1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Texas Instruments DRA7 reset driver
4 *
5 * Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com/
6 * Author: Keerthy <j-keerthy@ti.com>
7 */
8
9#include <asm/io.h>
10#include <common.h>
11#include <dm.h>
12#include <reset-uclass.h>
13#include <dm/device_compat.h>
14
15struct dra7_reset_priv {
16	u32 rstctrl;
17	u32 rstst;
18	u8 nreset;
19};
20
21static inline void dra7_reset_rmw(u32 addr, u32 value, u32 mask)
22{
23	writel(((readl(addr) & (~mask)) | (value & mask)), addr);
24}
25
26static int dra7_reset_deassert(struct reset_ctl *reset_ctl)
27{
28	struct dra7_reset_priv *priv = dev_get_priv(reset_ctl->dev);
29	int mask = 1 << reset_ctl->id;
30
31	if (reset_ctl->id < 0 || reset_ctl->id >= priv->nreset)
32		return -EINVAL;
33
34	dra7_reset_rmw(priv->rstctrl, 0x0, mask);
35
36	while ((readl(priv->rstst) & mask) != mask)
37		;
38
39	return 0;
40}
41
42static int dra7_reset_assert(struct reset_ctl *reset_ctl)
43{
44	struct dra7_reset_priv *priv = dev_get_priv(reset_ctl->dev);
45	int mask = 1 << reset_ctl->id;
46
47	if (reset_ctl->id < 0 || reset_ctl->id >= priv->nreset)
48		return -EINVAL;
49
50	dra7_reset_rmw(priv->rstctrl, mask, 0x0);
51
52	return 0;
53}
54
55struct reset_ops dra7_reset_ops = {
56	.rst_assert = dra7_reset_assert,
57	.rst_deassert = dra7_reset_deassert,
58};
59
60static const struct udevice_id dra7_reset_ids[] = {
61	{ .compatible = "ti,dra7-reset" },
62	{ }
63};
64
65static int dra7_reset_probe(struct udevice *dev)
66{
67	struct dra7_reset_priv *priv = dev_get_priv(dev);
68
69	priv->rstctrl = dev_read_addr(dev);
70	priv->rstst = priv->rstctrl + 0x4;
71	priv->nreset = dev_read_u32_default(dev, "ti,nresets", 1);
72
73	dev_info(dev, "dra7-reset successfully probed %s\n", dev->name);
74
75	return 0;
76}
77
78U_BOOT_DRIVER(dra7_reset) = {
79	.name = "dra7_reset",
80	.id = UCLASS_RESET,
81	.of_match = dra7_reset_ids,
82	.probe = dra7_reset_probe,
83	.ops = &dra7_reset_ops,
84	.priv_auto = sizeof(struct dra7_reset_priv),
85};
86