1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * power_supply_hwmon.c - power supply hwmon support.
4 */
5
6 #include <linux/err.h>
7 #include <linux/hwmon.h>
8 #include <linux/power_supply.h>
9 #include <linux/slab.h>
10 #include "power_supply.h"
11
12 struct power_supply_hwmon {
13 struct power_supply *psy;
14 unsigned long *props;
15 };
16
17 static const char *const ps_temp_label[] = {
18 "temp",
19 "ambient temp",
20 };
21
power_supply_hwmon_in_to_property(u32 attr)22 static int power_supply_hwmon_in_to_property(u32 attr)
23 {
24 switch (attr) {
25 case hwmon_in_average:
26 return POWER_SUPPLY_PROP_VOLTAGE_AVG;
27 case hwmon_in_min:
28 return POWER_SUPPLY_PROP_VOLTAGE_MIN;
29 case hwmon_in_max:
30 return POWER_SUPPLY_PROP_VOLTAGE_MAX;
31 case hwmon_in_input:
32 return POWER_SUPPLY_PROP_VOLTAGE_NOW;
33 default:
34 return -EINVAL;
35 }
36 }
37
power_supply_hwmon_curr_to_property(u32 attr)38 static int power_supply_hwmon_curr_to_property(u32 attr)
39 {
40 switch (attr) {
41 case hwmon_curr_average:
42 return POWER_SUPPLY_PROP_CURRENT_AVG;
43 case hwmon_curr_max:
44 return POWER_SUPPLY_PROP_CURRENT_MAX;
45 case hwmon_curr_input:
46 return POWER_SUPPLY_PROP_CURRENT_NOW;
47 default:
48 return -EINVAL;
49 }
50 }
51
power_supply_hwmon_power_to_property(u32 attr)52 static int power_supply_hwmon_power_to_property(u32 attr)
53 {
54 switch (attr) {
55 case hwmon_power_input:
56 return POWER_SUPPLY_PROP_POWER_NOW;
57 case hwmon_power_average:
58 return POWER_SUPPLY_PROP_POWER_AVG;
59 default:
60 return -EINVAL;
61 }
62 }
63
power_supply_hwmon_temp_to_property(u32 attr,int channel)64 static int power_supply_hwmon_temp_to_property(u32 attr, int channel)
65 {
66 if (channel) {
67 switch (attr) {
68 case hwmon_temp_input:
69 return POWER_SUPPLY_PROP_TEMP_AMBIENT;
70 case hwmon_temp_min_alarm:
71 return POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MIN;
72 case hwmon_temp_max_alarm:
73 return POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MAX;
74 default:
75 break;
76 }
77 } else {
78 switch (attr) {
79 case hwmon_temp_input:
80 return POWER_SUPPLY_PROP_TEMP;
81 case hwmon_temp_max:
82 return POWER_SUPPLY_PROP_TEMP_MAX;
83 case hwmon_temp_min:
84 return POWER_SUPPLY_PROP_TEMP_MIN;
85 case hwmon_temp_min_alarm:
86 return POWER_SUPPLY_PROP_TEMP_ALERT_MIN;
87 case hwmon_temp_max_alarm:
88 return POWER_SUPPLY_PROP_TEMP_ALERT_MAX;
89 default:
90 break;
91 }
92 }
93
94 return -EINVAL;
95 }
96
97 static int
power_supply_hwmon_to_property(enum hwmon_sensor_types type,u32 attr,int channel)98 power_supply_hwmon_to_property(enum hwmon_sensor_types type,
99 u32 attr, int channel)
100 {
101 switch (type) {
102 case hwmon_in:
103 return power_supply_hwmon_in_to_property(attr);
104 case hwmon_curr:
105 return power_supply_hwmon_curr_to_property(attr);
106 case hwmon_power:
107 return power_supply_hwmon_power_to_property(attr);
108 case hwmon_temp:
109 return power_supply_hwmon_temp_to_property(attr, channel);
110 default:
111 return -EINVAL;
112 }
113 }
114
power_supply_hwmon_is_a_label(enum hwmon_sensor_types type,u32 attr)115 static bool power_supply_hwmon_is_a_label(enum hwmon_sensor_types type,
116 u32 attr)
117 {
118 return type == hwmon_temp && attr == hwmon_temp_label;
119 }
120
121 struct hwmon_type_attr_list {
122 const u32 *attrs;
123 size_t n_attrs;
124 };
125
126 static const u32 ps_temp_attrs[] = {
127 hwmon_temp_input,
128 hwmon_temp_min, hwmon_temp_max,
129 hwmon_temp_min_alarm, hwmon_temp_max_alarm,
130 };
131
