drivers/hwmon/ltc2990.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Driver for Linear Technology LTC2990 power monitor
   4  *
   5  * Copyright (C) 2014 Topic Embedded Products
   6  * Author: Mike Looijmans <mike.looijmans@topic.nl>
   7  */
   8
   9 #include <linux/bitops.h>
  10 #include <linux/err.h>
  11 #include <linux/hwmon.h>
  12 #include <linux/hwmon-sysfs.h>
  13 #include <linux/i2c.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/property.h>
  17
  18 #define LTC2990_STATUS  0x00
  19 #define LTC2990_CONTROL 0x01
  20 #define LTC2990_TRIGGER 0x02
  21 #define LTC2990_TINT_MSB        0x04
  22 #define LTC2990_V1_MSB  0x06
  23 #define LTC2990_V2_MSB  0x08
  24 #define LTC2990_V3_MSB  0x0A
  25 #define LTC2990_V4_MSB  0x0C
  26 #define LTC2990_VCC_MSB 0x0E
  27
  28 #define LTC2990_IN0     BIT(0)
  29 #define LTC2990_IN1     BIT(1)
  30 #define LTC2990_IN2     BIT(2)
  31 #define LTC2990_IN3     BIT(3)
  32 #define LTC2990_IN4     BIT(4)
  33 #define LTC2990_CURR1   BIT(5)
  34 #define LTC2990_CURR2   BIT(6)
  35 #define LTC2990_TEMP1   BIT(7)
  36 #define LTC2990_TEMP2   BIT(8)
  37 #define LTC2990_TEMP3   BIT(9)
  38 #define LTC2990_NONE    0
  39 #define LTC2990_ALL     GENMASK(9, 0)
  40
  41 #define LTC2990_MODE0_SHIFT     0
  42 #define LTC2990_MODE0_MASK      GENMASK(2, 0)
  43 #define LTC2990_MODE1_SHIFT     3
  44 #define LTC2990_MODE1_MASK      GENMASK(1, 0)
  45
  46 /* Enabled measurements for mode bits 2..0 */
  47 static const int ltc2990_attrs_ena_0[] = {
  48         LTC2990_IN1 | LTC2990_IN2 | LTC2990_TEMP3,
  49         LTC2990_CURR1 | LTC2990_TEMP3,
  50         LTC2990_CURR1 | LTC2990_IN3 | LTC2990_IN4,
  51         LTC2990_TEMP2 | LTC2990_IN3 | LTC2990_IN4,
  52         LTC2990_TEMP2 | LTC2990_CURR2,
  53         LTC2990_TEMP2 | LTC2990_TEMP3,
  54         LTC2990_CURR1 | LTC2990_CURR2,
  55         LTC2990_IN1 | LTC2990_IN2 | LTC2990_IN3 | LTC2990_IN4
  56 };
  57
  58 /* Enabled measurements for mode bits 4..3 */
  59 static const int ltc2990_attrs_ena_1[] = {
  60         LTC2990_NONE,
  61         LTC2990_TEMP2 | LTC2990_IN1 | LTC2990_CURR1,
  62         LTC2990_TEMP3 | LTC2990_IN3 | LTC2990_CURR2,
  63         LTC2990_ALL
  64 };
  65
  66 struct ltc2990_data {
  67         struct i2c_client *i2c;
  68         u32 mode[2];
  69 };
  70
  71 /* Return the converted value from the given register in uV or mC */
  72 static int ltc2990_get_value(struct i2c_client *i2c, int index, int *result)
  73 {
  74         int val;
  75         u8 reg;
  76
  77         switch (index) {
  78         case LTC2990_IN0:
  79                 reg = LTC2990_VCC_MSB;
  80                 break;
  81         case LTC2990_IN1:
  82         case LTC2990_CURR1:
  83         case LTC2990_TEMP2:
  84                 reg = LTC2990_V1_MSB;
  85                 break;
  86         case LTC2990_IN2:
  87                 reg = LTC2990_V2_MSB;
  88                 break;
  89         case LTC2990_IN3:
  90         case LTC2990_CURR2:
  91         case LTC2990_TEMP3:
  92                 reg = LTC2990_V3_MSB;
  93                 break;
  94         case LTC2990_IN4:
  95                 reg = LTC2990_V4_MSB;
  96                 break;
  97         case LTC2990_TEMP1:
  98                 reg = LTC2990_TINT_MSB;
  99                 break;
 100         default:
 101                 return -EINVAL;
 102         }
 103
 104         val = i2c_smbus_read_word_swapped(i2c, reg);
 105         if (unlikely(val < 0))
 106                 return val;
 107
 108         switch (index) {
