/* * Driver for Linear Technology LTC2990 power monitor * * Copyright (C) 2014 Topic Embedded Products * Author: Mike Looijmans <mike.looijmans@topic.nl> * * License: GPLv2 */ #include <linux/bitops.h> #include <linux/err.h> #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> #include <linux/i2c.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> #define LTC2990_STATUS 0x00 #define LTC2990_CONTROL 0x01 #define LTC2990_TRIGGER 0x02 #define LTC2990_TINT_MSB 0x04 #define LTC2990_V1_MSB 0x06 #define LTC2990_V2_MSB 0x08 #define LTC2990_V3_MSB 0x0A #define LTC2990_V4_MSB 0x0C #define LTC2990_VCC_MSB 0x0E #define LTC2990_IN0 BIT(0) #define LTC2990_IN1 BIT(1) #define LTC2990_IN2 BIT(2) #define LTC2990_IN3 BIT(3) #define LTC2990_IN4 BIT(4) #define LTC2990_CURR1 BIT(5) #define LTC2990_CURR2 BIT(6) #define LTC2990_TEMP1 BIT(7) #define LTC2990_TEMP2 BIT(8) #define LTC2990_TEMP3 BIT(9) #define LTC2990_NONE 0 #define LTC2990_ALL GENMASK(9, 0) #define LTC2990_MODE0_SHIFT 0 #define LTC2990_MODE0_MASK GENMASK(2, 0) #define LTC2990_MODE1_SHIFT 3 #define LTC2990_MODE1_MASK GENMASK(1, 0) /* Enabled measurements for mode bits 2..0 */ static const int ltc2990_attrs_ena_0[] = { LTC2990_IN1 | LTC2990_IN2 | LTC2990_TEMP3, LTC2990_CURR1 | LTC2990_TEMP3, LTC2990_CURR1 | LTC2990_IN3 | LTC2990_IN4, LTC2990_TEMP2 | LTC2990_IN3 | LTC2990_IN4, LTC2990_TEMP2 | LTC2990_CURR2, LTC2990_TEMP2 | LTC2990_TEMP3, LTC2990_CURR1 | LTC2990_CURR2, LTC2990_IN1 | LTC2990_IN2 | LTC2990_IN3 | LTC2990_IN4 }; /* Enabled measurements for mode bits 4..3 */ static const int ltc2990_attrs_ena_1[] = { LTC2990_NONE, LTC2990_TEMP2 | LTC2990_IN1 | LTC2990_CURR1, LTC2990_TEMP3 | LTC2990_IN3 | LTC2990_CURR2, LTC2990_ALL }; struct ltc2990_data { struct i2c_client *i2c; u32 mode[2]; }; /* Return the converted value from the given register in uV or mC */ static int ltc2990_get_value(struct i2c_client *i2c, int index, int *result) { int val; u8 reg; switch (index) { case LTC2990_IN0: reg = LTC2990_VCC_MSB; break; case LTC2990_IN1: case LTC2990_CURR1: case LTC2990_TEMP2: reg = LTC2990_V1_MSB; break; case LTC2990_IN2: reg = LTC2990_V2_MSB; break; case LTC2990_IN3: case LTC2990_CURR2: case LTC2990_TEMP3: reg = LTC2990_V3_MSB; break; case LTC2990_IN4: reg = LTC2990_V4_MSB; break; case LTC2990_TEMP1: reg = LTC2990_TINT_MSB; break; default: return -EINVAL; } val = i2c_smbus_read_word_swapped(i2c, reg); if (unlikely(val < 0)) return val; switch (index) { case LTC2990_TEMP1: case LTC2990_TEMP2: case LTC2990_TEMP3: /* temp, 0.0625 degrees/LSB */ *result = sign_extend32(val, 12) * 1000 / 16; break; case LTC2990_CURR1: case LTC2990_CURR2: /* Vx-Vy, 19.42uV/LSB */ *result = sign_extend32(val, 14) * 1942 / 100; break; case LTC2990_IN0: /* Vcc, 305.18uV/LSB, 2.5V offset */ *result = sign_extend32(val, 14) * 30518 / (100 * 1000) + 2500; break; case LTC2990_IN1: case LTC2990_IN2: case LTC2990_IN3: case LTC2990_IN4: /* Vx, 305.18uV/LSB */ *result = sign_extend32(val, 14) * 30518 / (100 * 1000); break; default: return -EINVAL; /* won't happen, keep compiler happy */ } return 0; } static ssize_t ltc2990_value_show(struct device *dev, struct device_attribute *da, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); struct ltc2990_data *data = dev_get_drvdata(dev); int value; int ret; ret = ltc2990_get_value(data->i2c, attr->index, &value); if (unlikely(ret < 0)) return ret; return snprintf(buf, PAGE_SIZE, "%d\n", value); } static umode_t ltc2990_attrs_visible(struct kobject *kobj, struct attribute *a, int n) { struct device *dev = container_of(kobj, struct