aboutsummaryrefslogtreecommitdiff
path: root/drivers/hwmon/scmi-hwmon.c
blob: e192f0c6714654f4107f60a34f1e74a230455c8e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
// SPDX-License-Identifier: GPL-2.0
/*
 * System Control and Management Interface(SCMI) based hwmon sensor driver
 *
 * Copyright (C) 2018-2021 ARM Ltd.
 * Sudeep Holla <sudeep.holla@arm.com>
 */

#include <linux/hwmon.h>
#include <linux/module.h>
#include <linux/scmi_protocol.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/thermal.h>

static const struct scmi_sensor_proto_ops *sensor_ops;

struct scmi_sensors {
	const struct scmi_protocol_handle *ph;
	const struct scmi_sensor_info **info[hwmon_max];
};

struct scmi_thermal_sensor {
	const struct scmi_protocol_handle *ph;
	const struct scmi_sensor_info *info;
};

static inline u64 __pow10(u8 x)
{
	u64 r = 1;

	while (x--)
		r *= 10;

	return r;
}

static int scmi_hwmon_scale(const struct scmi_sensor_info *sensor, u64 *value)
{
	int scale = sensor->scale;
	u64 f;

	switch (sensor->type) {
	case TEMPERATURE_C:
	case VOLTAGE:
	case CURRENT:
		scale += 3;
		break;
	case POWER:
	case ENERGY:
		scale += 6;
		break;
	default:
		break;
	}

	if (scale == 0)
		return 0;

	if (abs(scale) > 19)
		return -E2BIG;

	f = __pow10(abs(scale));
	if (scale > 0)
		*value *= f;
	else
		*value = div64_u64(*value, f);

	return 0;
}

static int scmi_hwmon_read_scaled_value(const struct scmi_protocol_handle *ph,
					const struct scmi_sensor_info *sensor,
					long *val)
{
	int ret;
	u64 value;

	ret = sensor_ops->reading_get(ph, sensor->id, &value);
	if (ret)
		return ret;

	ret = scmi_hwmon_scale(sensor, &value);
	if (!ret)
		*val = value;

	return ret;
}

static int scmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
			   u32 attr, int channel, long *val)
{
	const struct scmi_sensor_info *sensor;
	struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev);

	sensor = *(scmi_sensors->info[type] + channel);

	return scmi_hwmon_read_scaled_value(scmi_sensors->ph, sensor, val);
}

static int
scmi_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,
		       u32 attr, int channel, const char **str)
{
	const struct scmi_sensor_info *sensor;
	struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev);

	sensor = *(scmi_sensors->info[type] + channel);
	*str = sensor->name;

	return 0;
}

static umode_t
scmi_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,
		      u32 attr, int channel)
{
	const struct scmi_sensor_info *sensor;
	const struct scmi_sensors *scmi_sensors = drvdata;

	sensor = *(scmi_sensors->info[type] + channel);
	if (sensor)
		return 0444;

	return 0;
}

static const struct hwmon_ops scmi_hwmon_ops = {
	.is_visible = scmi_hwmon_is_visible,
	.read = scmi_hwmon_read,
	.read_string = scmi_hwmon_read_string,
};

static struct hwmon_chip_info scmi_chip_info = {
	.ops = &scmi_hwmon_ops,
	.info = NULL,
};

static int scmi_hwmon_thermal_get_temp(struct thermal_zone_device *tz,
				       int *temp)
{
	int ret;
	long value;
	struct scmi_thermal_sensor *th_sensor = tz->devdata;

	ret = scmi_hwmon_read_scaled_value(th_sensor->ph, th_sensor->info,
					   &value);
	if (!ret)
		*temp = value;

	return ret;
}

static const struct thermal_zone_device_ops scmi_hwmon_thermal_ops = {
	.get_temp = scmi_hwmon_thermal_get_temp,
};

static int scmi_hwmon_add_chan_info(struct hwmon_channel_info *scmi_hwmon_chan,
				    struct device *dev, int num,
				    enum hwmon_sensor_types type, u32 config)
{
	int i;
	u32 *cfg = devm_kcalloc(dev, num + 1, sizeof(*cfg), GFP_KERNEL);

	if (!cfg)
		return -ENOMEM;

	scmi_hwmon_chan->type = type;
	scmi_hwmon_chan->config = cfg;
	for (i = 0; i < num; i++, cfg++)
		*cfg = config;

	return 0;
}

static enum hwmon_sensor_types scmi_types[] = {
	[TEMPERATURE_C] = hwmon_temp,
	[VOLTAGE] = hwmon_in,
	[CURRENT] = hwmon_curr,
	[POWER] = hwmon_power,
	[ENERGY] = hwmon_energy,
};

static u32 hwmon_attributes[hwmon_max] = {
	[hwmon_temp] = HWMON_T_INPUT | HWMON_T_LABEL,
	[hwmon_in] = HWMON_I_INPUT | HWMON_I_LABEL,
	[hwmon_curr] = HWMON_C_INPUT | HWMON_C_LABEL,
	[hwmon_power] = HWMON_P_INPUT | HWMON_P_LABEL,
	[hwmon_energy] = HWMON_E_INPUT | HWMON_E_LABEL,
};

static int scmi_thermal_sensor_register(struct device *dev,
					const struct scmi_protocol_handle *ph,
					const struct scmi_sensor_info *sensor)
{
	struct scmi_thermal_sensor *th_sensor;
	struct thermal_zone_device *tzd;

	th_sensor = devm_kzalloc(dev, sizeof(*th_sensor), GFP_KERNEL);
	if (!th_sensor)
		return -ENOMEM;

	th_sensor->ph = ph;
	th_sensor->info = sensor;

