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- // 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 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)
- {
- 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_new = adm1177_probe,
- .id_table = adm1177_id,
- };
- module_i2c_driver(adm1177_driver);
- MODULE_AUTHOR("Beniamin Bia <[email protected]>");
- MODULE_AUTHOR("Michael Hennerich <[email protected]>");
- MODULE_DESCRIPTION("Analog Devices ADM1177 ADC driver");
- MODULE_LICENSE("GPL v2");
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