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 } 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 static ssize_t show_sensor(struct device *dev, struct device_attribute *devattr,
  78                            char *buf)
  79 {
  80         struct sensor_data *sdata = container_of(devattr, struct sensor_data,
  81                                                  dev_attr);
  82         ssize_t ret;
  83         u32 x;
  84
  85         ret = opal_get_sensor_data(sdata->id, &x);
  86         if (ret)
  87                 return ret;
  88
  89         /* Convert temperature to milli-degrees */
  90         if (sdata->type == TEMP)
  91                 x *= 1000;
  92         /* Convert power to micro-watts */
  93         else if (sdata->type == POWER_INPUT)
  94                 x *= 1000000;
  95
  96         return sprintf(buf, "%u\n", x);
  97 }
  98
  99 static int get_sensor_index_attr(const char *name, u32 *index,
 100                                         char *attr)
 101 {
 102         char *hash_pos = strchr(name, '#');
 103         char buf[8] = { 0 };
 104         char *dash_pos;
 105         u32 copy_len;
 106         int err;
 107
 108         if (!hash_pos)
 109                 return -EINVAL;
 110
 111         dash_pos = strchr(hash_pos, '-');
 112         if (!dash_pos)
 113                 return -EINVAL;
 114
 115         copy_len = dash_pos - hash_pos - 1;
 116         if (copy_len >= sizeof(buf))
 117                 return -EINVAL;
 118
 119         strncpy(buf, hash_pos + 1, copy_len);
 120
 121         err = kstrtou32(buf, 10, index);
 122         if (err)
 123                 return err;
 124
 125         strncpy(attr, dash_pos + 1, MAX_ATTR_LEN);
 126
 127         return 0;
 128 }
 129
 130 /*
 131  * This function translates the DT node name into the 'hwmon' attribute name.
 132  * IBMPOWERNV device node appear like cooling-fan#2-data, amb-temp#1-thrs etc.
 133  * which need to be mapped as fan2_input, temp1_max respectively before
 134  * populating them inside hwmon device class.
 135  */
 136 static int create_hwmon_attr_name(struct device *dev, enum sensors type,
 137                                          const char *node_name,
 138                                          char *hwmon_attr_name)
 139 {
 140         char attr_suffix[MAX_ATTR_LEN];
 141         char *attr_name;
 142         u32 index;
 143         int err;
 144
 145         err = get_sensor_index_attr(node_name, &index, attr_suffix);
 146         if (err) {
 147                 dev_err(dev, "Sensor device node name '%s' is invalid\n",
 148                         node_name);
 149                 return err;
 150         }
 151
 152         if (!strcmp(attr_suffix, DT_FAULT_ATTR_SUFFIX)) {
 153                 attr_name = "fault";
 154         } else if (!strcmp(attr_suffix, DT_DATA_ATTR_SUFFIX)) {
 155                 attr_name = "input";
 156         } else if (!strcmp(attr_suffix, DT_THRESHOLD_ATTR_SUFFIX)) {
 157                 if (type == TEMP)
 158                         attr_name = "max";
 159                 else if (type == FAN)
 160                         attr_name = "min";
 161                 else
 162                         return -ENOENT;
 163         } else {
 164                 return -ENOENT;
 165         }
 166
 167         snprintf(hwmon_attr_name, MAX_ATTR_LEN, "%s%d_%s",
 168                  sensor_groups[type].name, index, attr_name);
 169         return 0;
 170 }
 171
 172 static int populate_attr_groups(struct platform_device *pdev)
 173 {
 174         struct platform_data *pdata = platform_get_drvdata(pdev);
 175         const struct attribute_group **pgroups = pdata->attr_groups;
 176         struct device_node *opal, *np;
 177         enum sensors type;
 178
 179         opal = of_find_node_by_path("/ibm,opal/sensors");
 180         for_each_child_of_node(opal, np) {
 181                 if (np->name == NULL)
 182                         continue;
 183
 184                 for (type = 0; type < MAX_SENSOR_TYPE; type++)
 185                         if (of_device_is_compatible(np,
 186                                         sensor_groups[type].compatible)) {
 187                                 sensor_groups[type].attr_count++;
 188                                 break;
 189                         }
 190         }
 191
 192         of_node_put(opal);
 193
 194         for (type = 0; type < MAX_SENSOR_TYPE; type++) {
 195                 sensor_groups[type].group.attrs = devm_kzalloc(&pdev->dev,
 196                                         sizeof(struct attribute *) *
 197                                         (sensor_groups[type].attr_count + 1),
 198                                         GFP_KERNEL);
 199                 if (!sensor_groups[type].group.attrs)
 200                         return -ENOMEM;
 201
 202                 pgroups[type] = &sensor_groups[type].group;
 203                 pdata->sensors_count += sensor_groups[type].attr_count;
 204                 sensor_groups[type].attr_count = 0;
 205         }
 206
 207         return 0;
 208 }
 209
 210 /*
 211  * Iterate through the device tree for each child of 'sensors' node, create
 212  * a sysfs attribute file, the file is named by translating the DT node name
 213  * to the name required by the higher 'hwmon' driver like fan1_input, temp1_max
 214  * etc..
