[RFC PATCH v1 15/21] ACPI: RISC-V: Create IMSIC platform device

[Sunil V L <sunilvl@xxxxxxxxxxxxxxxx>]

The MSI controller functionality of the RISC-V IMSIC is
probed as a platform device by the driver. So, create the
IMSIC platform device if the IMSIC was discovered in MADT
during early IMSIC driver probe.

Signed-off-by: Sunil V L <sunilvl@xxxxxxxxxxxxxxxx>
---
 drivers/acpi/riscv/init.c    |  2 ++
 drivers/acpi/riscv/init.h    |  4 ++++
 drivers/acpi/riscv/irqchip.c | 23 +++++++++++++++++++++++
 3 files changed, 29 insertions(+)
 create mode 100644 drivers/acpi/riscv/init.h

diff --git a/drivers/acpi/riscv/init.c b/drivers/acpi/riscv/init.c
index b5807bbdb171..be61c08ea385 100644
--- a/drivers/acpi/riscv/init.c
+++ b/drivers/acpi/riscv/init.c
@@ -6,7 +6,9 @@
  */
 
 #include <linux/acpi.h>
+#include "init.h"
 
 void __init acpi_riscv_init(void)
 {
+	riscv_acpi_imsic_platform_init();
 }
diff --git a/drivers/acpi/riscv/init.h b/drivers/acpi/riscv/init.h
new file mode 100644
index 000000000000..a2f72bb294d3
--- /dev/null
+++ b/drivers/acpi/riscv/init.h
@@ -0,0 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#include <linux/init.h>
+
+void __init riscv_acpi_imsic_platform_init(void);
diff --git a/drivers/acpi/riscv/irqchip.c b/drivers/acpi/riscv/irqchip.c
index 6e15d45cb229..ca96bf109cf7 100644
--- a/drivers/acpi/riscv/irqchip.c
+++ b/drivers/acpi/riscv/irqchip.c
@@ -9,7 +9,10 @@
 #include <linux/fwnode.h>
 #include <linux/irqdomain.h>
 #include <linux/list.h>
+#include <linux/msi.h>
+#include <linux/platform_device.h>
 #include <linux/property.h>
+#include "../../../drivers/pci/pci.h"
 
 struct riscv_irqchip_list {
 	struct fwnode_handle *fwnode;
@@ -101,3 +104,23 @@ struct fwnode_handle *acpi_riscv_get_msi_fwnode(struct device *dev)
 {
 	return imsic_acpi_fwnode;
 }
+
+void __init riscv_acpi_imsic_platform_init(void)
+{
+	struct platform_device *pdev;
+	int ret;
+
+	if (!acpi_riscv_get_msi_fwnode(NULL)) {
+		pci_no_msi();
+		return;
+	}
+
+	pdev = platform_device_alloc("riscv-imsic", 0);
+	if (!pdev)
+		return;
+
+	pdev->dev.fwnode = acpi_riscv_get_msi_fwnode(NULL);
+	ret = platform_device_add(pdev);
+	if (ret)
+		platform_device_put(pdev);
+}
-- 
2.39.2