drivers/hwmon/ibmpowernv.c

   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 #define MAX_LABEL_LEN   64
  36
  37 /* Sensor suffix name from DT */
  38 #define DT_FAULT_ATTR_SUFFIX            "faulted"
  39 #define DT_DATA_ATTR_SUFFIX             "data"
  40 #define DT_THRESHOLD_ATTR_SUFFIX        "thrs"
  41
  42 /*
  43  * Enumerates all the types of sensors in the POWERNV platform and does index
  44  * into 'struct sensor_group'
  45  */
  46 enum sensors {
  47         FAN,
  48         TEMP,
  49         POWER_SUPPLY,
  50         POWER_INPUT,
  51         MAX_SENSOR_TYPE,
  52 };
  53
  54 #define INVALID_INDEX (-1U)
  55
  56 static struct sensor_group {
  57         const char *name;
  58         const char *compatible;
  59         struct attribute_group group;
  60         u32 attr_count;
  61         u32 hwmon_index;
  62 } sensor_groups[] = {
  63         {"fan", "ibm,opal-sensor-cooling-fan"},
  64         {"temp", "ibm,opal-sensor-amb-temp"},
  65         {"in", "ibm,opal-sensor-power-supply"},
  66         {"power", "ibm,opal-sensor-power"}
  67 };
  68
  69 struct sensor_data {
  70         u32 id; /* An opaque id of the firmware for each sensor */
  71         u32 hwmon_index;
  72         u32 opal_index;
  73         enum sensors type;
  74         char label[MAX_LABEL_LEN];
  75         char name[MAX_ATTR_LEN];
  76         struct device_attribute dev_attr;
  77 };
  78
  79 struct platform_data {
  80         const struct attribute_group *attr_groups[MAX_SENSOR_TYPE + 1];
  81         u32 sensors_count; /* Total count of sensors from each group */
  82 };
  83
  84 static ssize_t show_sensor(struct device *dev, struct device_attribute *devattr,
  85                            char *buf)
  86 {
  87         struct sensor_data *sdata = container_of(devattr, struct sensor_data,
  88                                                  dev_attr);
  89         ssize_t ret;
  90         u32 x;
  91
  92         ret = opal_get_sensor_data(sdata->id, &x);
  93         if (ret)
  94                 return ret;
  95
  96         /* Convert temperature to milli-degrees */
  97         if (sdata->type == TEMP)
  98                 x *= 1000;
  99         /* Convert power to micro-watts */
 100         else if (sdata->type == POWER_INPUT)
 101                 x *= 1000000;
 102
 103         return sprintf(buf, "%u\n", x);
 104 }
 105
 106 static ssize_t show_label(struct device *dev, struct device_attribute *devattr,
 107                           char *buf)
 108 {
 109         struct sensor_data *sdata = container_of(devattr, struct sensor_data,
 110                                                  dev_attr);
 111
 112         return sprintf(buf, "%s\n", sdata->label);
 113 }
 114
 115 static void __init make_sensor_label(struct device_node *np,
 116                                      struct sensor_data *sdata,
 117                                      const char *label)
 118 {
 119         size_t n;
 120
 121         n = snprintf(sdata->label, sizeof(sdata->label), "%s", label);
 122 }
 123
 124 static int get_sensor_index_attr(const char *name, u32 *index, char *attr)
 125 {
 126         char *hash_pos = strchr(name, '#');
 127         char buf[8] = { 0 };
 128         char *dash_pos;
 129         u32 copy_len;
 130         int err;
 131
 132         if (!hash_pos)
 133                 return -EINVAL;
 134
 135         dash_pos = strchr(hash_pos, '-');
 136         if (!dash_pos)
 137                 return -EINVAL;
 138
 139         copy_len = dash_pos - hash_pos - 1;
 140         if (copy_len >= sizeof(buf))
 141                 return -EINVAL;
 142
 143         strncpy(buf, hash_pos + 1, copy_len);
 144
 145         err = kstrtou32(buf, 10, index);
 146         if (err)
 147                 return err;
 148
 149         strncpy(attr, dash_pos + 1, MAX_ATTR_LEN);
 150
 151         return 0;
 152 }
 153
 154 static const char *convert_opal_attr_name(enum sensors type,
 155                                           const char *opal_attr)
 156 {
 157         const char *attr_name = NULL;
 158
 159         if (!strcmp(opal_attr, DT_FAULT_ATTR_SUFFIX)) {
 160                 attr_name = "fault";
 161         } else if (!strcmp(opal_attr, DT_DATA_ATTR_SUFFIX)) {
 162                 attr_name = "input";
 163         } else if (!strcmp(opal_attr, DT_THRESHOLD_ATTR_SUFFIX)) {
 164                 if (type == TEMP)
 165                         attr_name = "max";
 166                 else if (type == FAN)
 167                         attr_name = "min";
 168         }
 169
 170         return attr_name;
 171 }
 172
 173 /*
 174  * This function translates the DT node name into the 'hwmon' attribute name.
