DDR50 tuning is optinally defined in sd 3.0 spec. And i.MX
uSDHC internally already uses a fixed optimized timing for
DDR50, normally does not require tuning for DDR50 mode.
This patch specify a new execute_tuning function for i.MX
uSDHC, do not impact i.MX eSDHC.
Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx>
---
drivers/mmc/host/sdhci-esdhc-imx.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 75a2484..748ac4e 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -818,6 +818,20 @@ static void esdhc_pltfm_set_bus_width(struct sdhci_host *host, int width)
SDHCI_HOST_CONTROL);
}
+static int usdhc_execute_tuning(struct mmc_host *mmc, u32 opcode)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+
+ /*
+ * i.MX uSDHC internally already uses a fixed optimized timing for
+ * DDR50, normally does not require tuning for DDR50 mode.
+ */
+ if (host->timing == MMC_TIMING_UHS_DDR50)
+ return 0;
+
+ return sdhci_execute_tuning(mmc, opcode);
+}
+
static void esdhc_prepare_tuning(struct sdhci_host *host, u32 val)
{
u32 reg;
@@ -1338,6 +1352,12 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
writel(0x0, host->ioaddr + ESDHC_MIX_CTRL);
writel(0x0, host->ioaddr + SDHCI_AUTO_CMD_STATUS);
writel(0x0, host->ioaddr + ESDHC_TUNE_CTRL_STATUS);
+
+ /*
+ * Link usdhc specific mmc_host_ops execute_tuning function,
+ * to replace the standard one in sdhci_ops.
+ */
+ host->mmc_host_ops.execute_tuning = usdhc_execute_tuning;
}
if (imx_data->socdata->flags & ESDHC_FLAG_MAN_TUNING)
--
1.9.1
