drivers/hwmon/ltc2990.c

   1 /*
   2  * Driver for Linear Technology LTC2990 power monitor
   3  *
   4  * Copyright (C) 2014 Topic Embedded Products
   5  * Author: Mike Looijmans <mike.looijmans@topic.nl>
   6  *
   7  * License: GPLv2
   8  */
   9
  10 #include <linux/bitops.h>
  11 #include <linux/err.h>
  12 #include <linux/hwmon.h>
  13 #include <linux/hwmon-sysfs.h>
  14 #include <linux/i2c.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/of.h>
  18
  19 #define LTC2990_STATUS  0x00
  20 #define LTC2990_CONTROL 0x01
  21 #define LTC2990_TRIGGER 0x02
  22 #define LTC2990_TINT_MSB        0x04
  23 #define LTC2990_V1_MSB  0x06
  24 #define LTC2990_V2_MSB  0x08
  25 #define LTC2990_V3_MSB  0x0A
  26 #define LTC2990_V4_MSB  0x0C
  27 #define LTC2990_VCC_MSB 0x0E
  28
  29 #define LTC2990_IN0     BIT(0)
  30 #define LTC2990_IN1     BIT(1)
  31 #define LTC2990_IN2     BIT(2)
  32 #define LTC2990_IN3     BIT(3)
  33 #define LTC2990_IN4     BIT(4)
  34 #define LTC2990_CURR1   BIT(5)
  35 #define LTC2990_CURR2   BIT(6)
  36 #define LTC2990_TEMP1   BIT(7)
  37 #define LTC2990_TEMP2   BIT(8)
  38 #define LTC2990_TEMP3   BIT(9)
  39 #define LTC2990_NONE    0
  40 #define LTC2990_ALL     GENMASK(9, 0)
  41
  42 #define LTC2990_MODE0_SHIFT     0
  43 #define LTC2990_MODE0_MASK      GENMASK(2, 0)
  44 #define LTC2990_MODE1_SHIFT     3
  45 #define LTC2990_MODE1_MASK      GENMASK(1, 0)
  46
  47 /* Enabled measurements for mode bits 2..0 */
  48 static const int ltc2990_attrs_ena_0[] = {
  49         LTC2990_IN1 | LTC2990_IN2 | LTC2990_TEMP3,
  50         LTC2990_CURR1 | LTC2990_TEMP3,
  51         LTC2990_CURR1 | LTC2990_IN3 | LTC2990_IN4,
  52         LTC2990_TEMP2 | LTC2990_IN3 | LTC2990_IN4,
  53         LTC2990_TEMP2 | LTC2990_CURR2,
  54         LTC2990_TEMP2 | LTC2990_TEMP3,
  55         LTC2990_CURR1 | LTC2990_CURR2,
  56         LTC2990_IN1 | LTC2990_IN2 | LTC2990_IN3 | LTC2990_IN4
  57 };
  58
  59 /* Enabled measurements for mode bits 4..3 */
  60 static const int ltc2990_attrs_ena_1[] = {
  61         LTC2990_NONE,
  62         LTC2990_TEMP2 | LTC2990_IN1 | LTC2990_CURR1,
  63         LTC2990_TEMP3 | LTC2990_IN3 | LTC2990_CURR2,
  64         LTC2990_ALL
  65 };
  66
  67 struct ltc2990_data {
  68         struct i2c_client *i2c;
  69         u32 mode[2];
  70 };
  71
  72 /* Return the converted value from the given register in uV or mC */
  73 static int ltc2990_get_value(struct i2c_client *i2c, int index, int *result)
  74 {
  75         int val;
  76         u8 reg;
  77
  78         switch (index) {
  79         case LTC2990_IN0:
  80                 reg = LTC2990_VCC_MSB;
  81                 break;
  82         case LTC2990_IN1:
  83         case LTC2990_CURR1:
  84         case LTC2990_TEMP2:
  85                 reg = LTC2990_V1_MSB;
  86                 break;
  87         case LTC2990_IN2:
  88                 reg = LTC2990_V2_MSB;
  89                 break;
  90         case LTC2990_IN3:
  91         case LTC2990_CURR2:
  92         case LTC2990_TEMP3:
  93                 reg = LTC2990_V3_MSB;
  94                 break;
  95         case LTC2990_IN4:
  96                 reg = LTC2990_V4_MSB;
  97                 break;
  98         case LTC2990_TEMP1:
  99                 reg = LTC2990_TINT_MSB;
 100                 break;
 101         default:
 102                 return -EINVAL;
 103         }
 104
 105         val = i2c_smbus_read_word_swapped(i2c, reg);
 106         if (unlikely(val < 0))
 107                 return val;
 108
 109         switch (index) {
 110         case LTC2990_TEMP1:
 111         case LTC2990_TEMP2:
 112         case LTC2990_TEMP3:
 113                 /* temp, 0.0625 degrees/LSB */
 114                 *result = sign_extend32(val, 12) * 1000 / 16;
