lib: utils/irqchip: Allow multiple FDT irqchip drivers

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>

diff --git a/lib/utils/irqchip/fdt_irqchip.c b/lib/utils/irqchip/fdt_irqchip.c
index 8dda661..bf6969a 100644 (file)
--- 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;
        }