arm: lib: Add GICV2 driver

Add a generic GICV2 driver that:
- parses the DT and generates the ACPI MADT subtables
- implement of_xlate() and allows irq_get_by_index() to return the
  correct interrupt mappings

Map DT interrupts to ARM GIC interrupts	as follows:

- Interrupt numbers ID32-ID1019 are used for SPIs
- ID0-ID15 are used for SGIs
- ID16-ID31 are used for PPIs

TEST: Booted on QEMU raspb4 using GICV2 driver model generated MADT.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/arm/Kconfig

@@ -113,6 +113,13 @@ config GICV2
 config GICV3
 	bool
 
+config DRIVER_GICV2
+	bool "ARM GICV2 driver"
+	select IRQ
+	help
+	  ARM GICV2 driver.
+	  Basic support for parsing the GICV2 node and generate ACPI tables.
+
 config GIC_V3_ITS
 	bool "ARM GICV3 ITS"
 	select IRQ

arch/arm/lib/Makefile

@@ -68,6 +68,7 @@ obj-$(CONFIG_FSL_LAYERSCAPE) += ccn504.o
 ifneq ($(CONFIG_GICV2)$(CONFIG_GICV3),)
 obj-y	+= gic_64.o
 endif
+obj-$(CONFIG_DRIVER_GICV2)	+= gic-v2.o
 obj-$(CONFIG_GIC_V3_ITS)	+= gic-v3-its.o
 obj-y	+= interrupts_64.o
 else

arch/arm/lib/gic-v2.c

@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2019 Broadcom.
+ */
+#include <dm.h>
+#include <irq.h>
+#include <asm/gic.h>
+#include <asm/acpi_table.h>
+#include <cpu_func.h>
+#include <dm/acpi.h>
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+
+#ifdef CONFIG_ACPIGEN
+/**
+ * acpi_gicv2_fill_madt() - Fill out the body of the MADT
+ *
+ * Write GICD and GICR tables based on collected devicetree data.
+ *
+ * @dev: Device to write ACPI tables for
+ * @ctx: ACPI context to write MADT sub-tables to
+ * Return: 0 if OK
+ */
+static int acpi_gicv2_fill_madt(const struct udevice *dev, struct acpi_ctx *ctx)
+{
+	struct acpi_madt_gicd *gicd;
+	fdt_addr_t addr;
+
+	addr = dev_read_addr_index(dev, 0);
+	if (addr == FDT_ADDR_T_NONE) {
+		pr_err("%s: failed to get GICD address\n", __func__);
+		return -EINVAL;
+	}
+
+	gicd = ctx->current;
+	acpi_write_madt_gicd(gicd, dev_seq(dev), addr, 2);
+	acpi_inc(ctx, gicd->length);
+
+	return 0;
+}
+
+static struct acpi_ops gic_v2_acpi_ops = {
+	.fill_madt	= acpi_gicv2_fill_madt,
+};
+#endif
+
+static const struct udevice_id gic_v2_ids[] = {
+	{ .compatible = "arm,arm11mp-gic" },
+	{ .compatible = "arm,cortex-a15-gic" },
+	{ .compatible = "arm,cortex-a7-gic" },
+	{ .compatible = "arm,cortex-a5-gic" },
+	{ .compatible = "arm,cortex-a9-gic" },
+	{ .compatible = "arm,eb11mp-gic" },
+	{ .compatible = "arm,gic-400" },
+	{ .compatible = "arm,pl390" },
+	{ .compatible = "arm,tc11mp-gic" },
+	{ .compatible = "qcom,msm-8660-qgic" },
+	{ .compatible = "qcom,msm-qgic2" },
+	{}
+};
+
+static int arm_gic_v2_of_xlate(struct irq *irq, struct ofnode_phandle_args *args)
+{
+	if (args->args_count != 3) {
+		log_debug("Invalid args_count: %d\n", args->args_count);
+		return -EINVAL;
+	}
+
+	/* ARM Generic Interrupt Controller v1 and v2 */
+	if (args->args[0] == GIC_SPI)
+		irq->id = args->args[1] + 32;
+	else
+		irq->id = args->args[1] + 16;
+
+	irq->flags = args->args[2];
+
+	return 0;
+}
+
+static const struct irq_ops arm_gic_v2_ops = {
+	.of_xlate		=  arm_gic_v2_of_xlate,
+};
+
+U_BOOT_DRIVER(arm_gic_v2) = {
+	.name		= "gic-v2",
+	.id		= UCLASS_IRQ,
+	.of_match	= gic_v2_ids,
+	.ops		= &arm_gic_v2_ops,
+	ACPI_OPS_PTR(&gic_v2_acpi_ops)
+};