[U-Boot] [PATCH] ENGR00299356 ARM:imx6 Fix USDHC driver bug in PIO mode

[Ye.Li]

When configure the USDHC driver to PIO mode by defining
"CONFIG_SYS_FSL_ESDHC_USE_PIO", the SD/MMC read and write will fail.

Two bugs in the driver to cause the issue:
1. The read buffer was invalidated after reading from DATAPORT register,
which should be only applied to DMA mode. The valid data in cache was
overwritten by physical memory.
2. The watermarks are not set in PIO mode, will cause according state not
be set.

Signed-off-by: Ye.Li <B37916 at freescale.com>
---
 drivers/mmc/fsl_esdhc.c |   23 +++++++++--------------
 1 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
index b5f6d62..bd0399a 100644
--- a/drivers/mmc/fsl_esdhc.c
+++ b/drivers/mmc/fsl_esdhc.c
@@ -190,7 +190,7 @@ static int esdhc_setup_data(struct mmc *mmc, struct mmc_data *data)
 	int timeout;
 	struct fsl_esdhc_cfg *cfg = (struct fsl_esdhc_cfg *)mmc->priv;
 	struct fsl_esdhc *regs = (struct fsl_esdhc *)cfg->esdhc_base;
-#ifndef CONFIG_SYS_FSL_ESDHC_USE_PIO
+
 	uint wml_value;
 
 	wml_value = data->blocksize/4;
@@ -200,12 +200,15 @@ static int esdhc_setup_data(struct mmc *mmc, struct mmc_data *data)
 			wml_value = WML_RD_WML_MAX_VAL;
 
 		esdhc_clrsetbits32(&regs->wml, WML_RD_WML_MASK, wml_value);
+#ifndef CONFIG_SYS_FSL_ESDHC_USE_PIO
 		esdhc_write32(&regs->dsaddr, (u32)data->dest);
+#endif
 	} else {
+#ifndef CONFIG_SYS_FSL_ESDHC_USE_PIO
 		flush_dcache_range((ulong)data->src,
 				   (ulong)data->src+data->blocks
 					 *data->blocksize);
-
+#endif
 		if (wml_value > WML_WR_WML_MAX)
 			wml_value = WML_WR_WML_MAX_VAL;
 		if ((esdhc_read32(&regs->prsstat) & PRSSTAT_WPSPL) == 0) {
@@ -215,19 +218,10 @@ static int esdhc_setup_data(struct mmc *mmc, struct mmc_data *data)
 
 		esdhc_clrsetbits32(&regs->wml, WML_WR_WML_MASK,
 					wml_value << 16);
+#ifndef CONFIG_SYS_FSL_ESDHC_USE_PIO
 		esdhc_write32(&regs->dsaddr, (u32)data->src);
+#endif
 	}
-#else	/* CONFIG_SYS_FSL_ESDHC_USE_PIO */
-	if (!(data->flags & MMC_DATA_READ)) {
-		if ((esdhc_read32(&regs->prsstat) & PRSSTAT_WPSPL) == 0) {
-			printf("\nThe SD card is locked. "
-				"Can not write to a locked card.\n\n");
-			return TIMEOUT;
-		}
-		esdhc_write32(&regs->dsaddr, (u32)data->src);
-	} else
-		esdhc_write32(&regs->dsaddr, (u32)data->dest);
-#endif	/* CONFIG_SYS_FSL_ESDHC_USE_PIO */
 
 	esdhc_write32(&regs->blkattr, data->blocks << 16 | data->blocksize);
 
@@ -410,9 +404,10 @@ esdhc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data)
 			if (irqstat & DATA_ERR)
 				return COMM_ERR;
 		} while ((irqstat & DATA_COMPLETE) != DATA_COMPLETE);
-#endif
+
 		if (data->flags & MMC_DATA_READ)
 			check_and_invalidate_dcache_range(cmd, data);
+#endif
 	}
 
 	esdhc_write32(&regs->irqstat, -1);
-- 
1.7.4.1