1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2021 Mark Kettenis <kettenis@openbsd.org>
4 */
5
6#include <common.h>
7#include <asm/io.h>
8#include <dm.h>
9#include <dm/device-internal.h>
10#include <linux/err.h>
11#include <linux/bitfield.h>
12#include <power-domain-uclass.h>
13#include <reset-uclass.h>
14#include <regmap.h>
15#include <syscon.h>
16
17#define APPLE_PMGR_RESET	BIT(31)
18#define APPLE_PMGR_DEV_DISABLE	BIT(10)
19#define APPLE_PMGR_WAS_CLKGATED	BIT(9)
20#define APPLE_PMGR_WAS_PWRGATED BIT(8)
21#define APPLE_PMGR_PS_ACTUAL	GENMASK(7, 4)
22#define APPLE_PMGR_PS_TARGET	GENMASK(3, 0)
23
24#define APPLE_PMGR_FLAGS	(APPLE_PMGR_WAS_CLKGATED | APPLE_PMGR_WAS_PWRGATED)
25
26#define APPLE_PMGR_PS_ACTIVE	0xf
27#define APPLE_PMGR_PS_PWRGATE	0x0
28
29#define APPLE_PMGR_PS_SET_TIMEOUT_US	100
30
31struct apple_pmgr_priv {
32	struct regmap *regmap;
33	u32 offset;		/* offset within regmap for this domain */
34};
35
36static int apple_reset_of_xlate(struct reset_ctl *reset_ctl,
37				struct ofnode_phandle_args *args)
38{
39	if (args->args_count != 0)
40		return -EINVAL;
41
42	return 0;
43}
44
45static int apple_reset_assert(struct reset_ctl *reset_ctl)
46{
47	struct apple_pmgr_priv *priv = dev_get_priv(reset_ctl->dev->parent);
48
49	regmap_update_bits(priv->regmap, priv->offset,
50			   APPLE_PMGR_FLAGS | APPLE_PMGR_DEV_DISABLE,
51			   APPLE_PMGR_DEV_DISABLE);
52	regmap_update_bits(priv->regmap, priv->offset,
53			   APPLE_PMGR_FLAGS | APPLE_PMGR_RESET,
54			   APPLE_PMGR_RESET);
55
56	return 0;
57}
58
59static int apple_reset_deassert(struct reset_ctl *reset_ctl)
60{
61	struct apple_pmgr_priv *priv = dev_get_priv(reset_ctl->dev->parent);
62
63	regmap_update_bits(priv->regmap, priv->offset,
64			   APPLE_PMGR_FLAGS | APPLE_PMGR_RESET, 0);
65	regmap_update_bits(priv->regmap, priv->offset,
66			   APPLE_PMGR_FLAGS | APPLE_PMGR_DEV_DISABLE, 0);
67
68	return 0;
69}
70
71struct reset_ops apple_reset_ops = {
72	.of_xlate = apple_reset_of_xlate,
73	.rst_assert = apple_reset_assert,
74	.rst_deassert = apple_reset_deassert,
75};
76
77static struct driver apple_reset_driver = {
78	.name = "apple_reset",
79	.id = UCLASS_RESET,
80	.ops = &apple_reset_ops,
81};
82
83static int apple_pmgr_ps_set(struct power_domain *power_domain, u32 pstate)
84{
85	struct apple_pmgr_priv *priv = dev_get_priv(power_domain->dev);
86	uint reg;
87
88	regmap_update_bits(priv->regmap, priv->offset, APPLE_PMGR_PS_TARGET,
89			   FIELD_PREP(APPLE_PMGR_PS_TARGET, pstate));
90
91	return regmap_read_poll_timeout(
92		priv->regmap, priv->offset, reg,
93		(FIELD_GET(APPLE_PMGR_PS_ACTUAL, reg) == pstate), 1,
94		APPLE_PMGR_PS_SET_TIMEOUT_US);
95}
96
97static int apple_pmgr_on(struct power_domain *power_domain)
98{
99	return apple_pmgr_ps_set(power_domain, APPLE_PMGR_PS_ACTIVE);
100}
101
102static int apple_pmgr_of_xlate(struct power_domain *power_domain,
103			       struct ofnode_phandle_args *args)
104{
105	if (args->args_count != 0) {
106		debug("Invalid args_count: %d\n", args->args_count);
107		return -EINVAL;
108	}
109
110	return 0;
111}
112
113static const struct udevice_id apple_pmgr_ids[] = {
114	{ .compatible = "apple,pmgr-pwrstate" },
115	{ /* sentinel */ }
116};
117
118static int apple_pmgr_probe(struct udevice *dev)
119{
120	struct apple_pmgr_priv *priv = dev_get_priv(dev);
121	struct udevice *child;
122	int ret;
123
124	ret = dev_power_domain_on(dev);
125	if (ret)
126		return ret;
127
128	priv->regmap = syscon_get_regmap(dev->parent);
129	if (IS_ERR(priv->regmap))
130		return PTR_ERR(priv->regmap);
131
132	ret = dev_read_u32(dev, "reg", &priv->offset);
133	if (ret < 0)
134		return ret;
135
136	device_bind(dev, &apple_reset_driver, "apple_reset", NULL,
137		    dev_ofnode(dev), &child);
138
139	return 0;
140}
141
142struct power_domain_ops apple_pmgr_ops = {
143	.on = apple_pmgr_on,
144	.of_xlate = apple_pmgr_of_xlate,
145};
146
147U_BOOT_DRIVER(apple_pmgr) = {
148	.name = "apple_pmgr",
149	.id = UCLASS_POWER_DOMAIN,
150	.of_match = apple_pmgr_ids,
151	.ops = &apple_pmgr_ops,
152	.probe = apple_pmgr_probe,
153	.priv_auto = sizeof(struct apple_pmgr_priv),
154};
155