1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * System Control and Management Interface(SCMI) based hwmon sensor driver |
4 | * |
5 | * Copyright (C) 2018-2021 ARM Ltd. |
6 | * Sudeep Holla <sudeep.holla@arm.com> |
7 | */ |
8 | |
9 | #include <linux/hwmon.h> |
10 | #include <linux/module.h> |
11 | #include <linux/scmi_protocol.h> |
12 | #include <linux/slab.h> |
13 | #include <linux/sysfs.h> |
14 | #include <linux/thermal.h> |
15 | |
16 | static const struct scmi_sensor_proto_ops *sensor_ops; |
17 | |
18 | struct scmi_sensors { |
19 | const struct scmi_protocol_handle *ph; |
20 | const struct scmi_sensor_info **info[hwmon_max]; |
21 | }; |
22 | |
23 | struct scmi_thermal_sensor { |
24 | const struct scmi_protocol_handle *ph; |
25 | const struct scmi_sensor_info *info; |
26 | }; |
27 | |
28 | static inline u64 __pow10(u8 x) |
29 | { |
30 | u64 r = 1; |
31 | |
32 | while (x--) |
33 | r *= 10; |
34 | |
35 | return r; |
36 | } |
37 | |
38 | static int scmi_hwmon_scale(const struct scmi_sensor_info *sensor, u64 *value) |
39 | { |
40 | int scale = sensor->scale; |
41 | u64 f; |
42 | |
43 | switch (sensor->type) { |
44 | case TEMPERATURE_C: |
45 | case VOLTAGE: |
46 | case CURRENT: |
47 | scale += 3; |
48 | break; |
49 | case POWER: |
50 | case ENERGY: |
51 | scale += 6; |
52 | break; |
53 | default: |
54 | break; |
55 | } |
56 | |
57 | if (scale == 0) |
58 | return 0; |
59 | |
60 | if (abs(scale) > 19) |
61 | return -E2BIG; |
62 | |
63 | f = __pow10(abs(scale)); |
64 | if (scale > 0) |
65 | *value *= f; |
66 | else |
67 | *value = div64_u64(dividend: *value, divisor: f); |
68 | |
69 | return 0; |
70 | } |
71 | |
72 | static int scmi_hwmon_read_scaled_value(const struct scmi_protocol_handle *ph, |
73 | const struct scmi_sensor_info *sensor, |
74 | long *val) |
75 | { |
76 | int ret; |
77 | u64 value; |
78 | |
79 | ret = sensor_ops->reading_get(ph, sensor->id, &value); |
80 | if (ret) |
81 | return ret; |
82 | |
83 | ret = scmi_hwmon_scale(sensor, value: &value); |
84 | if (!ret) |
85 | *val = value; |
86 | |
87 | return ret; |
88 | } |
89 | |
90 | static int scmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type, |
91 | u32 attr, int channel, long *val) |
92 | { |
93 | const struct scmi_sensor_info *sensor; |
94 | struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev); |
95 | |
96 | sensor = *(scmi_sensors->info[type] + channel); |
97 | |
98 | return scmi_hwmon_read_scaled_value(ph: scmi_sensors->ph, sensor, val); |
99 | } |
100 | |
101 | static int |
102 | scmi_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type, |
103 | u32 attr, int channel, const char **str) |
104 | { |
105 | const struct scmi_sensor_info *sensor; |
106 | struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev); |
107 | |
108 | sensor = *(scmi_sensors->info[type] + channel); |
109 | *str = sensor->name; |
110 | |
111 | return 0; |
112 | } |
113 | |
114 | static umode_t |
115 | scmi_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type, |
116 | u32 attr, int channel) |
117 | { |
118 | const struct scmi_sensor_info *sensor; |
119 | const struct scmi_sensors *scmi_sensors = drvdata; |
120 | |
121 | sensor = *(scmi_sensors->info[type] + channel); |
122 | if (sensor) |
123 | return 0444; |
124 | |
125 | return 0; |
126 | } |
127 | |
128 | static const struct hwmon_ops scmi_hwmon_ops = { |
129 | .is_visible = scmi_hwmon_is_visible, |
130 | .read = scmi_hwmon_read, |
131 | .read_string = scmi_hwmon_read_string, |
132 | }; |
133 | |
134 | static struct hwmon_chip_info scmi_chip_info = { |
135 | .ops = &scmi_hwmon_ops, |
136 | .info = NULL, |
137 | }; |
138 | |
139 | static int scmi_hwmon_thermal_get_temp(struct thermal_zone_device *tz, |
