[PATCH] lib: utils/irqchip: Automatically delegate T-HEAD PLIC access

[Samuel Holland]

The T-HEAD PLIC implementation requires setting a delegation bit
to allow access from S-mode. For the D1 SoC, let's set this bit
automatically from the PLIC driver, instead of relying on another
driver reaching into the PLIC's MMIO space.

Signed-off-by: Samuel Holland <samuel at sholland.org>
---
 docs/platform/thead-c9xx.md          |  8 ++------
 lib/utils/irqchip/fdt_irqchip_plic.c | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/docs/platform/thead-c9xx.md b/docs/platform/thead-c9xx.md
index c0daeb7..125edf4 100644
--- a/docs/platform/thead-c9xx.md
+++ b/docs/platform/thead-c9xx.md
@@ -51,11 +51,6 @@ DTS Example1: (Single core, eg: Allwinner D1 - c906)
 		compatible = "simple-bus";
 		ranges;
 
-		reset: reset-sample {
-			compatible = "thead,reset-sample";
-			plic-delegate = <0x0 0x101ffffc>;
-		};
-
 		clint0: clint at 14000000 {
 			compatible = "riscv,clint0";
 			interrupts-extended = <
@@ -67,7 +62,8 @@ DTS Example1: (Single core, eg: Allwinner D1 - c906)
 
 		intc: interrupt-controller at 10000000 {
 			#interrupt-cells = <1>;
-			compatible = "riscv,plic0";
+			compatible = "allwinner,sun20i-d1-plic",
+				     "riscv,plic0";
 			interrupt-controller;
 			interrupts-extended = <
 				&cpu0_intc  0xffffffff &cpu0_intc  9
diff --git a/lib/utils/irqchip/fdt_irqchip_plic.c b/lib/utils/irqchip/fdt_irqchip_plic.c
index 18d2797..b044b28 100644
--- a/lib/utils/irqchip/fdt_irqchip_plic.c
+++ b/lib/utils/irqchip/fdt_irqchip_plic.c
@@ -9,6 +9,7 @@
 
 #include <libfdt.h>
 #include <sbi/riscv_asm.h>
+#include <sbi/riscv_io.h>
 #include <sbi/sbi_error.h>
 #include <sbi/sbi_hartmask.h>
 #include <sbi_utils/fdt/fdt_helper.h>
@@ -91,6 +92,13 @@ static int irqchip_plic_cold_init(void *fdt, int nodeoff,
 	if (rc)
 		return rc;
 
+	if (match->data) {
+		int (*plic_plat_init)(struct plic_data *) = match->data;
+		rc = plic_plat_init(pd);
+		if (rc)
+			return rc;
+	}
+
 	rc = plic_cold_irqchip_init(pd);
 	if (rc)
 		return rc;
@@ -106,7 +114,18 @@ static int irqchip_plic_cold_init(void *fdt, int nodeoff,
 	return irqchip_plic_update_hartid_table(fdt, nodeoff, pd);
 }
 
+#define THEAD_PLIC_CTRL_REG 0x1ffffc
+
+static int thead_plic_plat_init(struct plic_data *pd)
+{
+	writel_relaxed(BIT(0), (void *)pd->addr + THEAD_PLIC_CTRL_REG);
+
+	return 0;
+}
+
 static const struct fdt_match irqchip_plic_match[] = {
+	{ .compatible = "allwinner,sun20i-d1-plic",
+	  .data = thead_plic_plat_init },
 	{ .compatible = "riscv,plic0" },
 	{ .compatible = "sifive,plic-1.0.0" },
 	{ },
-- 
2.31.1