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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 | // SPDX-License-Identifier: GPL-2.0-or-later /* * Driver for Linear Technology LTC4222 Dual 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/bitops.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 LTC4222_CONTROL1 0xd0 #define LTC4222_ALERT1 0xd1 #define LTC4222_STATUS1 0xd2 #define LTC4222_FAULT1 0xd3 #define LTC4222_CONTROL2 0xd4 #define LTC4222_ALERT2 0xd5 #define LTC4222_STATUS2 0xd6 #define LTC4222_FAULT2 0xd7 #define LTC4222_SOURCE1 0xd8 #define LTC4222_SOURCE2 0xda #define LTC4222_ADIN1 0xdc #define LTC4222_ADIN2 0xde #define LTC4222_SENSE1 0xe0 #define LTC4222_SENSE2 0xe2 #define LTC4222_ADC_CONTROL 0xe4 /* * Fault register bits */ #define FAULT_OV BIT(0) #define FAULT_UV BIT(1) #define FAULT_OC BIT(2) #define FAULT_POWER_BAD BIT(3) #define FAULT_FET_BAD BIT(5) /* Return the voltage from the given register in mV or mA */ static int ltc4222_get_value(struct device *dev, u8 reg) { struct regmap *regmap = dev_get_drvdata(dev); unsigned int val; u8 buf[2]; int ret; ret = regmap_bulk_read(regmap, reg, buf, 2); if (ret < 0) return ret; val = ((buf[0] << 8) + buf[1]) >> 6; switch (reg) { case LTC4222_ADIN1: case LTC4222_ADIN2: /* 1.25 mV resolution. Convert to mV. */ val = DIV_ROUND_CLOSEST(val * 5, 4); break; case LTC4222_SOURCE1: case LTC4222_SOURCE2: /* 31.25 mV resolution. Convert to mV. */ val = DIV_ROUND_CLOSEST(val * 125, 4); break; case LTC4222_SENSE1: case LTC4222_SENSE2: /* * 62.5 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 = DIV_ROUND_CLOSEST(val * 125, 2); break; default: return -EINVAL; } return val; } static ssize_t ltc4222_value_show(struct device *dev, struct device_attribute *da, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); int value; value = ltc4222_get_value(dev, attr->index); if (value < 0) return value; return sysfs_emit(buf, "%d\n", value); } static ssize_t ltc4222_bool_show(struct device *dev, struct device_attribute *da, char *buf) { struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da); struct regmap *regmap = dev_get_drvdata(dev); unsigned int fault; int ret; ret = regmap_read(regmap, attr->nr, &fault); if (ret < 0) return ret; fault &= attr->index; if (fault) /* Clear reported faults in chip register */ regmap_update_bits(regmap, attr->nr, attr->index, 0); return sysfs_emit(buf, "%d\n", !!fault); } /* Voltages */ static SENSOR_DEVICE_ATTR_RO(in1_input, ltc4222_value, LTC4222_SOURCE1); static SENSOR_DEVICE_ATTR_RO(in2_input, ltc4222_value, LTC4222_ADIN1); static SENSOR_DEVICE_ATTR_RO(in3_input, ltc4222_value, LTC4222_SOURCE2); static SENSOR_DEVICE_ATTR_RO(in4_input, ltc4222_value, LTC4222_ADIN2); /* * Voltage alarms * UV/OV faults are associated with the input voltage, and power bad and fet * faults are associated with the output voltage. */ static SENSOR_DEVICE_ATTR_2_RO(in1_min_alarm, ltc4222_bool, LTC4222_FAULT1, FAULT_UV); static SENSOR_DEVICE_ATTR_2_RO(in1_max_alarm, ltc4222_bool, LTC4222_FAULT1, FAULT_OV); static SENSOR_DEVICE_ATTR_2_RO(in2_alarm, ltc4222_bool, LTC4222_FAULT1, FAULT_POWER_BAD | FAULT_FET_BAD); static SENSOR_DEVICE_ATTR_2_RO(in3_min_alarm, ltc4222_bool, LTC4222_FAULT2, FAULT_UV); static SENSOR_DEVICE_ATTR_2_RO(in3_max_alarm, ltc4222_bool, LTC4222_FAULT2, FAULT_OV); static SENSOR_DEVICE_ATTR_2_RO(in4_alarm, ltc4222_bool, LTC4222_FAULT2, FAULT_POWER_BAD | FAULT_FET_BAD); /* Current (via sense resistor) */ static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc4222_value, LTC4222_SENSE1); static SENSOR_DEVICE_ATTR_RO(curr2_input, ltc4222_value, LTC4222_SENSE2); /* Overcurrent alarm */ static SENSOR_DEVICE_ATTR_2_RO(curr1_max_alarm, ltc4222_bool, LTC4222_FAULT1, FAULT_OC); static SENSOR_DEVICE_ATTR_2_RO(curr2_max_alarm, ltc4222_bool, LTC4222_FAULT2, FAULT_OC); static struct attribute *ltc4222_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_in3_input.dev_attr.attr, &sensor_dev_attr_in3_min_alarm.dev_attr.attr, &sensor_dev_attr_in3_max_alarm.dev_attr.attr, &sensor_dev_attr_in4_input.dev_attr.attr, &sensor_dev_attr_in4_alarm.dev_attr.attr, &sensor_dev_attr_curr1_input.dev_attr.attr, &sensor_dev_attr_curr1_max_alarm.dev_attr.attr, &sensor_dev_attr_curr2_input.dev_attr.attr, &sensor_dev_attr_curr2_max_alarm.dev_attr.attr, NULL, }; ATTRIBUTE_GROUPS(ltc4222); static const struct regmap_config ltc4222_regmap_config = { .reg_bits = 8, .val_bits = 8, .max_register = LTC4222_ADC_CONTROL, }; static int ltc4222_probe(struct i2c_client *client) { struct device *dev = &client->dev; struct device *hwmon_dev; struct regmap *regmap; regmap = devm_regmap_init_i2c(client, <c4222_regmap_config); if (IS_ERR(regmap)) { dev_err(dev, "failed to allocate register map\n"); return PTR_ERR(regmap); } /* Clear faults */ regmap_write(regmap, LTC4222_FAULT1, 0x00); regmap_write(regmap, LTC4222_FAULT2, 0x00); hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, regmap, ltc4222_groups); return PTR_ERR_OR_ZERO(hwmon_dev); } static const struct i2c_device_id ltc4222_id[] = { {"ltc4222", 0}, { } }; MODULE_DEVICE_TABLE(i2c, ltc4222_id); static struct i2c_driver ltc4222_driver = { .driver = { .name = "ltc4222", }, .probe = ltc4222_probe, .id_table = ltc4222_id, }; module_i2c_driver(ltc4222_driver); MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>"); MODULE_DESCRIPTION("LTC4222 driver"); MODULE_LICENSE("GPL"); |