132 static const struct hwmon_type_attr_list ps_type_attrs[hwmon_max] = {
133 [hwmon_temp] = { ps_temp_attrs, ARRAY_SIZE(ps_temp_attrs) },
134 };
135
power_supply_hwmon_has_input(const struct power_supply_hwmon * psyhw,enum hwmon_sensor_types type,int channel)136 static bool power_supply_hwmon_has_input(
137 const struct power_supply_hwmon *psyhw,
138 enum hwmon_sensor_types type, int channel)
139 {
140 const struct hwmon_type_attr_list *attr_list = &ps_type_attrs[type];
141 size_t i;
142
143 for (i = 0; i < attr_list->n_attrs; ++i) {
144 int prop = power_supply_hwmon_to_property(type,
145 attr_list->attrs[i], channel);
146
147 if (prop >= 0 && test_bit(prop, psyhw->props))
148 return true;
149 }
150
151 return false;
152 }
153
power_supply_hwmon_is_writable(enum hwmon_sensor_types type,u32 attr)154 static bool power_supply_hwmon_is_writable(enum hwmon_sensor_types type,
155 u32 attr)
156 {
157 switch (type) {
158 case hwmon_in:
159 return attr == hwmon_in_min ||
160 attr == hwmon_in_max;
161 case hwmon_curr:
162 return attr == hwmon_curr_max;
163 case hwmon_temp:
164 return attr == hwmon_temp_max ||
165 attr == hwmon_temp_min ||
166 attr == hwmon_temp_min_alarm ||
167 attr == hwmon_temp_max_alarm;
168 default:
169 return false;
170 }
171 }
172
power_supply_hwmon_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)173 static umode_t power_supply_hwmon_is_visible(const void *data,
174 enum hwmon_sensor_types type,
175 u32 attr, int channel)
176 {
177 const struct power_supply_hwmon *psyhw = data;
178 int prop;
179
180 if (power_supply_hwmon_is_a_label(type, attr)) {
181 if (power_supply_hwmon_has_input(psyhw, type, channel))
182 return 0444;
183 else
184 return 0;
185 }
186
187 prop = power_supply_hwmon_to_property(type, attr, channel);
188 if (prop < 0 || !test_bit(prop, psyhw->props))
189 return 0;
190
191 if (power_supply_property_is_writeable(psyhw->psy, prop) > 0 &&
192 power_supply_hwmon_is_writable(type, attr))
193 return 0644;
194
195 return 0444;
196 }
197
power_supply_hwmon_read_string(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,const char ** str)198 static int power_supply_hwmon_read_string(struct device *dev,
199 enum hwmon_sensor_types type,
200 u32 attr, int channel,
201 const char **str)
202 {
203 switch (type) {
204 case hwmon_temp:
205 *str = ps_temp_label[channel];
206 break;
207 default:
208 /* unreachable, but see:
209 * gcc bug #51513 [1] and clang bug #978 [2]
210 *
211 * [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51513
212 * [2] https://github.com/ClangBuiltLinux/linux/issues/978
213 */
214 break;
215 }
216
217 return 0;
218 }
219
220 static int
power_supply_hwmon_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)221 power_supply_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
222 u32 attr, int channel, long *val)
223 {
224 struct power_supply_hwmon *psyhw = dev_get_drvdata(dev);
225 struct power_supply *psy = psyhw->psy;
226 union power_supply_propval pspval;
227 int ret, prop;
228
229 prop = power_supply_hwmon_to_property(type, attr, channel);
230 if (prop < 0)
231 return prop;
232
233 ret = power_supply_get_property(psy, prop, &pspval);
234 if (ret)
235 return ret;
236
237 switch (type) {
238 /*
239 * Both voltage and current is reported in units of
240 * microvolts/microamps, so we need to adjust it to
241 * milliamps(volts)
242 */
243 case hwmon_curr:
244 case hwmon_in:
245 pspval.intval = DIV_ROUND_CLOSEST(pspval.intval, 1000);
246 break;
247 case hwmon_power:
248 /*
249 * Power properties are already in microwatts.
