summaryrefslogtreecommitdiff
path: root/drivers/hwmon/ibmpowernv.c
blob: 7c2c7be182f25df547af0316abbcb1b52e8258cd (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
/*
 * IBM PowerNV platform sensors for temperature/fan/voltage/power
 * Copyright (C) 2014 IBM
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.
 */

#define DRVNAME		"ibmpowernv"
#define pr_fmt(fmt)	DRVNAME ": " fmt

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/of.h>
#include <linux/slab.h>

#include <linux/platform_device.h>
#include <asm/opal.h>
#include <linux/err.h>

#define MAX_ATTR_LEN	32

/* Sensor suffix name from DT */
#define DT_FAULT_ATTR_SUFFIX		"faulted"
#define DT_DATA_ATTR_SUFFIX		"data"
#define DT_THRESHOLD_ATTR_SUFFIX	"thrs"

/*
 * Enumerates all the types of sensors in the POWERNV platform and does index
 * into 'struct sensor_group'
 */
enum sensors {
	FAN,
	AMBIENT_TEMP,
	POWER_SUPPLY,
	POWER_INPUT,
	MAX_SENSOR_TYPE,
};

static struct sensor_group {
	const char *name;
	const char *compatible;
	struct attribute_group group;
	u32 attr_count;
} sensor_groups[] = {
	{"fan", "ibm,opal-sensor-cooling-fan"},
	{"temp", "ibm,opal-sensor-amb-temp"},
	{"in", "ibm,opal-sensor-power-supply"},
	{"power", "ibm,opal-sensor-power"}
};

struct sensor_data {
	u32 id; /* An opaque id of the firmware for each sensor */
	enum sensors type;
	char name[MAX_ATTR_LEN];
	struct device_attribute dev_attr;
};

struct platform_data {
	const struct attribute_group *attr_groups[MAX_SENSOR_TYPE + 1];
	u32 sensors_count; /* Total count of sensors from each group */
};

static ssize_t show_sensor(struct device *dev, struct device_attribute *devattr,
			   char *buf)
{
	struct sensor_data *sdata = container_of(devattr, struct sensor_data,
						 dev_attr);
	ssize_t ret;
	u32 x;

	ret = opal_get_sensor_data(sdata->id, &x);
	if (ret)
		return ret;

	/* Convert temperature to milli-degrees */
	if (sdata->type == AMBIENT_TEMP)
		x *= 1000;
	/* Convert power to micro-watts */
	else if (sdata->type == POWER_INPUT)
		x *= 1000000;

	return sprintf(buf, "%u\n", x);
}

static int get_sensor_index_attr(const char *name, u32 *index,
					char *attr)
{
	char *hash_pos = strchr(name, '#');
	char buf[8] = { 0 };
	char *dash_pos;
	u32 copy_len;
	int err;

	if (!hash_pos)
		return -EINVAL;

	dash_pos = strchr(hash_pos, '-');
	if (!dash_pos)
		return -EINVAL;

	copy_len = dash_pos - hash_pos - 1;
	if (copy_len >= sizeof(buf))
		return -EINVAL;

	strncpy(buf, hash_pos + 1, copy_len);

	err = kstrtou32(buf, 10, index);
	if (err)
		return err;

	strncpy(attr, dash_pos + 1, MAX_ATTR_LEN);

	return 0;
}

/*
 * This function translates the DT node name into the 'hwmon' attribute name.
 * IBMPOWERNV device node appear like cooling-fan#2-data, amb-temp#1-thrs etc.
 * which need to be mapped as fan2_input, temp1_max respectively before
 * populating them inside hwmon device class.
 */
static int create_hwmon_attr_name(struct device *dev, enum sensors type,
					 const char *node_name,
					 char *hwmon_attr_name)
{
	char attr_suffix[MAX_ATTR_LEN];
	char *attr_name;
	u32 index;
	int err;

	err = get_sensor_index_attr(node_name, &index, attr_suffix);
	if (err) {
		dev_err(dev, "Sensor device node name '%s' is invalid\n",
			node_name);
		return err;
	}

	if (!strcmp(attr_suffix, DT_FAULT_ATTR_SUFFIX)) {
		attr_name = "fault";
	} else if (!strcmp(attr_suffix, DT_DATA_ATTR_SUFFIX)) {
		attr_name = "input";
	} else if (!strcmp(attr_suffix, DT_THRESHOLD_ATTR_SUFFIX)) {
		if (type == AMBIENT_TEMP)
			attr_name = "max";
		else if (type == FAN)
			attr_name = "min";
		else
			return -ENOENT;
	} else {
		return -ENOENT;
	}

