[PATCH v2 05/13] lib: utils/irqchip: Allow multiple FDT irqchip drivers

[Anup Patel <apatel@ventanamicro.com>]

We can have multiple FDT irqchip drivers to be probed when a RISC-V
system has different types of interrupt controller in a hierarchy.

This will be certainly the case when a RISC-V system has both
RISC-V AIA IMSIC and RISC-V AIA APLIC implemented.

We extend simple FDT irqchip framework to allow multiple FDT
irqchip drivers to be used for same RISC-V platform.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
---
 lib/utils/irqchip/fdt_irqchip.c | 37 ++++++++++++++++++++++++++-------
 1 file changed, 30 insertions(+), 7 deletions(-)

diff --git a/lib/utils/irqchip/fdt_irqchip.c b/lib/utils/irqchip/fdt_irqchip.c
index 8dda661..bf6969a 100644
--- a/lib/utils/irqchip/fdt_irqchip.c
+++ b/lib/utils/irqchip/fdt_irqchip.c
@@ -18,23 +18,40 @@ static struct fdt_irqchip *irqchip_drivers[] = {
 	&fdt_irqchip_plic
 };
 
-static struct fdt_irqchip *current_driver = NULL;
+#define FDT_IRQCHIP_MAX_DRIVERS	8
+
+static struct fdt_irqchip *current_drivers[FDT_IRQCHIP_MAX_DRIVERS] = {0};
+static int current_drivers_count;
 
 void fdt_irqchip_exit(void)
 {
-	if (current_driver && current_driver->exit)
-		current_driver->exit();
+	int i;
+
+	for (i = 0; i < current_drivers_count; i++) {
+		if (!current_drivers[i] || !current_drivers[i]->exit)
+			continue;
+		current_drivers[i]->exit();
+	}
 }
 
 static int fdt_irqchip_warm_init(void)
 {
-	if (current_driver && current_driver->warm_init)
-		return current_driver->warm_init();
+	int i, rc;
+
+	for (i = 0; i < current_drivers_count; i++) {
+		if (!current_drivers[i] || !current_drivers[i]->warm_init)
+			continue;
+		rc = current_drivers[i]->warm_init();
+		if (rc)
+			return rc;
+	}
+
 	return 0;
 }
 
 static int fdt_irqchip_cold_init(void)
 {
+	bool drv_added;
 	int pos, noff, rc;
 	struct fdt_irqchip *drv;
 	const struct fdt_match *match;
@@ -44,6 +61,7 @@ static int fdt_irqchip_cold_init(void)
 		drv = irqchip_drivers[pos];
 
 		noff = -1;
+		drv_added = false;
 		while ((noff = fdt_find_match(fdt, noff,
 					drv->match_table, &match)) >= 0) {
 			if (drv->cold_init) {
@@ -53,10 +71,15 @@ static int fdt_irqchip_cold_init(void)
 				if (rc)
 					return rc;
 			}
-			current_driver = drv;
+
+			if (drv_added)
+				continue;
+
+			current_drivers[current_drivers_count++] = drv;
+			drv_added = true;
 		}
 
-		if (current_driver)
+		if (FDT_IRQCHIP_MAX_DRIVERS <= current_drivers_count)
 			break;
 	}
 
-- 
2.25.1