140 | int *temp) |
141 | { |
142 | int ret; |
143 | long value; |
144 | struct scmi_thermal_sensor *th_sensor = thermal_zone_device_priv(tzd: tz); |
145 | |
146 | ret = scmi_hwmon_read_scaled_value(ph: th_sensor->ph, sensor: th_sensor->info, |
147 | val: &value); |
148 | if (!ret) |
149 | *temp = value; |
150 | |
151 | return ret; |
152 | } |
153 | |
154 | static const struct thermal_zone_device_ops scmi_hwmon_thermal_ops = { |
155 | .get_temp = scmi_hwmon_thermal_get_temp, |
156 | }; |
157 | |
158 | static int scmi_hwmon_add_chan_info(struct hwmon_channel_info *scmi_hwmon_chan, |
159 | struct device *dev, int num, |
160 | enum hwmon_sensor_types type, u32 config) |
161 | { |
162 | int i; |
163 | u32 *cfg = devm_kcalloc(dev, n: num + 1, size: sizeof(*cfg), GFP_KERNEL); |
164 | |
165 | if (!cfg) |
166 | return -ENOMEM; |
167 | |
168 | scmi_hwmon_chan->type = type; |
169 | scmi_hwmon_chan->config = cfg; |
170 | for (i = 0; i < num; i++, cfg++) |
171 | *cfg = config; |
172 | |
173 | return 0; |
174 | } |
175 | |
176 | static enum hwmon_sensor_types scmi_types[] = { |
177 | [TEMPERATURE_C] = hwmon_temp, |
178 | [VOLTAGE] = hwmon_in, |
179 | [CURRENT] = hwmon_curr, |
180 | [POWER] = hwmon_power, |
181 | [ENERGY] = hwmon_energy, |
182 | }; |
183 | |
184 | static u32 hwmon_attributes[hwmon_max] = { |
185 | [hwmon_temp] = HWMON_T_INPUT | HWMON_T_LABEL, |
186 | [hwmon_in] = HWMON_I_INPUT | HWMON_I_LABEL, |
187 | [hwmon_curr] = HWMON_C_INPUT | HWMON_C_LABEL, |
188 | [hwmon_power] = HWMON_P_INPUT | HWMON_P_LABEL, |
189 | [hwmon_energy] = HWMON_E_INPUT | HWMON_E_LABEL, |
190 | }; |
191 | |
192 | static int scmi_thermal_sensor_register(struct device *dev, |
193 | const struct scmi_protocol_handle *ph, |
194 | const struct scmi_sensor_info *sensor) |
195 | { |
196 | struct scmi_thermal_sensor *th_sensor; |
197 | struct thermal_zone_device *tzd; |
198 | |
199 | th_sensor = devm_kzalloc(dev, size: sizeof(*th_sensor), GFP_KERNEL); |
200 | if (!th_sensor) |
201 | return -ENOMEM; |
202 | |
203 | th_sensor->ph = ph; |
204 | th_sensor->info = sensor; |
205 | |
206 | /* |
207 | * Try to register a temperature sensor with the Thermal Framework: |
208 | * skip sensors not defined as part of any thermal zone (-ENODEV) but |
209 | * report any other errors related to misconfigured zones/sensors. |
210 | */ |
211 | tzd = devm_thermal_of_zone_register(dev, id: th_sensor->info->id, data: th_sensor, |
212 | ops: &scmi_hwmon_thermal_ops); |
213 | if (IS_ERR(ptr: tzd)) { |
214 | devm_kfree(dev, p: th_sensor); |
215 | |
216 | if (PTR_ERR(ptr: tzd) != -ENODEV) |
217 | return PTR_ERR(ptr: tzd); |
218 | |
219 | dev_dbg(dev, "Sensor '%s' not attached to any thermal zone.\n" , |
220 | sensor->name); |
221 | } else { |
222 | dev_dbg(dev, "Sensor '%s' attached to thermal zone ID:%d\n" , |
223 | sensor->name, thermal_zone_device_id(tzd)); |
224 | } |
225 | |
226 | return 0; |
227 | } |
228 | |
229 | static int scmi_hwmon_probe(struct scmi_device *sdev) |
230 | { |
231 | int i, idx; |
232 | u16 nr_sensors; |
233 | enum hwmon_sensor_types type; |
234 | struct scmi_sensors *scmi_sensors; |
235 | const struct scmi_sensor_info *sensor; |
236 | int nr_count[hwmon_max] = {0}, nr_types = 0, nr_count_temp = 0; |
237 | const struct hwmon_chip_info *chip_info; |
238 | struct device *hwdev, *dev = &sdev->dev; |
239 | struct hwmon_channel_info *scmi_hwmon_chan; |
240 | const struct hwmon_channel_info **ptr_scmi_ci; |
241 | const struct scmi_handle *handle = sdev->handle; |
242 | struct scmi_protocol_handle *ph; |
243 | |
244 | if (!handle) |
245 | return -ENODEV; |
246 | |
247 | sensor_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_SENSOR, &ph); |
