generic: rtl8366rb: add support for initvals from DTS

Allow per-device initvals in the DTS file for rlt8366rb
switches.

Shamelessly copies 30494598f8

Signed-off-by: Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>

target/linux/generic/files/drivers/net/phy/rtl8366rb.c

@@ -282,6 +282,31 @@ static int rtl8366rb_reset_chip(struct rtl8366_smi *smi)
 static int rtl8366rb_setup(struct rtl8366_smi *smi)
 {
 	int err;
+#ifdef CONFIG_OF
+	unsigned i;
+	struct device_node *np;
+	unsigned num_initvals;
+	const __be32 *paddr;
+
+	np = smi->parent->of_node;
+
+	paddr = of_get_property(np, "realtek,initvals", &num_initvals);
+	if (paddr) {
+		dev_info(smi->parent, "applying initvals from DTS\n");
+
+		if (num_initvals < (2 * sizeof(*paddr)))
+			return -EINVAL;
+
+		num_initvals /= sizeof(*paddr);
+
+		for (i = 0; i < num_initvals - 1; i += 2) {
+			u32 reg = be32_to_cpup(paddr + i);
+			u32 val = be32_to_cpup(paddr + i + 1);
+
+			REG_WR(smi, reg, val);
+		}
+	}
+#endif
 
 	/* set maximum packet length to 1536 bytes */
 	REG_RMW(smi, RTL8366RB_SGCR, RTL8366RB_SGCR_MAX_LENGTH_MASK,