soc: renesas: Add support to read LSI DEVID register of RZ/G2{L,LC} SoC's

Add support for reading the LSI DEVID register which is present in
SYSC block of RZ/G2{L,LC} SoC's.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20210609163717.3083-3-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

drivers/soc/renesas/renesas-soc.c

@@ -56,6 +56,10 @@ static const struct renesas_family fam_rzg2 __initconst __maybe_unused = {
 	.reg	= 0xfff00044,		/* PRR (Product Register) */
 };
 
+static const struct renesas_family fam_rzg2l __initconst __maybe_unused = {
+	.name	= "RZ/G2L",
+};
+
 static const struct renesas_family fam_shmobile __initconst __maybe_unused = {
 	.name	= "SH-Mobile",
 	.reg	= 0xe600101c,		/* CCCR (Common Chip Code Register) */
@@ -64,7 +68,7 @@ static const struct renesas_family fam_shmobile __initconst __maybe_unused = {
 
 struct renesas_soc {
 	const struct renesas_family *family;
-	u8 id;
+	u32 id;
 };
 
 static const struct renesas_soc soc_rz_a1h __initconst __maybe_unused = {
@@ -131,6 +135,11 @@ static const struct renesas_soc soc_rz_g2h __initconst __maybe_unused = {
 	.id	= 0x4f,
 };
 
+static const struct renesas_soc soc_rz_g2l __initconst __maybe_unused = {
+	.family = &fam_rzg2l,
+	.id     = 0x841c447,
+};
+
 static const struct renesas_soc soc_rcar_m1a __initconst __maybe_unused = {
 	.family	= &fam_rcar_gen1,
 };
@@ -299,6 +308,9 @@ static const struct of_device_id renesas_socs[] __initconst = {
 #ifdef CONFIG_ARCH_R8A779A0
 	{ .compatible = "renesas,r8a779a0",	.data = &soc_rcar_v3u },
 #endif
+#if defined(CONFIG_ARCH_R9A07G044)
+	{ .compatible = "renesas,r9a07g044",	.data = &soc_rz_g2l },
+#endif
 #ifdef CONFIG_ARCH_SH73A0
 	{ .compatible = "renesas,sh73a0",	.data = &soc_shmobile_ag5 },
 #endif
@@ -348,6 +360,25 @@ static int __init renesas_soc_init(void)
 		goto done;
 	}
 
+	np = of_find_compatible_node(NULL, NULL, "renesas,r9a07g044-sysc");
+	if (np) {
+		chipid = of_iomap(np, 0);
+		of_node_put(np);
+
+		if (chipid) {
+			product = readl(chipid + 0x0a04);
+			iounmap(chipid);
+
+			if (soc->id && (product & 0xfffffff) != soc->id) {
+				pr_warn("SoC mismatch (product = 0x%x)\n",
+					product);
+				return -ENODEV;
+			}
+		}
+
+		goto done;
+	}
+
 	/* Try PRR first, then hardcoded fallback */
 	np = of_find_compatible_node(NULL, NULL, "renesas,prr");
 	if (np) {