248 | if (IS_ERR(ptr: sensor_ops)) |
249 | return PTR_ERR(ptr: sensor_ops); |
250 | |
251 | nr_sensors = sensor_ops->count_get(ph); |
252 | if (!nr_sensors) |
253 | return -EIO; |
254 | |
255 | scmi_sensors = devm_kzalloc(dev, size: sizeof(*scmi_sensors), GFP_KERNEL); |
256 | if (!scmi_sensors) |
257 | return -ENOMEM; |
258 | |
259 | scmi_sensors->ph = ph; |
260 | |
261 | for (i = 0; i < nr_sensors; i++) { |
262 | sensor = sensor_ops->info_get(ph, i); |
263 | if (!sensor) |
264 | return -EINVAL; |
265 | |
266 | switch (sensor->type) { |
267 | case TEMPERATURE_C: |
268 | case VOLTAGE: |
269 | case CURRENT: |
270 | case POWER: |
271 | case ENERGY: |
272 | type = scmi_types[sensor->type]; |
273 | if (!nr_count[type]) |
274 | nr_types++; |
275 | nr_count[type]++; |
276 | break; |
277 | } |
278 | } |
279 | |
280 | if (nr_count[hwmon_temp]) |
281 | nr_count_temp = nr_count[hwmon_temp]; |
282 | |
283 | scmi_hwmon_chan = devm_kcalloc(dev, n: nr_types, size: sizeof(*scmi_hwmon_chan), |
284 | GFP_KERNEL); |
285 | if (!scmi_hwmon_chan) |
286 | return -ENOMEM; |
287 | |
288 | ptr_scmi_ci = devm_kcalloc(dev, n: nr_types + 1, size: sizeof(*ptr_scmi_ci), |
289 | GFP_KERNEL); |
290 | if (!ptr_scmi_ci) |
291 | return -ENOMEM; |
292 | |
293 | scmi_chip_info.info = ptr_scmi_ci; |
294 | chip_info = &scmi_chip_info; |
295 | |
296 | for (type = 0; type < hwmon_max; type++) { |
297 | if (!nr_count[type]) |
298 | continue; |
299 | |
300 | scmi_hwmon_add_chan_info(scmi_hwmon_chan, dev, num: nr_count[type], |
301 | type, config: hwmon_attributes[type]); |
302 | *ptr_scmi_ci++ = scmi_hwmon_chan++; |
303 | |
304 | scmi_sensors->info[type] = |
305 | devm_kcalloc(dev, n: nr_count[type], |
306 | size: sizeof(*scmi_sensors->info), GFP_KERNEL); |
307 | if (!scmi_sensors->info[type]) |
308 | return -ENOMEM; |
309 | } |
310 | |
311 | for (i = nr_sensors - 1; i >= 0 ; i--) { |
312 | sensor = sensor_ops->info_get(ph, i); |
313 | if (!sensor) |
314 | continue; |
315 | |
316 | switch (sensor->type) { |
317 | case TEMPERATURE_C: |
318 | case VOLTAGE: |
319 | case CURRENT: |
320 | case POWER: |
321 | case ENERGY: |
322 | type = scmi_types[sensor->type]; |
323 | idx = --nr_count[type]; |
324 | *(scmi_sensors->info[type] + idx) = sensor; |
325 | break; |
326 | } |
327 | } |
328 | |
329 | hwdev = devm_hwmon_device_register_with_info(dev, name: "scmi_sensors" , |
330 | drvdata: scmi_sensors, info: chip_info, |
331 | NULL); |
332 | if (IS_ERR(ptr: hwdev)) |
333 | return PTR_ERR(ptr: hwdev); |
334 | |
335 | for (i = 0; i < nr_count_temp; i++) { |
336 | int ret; |
337 | |
338 | sensor = *(scmi_sensors->info[hwmon_temp] + i); |
339 | if (!sensor) |
340 | continue; |
341 | |
342 | /* |
343 | * Warn on any misconfiguration related to thermal zones but |
344 | * bail out of probing only on memory errors. |
345 | */ |
346 | ret = scmi_thermal_sensor_register(dev, ph, sensor); |
347 | if (ret) { |
348 | if (ret == -ENOMEM) |
349 | return ret; |
350 | dev_warn(dev, |
351 | "Thermal zone misconfigured for %s. err=%d\n" , |
352 | sensor->name, ret); |
353 | } |
354 | } |
355 | |
356 | return 0; |
357 | } |
358 | |
359 | static const struct scmi_device_id scmi_id_table[] = { |
360 | { SCMI_PROTOCOL_SENSOR, "hwmon" }, |
361 | { }, |
362 | }; |
363 | MODULE_DEVICE_TABLE(scmi, scmi_id_table); |
364 | |
365 | static struct scmi_driver scmi_hwmon_drv = { |
366 | .name = "scmi-hwmon" , |
367 | .probe = scmi_hwmon_probe, |
368 | .id_table = scmi_id_table, |
369 | }; |
370 | module_scmi_driver(scmi_hwmon_drv); |
371 | |
372 | MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>" ); |
373 | MODULE_DESCRIPTION("ARM SCMI HWMON interface driver" ); |
374 | MODULE_LICENSE("GPL v2" ); |
375 | |