[go: nahoru, domu]
1/*
2 * IBM PowerNV platform sensors for temperature/fan/voltage/power
3 * Copyright (C) 2014 IBM
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program.
17 */
18
19#define DRVNAME		"ibmpowernv"
20#define pr_fmt(fmt)	DRVNAME ": " fmt
21
22#include <linux/init.h>
23#include <linux/module.h>
24#include <linux/kernel.h>
25#include <linux/hwmon.h>
26#include <linux/hwmon-sysfs.h>
27#include <linux/of.h>
28#include <linux/slab.h>
29
30#include <linux/platform_device.h>
31#include <asm/opal.h>
32#include <linux/err.h>
33
34#define MAX_ATTR_LEN	32
35
36/* Sensor suffix name from DT */
37#define DT_FAULT_ATTR_SUFFIX		"faulted"
38#define DT_DATA_ATTR_SUFFIX		"data"
39#define DT_THRESHOLD_ATTR_SUFFIX	"thrs"
40
41/*
42 * Enumerates all the types of sensors in the POWERNV platform and does index
43 * into 'struct sensor_group'
44 */
45enum sensors {
46	FAN,
47	AMBIENT_TEMP,
48	POWER_SUPPLY,
49	POWER_INPUT,
50	MAX_SENSOR_TYPE,
51};
52
53static struct sensor_group {
54	const char *name;
55	const char *compatible;
56	struct attribute_group group;
57	u32 attr_count;
58} sensor_groups[] = {
59	{"fan", "ibm,opal-sensor-cooling-fan"},
60	{"temp", "ibm,opal-sensor-amb-temp"},
61	{"in", "ibm,opal-sensor-power-supply"},
62	{"power", "ibm,opal-sensor-power"}
63};
64
65struct sensor_data {
66	u32 id; /* An opaque id of the firmware for each sensor */
67	enum sensors type;
68	char name[MAX_ATTR_LEN];
69	struct device_attribute dev_attr;
70};
71
72struct platform_data {
73	const struct attribute_group *attr_groups[MAX_SENSOR_TYPE + 1];
74	u32 sensors_count; /* Total count of sensors from each group */
75};
76
77/* Platform device representing all the ibmpowernv sensors */
78static struct platform_device *pdevice;
79
80static ssize_t show_sensor(struct device *dev, struct device_attribute *devattr,
81			   char *buf)
82{
83	struct sensor_data *sdata = container_of(devattr, struct sensor_data,
84						 dev_attr);
85	ssize_t ret;
86	u32 x;
87
88	ret = opal_get_sensor_data(sdata->id, &x);
89	if (ret)
90		return ret;
91
92	/* Convert temperature to milli-degrees */
93	if (sdata->type == AMBIENT_TEMP)
94		x *= 1000;
95	/* Convert power to micro-watts */
96	else if (sdata->type == POWER_INPUT)
97		x *= 1000000;
98
99	return sprintf(buf, "%u\n", x);
100}
101
102static int __init get_sensor_index_attr(const char *name, u32 *index,
103					char *attr)
104{
105	char *hash_pos = strchr(name, '#');
106	char buf[8] = { 0 };
107	char *dash_pos;
108	u32 copy_len;
109	int err;
110
111	if (!hash_pos)
112		return -EINVAL;
113
114	dash_pos = strchr(hash_pos, '-');
115	if (!dash_pos)
116		return -EINVAL;
117
118	copy_len = dash_pos - hash_pos - 1;
119	if (copy_len >= sizeof(buf))
120		return -EINVAL;
121
122	strncpy(buf, hash_pos + 1, copy_len);
123
124	err = kstrtou32(buf, 10, index);
125	if (err)
126		return err;
127
128	strncpy(attr, dash_pos + 1, MAX_ATTR_LEN);
129
130	return 0;
131}
132
133/*
134 * This function translates the DT node name into the 'hwmon' attribute name.
135 * IBMPOWERNV device node appear like cooling-fan#2-data, amb-temp#1-thrs etc.
136 * which need to be mapped as fan2_input, temp1_max respectively before
137 * populating them inside hwmon device class.
138 */
139static int __init create_hwmon_attr_name(struct device *dev, enum sensors type,
140					 const char *node_name,
141					 char *hwmon_attr_name)
142{
143	char attr_suffix[MAX_ATTR_LEN];
144	char *attr_name;
145	u32 index;
146	int err;
147
148	err = get_sensor_index_attr(node_name, &index, attr_suffix);
149	if (err) {
150		dev_err(dev, "Sensor device node name '%s' is invalid\n",
151			node_name);
152		return err;
153	}
154
155	if (!strcmp(attr_suffix, DT_FAULT_ATTR_SUFFIX)) {
156		attr_name = "fault";
157	} else if (!strcmp(attr_suffix, DT_DATA_ATTR_SUFFIX)) {
158		attr_name = "input";
159	} else if (!strcmp(attr_suffix, DT_THRESHOLD_ATTR_SUFFIX)) {
160		if (type == AMBIENT_TEMP)
161			attr_name = "max";
162		else if (type == FAN)
163			attr_name = "min";
164		else
165			return -ENOENT;
166	} else {
167		return -ENOENT;
168	}
169
170	snprintf(hwmon_attr_name, MAX_ATTR_LEN, "%s%d_%s",
171		 sensor_groups[type].name, index, attr_name);
172	return 0;
173}
174
175static int __init populate_attr_groups(struct platform_device *pdev)
176{
177	struct platform_data *pdata = platform_get_drvdata(pdev);
178	const struct attribute_group **pgroups = pdata->attr_groups;
179	struct device_node *opal, *np;
180	enum sensors type;
181
182	opal = of_find_node_by_path("/ibm,opal/sensors");
183	if (!opal) {
184		dev_dbg(&pdev->dev, "Opal node 'sensors' not found\n");
185		return -ENODEV;
186	}
187
188	for_each_child_of_node(opal, np) {
189		if (np->name == NULL)
190			continue;
191
192		for (type = 0; type < MAX_SENSOR_TYPE; type++)
193			if (of_device_is_compatible(np,
194					sensor_groups[type].compatible)) {
195				sensor_groups[type].attr_count++;
196				break;
197			}
198	}
199
200	of_node_put(opal);
201
202	for (type = 0; type < MAX_SENSOR_TYPE; type++) {
203		sensor_groups[type].group.attrs = devm_kzalloc(&pdev->dev,
204					sizeof(struct attribute *) *
205					(sensor_groups[type].attr_count + 1),
206					GFP_KERNEL);
207		if (!sensor_groups[type].group.attrs)
208			return -ENOMEM;
209
210		pgroups[type] = &sensor_groups[type].group;
211		pdata->sensors_count += sensor_groups[type].attr_count;
212		sensor_groups[type].attr_count = 0;
213	}
214
215	return 0;
216}
217
218/*
219 * Iterate through the device tree for each child of 'sensors' node, create
220 * a sysfs attribute file, the file is named by translating the DT node name
221 * to the name required by the higher 'hwmon' driver like fan1_input, temp1_max
222 * etc..
