drivers/hwmon/ltc2990.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Driver for Linear Technology LTC2990 power monitor
0004  *
0005  * Copyright (C) 2014 Topic Embedded Products
0006  * Author: Mike Looijmans <mike.looijmans@topic.nl>
0007  */
0008
0009 #include <linux/bitops.h>
0010 #include <linux/err.h>
0011 #include <linux/hwmon.h>
0012 #include <linux/hwmon-sysfs.h>
0013 #include <linux/i2c.h>
0014 #include <linux/kernel.h>
0015 #include <linux/module.h>
0016 #include <linux/property.h>
0017
0018 #define LTC2990_STATUS  0x00
0019 #define LTC2990_CONTROL 0x01
0020 #define LTC2990_TRIGGER 0x02
0021 #define LTC2990_TINT_MSB    0x04
0022 #define LTC2990_V1_MSB  0x06
0023 #define LTC2990_V2_MSB  0x08
0024 #define LTC2990_V3_MSB  0x0A
0025 #define LTC2990_V4_MSB  0x0C
0026 #define LTC2990_VCC_MSB 0x0E
0027
0028 #define LTC2990_IN0 BIT(0)
0029 #define LTC2990_IN1 BIT(1)
0030 #define LTC2990_IN2 BIT(2)
0031 #define LTC2990_IN3 BIT(3)
0032 #define LTC2990_IN4 BIT(4)
0033 #define LTC2990_CURR1   BIT(5)
0034 #define LTC2990_CURR2   BIT(6)
0035 #define LTC2990_TEMP1   BIT(7)
0036 #define LTC2990_TEMP2   BIT(8)
0037 #define LTC2990_TEMP3   BIT(9)
0038 #define LTC2990_NONE    0
0039 #define LTC2990_ALL GENMASK(9, 0)
0040
0041 #define LTC2990_MODE0_SHIFT 0
0042 #define LTC2990_MODE0_MASK  GENMASK(2, 0)
0043 #define LTC2990_MODE1_SHIFT 3
0044 #define LTC2990_MODE1_MASK  GENMASK(1, 0)
0045
0046 /* Enabled measurements for mode bits 2..0 */
0047 static const int ltc2990_attrs_ena_0[] = {
0048     LTC2990_IN1 | LTC2990_IN2 | LTC2990_TEMP3,
0049     LTC2990_CURR1 | LTC2990_TEMP3,
0050     LTC2990_CURR1 | LTC2990_IN3 | LTC2990_IN4,
0051     LTC2990_TEMP2 | LTC2990_IN3 | LTC2990_IN4,
0052     LTC2990_TEMP2 | LTC2990_CURR2,
0053     LTC2990_TEMP2 | LTC2990_TEMP3,
0054     LTC2990_CURR1 | LTC2990_CURR2,
0055     LTC2990_IN1 | LTC2990_IN2 | LTC2990_IN3 | LTC2990_IN4
0056 };
0057
0058 /* Enabled measurements for mode bits 4..3 */
0059 static const int ltc2990_attrs_ena_1[] = {
0060     LTC2990_NONE,
0061     LTC2990_TEMP2 | LTC2990_IN1 | LTC2990_CURR1,
0062     LTC2990_TEMP3 | LTC2990_IN3 | LTC2990_CURR2,
0063     LTC2990_ALL
0064 };
0065
0066 struct ltc2990_data {
0067     struct i2c_client *i2c;
0068     u32 mode[2];
0069 };
0070
0071 /* Return the converted value from the given register in uV or mC */
0072 static int ltc2990_get_value(struct i2c_client *i2c, int index, int *result)
0073 {
0074     int val;
0075     u8 reg;
0076
0077     switch (index) {
0078     case LTC2990_IN0:
0079         reg = LTC2990_VCC_MSB;
0080         break;
0081     case LTC2990_IN1:
0082     case LTC2990_CURR1:
0083     case LTC2990_TEMP2:
0084         reg = LTC2990_V1_MSB;
0085         break;
0086     case LTC2990_IN2:
0087         reg = LTC2990_V2_MSB;
0088         break;
0089     case LTC2990_IN3:
0090     case LTC2990_CURR2:
0091     case LTC2990_TEMP3:
0092         reg = LTC2990_V3_MSB;
0093         break;
0094     case LTC2990_IN4:
0095         reg = LTC2990_V4_MSB;
0096         break;
0097     case LTC2990_TEMP1:
0098         reg = LTC2990_TINT_MSB;
0099         break;
0100     default:
0101         return -EINVAL;
0102     }
0103
0104     val = i2c_smbus_read_word_swapped(i2c, reg);
