memory: renesas-rpc-if: Add support for R-Car Gen4

The SPI Multi I/O Bus Controller (RPC-IF) on R-Car Gen4 SoCs is very
similar to the RPC-IF on R-Car Gen3 SoCs.  It does support four instead
of three bits of strobe timing adjustment (STRTIM), and thus requires a
new mask and new settings.

Inspired by a patch in the BSP by Cong Dang.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/4d0824bf5ed0fb95c51cd36f9a3f0f562b1a6bf8.1665583089.git.geert+renesas@glider.beSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

drivers/memory/renesas-rpc-if.c

@@ -136,7 +136,8 @@
 #define RPCIF_PHYCNT_DDRCAL	BIT(19)
 #define RPCIF_PHYCNT_HS		BIT(18)
 #define RPCIF_PHYCNT_CKSEL(v)	(((v) & 0x3) << 16) /* valid only for RZ/G2L */
-#define RPCIF_PHYCNT_STRTIM(v)	(((v) & 0x7) << 15) /* valid for R-Car and RZ/G2{E,H,M,N} */
+#define RPCIF_PHYCNT_STRTIM(v)	(((v) & 0x7) << 15 | ((v) & 0x8) << 24) /* valid for R-Car and RZ/G2{E,H,M,N} */
+
 #define RPCIF_PHYCNT_WBUF2	BIT(4)
 #define RPCIF_PHYCNT_WBUF	BIT(2)
 #define RPCIF_PHYCNT_PHYMEM(v)	(((v) & 0x3) << 0)
@@ -323,6 +324,9 @@ int rpcif_hw_init(struct rpcif *rpc, bool hyperflash)
 	if (rpc->type == RPCIF_RCAR_GEN3)
 		regmap_update_bits(rpc->regmap, RPCIF_PHYCNT,
 				   RPCIF_PHYCNT_STRTIM(7), RPCIF_PHYCNT_STRTIM(7));
+	else if (rpc->type == RPCIF_RCAR_GEN4)
+		regmap_update_bits(rpc->regmap, RPCIF_PHYCNT,
+				   RPCIF_PHYCNT_STRTIM(15), RPCIF_PHYCNT_STRTIM(15));
 
 	regmap_update_bits(rpc->regmap, RPCIF_PHYOFFSET1, RPCIF_PHYOFFSET1_DDRTMG(3),
 			   RPCIF_PHYOFFSET1_DDRTMG(3));
@@ -333,17 +337,17 @@ int rpcif_hw_init(struct rpcif *rpc, bool hyperflash)
 		regmap_update_bits(rpc->regmap, RPCIF_PHYINT,
 				   RPCIF_PHYINT_WPVAL, 0);
 
-	if (rpc->type == RPCIF_RCAR_GEN3)
-		regmap_update_bits(rpc->regmap, RPCIF_CMNCR,
-				   RPCIF_CMNCR_MOIIO(3) | RPCIF_CMNCR_BSZ(3),
-				   RPCIF_CMNCR_MOIIO(3) |
-				   RPCIF_CMNCR_BSZ(hyperflash ? 1 : 0));
-	else
+	if (rpc->type == RPCIF_RZ_G2L)
 		regmap_update_bits(rpc->regmap, RPCIF_CMNCR,
 				   RPCIF_CMNCR_MOIIO(3) | RPCIF_CMNCR_IOFV(3) |
 				   RPCIF_CMNCR_BSZ(3),
 				   RPCIF_CMNCR_MOIIO(1) | RPCIF_CMNCR_IOFV(2) |
 				   RPCIF_CMNCR_BSZ(hyperflash ? 1 : 0));
+	else
+		regmap_update_bits(rpc->regmap, RPCIF_CMNCR,
+				   RPCIF_CMNCR_MOIIO(3) | RPCIF_CMNCR_BSZ(3),
+				   RPCIF_CMNCR_MOIIO(3) |
+				   RPCIF_CMNCR_BSZ(hyperflash ? 1 : 0));
 
 	/* Set RCF after BSZ update */
 	regmap_write(rpc->regmap, RPCIF_DRCR, RPCIF_DRCR_RCF);
@@ -718,6 +722,7 @@ static int rpcif_remove(struct platform_device *pdev)
 
 static const struct of_device_id rpcif_of_match[] = {
 	{ .compatible = "renesas,rcar-gen3-rpc-if", .data = (void *)RPCIF_RCAR_GEN3 },
+	{ .compatible = "renesas,rcar-gen4-rpc-if", .data = (void *)RPCIF_RCAR_GEN4 },
 	{ .compatible = "renesas,rzg2l-rpc-if", .data = (void *)RPCIF_RZ_G2L },
 	{},
 };

include/memory/renesas-rpc-if.h

@@ -59,6 +59,7 @@ struct rpcif_op {
 
 enum rpcif_type {
 	RPCIF_RCAR_GEN3,
+	RPCIF_RCAR_GEN4,
 	RPCIF_RZ_G2L,
 };