	snprintf(hwmon_attr_name, MAX_ATTR_LEN, "%s%d_%s",
		 sensor_groups[type].name, index, attr_name);
	return 0;
}

static int populate_attr_groups(struct platform_device *pdev)
{
	struct platform_data *pdata = platform_get_drvdata(pdev);
	const struct attribute_group **pgroups = pdata->attr_groups;
	struct device_node *opal, *np;
	enum sensors type;

	opal = of_find_node_by_path("/ibm,opal/sensors");
	for_each_child_of_node(opal, np) {
		if (np->name == NULL)
			continue;

		for (type = 0; type < MAX_SENSOR_TYPE; type++)
			if (of_device_is_compatible(np,
					sensor_groups[type].compatible)) {
				sensor_groups[type].attr_count++;
				break;
			}
	}

	of_node_put(opal);

	for (type = 0; type < MAX_SENSOR_TYPE; type++) {
		sensor_groups[type].group.attrs = devm_kzalloc(&pdev->dev,
					sizeof(struct attribute *) *
					(sensor_groups[type].attr_count + 1),
					GFP_KERNEL);
		if (!sensor_groups[type].group.attrs)
			return -ENOMEM;

		pgroups[type] = &sensor_groups[type].group;
		pdata->sensors_count += sensor_groups[type].attr_count;
		sensor_groups[type].attr_count = 0;
	}

	return 0;
}

/*
 * Iterate through the device tree for each child of 'sensors' node, create
 * a sysfs attribute file, the file is named by translating the DT node name
 * to the name required by the higher 'hwmon' driver like fan1_input, temp1_max
 * etc..
 */
static int create_device_attrs(struct platform_device *pdev)
{
	struct platform_data *pdata = platform_get_drvdata(pdev);
	const struct attribute_group **pgroups = pdata->attr_groups;
	struct device_node *opal, *np;
	struct sensor_data *sdata;
	u32 sensor_id;
	enum sensors type;
	u32 count = 0;
	int err = 0;

	opal = of_find_node_by_path("/ibm,opal/sensors");
	sdata = devm_kzalloc(&pdev->dev, pdata->sensors_count * sizeof(*sdata),
			     GFP_KERNEL);
	if (!sdata) {
		err = -ENOMEM;
		goto exit_put_node;
	}

	for_each_child_of_node(opal, np) {
		if (np->name == NULL)
			continue;

		for (type = 0; type < MAX_SENSOR_TYPE; type++)
			if (of_device_is_compatible(np,
					sensor_groups[type].compatible))
				break;

		if (type == MAX_SENSOR_TYPE)
			continue;

		if (of_property_read_u32(np, "sensor-id", &sensor_id)) {
			dev_info(&pdev->dev,
				 "'sensor-id' missing in the node '%s'\n",
				 np->name);
			continue;
		}

		sdata[count].id = sensor_id;
		sdata[count].type = type;
		err = create_hwmon_attr_name(&pdev->dev, type, np->name,
					     sdata[count].name);
		if (err)
			goto exit_put_node;

		sysfs_attr_init(&sdata[count].dev_attr.attr);
		sdata[count].dev_attr.attr.name = sdata[count].name;
		sdata[count].dev_attr.attr.mode = S_IRUGO;
		sdata[count].dev_attr.show = show_sensor;

		pgroups[type]->attrs[sensor_groups[type].attr_count++] =
				&sdata[count++].dev_attr.attr;
	}

exit_put_node:
	of_node_put(opal);
	return err;
}

static int ibmpowernv_probe(struct platform_device *pdev)
{
	struct platform_data *pdata;
	struct device *hwmon_dev;
	int err;

	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
		return -ENOMEM;

	platform_set_drvdata(pdev, pdata);
	pdata->sensors_count = 0;
	err = populate_attr_groups(pdev);
	if (err)
		return err;

	/* Create sysfs attribute data for each sensor found in the DT */
	err = create_device_attrs(pdev);
	if (err)
		return err;

	/* Finally, register with hwmon */
	hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev, DRVNAME,
							   pdata,
							   pdata->attr_groups);

	return PTR_ERR_OR_ZERO(hwmon_dev);
}

static const struct platform_device_id opal_sensor_driver_ids[] = {
	{
		.name = "opal-sensor",
	},
	{ }
};
MODULE_DEVICE_TABLE(platform, opal_sensor_driver_ids);

static struct platform_driver ibmpowernv_driver = {
	.probe		= ibmpowernv_probe,
	.id_table	= opal_sensor_driver_ids,
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= DRVNAME,
	},
};

module_platform_driver(ibmpowernv_driver);

MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
MODULE_DESCRIPTION("IBM POWERNV platform sensors");
MODULE_LICENSE("GPL");