223 */
224static int __init create_device_attrs(struct platform_device *pdev)
225{
226	struct platform_data *pdata = platform_get_drvdata(pdev);
227	const struct attribute_group **pgroups = pdata->attr_groups;
228	struct device_node *opal, *np;
229	struct sensor_data *sdata;
230	u32 sensor_id;
231	enum sensors type;
232	u32 count = 0;
233	int err = 0;
234
235	opal = of_find_node_by_path("/ibm,opal/sensors");
236	sdata = devm_kzalloc(&pdev->dev, pdata->sensors_count * sizeof(*sdata),
237			     GFP_KERNEL);
238	if (!sdata) {
239		err = -ENOMEM;
240		goto exit_put_node;
241	}
242
243	for_each_child_of_node(opal, np) {
244		if (np->name == NULL)
245			continue;
246
247		for (type = 0; type < MAX_SENSOR_TYPE; type++)
248			if (of_device_is_compatible(np,
249					sensor_groups[type].compatible))
250				break;
251
252		if (type == MAX_SENSOR_TYPE)
253			continue;
254
255		if (of_property_read_u32(np, "sensor-id", &sensor_id)) {
256			dev_info(&pdev->dev,
257				 "'sensor-id' missing in the node '%s'\n",
258				 np->name);
259			continue;
260		}
261
262		sdata[count].id = sensor_id;
263		sdata[count].type = type;
264		err = create_hwmon_attr_name(&pdev->dev, type, np->name,
265					     sdata[count].name);
266		if (err)
267			goto exit_put_node;
268
269		sysfs_attr_init(&sdata[count].dev_attr.attr);
270		sdata[count].dev_attr.attr.name = sdata[count].name;
271		sdata[count].dev_attr.attr.mode = S_IRUGO;
272		sdata[count].dev_attr.show = show_sensor;
273
274		pgroups[type]->attrs[sensor_groups[type].attr_count++] =
275				&sdata[count++].dev_attr.attr;
276	}
277
278exit_put_node:
279	of_node_put(opal);
280	return err;
281}
282
283static int __init ibmpowernv_probe(struct platform_device *pdev)
284{
285	struct platform_data *pdata;
286	struct device *hwmon_dev;
287	int err;
288
289	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
290	if (!pdata)
291		return -ENOMEM;
292
293	platform_set_drvdata(pdev, pdata);
294	pdata->sensors_count = 0;
295	err = populate_attr_groups(pdev);
296	if (err)
297		return err;
298
299	/* Create sysfs attribute data for each sensor found in the DT */
300	err = create_device_attrs(pdev);
301	if (err)
302		return err;
303
304	/* Finally, register with hwmon */
305	hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev, DRVNAME,
306							   pdata,
307							   pdata->attr_groups);
308
309	return PTR_ERR_OR_ZERO(hwmon_dev);
310}
311
312static struct platform_driver ibmpowernv_driver = {
313	.driver = {
314		.owner = THIS_MODULE,
315		.name = DRVNAME,
316	},
317};
318
319static int __init ibmpowernv_init(void)
320{
321	int err;
322
323	pdevice = platform_device_alloc(DRVNAME, 0);
324	if (!pdevice) {
325		pr_err("Device allocation failed\n");
326		err = -ENOMEM;
327		goto exit;
328	}
329
330	err = platform_device_add(pdevice);
331	if (err) {
332		pr_err("Device addition failed (%d)\n", err);
333		goto exit_device_put;
334	}
335
336	err = platform_driver_probe(&ibmpowernv_driver, ibmpowernv_probe);
337	if (err) {
338		if (err != -ENODEV)
339			pr_err("Platform driver probe failed (%d)\n", err);
340
341		goto exit_device_del;
342	}
343
344	return 0;
345
346exit_device_del:
347	platform_device_del(pdevice);
348exit_device_put:
349	platform_device_put(pdevice);
350exit:
351	return err;
352}
353
354static void __exit ibmpowernv_exit(void)
355{
356	platform_driver_unregister(&ibmpowernv_driver);
357	platform_device_unregister(pdevice);
358}
359
360MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
361MODULE_DESCRIPTION("IBM POWERNV platform sensors");
362MODULE_LICENSE("GPL");
363
364module_init(ibmpowernv_init);
365module_exit(ibmpowernv_exit);
366