1// SPDX-License-Identifier: GPL-2.0 2/* 3 * ADM1177 Hot Swap Controller and Digital Power Monitor with Soft Start Pin 4 * 5 * Copyright 2015-2019 Analog Devices Inc. 6 */ 7 8#include <linux/bits.h> 9#include <linux/device.h> 10#include <linux/hwmon.h> 11#include <linux/i2c.h> 12#include <linux/init.h> 13#include <linux/module.h> 14#include <linux/regulator/consumer.h> 15 16/* Command Byte Operations */ 17#define ADM1177_CMD_V_CONT BIT(0) 18#define ADM1177_CMD_I_CONT BIT(2) 19#define ADM1177_CMD_VRANGE BIT(4) 20 21/* Extended Register */ 22#define ADM1177_REG_ALERT_TH 2 23 24#define ADM1177_BITS 12 25 26/** 27 * struct adm1177_state - driver instance specific data 28 * @client: pointer to i2c client 29 * @r_sense_uohm: current sense resistor value 30 * @alert_threshold_ua: current limit for shutdown 31 * @vrange_high: internal voltage divider 32 */ 33struct adm1177_state { 34 struct i2c_client *client; 35 u32 r_sense_uohm; 36 u32 alert_threshold_ua; 37 bool vrange_high; 38}; 39 40static int adm1177_read_raw(struct adm1177_state *st, u8 num, u8 *data) 41{ 42 return i2c_master_recv(st->client, data, num); 43} 44 45static int adm1177_write_cmd(struct adm1177_state *st, u8 cmd) 46{ 47 return i2c_smbus_write_byte(st->client, cmd); 48} 49 50static int adm1177_write_alert_thr(struct adm1177_state *st, 51 u32 alert_threshold_ua) 52{ 53 u64 val; 54 int ret; 55 56 val = 0xFFULL * alert_threshold_ua * st->r_sense_uohm; 57 val = div_u64(val, 105840000U); 58 val = div_u64(val, 1000U); 59 if (val > 0xFF) 60 val = 0xFF; 61 62 ret = i2c_smbus_write_byte_data(st->client, ADM1177_REG_ALERT_TH, 63 val); 64 if (ret) 65 return ret; 66 67 st->alert_threshold_ua = alert_threshold_ua; 68 return 0; 69} 70 71static int adm1177_read(struct device *dev, enum hwmon_sensor_types type, 72 u32 attr, int channel, long *val) 73{ 74 struct adm1177_state *st = dev_get_drvdata(dev); 75 u8 data[3]; 76 long dummy; 77 int ret; 78 79 switch (type) { 80 case hwmon_curr: 81 switch (attr) { 82 case hwmon_curr_input: 83 ret = adm1177_read_raw(st, 3, data); 84 if (ret < 0) 85 return ret; 86 dummy = (data[1] << 4) | (data[2] & 0xF); 87 /* 88 * convert to milliamperes 89 * ((105.84mV / 4096) x raw) / senseResistor(ohm) 90 */ 91 *val = div_u64((105840000ull * dummy), 92 4096 * st->r_sense_uohm); 93 return 0; 94 case hwmon_curr_max_alarm: 95 *val = st->alert_threshold_ua; 96 return 0; 97 default: 98 return -EOPNOTSUPP; 99 } 100 case hwmon_in: 101 ret = adm1177_read_raw(st, 3, data); 102 if (ret < 0) 103 return ret; 104 dummy = (data[0] << 4) | (data[2] >> 4); 105 /* 106 * convert to millivolts based on resistor devision 107 * (V_fullscale / 4096) * raw 108 */ 109 if (st->vrange_high) 110 dummy *= 26350; 111 else 112 dummy *= 6650; 113 114 *val = DIV_ROUND_CLOSEST(dummy, 4096); 115 return 0; 116 default: 117 return -EOPNOTSUPP; 118 } 119} 120 121static int adm1177_write(struct device *dev, enum hwmon_sensor_types type, 122 u32 attr, int channel, long val) 123{ 124 struct adm1177_state *st = dev_get_drvdata(dev); 125 126 switch (type) { 127 case hwmon_curr: 128 switch (attr) { 129 case hwmon_curr_max_alarm: 130 adm1177_write_alert_thr(st, val); 131 return 0; 132 default: 133 return -EOPNOTSUPP; 134 } 135 default: 136 return -EOPNOTSUPP; 137 } 