250 */
251 break;
252 /*
253 * Temp needs to be converted from 1/10 C to milli-C
254 */
255 case hwmon_temp:
256 if (check_mul_overflow(pspval.intval, 100,
257 &pspval.intval))
258 return -EOVERFLOW;
259 break;
260 default:
261 return -EINVAL;
262 }
263
264 *val = pspval.intval;
265
266 return 0;
267 }
268
269 static int
power_supply_hwmon_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)270 power_supply_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
271 u32 attr, int channel, long val)
272 {
273 struct power_supply_hwmon *psyhw = dev_get_drvdata(dev);
274 struct power_supply *psy = psyhw->psy;
275 union power_supply_propval pspval;
276 int prop;
277
278 prop = power_supply_hwmon_to_property(type, attr, channel);
279 if (prop < 0)
280 return prop;
281
282 pspval.intval = val;
283
284 switch (type) {
285 /*
286 * Both voltage and current is reported in units of
287 * microvolts/microamps, so we need to adjust it to
288 * milliamps(volts)
289 */
290 case hwmon_curr:
291 case hwmon_in:
292 if (check_mul_overflow(pspval.intval, 1000,
293 &pspval.intval))
294 return -EOVERFLOW;
295 break;
296 /*
297 * Temp needs to be converted from 1/10 C to milli-C
298 */
299 case hwmon_temp:
300 pspval.intval = DIV_ROUND_CLOSEST(pspval.intval, 100);
301 break;
302 default:
303 return -EINVAL;
304 }
305
306 return power_supply_set_property(psy, prop, &pspval);
307 }
308
309 static const struct hwmon_ops power_supply_hwmon_ops = {
310 .is_visible = power_supply_hwmon_is_visible,
311 .read = power_supply_hwmon_read,
312 .write = power_supply_hwmon_write,
313 .read_string = power_supply_hwmon_read_string,
314 };
315
316 static const struct hwmon_channel_info * const power_supply_hwmon_info[] = {
317 HWMON_CHANNEL_INFO(temp,
318 HWMON_T_LABEL |
319 HWMON_T_INPUT |
320 HWMON_T_MAX |
321 HWMON_T_MIN |
322 HWMON_T_MIN_ALARM |
323 HWMON_T_MAX_ALARM,
324
325 HWMON_T_LABEL |
326 HWMON_T_INPUT |
327 HWMON_T_MIN_ALARM |
328 HWMON_T_MAX_ALARM),
329
330 HWMON_CHANNEL_INFO(curr,
331 HWMON_C_AVERAGE |
332 HWMON_C_MAX |
333 HWMON_C_INPUT),
334
335 HWMON_CHANNEL_INFO(power,
336 HWMON_P_INPUT |
337 HWMON_P_AVERAGE),
338
339 HWMON_CHANNEL_INFO(in,
340 HWMON_I_AVERAGE |
341 HWMON_I_MIN |
342 HWMON_I_MAX |
343 HWMON_I_INPUT),
344 NULL
345 };
346
347 static const struct hwmon_chip_info power_supply_hwmon_chip_info = {
348 .ops = &power_supply_hwmon_ops,
349 .info = power_supply_hwmon_info,
350 };
351
power_supply_add_hwmon_sysfs(struct power_supply * psy)352 int power_supply_add_hwmon_sysfs(struct power_supply *psy)
353 {
354 const struct power_supply_desc *desc = psy->desc;
355 struct power_supply_hwmon *psyhw;
356 struct device *dev = &psy->dev;
357 struct device *hwmon;
358 int ret, i;
359 const char *name;
360
361 if (!devres_open_group(dev, power_supply_add_hwmon_sysfs,
362 GFP_KERNEL))
363 return -ENOMEM;
364
365 psyhw = devm_kzalloc(dev, sizeof(*psyhw), GFP_KERNEL);
366 if (!psyhw) {
367 ret = -ENOMEM;
368 goto error;
369 }
370
371 psyhw->psy = psy;
372 psyhw->props = devm_bitmap_zalloc(dev,
373 POWER_SUPPLY_PROP_TIME_TO_FULL_AVG + 1,
374 GFP_KERNEL);
375 if (!psyhw->props) {
376 ret = -ENOMEM;
377 goto error;
378 }
379
380 for (i = 0; i < desc->num_properties; i++) {
381 const enum power_supply_property prop = desc->properties[i];
382
383 switch (prop) {
384 case POWER_SUPPLY_PROP_CURRENT_AVG:
385 case POWER_SUPPLY_PROP_CURRENT_MAX:
386 case POWER_SUPPLY_PROP_CURRENT_NOW:
387 case POWER_SUPPLY_PROP_POWER_AVG:
388 case POWER_SUPPLY_PROP_POWER_NOW:
389 case POWER_SUPPLY_PROP_TEMP:
390 case POWER_SUPPLY_PROP_TEMP_MAX:
391 case POWER_SUPPLY_PROP_TEMP_MIN:
392 case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
393 case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
394 case POWER_SUPPLY_PROP_TEMP_AMBIENT:
395 case POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MIN:
396 case POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MAX:
397 case POWER_SUPPLY_PROP_VOLTAGE_AVG:
398 case POWER_SUPPLY_PROP_VOLTAGE_MIN:
399 case POWER_SUPPLY_PROP_VOLTAGE_MAX:
400 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
401 set_bit(prop, psyhw->props);
402 break;
403 default:
404 break;
405 }
406 }
407
408 name = psy->desc->name;
409 if (strchr(name, '-')) {
410 char *new_name;
411
412 new_name = devm_kstrdup(dev, name, GFP_KERNEL);
413 if (!new_name) {
414 ret = -ENOMEM;
415 goto error;
416 }
417 strreplace(new_name, '-', '_');
418 name = new_name;
419 }
420 hwmon = devm_hwmon_device_register_with_info(dev, name,
421 psyhw,
422 &power_supply_hwmon_chip_info,
423 NULL);
424 ret = PTR_ERR_OR_ZERO(hwmon);
425 if (ret)
426 goto error;
427
428 devres_close_group(dev, power_supply_add_hwmon_sysfs);
429 return 0;
430 error:
431 devres_release_group(dev, NULL);
432 return ret;
433 }
434
power_supply_remove_hwmon_sysfs(struct power_supply * psy)435 void power_supply_remove_hwmon_sysfs(struct power_supply *psy)
436 {
437 devres_release_group(&psy->dev, power_supply_add_hwmon_sysfs);
438 }
439