mmc: stm32: sdmmc2: add hardware flow control support

The hardware flow control functionality is used to avoid
FIFO underrun (TX mode) and overrun (RX mode) errors.
The behavior is to stop SDMMC_CK during data transfer and
freeze the SDMMC state machines.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
This commit is contained in:
Patrick Delaunay 2018-02-07 17:19:58 +01:00 committed by Tom Rini
parent aa5e3e22f4
commit a72dd8ed95

View File

@ -495,7 +495,8 @@ static int stm32_sdmmc2_set_ios(struct udevice *dev)
if (mmc->bus_width == 8)
clk |= SDMMC_CLKCR_WIDBUS_8;
writel(clk | priv->clk_reg_msk, priv->base + SDMMC_CLKCR);
writel(clk | priv->clk_reg_msk | SDMMC_CLKCR_HWFC_EN,
priv->base + SDMMC_CLKCR);
return 0;
}