linux/drivers/hwmon/ltc2990.c
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   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 */
  47static 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 */
  59static 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
  66struct 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 */
  72static 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
 138static 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
 153static 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
 172static SENSOR_DEVICE_ATTR_RO(temp1_input, ltc2990_value, LTC2990_TEMP1);
 173static SENSOR_DEVICE_ATTR_RO(temp2_input, ltc2990_value, LTC2990_TEMP2);
 174static SENSOR_DEVICE_ATTR_RO(temp3_input, ltc2990_value, LTC2990_TEMP3);
 175static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc2990_value, LTC2990_CURR1);
 176static SENSOR_DEVICE_ATTR_RO(curr2_input, ltc2990_value, LTC2990_CURR2);
 177static SENSOR_DEVICE_ATTR_RO(in0_input, ltc2990_value, LTC2990_IN0);
 178static SENSOR_DEVICE_ATTR_RO(in1_input, ltc2990_value, LTC2990_IN1);
 179static SENSOR_DEVICE_ATTR_RO(in2_input, ltc2990_value, LTC2990_IN2);
 180static SENSOR_DEVICE_ATTR_RO(in3_input, ltc2990_value, LTC2990_IN3);
 181static SENSOR_DEVICE_ATTR_RO(in4_input, ltc2990_value, LTC2990_IN4);
 182
 183static 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
 197static const struct attribute_group ltc2990_group = {
 198        .attrs = ltc2990_attrs,
 199        .is_visible = ltc2990_attrs_visible,
 200};
 201__ATTRIBUTE_GROUPS(ltc2990);
 202
 203static 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
 261static const struct i2c_device_id ltc2990_i2c_id[] = {
 262        { "ltc2990", 0 },
 263        {}
 264};
 265MODULE_DEVICE_TABLE(i2c, ltc2990_i2c_id);
 266
 267static struct i2c_driver ltc2990_i2c_driver = {
 268        .driver = {
 269                .name = "ltc2990",
 270        },
 271        .probe_new = ltc2990_i2c_probe,
 272        .id_table = ltc2990_i2c_id,
 273};
 274
 275module_i2c_driver(ltc2990_i2c_driver);
 276
 277MODULE_DESCRIPTION("LTC2990 Sensor Driver");
 278MODULE_AUTHOR("Topic Embedded Products");
 279MODULE_LICENSE("GPL v2");
 280