000001 +#define PRSSTAT_DAT0 0x01000000 #define PRSSTAT_CLSL 0x00800000 #define PRSSTAT_WPSPL 0x00080000 #define PRSSTAT_CDPL 0x00040000