	/*
	 * Try to register a temperature sensor with the Thermal Framework:
	 * skip sensors not defined as part of any thermal zone (-ENODEV) but
	 * report any other errors related to misconfigured zones/sensors.
	 */
	tzd = devm_thermal_of_zone_register(dev, th_sensor->info->id, th_sensor,
					    &scmi_hwmon_thermal_ops);
	if (IS_ERR(tzd)) {
		devm_kfree(dev, th_sensor);

		if (PTR_ERR(tzd) != -ENODEV)
			return PTR_ERR(tzd);

		dev_dbg(dev, "Sensor '%s' not attached to any thermal zone.\n",
			sensor->name);
	} else {
		dev_dbg(dev, "Sensor '%s' attached to thermal zone ID:%d\n",
			sensor->name, tzd->id);
	}

	return 0;
}

static int scmi_hwmon_probe(struct scmi_device *sdev)
{
	int i, idx;
	u16 nr_sensors;
	enum hwmon_sensor_types type;
	struct scmi_sensors *scmi_sensors;
	const struct scmi_sensor_info *sensor;
	int nr_count[hwmon_max] = {0}, nr_types = 0, nr_count_temp = 0;
	const struct hwmon_chip_info *chip_info;
	struct device *hwdev, *dev = &sdev->dev;
	struct hwmon_channel_info *scmi_hwmon_chan;
	const struct hwmon_channel_info **ptr_scmi_ci;
	const struct scmi_handle *handle = sdev->handle;
	struct scmi_protocol_handle *ph;

	if (!handle)
		return -ENODEV;

	sensor_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_SENSOR, &ph);
	if (IS_ERR(sensor_ops))
		return PTR_ERR(sensor_ops);

	nr_sensors = sensor_ops->count_get(ph);
	if (!nr_sensors)
		return -EIO;

	scmi_sensors = devm_kzalloc(dev, sizeof(*scmi_sensors), GFP_KERNEL);
	if (!scmi_sensors)
		return -ENOMEM;

	scmi_sensors->ph = ph;

	for (i = 0; i < nr_sensors; i++) {
		sensor = sensor_ops->info_get(ph, i);
		if (!sensor)
			return -EINVAL;

		switch (sensor->type) {
		case TEMPERATURE_C:
		case VOLTAGE:
		case CURRENT:
		case POWER:
		case ENERGY:
			type = scmi_types[sensor->type];
			if (!nr_count[type])
				nr_types++;
			nr_count[type]++;
			break;
		}
	}

	if (nr_count[hwmon_temp])
		nr_count_temp = nr_count[hwmon_temp];

	scmi_hwmon_chan = devm_kcalloc(dev, nr_types, sizeof(*scmi_hwmon_chan),
				       GFP_KERNEL);
	if (!scmi_hwmon_chan)
		return -ENOMEM;

	ptr_scmi_ci = devm_kcalloc(dev, nr_types + 1, sizeof(*ptr_scmi_ci),
				   GFP_KERNEL);
	if (!ptr_scmi_ci)
		return -ENOMEM;

	scmi_chip_info.info = ptr_scmi_ci;
	chip_info = &scmi_chip_info;

	for (type = 0; type < hwmon_max; type++) {
		if (!nr_count[type])
			continue;

		scmi_hwmon_add_chan_info(scmi_hwmon_chan, dev, nr_count[type],
					 type, hwmon_attributes[type]);
		*ptr_scmi_ci++ = scmi_hwmon_chan++;

		scmi_sensors->info[type] =
			devm_kcalloc(dev, nr_count[type],
				     sizeof(*scmi_sensors->info), GFP_KERNEL);
		if (!scmi_sensors->info[type])
			return -ENOMEM;
	}

	for (i = nr_sensors - 1; i >= 0 ; i--) {
		sensor = sensor_ops->info_get(ph, i);
		if (!sensor)
			continue;

		switch (sensor->type) {
		case TEMPERATURE_C:
		case VOLTAGE:
		case CURRENT:
		case POWER:
		case ENERGY:
			type = scmi_types[sensor->type];
			idx = --nr_count[type];
			*(scmi_sensors->info[type] + idx) = sensor;
			break;
		}
	}

	hwdev = devm_hwmon_device_register_with_info(dev, "scmi_sensors",
						     scmi_sensors, chip_info,
						     NULL);
	if (IS_ERR(hwdev))
		return PTR_ERR(hwdev);

	for (i = 0; i < nr_count_temp; i++) {
		int ret;

		sensor = *(scmi_sensors->info[hwmon_temp] + i);
		if (!sensor)
			continue;

		/*
		 * Warn on any misconfiguration related to thermal zones but
		 * bail out of probing only on memory errors.
		 */
		ret = scmi_thermal_sensor_register(dev, ph, sensor);
		if (ret) {
			if (ret == -ENOMEM)
				return ret;
			dev_warn(dev,
				 "Thermal zone misconfigured for %s. err=%d\n",
				 sensor->name, ret);
		}
	}

	return 0;
}

static const struct scmi_device_id scmi_id_table[] = {
	{ SCMI_PROTOCOL_SENSOR, "hwmon" },
	{ },
};
MODULE_DEVICE_TABLE(scmi, scmi_id_table);

static struct scmi_driver scmi_hwmon_drv = {
	.name		= "scmi-hwmon",
	.probe		= scmi_hwmon_probe,
	.id_table	= scmi_id_table,
};
module_scmi_driver(scmi_hwmon_drv);

MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
MODULE_DESCRIPTION("ARM SCMI HWMON interface driver");
MODULE_LICENSE("GPL v2");