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 */
45 enum sensors {
46 FAN,
47 AMBIENT_TEMP,
48 POWER_SUPPLY,
49 POWER_INPUT,
50 MAX_SENSOR_TYPE,
51 };
52
53 static 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
65 struct 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
72 struct 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 */
78 static struct platform_device *pdevice;
79
show_sensor(struct device * dev,struct device_attribute * devattr,char * buf)80 static 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
get_sensor_index_attr(const char * name,u32 * index,char * attr)102 static 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 */
create_hwmon_attr_name(struct device * dev,enum sensors type,const char * node_name,char * hwmon_attr_name)139 static 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
populate_attr_groups(struct platform_device * pdev)175 static 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 */
create_device_attrs(struct platform_device * pdev)224 static 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
278 exit_put_node:
279 of_node_put(opal);
280 return err;
281 }
282
ibmpowernv_probe(struct platform_device * pdev)283 static 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
312 static struct platform_driver ibmpowernv_driver = {
313 .driver = {
314 .owner = THIS_MODULE,
315 .name = DRVNAME,
316 },
317 };
318
ibmpowernv_init(void)319 static 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
346 exit_device_del:
347 platform_device_del(pdevice);
348 exit_device_put:
349 platform_device_put(pdevice);
350 exit:
351 return err;
352 }
353
ibmpowernv_exit(void)354 static void __exit ibmpowernv_exit(void)
355 {
356 platform_driver_unregister(&ibmpowernv_driver);
357 platform_device_unregister(pdevice);
358 }
359
360 MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
361 MODULE_DESCRIPTION("IBM POWERNV platform sensors");
362 MODULE_LICENSE("GPL");
363
364 module_init(ibmpowernv_init);
365 module_exit(ibmpowernv_exit);
366