1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * System Control and Management Interface (SCMI) Sensor Protocol
4  *
5  * Copyright (C) 2018 ARM Ltd.
6  */
7 
8 #include "common.h"
9 
10 enum scmi_sensor_protocol_cmd {
11 	SENSOR_DESCRIPTION_GET = 0x3,
12 	SENSOR_TRIP_POINT_NOTIFY = 0x4,
13 	SENSOR_TRIP_POINT_CONFIG = 0x5,
14 	SENSOR_READING_GET = 0x6,
15 };
16 
17 struct scmi_msg_resp_sensor_attributes {
18 	__le16 num_sensors;
19 	u8 max_requests;
20 	u8 reserved;
21 	__le32 reg_addr_low;
22 	__le32 reg_addr_high;
23 	__le32 reg_size;
24 };
25 
26 struct scmi_msg_resp_sensor_description {
27 	__le16 num_returned;
28 	__le16 num_remaining;
29 	struct {
30 		__le32 id;
31 		__le32 attributes_low;
32 #define SUPPORTS_ASYNC_READ(x)	((x) & BIT(31))
33 #define NUM_TRIP_POINTS(x)	((x) & 0xff)
34 		__le32 attributes_high;
35 #define SENSOR_TYPE(x)		((x) & 0xff)
36 #define SENSOR_SCALE(x)		(((x) >> 11) & 0x1f)
37 #define SENSOR_SCALE_SIGN	BIT(4)
38 #define SENSOR_SCALE_EXTEND	GENMASK(7, 5)
39 #define SENSOR_UPDATE_SCALE(x)	(((x) >> 22) & 0x1f)
40 #define SENSOR_UPDATE_BASE(x)	(((x) >> 27) & 0x1f)
41 		    u8 name[SCMI_MAX_STR_SIZE];
42 	} desc[0];
43 };
44 
45 struct scmi_msg_sensor_trip_point_notify {
46 	__le32 id;
47 	__le32 event_control;
48 #define SENSOR_TP_NOTIFY_ALL	BIT(0)
49 };
50 
51 struct scmi_msg_set_sensor_trip_point {
52 	__le32 id;
53 	__le32 event_control;
54 #define SENSOR_TP_EVENT_MASK	(0x3)
55 #define SENSOR_TP_DISABLED	0x0
56 #define SENSOR_TP_POSITIVE	0x1
57 #define SENSOR_TP_NEGATIVE	0x2
58 #define SENSOR_TP_BOTH		0x3
59 #define SENSOR_TP_ID(x)		(((x) & 0xff) << 4)
60 	__le32 value_low;
61 	__le32 value_high;
62 };
63 
64 struct scmi_msg_sensor_reading_get {
65 	__le32 id;
66 	__le32 flags;
67 #define SENSOR_READ_ASYNC	BIT(0)
68 };
69 
70 struct sensors_info {
71 	u32 version;
72 	int num_sensors;
73 	int max_requests;
74 	u64 reg_addr;
75 	u32 reg_size;
76 	struct scmi_sensor_info *sensors;
77 };
78 
79 static int scmi_sensor_attributes_get(const struct scmi_handle *handle,
80 				      struct sensors_info *si)
81 {
82 	int ret;
83 	struct scmi_xfer *t;
84 	struct scmi_msg_resp_sensor_attributes *attr;
85 
86 	ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
87 				 SCMI_PROTOCOL_SENSOR, 0, sizeof(*attr), &t);
88 	if (ret)
89 		return ret;
90 
91 	attr = t->rx.buf;
92 
93 	ret = scmi_do_xfer(handle, t);
94 	if (!ret) {
95 		si->num_sensors = le16_to_cpu(attr->num_sensors);
96 		si->max_requests = attr->max_requests;
97 		si->reg_addr = le32_to_cpu(attr->reg_addr_low) |
98 				(u64)le32_to_cpu(attr->reg_addr_high) << 32;
99 		si->reg_size = le32_to_cpu(attr->reg_size);
100 	}
101 
102 	scmi_xfer_put(handle, t);
103 	return ret;
104 }
105 
106 static int scmi_sensor_description_get(const struct scmi_handle *handle,
107 				       struct sensors_info *si)
108 {
109 	int ret, cnt;
110 	u32 desc_index = 0;
111 	u16 num_returned, num_remaining;
112 	struct scmi_xfer *t;
