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