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 enum scmi_sensor_protocol_notify {
18 	SENSOR_TRIP_POINT_EVENT = 0x0,
19 };
20 
21 struct scmi_msg_resp_sensor_attributes {
22 	__le16 num_sensors;
23 	u8 max_requests;
24 	u8 reserved;
25 	__le32 reg_addr_low;
26 	__le32 reg_addr_high;
27 	__le32 reg_size;
28 };
29 
30 struct scmi_msg_resp_sensor_description {
31 	__le16 num_returned;
32 	__le16 num_remaining;
33 	struct {
34 		__le32 id;
35 		__le32 attributes_low;
36 #define SUPPORTS_ASYNC_READ(x)	((x) & BIT(31))
37 #define NUM_TRIP_POINTS(x)	((x) & 0xff)
38 		__le32 attributes_high;
39 #define SENSOR_TYPE(x)		((x) & 0xff)
40 #define SENSOR_SCALE(x)		(((x) >> 11) & 0x1f)
41 #define SENSOR_SCALE_SIGN	BIT(4)
42 #define SENSOR_SCALE_EXTEND	GENMASK(7, 5)
43 #define SENSOR_UPDATE_SCALE(x)	(((x) >> 22) & 0x1f)
44 #define SENSOR_UPDATE_BASE(x)	(((x) >> 27) & 0x1f)
45 		    u8 name[SCMI_MAX_STR_SIZE];
46 	} desc[0];
47 };
48 
49 struct scmi_msg_sensor_trip_point_notify {
50 	__le32 id;
51 	__le32 event_control;
52 #define SENSOR_TP_NOTIFY_ALL	BIT(0)
53 };
54 
55 struct scmi_msg_set_sensor_trip_point {
56 	__le32 id;
57 	__le32 event_control;
58 #define SENSOR_TP_EVENT_MASK	(0x3)
59 #define SENSOR_TP_DISABLED	0x0
60 #define SENSOR_TP_POSITIVE	0x1
61 #define SENSOR_TP_NEGATIVE	0x2
62 #define SENSOR_TP_BOTH		0x3
63 #define SENSOR_TP_ID(x)		(((x) & 0xff) << 4)
64 	__le32 value_low;
65 	__le32 value_high;
66 };
67 
68 struct scmi_msg_sensor_reading_get {
69 	__le32 id;
70 	__le32 flags;
71 #define SENSOR_READ_ASYNC	BIT(0)
72 };
73 
74 struct sensors_info {
75 	u32 version;
76 	int num_sensors;
77 	int max_requests;
78 	u64 reg_addr;
79 	u32 reg_size;
80 	struct scmi_sensor_info *sensors;
81 };
82 
83 static int scmi_sensor_attributes_get(const struct scmi_handle *handle,
84 				      struct sensors_info *si)
85 {
86 	int ret;
87 	struct scmi_xfer *t;
88 	struct scmi_msg_resp_sensor_attributes *attr;
89 
90 	ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
91 				 SCMI_PROTOCOL_SENSOR, 0, sizeof(*attr), &t);
92 	if (ret)
93 		return ret;
94 
95 	attr = t->rx.buf;
96 
97 	ret = scmi_do_xfer(handle, t);
98 	if (!ret) {
99 		si->num_sensors = le16_to_cpu(attr->num_sensors);
100 		si->max_requests = attr->max_requests;
101 		si->reg_addr = le32_to_cpu(attr->reg_addr_low) |
102 				(u64)le32_to_cpu(attr->reg_addr_high) << 32;
103 		si->reg_size = le32_to_cpu(attr->reg_size);
104 	}
105 
106 	scmi_xfer_put(handle, t);
107 	return ret;
108 }
109 
110 static int scmi_sensor_description_get(const struct scmi_handle *handle,
111 				       struct sensors_info *si)
112 {
113 	int ret, cnt;
114 	u32 desc_index = 0;
115 	u16 num_returned, num_remaining;
116 	struct scmi_xfer *t;
117 	struct scmi_msg_resp_sensor_description *buf;
118 
119 	ret = scmi_xfer_get_init(handle, SENSOR_DESCRIPTION_GET,
120 				 SCMI_PROTOCOL_SENSOR, sizeof(__le32), 0, &t);
