power_supply_hwmon.c

  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
 12struct power_supply_hwmon {
 13	struct power_supply *psy;
 14	unsigned long *props;
 15};
 16
 17static const char *const ps_temp_label[] = {
 18	"temp",
 19	"ambient temp",
 20};
 21
 22static 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
 38static 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
 52static 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
 64static 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
 97static int
 98power_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
115static 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
121struct hwmon_type_attr_list {
122	const u32 *attrs;
123	size_t n_attrs;
124};
125
126static 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
132static const struct hwmon_type_attr_list ps_type_attrs[hwmon_max] = {
133	[hwmon_temp] = { ps_temp_attrs, ARRAY_SIZE(ps_temp_attrs) },
134};
135
136static 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
154static 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
173static 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
198static 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
220static int
221power_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
269static int
270power_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
309static 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
316static 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
347static const struct hwmon_chip_info power_supply_hwmon_chip_info = {
348	.ops = &power_supply_hwmon_ops,
349	.info = power_supply_hwmon_info,
350};
351
352static const enum power_supply_property power_supply_hwmon_props[] = {
353	POWER_SUPPLY_PROP_CURRENT_AVG,
354	POWER_SUPPLY_PROP_CURRENT_MAX,
355	POWER_SUPPLY_PROP_CURRENT_NOW,
356	POWER_SUPPLY_PROP_POWER_AVG,
357	POWER_SUPPLY_PROP_POWER_NOW,
358	POWER_SUPPLY_PROP_TEMP,
359	POWER_SUPPLY_PROP_TEMP_MAX,
360	POWER_SUPPLY_PROP_TEMP_MIN,
361	POWER_SUPPLY_PROP_TEMP_ALERT_MIN,
362	POWER_SUPPLY_PROP_TEMP_ALERT_MAX,
363	POWER_SUPPLY_PROP_TEMP_AMBIENT,
364	POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MIN,
365	POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MAX,
366	POWER_SUPPLY_PROP_VOLTAGE_AVG,
367	POWER_SUPPLY_PROP_VOLTAGE_MIN,
368	POWER_SUPPLY_PROP_VOLTAGE_MAX,
369	POWER_SUPPLY_PROP_VOLTAGE_NOW,
370};
371
372int power_supply_add_hwmon_sysfs(struct power_supply *psy)
373{
374	struct power_supply_hwmon *psyhw;
375	struct device *dev = &psy->dev;
376	struct device *hwmon;
377	int ret, i;
378	const char *name;
379
380	if (!devres_open_group(dev, power_supply_add_hwmon_sysfs,
381			       GFP_KERNEL))
382		return -ENOMEM;
383
384	psyhw = devm_kzalloc(dev, sizeof(*psyhw), GFP_KERNEL);
385	if (!psyhw) {
386		ret = -ENOMEM;
387		goto error;
388	}
389
390	psyhw->psy = psy;
391	psyhw->props = devm_bitmap_zalloc(dev,
392					  POWER_SUPPLY_PROP_TIME_TO_FULL_AVG + 1,
393					  GFP_KERNEL);
394	if (!psyhw->props) {
395		ret = -ENOMEM;
396		goto error;
397	}
398
399	for (i = 0; i < ARRAY_SIZE(power_supply_hwmon_props); i++) {
400		const enum power_supply_property prop = power_supply_hwmon_props[i];
401
402		if (power_supply_has_property(psy, prop))
403			set_bit(prop, psyhw->props);
404	}
405
406	name = psy->desc->name;
407	if (strchr(name, '-')) {
408		char *new_name;
409
410		new_name = devm_kstrdup(dev, name, GFP_KERNEL);
411		if (!new_name) {
412			ret = -ENOMEM;
413			goto error;
414		}
415		strreplace(new_name, '-', '_');
416		name = new_name;
417	}
418	hwmon = devm_hwmon_device_register_with_info(dev, name,
419						psyhw,
420						&power_supply_hwmon_chip_info,
421						NULL);
422	ret = PTR_ERR_OR_ZERO(hwmon);
423	if (ret)
424		goto error;
425
426	devres_close_group(dev, power_supply_add_hwmon_sysfs);
427	return 0;
428error:
429	devres_release_group(dev, NULL);
430	return ret;
431}
432
433void power_supply_remove_hwmon_sysfs(struct power_supply *psy)
434{
435	devres_release_group(&psy->dev, power_supply_add_hwmon_sysfs);
436}