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
  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         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         u32 hwmon_index;
  59 } sensor_groups[] = {
  60         {"fan", "ibm,opal-sensor-cooling-fan"},
  61         {"temp", "ibm,opal-sensor-amb-temp"},
  62         {"in", "ibm,opal-sensor-power-supply"},
  63         {"power", "ibm,opal-sensor-power"}
  64 };
  65
  66 struct sensor_data {
  67         u32 id; /* An opaque id of the firmware for each sensor */
  68         u32 hwmon_index;
  69         u32 opal_index;
  70         enum sensors type;
  71         char name[MAX_ATTR_LEN];
  72         struct device_attribute dev_attr;
  73 };
  74
  75 struct platform_data {
  76         const struct attribute_group *attr_groups[MAX_SENSOR_TYPE + 1];
  77         u32 sensors_count; /* Total count of sensors from each group */
  78 };
  79
  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 == 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
 102 static int 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 static const char *convert_opal_attr_name(enum sensors type,
 134                                           const char *opal_attr)
 135 {
 136         const char *attr_name = NULL;
 137
 138         if (!strcmp(opal_attr, DT_FAULT_ATTR_SUFFIX)) {
 139                 attr_name = "fault";
 140         } else if (!strcmp(opal_attr, DT_DATA_ATTR_SUFFIX)) {
 141                 attr_name = "input";
 142         } else if (!strcmp(opal_attr, DT_THRESHOLD_ATTR_SUFFIX)) {
 143                 if (type == TEMP)
 144                         attr_name = "max";
 145                 else if (type == FAN)
 146                         attr_name = "min";
 147         }
 148
 149         return attr_name;
 150 }
 151
 152 /*
 153  * This function translates the DT node name into the 'hwmon' attribute name.
 154  * IBMPOWERNV device node appear like cooling-fan#2-data, amb-temp#1-thrs etc.
 155  * which need to be mapped as fan2_input, temp1_max respectively before
 156  * populating them inside hwmon device class.
 157  */
 158 static const char *parse_opal_node_name(const char *node_name,
 159                                         enum sensors type, u32 *index)
 160 {
 161         char attr_suffix[MAX_ATTR_LEN];
 162         const char *attr_name;
 163         int err;
 164
 165         err = get_sensor_index_attr(node_name, index, attr_suffix);
 166         if (err)
 167                 return ERR_PTR(err);
 168
 169         attr_name = convert_opal_attr_name(type, attr_suffix);
 170         if (!attr_name)
 171                 return ERR_PTR(-ENOENT);
 172
 173         return attr_name;
 174 }
 175
 176 static int get_sensor_type(struct device_node *np)
 177 {
 178         enum sensors type;
 179
 180         for (type = 0; type < MAX_SENSOR_TYPE; type++) {
 181                 if (of_device_is_compatible(np, sensor_groups[type].compatible))
 182                         return type;
 183         }
 184         return MAX_SENSOR_TYPE;
 185 }
 186
 187 static u32 get_sensor_hwmon_index(struct sensor_data *sdata,
 188                                   struct sensor_data *sdata_table, int count)
 189 {
 190         int i;
 191
 192         for (i = 0; i < count; i++)
 193                 if (sdata_table[i].opal_index == sdata->opal_index &&
 194                     sdata_table[i].type == sdata->type)
 195                         return sdata_table[i].hwmon_index;
 196
 197         return ++sensor_groups[sdata->type].hwmon_index;
 198 }
 199
 200 static int populate_attr_groups(struct platform_device *pdev)
 201 {
 202         struct platform_data *pdata = platform_get_drvdata(pdev);
 203         const struct attribute_group **pgroups = pdata->attr_groups;
 204         struct device_node *opal, *np;
 205         enum sensors type;
 206
 207         opal = of_find_node_by_path("/ibm,opal/sensors");
 208         for_each_child_of_node(opal, np) {
 209                 if (np->name == NULL)
 210                         continue;
 211
 212                 type = get_sensor_type(np);
 213                 if (type != MAX_SENSOR_TYPE)
 214                         sensor_groups[type].attr_count++;
 215         }
 216
 217         of_node_put(opal);
 218
 219         for (type = 0; type < MAX_SENSOR_TYPE; type++) {
 220                 sensor_groups[type].group.attrs = devm_kzalloc(&pdev->dev,
 221                                         sizeof(struct attribute *) *
 222                                         (sensor_groups[type].attr_count + 1),
 223                                         GFP_KERNEL);
 224                 if (!sensor_groups[type].group.attrs)
 225                         return -ENOMEM;
 226
 227                 pgroups[type] = &sensor_groups[type].group;
 228                 pdata->sensors_count += sensor_groups[type].attr_count;
 229                 sensor_groups[type].attr_count = 0;
 230         }
 231
 232         return 0;
 233 }
 234
 235 /*
 236  * Iterate through the device tree for each child of 'sensors' node, create
 237  * a sysfs attribute file, the file is named by translating the DT node name
 238  * to the name required by the higher 'hwmon' driver like fan1_input, temp1_max
 239  * etc..