121 	if (ret)
122 		return ret;
123 
124 	buf = t->rx.buf;
125 
126 	do {
127 		/* Set the number of sensors to be skipped/already read */
128 		put_unaligned_le32(desc_index, t->tx.buf);
129 
130 		ret = scmi_do_xfer(handle, t);
131 		if (ret)
132 			break;
133 
134 		num_returned = le16_to_cpu(buf->num_returned);
135 		num_remaining = le16_to_cpu(buf->num_remaining);
136 
137 		if (desc_index + num_returned > si->num_sensors) {
138 			dev_err(handle->dev, "No. of sensors can't exceed %d",
139 				si->num_sensors);
140 			break;
141 		}
142 
143 		for (cnt = 0; cnt < num_returned; cnt++) {
144 			u32 attrh, attrl;
145 			struct scmi_sensor_info *s;
146 
147 			attrl = le32_to_cpu(buf->desc[cnt].attributes_low);
148 			attrh = le32_to_cpu(buf->desc[cnt].attributes_high);
149 			s = &si->sensors[desc_index + cnt];
150 			s->id = le32_to_cpu(buf->desc[cnt].id);
151 			s->type = SENSOR_TYPE(attrh);
152 			s->scale = SENSOR_SCALE(attrh);
153 			/* Sign extend to a full s8 */
154 			if (s->scale & SENSOR_SCALE_SIGN)
155 				s->scale |= SENSOR_SCALE_EXTEND;
156 			s->async = SUPPORTS_ASYNC_READ(attrl);
157 			s->num_trip_points = NUM_TRIP_POINTS(attrl);
158 			strlcpy(s->name, buf->desc[cnt].name, SCMI_MAX_STR_SIZE);
159 		}
160 
161 		desc_index += num_returned;
162 		/*
163 		 * check for both returned and remaining to avoid infinite
164 		 * loop due to buggy firmware
165 		 */
166 	} while (num_returned && num_remaining);
167 
168 	scmi_xfer_put(handle, t);
169 	return ret;
170 }
171 
172 static int scmi_sensor_trip_point_notify(const struct scmi_handle *handle,
173 					 u32 sensor_id, bool enable)
174 {
175 	int ret;
176 	u32 evt_cntl = enable ? SENSOR_TP_NOTIFY_ALL : 0;
177 	struct scmi_xfer *t;
178 	struct scmi_msg_sensor_trip_point_notify *cfg;
179 
180 	ret = scmi_xfer_get_init(handle, SENSOR_TRIP_POINT_NOTIFY,
181 				 SCMI_PROTOCOL_SENSOR, sizeof(*cfg), 0, &t);
182 	if (ret)
183 		return ret;
184 
185 	cfg = t->tx.buf;
186 	cfg->id = cpu_to_le32(sensor_id);
187 	cfg->event_control = cpu_to_le32(evt_cntl);
188 
189 	ret = scmi_do_xfer(handle, t);
190 
191 	scmi_xfer_put(handle, t);
192 	return ret;
193 }
194 
195 static int
196 scmi_sensor_trip_point_config(const struct scmi_handle *handle, u32 sensor_id,
197 			      u8 trip_id, u64 trip_value)
198 {
199 	int ret;
200 	u32 evt_cntl = SENSOR_TP_BOTH;
201 	struct scmi_xfer *t;
202 	struct scmi_msg_set_sensor_trip_point *trip;
203 
204 	ret = scmi_xfer_get_init(handle, SENSOR_TRIP_POINT_CONFIG,
205 				 SCMI_PROTOCOL_SENSOR, sizeof(*trip), 0, &t);
206 	if (ret)
207 		return ret;
208 
209 	trip = t->tx.buf;
210 	trip->id = cpu_to_le32(sensor_id);
211 	trip->event_control = cpu_to_le32(evt_cntl | SENSOR_TP_ID(trip_id));
212 	trip->value_low = cpu_to_le32(trip_value & 0xffffffff);
213 	trip->value_high = cpu_to_le32(trip_value >> 32);
214 
