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