1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * System Control and Management Interface (SCMI) Voltage Protocol
4 *
5 * Copyright (C) 2020-2021 ARM Ltd.
6 */
7
8 #include <linux/module.h>
9 #include <linux/scmi_protocol.h>
10
11 #include "common.h"
12
13 #define VOLTAGE_DOMS_NUM_MASK GENMASK(15, 0)
14 #define REMAINING_LEVELS_MASK GENMASK(31, 16)
15 #define RETURNED_LEVELS_MASK GENMASK(11, 0)
16
17 enum scmi_voltage_protocol_cmd {
18 VOLTAGE_DOMAIN_ATTRIBUTES = 0x3,
19 VOLTAGE_DESCRIBE_LEVELS = 0x4,
20 VOLTAGE_CONFIG_SET = 0x5,
21 VOLTAGE_CONFIG_GET = 0x6,
22 VOLTAGE_LEVEL_SET = 0x7,
23 VOLTAGE_LEVEL_GET = 0x8,
24 };
25
26 #define NUM_VOLTAGE_DOMAINS(x) ((u16)(FIELD_GET(VOLTAGE_DOMS_NUM_MASK, (x))))
27
28 struct scmi_msg_resp_domain_attributes {
29 __le32 attr;
30 u8 name[SCMI_MAX_STR_SIZE];
31 };
32
33 struct scmi_msg_cmd_describe_levels {
34 __le32 domain_id;
35 __le32 level_index;
36 };
37
38 struct scmi_msg_resp_describe_levels {
39 __le32 flags;
40 #define NUM_REMAINING_LEVELS(f) ((u16)(FIELD_GET(REMAINING_LEVELS_MASK, (f))))
41 #define NUM_RETURNED_LEVELS(f) ((u16)(FIELD_GET(RETURNED_LEVELS_MASK, (f))))
42 #define SUPPORTS_SEGMENTED_LEVELS(f) ((f) & BIT(12))
43 __le32 voltage[];
44 };
45
46 struct scmi_msg_cmd_config_set {
47 __le32 domain_id;
48 __le32 config;
49 };
50
51 struct scmi_msg_cmd_level_set {
52 __le32 domain_id;
53 __le32 flags;
54 __le32 voltage_level;
55 };
56
57 struct voltage_info {
58 unsigned int version;
59 unsigned int num_domains;
60 struct scmi_voltage_info *domains;
61 };
62
scmi_protocol_attributes_get(const struct scmi_protocol_handle * ph,struct voltage_info * vinfo)63 static int scmi_protocol_attributes_get(const struct scmi_protocol_handle *ph,
64 struct voltage_info *vinfo)
65 {
66 int ret;
67 struct scmi_xfer *t;
68
69 ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0,
70 sizeof(__le32), &t);
71 if (ret)
72 return ret;
73
74 ret = ph->xops->do_xfer(ph, t);
75 if (!ret)
76 vinfo->num_domains =
77 NUM_VOLTAGE_DOMAINS(get_unaligned_le32(t->rx.buf));
78
79 ph->xops->xfer_put(ph, t);
80 return ret;
81 }
82
scmi_init_voltage_levels(struct device * dev,struct scmi_voltage_info * v,u32 num_returned,u32 num_remaining,bool segmented)83 static int scmi_init_voltage_levels(struct device *dev,
84 struct scmi_voltage_info *v,
85 u32 num_returned, u32 num_remaining,
86 bool segmented)
87 {
88 u32 num_levels;
89
90 num_levels = num_returned + num_remaining;
91 /*
92 * segmented levels entries are represented by a single triplet
93 * returned all in one go.
