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         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
  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
 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  */
 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
 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_err(&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  */
 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
 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
 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                 pr_err("Platfrom driver probe failed\n");
 339                 goto exit_device_del;
 340         }
 341
 342         return 0;
 343
 344 exit_device_del:
 345         platform_device_del(pdevice);
 346 exit_device_put:
 347         platform_device_put(pdevice);
 348 exit:
 349         return err;
 350 }
 351
 352 static void __exit ibmpowernv_exit(void)
 353 {
 354         platform_driver_unregister(&ibmpowernv_driver);
 355         platform_device_unregister(pdevice);
 356 }
 357
 358 MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
 359 MODULE_DESCRIPTION("IBM POWERNV platform sensors");
 360 MODULE_LICENSE("GPL");
 361
 362 module_init(ibmpowernv_init);
 363 module_exit(ibmpowernv_exit);