device, kobj); struct ltc2990_data *data = dev_get_drvdata(dev); struct device_attribute *da = container_of(a, struct device_attribute, attr); struct sensor_device_attribute *attr = to_sensor_dev_attr(da); int attrs_mask = LTC2990_IN0 | LTC2990_TEMP1 | (ltc2990_attrs_ena_0[data->mode[0]] & ltc2990_attrs_ena_1[data->mode[1]]); if (attr->index & attrs_mask) return a->mode; return 0; } static SENSOR_DEVICE_ATTR_RO(temp1_input, ltc2990_value, LTC2990_TEMP1); static SENSOR_DEVICE_ATTR_RO(temp2_input, ltc2990_value, LTC2990_TEMP2); static SENSOR_DEVICE_ATTR_RO(temp3_input, ltc2990_value, LTC2990_TEMP3); static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc2990_value, LTC2990_CURR1); static SENSOR_DEVICE_ATTR_RO(curr2_input, ltc2990_value, LTC2990_CURR2); static SENSOR_DEVICE_ATTR_RO(in0_input, ltc2990_value, LTC2990_IN0); static SENSOR_DEVICE_ATTR_RO(in1_input, ltc2990_value, LTC2990_IN1); static SENSOR_DEVICE_ATTR_RO(in2_input, ltc2990_value, LTC2990_IN2); static SENSOR_DEVICE_ATTR_RO(in3_input, ltc2990_value, LTC2990_IN3); static SENSOR_DEVICE_ATTR_RO(in4_input, ltc2990_value, LTC2990_IN4); static struct attribute *ltc2990_attrs[] = { &sensor_dev_attr_temp1_input.dev_attr.attr, &sensor_dev_attr_temp2_input.dev_attr.attr, &sensor_dev_attr_temp3_input.dev_attr.attr, &sensor_dev_attr_curr1_input.dev_attr.attr, &sensor_dev_attr_curr2_input.dev_attr.attr, &sensor_dev_attr_in0_input.dev_attr.attr, &sensor_dev_attr_in1_input.dev_attr.attr, &sensor_dev_attr_in2_input.dev_attr.attr, &sensor_dev_attr_in3_input.dev_attr.attr, &sensor_dev_attr_in4_input.dev_attr.attr, NULL, }; static const struct attribute_group ltc2990_group = { .attrs = ltc2990_attrs, .is_visible = ltc2990_attrs_visible, }; __ATTRIBUTE_GROUPS(ltc2990); static int ltc2990_i2c_probe(struct i2c_client *i2c, const struct i2c_device_id *id) { int ret; struct device *hwmon_dev; struct ltc2990_data *data; struct device_node *of_node = i2c->dev.of_node; if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) return -ENODEV; data = devm_kzalloc(&i2c->dev, sizeof(struct ltc2990_data), GFP_KERNEL); if (unlikely(!data)) return -ENOMEM; data->i2c = i2c; if (of_node) { ret = of_property_read_u32_array(of_node, "lltc,meas-mode", data->mode, 2); if (ret < 0) return ret; if (data->mode[0] & ~LTC2990_MODE0_MASK || data->mode[1] & ~LTC2990_MODE1_MASK) return -EINVAL; } else { ret = i2c_smbus_read_byte_data(i2c, LTC2990_CONTROL); if (ret < 0) return ret; data->mode[0] = ret >> LTC2990_MODE0_SHIFT & LTC2990_MODE0_MASK; data->mode[1] = ret >> LTC2990_MODE1_SHIFT & LTC2990_MODE1_MASK; } /* Setup continuous mode */ ret = i2c_smbus_write_byte_data(i2c, LTC2990_CONTROL, data->mode[0] << LTC2990_MODE0_SHIFT | data->mode[1] << LTC2990_MODE1_SHIFT); if (ret < 0) { dev_err(&i2c->dev, "Error: Failed to set control mode.\n"); return ret; } /* Trigger once to start continuous conversion */ ret = i2c_smbus_write_byte_data(i2c, LTC2990_TRIGGER, 1); if (ret < 0) { dev_err(&i2c->dev, "Error: Failed to start acquisition.\n"); return ret; } hwmon_dev = devm_hwmon_device_register_with_groups(&i2c->dev, i2c->name, data, ltc2990_groups); return PTR_ERR_OR_ZERO(hwmon_dev); } static const struct i2c_device_id ltc2990_i2c_id[] = { { "ltc2990", 0 }, {} }; MODULE_DEVICE_TABLE(i2c, ltc2990_i2c_id); static struct i2c_driver ltc2990_i2c_driver = { .driver = { .name = "ltc2990", }, .probe = ltc2990_i2c_probe, .id_table = ltc2990_i2c_id, }; module_i2c_driver(ltc2990_i2c_driver); MODULE_DESCRIPTION("LTC2990 Sensor Driver"); MODULE_AUTHOR("Topic Embedded Products"); MODULE_LICENSE("GPL v2");