0105     if (unlikely(val < 0))
0106         return val;
0107
0108     switch (index) {
0109     case LTC2990_TEMP1:
0110     case LTC2990_TEMP2:
0111     case LTC2990_TEMP3:
0112         /* temp, 0.0625 degrees/LSB */
0113         *result = sign_extend32(val, 12) * 1000 / 16;
0114         break;
0115     case LTC2990_CURR1:
0116     case LTC2990_CURR2:
0117          /* Vx-Vy, 19.42uV/LSB */
0118         *result = sign_extend32(val, 14) * 1942 / 100;
0119         break;
0120     case LTC2990_IN0:
0121         /* Vcc, 305.18uV/LSB, 2.5V offset */
0122         *result = sign_extend32(val, 14) * 30518 / (100 * 1000) + 2500;
0123         break;
0124     case LTC2990_IN1:
0125     case LTC2990_IN2:
0126     case LTC2990_IN3:
0127     case LTC2990_IN4:
0128         /* Vx, 305.18uV/LSB */
0129         *result = sign_extend32(val, 14) * 30518 / (100 * 1000);
0130         break;
0131     default:
0132         return -EINVAL; /* won't happen, keep compiler happy */
0133     }
0134
0135     return 0;
0136 }
0137
0138 static ssize_t ltc2990_value_show(struct device *dev,
0139                   struct device_attribute *da, char *buf)
0140 {
0141     struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
0142     struct ltc2990_data *data = dev_get_drvdata(dev);
0143     int value;
0144     int ret;
0145
0146     ret = ltc2990_get_value(data->i2c, attr->index, &value);
0147     if (unlikely(ret < 0))
0148         return ret;
0149
0150     return sysfs_emit(buf, "%d\n", value);
0151 }
0152
0153 static umode_t ltc2990_attrs_visible(struct kobject *kobj,
0154                      struct attribute *a, int n)
0155 {
0156     struct device *dev = kobj_to_dev(kobj);
0157     struct ltc2990_data *data = dev_get_drvdata(dev);
0158     struct device_attribute *da =
0159             container_of(a, struct device_attribute, attr);
0160     struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
0161
0162     int attrs_mask = LTC2990_IN0 | LTC2990_TEMP1 |
0163              (ltc2990_attrs_ena_0[data->mode[0]] &
0164               ltc2990_attrs_ena_1[data->mode[1]]);
0165
0166     if (attr->index & attrs_mask)
0167         return a->mode;
0168
0169     return 0;
0170 }
0171
0172 static SENSOR_DEVICE_ATTR_RO(temp1_input, ltc2990_value, LTC2990_TEMP1);
0173 static SENSOR_DEVICE_ATTR_RO(temp2_input, ltc2990_value, LTC2990_TEMP2);
0174 static SENSOR_DEVICE_ATTR_RO(temp3_input, ltc2990_value, LTC2990_TEMP3);
0175 static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc2990_value, LTC2990_CURR1);
0176 static SENSOR_DEVICE_ATTR_RO(curr2_input, ltc2990_value, LTC2990_CURR2);
0177 static SENSOR_DEVICE_ATTR_RO(in0_input, ltc2990_value, LTC2990_IN0);
0178 static SENSOR_DEVICE_ATTR_RO(in1_input, ltc2990_value, LTC2990_IN1);
0179 static SENSOR_DEVICE_ATTR_RO(in2_input, ltc2990_value, LTC2990_IN2);
0180 static SENSOR_DEVICE_ATTR_RO(in3_input, ltc2990_value, LTC2990_IN3);
0181 static SENSOR_DEVICE_ATTR_RO(in4_input, ltc2990_value, LTC2990_IN4);
0182
0183 static struct attribute *ltc2990_attrs[] = {
0184     &sensor_dev_attr_temp1_input.dev_attr.attr,
0185     &sensor_dev_attr_temp2_input.dev_attr.attr,
0186     &sensor_dev_attr_temp3_input.dev_attr.attr,
