[PATCH v2 4/9] irqchip: irq-renesas-rzg2l: Add support for RZ/G2UL SoC

[Prabhakar <prabhakar.csengg@gmail.com>]

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

The IRQC block on RZ/G2UL SoC is almost identical to one found on the
RZ/G2L SoC the only difference being it can support BUS_ERR_INT for
which it has additional registers.

This patch adds a new entry for "renesas,rzg2ul-irqc" compatible string
and now that we have interrupt-names property the driver code parses the
interrupts based on names and for backward compatibility we fallback to
parse interrupts based on index.

For now we will be using rzg2l_irqc_init() as a callback for RZ/G2UL SoC
too and in future when the interrupt handler will be registered for
BUS_ERR_INT we will have to implement a new callback.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
v1 -> v2
* New patch
---
 drivers/irqchip/irq-renesas-rzg2l.c | 80 ++++++++++++++++++++++++++---
 1 file changed, 74 insertions(+), 6 deletions(-)

diff --git a/drivers/irqchip/irq-renesas-rzg2l.c b/drivers/irqchip/irq-renesas-rzg2l.c
index 7918fe201218..5bdf0106ef51 100644
--- a/drivers/irqchip/irq-renesas-rzg2l.c
+++ b/drivers/irqchip/irq-renesas-rzg2l.c
@@ -299,19 +299,86 @@ static const struct irq_domain_ops rzg2l_irqc_domain_ops = {
 	.translate = irq_domain_translate_twocell,
 };
 
-static int rzg2l_irqc_parse_interrupts(struct rzg2l_irqc_priv *priv,
-				       struct device_node *np)
+static int rzg2l_irqc_parse_interrupt_to_fwspec(struct rzg2l_irqc_priv *priv,
+						struct device_node *np,
+						unsigned int index,
+						unsigned int fwspec_index)
 {
 	struct of_phandle_args map;
+	int ret;
+
+	ret = of_irq_parse_one(np, index, &map);
+	if (ret)
+		return ret;
+
+	of_phandle_args_to_fwspec(np, map.args, map.args_count,
+				  &priv->fwspec[fwspec_index]);
+
+	return 0;
+}
+
+static int rzg2l_irqc_parse_interrupt_by_name_to_fwspec(struct rzg2l_irqc_priv *priv,
+							struct device_node *np,
+							char *irq_name,
+							unsigned int fwspec_index)
+{
+	int index;
+
+	index = of_property_match_string(np, "interrupt-names", irq_name);
+	if (index < 0)
+		return index;
+
+	return rzg2l_irqc_parse_interrupt_to_fwspec(priv, np, index, fwspec_index);
+}
+
+/* Parse hierarchy domain interrupts ie only IRQ0-7 and TINT0-31 */
+static int rzg2l_irqc_parse_hierarchy_interrupts(struct rzg2l_irqc_priv *priv,
+						 struct device_node *np)
+{
+	struct property *pp;
 	unsigned int i;
 	int ret;
 
+	/*
+	 * first check if interrupt-names property exists if so parse them by name
+	 * or else parse them by index for backward compatibility.
+	 */
+	pp = of_find_property(np, "interrupt-names", NULL);
+	if (pp) {
+		char *irq_name;
+
+		/* parse IRQ0-7 */
+		for (i = 0; i < IRQC_IRQ_COUNT; i++) {
+			irq_name = kasprintf(GFP_KERNEL, "irq%d", i);
+			if (!irq_name)
+				return -ENOMEM;
+
+			ret = rzg2l_irqc_parse_interrupt_by_name_to_fwspec(priv, np, irq_name, i);
+			kfree(irq_name);
+			if (ret)
+				return ret;
+		}
+
+		/* parse TINT0-31 */
+		for (i = 0; i < IRQC_TINT_COUNT; i++) {
+			irq_name = kasprintf(GFP_KERNEL, "tint%d", i);
+			if (!irq_name)
+				return -ENOMEM;
+
+			ret = rzg2l_irqc_parse_interrupt_by_name_to_fwspec(priv, np, irq_name,
+									   i + IRQC_IRQ_COUNT);
+			kfree(irq_name);
+			if (ret)
+				return ret;
+		}
+
+		return 0;
+	}
+
 	for (i = 1; i <= IRQC_NUM_HIERARCHY_IRQ; i++) {
-		ret = of_irq_parse_one(np, i, &map);
+		ret = rzg2l_irqc_parse_interrupt_to_fwspec(priv, np, i, i - 1);
 		if (ret)
 			return ret;
-		of_phandle_args_to_fwspec(np, map.args, map.args_count,
-					  &priv->fwspec[i - 1]);
 	}
 
 	return 0;
@@ -343,7 +410,7 @@ static int rzg2l_irqc_init(struct device_node *node, struct device_node *parent)
 	if (IS_ERR(priv->base))
 		return PTR_ERR(priv->base);
 
-	ret = rzg2l_irqc_parse_interrupts(priv, node);
+	ret = rzg2l_irqc_parse_hierarchy_interrupts(priv, node);
 	if (ret) {
 		dev_err(&pdev->dev, "cannot parse interrupts: %d\n", ret);
 		return ret;
@@ -389,6 +456,7 @@ static int rzg2l_irqc_init(struct device_node *node, struct device_node *parent)
 
 IRQCHIP_PLATFORM_DRIVER_BEGIN(rzg2l_irqc)
 IRQCHIP_MATCH("renesas,rzg2l-irqc", rzg2l_irqc_init)
+IRQCHIP_MATCH("renesas,rzg2ul-irqc", rzg2l_irqc_init)
 IRQCHIP_PLATFORM_DRIVER_END(rzg2l_irqc)
 MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>");
 MODULE_DESCRIPTION("Renesas RZ/G2L IRQC Driver");
-- 
2.25.1