 215  */
 216 static int create_device_attrs(struct platform_device *pdev)
 217 {
 218         struct platform_data *pdata = platform_get_drvdata(pdev);
 219         const struct attribute_group **pgroups = pdata->attr_groups;
 220         struct device_node *opal, *np;
 221         struct sensor_data *sdata;
 222         u32 sensor_id;
 223         enum sensors type;
 224         u32 count = 0;
 225         int err = 0;
 226
 227         opal = of_find_node_by_path("/ibm,opal/sensors");
 228         sdata = devm_kzalloc(&pdev->dev, pdata->sensors_count * sizeof(*sdata),
 229                              GFP_KERNEL);
 230         if (!sdata) {
 231                 err = -ENOMEM;
 232                 goto exit_put_node;
 233         }
 234
 235         for_each_child_of_node(opal, np) {
 236                 if (np->name == NULL)
 237                         continue;
 238
 239                 for (type = 0; type < MAX_SENSOR_TYPE; type++)
 240                         if (of_device_is_compatible(np,
 241                                         sensor_groups[type].compatible))
 242                                 break;
 243
 244                 if (type == MAX_SENSOR_TYPE)
 245                         continue;
 246
 247                 if (of_property_read_u32(np, "sensor-id", &sensor_id)) {
 248                         dev_info(&pdev->dev,
 249                                  "'sensor-id' missing in the node '%s'\n",
 250                                  np->name);
 251                         continue;
 252                 }
 253
 254                 sdata[count].id = sensor_id;
 255                 sdata[count].type = type;
 256                 err = create_hwmon_attr_name(&pdev->dev, type, np->name,
 257                                              sdata[count].name);
 258                 if (err)
 259                         goto exit_put_node;
 260
 261                 sysfs_attr_init(&sdata[count].dev_attr.attr);
 262                 sdata[count].dev_attr.attr.name = sdata[count].name;
 263                 sdata[count].dev_attr.attr.mode = S_IRUGO;
 264                 sdata[count].dev_attr.show = show_sensor;
 265
 266                 pgroups[type]->attrs[sensor_groups[type].attr_count++] =
 267                                 &sdata[count++].dev_attr.attr;
 268         }
 269
 270 exit_put_node:
 271         of_node_put(opal);
 272         return err;
 273 }
 274
 275 static int ibmpowernv_probe(struct platform_device *pdev)
 276 {
 277         struct platform_data *pdata;
 278         struct device *hwmon_dev;
 279         int err;
 280
 281         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 282         if (!pdata)
 283                 return -ENOMEM;
 284
 285         platform_set_drvdata(pdev, pdata);
 286         pdata->sensors_count = 0;
 287         err = populate_attr_groups(pdev);
 288         if (err)
 289                 return err;
 290
 291         /* Create sysfs attribute data for each sensor found in the DT */
 292         err = create_device_attrs(pdev);
 293         if (err)
 294                 return err;
 295
 296         /* Finally, register with hwmon */
 297         hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev, DRVNAME,
 298                                                            pdata,
 299                                                            pdata->attr_groups);
 300
 301         return PTR_ERR_OR_ZERO(hwmon_dev);
 302 }
 303
 304 static const struct platform_device_id opal_sensor_driver_ids[] = {
 305         {
 306                 .name = "opal-sensor",
 307         },
 308         { }
 309 };
 310 MODULE_DEVICE_TABLE(platform, opal_sensor_driver_ids);
 311
 312 static struct platform_driver ibmpowernv_driver = {
 313         .probe          = ibmpowernv_probe,
 314         .id_table       = opal_sensor_driver_ids,
 315         .driver         = {
 316                 .name   = DRVNAME,
 317         },
 318 };
 319
 320 module_platform_driver(ibmpowernv_driver);
 321
 322 MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
 323 MODULE_DESCRIPTION("IBM POWERNV platform sensors");
 324 MODULE_LICENSE("GPL");