[U-Boot] [PATCH] mmc: dwmmc: Poll for iDMAC TX/RX interrupt

[Ley Foon Tan]

Poll for iDMAC TX/RX interrupt before disable DMA.
This to prevent disable DMA before data is transfer
completed.

Signed-off-by: Ley Foon Tan <ley.foon.tan at intel.com>
---
 drivers/mmc/dw_mmc.c |   19 +++++++++++++++++++
 include/dwmmc.h      |    7 +++++++
 2 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
index 7544b84..93a836e 100644
--- a/drivers/mmc/dw_mmc.c
+++ b/drivers/mmc/dw_mmc.c
@@ -12,6 +12,7 @@
 #include <memalign.h>
 #include <mmc.h>
 #include <dwmmc.h>
+#include <wait_bit.h>
 
 #define PAGE_SIZE 4096
 
@@ -55,6 +56,9 @@ static void dwmci_prepare_data(struct dwmci_host *host,
 
 	dwmci_wait_reset(host, DWMCI_CTRL_FIFO_RESET);
 
+	/* Clear IDMAC interrupt */
+	dwmci_writel(host, DWMCI_IDSTS, 0xFFFFFFFF);
+
 	data_start = (ulong)cur_idmac;
 	dwmci_writel(host, DWMCI_DBADDR, (ulong)cur_idmac);
 
@@ -340,6 +344,18 @@ static int dwmci_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
 
 		/* only dma mode need it */
 		if (!host->fifo_mode) {
+			if (data->flags == MMC_DATA_READ)
+				mask = DWMCI_IDINTEN_RI;
+			else
+				mask = DWMCI_IDINTEN_TI;
+			ret = wait_for_bit_le32(host->ioaddr + DWMCI_IDSTS,
+						mask, true, 1000, false);
+			if (ret)
+				debug("%s: DWMCI_IDINTEN mask 0x%x timeout.\n",
+				      __func__, mask);
+			/* clear interrupts */
+			dwmci_writel(host, DWMCI_IDSTS, DWMCI_IDINTEN_MASK);
+
 			ctrl = dwmci_readl(host, DWMCI_CTRL);
 			ctrl &= ~(DWMCI_DMA_EN);
 			dwmci_writel(host, DWMCI_CTRL, ctrl);
@@ -494,6 +510,9 @@ static int dwmci_init(struct mmc *mmc)
 	dwmci_writel(host, DWMCI_CLKENA, 0);
 	dwmci_writel(host, DWMCI_CLKSRC, 0);
 
+	if (!host->fifo_mode)
+		dwmci_writel(host, DWMCI_IDINTEN, DWMCI_IDINTEN_MASK);
+
 	return 0;
 }
 
diff --git a/include/dwmmc.h b/include/dwmmc.h
index 4ceda5e..f06720d 100644
--- a/include/dwmmc.h
+++ b/include/dwmmc.h
@@ -130,6 +130,13 @@
 /* UHS register */
 #define DWMCI_DDR_MODE	(1 << 16)
 
+/* Internal IDMAC interrupt defines */
+#define DWMCI_IDINTEN_RI		BIT(1)
+#define DWMCI_IDINTEN_TI		BIT(0)
+
+#define DWMCI_IDINTEN_MASK	(DWMCI_IDINTEN_TI | \
+				 DWMCI_IDINTEN_RI)
+
 /* quirks */
 #define DWMCI_QUIRK_DISABLE_SMU		(1 << 0)
 
-- 
1.7.1