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