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
11struct power_supply_hwmon {
12	struct power_supply *psy;
13	unsigned long *props;
14};
15
16static const char *const ps_temp_label[] = {
17	"temp",
18	"ambient temp",
19};
20
21static 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
37static 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
51static 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
84static int
85power_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
100static 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
106struct hwmon_type_attr_list {
107	const u32 *attrs;
108	size_t n_attrs;
109};
110
111static 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
117static const struct hwmon_type_attr_list ps_type_attrs[hwmon_max] = {
118	[hwmon_temp] = { ps_temp_attrs, ARRAY_SIZE(ps_temp_attrs) },
119};
120
121static 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
139static 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
158static 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
183static 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
205static int
206power_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
249static int
250power_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
289static 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
296static const struct hwmon_channel_info * const 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
322static const struct hwmon_chip_info power_supply_hwmon_chip_info = {
323	.ops = &power_supply_hwmon_ops,
324	.info = power_supply_hwmon_info,
325};
326
327int power_supply_add_hwmon_sysfs(struct power_supply *psy)
328{
329	const struct power_supply_desc *desc = psy->desc;
330	struct power_supply_hwmon *psyhw;
331	struct device *dev = &psy->dev;
332	struct device *hwmon;
333	int ret, i;
334	const char *name;
335
336	if (!devres_open_group(dev, power_supply_add_hwmon_sysfs,
337			       GFP_KERNEL))
338		return -ENOMEM;
339
340	psyhw = devm_kzalloc(dev, sizeof(*psyhw), GFP_KERNEL);
341	if (!psyhw) {
342		ret = -ENOMEM;
343		goto error;
344	}
345
346	psyhw->psy = psy;
347	psyhw->props = devm_bitmap_zalloc(dev,
348					  POWER_SUPPLY_PROP_TIME_TO_FULL_AVG + 1,
349					  GFP_KERNEL);
350	if (!psyhw->props) {
351		ret = -ENOMEM;
352		goto error;
353	}
354
355	for (i = 0; i < desc->num_properties; i++) {
356		const enum power_supply_property prop = desc->properties[i];
357
358		switch (prop) {
359		case POWER_SUPPLY_PROP_CURRENT_AVG:
360		case POWER_SUPPLY_PROP_CURRENT_MAX:
361		case POWER_SUPPLY_PROP_CURRENT_NOW:
362		case POWER_SUPPLY_PROP_TEMP:
363		case POWER_SUPPLY_PROP_TEMP_MAX:
364		case POWER_SUPPLY_PROP_TEMP_MIN:
365		case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
366		case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
367		case POWER_SUPPLY_PROP_TEMP_AMBIENT:
368		case POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MIN:
369		case POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MAX:
370		case POWER_SUPPLY_PROP_VOLTAGE_AVG:
371		case POWER_SUPPLY_PROP_VOLTAGE_MIN:
372		case POWER_SUPPLY_PROP_VOLTAGE_MAX:
373		case POWER_SUPPLY_PROP_VOLTAGE_NOW:
374			set_bit(prop, psyhw->props);
375			break;
376		default:
377			break;
378		}
379	}
380
381	name = psy->desc->name;
382	if (strchr(name, '-')) {
383		char *new_name;
384
385		new_name = devm_kstrdup(dev, name, GFP_KERNEL);
386		if (!new_name) {
387			ret = -ENOMEM;
388			goto error;
389		}
390		strreplace(new_name, '-', '_');
391		name = new_name;
392	}
393	hwmon = devm_hwmon_device_register_with_info(dev, name,
394						psyhw,
395						&power_supply_hwmon_chip_info,
396						NULL);
397	ret = PTR_ERR_OR_ZERO(hwmon);
398	if (ret)
399		goto error;
400
401	devres_close_group(dev, power_supply_add_hwmon_sysfs);
402	return 0;
403error:
404	devres_release_group(dev, NULL);
405	return ret;
406}
407
408void power_supply_remove_hwmon_sysfs(struct power_supply *psy)
409{
410	devres_release_group(&psy->dev, power_supply_add_hwmon_sysfs);
411}
412