138} 139 140static umode_t adm1177_is_visible(const void *data, 141 enum hwmon_sensor_types type, 142 u32 attr, int channel) 143{ 144 const struct adm1177_state *st = data; 145 146 switch (type) { 147 case hwmon_in: 148 switch (attr) { 149 case hwmon_in_input: 150 return 0444; 151 } 152 break; 153 case hwmon_curr: 154 switch (attr) { 155 case hwmon_curr_input: 156 if (st->r_sense_uohm) 157 return 0444; 158 return 0; 159 case hwmon_curr_max_alarm: 160 if (st->r_sense_uohm) 161 return 0644; 162 return 0; 163 } 164 break; 165 default: 166 break; 167 } 168 return 0; 169} 170 171static const struct hwmon_channel_info * const adm1177_info[] = { 172 HWMON_CHANNEL_INFO(curr, 173 HWMON_C_INPUT | HWMON_C_MAX_ALARM), 174 HWMON_CHANNEL_INFO(in, 175 HWMON_I_INPUT), 176 NULL 177}; 178 179static const struct hwmon_ops adm1177_hwmon_ops = { 180 .is_visible = adm1177_is_visible, 181 .read = adm1177_read, 182 .write = adm1177_write, 183}; 184 185static const struct hwmon_chip_info adm1177_chip_info = { 186 .ops = &adm1177_hwmon_ops, 187 .info = adm1177_info, 188}; 189 190static int adm1177_probe(struct i2c_client *client) 191{ 192 struct device *dev = &client->dev; 193 struct device *hwmon_dev; 194 struct adm1177_state *st; 195 u32 alert_threshold_ua; 196 int ret; 197 198 st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL); 199 if (!st) 200 return -ENOMEM; 201 202 st->client = client; 203 204 ret = devm_regulator_get_enable_optional(&client->dev, "vref"); 205 if (ret == -EPROBE_DEFER) 206 return -EPROBE_DEFER; 207 208 if (device_property_read_u32(dev, "shunt-resistor-micro-ohms", 209 &st->r_sense_uohm)) 210 st->r_sense_uohm = 0; 211 if (device_property_read_u32(dev, "adi,shutdown-threshold-microamp", 212 &alert_threshold_ua)) { 213 if (st->r_sense_uohm) 214 /* 215 * set maximum default value from datasheet based on 216 * shunt-resistor 217 */ 218 alert_threshold_ua = div_u64(105840000000, 219 st->r_sense_uohm); 220 else 221 alert_threshold_ua = 0; 222 } 223 st->vrange_high = device_property_read_bool(dev, 224 "adi,vrange-high-enable"); 225 if (alert_threshold_ua && st->r_sense_uohm) 226 adm1177_write_alert_thr(st, alert_threshold_ua); 227 228 ret = adm1177_write_cmd(st, ADM1177_CMD_V_CONT | 229 ADM1177_CMD_I_CONT | 230 (st->vrange_high ? 0 : ADM1177_CMD_VRANGE)); 231 if (ret) 232 return ret; 233 234 hwmon_dev = 235 devm_hwmon_device_register_with_info(dev, client->name, st, 236 &adm1177_chip_info, NULL); 237 return PTR_ERR_OR_ZERO(hwmon_dev); 238} 239 240static const struct i2c_device_id adm1177_id[] = { 241 {"adm1177", 0}, 242 {} 243}; 244MODULE_DEVICE_TABLE(i2c, adm1177_id); 245 246static const struct of_device_id adm1177_dt_ids[] = { 247 { .compatible = "adi,adm1177" }, 248 {}, 249}; 250MODULE_DEVICE_TABLE(of, adm1177_dt_ids); 251 252static struct i2c_driver adm1177_driver = { 253 .class = I2C_CLASS_HWMON, 254 .driver = { 255 .name = "adm1177", 256 .of_match_table = adm1177_dt_ids, 257 }, 258 .probe = adm1177_probe, 259 .id_table = adm1177_id, 260}; 261module_i2c_driver(adm1177_driver); 262 263MODULE_AUTHOR("Beniamin Bia <beniamin.bia@analog.com>"); 264MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>"); 265MODULE_DESCRIPTION("Analog Devices ADM1177 ADC driver"); 266MODULE_LICENSE("GPL v2"); 267