drivers/hwmon/gsc-hwmon.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Driver for Gateworks System Controller Hardware Monitor module
   4  *
   5  * Copyright (C) 2020 Gateworks Corporation
   6  */
   7 #include <linux/hwmon.h>
   8 #include <linux/hwmon-sysfs.h>
   9 #include <linux/mfd/gsc.h>
  10 #include <linux/module.h>
  11 #include <linux/of.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/regmap.h>
  14 #include <linux/slab.h>
  15
  16 #include <linux/platform_data/gsc_hwmon.h>
  17
  18 #define GSC_HWMON_MAX_TEMP_CH   16
  19 #define GSC_HWMON_MAX_IN_CH     16
  20 #define GSC_HWMON_MAX_FAN_CH    16
  21
  22 #define GSC_HWMON_RESOLUTION    12
  23 #define GSC_HWMON_VREF          2500
  24
  25 struct gsc_hwmon_data {
  26         struct gsc_dev *gsc;
  27         struct gsc_hwmon_platform_data *pdata;
  28         struct regmap *regmap;
  29         const struct gsc_hwmon_channel *temp_ch[GSC_HWMON_MAX_TEMP_CH];
  30         const struct gsc_hwmon_channel *in_ch[GSC_HWMON_MAX_IN_CH];
  31         const struct gsc_hwmon_channel *fan_ch[GSC_HWMON_MAX_FAN_CH];
  32         u32 temp_config[GSC_HWMON_MAX_TEMP_CH + 1];
  33         u32 in_config[GSC_HWMON_MAX_IN_CH + 1];
  34         u32 fan_config[GSC_HWMON_MAX_FAN_CH + 1];
  35         struct hwmon_channel_info temp_info;
  36         struct hwmon_channel_info in_info;
  37         struct hwmon_channel_info fan_info;
  38         const struct hwmon_channel_info *info[4];
  39         struct hwmon_chip_info chip;
  40 };
  41
  42 static struct regmap_bus gsc_hwmon_regmap_bus = {
  43         .reg_read = gsc_read,
  44         .reg_write = gsc_write,
  45 };
  46
  47 static const struct regmap_config gsc_hwmon_regmap_config = {
  48         .reg_bits = 8,
  49         .val_bits = 8,
  50         .cache_type = REGCACHE_NONE,
  51 };
  52
  53 static ssize_t pwm_auto_point_temp_show(struct device *dev,
  54                                         struct device_attribute *devattr,
  55                                         char *buf)
  56 {
  57         struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
  58         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  59         u8 reg = hwmon->pdata->fan_base + (2 * attr->index);
  60         u8 regs[2];
  61         int ret;
  62
  63         ret = regmap_bulk_read(hwmon->regmap, reg, regs, 2);
  64         if (ret)
  65                 return ret;
  66
  67         ret = regs[0] | regs[1] << 8;
  68         return sprintf(buf, "%d\n", ret * 10);
  69 }
  70
  71 static ssize_t pwm_auto_point_temp_store(struct device *dev,
  72                                          struct device_attribute *devattr,
  73                                          const char *buf, size_t count)
  74 {
  75         struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
  76         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  77         u8 reg = hwmon->pdata->fan_base + (2 * attr->index);
  78         u8 regs[2];
  79         long temp;
  80         int err;
  81
  82         if (kstrtol(buf, 10, &temp))
  83                 return -EINVAL;
  84
  85         temp = clamp_val(temp, 0, 10000);
  86         temp = DIV_ROUND_CLOSEST(temp, 10);
  87
  88         regs[0] = temp & 0xff;
  89         regs[1] = (temp >> 8) & 0xff;
  90         err = regmap_bulk_write(hwmon->regmap, reg, regs, 2);
  91         if (err)
  92                 return err;
  93
  94         return count;
  95 }
  96
  97 static ssize_t pwm_auto_point_pwm_show(struct device *dev,
  98                                        struct device_attribute *devattr,
  99                                        char *buf)
 100 {
 101         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 102
 103         return sprintf(buf, "%d\n", 255 * (50 + (attr->index * 10)) / 100);
 104 }
 105
 106 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point1_pwm, pwm_auto_point_pwm, 0);
 107 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point1_temp, pwm_auto_point_temp, 0);
 108
 109 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point2_pwm, pwm_auto_point_pwm, 1);
 110 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point2_temp, pwm_auto_point_temp, 1);
 111
 112 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point3_pwm, pwm_auto_point_pwm, 2);