94 */
95 if (!num_levels ||
96 (segmented && (num_remaining || num_returned != 3))) {
97 dev_err(dev,
98 "Invalid level descriptor(%d/%d/%d) for voltage dom %d\n",
99 num_levels, num_returned, num_remaining, v->id);
100 return -EINVAL;
101 }
102
103 v->levels_uv = devm_kcalloc(dev, num_levels, sizeof(u32), GFP_KERNEL);
104 if (!v->levels_uv)
105 return -ENOMEM;
106
107 v->num_levels = num_levels;
108 v->segmented = segmented;
109
110 return 0;
111 }
112
scmi_voltage_descriptors_get(const struct scmi_protocol_handle * ph,struct voltage_info * vinfo)113 static int scmi_voltage_descriptors_get(const struct scmi_protocol_handle *ph,
114 struct voltage_info *vinfo)
115 {
116 int ret, dom;
117 struct scmi_xfer *td, *tl;
118 struct device *dev = ph->dev;
119 struct scmi_msg_resp_domain_attributes *resp_dom;
120 struct scmi_msg_resp_describe_levels *resp_levels;
121
122 ret = ph->xops->xfer_get_init(ph, VOLTAGE_DOMAIN_ATTRIBUTES,
123 sizeof(__le32), sizeof(*resp_dom), &td);
124 if (ret)
125 return ret;
126 resp_dom = td->rx.buf;
127
128 ret = ph->xops->xfer_get_init(ph, VOLTAGE_DESCRIBE_LEVELS,
129 sizeof(__le64), 0, &tl);
130 if (ret)
131 goto outd;
132 resp_levels = tl->rx.buf;
133
134 for (dom = 0; dom < vinfo->num_domains; dom++) {
135 u32 desc_index = 0;
136 u16 num_returned = 0, num_remaining = 0;
137 struct scmi_msg_cmd_describe_levels *cmd;
138 struct scmi_voltage_info *v;
139
140 /* Retrieve domain attributes at first ... */
141 put_unaligned_le32(dom, td->tx.buf);
142 ret = ph->xops->do_xfer(ph, td);
143 /* Skip domain on comms error */
144 if (ret)
145 continue;
146
147 v = vinfo->domains + dom;
148 v->id = dom;
149 v->attributes = le32_to_cpu(resp_dom->attr);
150 strlcpy(v->name, resp_dom->name, SCMI_MAX_STR_SIZE);
151
152 cmd = tl->tx.buf;
153 /* ...then retrieve domain levels descriptions */
154 do {
155 u32 flags;
156 int cnt;
157
158 cmd->domain_id = cpu_to_le32(v->id);
159 cmd->level_index = cpu_to_le32(desc_index);
160 ret = ph->xops->do_xfer(ph, tl);
161 if (ret)
162 break;
163
164 flags = le32_to_cpu(resp_levels->flags);
165 num_returned = NUM_RETURNED_LEVELS(flags);
166 num_remaining = NUM_REMAINING_LEVELS(flags);
167
168 /* Allocate space for num_levels if not already done */
169 if (!v->num_levels) {
170 ret = scmi_init_voltage_levels(dev, v,
171 num_returned,
172 num_remaining,
173 SUPPORTS_SEGMENTED_LEVELS(flags));
174 if (ret)
175 break;
176 }
177
178 if (desc_index + num_returned > v->num_levels) {
179 dev_err(ph->dev,
180 "No. of voltage levels can't exceed %d\n",
181 v->num_levels);
182 ret = -EINVAL;
183 break;
184 }
185
186 for (cnt = 0; cnt < num_returned; cnt++) {
187 s32 val;
188
189 val =
190 (s32)le32_to_cpu(resp_levels->voltage[cnt]);
191 v->levels_uv[desc_index + cnt] = val;
192 if (val < 0)
193 v->negative_volts_allowed = true;
194 }
195
196 desc_index += num_returned;
197
198 ph->xops->reset_rx_to_maxsz(ph, tl);
199 /* check both to avoid infinite loop due to buggy fw */
200 } while (num_returned && num_remaining);
201
202 if (ret) {
203 v->num_levels = 0;
204 devm_kfree(dev, v->levels_uv);
205 }
206
207 ph->xops->reset_rx_to_maxsz(ph, td);
208 }
209
210 ph->xops->xfer_put(ph, tl);
211 outd:
212 ph->xops->xfer_put(ph, td);
213
214 return ret;
215 }
216
__scmi_voltage_get_u32(const struct scmi_protocol_handle * ph,u8 cmd_id,u32 domain_id,u32 * value)217 static int __scmi_voltage_get_u32(const struct scmi_protocol_handle *ph,
218 u8 cmd_id, u32 domain_id, u32 *value)
219 {
220 int ret;
221 struct scmi_xfer *t;
222 struct voltage_info *vinfo = ph->get_priv(ph);
223
224 if (domain_id >= vinfo->num_domains)
225 return -EINVAL;
226
227 ret = ph->xops->xfer_get_init(ph, cmd_id, sizeof(__le32), 0, &t);
228 if (ret)
229 return ret;
230
231 put_unaligned_le32(domain_id, t->tx.buf);
232 ret = ph->xops->do_xfer(ph, t);
233 if (!ret)
234 *value = get_unaligned_le32(t->rx.buf);
235
236 ph->xops->xfer_put(ph, t);
237 return ret;
238 }
239
scmi_voltage_config_set(const struct scmi_protocol_handle * ph,u32 domain_id,u32 config)240 static int scmi_voltage_config_set(const struct scmi_protocol_handle *ph,
241 u32 domain_id, u32 config)
242 {
243 int ret;
244 struct scmi_xfer *t;
