aboutsummaryrefslogtreecommitdiff
path: root/drivers/hwmon/scpi-hwmon.c
blob: a586480a7ca90a1c8d655324c04d0e6ccb3fde5c (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
/*
 * System Control and Power Interface(SCPI) based hwmon sensor driver
 *
 * Copyright (C) 2015 ARM Ltd.
 * Punit Agrawal <punit.agrawal@arm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

#include <linux/hwmon.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/scpi_protocol.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/thermal.h>

struct sensor_data {
	unsigned int scale;
	struct scpi_sensor_info info;
	struct device_attribute dev_attr_input;
	struct device_attribute dev_attr_label;
	char input[20];
	char label[20];
};

struct scpi_thermal_zone {
	int sensor_id;
	struct scpi_sensors *scpi_sensors;
};

struct scpi_sensors {
	struct scpi_ops *scpi_ops;
	struct sensor_data *data;
	struct list_head thermal_zones;
	struct attribute **attrs;
	struct attribute_group group;
	const struct attribute_group *groups[2];
};

static const u32 gxbb_scpi_scale[] = {
	[TEMPERATURE]	= 1,		/* (celsius)		*/
	[VOLTAGE]	= 1000,		/* (millivolts)		*/
	[CURRENT]	= 1000,		/* (milliamperes)	*/
	[POWER]		= 1000000,	/* (microwatts)		*/
	[ENERGY]	= 1000000,	/* (microjoules)	*/
};

static const u32 scpi_scale[] = {
	[TEMPERATURE]	= 1000,		/* (millicelsius)	*/
	[VOLTAGE]	= 1000,		/* (millivolts)		*/
	[CURRENT]	= 1000,		/* (milliamperes)	*/
	[POWER]		= 1000000,	/* (microwatts)		*/
	[ENERGY]	= 1000000,	/* (microjoules)	*/
};

static void scpi_scale_reading(u64 *value, struct sensor_data *sensor)
{
	if (scpi_scale[sensor->info.class] != sensor->scale) {
		*value *= scpi_scale[sensor->info.class];
		do_div(*value, sensor->scale);
	}
}

static int scpi_read_temp(void *dev, int *temp)
{
	struct scpi_thermal_zone *zone = dev;
	struct scpi_sensors *scpi_sensors = zone->scpi_sensors;
	struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
	struct sensor_data *sensor = &scpi_sensors->data[zone->sensor_id];
	u64 value;
	int ret;

	ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
	if (ret)
		return ret;

	scpi_scale_reading(&value, sensor);

	*temp = value;
	return 0;
}

/* hwmon callback functions */
static ssize_t
scpi_show_sensor(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct scpi_sensors *scpi_sensors = dev_get_drvdata(dev);
	struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
	struct sensor_data *sensor;
	u64 value;
	int ret;

	sensor = container_of(attr, struct sensor_data, dev_attr_input);

	ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
	if (ret)
		return ret;

	scpi_scale_reading(&value, sensor);

	return sprintf(buf, "%llu\n", value);
}

static ssize_t
scpi_show_label(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct sensor_data *sensor;

	sensor = container_of(attr, struct sensor_data, dev_attr_label);

	return sprintf(buf, "%s\n", sensor->info.name);
}

static struct thermal_zone_of_device_ops scpi_sensor_ops = {
	.get_temp = scpi_read_temp,
};

static const struct of_device_id scpi_of_match[] = {
	{.compatible = "arm,scpi-sensors", .data = &scpi_scale},
	{.compatible = "amlogic,meson-gxbb-scpi-sensors", .data = &gxbb_scpi_scale},
	{},
};
MODULE_DEVICE_TABLE(of, scpi_of_match);

static int scpi_hwmon_probe(struct platform_device *pdev)
{
	u16 nr_sensors, i;
	const u32 *scale;
	int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0;
	int num_energy = 0;
	struct scpi_ops *scpi_ops;
	struct device *hwdev, *dev = &pdev->dev;
	struct scpi_sensors *scpi_sensors;
	const struct of_device_id *of_id;
	int idx, ret;

	scpi_ops = get_scpi_ops();
	if (!scpi_ops)
		return -EPROBE_DEFER;

	ret = scpi_ops->sensor_get_capability(&nr_sensors);
	if (ret)
		return ret;

	if (!nr_sensors)
		return -ENODEV;

