[PATCH 07/42] mmc: dw_mmc: Extract FIFO data transfer into a separate routine

[Sam Protsenko]

FIFO data transfer is implemented as quite a massive chunk of code.
Extract it into a dedicated function to make dwmci_data_transfer()
easier to read and reduce the indentation level of the code.

No functional change.

Signed-off-by: Sam Protsenko <semen.protsenko at linaro.org>
---
 drivers/mmc/dw_mmc.c | 107 +++++++++++++++++++++----------------------
 1 file changed, 53 insertions(+), 54 deletions(-)

diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
index 40b9b034f793..144f29f09240 100644
--- a/drivers/mmc/dw_mmc.c
+++ b/drivers/mmc/dw_mmc.c
@@ -140,25 +140,67 @@ static unsigned int dwmci_get_timeout(struct mmc *mmc, const unsigned int size)
 	return timeout;
 }
 
-static int dwmci_data_transfer(struct dwmci_host *host, struct mmc_data *data)
+static int dwmci_data_transfer_fifo(struct dwmci_host *host,
+				    struct mmc_data *data, u32 mask)
 {
-	struct mmc *mmc = host->mmc;
+	const u32 fifo_depth = (((host->fifoth_val & RX_WMARK_MASK) >>
+				 RX_WMARK_SHIFT) + 1) * 2;
+	const u32 int_rx = mask & (DWMCI_INTMSK_RXDR | DWMCI_INTMSK_DTO);
+	const u32 int_tx = mask & DWMCI_INTMSK_TXDR;
 	int ret = 0;
-	u32 timeout, mask, size, i, len = 0;
-	u32 *buf = NULL;
-	ulong start = get_timer(0);
-	u32 fifo_depth = (((host->fifoth_val & RX_WMARK_MASK) >>
-			    RX_WMARK_SHIFT) + 1) * 2;
+	u32 len = 0, size, i;
+	u32 *buf;
+
+	size = (data->blocksize * data->blocks) / 4;
+	if (!host->fifo_mode || !size)
+		return 0;
 
-	size = data->blocksize * data->blocks;
 	if (data->flags == MMC_DATA_READ)
 		buf = (unsigned int *)data->dest;
 	else
 		buf = (unsigned int *)data->src;
 
-	timeout = dwmci_get_timeout(mmc, size);
+	if (data->flags == MMC_DATA_READ && int_rx) {
+		dwmci_writel(host, DWMCI_RINTSTS, int_rx);
+		while (size) {
+			ret = dwmci_fifo_ready(host, DWMCI_FIFO_EMPTY, &len);
+			if (ret < 0)
+				break;
+
+			len = (len >> DWMCI_FIFO_SHIFT) & DWMCI_FIFO_MASK;
+			len = min(size, len);
+			for (i = 0; i < len; i++)
+				*buf++ = dwmci_readl(host, DWMCI_DATA);
+			size = size > len ? (size - len) : 0;
+		}
+	} else if (data->flags == MMC_DATA_WRITE && int_tx) {
+		while (size) {
+			ret = dwmci_fifo_ready(host, DWMCI_FIFO_FULL, &len);
+			if (ret < 0)
+				break;
+
+			len = fifo_depth - ((len >> DWMCI_FIFO_SHIFT) &
+					    DWMCI_FIFO_MASK);
+			len = min(size, len);
+			for (i = 0; i < len; i++)
+				dwmci_writel(host, DWMCI_DATA, *buf++);
+			size = size > len ? (size - len) : 0;
+		}
+		dwmci_writel(host, DWMCI_RINTSTS, DWMCI_INTMSK_TXDR);
+	}
 
-	size /= 4;
+	return ret;
+}
+
+static int dwmci_data_transfer(struct dwmci_host *host, struct mmc_data *data)
+{
+	struct mmc *mmc = host->mmc;
+	int ret = 0;
+	u32 timeout, mask, size;
+	ulong start = get_timer(0);
+
+	size = data->blocksize * data->blocks;
+	timeout = dwmci_get_timeout(mmc, size);
 
 	for (;;) {
 		mask = dwmci_readl(host, DWMCI_RINTSTS);
@@ -169,50 +211,7 @@ static int dwmci_data_transfer(struct dwmci_host *host, struct mmc_data *data)
 			break;
 		}
 
-		if (host->fifo_mode && size) {
-			len = 0;
-			if (data->flags == MMC_DATA_READ &&
-			    (mask & (DWMCI_INTMSK_RXDR | DWMCI_INTMSK_DTO))) {
-				dwmci_writel(host, DWMCI_RINTSTS,
-					     mask & (DWMCI_INTMSK_RXDR |
-						     DWMCI_INTMSK_DTO));
-				while (size) {
-					ret = dwmci_fifo_ready(host,
-							DWMCI_FIFO_EMPTY,
-							&len);
-					if (ret < 0)
-						break;
-
-					len = (len >> DWMCI_FIFO_SHIFT) &
-						    DWMCI_FIFO_MASK;
-					len = min(size, len);
-					for (i = 0; i < len; i++)
-						*buf++ =
-						dwmci_readl(host, DWMCI_DATA);
-					size = size > len ? (size - len) : 0;
-				}
-			} else if (data->flags == MMC_DATA_WRITE &&
-				   (mask & DWMCI_INTMSK_TXDR)) {
-				while (size) {
-					ret = dwmci_fifo_ready(host,
-							DWMCI_FIFO_FULL,
-							&len);
-					if (ret < 0)
-						break;
-
-					len = fifo_depth - ((len >>
-						   DWMCI_FIFO_SHIFT) &
-						   DWMCI_FIFO_MASK);
-					len = min(size, len);
-					for (i = 0; i < len; i++)
-						dwmci_writel(host, DWMCI_DATA,
-							     *buf++);
-					size = size > len ? (size - len) : 0;
-				}
-				dwmci_writel(host, DWMCI_RINTSTS,
-					     DWMCI_INTMSK_TXDR);
-			}
-		}
+		ret = dwmci_data_transfer_fifo(host, data, mask);
 
 		/* Data arrived correctly. */
 		if (mask & DWMCI_INTMSK_DTO) {
-- 
2.39.2