1 files changed, 59 insertions, 0 deletions
diff --git a/drivers/iommu/apple_dart.c b/drivers/iommu/apple_dart.c
new file mode 100644
index 0000000000..ff8c5fa62c
--- /dev/null
+++ b/drivers/iommu/apple_dart.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2021 Mark Kettenis <kettenis@openbsd.org>
+ */
+
+#include <common.h>
+#include <cpu_func.h>
+#include <dm.h>
+#include <asm/io.h>
+
+#define DART_PARAMS2		0x0004
+#define  DART_PARAMS2_BYPASS_SUPPORT	BIT(0)
+#define DART_TLB_OP		0x0020
+#define  DART_TLB_OP_OPMASK	(0xfff << 20)
+#define  DART_TLB_OP_FLUSH	(0x001 << 20)
+#define  DART_TLB_OP_BUSY	BIT(2)
+#define DART_TLB_OP_SIDMASK	0x0034
+#define DART_ERROR_STATUS	0x0040
+#define DART_TCR(sid)		(0x0100 + 4 * (sid))
+#define  DART_TCR_TRANSLATE_ENABLE	BIT(7)
+#define  DART_TCR_BYPASS_DART		BIT(8)
+#define  DART_TCR_BYPASS_DAPF		BIT(12)
+#define DART_TTBR(sid, idx)	(0x0200 + 16 * (sid) + 4 * (idx))
+#define  DART_TTBR_VALID	BIT(31)
+#define  DART_TTBR_SHIFT	12
+
+static int apple_dart_probe(struct udevice *dev)
+{
+	void *base;
+	int sid, i;
+
+	base = dev_read_addr_ptr(dev);
+	if (!base)
+		return -EINVAL;
+
+	u32 params2 = readl(base + DART_PARAMS2);
+	if (params2 & DART_PARAMS2_BYPASS_SUPPORT) {
+		for (sid = 0; sid < 16; sid++) {
+			writel(DART_TCR_BYPASS_DART | DART_TCR_BYPASS_DAPF,
+			       base + DART_TCR(sid));
+			for (i = 0; i < 4; i++)
+				writel(0, base + DART_TTBR(sid, i));
+		}
+	}
+
+	return 0;
+}
+
+static const struct udevice_id apple_dart_ids[] = {
+	{ .compatible = "apple,t8103-dart" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(apple_dart) = {
+	.name = "apple_dart",
+	.id = UCLASS_IOMMU,
+	.of_match = apple_dart_ids,
+	.probe = apple_dart_probe
+};