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

	scpi_sensors->data = devm_kcalloc(dev, nr_sensors,
				   sizeof(*scpi_sensors->data), GFP_KERNEL);
	if (!scpi_sensors->data)
		return -ENOMEM;

	scpi_sensors->attrs = devm_kcalloc(dev, (nr_sensors * 2) + 1,
				   sizeof(*scpi_sensors->attrs), GFP_KERNEL);
	if (!scpi_sensors->attrs)
		return -ENOMEM;

	scpi_sensors->scpi_ops = scpi_ops;

	of_id = of_match_device(scpi_of_match, &pdev->dev);
	if (!of_id) {
		dev_err(&pdev->dev, "Unable to initialize scpi-hwmon data\n");
		return -ENODEV;
	}
	scale = of_id->data;

	for (i = 0, idx = 0; i < nr_sensors; i++) {
		struct sensor_data *sensor = &scpi_sensors->data[idx];

		ret = scpi_ops->sensor_get_info(i, &sensor->info);
		if (ret)
			return ret;

		switch (sensor->info.class) {
		case TEMPERATURE:
			snprintf(sensor->input, sizeof(sensor->input),
				 "temp%d_input", num_temp + 1);
			snprintf(sensor->label, sizeof(sensor->input),
				 "temp%d_label", num_temp + 1);
			num_temp++;
			break;
		case VOLTAGE:
			snprintf(sensor->input, sizeof(sensor->input),
				 "in%d_input", num_volt);
			snprintf(sensor->label, sizeof(sensor->input),
				 "in%d_label", num_volt);
			num_volt++;
			break;
		case CURRENT:
			snprintf(sensor->input, sizeof(sensor->input),
				 "curr%d_input", num_current + 1);
			snprintf(sensor->label, sizeof(sensor->input),
				 "curr%d_label", num_current + 1);
			num_current++;
			break;
		case POWER:
			snprintf(sensor->input, sizeof(sensor->input),
				 "power%d_input", num_power + 1);
			snprintf(sensor->label, sizeof(sensor->input),
				 "power%d_label", num_power + 1);
			num_power++;
			break;
		case ENERGY:
			snprintf(sensor->input, sizeof(sensor->input),
				 "energy%d_input", num_energy + 1);
			snprintf(sensor->label, sizeof(sensor->input),
				 "energy%d_label", num_energy + 1);
			num_energy++;
			break;
		default:
			continue;
		}

		sensor->scale = scale[sensor->info.class];

		sensor->dev_attr_input.attr.mode = S_IRUGO;
		sensor->dev_attr_input.show = scpi_show_sensor;
		sensor->dev_attr_input.attr.name = sensor->input;

		sensor->dev_attr_label.attr.mode = S_IRUGO;
		sensor->dev_attr_label.show = scpi_show_label;
		sensor->dev_attr_label.attr.name = sensor->label;

		scpi_sensors->attrs[idx << 1] = &sensor->dev_attr_input.attr;
		scpi_sensors->attrs[(idx << 1) + 1] = &sensor->dev_attr_label.attr;

		sysfs_attr_init(scpi_sensors->attrs[idx << 1]);
		sysfs_attr_init(scpi_sensors->attrs[(idx << 1) + 1]);
		idx++;
	}

	scpi_sensors->group.attrs = scpi_sensors->attrs;
	scpi_sensors->groups[0] = &scpi_sensors->group;

	platform_set_drvdata(pdev, scpi_sensors);

	hwdev = devm_hwmon_device_register_with_groups(dev,
			"scpi_sensors", scpi_sensors, scpi_sensors->groups);

	if (IS_ERR(hwdev))
		return PTR_ERR(hwdev);

	/*
	 * Register the temperature sensors with the thermal framework
	 * to allow their usage in setting up the thermal zones from
	 * device tree.
	 *
	 * NOTE: Not all temperature sensors maybe used for thermal
	 * control
	 */
	INIT_LIST_HEAD(&scpi_sensors->thermal_zones);
	for (i = 0; i < nr_sensors; i++) {
		struct sensor_data *sensor = &scpi_sensors->data[i];
		struct thermal_zone_device *z;
		struct scpi_thermal_zone *zone;

		if (sensor->info.class != TEMPERATURE)
			continue;

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

		zone->sensor_id = i;
		zone->scpi_sensors = scpi_sensors;
		z = devm_thermal_zone_of_sensor_register(dev,
							 sensor->info.sensor_id,
							 zone,
							 &scpi_sensor_ops);
		/*
		 * The call to thermal_zone_of_sensor_register returns
		 * an error for sensors that are not associated with
		 * any thermal zones or if the thermal subsystem is
		 * not configured.
		 */
		if (IS_ERR(z)) {
			devm_kfree(dev, zone);
			continue;
		}
	}

	return 0;
}

static struct platform_driver scpi_hwmon_platdrv = {
	.driver = {
		.name	= "scpi-hwmon",
		.of_match_table = scpi_of_match,
	},
	.probe		= scpi_hwmon_probe,
};
module_platform_driver(scpi_hwmon_platdrv);

MODULE_AUTHOR("Punit Agrawal <punit.agrawal@arm.com>");
MODULE_DESCRIPTION("ARM SCPI HWMON interface driver");
MODULE_LICENSE("GPL v2");