 240  */
 241 static int create_device_attrs(struct platform_device *pdev)
 242 {
 243         struct platform_data *pdata = platform_get_drvdata(pdev);
 244         const struct attribute_group **pgroups = pdata->attr_groups;
 245         struct device_node *opal, *np;
 246         struct sensor_data *sdata;
 247         u32 sensor_id;
 248         enum sensors type;
 249         u32 count = 0;
 250         int err = 0;
 251
 252         opal = of_find_node_by_path("/ibm,opal/sensors");
 253         sdata = devm_kzalloc(&pdev->dev, pdata->sensors_count * sizeof(*sdata),
 254                              GFP_KERNEL);
 255         if (!sdata) {
 256                 err = -ENOMEM;
 257                 goto exit_put_node;
 258         }
 259
 260         for_each_child_of_node(opal, np) {
 261                 const char *attr_name;
 262                 u32 opal_index;
 263
 264                 if (np->name == NULL)
 265                         continue;
 266
 267                 type = get_sensor_type(np);
 268                 if (type == MAX_SENSOR_TYPE)
 269                         continue;
 270
 271                 if (of_property_read_u32(np, "sensor-id", &sensor_id)) {
 272                         dev_info(&pdev->dev,
 273                                  "'sensor-id' missing in the node '%s'\n",
 274                                  np->name);
 275                         continue;
 276                 }
 277
 278                 sdata[count].id = sensor_id;
 279                 sdata[count].type = type;
 280
 281                 attr_name = parse_opal_node_name(np->name, type, &opal_index);
 282                 if (IS_ERR(attr_name)) {
 283                         dev_err(&pdev->dev, "Sensor device node name '%s' is invalid\n",
 284                                 np->name);
 285                         err = PTR_ERR(attr_name);
 286                         goto exit_put_node;
 287                 }
 288
 289                 sdata[count].opal_index = opal_index;
 290                 sdata[count].hwmon_index =
 291                         get_sensor_hwmon_index(&sdata[count], sdata, count);
 292
 293                 snprintf(sdata[count].name, MAX_ATTR_LEN, "%s%d_%s",
 294                          sensor_groups[type].name, sdata[count].hwmon_index,
 295                          attr_name);
 296
 297                 sysfs_attr_init(&sdata[count].dev_attr.attr);
 298                 sdata[count].dev_attr.attr.name = sdata[count].name;
 299                 sdata[count].dev_attr.attr.mode = S_IRUGO;
 300                 sdata[count].dev_attr.show = show_sensor;
 301
 302                 pgroups[type]->attrs[sensor_groups[type].attr_count++] =
 303                                 &sdata[count++].dev_attr.attr;
 304         }
 305
 306 exit_put_node:
 307         of_node_put(opal);
 308         return err;
 309 }
 310
 311 static int ibmpowernv_probe(struct platform_device *pdev)
 312 {
 313         struct platform_data *pdata;
 314         struct device *hwmon_dev;
 315         int err;
 316
 317         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 318         if (!pdata)
 319                 return -ENOMEM;
 320
 321         platform_set_drvdata(pdev, pdata);
 322         pdata->sensors_count = 0;
 323         err = populate_attr_groups(pdev);
 324         if (err)
 325                 return err;
 326
 327         /* Create sysfs attribute data for each sensor found in the DT */
 328         err = create_device_attrs(pdev);
 329         if (err)
 330                 return err;
 331
 332         /* Finally, register with hwmon */
 333         hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev, DRVNAME,
 334                                                            pdata,
 335                                                            pdata->attr_groups);
 336
 337         return PTR_ERR_OR_ZERO(hwmon_dev);
 338 }
 339
 340 static const struct platform_device_id opal_sensor_driver_ids[] = {
 341         {
 342                 .name = "opal-sensor",
 343         },
 344         { }
 345 };
 346 MODULE_DEVICE_TABLE(platform, opal_sensor_driver_ids);
 347
 348 static struct platform_driver ibmpowernv_driver = {
 349         .probe          = ibmpowernv_probe,
 350         .id_table       = opal_sensor_driver_ids,
 351         .driver         = {
 352                 .name   = DRVNAME,
 353         },
 354 };
 355
 356 module_platform_driver(ibmpowernv_driver);
 357
 358 MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
 359 MODULE_DESCRIPTION("IBM POWERNV platform sensors");
 360 MODULE_LICENSE("GPL");