1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2021 Mark Kettenis <kettenis@openbsd.org>
4 */
5
6 #include <common.h>
7 #include <cpu_func.h>
8 #include <dm.h>
9 #include <asm/io.h>
10
11 #define DART_PARAMS2 0x0004
12 #define DART_PARAMS2_BYPASS_SUPPORT BIT(0)
13 #define DART_TLB_OP 0x0020
14 #define DART_TLB_OP_OPMASK (0xfff << 20)
15 #define DART_TLB_OP_FLUSH (0x001 << 20)
16 #define DART_TLB_OP_BUSY BIT(2)
17 #define DART_TLB_OP_SIDMASK 0x0034
18 #define DART_ERROR_STATUS 0x0040
19 #define DART_TCR(sid) (0x0100 + 4 * (sid))
20 #define DART_TCR_TRANSLATE_ENABLE BIT(7)
21 #define DART_TCR_BYPASS_DART BIT(8)
22 #define DART_TCR_BYPASS_DAPF BIT(12)
23 #define DART_TTBR(sid, idx) (0x0200 + 16 * (sid) + 4 * (idx))
24 #define DART_TTBR_VALID BIT(31)
25 #define DART_TTBR_SHIFT 12
26
apple_dart_probe(struct udevice * dev)27 static int apple_dart_probe(struct udevice *dev)
28 {
29 void *base;
30 int sid, i;
31
32 base = dev_read_addr_ptr(dev);
33 if (!base)
34 return -EINVAL;
35
36 u32 params2 = readl(base + DART_PARAMS2);
37 if (params2 & DART_PARAMS2_BYPASS_SUPPORT) {
38 for (sid = 0; sid < 16; sid++) {
39 writel(DART_TCR_BYPASS_DART | DART_TCR_BYPASS_DAPF,
40 base + DART_TCR(sid));
41 for (i = 0; i < 4; i++)
42 writel(0, base + DART_TTBR(sid, i));
43 }
44 }
45
46 return 0;
47 }
48
49 static const struct udevice_id apple_dart_ids[] = {
50 { .compatible = "apple,t8103-dart" },
51 { /* sentinel */ }
52 };
53
54 U_BOOT_DRIVER(apple_dart) = {
55 .name = "apple_dart",
56 .id = UCLASS_IOMMU,
57 .of_match = apple_dart_ids,
58 .probe = apple_dart_probe
59 };
60