 109         case LTC2990_TEMP1:
 110         case LTC2990_TEMP2:
 111         case LTC2990_TEMP3:
 112                 /* temp, 0.0625 degrees/LSB */
 113                 *result = sign_extend32(val, 12) * 1000 / 16;
 114                 break;
 115         case LTC2990_CURR1:
 116         case LTC2990_CURR2:
 117                  /* Vx-Vy, 19.42uV/LSB */
 118                 *result = sign_extend32(val, 14) * 1942 / 100;
 119                 break;
 120         case LTC2990_IN0:
 121                 /* Vcc, 305.18uV/LSB, 2.5V offset */
 122                 *result = sign_extend32(val, 14) * 30518 / (100 * 1000) + 2500;
 123                 break;
 124         case LTC2990_IN1:
 125         case LTC2990_IN2:
 126         case LTC2990_IN3:
 127         case LTC2990_IN4:
 128                 /* Vx, 305.18uV/LSB */
 129                 *result = sign_extend32(val, 14) * 30518 / (100 * 1000);
 130                 break;
 131         default:
 132                 return -EINVAL; /* won't happen, keep compiler happy */
 133         }
 134
 135         return 0;
 136 }
 137
 138 static ssize_t ltc2990_value_show(struct device *dev,
 139                                   struct device_attribute *da, char *buf)
 140 {
 141         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 142         struct ltc2990_data *data = dev_get_drvdata(dev);
 143         int value;
 144         int ret;
 145
 146         ret = ltc2990_get_value(data->i2c, attr->index, &value);
 147         if (unlikely(ret < 0))
 148                 return ret;
 149
 150         return sysfs_emit(buf, "%d\n", value);
 151 }
 152
 153 static umode_t ltc2990_attrs_visible(struct kobject *kobj,
 154                                      struct attribute *a, int n)
 155 {
 156         struct device *dev = kobj_to_dev(kobj);
 157         struct ltc2990_data *data = dev_get_drvdata(dev);
 158         struct device_attribute *da =
 159                         container_of(a, struct device_attribute, attr);
 160         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 161
 162         int attrs_mask = LTC2990_IN0 | LTC2990_TEMP1 |
 163                          (ltc2990_attrs_ena_0[data->mode[0]] &
 164                           ltc2990_attrs_ena_1[data->mode[1]]);
 165
 166         if (attr->index & attrs_mask)
 167                 return a->mode;
 168
 169         return 0;
 170 }
 171
 172 static SENSOR_DEVICE_ATTR_RO(temp1_input, ltc2990_value, LTC2990_TEMP1);
 173 static SENSOR_DEVICE_ATTR_RO(temp2_input, ltc2990_value, LTC2990_TEMP2);
 174 static SENSOR_DEVICE_ATTR_RO(temp3_input, ltc2990_value, LTC2990_TEMP3);
 175 static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc2990_value, LTC2990_CURR1);
 176 static SENSOR_DEVICE_ATTR_RO(curr2_input, ltc2990_value, LTC2990_CURR2);
 177 static SENSOR_DEVICE_ATTR_RO(in0_input, ltc2990_value, LTC2990_IN0);
 178 static SENSOR_DEVICE_ATTR_RO(in1_input, ltc2990_value, LTC2990_IN1);
 179 static SENSOR_DEVICE_ATTR_RO(in2_input, ltc2990_value, LTC2990_IN2);
 180 static SENSOR_DEVICE_ATTR_RO(in3_input, ltc2990_value, LTC2990_IN3);
 181 static SENSOR_DEVICE_ATTR_RO(in4_input, ltc2990_value, LTC2990_IN4);
 182
 183 static struct attribute *ltc2990_attrs[] = {
 184         &sensor_dev_attr_temp1_input.dev_attr.attr,
 185         &sensor_dev_attr_temp2_input.dev_attr.attr,
 186         &sensor_dev_attr_temp3_input.dev_attr.attr,
 187         &sensor_dev_attr_curr1_input.dev_attr.attr,
 188         &sensor_dev_attr_curr2_input.dev_attr.attr,
 189         &sensor_dev_attr_in0_input.dev_attr.attr,
