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 	POWER_STATE_CHANGE_REQUESTED_NOTIFY = 0x7,
16 };
17 
18 enum scmi_power_protocol_notify {
19 	POWER_STATE_CHANGED = 0x0,
20 	POWER_STATE_CHANGE_REQUESTED = 0x1,
21 };
22 
23 struct scmi_msg_resp_power_attributes {
24 	__le16 num_domains;
25 	__le16 reserved;
26 	__le32 stats_addr_low;
27 	__le32 stats_addr_high;
28 	__le32 stats_size;
29 };
30 
31 struct scmi_msg_resp_power_domain_attributes {
32 	__le32 flags;
33 #define SUPPORTS_STATE_SET_NOTIFY(x)	((x) & BIT(31))
34 #define SUPPORTS_STATE_SET_ASYNC(x)	((x) & BIT(30))
35 #define SUPPORTS_STATE_SET_SYNC(x)	((x) & BIT(29))
36 	    u8 name[SCMI_MAX_STR_SIZE];
37 };
38 
39 struct scmi_power_set_state {
40 	__le32 flags;
41 #define STATE_SET_ASYNC		BIT(0)
42 	__le32 domain;
43 	__le32 state;
44 };
45 
46 struct scmi_power_state_notify {
47 	__le32 domain;
48 	__le32 notify_enable;
49 };
50 
51 struct power_dom_info {
52 	bool state_set_sync;
53 	bool state_set_async;
54 	bool state_set_notify;
55 	char name[SCMI_MAX_STR_SIZE];
56 };
57 
58 struct scmi_power_info {
59 	u32 version;
60 	int num_domains;
61 	u64 stats_addr;
62 	u32 stats_size;
63 	struct power_dom_info *dom_info;
64 };
65 
66 static int scmi_power_attributes_get(const struct scmi_handle *handle,
67 				     struct scmi_power_info *pi)
68 {
69 	int ret;
70 	struct scmi_xfer *t;
71 	struct scmi_msg_resp_power_attributes *attr;
72 
73 	ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
74 				 SCMI_PROTOCOL_POWER, 0, sizeof(*attr), &t);
75 	if (ret)
76 		return ret;
77 
78 	attr = t->rx.buf;
79 
80 	ret = scmi_do_xfer(handle, t);
81 	if (!ret) {
82 		pi->num_domains = le16_to_cpu(attr->num_domains);
83 		pi->stats_addr = le32_to_cpu(attr->stats_addr_low) |
84 				(u64)le32_to_cpu(attr->stats_addr_high) << 32;
85 		pi->stats_size = le32_to_cpu(attr->stats_size);
86 	}
87 
88 	scmi_xfer_put(handle, t);
89 	return ret;
90 }
91 
92 static int
93 scmi_power_domain_attributes_get(const struct scmi_handle *handle, u32 domain,
94 				 struct power_dom_info *dom_info)
95 {
96 	int ret;
97 	struct scmi_xfer *t;
98 	struct scmi_msg_resp_power_domain_attributes *attr;
99 
100 	ret = scmi_xfer_get_init(handle, POWER_DOMAIN_ATTRIBUTES,
101 				 SCMI_PROTOCOL_POWER, sizeof(domain),
102 				 sizeof(*attr), &t);
103 	if (ret)
104 		return ret;
105 
106 	put_unaligned_le32(domain, t->tx.buf);
107 	attr = t->rx.buf;
108 
109 	ret = scmi_do_xfer(handle, t);
110 	if (!ret) {
111 		u32 flags = le32_to_cpu(attr->flags);
112 
113 		dom_info->state_set_notify = SUPPORTS_STATE_SET_NOTIFY(flags);
114 		dom_info->state_set_async = SUPPORTS_STATE_SET_ASYNC(flags);
115 		dom_info->state_set_sync = SUPPORTS_STATE_SET_SYNC(flags);
116 		strlcpy(dom_info->name, attr->name, SCMI_MAX_STR_SIZE);
117 	}
118 
119 	scmi_xfer_put(handle, t);
120 	return ret;
121 }
122 
123 static int
