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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 | // SPDX-License-Identifier: GPL-2.0-or-later /* * Driver for Linear Technology LTC4260 I2C Positive Voltage Hot Swap Controller * * Copyright (c) 2014 Guenter Roeck */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/err.h> #include <linux/slab.h> #include <linux/i2c.h> #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> #include <linux/jiffies.h> #include <linux/regmap.h> /* chip registers */ #define LTC4260_CONTROL 0x00 #define LTC4260_ALERT 0x01 #define LTC4260_STATUS 0x02 #define LTC4260_FAULT 0x03 #define LTC4260_SENSE 0x04 #define LTC4260_SOURCE 0x05 #define LTC4260_ADIN 0x06 /* * Fault register bits */ #define FAULT_OV (1 << 0) #define FAULT_UV (1 << 1) #define FAULT_OC (1 << 2) #define FAULT_POWER_BAD (1 << 3) #define FAULT_FET_SHORT (1 << 5) /* Return the voltage from the given register in mV or mA */ static int ltc4260_get_value(struct device *dev, u8 reg) { struct regmap *regmap = dev_get_drvdata(dev); unsigned int val; int ret; ret = regmap_read(regmap, reg, &val); if (ret < 0) return ret; switch (reg) { case LTC4260_ADIN: /* 10 mV resolution. Convert to mV. */ val = val * 10; break; case LTC4260_SOURCE: /* 400 mV resolution. Convert to mV. */ val = val * 400; break; case LTC4260_SENSE: /* * 300 uV resolution. Convert to current as measured with * an 1 mOhm sense resistor, in mA. If a different sense * resistor is installed, calculate the actual current by * dividing the reported current by the sense resistor value * in mOhm. */ val = val * 300; break; default: return -EINVAL; } return val; } static ssize_t ltc4260_value_show(struct device *dev, struct device_attribute *da, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); int value; value = ltc4260_get_value(dev, attr->index); if (value < 0) return value; return sysfs_emit(buf, "%d\n", value); } static ssize_t ltc4260_bool_show(struct device *dev, struct device_attribute *da, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); struct regmap *regmap = dev_get_drvdata(dev); unsigned int fault; int ret; ret = regmap_read(regmap, LTC4260_FAULT, &fault); if (ret < 0) return ret; fault &= attr->index; if (fault) /* Clear reported faults in chip register */ regmap_update_bits(regmap, LTC4260_FAULT, attr->index, 0); return sysfs_emit(buf, "%d\n", !!fault); } /* Voltages */ static SENSOR_DEVICE_ATTR_RO(in1_input, ltc4260_value, LTC4260_SOURCE); static SENSOR_DEVICE_ATTR_RO(in2_input, ltc4260_value, LTC4260_ADIN); /* * Voltage alarms * UV/OV faults are associated with the input voltage, and the POWER BAD and * FET SHORT faults are associated with the output voltage. */ static SENSOR_DEVICE_ATTR_RO(in1_min_alarm, ltc4260_bool, FAULT_UV); static SENSOR_DEVICE_ATTR_RO(in1_max_alarm, ltc4260_bool, FAULT_OV); static SENSOR_DEVICE_ATTR_RO(in2_alarm, ltc4260_bool, FAULT_POWER_BAD | FAULT_FET_SHORT); /* Current (via sense resistor) */ static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc4260_value, LTC4260_SENSE); /* Overcurrent alarm */ static SENSOR_DEVICE_ATTR_RO(curr1_max_alarm, ltc4260_bool, FAULT_OC); static struct attribute *ltc4260_attrs[] = { &sensor_dev_attr_in1_input.dev_attr.attr, &sensor_dev_attr_in1_min_alarm.dev_attr.attr, &sensor_dev_attr_in1_max_alarm.dev_attr.attr, &sensor_dev_attr_in2_input.dev_attr.attr, &sensor_dev_attr_in2_alarm.dev_attr.attr, &sensor_dev_attr_curr1_input.dev_attr.attr, &sensor_dev_attr_curr1_max_alarm.dev_attr.attr, NULL, }; ATTRIBUTE_GROUPS(ltc4260); static const struct regmap_config ltc4260_regmap_config = { .reg_bits = 8, .val_bits = 8, .max_register = LTC4260_ADIN, }; static int ltc4260_probe(struct i2c_client *client) { struct device *dev = &client->dev; struct device *hwmon_dev; struct regmap *regmap; regmap = devm_regmap_init_i2c(client, <c4260_regmap_config); if (IS_ERR(regmap)) { dev_err(dev, "failed to allocate register map\n"); return PTR_ERR(regmap); } /* Clear faults */ regmap_write(regmap, LTC4260_FAULT, 0x00); hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, regmap, ltc4260_groups); return PTR_ERR_OR_ZERO(hwmon_dev); } static const struct i2c_device_id ltc4260_id[] = { {"ltc4260", 0}, { } }; MODULE_DEVICE_TABLE(i2c, ltc4260_id); static struct i2c_driver ltc4260_driver = { .driver = { .name = "ltc4260", }, .probe = ltc4260_probe, .id_table = ltc4260_id, }; module_i2c_driver(ltc4260_driver); MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>"); MODULE_DESCRIPTION("LTC4260 driver"); MODULE_LICENSE("GPL"); |