 113 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point3_temp, pwm_auto_point_temp, 2);
 114
 115 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point4_pwm, pwm_auto_point_pwm, 3);
 116 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point4_temp, pwm_auto_point_temp, 3);
 117
 118 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point5_pwm, pwm_auto_point_pwm, 4);
 119 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point5_temp, pwm_auto_point_temp, 4);
 120
 121 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point6_pwm, pwm_auto_point_pwm, 5);
 122 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point6_temp, pwm_auto_point_temp, 5);
 123
 124 static struct attribute *gsc_hwmon_attributes[] = {
 125         &sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
 126         &sensor_dev_attr_pwm1_auto_point1_temp.dev_attr.attr,
 127         &sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
 128         &sensor_dev_attr_pwm1_auto_point2_temp.dev_attr.attr,
 129         &sensor_dev_attr_pwm1_auto_point3_pwm.dev_attr.attr,
 130         &sensor_dev_attr_pwm1_auto_point3_temp.dev_attr.attr,
 131         &sensor_dev_attr_pwm1_auto_point4_pwm.dev_attr.attr,
 132         &sensor_dev_attr_pwm1_auto_point4_temp.dev_attr.attr,
 133         &sensor_dev_attr_pwm1_auto_point5_pwm.dev_attr.attr,
 134         &sensor_dev_attr_pwm1_auto_point5_temp.dev_attr.attr,
 135         &sensor_dev_attr_pwm1_auto_point6_pwm.dev_attr.attr,
 136         &sensor_dev_attr_pwm1_auto_point6_temp.dev_attr.attr,
 137         NULL
 138 };
 139
 140 static const struct attribute_group gsc_hwmon_group = {
 141         .attrs = gsc_hwmon_attributes,
 142 };
 143 __ATTRIBUTE_GROUPS(gsc_hwmon);
 144
 145 static int
 146 gsc_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 147                int channel, long *val)
 148 {
 149         struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
 150         const struct gsc_hwmon_channel *ch;
 151         int sz, ret;
 152         long tmp;
 153         u8 buf[3];
 154
 155         switch (type) {
 156         case hwmon_in:
 157                 ch = hwmon->in_ch[channel];
 158                 break;
 159         case hwmon_temp:
 160                 ch = hwmon->temp_ch[channel];
 161                 break;
 162         case hwmon_fan:
 163                 ch = hwmon->fan_ch[channel];
 164                 break;
 165         default:
 166                 return -EOPNOTSUPP;
 167         }
 168
 169         sz = (ch->mode == mode_voltage_24bit) ? 3 : 2;
 170         ret = regmap_bulk_read(hwmon->regmap, ch->reg, buf, sz);
 171         if (ret)
 172                 return ret;
 173
 174         tmp = 0;
 175         while (sz-- > 0)
 176                 tmp |= (buf[sz] << (8 * sz));
 177
 178         switch (ch->mode) {
 179         case mode_temperature:
 180                 if (tmp > 0x8000)
 181                         tmp -= 0xffff;
 182                 tmp *= 100; /* convert to millidegrees celsius */
 183                 break;
 184         case mode_voltage_raw:
 185                 tmp = clamp_val(tmp, 0, BIT(GSC_HWMON_RESOLUTION));
 186                 /* scale based on ref voltage and ADC resolution */
 187                 tmp *= GSC_HWMON_VREF;
 188                 tmp >>= GSC_HWMON_RESOLUTION;
 189                 /* scale based on optional voltage divider */
 190                 if (ch->vdiv[0] && ch->vdiv[1]) {
 191                         tmp *= (ch->vdiv[0] + ch->vdiv[1]);
 192                         tmp /= ch->vdiv[1];
 193                 }
 194                 /* adjust by uV offset */
 195                 tmp += ch->mvoffset;
 196                 break;
 197         case mode_fan:
 198                 tmp *= 30; /* convert to revolutions per minute */
 199                 break;
 200         case mode_voltage_24bit:
 201         case mode_voltage_16bit:
 202                 /* no adjustment needed */
 203                 break;
 204         }
 205
 206         *val = tmp;
 207
 208         return 0;
 209 }
 210
 211 static int
 212 gsc_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,
 213                       u32 attr, int channel, const char **buf)
 214 {
 215         struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
 216
 217         switch (type) {
 218         case hwmon_in:
 219                 *buf = hwmon->in_ch[channel]->name;
 220                 break;
 221         case hwmon_temp:
 222                 *buf = hwmon->temp_ch[channel]->name;
 223                 break;
 224         case hwmon_fan:
 225                 *buf = hwmon->fan_ch[channel]->name;
 226                 break;
 227         default:
 228                 return -ENOTSUPP;
 229         }
 230
 231         return 0;
 232 }
 233
 234 static umode_t
 235 gsc_hwmon_is_visible(const void *_data, enum hwmon_sensor_types type, u32 attr,
 236                      int ch)
 237 {
 238         return 0444;
 239 }
 240
 241 static const struct hwmon_ops gsc_hwmon_ops = {
 242         .is_visible = gsc_hwmon_is_visible,
 243         .read = gsc_hwmon_read,
 244         .read_string = gsc_hwmon_read_string,
 245 };
 246
 247 static struct gsc_hwmon_platform_data *
 248 gsc_hwmon_get_devtree_pdata(struct device *dev)
 249 {
 250         struct gsc_hwmon_platform_data *pdata;
 251         struct gsc_hwmon_channel *ch;
 252         struct fwnode_handle *child;
 253         struct device_node *fan;
 254         int nchannels;
 255
 256         nchannels = device_get_child_node_count(dev);
 257         if (nchannels == 0)
 258                 return ERR_PTR(-ENODEV);
 259
 260         pdata = devm_kzalloc(dev, struct_size(pdata, channels, nchannels),
 261                              GFP_KERNEL);
 262         if (!pdata)
 263                 return ERR_PTR(-ENOMEM);
 264         pdata->nchannels = nchannels;
 265
 266         /* fan controller base address */
 267         of_node_get(dev->parent->of_node);
 268         fan = of_find_compatible_node(dev->parent->of_node, NULL, "gw,gsc-fan");
 269         if (fan && of_property_read_u32(fan, "reg", &pdata->fan_base)) {
 270                 of_node_put(fan);
 271                 dev_err(dev, "fan node without base\n");
 272                 return ERR_PTR(-EINVAL);
 273         }
 274
 275         of_node_put(fan);
 276
 277         ch = pdata->channels;
 278         /* allocate structures for channels and count instances of each type */
 279         device_for_each_child_node(dev, child) {
 280                 if (fwnode_property_read_string(child, "label", &ch->name)) {
 281                         dev_err(dev, "channel without label\n");
 282                         fwnode_handle_put(child);
 283                         return ERR_PTR(-EINVAL);
 284                 }
 285                 if (fwnode_property_read_u32(child, "reg", &ch->reg)) {
 286                         dev_err(dev, "channel without reg\n");
 287                         fwnode_handle_put(child);
 288                         return ERR_PTR(-EINVAL);
 289                 }
 290                 if (fwnode_property_read_u32(child, "gw,mode", &ch->mode)) {
 291                         dev_err(dev, "channel without mode\n");
 292                         fwnode_handle_put(child);
 293                         return ERR_PTR(-EINVAL);
 294                 }
 295                 if (ch->mode > mode_max) {
 296                         dev_err(dev, "invalid channel mode\n");
 297                         fwnode_handle_put(child);
 298                         return ERR_PTR(-EINVAL);
 299                 }
 300
 301                 if (!fwnode_property_read_u32(child,
 302                                               "gw,voltage-offset-microvolt",
 303                                               &ch->mvoffset))
 304                         ch->mvoffset /= 1000;
 305                 fwnode_property_read_u32_array(child,
 306                                                "gw,voltage-divider-ohms",
 307                                                ch->vdiv, ARRAY_SIZE(ch->vdiv));
 308                 ch++;
 309         }
 310
 311         return pdata;
 312 }
 313
 314 static int gsc_hwmon_probe(struct platform_device *pdev)
 315 {
 316         struct gsc_dev *gsc = dev_get_drvdata(pdev->dev.parent);
 317         struct device *dev = &pdev->dev;
 318         struct device *hwmon_dev;
 319         struct gsc_hwmon_platform_data *pdata = dev_get_platdata(dev);
 320         struct gsc_hwmon_data *hwmon;
 321         const struct attribute_group **groups;
 322         int i, i_in, i_temp, i_fan;
 323
 324         if (!pdata) {
 325                 pdata = gsc_hwmon_get_devtree_pdata(dev);
