diff options
Diffstat (limited to 'drivers/hwmon/ltc2990.c')
| -rw-r--r-- | drivers/hwmon/ltc2990.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/drivers/hwmon/ltc2990.c b/drivers/hwmon/ltc2990.c new file mode 100644 index 000000000..2aefdc58b --- /dev/null +++ b/drivers/hwmon/ltc2990.c @@ -0,0 +1,291 @@ +/* + * 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_show_value(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(temp1_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_TEMP1); +static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_TEMP2); +static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_TEMP3); +static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_CURR1); +static SENSOR_DEVICE_ATTR(curr2_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_CURR2); +static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_IN0); +static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_IN1); +static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_IN2); +static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_IN3); +static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ltc2990_show_value, NULL, + 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"); |