 175  * IBMPOWERNV device node appear like cooling-fan#2-data, amb-temp#1-thrs etc.
 176  * which need to be mapped as fan2_input, temp1_max respectively before
 177  * populating them inside hwmon device class.
 178  */
 179 static const char *parse_opal_node_name(const char *node_name,
 180                                         enum sensors type, u32 *index)
 181 {
 182         char attr_suffix[MAX_ATTR_LEN];
 183         const char *attr_name;
 184         int err;
 185
 186         err = get_sensor_index_attr(node_name, index, attr_suffix);
 187         if (err)
 188                 return ERR_PTR(err);
 189
 190         attr_name = convert_opal_attr_name(type, attr_suffix);
 191         if (!attr_name)
 192                 return ERR_PTR(-ENOENT);
 193
 194         return attr_name;
 195 }
 196
 197 static int get_sensor_type(struct device_node *np)
 198 {
 199         enum sensors type;
 200         const char *str;
 201
 202         for (type = 0; type < MAX_SENSOR_TYPE; type++) {
 203                 if (of_device_is_compatible(np, sensor_groups[type].compatible))
 204                         return type;
 205         }
 206
 207         /*
 208          * Let's check if we have a newer device tree
 209          */
 210         if (!of_device_is_compatible(np, "ibm,opal-sensor"))
 211                 return MAX_SENSOR_TYPE;
 212
 213         if (of_property_read_string(np, "sensor-type", &str))
 214                 return MAX_SENSOR_TYPE;
 215
 216         for (type = 0; type < MAX_SENSOR_TYPE; type++)
 217                 if (!strcmp(str, sensor_groups[type].name))
 218                         return type;
 219
 220         return MAX_SENSOR_TYPE;
 221 }
 222
 223 static u32 get_sensor_hwmon_index(struct sensor_data *sdata,
 224                                   struct sensor_data *sdata_table, int count)
 225 {
 226         int i;
 227
 228         /*
 229          * We don't use the OPAL index on newer device trees
 230          */
 231         if (sdata->opal_index != INVALID_INDEX) {
 232                 for (i = 0; i < count; i++)
 233                         if (sdata_table[i].opal_index == sdata->opal_index &&
 234                             sdata_table[i].type == sdata->type)
 235                                 return sdata_table[i].hwmon_index;
 236         }
 237         return ++sensor_groups[sdata->type].hwmon_index;
 238 }
 239
 240 static int populate_attr_groups(struct platform_device *pdev)
 241 {
 242         struct platform_data *pdata = platform_get_drvdata(pdev);
 243         const struct attribute_group **pgroups = pdata->attr_groups;
 244         struct device_node *opal, *np;
 245         enum sensors type;
 246
 247         opal = of_find_node_by_path("/ibm,opal/sensors");
 248         for_each_child_of_node(opal, np) {
 249                 const char *label;
 250
 251                 if (np->name == NULL)
 252                         continue;
 253
 254                 type = get_sensor_type(np);
 255                 if (type == MAX_SENSOR_TYPE)
 256                         continue;
 257
 258                 sensor_groups[type].attr_count++;
 259
 260                 /*
 261                  * add a new attribute for labels
 262                  */
 263                 if (!of_property_read_string(np, "label", &label))
 264                         sensor_groups[type].attr_count++;
 265         }
 266
 267         of_node_put(opal);
 268
 269         for (type = 0; type < MAX_SENSOR_TYPE; type++) {
 270                 sensor_groups[type].group.attrs = devm_kzalloc(&pdev->dev,
 271                                         sizeof(struct attribute *) *
 272                                         (sensor_groups[type].attr_count + 1),
 273                                         GFP_KERNEL);
 274                 if (!sensor_groups[type].group.attrs)
 275                         return -ENOMEM;
 276
 277                 pgroups[type] = &sensor_groups[type].group;
 278                 pdata->sensors_count += sensor_groups[type].attr_count;
 279                 sensor_groups[type].attr_count = 0;
 280         }
 281
 282         return 0;
 283 }
 284
 285 static void create_hwmon_attr(struct sensor_data *sdata, const char *attr_name,
 286                               ssize_t (*show)(struct device *dev,
 287                                               struct device_attribute *attr,
 288                                               char *buf))
 289 {
 290         snprintf(sdata->name, MAX_ATTR_LEN, "%s%d_%s",
 291                  sensor_groups[sdata->type].name, sdata->hwmon_index,
 292                  attr_name);
 293
 294         sysfs_attr_init(&sdata->dev_attr.attr);
 295         sdata->dev_attr.attr.name = sdata->name;
 296         sdata->dev_attr.attr.mode = S_IRUGO;
 297         sdata->dev_attr.show = show;
 298 }
 299
 300 /*
 301  * Iterate through the device tree for each child of 'sensors' node, create
 302  * a sysfs attribute file, the file is named by translating the DT node name
 303  * to the name required by the higher 'hwmon' driver like fan1_input, temp1_max
 304  * etc..
