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