// SPDX-License-Identifier: GPL-2.0-or-later /* * powr1220.c - Driver for the Lattice POWR1220 programmable power supply * and monitor. Users can read all ADC inputs along with their labels * using the sysfs nodes. * * Copyright (c) 2014 Echo360 https://www.echo360.com * Scott Kanowitz <skanowitz@echo360.com> <scott.kanowitz@gmail.com> */ #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/jiffies.h> #include <linux/i2c.h> #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> #include <linux/err.h> #include <linux/mutex.h> #include <linux/delay.h> #define ADC_STEP_MV 2 #define ADC_MAX_LOW_MEASUREMENT_MV 2000 enum powr1xxx_chips { powr1014, powr1220 }; enum powr1220_regs { VMON_STATUS0, VMON_STATUS1, VMON_STATUS2, OUTPUT_STATUS0, OUTPUT_STATUS1, OUTPUT_STATUS2, INPUT_STATUS, ADC_VALUE_LOW, ADC_VALUE_HIGH, ADC_MUX, UES_BYTE0, UES_BYTE1, UES_BYTE2, UES_BYTE3, GP_OUTPUT1, GP_OUTPUT2, GP_OUTPUT3, INPUT_VALUE, RESET, TRIM1_TRIM, TRIM2_TRIM, TRIM3_TRIM, TRIM4_TRIM, TRIM5_TRIM, TRIM6_TRIM, TRIM7_TRIM, TRIM8_TRIM, MAX_POWR1220_REGS }; enum powr1220_adc_values { VMON1, VMON2, VMON3, VMON4, VMON5, VMON6, VMON7, VMON8, VMON9, VMON10, VMON11, VMON12, VCCA, VCCINP, MAX_POWR1220_ADC_VALUES }; struct powr1220_data { struct i2c_client *client; struct mutex update_lock; u8 max_channels; bool adc_valid[MAX_POWR1220_ADC_VALUES]; /* the next value is in jiffies */ unsigned long adc_last_updated[MAX_POWR1220_ADC_VALUES]; /* values */ int adc_maxes[MAX_POWR1220_ADC_VALUES]; int adc_values[MAX_POWR1220_ADC_VALUES]; }; static const char * const input_names[] = { [VMON1] = "vmon1", [VMON2] = "vmon2", [VMON3] = "vmon3", [VMON4] = "vmon4", [VMON5] = "vmon5", [VMON6] = "vmon6", [VMON7] = "vmon7", [VMON8] = "vmon8", [VMON9] = "vmon9", [VMON10] = "vmon10", [VMON11] = "vmon11", [VMON12] = "vmon12", [VCCA] = "vcca", [VCCINP] = "vccinp", }; /* Reads the specified ADC channel */ static int powr1220_read_adc(struct device *dev, int ch_num) { struct powr1220_data *data = dev_get_drvdata(dev); int reading; int result; int adc_range = 0; mutex_lock(&data->update_lock); if (time_after(jiffies, data->adc_last_updated[ch_num] + HZ) || !data->adc_valid[ch_num]) { /* * figure out if we need to use the attenuator for * high inputs or inputs that we don't yet have a measurement * for. We dynamically set the attenuator depending on the * max reading. */ if (data->adc_maxes[ch_num] > ADC_MAX_LOW_MEASUREMENT_MV || data->adc_maxes[ch_num] == 0) adc_range = 1 << 4; /* set the attenuator and mux */ result = i2c_smbus_write_byte_data(data->client, ADC_MUX, adc_range | ch_num); if (result) goto exit; /* * wait at least Tconvert time (200 us) for the * conversion to complete */ udelay(200); /* get the ADC reading */ result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_LOW); if (result < 0) goto exit; reading = result >> 4; /* get the upper half of the reading */ result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_HIGH); if (result < 0) goto exit; reading |= result << 4; /* now convert the reading to a voltage */ reading *= ADC_STEP_MV; data->adc_values[ch_num] = reading; data->adc_valid[ch_num] = true; data->adc_last_updated[ch_num] = jiffies; result = reading; if (reading > data->adc_maxes[ch_num]) data->adc_maxes[ch_num] = reading; } else { result = data->adc_values[ch_num]; } exit: mutex_unlock(&data->update_lock); return result; } static umode_t powr1220_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel) { struct powr1220_data *chip_data = (struct powr1220_data *)data; if (channel >= chip_data->max_channels) return 0; switch (type) { case hwmon_in: switch (attr) { case hwmon_in_input: case hwmon_in_highest: case hwmon_in_label: return 0444; default: break; } break; default: break; } return 0; } static int powr1220_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, const char **str) { switch (type) { case hwmon_in: switch (attr) { case hwmon_in_label: *str = input_names[channel]; return 0; default: return -EOPNOTSUPP; } break; default: return -EOPNOTSUPP; } return -EOPNOTSUPP; } static int powr1220_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val) { struct powr1220_data *data = dev_get_drvdata(dev); int ret; switch (type) { case hwmon_in: switch (attr) { case hwmon_in_input: ret = powr1220_read_adc(dev, channel); if (ret < 0) return ret; *val = ret; break; case hwmon_in_highest: *val = data->adc_maxes[channel]; break; default: return -EOPNOTSUPP; } break; default: return -EOPNOTSUPP; } return 0; } static const struct hwmon_channel_info *powr1220_info[] = { HWMON_CHANNEL_INFO(in, HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL), NULL }; static const struct hwmon_ops powr1220_hwmon_ops = { .read = powr1220_read, .read_string = powr1220_read_string, .is_visible = powr1220_is_visible, }; static const struct hwmon_chip_info powr1220_chip_info = { .ops = &powr1220_hwmon_ops, .info = powr1220_info, }; static const struct i2c_device_id powr1220_ids[]; static int powr1220_probe(struct i2c_client *client) { struct powr1220_data *data; struct device *hwmon_dev; if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) return -ENODEV; data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; switch (i2c_match_id(powr1220_ids, client)->driver_data) { case powr1014: data->max_channels = 10; break; default: data->max_channels = 12; break; } mutex_init(&data->update_lock); data->client = client; hwmon_dev = devm_hwmon_device_register_with_info(&client->dev, client->name, data, &powr1220_chip_info, NULL); return PTR_ERR_OR_ZERO(hwmon_dev); } static const struct i2c_device_id powr1220_ids[] = { { "powr1014", powr1014, }, { "powr1220", powr1220, }, { } }; MODULE_DEVICE_TABLE(i2c, powr1220_ids); static struct i2c_driver powr1220_driver = { .class = I2C_CLASS_HWMON, .driver = { .name = "powr1220", }, .probe_new = powr1220_probe, .id_table = powr1220_ids, }; module_i2c_driver(powr1220_driver); MODULE_AUTHOR("Scott Kanowitz"); MODULE_DESCRIPTION("POWR1220 driver"); MODULE_LICENSE("GPL");