memory: renesas-rpc-if: Simplify single/double data register access

For manual write and read, factor out the common access to the first
data register by keeping track of the current data pointer.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/c3b2a8d1a69f1b1e8d1a460148406cfb83e52eb4.1649857740.git.geert+renesas@glider.be
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

drivers/memory/renesas-rpc-if.c

@@ -458,7 +458,7 @@ int rpcif_manual_xfer(struct rpcif *rpc)
 	case RPCIF_DATA_OUT:
 		while (pos < rpc->xferlen) {
 			u32 bytes_left = rpc->xferlen - pos;
-			u32 nbytes, data[2];
+			u32 nbytes, data[2], *p = data;
 
 			smcr = rpc->smcr | RPCIF_SMCR_SPIE;
 
@@ -471,15 +471,9 @@ int rpcif_manual_xfer(struct rpcif *rpc)
 			regmap_write(rpc->regmap, RPCIF_SMENR, smenr);
 
 			memcpy(data, rpc->buffer + pos, nbytes);
-			if (nbytes == 8) {
-				regmap_write(rpc->regmap, RPCIF_SMWDR1,
-					     data[0]);
-				regmap_write(rpc->regmap, RPCIF_SMWDR0,
-					     data[1]);
-			} else {
-				regmap_write(rpc->regmap, RPCIF_SMWDR0,
-					     data[0]);
-			}
+			if (nbytes == 8)
+				regmap_write(rpc->regmap, RPCIF_SMWDR1, *p++);
+			regmap_write(rpc->regmap, RPCIF_SMWDR0, *p);
 
 			regmap_write(rpc->regmap, RPCIF_SMCR, smcr);
 			ret = wait_msg_xfer_end(rpc);
@@ -521,7 +515,7 @@ int rpcif_manual_xfer(struct rpcif *rpc)
 		}
 		while (pos < rpc->xferlen) {
 			u32 bytes_left = rpc->xferlen - pos;
-			u32 nbytes, data[2];
+			u32 nbytes, data[2], *p = data;
 
 			/* nbytes may only be 1, 2, 4, or 8 */
 			nbytes = bytes_left >= max ? max : (1 << ilog2(bytes_left));
@@ -537,15 +531,9 @@ int rpcif_manual_xfer(struct rpcif *rpc)
 			if (ret)
 				goto err_out;
 
-			if (nbytes == 8) {
-				regmap_read(rpc->regmap, RPCIF_SMRDR1,
-					    &data[0]);
-				regmap_read(rpc->regmap, RPCIF_SMRDR0,
-					    &data[1]);
-			} else {
-				regmap_read(rpc->regmap, RPCIF_SMRDR0,
-					    &data[0]);
-			}
+			if (nbytes == 8)
+				regmap_read(rpc->regmap, RPCIF_SMRDR1, p++);
+			regmap_read(rpc->regmap, RPCIF_SMRDR0, p);
 			memcpy(rpc->buffer + pos, data, nbytes);
 
 			pos += nbytes;