irqchip/renesas-rza1: Use for_each_of_imap_item iterator

The renesas-rza1 driver parses the interrupt-map property. It does it
using open code.

Recently for_each_of_imap_item iterator has been introduce to help
drivers in this parsing.

Convert the renesas-rza1 driver to use the for_each_of_imap_item
iterator instead of open code.

Signed-off-by: Herve Codina (Schneider Electric) <[e-mail]>
Tested-by: Wolfram Sang <[e-mail]>
Reviewed-by: Linus Walleij <[e-mail]>
Reviewed-by: Thomas Gleixner <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Geert Uytterhoeven <[e-mail]>

drivers/irqchip/irq-renesas-rza1.c

···
 static int rza1_irqc_parse_map(struct rza1_irqc_priv *priv,
 			       struct device_node *gic_node)
 {
+	struct of_imap_parser imap_parser;
 	struct device *dev = priv->dev;
-	unsigned int imaplen, i, j;
+	struct of_imap_item imap_item;
 	struct device_node *ipar;
-	const __be32 *imap;
-	u32 intsize;
+	unsigned int j;
+	u32 i = 0;
 	int ret;
 
-	imap = of_get_property(dev->of_node, "interrupt-map", &imaplen);
-	if (!imap)
-		return -EINVAL;
+	ret = of_imap_parser_init(&imap_parser, dev->of_node, &imap_item);
+	if (ret)
+		return ret;
 
-	for (i = 0; i < IRQC_NUM_IRQ; i++) {
-		if (imaplen < 3)
-			return -EINVAL;
-
+	for_each_of_imap_item(&imap_parser, &imap_item) {
 		/* Check interrupt number, ignore sense */
-		if (be32_to_cpup(imap) != i)
+		if (imap_item.child_imap[0] != i) {
+			of_node_put(imap_item.parent_args.np);
 			return -EINVAL;
+		}
 
-		ipar = of_find_node_by_phandle(be32_to_cpup(imap + 2));
+		ipar  = imap_item.parent_args.np;
 		if (ipar != gic_node) {
 			of_node_put(ipar);
 			return -EINVAL;
 		}
 
-		imap += 3;
-		imaplen -= 3;
+		priv->map[i].args_count = imap_item.parent_args.args_count;
+		for (j = 0; j < priv->map[i].args_count; j++)
+			priv->map[i].args[j] = imap_item.parent_args.args[j];
 
-		ret = of_property_read_u32(ipar, "#interrupt-cells", &intsize);
-		of_node_put(ipar);
-		if (ret)
-			return ret;
-
-		if (imaplen < intsize)
-			return -EINVAL;
-
-		priv->map[i].args_count = intsize;
-		for (j = 0; j < intsize; j++)
-			priv->map[i].args[j] = be32_to_cpup(imap++);
-
-		imaplen -= intsize;
+		i++;
 	}
 
 	return 0;