113 	struct scmi_msg_resp_sensor_description *buf;
114 
115 	ret = scmi_xfer_get_init(handle, SENSOR_DESCRIPTION_GET,
116 				 SCMI_PROTOCOL_SENSOR, sizeof(__le32), 0, &t);
117 	if (ret)
118 		return ret;
119 
120 	buf = t->rx.buf;
121 
122 	do {
123 		/* Set the number of sensors to be skipped/already read */
124 		put_unaligned_le32(desc_index, t->tx.buf);
125 
126 		ret = scmi_do_xfer(handle, t);
127 		if (ret)
128 			break;
129 
130 		num_returned = le16_to_cpu(buf->num_returned);
131 		num_remaining = le16_to_cpu(buf->num_remaining);
132 
133 		if (desc_index + num_returned > si->num_sensors) {
134 			dev_err(handle->dev, "No. of sensors can't exceed %d",
135 				si->num_sensors);
136 			break;
137 		}
138 
139 		for (cnt = 0; cnt < num_returned; cnt++) {
140 			u32 attrh, attrl;
141 			struct scmi_sensor_info *s;
142 
143 			attrl = le32_to_cpu(buf->desc[cnt].attributes_low);
144 			attrh = le32_to_cpu(buf->desc[cnt].attributes_high);
145 			s = &si->sensors[desc_index + cnt];
146 			s->id = le32_to_cpu(buf->desc[cnt].id);
147 			s->type = SENSOR_TYPE(attrh);
148 			s->scale = SENSOR_SCALE(attrh);
149 			/* Sign extend to a full s8 */
150 			if (s->scale & SENSOR_SCALE_SIGN)
151 				s->scale |= SENSOR_SCALE_EXTEND;
152 			s->async = SUPPORTS_ASYNC_READ(attrl);
153 			s->num_trip_points = NUM_TRIP_POINTS(attrl);
154 			strlcpy(s->name, buf->desc[cnt].name, SCMI_MAX_STR_SIZE);
155 		}
156 
157 		desc_index += num_returned;
158 		/*
159 		 * check for both returned and remaining to avoid infinite
160 		 * loop due to buggy firmware
161 		 */
162 	} while (num_returned && num_remaining);
163 
164 	scmi_xfer_put(handle, t);
165 	return ret;
166 }
167 
168 static int scmi_sensor_trip_point_notify(const struct scmi_handle *handle,
169 					 u32 sensor_id, bool enable)
170 {
171 	int ret;
172 	u32 evt_cntl = enable ? SENSOR_TP_NOTIFY_ALL : 0;
173 	struct scmi_xfer *t;
174 	struct scmi_msg_sensor_trip_point_notify *cfg;
175 
176 	ret = scmi_xfer_get_init(handle, SENSOR_TRIP_POINT_NOTIFY,
177 				 SCMI_PROTOCOL_SENSOR, sizeof(*cfg), 0, &t);
178 	if (ret)
179 		return ret;
180 
181 	cfg = t->tx.buf;
182 	cfg->id = cpu_to_le32(sensor_id);
183 	cfg->event_control = cpu_to_le32(evt_cntl);
184 
185 	ret = scmi_do_xfer(handle, t);
186 
187 	scmi_xfer_put(handle, t);
188 	return ret;
189 }
190 
191 static int
192 scmi_sensor_trip_point_config(const struct scmi_handle *handle, u32 sensor_id,
193 			      u8 trip_id, u64 trip_value)
194 {
195 	int ret;
196 	u32 evt_cntl = SENSOR_TP_BOTH;
197 	struct scmi_xfer *t;
198 	struct scmi_msg_set_sensor_trip_point *trip;
199 
200 	ret = scmi_xfer_get_init(handle, SENSOR_TRIP_POINT_CONFIG,
201 				 SCMI_PROTOCOL_SENSOR, sizeof(*trip), 0, &t);
202 	if (ret)
203 		return ret;
204 
205 	trip = t->tx.buf;
206 	trip->id = cpu_to_le32(sensor_id);
207 	trip->event_control = cpu_to_le32(evt_cntl | SENSOR_TP_ID(trip_id));
208 	trip->value_low = cpu_to_le32(trip_value & 0xffffffff);
