i2c: riic: Pass IRQ desc array as part of OF data

In preparation for adding support for Renesas RZ/T2H and RZ/N2H SoCs,
which feature a combined error interrupt instead of individual error
interrupts per condition, update the driver to support configurable IRQ
layouts via OF data.

Introduce a new `irqs` field and `num_irqs` count in `riic_of_data` to
allow future SoCs to provide a custom IRQ layout. This patch is a
non-functional change for existing SoCs and maintains compatibility with
the current `riic_irqs` array.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com> # on RZ/A1
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20250625104526.101004-4-prabhakar.mahadev-lad.rj@bp.renesas.com

Author: prabhakarlad

drivers/i2c/busses/i2c-riic.c

@@ -102,6 +102,8 @@ enum riic_reg_list {
 
 struct riic_of_data {
 	const u8 *regs;
+	const struct riic_irq_desc *irqs;
+	u8 num_irqs;
 	bool fast_mode_plus;
 };
 
@@ -520,21 +522,23 @@ static int riic_i2c_probe(struct platform_device *pdev)
 		return dev_err_probe(dev, PTR_ERR(riic->rstc),
 				     "failed to acquire deasserted reset\n");
 
-	for (i = 0; i < ARRAY_SIZE(riic_irqs); i++) {
+	riic->info = of_device_get_match_data(dev);
+
+	for (i = 0; i < riic->info->num_irqs; i++) {
+		const struct riic_irq_desc *irq_desc;
 		int irq;
 
-		irq = platform_get_irq(pdev, riic_irqs[i].res_num);
+		irq_desc = &riic->info->irqs[i];
+		irq = platform_get_irq(pdev, irq_desc->res_num);
 		if (irq < 0)
 			return irq;
 
-		ret = devm_request_irq(dev, irq, riic_irqs[i].isr,
-				       0, riic_irqs[i].name, riic);
+		ret = devm_request_irq(dev, irq, irq_desc->isr, 0, irq_desc->name, riic);
 		if (ret)
 			return dev_err_probe(dev, ret, "failed to request irq %s\n",
-					     riic_irqs[i].name);
+					     irq_desc->name);
 	}
 
-	riic->info = of_device_get_match_data(dev);
 
 	adap = &riic->adapter;
 	i2c_set_adapdata(adap, riic);
@@ -606,11 +610,15 @@ static const u8 riic_rz_a_regs[RIIC_REG_END] = {
 
 static const struct riic_of_data riic_rz_a_info = {
 	.regs = riic_rz_a_regs,
+	.irqs = riic_irqs,
+	.num_irqs = ARRAY_SIZE(riic_irqs),
 	.fast_mode_plus = true,
 };
 
 static const struct riic_of_data riic_rz_a1h_info = {
 	.regs = riic_rz_a_regs,
+	.irqs = riic_irqs,
+	.num_irqs = ARRAY_SIZE(riic_irqs),
 };
 
 static const u8 riic_rz_v2h_regs[RIIC_REG_END] = {
@@ -630,6 +638,8 @@ static const u8 riic_rz_v2h_regs[RIIC_REG_END] = {
 
 static const struct riic_of_data riic_rz_v2h_info = {
 	.regs = riic_rz_v2h_regs,
+	.irqs = riic_irqs,
+	.num_irqs = ARRAY_SIZE(riic_irqs),
 	.fast_mode_plus = true,
 };