 190         &sensor_dev_attr_in1_input.dev_attr.attr,
 191         &sensor_dev_attr_in2_input.dev_attr.attr,
 192         &sensor_dev_attr_in3_input.dev_attr.attr,
 193         &sensor_dev_attr_in4_input.dev_attr.attr,
 194         NULL,
 195 };
 196
 197 static const struct attribute_group ltc2990_group = {
 198         .attrs = ltc2990_attrs,
 199         .is_visible = ltc2990_attrs_visible,
 200 };
 201 __ATTRIBUTE_GROUPS(ltc2990);
 202
 203 static int ltc2990_i2c_probe(struct i2c_client *i2c)
 204 {
 205         int ret;
 206         struct device *hwmon_dev;
 207         struct ltc2990_data *data;
 208
 209         if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 210                                      I2C_FUNC_SMBUS_WORD_DATA))
 211                 return -ENODEV;
 212
 213         data = devm_kzalloc(&i2c->dev, sizeof(struct ltc2990_data), GFP_KERNEL);
 214         if (unlikely(!data))
 215                 return -ENOMEM;
 216
 217         data->i2c = i2c;
 218
 219         if (dev_fwnode(&i2c->dev)) {
 220                 ret = device_property_read_u32_array(&i2c->dev,
 221                                                      "lltc,meas-mode",
 222                                                      data->mode, 2);
 223                 if (ret < 0)
 224                         return ret;
 225
 226                 if (data->mode[0] & ~LTC2990_MODE0_MASK ||
 227                     data->mode[1] & ~LTC2990_MODE1_MASK)
 228                         return -EINVAL;
 229         } else {
 230                 ret = i2c_smbus_read_byte_data(i2c, LTC2990_CONTROL);
 231                 if (ret < 0)
 232                         return ret;
 233
 234                 data->mode[0] = ret >> LTC2990_MODE0_SHIFT & LTC2990_MODE0_MASK;
 235                 data->mode[1] = ret >> LTC2990_MODE1_SHIFT & LTC2990_MODE1_MASK;
 236         }
 237
 238         /* Setup continuous mode */
 239         ret = i2c_smbus_write_byte_data(i2c, LTC2990_CONTROL,
 240                                         data->mode[0] << LTC2990_MODE0_SHIFT |
 241                                         data->mode[1] << LTC2990_MODE1_SHIFT);
 242         if (ret < 0) {
 243                 dev_err(&i2c->dev, "Error: Failed to set control mode.\n");
 244                 return ret;
 245         }
 246         /* Trigger once to start continuous conversion */
 247         ret = i2c_smbus_write_byte_data(i2c, LTC2990_TRIGGER, 1);
 248         if (ret < 0) {
 249                 dev_err(&i2c->dev, "Error: Failed to start acquisition.\n");
 250                 return ret;
 251         }
 252
 253         hwmon_dev = devm_hwmon_device_register_with_groups(&i2c->dev,
 254                                                            i2c->name,
 255                                                            data,
 256                                                            ltc2990_groups);
 257
 258         return PTR_ERR_OR_ZERO(hwmon_dev);
 259 }
 260
 261 static const struct i2c_device_id ltc2990_i2c_id[] = {
 262         { "ltc2990", 0 },
 263         {}
 264 };
 265 MODULE_DEVICE_TABLE(i2c, ltc2990_i2c_id);
 266
 267 static struct i2c_driver ltc2990_i2c_driver = {
 268         .driver = {
 269                 .name = "ltc2990",
 270         },
 271         .probe = ltc2990_i2c_probe,
 272         .id_table = ltc2990_i2c_id,
 273 };
 274
 275 module_i2c_driver(ltc2990_i2c_driver);
 276
 277 MODULE_DESCRIPTION("LTC2990 Sensor Driver");
 278 MODULE_AUTHOR("Topic Embedded Products");
 279 MODULE_LICENSE("GPL v2");