mmc: dw_mmc: split out preparation of desc for IDMAC32 and IDMAC64

We intend to add more check for descriptors when
preparing desc. Let's spilt out the separate body
to make the dw_mci_translate_sglist not so lengthy.
After spliting out these two functions, we could
remove dw_mci_translate_sglist and call both of them
when staring idmac.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/dw_mmc.c

@@ -467,14 +467,13 @@ static void dw_mci_dmac_complete_dma(void *arg)
 	}
 }
 
-static void dw_mci_translate_sglist(struct dw_mci *host, struct mmc_data *data,
+static inline void dw_mci_prepare_desc64(struct dw_mci *host,
+					 struct mmc_data *data,
 					 unsigned int sg_len)
 {
 	unsigned int desc_len;
-	int i;
-
-	if (host->dma_64bit_address == 1) {
 	struct idmac_desc_64addr *desc_first, *desc_last, *desc;
+	int i;
 
 	desc_first = desc_last = desc = host->sg_cpu;
 
@@ -517,9 +516,16 @@ static void dw_mci_translate_sglist(struct dw_mci *host, struct mmc_data *data,
 	/* Set last descriptor */
 	desc_last->des0 &= ~(IDMAC_DES0_CH | IDMAC_DES0_DIC);
 	desc_last->des0 |= IDMAC_DES0_LD;
+}
 
-	} else {
+
+static inline void dw_mci_prepare_desc32(struct dw_mci *host,
+					 struct mmc_data *data,
+					 unsigned int sg_len)
+{
+	unsigned int desc_len;
 	struct idmac_desc *desc_first, *desc_last, *desc;
+	int i;
 
 	desc_first = desc_last = desc = host->sg_cpu;
 
@@ -563,16 +569,19 @@ static void dw_mci_translate_sglist(struct dw_mci *host, struct mmc_data *data,
 	desc_last->des0 &= cpu_to_le32(~(IDMAC_DES0_CH |
 				       IDMAC_DES0_DIC));
 	desc_last->des0 |= cpu_to_le32(IDMAC_DES0_LD);
-	}
-
-	wmb(); /* drain writebuffer */
 }
 
 static int dw_mci_idmac_start_dma(struct dw_mci *host, unsigned int sg_len)
 {
 	u32 temp;
 
-	dw_mci_translate_sglist(host, host->data, sg_len);
+	if (host->dma_64bit_address == 1)
+		dw_mci_prepare_desc64(host, host->data, sg_len);
+	else
+		dw_mci_prepare_desc32(host, host->data, sg_len);
+
+	/* drain writebuffer */
+	wmb();
 
 	/* Make sure to reset DMA in case we did PIO before this */
 	dw_mci_ctrl_reset(host, SDMMC_CTRL_DMA_RESET);