245 struct voltage_info *vinfo = ph->get_priv(ph);
246 struct scmi_msg_cmd_config_set *cmd;
247
248 if (domain_id >= vinfo->num_domains)
249 return -EINVAL;
250
251 ret = ph->xops->xfer_get_init(ph, VOLTAGE_CONFIG_SET,
252 sizeof(*cmd), 0, &t);
253 if (ret)
254 return ret;
255
256 cmd = t->tx.buf;
257 cmd->domain_id = cpu_to_le32(domain_id);
258 cmd->config = cpu_to_le32(config & GENMASK(3, 0));
259
260 ret = ph->xops->do_xfer(ph, t);
261
262 ph->xops->xfer_put(ph, t);
263 return ret;
264 }
265
scmi_voltage_config_get(const struct scmi_protocol_handle * ph,u32 domain_id,u32 * config)266 static int scmi_voltage_config_get(const struct scmi_protocol_handle *ph,
267 u32 domain_id, u32 *config)
268 {
269 return __scmi_voltage_get_u32(ph, VOLTAGE_CONFIG_GET,
270 domain_id, config);
271 }
272
scmi_voltage_level_set(const struct scmi_protocol_handle * ph,u32 domain_id,u32 flags,s32 volt_uV)273 static int scmi_voltage_level_set(const struct scmi_protocol_handle *ph,
274 u32 domain_id, u32 flags, s32 volt_uV)
275 {
276 int ret;
277 struct scmi_xfer *t;
278 struct voltage_info *vinfo = ph->get_priv(ph);
279 struct scmi_msg_cmd_level_set *cmd;
280
281 if (domain_id >= vinfo->num_domains)
282 return -EINVAL;
283
284 ret = ph->xops->xfer_get_init(ph, VOLTAGE_LEVEL_SET,
285 sizeof(*cmd), 0, &t);
286 if (ret)
287 return ret;
288
289 cmd = t->tx.buf;
290 cmd->domain_id = cpu_to_le32(domain_id);
291 cmd->flags = cpu_to_le32(flags);
292 cmd->voltage_level = cpu_to_le32(volt_uV);
293
294 ret = ph->xops->do_xfer(ph, t);
295
296 ph->xops->xfer_put(ph, t);
297 return ret;
298 }
299
scmi_voltage_level_get(const struct scmi_protocol_handle * ph,u32 domain_id,s32 * volt_uV)300 static int scmi_voltage_level_get(const struct scmi_protocol_handle *ph,
301 u32 domain_id, s32 *volt_uV)
302 {
303 return __scmi_voltage_get_u32(ph, VOLTAGE_LEVEL_GET,
304 domain_id, (u32 *)volt_uV);
305 }
306
307 static const struct scmi_voltage_info * __must_check
scmi_voltage_info_get(const struct scmi_protocol_handle * ph,u32 domain_id)308 scmi_voltage_info_get(const struct scmi_protocol_handle *ph, u32 domain_id)
309 {
310 struct voltage_info *vinfo = ph->get_priv(ph);
311
312 if (domain_id >= vinfo->num_domains ||
313 !vinfo->domains[domain_id].num_levels)
314 return NULL;
315
316 return vinfo->domains + domain_id;
317 }
318
scmi_voltage_domains_num_get(const struct scmi_protocol_handle * ph)319 static int scmi_voltage_domains_num_get(const struct scmi_protocol_handle *ph)
320 {
321 struct voltage_info *vinfo = ph->get_priv(ph);
322
323 return vinfo->num_domains;
324 }
325
326 static struct scmi_voltage_proto_ops voltage_proto_ops = {
327 .num_domains_get = scmi_voltage_domains_num_get,
328 .info_get = scmi_voltage_info_get,
329 .config_set = scmi_voltage_config_set,
330 .config_get = scmi_voltage_config_get,
331 .level_set = scmi_voltage_level_set,
332 .level_get = scmi_voltage_level_get,
333 };
334
scmi_voltage_protocol_init(const struct scmi_protocol_handle * ph)335 static int scmi_voltage_protocol_init(const struct scmi_protocol_handle *ph)
336 {
337 int ret;
338 u32 version;
339 struct voltage_info *vinfo;
340
341 ret = ph->xops->version_get(ph, &version);
342 if (ret)
343 return ret;
344
345 dev_dbg(ph->dev, "Voltage Version %d.%d\n",
346 PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
347
348 vinfo = devm_kzalloc(ph->dev, sizeof(*vinfo), GFP_KERNEL);
349 if (!vinfo)
350 return -ENOMEM;
351 vinfo->version = version;
352
353 ret = scmi_protocol_attributes_get(ph, vinfo);
354 if (ret)
355 return ret;
356
357 if (vinfo->num_domains) {
358 vinfo->domains = devm_kcalloc(ph->dev, vinfo->num_domains,
359 sizeof(*vinfo->domains),
360 GFP_KERNEL);
361 if (!vinfo->domains)
362 return -ENOMEM;
363 ret = scmi_voltage_descriptors_get(ph, vinfo);
364 if (ret)
365 return ret;
366 } else {
367 dev_warn(ph->dev, "No Voltage domains found.\n");
368 }
369
370 return ph->set_priv(ph, vinfo);
371 }
372
373 static const struct scmi_protocol scmi_voltage = {
374 .id = SCMI_PROTOCOL_VOLTAGE,
375 .owner = THIS_MODULE,
376 .instance_init = &scmi_voltage_protocol_init,
377 .ops = &voltage_proto_ops,
378 };
379
380 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(voltage, scmi_voltage)
381