[PATCH v3 21/23] irqchip/riscv-rpmi-sysmsi: Add ACPI support

[Anup Patel <apatel@ventanamicro.com>]

From: Sunil V L <sunilvl@ventanamicro.com>

Add ACPI support for the RISC-V RPMI system MSI based irqchip driver.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/Kconfig                 |  2 +-
 drivers/irqchip/irq-riscv-rpmi-sysmsi.c | 41 +++++++++++++++++++++++--
 2 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 83700fc2ddc9..132e56a596fc 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -614,7 +614,7 @@ config RISCV_IMSIC
 
 config RISCV_RPMI_SYSMSI
 	bool
-	depends on MAILBOX
+	depends on RISCV && MAILBOX
 	select IRQ_DOMAIN_HIERARCHY
 	select GENERIC_MSI_IRQ
 	default RISCV
diff --git a/drivers/irqchip/irq-riscv-rpmi-sysmsi.c b/drivers/irqchip/irq-riscv-rpmi-sysmsi.c
index 9f14a92290c4..cfe8d45dba97 100644
--- a/drivers/irqchip/irq-riscv-rpmi-sysmsi.c
+++ b/drivers/irqchip/irq-riscv-rpmi-sysmsi.c
@@ -3,11 +3,13 @@
  * Copyright (C) 2025 Ventana Micro Systems Inc.
  */
 
+#include <linux/acpi.h>
 #include <linux/bitfield.h>
 #include <linux/bitops.h>
 #include <linux/cpu.h>
 #include <linux/interrupt.h>
 #include <linux/irqchip.h>
+#include <linux/irqchip/riscv-imsic.h>
 #include <linux/mailbox_client.h>
 #include <linux/mailbox/riscv-rpmi-message.h>
 #include <linux/module.h>
@@ -212,6 +214,8 @@ static int rpmi_sysmsi_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct rpmi_sysmsi_priv *priv;
+	struct irq_domain *msi_domain;
+	u32 id;
 	int rc;
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
@@ -240,6 +244,21 @@ static int rpmi_sysmsi_probe(struct platform_device *pdev)
 	}
 	priv->nr_irqs = rc;
 
+	if (is_acpi_node(dev_fwnode(dev))) {
+		u32 nr_irqs;
+
+		rc = riscv_acpi_get_gsi_info(dev_fwnode(dev), &priv->gsi_base, &id,
+					     &nr_irqs, NULL);
+		if (rc) {
+			dev_err(dev, "failed to find GSI mapping\n");
+			return rc;
+		}
+
+		/* Update with actual GSI range */
+		if (nr_irqs != priv->nr_irqs)
+			riscv_acpi_update_gsi_range(priv->gsi_base, priv->nr_irqs);
+	}
+
 	/* Set the device MSI domain if not available */
 	if (!dev_get_msi_domain(dev)) {
 		/*
@@ -249,8 +268,13 @@ static int rpmi_sysmsi_probe(struct platform_device *pdev)
 		 * then we need to set it explicitly before using any platform
 		 * MSI functions.
 		 */
-		if (is_of_node(dev_fwnode(dev)))
+		if (is_of_node(dev_fwnode(dev))) {
 			of_msi_configure(dev, to_of_node(dev_fwnode(dev)));
+		} else {
+			msi_domain = irq_find_matching_fwnode(imsic_acpi_get_fwnode(dev),
+							      DOMAIN_BUS_PLATFORM_MSI);
+			dev_set_msi_domain(dev, msi_domain);
+		}
 
 		if (!dev_get_msi_domain(dev))
 			return -EPROBE_DEFER;
@@ -261,6 +285,10 @@ static int rpmi_sysmsi_probe(struct platform_device *pdev)
 					  priv->nr_irqs, priv, priv))
 		return dev_err_probe(dev, -ENOMEM, "failed to create MSI irq domain\n");
 
+#ifdef CONFIG_ACPI
+	if (!acpi_disabled)
+		acpi_dev_clear_dependencies(ACPI_COMPANION(dev));
+#endif
 	dev_info(dev, "%d system MSIs registered\n", priv->nr_irqs);
 	return 0;
 }
@@ -270,10 +298,17 @@ static const struct of_device_id rpmi_sysmsi_match[] = {
 	{}
 };
 
+static const struct acpi_device_id acpi_rpmi_sysmsi_match[] = {
+	{ "RSCV0006" },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, acpi_rpmi_sysmsi_match);
+
 static struct platform_driver rpmi_sysmsi_driver = {
 	.driver = {
-		.name		= "rpmi-sysmsi",
-		.of_match_table	= rpmi_sysmsi_match,
+		.name			= "rpmi-sysmsi",
+		.of_match_table		= rpmi_sysmsi_match,
+		.acpi_match_table	= acpi_rpmi_sysmsi_match,
 	},
 	.probe = rpmi_sysmsi_probe,
 };
-- 
2.43.0