 326                 if (IS_ERR(pdata))
 327                         return PTR_ERR(pdata);
 328         }
 329
 330         hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
 331         if (!hwmon)
 332                 return -ENOMEM;
 333         hwmon->gsc = gsc;
 334         hwmon->pdata = pdata;
 335
 336         hwmon->regmap = devm_regmap_init(dev, &gsc_hwmon_regmap_bus,
 337                                          gsc->i2c_hwmon,
 338                                          &gsc_hwmon_regmap_config);
 339         if (IS_ERR(hwmon->regmap))
 340                 return PTR_ERR(hwmon->regmap);
 341
 342         for (i = 0, i_in = 0, i_temp = 0, i_fan = 0; i < hwmon->pdata->nchannels; i++) {
 343                 const struct gsc_hwmon_channel *ch = &pdata->channels[i];
 344
 345                 switch (ch->mode) {
 346                 case mode_temperature:
 347                         if (i_temp == GSC_HWMON_MAX_TEMP_CH) {
 348                                 dev_err(gsc->dev, "too many temp channels\n");
 349                                 return -EINVAL;
 350                         }
 351                         hwmon->temp_ch[i_temp] = ch;
 352                         hwmon->temp_config[i_temp] = HWMON_T_INPUT |
 353                                                      HWMON_T_LABEL;
 354                         i_temp++;
 355                         break;
 356                 case mode_fan:
 357                         if (i_fan == GSC_HWMON_MAX_FAN_CH) {
 358                                 dev_err(gsc->dev, "too many fan channels\n");
 359                                 return -EINVAL;
 360                         }
 361                         hwmon->fan_ch[i_fan] = ch;
 362                         hwmon->fan_config[i_fan] = HWMON_F_INPUT |
 363                                                    HWMON_F_LABEL;
 364                         i_fan++;
 365                         break;
 366                 case mode_voltage_24bit:
 367                 case mode_voltage_16bit:
 368                 case mode_voltage_raw:
 369                         if (i_in == GSC_HWMON_MAX_IN_CH) {
 370                                 dev_err(gsc->dev, "too many input channels\n");
 371                                 return -EINVAL;
 372                         }
 373                         hwmon->in_ch[i_in] = ch;
 374                         hwmon->in_config[i_in] =
 375                                 HWMON_I_INPUT | HWMON_I_LABEL;
 376                         i_in++;
 377                         break;
 378                 default:
 379                         dev_err(gsc->dev, "invalid mode: %d\n", ch->mode);
 380                         return -EINVAL;
 381                 }
 382         }
 383
 384         /* setup config structures */
 385         hwmon->chip.ops = &gsc_hwmon_ops;
 386         hwmon->chip.info = hwmon->info;
 387         hwmon->info[0] = &hwmon->temp_info;
 388         hwmon->info[1] = &hwmon->in_info;
 389         hwmon->info[2] = &hwmon->fan_info;
 390         hwmon->temp_info.type = hwmon_temp;
 391         hwmon->temp_info.config = hwmon->temp_config;
 392         hwmon->in_info.type = hwmon_in;
 393         hwmon->in_info.config = hwmon->in_config;
 394         hwmon->fan_info.type = hwmon_fan;
 395         hwmon->fan_info.config = hwmon->fan_config;
 396
 397         groups = pdata->fan_base ? gsc_hwmon_groups : NULL;
 398         hwmon_dev = devm_hwmon_device_register_with_info(dev,
 399                                                          KBUILD_MODNAME, hwmon,
 400                                                          &hwmon->chip, groups);
 401         return PTR_ERR_OR_ZERO(hwmon_dev);
 402 }
 403
 404 static const struct of_device_id gsc_hwmon_of_match[] = {
 405         { .compatible = "gw,gsc-adc", },
 406         {}
 407 };
 408
 409 static struct platform_driver gsc_hwmon_driver = {
 410         .driver = {
 411                 .name = "gsc-hwmon",
 412                 .of_match_table = gsc_hwmon_of_match,
 413         },
 414         .probe = gsc_hwmon_probe,
 415 };
 416
 417 module_platform_driver(gsc_hwmon_driver);
 418
 419 MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>");
 420 MODULE_DESCRIPTION("GSC hardware monitor driver");
 421 MODULE_LICENSE("GPL v2");