diff options
Diffstat (limited to 'drivers/hwmon/adm1177.c')
| -rw-r--r-- | drivers/hwmon/adm1177.c | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/drivers/hwmon/adm1177.c b/drivers/hwmon/adm1177.c new file mode 100644 index 000000000000..d314223a404a --- /dev/null +++ b/drivers/hwmon/adm1177.c @@ -0,0 +1,288 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ADM1177 Hot Swap Controller and Digital Power Monitor with Soft Start Pin + * + * Copyright 2015-2019 Analog Devices Inc. + */ + +#include <linux/bits.h> +#include <linux/device.h> +#include <linux/hwmon.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/regulator/consumer.h> + +/* Command Byte Operations */ +#define ADM1177_CMD_V_CONT BIT(0) +#define ADM1177_CMD_I_CONT BIT(2) +#define ADM1177_CMD_VRANGE BIT(4) + +/* Extended Register */ +#define ADM1177_REG_ALERT_TH 2 + +#define ADM1177_BITS 12 + +/** + * struct adm1177_state - driver instance specific data + * @client pointer to i2c client + * @reg regulator info for the the power supply of the device + * @r_sense_uohm current sense resistor value + * @alert_threshold_ua current limit for shutdown + * @vrange_high internal voltage divider + */ +struct adm1177_state { + struct i2c_client *client; + struct regulator *reg; + u32 r_sense_uohm; + u32 alert_threshold_ua; + bool vrange_high; +}; + +static int adm1177_read_raw(struct adm1177_state *st, u8 num, u8 *data) +{ + return i2c_master_recv(st->client, data, num); +} + +static int adm1177_write_cmd(struct adm1177_state *st, u8 cmd) +{ + return i2c_smbus_write_byte(st->client, cmd); +} + +static int adm1177_write_alert_thr(struct adm1177_state *st, + u32 alert_threshold_ua) +{ + u64 val; + int ret; + + val = 0xFFULL * alert_threshold_ua * st->r_sense_uohm; + val = div_u64(val, 105840000U); + val = div_u64(val, 1000U); + if (val > 0xFF) + val = 0xFF; + + ret = i2c_smbus_write_byte_data(st->client, ADM1177_REG_ALERT_TH, + val); + if (ret) + return ret; + + st->alert_threshold_ua = alert_threshold_ua; + return 0; +} + +static int adm1177_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + struct adm1177_state *st = dev_get_drvdata(dev); + u8 data[3]; + long dummy; + int ret; + + switch (type) { + case hwmon_curr: + switch (attr) { + case hwmon_curr_input: + ret = adm1177_read_raw(st, 3, data); + if (ret < 0) + return ret; + dummy = (data[1] << 4) | (data[2] & 0xF); + /* + * convert to milliamperes + * ((105.84mV / 4096) x raw) / senseResistor(ohm) + */ + *val = div_u64((105840000ull * dummy), + 4096 * st->r_sense_uohm); + return 0; + case hwmon_curr_max_alarm: + *val = st->alert_threshold_ua; + return 0; + default: + return -EOPNOTSUPP; + } + case hwmon_in: + ret = adm1177_read_raw(st, 3, data); + if (ret < 0) + return ret; + dummy = (data[0] << 4) | (data[2] >> 4); + /* + * convert to millivolts based on resistor devision + * (V_fullscale / 4096) * raw + */ + if (st->vrange_high) + dummy *= 26350; + else + dummy *= 6650; + + *val = DIV_ROUND_CLOSEST(dummy, 4096); + return 0; + default: + return -EOPNOTSUPP; + } +} + +static int adm1177_write(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long val) +{ + struct adm1177_state *st = dev_get_drvdata(dev); + + switch (type) { + case hwmon_curr: + switch (attr) { + case hwmon_curr_max_alarm: + adm1177_write_alert_thr(st, val); + return 0; + default: + return -EOPNOTSUPP; + } + default: + return -EOPNOTSUPP; + } +} + +static umode_t adm1177_is_visible(const void *data, + enum hwmon_sensor_types type, + u32 attr, int channel) +{ + const struct adm1177_state *st = data; + + switch (type) { + case hwmon_in: + switch (attr) { + case hwmon_in_input: + return 0444; + } + break; + case hwmon_curr: + switch (attr) { + case hwmon_curr_input: + if (st->r_sense_uohm) + return 0444; + return 0; + case hwmon_curr_max_alarm: + if (st->r_sense_uohm) + return 0644; + return 0; + } + break; + default: + break; + } + return 0; +} + +static const struct hwmon_channel_info *adm1177_info[] = { + HWMON_CHANNEL_INFO(curr, + HWMON_C_INPUT | HWMON_C_MAX_ALARM), + HWMON_CHANNEL_INFO(in, + HWMON_I_INPUT), + NULL +}; + +static const struct hwmon_ops adm1177_hwmon_ops = { + .is_visible = adm1177_is_visible, + .read = adm1177_read, + .write = adm1177_write, +}; + +static const struct hwmon_chip_info adm1177_chip_info = { + .ops = &adm1177_hwmon_ops, + .info = adm1177_info, +}; + +static void adm1177_remove(void *data) +{ + struct adm1177_state *st = data; + + regulator_disable(st->reg); +} + +static int adm1177_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + struct device *hwmon_dev; + struct adm1177_state *st; + u32 alert_threshold_ua; + int ret; + + st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL); + if (!st) + return -ENOMEM; + + st->client = client; + + st->reg = devm_regulator_get_optional(&client->dev, "vref"); + if (IS_ERR(st->reg)) { + if (PTR_ERR(st->reg) == -EPROBE_DEFER) + return -EPROBE_DEFER; + + st->reg = NULL; + } else { + ret = regulator_enable(st->reg); + if (ret) + return ret; + ret = devm_add_action_or_reset(&client->dev, adm1177_remove, + st); + if (ret) + return ret; + } + + if (device_property_read_u32(dev, "shunt-resistor-micro-ohms", + &st->r_sense_uohm)) + st->r_sense_uohm = 0; + if (device_property_read_u32(dev, "adi,shutdown-threshold-microamp", + &alert_threshold_ua)) { + if (st->r_sense_uohm) + /* + * set maximum default value from datasheet based on + * shunt-resistor + */ + alert_threshold_ua = div_u64(105840000000, + st->r_sense_uohm); + else + alert_threshold_ua = 0; + } + st->vrange_high = device_property_read_bool(dev, + "adi,vrange-high-enable"); + if (alert_threshold_ua && st->r_sense_uohm) + adm1177_write_alert_thr(st, alert_threshold_ua); + + ret = adm1177_write_cmd(st, ADM1177_CMD_V_CONT | + ADM1177_CMD_I_CONT | + (st->vrange_high ? 0 : ADM1177_CMD_VRANGE)); + if (ret) + return ret; + + hwmon_dev = + devm_hwmon_device_register_with_info(dev, client->name, st, + &adm1177_chip_info, NULL); + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static const struct i2c_device_id adm1177_id[] = { + {"adm1177", 0}, + {} +}; +MODULE_DEVICE_TABLE(i2c, adm1177_id); + +static const struct of_device_id adm1177_dt_ids[] = { + { .compatible = "adi,adm1177" }, + {}, +}; +MODULE_DEVICE_TABLE(of, adm1177_dt_ids); + +static struct i2c_driver adm1177_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = "adm1177", + .of_match_table = adm1177_dt_ids, + }, + .probe = adm1177_probe, + .id_table = adm1177_id, +}; +module_i2c_driver(adm1177_driver); + +MODULE_AUTHOR("Beniamin Bia <beniamin.bia@analog.com>"); +MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>"); +MODULE_DESCRIPTION("Analog Devices ADM1177 ADC driver"); +MODULE_LICENSE("GPL v2"); |