124 scmi_power_state_set(const struct scmi_handle *handle, u32 domain, u32 state)
125 {
126 	int ret;
127 	struct scmi_xfer *t;
128 	struct scmi_power_set_state *st;
129 
130 	ret = scmi_xfer_get_init(handle, POWER_STATE_SET, SCMI_PROTOCOL_POWER,
131 				 sizeof(*st), 0, &t);
132 	if (ret)
133 		return ret;
134 
135 	st = t->tx.buf;
136 	st->flags = cpu_to_le32(0);
137 	st->domain = cpu_to_le32(domain);
138 	st->state = cpu_to_le32(state);
139 
140 	ret = scmi_do_xfer(handle, t);
141 
142 	scmi_xfer_put(handle, t);
143 	return ret;
144 }
145 
146 static int
147 scmi_power_state_get(const struct scmi_handle *handle, u32 domain, u32 *state)
148 {
149 	int ret;
150 	struct scmi_xfer *t;
151 
152 	ret = scmi_xfer_get_init(handle, POWER_STATE_GET, SCMI_PROTOCOL_POWER,
153 				 sizeof(u32), sizeof(u32), &t);
154 	if (ret)
155 		return ret;
156 
157 	put_unaligned_le32(domain, t->tx.buf);
158 
159 	ret = scmi_do_xfer(handle, t);
160 	if (!ret)
161 		*state = get_unaligned_le32(t->rx.buf);
162 
163 	scmi_xfer_put(handle, t);
164 	return ret;
165 }
166 
167 static int scmi_power_num_domains_get(const struct scmi_handle *handle)
168 {
169 	struct scmi_power_info *pi = handle->power_priv;
170 
171 	return pi->num_domains;
172 }
173 
174 static char *scmi_power_name_get(const struct scmi_handle *handle, u32 domain)
175 {
176 	struct scmi_power_info *pi = handle->power_priv;
177 	struct power_dom_info *dom = pi->dom_info + domain;
178 
179 	return dom->name;
180 }
181 
182 static struct scmi_power_ops power_ops = {
183 	.num_domains_get = scmi_power_num_domains_get,
184 	.name_get = scmi_power_name_get,
185 	.state_set = scmi_power_state_set,
186 	.state_get = scmi_power_state_get,
187 };
188 
189 static int scmi_power_protocol_init(struct scmi_handle *handle)
190 {
191 	int domain;
192 	u32 version;
193 	struct scmi_power_info *pinfo;
194 
195 	scmi_version_get(handle, SCMI_PROTOCOL_POWER, &version);
196 
197 	dev_dbg(handle->dev, "Power Version %d.%d\n",
198 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
199 
200 	pinfo = devm_kzalloc(handle->dev, sizeof(*pinfo), GFP_KERNEL);
201 	if (!pinfo)
202 		return -ENOMEM;
203 
204 	scmi_power_attributes_get(handle, pinfo);
205 
206 	pinfo->dom_info = devm_kcalloc(handle->dev, pinfo->num_domains,
207 				       sizeof(*pinfo->dom_info), GFP_KERNEL);
208 	if (!pinfo->dom_info)
209 		return -ENOMEM;
210 
211 	for (domain = 0; domain < pinfo->num_domains; domain++) {
212 		struct power_dom_info *dom = pinfo->dom_info + domain;
213 
214 		scmi_power_domain_attributes_get(handle, domain, dom);
215 	}
216 
217 	pinfo->version = version;
218 	handle->power_ops = &power_ops;
219 	handle->power_priv = pinfo;
220 
221 	return 0;
222 }
223 
224 static int __init scmi_power_init(void)
225 {
226 	return scmi_protocol_register(SCMI_PROTOCOL_POWER,
227 				      &scmi_power_protocol_init);
228 }
229 subsys_initcall(scmi_power_init);
230