1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * System Control and Management Interface (SCMI) Power Protocol
4  *
5  * Copyright (C) 2018 ARM Ltd.
6  */
7 
8 #include "common.h"
9 
10 enum scmi_power_protocol_cmd {
11 	POWER_DOMAIN_ATTRIBUTES = 0x3,
12 	POWER_STATE_SET = 0x4,
13 	POWER_STATE_GET = 0x5,
14 	POWER_STATE_NOTIFY = 0x6,
15 };
16 
17 struct scmi_msg_resp_power_attributes {
18 	__le16 num_domains;
19 	__le16 reserved;
20 	__le32 stats_addr_low;
21 	__le32 stats_addr_high;
22 	__le32 stats_size;
23 };
24 
25 struct scmi_msg_resp_power_domain_attributes {
26 	__le32 flags;
27 #define SUPPORTS_STATE_SET_NOTIFY(x)	((x) & BIT(31))
28 #define SUPPORTS_STATE_SET_ASYNC(x)	((x) & BIT(30))
29 #define SUPPORTS_STATE_SET_SYNC(x)	((x) & BIT(29))
30 	    u8 name[SCMI_MAX_STR_SIZE];
31 };
32 
33 struct scmi_power_set_state {
34 	__le32 flags;
35 #define STATE_SET_ASYNC		BIT(0)
36 	__le32 domain;
37 	__le32 state;
38 };
39 
40 struct scmi_power_state_notify {
41 	__le32 domain;
42 	__le32 notify_enable;
43 };
44 
45 struct power_dom_info {
46 	bool state_set_sync;
47 	bool state_set_async;
48 	bool state_set_notify;
49 	char name[SCMI_MAX_STR_SIZE];
50 };
51 
52 struct scmi_power_info {
53 	int num_domains;
54 	u64 stats_addr;
55 	u32 stats_size;
56 	struct power_dom_info *dom_info;
57 };
58 
59 static int scmi_power_attributes_get(const struct scmi_handle *handle,
60 				     struct scmi_power_info *pi)
61 {
62 	int ret;
63 	struct scmi_xfer *t;
64 	struct scmi_msg_resp_power_attributes *attr;
65 
66 	ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
67 				 SCMI_PROTOCOL_POWER, 0, sizeof(*attr), &t);
68 	if (ret)
69 		return ret;
70 
71 	attr = t->rx.buf;
72 
73 	ret = scmi_do_xfer(handle, t);
74 	if (!ret) {
75 		pi->num_domains = le16_to_cpu(attr->num_domains);
76 		pi->stats_addr = le32_to_cpu(attr->stats_addr_low) |
77 				(u64)le32_to_cpu(attr->stats_addr_high) << 32;
78 		pi->stats_size = le32_to_cpu(attr->stats_size);
79 	}
80 
81 	scmi_xfer_put(handle, t);
82 	return ret;
83 }
84 
85 static int
86 scmi_power_domain_attributes_get(const struct scmi_handle *handle, u32 domain,
87 				 struct power_dom_info *dom_info)
88 {
89 	int ret;
90 	struct scmi_xfer *t;
91 	struct scmi_msg_resp_power_domain_attributes *attr;
92 
93 	ret = scmi_xfer_get_init(handle, POWER_DOMAIN_ATTRIBUTES,
94 				 SCMI_PROTOCOL_POWER, sizeof(domain),
95 				 sizeof(*attr), &t);
96 	if (ret)
97 		return ret;
98 
99 	*(__le32 *)t->tx.buf = cpu_to_le32(domain);
100 	attr = t->rx.buf;
101 
102 	ret = scmi_do_xfer(handle, t);
103 	if (!ret) {
104 		u32 flags = le32_to_cpu(attr->flags);
105 
106 		dom_info->state_set_notify = SUPPORTS_STATE_SET_NOTIFY(flags);
107 		dom_info->state_set_async = SUPPORTS_STATE_SET_ASYNC(flags);
108 		dom_info->state_set_sync = SUPPORTS_STATE_SET_SYNC(flags);
109 		strlcpy(dom_info->name, attr->name, SCMI_MAX_STR_SIZE);
110 	}
111 
112 	scmi_xfer_put(handle, t);