 115                 break;
 116         case LTC2990_CURR1:
 117         case LTC2990_CURR2:
 118                  /* Vx-Vy, 19.42uV/LSB */
 119                 *result = sign_extend32(val, 14) * 1942 / 100;
 120                 break;
 121         case LTC2990_IN0:
 122                 /* Vcc, 305.18uV/LSB, 2.5V offset */
 123                 *result = sign_extend32(val, 14) * 30518 / (100 * 1000) + 2500;
 124                 break;
 125         case LTC2990_IN1:
 126         case LTC2990_IN2:
 127         case LTC2990_IN3:
 128         case LTC2990_IN4:
 129                 /* Vx, 305.18uV/LSB */
 130                 *result = sign_extend32(val, 14) * 30518 / (100 * 1000);
 131                 break;
 132         default:
 133                 return -EINVAL; /* won't happen, keep compiler happy */
 134         }
 135
 136         return 0;
 137 }
 138
 139 static ssize_t ltc2990_show_value(struct device *dev,
 140                                   struct device_attribute *da, char *buf)
 141 {
 142         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 143         struct ltc2990_data *data = dev_get_drvdata(dev);
 144         int value;
 145         int ret;
 146
 147         ret = ltc2990_get_value(data->i2c, attr->index, &value);
 148         if (unlikely(ret < 0))
 149                 return ret;
 150
 151         return snprintf(buf, PAGE_SIZE, "%d\n", value);
 152 }
 153
 154 static umode_t ltc2990_attrs_visible(struct kobject *kobj,
 155                                      struct attribute *a, int n)
 156 {
 157         struct device *dev = container_of(kobj, struct device, kobj);
 158         struct ltc2990_data *data = dev_get_drvdata(dev);
 159         struct device_attribute *da =
 160                         container_of(a, struct device_attribute, attr);
 161         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 162
 163         int attrs_mask = LTC2990_IN0 | LTC2990_TEMP1 |
 164                          (ltc2990_attrs_ena_0[data->mode[0]] &
 165                           ltc2990_attrs_ena_1[data->mode[1]]);
 166
 167         if (attr->index & attrs_mask)
 168                 return a->mode;
 169
 170         return 0;
 171 }
 172
 173 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ltc2990_show_value, NULL,
 174                           LTC2990_TEMP1);
 175 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, ltc2990_show_value, NULL,
 176                           LTC2990_TEMP2);
 177 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, ltc2990_show_value, NULL,
 178                           LTC2990_TEMP3);
 179 static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc2990_show_value, NULL,
 180                           LTC2990_CURR1);
 181 static SENSOR_DEVICE_ATTR(curr2_input, S_IRUGO, ltc2990_show_value, NULL,
 182                           LTC2990_CURR2);
 183 static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ltc2990_show_value, NULL,
 184                           LTC2990_IN0);
 185 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc2990_show_value, NULL,
 186                           LTC2990_IN1);
 187 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc2990_show_value, NULL,
 188                           LTC2990_IN2);
 189 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ltc2990_show_value, NULL,
 190                           LTC2990_IN3);
 191 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ltc2990_show_value, NULL,
 192                           LTC2990_IN4);
 193
 194 static struct attribute *ltc2990_attrs[] = {
 195         &sensor_dev_attr_temp1_input.dev_attr.attr,
 196         &sensor_dev_attr_temp2_input.dev_attr.attr,
 197         &sensor_dev_attr_temp3_input.dev_attr.attr,