209 	trip->value_high = cpu_to_le32(trip_value >> 32);
210 
211 	ret = scmi_do_xfer(handle, t);
212 
213 	scmi_xfer_put(handle, t);
214 	return ret;
215 }
216 
217 static int scmi_sensor_reading_get(const struct scmi_handle *handle,
218 				   u32 sensor_id, u64 *value)
219 {
220 	int ret;
221 	struct scmi_xfer *t;
222 	struct scmi_msg_sensor_reading_get *sensor;
223 	struct sensors_info *si = handle->sensor_priv;
224 	struct scmi_sensor_info *s = si->sensors + sensor_id;
225 
226 	ret = scmi_xfer_get_init(handle, SENSOR_READING_GET,
227 				 SCMI_PROTOCOL_SENSOR, sizeof(*sensor),
228 				 sizeof(u64), &t);
229 	if (ret)
230 		return ret;
231 
232 	sensor = t->tx.buf;
233 	sensor->id = cpu_to_le32(sensor_id);
234 
235 	if (s->async) {
236 		sensor->flags = cpu_to_le32(SENSOR_READ_ASYNC);
237 		ret = scmi_do_xfer_with_response(handle, t);
238 		if (!ret)
239 			*value = get_unaligned_le64((void *)
240 						    ((__le32 *)t->rx.buf + 1));
241 	} else {
242 		sensor->flags = cpu_to_le32(0);
243 		ret = scmi_do_xfer(handle, t);
244 		if (!ret)
245 			*value = get_unaligned_le64(t->rx.buf);
246 	}
247 
248 	scmi_xfer_put(handle, t);
249 	return ret;
250 }
251 
252 static const struct scmi_sensor_info *
253 scmi_sensor_info_get(const struct scmi_handle *handle, u32 sensor_id)
254 {
255 	struct sensors_info *si = handle->sensor_priv;
256 
257 	return si->sensors + sensor_id;
258 }
259 
260 static int scmi_sensor_count_get(const struct scmi_handle *handle)
261 {
262 	struct sensors_info *si = handle->sensor_priv;
263 
264 	return si->num_sensors;
265 }
266 
267 static struct scmi_sensor_ops sensor_ops = {
268 	.count_get = scmi_sensor_count_get,
269 	.info_get = scmi_sensor_info_get,
270 	.trip_point_notify = scmi_sensor_trip_point_notify,
271 	.trip_point_config = scmi_sensor_trip_point_config,
272 	.reading_get = scmi_sensor_reading_get,
273 };
274 
275 static int scmi_sensors_protocol_init(struct scmi_handle *handle)
276 {
277 	u32 version;
278 	struct sensors_info *sinfo;
279 
280 	scmi_version_get(handle, SCMI_PROTOCOL_SENSOR, &version);
281 
282 	dev_dbg(handle->dev, "Sensor Version %d.%d\n",
283 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
284 
285 	sinfo = devm_kzalloc(handle->dev, sizeof(*sinfo), GFP_KERNEL);
286 	if (!sinfo)
287 		return -ENOMEM;
288 
289 	scmi_sensor_attributes_get(handle, sinfo);
290 
291 	sinfo->sensors = devm_kcalloc(handle->dev, sinfo->num_sensors,
292 				      sizeof(*sinfo->sensors), GFP_KERNEL);
293 	if (!sinfo->sensors)
294 		return -ENOMEM;
295 
296 	scmi_sensor_description_get(handle, sinfo);
297 
298 	sinfo->version = version;
299 	handle->sensor_ops = &sensor_ops;
300 	handle->sensor_priv = sinfo;
301 
302 	return 0;
303 }
304 
305 static int __init scmi_sensors_init(void)
306 {
307 	return scmi_protocol_register(SCMI_PROTOCOL_SENSOR,
308 				      &scmi_sensors_protocol_init);
309 }
310 subsys_initcall(scmi_sensors_init);
311