0187     &sensor_dev_attr_curr1_input.dev_attr.attr,
0188     &sensor_dev_attr_curr2_input.dev_attr.attr,
0189     &sensor_dev_attr_in0_input.dev_attr.attr,
0190     &sensor_dev_attr_in1_input.dev_attr.attr,
0191     &sensor_dev_attr_in2_input.dev_attr.attr,
0192     &sensor_dev_attr_in3_input.dev_attr.attr,
0193     &sensor_dev_attr_in4_input.dev_attr.attr,
0194     NULL,
0195 };
0196
0197 static const struct attribute_group ltc2990_group = {
0198     .attrs = ltc2990_attrs,
0199     .is_visible = ltc2990_attrs_visible,
0200 };
0201 __ATTRIBUTE_GROUPS(ltc2990);
0202
0203 static int ltc2990_i2c_probe(struct i2c_client *i2c)
0204 {
0205     int ret;
0206     struct device *hwmon_dev;
0207     struct ltc2990_data *data;
0208
0209     if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
0210                      I2C_FUNC_SMBUS_WORD_DATA))
0211         return -ENODEV;
0212
0213     data = devm_kzalloc(&i2c->dev, sizeof(struct ltc2990_data), GFP_KERNEL);
0214     if (unlikely(!data))
0215         return -ENOMEM;
0216
0217     data->i2c = i2c;
0218
0219     if (dev_fwnode(&i2c->dev)) {
0220         ret = device_property_read_u32_array(&i2c->dev,
0221                              "lltc,meas-mode",
0222                              data->mode, 2);
0223         if (ret < 0)
0224             return ret;
0225
0226         if (data->mode[0] & ~LTC2990_MODE0_MASK ||
0227             data->mode[1] & ~LTC2990_MODE1_MASK)
0228             return -EINVAL;
0229     } else {
0230         ret = i2c_smbus_read_byte_data(i2c, LTC2990_CONTROL);
0231         if (ret < 0)
0232             return ret;
0233
0234         data->mode[0] = ret >> LTC2990_MODE0_SHIFT & LTC2990_MODE0_MASK;
0235         data->mode[1] = ret >> LTC2990_MODE1_SHIFT & LTC2990_MODE1_MASK;
0236     }
0237
0238     /* Setup continuous mode */
0239     ret = i2c_smbus_write_byte_data(i2c, LTC2990_CONTROL,
0240                     data->mode[0] << LTC2990_MODE0_SHIFT |
0241                     data->mode[1] << LTC2990_MODE1_SHIFT);
0242     if (ret < 0) {
0243         dev_err(&i2c->dev, "Error: Failed to set control mode.\n");
0244         return ret;
0245     }
0246     /* Trigger once to start continuous conversion */
0247     ret = i2c_smbus_write_byte_data(i2c, LTC2990_TRIGGER, 1);
0248     if (ret < 0) {
0249         dev_err(&i2c->dev, "Error: Failed to start acquisition.\n");
0250         return ret;
0251     }
0252
0253     hwmon_dev = devm_hwmon_device_register_with_groups(&i2c->dev,
0254                                i2c->name,
0255                                data,
0256                                ltc2990_groups);
0257
0258     return PTR_ERR_OR_ZERO(hwmon_dev);
0259 }
0260
0261 static const struct i2c_device_id ltc2990_i2c_id[] = {
0262     { "ltc2990", 0 },
0263     {}
0264 };
0265 MODULE_DEVICE_TABLE(i2c, ltc2990_i2c_id);
0266
0267 static struct i2c_driver ltc2990_i2c_driver = {
0268     .driver = {
0269         .name = "ltc2990",
0270     },
0271     .probe_new = ltc2990_i2c_probe,
0272     .id_table = ltc2990_i2c_id,
0273 };
0274
0275 module_i2c_driver(ltc2990_i2c_driver);
0276
0277 MODULE_DESCRIPTION("LTC2990 Sensor Driver");
0278 MODULE_AUTHOR("Topic Embedded Products");
0279 MODULE_LICENSE("GPL v2");