215 	ret = scmi_do_xfer(handle, t);
216 
217 	scmi_xfer_put(handle, t);
218 	return ret;
219 }
220 
221 static int scmi_sensor_reading_get(const struct scmi_handle *handle,
222 				   u32 sensor_id, u64 *value)
223 {
224 	int ret;
225 	struct scmi_xfer *t;
226 	struct scmi_msg_sensor_reading_get *sensor;
227 	struct sensors_info *si = handle->sensor_priv;
228 	struct scmi_sensor_info *s = si->sensors + sensor_id;
229 
230 	ret = scmi_xfer_get_init(handle, SENSOR_READING_GET,
231 				 SCMI_PROTOCOL_SENSOR, sizeof(*sensor),
232 				 sizeof(u64), &t);
233 	if (ret)
234 		return ret;
235 
236 	sensor = t->tx.buf;
237 	sensor->id = cpu_to_le32(sensor_id);
238 
239 	if (s->async) {
240 		sensor->flags = cpu_to_le32(SENSOR_READ_ASYNC);
241 		ret = scmi_do_xfer_with_response(handle, t);
242 		if (!ret)
243 			*value = get_unaligned_le64((void *)
244 						    ((__le32 *)t->rx.buf + 1));
245 	} else {
246 		sensor->flags = cpu_to_le32(0);
247 		ret = scmi_do_xfer(handle, t);
248 		if (!ret)
249 			*value = get_unaligned_le64(t->rx.buf);
250 	}
251 
252 	scmi_xfer_put(handle, t);
253 	return ret;
254 }
255 
256 static const struct scmi_sensor_info *
257 scmi_sensor_info_get(const struct scmi_handle *handle, u32 sensor_id)
258 {
259 	struct sensors_info *si = handle->sensor_priv;
260 
261 	return si->sensors + sensor_id;
262 }
263 
264 static int scmi_sensor_count_get(const struct scmi_handle *handle)
265 {
266 	struct sensors_info *si = handle->sensor_priv;
267 
268 	return si->num_sensors;
269 }
270 
271 static struct scmi_sensor_ops sensor_ops = {
272 	.count_get = scmi_sensor_count_get,
273 	.info_get = scmi_sensor_info_get,
274 	.trip_point_notify = scmi_sensor_trip_point_notify,
275 	.trip_point_config = scmi_sensor_trip_point_config,
276 	.reading_get = scmi_sensor_reading_get,
277 };
278 
279 static int scmi_sensors_protocol_init(struct scmi_handle *handle)
280 {
281 	u32 version;
282 	struct sensors_info *sinfo;
283 
284 	scmi_version_get(handle, SCMI_PROTOCOL_SENSOR, &version);
285 
286 	dev_dbg(handle->dev, "Sensor Version %d.%d\n",
287 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
288 
289 	sinfo = devm_kzalloc(handle->dev, sizeof(*sinfo), GFP_KERNEL);
290 	if (!sinfo)
291 		return -ENOMEM;
292 
293 	scmi_sensor_attributes_get(handle, sinfo);
294 
295 	sinfo->sensors = devm_kcalloc(handle->dev, sinfo->num_sensors,
296 				      sizeof(*sinfo->sensors), GFP_KERNEL);
297 	if (!sinfo->sensors)
298 		return -ENOMEM;
299 
300 	scmi_sensor_description_get(handle, sinfo);
301 
302 	sinfo->version = version;
303 	handle->sensor_ops = &sensor_ops;
304 	handle->sensor_priv = sinfo;
305 
306 	return 0;
307 }
308 
309 static int __init scmi_sensors_init(void)
310 {
311 	return scmi_protocol_register(SCMI_PROTOCOL_SENSOR,
312 				      &scmi_sensors_protocol_init);
313 }
314 subsys_initcall(scmi_sensors_init);
315