 305  */
 306 static int create_device_attrs(struct platform_device *pdev)
 307 {
 308         struct platform_data *pdata = platform_get_drvdata(pdev);
 309         const struct attribute_group **pgroups = pdata->attr_groups;
 310         struct device_node *opal, *np;
 311         struct sensor_data *sdata;
 312         u32 sensor_id;
 313         enum sensors type;
 314         u32 count = 0;
 315         int err = 0;
 316
 317         opal = of_find_node_by_path("/ibm,opal/sensors");
 318         sdata = devm_kzalloc(&pdev->dev, pdata->sensors_count * sizeof(*sdata),
 319                              GFP_KERNEL);
 320         if (!sdata) {
 321                 err = -ENOMEM;
 322                 goto exit_put_node;
 323         }
 324
 325         for_each_child_of_node(opal, np) {
 326                 const char *attr_name;
 327                 u32 opal_index;
 328                 const char *label;
 329
 330                 if (np->name == NULL)
 331                         continue;
 332
 333                 type = get_sensor_type(np);
 334                 if (type == MAX_SENSOR_TYPE)
 335                         continue;
 336
 337                 /*
 338                  * Newer device trees use a "sensor-data" property
 339                  * name for input.
 340                  */
 341                 if (of_property_read_u32(np, "sensor-id", &sensor_id) &&
 342                     of_property_read_u32(np, "sensor-data", &sensor_id)) {
 343                         dev_info(&pdev->dev,
 344                                  "'sensor-id' missing in the node '%s'\n",
 345                                  np->name);
 346                         continue;
 347                 }
 348
 349                 sdata[count].id = sensor_id;
 350                 sdata[count].type = type;
 351
 352                 /*
 353                  * If we can not parse the node name, it means we are
 354                  * running on a newer device tree. We can just forget
 355                  * about the OPAL index and use a defaut value for the
 356                  * hwmon attribute name
 357                  */
 358                 attr_name = parse_opal_node_name(np->name, type, &opal_index);
 359                 if (IS_ERR(attr_name)) {
 360                         attr_name = "input";
 361                         opal_index = INVALID_INDEX;
 362                 }
 363
 364                 sdata[count].opal_index = opal_index;
 365                 sdata[count].hwmon_index =
 366                         get_sensor_hwmon_index(&sdata[count], sdata, count);
 367
 368                 create_hwmon_attr(&sdata[count], attr_name, show_sensor);
 369
 370                 pgroups[type]->attrs[sensor_groups[type].attr_count++] =
 371                                 &sdata[count++].dev_attr.attr;
 372
 373                 if (!of_property_read_string(np, "label", &label)) {
 374                         /*
 375                          * For the label attribute, we can reuse the
 376                          * "properties" of the previous "input"
 377                          * attribute. They are related to the same
 378                          * sensor.
 379                          */
 380                         sdata[count].type = type;
 381                         sdata[count].opal_index = sdata[count - 1].opal_index;
 382                         sdata[count].hwmon_index = sdata[count - 1].hwmon_index;
 383
 384                         make_sensor_label(np, &sdata[count], label);
 385
 386                         create_hwmon_attr(&sdata[count], "label", show_label);
 387
 388                         pgroups[type]->attrs[sensor_groups[type].attr_count++] =
 389                                 &sdata[count++].dev_attr.attr;
 390                 }
 391         }
 392
 393 exit_put_node:
 394         of_node_put(opal);
 395         return err;
 396 }
 397
 398 static int ibmpowernv_probe(struct platform_device *pdev)
 399 {
 400         struct platform_data *pdata;
 401         struct device *hwmon_dev;
 402         int err;
 403
 404         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 405         if (!pdata)
 406                 return -ENOMEM;
 407
 408         platform_set_drvdata(pdev, pdata);
 409         pdata->sensors_count = 0;
 410         err = populate_attr_groups(pdev);
 411         if (err)
 412                 return err;
 413
 414         /* Create sysfs attribute data for each sensor found in the DT */
 415         err = create_device_attrs(pdev);
 416         if (err)
 417                 return err;
 418
 419         /* Finally, register with hwmon */
 420         hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev, DRVNAME,
 421                                                            pdata,
 422                                                            pdata->attr_groups);
 423
 424         return PTR_ERR_OR_ZERO(hwmon_dev);
 425 }
 426
 427 static const struct platform_device_id opal_sensor_driver_ids[] = {
 428         {
 429                 .name = "opal-sensor",
 430         },
 431         { }
 432 };
 433 MODULE_DEVICE_TABLE(platform, opal_sensor_driver_ids);
 434
 435 static struct platform_driver ibmpowernv_driver = {
 436         .probe          = ibmpowernv_probe,
 437         .id_table       = opal_sensor_driver_ids,
 438         .driver         = {
 439                 .name   = DRVNAME,
 440         },
 441 };
 442
 443 module_platform_driver(ibmpowernv_driver);
 444
 445 MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
 446 MODULE_DESCRIPTION("IBM POWERNV platform sensors");
 447 MODULE_LICENSE("GPL");