1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2020 Sean Anderson
4 */
5
6 #include <common.h>
7 #include <dm.h>
8 #include <regmap.h>
9 #include <reset.h>
10 #include <reset-uclass.h>
11 #include <syscon.h>
12 #include <linux/bitops.h>
13 #include <linux/err.h>
14
15 struct syscon_reset_priv {
16 struct regmap *regmap;
17 uint offset;
18 uint mask;
19 bool assert_high;
20 };
21
syscon_reset_request(struct reset_ctl * rst)22 static int syscon_reset_request(struct reset_ctl *rst)
23 {
24 struct syscon_reset_priv *priv = dev_get_priv(rst->dev);
25
26 if (BIT(rst->id) & priv->mask)
27 return 0;
28 else
29 return -EINVAL;
30 }
31
syscon_reset_assert(struct reset_ctl * rst)32 static int syscon_reset_assert(struct reset_ctl *rst)
33 {
34 struct syscon_reset_priv *priv = dev_get_priv(rst->dev);
35
36 return regmap_update_bits(priv->regmap, priv->offset, BIT(rst->id),
37 priv->assert_high ? BIT(rst->id) : 0);
38 }
39
syscon_reset_deassert(struct reset_ctl * rst)40 static int syscon_reset_deassert(struct reset_ctl *rst)
41 {
42 struct syscon_reset_priv *priv = dev_get_priv(rst->dev);
43
44 return regmap_update_bits(priv->regmap, priv->offset, BIT(rst->id),
45 priv->assert_high ? 0 : BIT(rst->id));
46 }
47
48 static const struct reset_ops syscon_reset_ops = {
49 .request = syscon_reset_request,
50 .rst_assert = syscon_reset_assert,
51 .rst_deassert = syscon_reset_deassert,
52 };
53
syscon_reset_probe(struct udevice * dev)54 int syscon_reset_probe(struct udevice *dev)
55 {
56 struct syscon_reset_priv *priv = dev_get_priv(dev);
57
58 priv->regmap = syscon_regmap_lookup_by_phandle(dev, "regmap");
59 if (IS_ERR(priv->regmap))
60 return -ENODEV;
61
62 priv->offset = dev_read_u32_default(dev, "offset", 0);
63 priv->mask = dev_read_u32_default(dev, "mask", 0);
64 priv->assert_high = dev_read_u32_default(dev, "assert-high", true);
65
66 return 0;
67 }
68
69 static const struct udevice_id syscon_reset_ids[] = {
70 { .compatible = "syscon-reset" },
71 { },
72 };
73
74 U_BOOT_DRIVER(syscon_reset) = {
75 .name = "syscon_reset",
76 .id = UCLASS_RESET,
77 .of_match = syscon_reset_ids,
78 .probe = syscon_reset_probe,
79 .priv_auto = sizeof(struct syscon_reset_priv),
80 .ops = &syscon_reset_ops,
81 };
82