113 	return ret;
114 }
115 
116 static int
117 scmi_power_state_set(const struct scmi_handle *handle, u32 domain, u32 state)
118 {
119 	int ret;
120 	struct scmi_xfer *t;
121 	struct scmi_power_set_state *st;
122 
123 	ret = scmi_xfer_get_init(handle, POWER_STATE_SET, SCMI_PROTOCOL_POWER,
124 				 sizeof(*st), 0, &t);
125 	if (ret)
126 		return ret;
127 
128 	st = t->tx.buf;
129 	st->flags = cpu_to_le32(0);
130 	st->domain = cpu_to_le32(domain);
131 	st->state = cpu_to_le32(state);
132 
133 	ret = scmi_do_xfer(handle, t);
134 
135 	scmi_xfer_put(handle, t);
136 	return ret;
137 }
138 
139 static int
140 scmi_power_state_get(const struct scmi_handle *handle, u32 domain, u32 *state)
141 {
142 	int ret;
143 	struct scmi_xfer *t;
144 
145 	ret = scmi_xfer_get_init(handle, POWER_STATE_GET, SCMI_PROTOCOL_POWER,
146 				 sizeof(u32), sizeof(u32), &t);
147 	if (ret)
148 		return ret;
149 
150 	*(__le32 *)t->tx.buf = cpu_to_le32(domain);
151 
152 	ret = scmi_do_xfer(handle, t);
153 	if (!ret)
154 		*state = le32_to_cpu(*(__le32 *)t->rx.buf);
155 
156 	scmi_xfer_put(handle, t);
157 	return ret;
158 }
159 
160 static int scmi_power_num_domains_get(const struct scmi_handle *handle)
161 {
162 	struct scmi_power_info *pi = handle->power_priv;
163 
164 	return pi->num_domains;
165 }
166 
167 static char *scmi_power_name_get(const struct scmi_handle *handle, u32 domain)
168 {
169 	struct scmi_power_info *pi = handle->power_priv;
170 	struct power_dom_info *dom = pi->dom_info + domain;
171 
172 	return dom->name;
173 }
174 
175 static struct scmi_power_ops power_ops = {
176 	.num_domains_get = scmi_power_num_domains_get,
177 	.name_get = scmi_power_name_get,
178 	.state_set = scmi_power_state_set,
179 	.state_get = scmi_power_state_get,
180 };
181 
182 static int scmi_power_protocol_init(struct scmi_handle *handle)
183 {
184 	int domain;
185 	u32 version;
186 	struct scmi_power_info *pinfo;
187 
188 	scmi_version_get(handle, SCMI_PROTOCOL_POWER, &version);
189 
190 	dev_dbg(handle->dev, "Power Version %d.%d\n",
191 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
192 
193 	pinfo = devm_kzalloc(handle->dev, sizeof(*pinfo), GFP_KERNEL);
194 	if (!pinfo)
195 		return -ENOMEM;
196 
197 	scmi_power_attributes_get(handle, pinfo);
198 
199 	pinfo->dom_info = devm_kcalloc(handle->dev, pinfo->num_domains,
200 				       sizeof(*pinfo->dom_info), GFP_KERNEL);
201 	if (!pinfo->dom_info)
202 		return -ENOMEM;
203 
204 	for (domain = 0; domain < pinfo->num_domains; domain++) {
205 		struct power_dom_info *dom = pinfo->dom_info + domain;
206 
207 		scmi_power_domain_attributes_get(handle, domain, dom);
208 	}
209 
210 	handle->power_ops = &power_ops;
211 	handle->power_priv = pinfo;
212 
213 	return 0;
214 }
215 
216 static int __init scmi_power_init(void)
217 {
218 	return scmi_protocol_register(SCMI_PROTOCOL_POWER,
219 				      &scmi_power_protocol_init);
220 }
221 subsys_initcall(scmi_power_init);
222