 198         &sensor_dev_attr_curr1_input.dev_attr.attr,
 199         &sensor_dev_attr_curr2_input.dev_attr.attr,
 200         &sensor_dev_attr_in0_input.dev_attr.attr,
 201         &sensor_dev_attr_in1_input.dev_attr.attr,
 202         &sensor_dev_attr_in2_input.dev_attr.attr,
 203         &sensor_dev_attr_in3_input.dev_attr.attr,
 204         &sensor_dev_attr_in4_input.dev_attr.attr,
 205         NULL,
 206 };
 207
 208 static const struct attribute_group ltc2990_group = {
 209         .attrs = ltc2990_attrs,
 210         .is_visible = ltc2990_attrs_visible,
 211 };
 212 __ATTRIBUTE_GROUPS(ltc2990);
 213
 214 static int ltc2990_i2c_probe(struct i2c_client *i2c,
 215                              const struct i2c_device_id *id)
 216 {
 217         int ret;
 218         struct device *hwmon_dev;
 219         struct ltc2990_data *data;
 220         struct device_node *of_node = i2c->dev.of_node;
 221
 222         if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 223                                      I2C_FUNC_SMBUS_WORD_DATA))
 224                 return -ENODEV;
 225
 226         data = devm_kzalloc(&i2c->dev, sizeof(struct ltc2990_data), GFP_KERNEL);
 227         if (unlikely(!data))
 228                 return -ENOMEM;
 229
 230         data->i2c = i2c;
 231
 232         if (of_node) {
 233                 ret = of_property_read_u32_array(of_node, "lltc,meas-mode",
 234                                                  data->mode, 2);
 235                 if (ret < 0)
 236                         return ret;
 237
 238                 if (data->mode[0] & ~LTC2990_MODE0_MASK ||
 239                     data->mode[1] & ~LTC2990_MODE1_MASK)
 240                         return -EINVAL;
 241         } else {
 242                 ret = i2c_smbus_read_byte_data(i2c, LTC2990_CONTROL);
 243                 if (ret < 0)
 244                         return ret;
 245
 246                 data->mode[0] = ret >> LTC2990_MODE0_SHIFT & LTC2990_MODE0_MASK;
 247                 data->mode[1] = ret >> LTC2990_MODE1_SHIFT & LTC2990_MODE1_MASK;
 248         }
 249
 250         /* Setup continuous mode */
 251         ret = i2c_smbus_write_byte_data(i2c, LTC2990_CONTROL,
 252                                         data->mode[0] << LTC2990_MODE0_SHIFT |
 253                                         data->mode[1] << LTC2990_MODE1_SHIFT);
 254         if (ret < 0) {
 255                 dev_err(&i2c->dev, "Error: Failed to set control mode.\n");
 256                 return ret;
 257         }
 258         /* Trigger once to start continuous conversion */
 259         ret = i2c_smbus_write_byte_data(i2c, LTC2990_TRIGGER, 1);
 260         if (ret < 0) {
 261                 dev_err(&i2c->dev, "Error: Failed to start acquisition.\n");
 262                 return ret;
 263         }
 264
 265         hwmon_dev = devm_hwmon_device_register_with_groups(&i2c->dev,
 266                                                            i2c->name,
 267                                                            data,
 268                                                            ltc2990_groups);
 269
 270         return PTR_ERR_OR_ZERO(hwmon_dev);
 271 }
 272
 273 static const struct i2c_device_id ltc2990_i2c_id[] = {
 274         { "ltc2990", 0 },
 275         {}
 276 };
 277 MODULE_DEVICE_TABLE(i2c, ltc2990_i2c_id);
 278
 279 static struct i2c_driver ltc2990_i2c_driver = {
 280         .driver = {
 281                 .name = "ltc2990",
 282         },
 283         .probe    = ltc2990_i2c_probe,
 284         .id_table = ltc2990_i2c_id,
 285 };
 286
 287 module_i2c_driver(ltc2990_i2c_driver);
 288
 289 MODULE_DESCRIPTION("LTC2990 Sensor Driver");
 290 MODULE_AUTHOR("Topic Embedded Products");
 291 MODULE_LICENSE("GPL v2");