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
31 struct apple_pmgr_priv {
32 struct regmap *regmap;
33 u32 offset; /* offset within regmap for this domain */
34 };
35
apple_reset_of_xlate(struct reset_ctl * reset_ctl,struct ofnode_phandle_args * args)36 static 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
apple_reset_assert(struct reset_ctl * reset_ctl)45 static 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
apple_reset_deassert(struct reset_ctl * reset_ctl)59 static 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
71 struct 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
77 static struct driver apple_reset_driver = {
78 .name = "apple_reset",
79 .id = UCLASS_RESET,
80 .ops = &apple_reset_ops,
81 };
82
apple_pmgr_ps_set(struct power_domain * power_domain,u32 pstate)83 static 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
apple_pmgr_on(struct power_domain * power_domain)97 static int apple_pmgr_on(struct power_domain *power_domain)
98 {
99 return apple_pmgr_ps_set(power_domain, APPLE_PMGR_PS_ACTIVE);
100 }
101
apple_pmgr_of_xlate(struct power_domain * power_domain,struct ofnode_phandle_args * args)102 static 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
113 static const struct udevice_id apple_pmgr_ids[] = {
114 { .compatible = "apple,pmgr-pwrstate" },
115 { /* sentinel */ }
116 };
117
apple_pmgr_probe(struct udevice * dev)118 static 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
142 struct power_domain_ops apple_pmgr_ops = {
143 .on = apple_pmgr_on,
144 .of_xlate = apple_pmgr_of_xlate,
145 };
146
147 U_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