1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2018 MediaTek Inc.
4  *
5  * Author: Ryder Lee <ryder.lee@mediatek.com>
6  *	   Weijie Gao <weijie.gao@mediatek.com>
7  */
8 
9 #include <common.h>
10 #include <dm.h>
11 #include <dm/lists.h>
12 #include <regmap.h>
13 #include <reset-uclass.h>
14 #include <syscon.h>
15 
16 struct mediatek_reset_priv {
17 	struct regmap *regmap;
18 	u32 regofs;
19 	u32 nr_resets;
20 };
21 
22 static int mediatek_reset_request(struct reset_ctl *reset_ctl)
23 {
24 	return 0;
25 }
26 
27 static int mediatek_reset_free(struct reset_ctl *reset_ctl)
28 {
29 	return 0;
30 }
31 
32 static int mediatek_reset_assert(struct reset_ctl *reset_ctl)
33 {
34 	struct mediatek_reset_priv *priv = dev_get_priv(reset_ctl->dev);
35 	int id = reset_ctl->id;
36 
37 	if (id >= priv->nr_resets)
38 		return -EINVAL;
39 
40 	return regmap_update_bits(priv->regmap,
41 		priv->regofs + ((id / 32) << 2), BIT(id % 32), BIT(id % 32));
42 }
43 
44 static int mediatek_reset_deassert(struct reset_ctl *reset_ctl)
45 {
46 	struct mediatek_reset_priv *priv = dev_get_priv(reset_ctl->dev);
47 	int id = reset_ctl->id;
48 
49 	if (id >= priv->nr_resets)
50 		return -EINVAL;
51 
52 	return regmap_update_bits(priv->regmap,
53 		priv->regofs + ((id / 32) << 2), BIT(id % 32), 0);
54 }
55 
56 struct reset_ops mediatek_reset_ops = {
57 	.request = mediatek_reset_request,
58 	.free = mediatek_reset_free,
59 	.rst_assert = mediatek_reset_assert,
60 	.rst_deassert = mediatek_reset_deassert,
61 };
62 
63 static int mediatek_reset_probe(struct udevice *dev)
64 {
65 	struct mediatek_reset_priv *priv = dev_get_priv(dev);
66 
67 	if (!priv->regofs && !priv->nr_resets)
68 		return -EINVAL;
69 
70 	priv->regmap = syscon_node_to_regmap(dev_ofnode(dev));
71 	if (IS_ERR(priv->regmap))
72 		return PTR_ERR(priv->regmap);
73 
74 	return 0;
75 }
76 
77 int mediatek_reset_bind(struct udevice *pdev, u32 regofs, u32 num_regs)
78 {
79 	struct udevice *rst_dev;
80 	struct mediatek_reset_priv *priv;
81 	int ret;
82 
83 	ret = device_bind_driver_to_node(pdev, "mediatek_reset", "reset",
84 					 dev_ofnode(pdev), &rst_dev);
85 	if (ret)
86 		return ret;
87 
88 	priv = malloc(sizeof(struct mediatek_reset_priv));
89 	priv->regofs = regofs;
90 	priv->nr_resets = num_regs * 32;
91 	rst_dev->priv = priv;
92 
93 	return 0;
94 }
95 
96 U_BOOT_DRIVER(mediatek_reset) = {
97 	.name = "mediatek_reset",
98 	.id = UCLASS_RESET,
99 	.probe = mediatek_reset_probe,
100 	.ops = &mediatek_reset_ops,
101 	.priv_auto_alloc_size = sizeof(struct mediatek_reset_priv),
102 };
103