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 <dm.h>
10 #include <log.h>
11 #include <malloc.h>
12 #include <dm/lists.h>
13 #include <regmap.h>
14 #include <reset-uclass.h>
15 #include <syscon.h>
16 #include <dm/device-internal.h>
17 #include <linux/bitops.h>
18 #include <linux/err.h>
19
20 struct mediatek_reset_priv {
21 struct regmap *regmap;
22 u32 regofs;
23 u32 nr_resets;
24 };
25
mediatek_reset_assert(struct reset_ctl * reset_ctl)26 static int mediatek_reset_assert(struct reset_ctl *reset_ctl)
27 {
28 struct mediatek_reset_priv *priv = dev_get_priv(reset_ctl->dev);
29 int id = reset_ctl->id;
30
31 if (id >= priv->nr_resets)
32 return -EINVAL;
33
34 return regmap_update_bits(priv->regmap,
35 priv->regofs + ((id / 32) << 2), BIT(id % 32), BIT(id % 32));
36 }
37
mediatek_reset_deassert(struct reset_ctl * reset_ctl)38 static int mediatek_reset_deassert(struct reset_ctl *reset_ctl)
39 {
40 struct mediatek_reset_priv *priv = dev_get_priv(reset_ctl->dev);
41 int id = reset_ctl->id;
42
43 if (id >= priv->nr_resets)
44 return -EINVAL;
45
46 return regmap_update_bits(priv->regmap,
47 priv->regofs + ((id / 32) << 2), BIT(id % 32), 0);
48 }
49
50 struct reset_ops mediatek_reset_ops = {
51 .rst_assert = mediatek_reset_assert,
52 .rst_deassert = mediatek_reset_deassert,
53 };
54
mediatek_reset_probe(struct udevice * dev)55 static int mediatek_reset_probe(struct udevice *dev)
56 {
57 struct mediatek_reset_priv *priv = dev_get_priv(dev);
58
59 if (!priv->regofs && !priv->nr_resets)
60 return -EINVAL;
61
62 priv->regmap = syscon_node_to_regmap(dev_ofnode(dev));
63 if (IS_ERR(priv->regmap))
64 return PTR_ERR(priv->regmap);
65
66 return 0;
67 }
68
mediatek_reset_bind(struct udevice * pdev,u32 regofs,u32 num_regs)69 int mediatek_reset_bind(struct udevice *pdev, u32 regofs, u32 num_regs)
70 {
71 struct udevice *rst_dev;
72 struct mediatek_reset_priv *priv;
73 int ret;
74
75 ret = device_bind_driver_to_node(pdev, "mediatek_reset", "reset",
76 dev_ofnode(pdev), &rst_dev);
77 if (ret)
78 return ret;
79
80 priv = malloc(sizeof(struct mediatek_reset_priv));
81 if (!priv)
82 return -ENOMEM;
83
84 priv->regofs = regofs;
85 priv->nr_resets = num_regs * 32;
86 dev_set_priv(rst_dev, priv);
87
88 return 0;
89 }
90
91 U_BOOT_DRIVER(mediatek_reset) = {
92 .name = "mediatek_reset",
93 .id = UCLASS_RESET,
94 .probe = mediatek_reset_probe,
95 .ops = &mediatek_reset_ops,
96 .priv_auto = sizeof(struct mediatek_reset_priv),
97 };
98