drivers/hwmon/pmbus/lt3074.c

Source file repositories/reference/linux-study-clean/drivers/hwmon/pmbus/lt3074.c

File Facts

System
Linux kernel
Corpus path
drivers/hwmon/pmbus/lt3074.c
Extension
.c
Size
3302 bytes
Lines
123
Domain
Driver Families
Bucket
drivers/hwmon
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * Hardware monitoring driver for Analog Devices LT3074
 *
 * Copyright (C) 2025 Analog Devices, Inc.
 */
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>

#include "pmbus.h"

#define LT3074_MFR_READ_VBIAS			0xc6
#define LT3074_MFR_BIAS_OV_WARN_LIMIT		0xc7
#define LT3074_MFR_BIAS_UV_WARN_LIMIT		0xc8
#define LT3074_MFR_SPECIAL_ID			0xe7

#define LT3074_SPECIAL_ID_VALUE			0x1c1d

static const struct regulator_desc __maybe_unused lt3074_reg_desc[] = {
	PMBUS_REGULATOR_ONE("regulator"),
};

static int lt3074_read_word_data(struct i2c_client *client, int page,
				 int phase, int reg)
{
	switch (reg) {
	case PMBUS_VIRT_READ_VMON:
		return pmbus_read_word_data(client, page, phase,
					   LT3074_MFR_READ_VBIAS);
	case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
		return pmbus_read_word_data(client, page, phase,
					   LT3074_MFR_BIAS_UV_WARN_LIMIT);
	case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
		return pmbus_read_word_data(client, page, phase,
					   LT3074_MFR_BIAS_OV_WARN_LIMIT);
	default:
		return -ENODATA;
	}
}

static int lt3074_write_word_data(struct i2c_client *client, int page,
				  int reg, u16 word)
{
	switch (reg) {
	case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
		return pmbus_write_word_data(client, 0,
					    LT3074_MFR_BIAS_UV_WARN_LIMIT,
					    word);
	case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
		return pmbus_write_word_data(client, 0,
					    LT3074_MFR_BIAS_OV_WARN_LIMIT,
					    word);
	default:
		return -ENODATA;
	}
}

static struct pmbus_driver_info lt3074_info = {
	.pages = 1,
	.format[PSC_VOLTAGE_IN] = linear,
	.format[PSC_VOLTAGE_OUT] = linear,
	.format[PSC_CURRENT_OUT] = linear,
	.format[PSC_TEMPERATURE] = linear,
	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
		   PMBUS_HAVE_TEMP | PMBUS_HAVE_VMON |
		   PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
		   PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
	.read_word_data = lt3074_read_word_data,
	.write_word_data = lt3074_write_word_data,
#if IS_ENABLED(CONFIG_SENSORS_LT3074_REGULATOR)
	.num_regulators = 1,
	.reg_desc = lt3074_reg_desc,
#endif
};

static int lt3074_probe(struct i2c_client *client)
{
	int ret;
	struct device *dev = &client->dev;

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_READ_WORD_DATA))
		return -ENODEV;

	ret = i2c_smbus_read_word_data(client, LT3074_MFR_SPECIAL_ID);
	if (ret < 0)
		return dev_err_probe(dev, ret, "Failed to read ID\n");

Annotation

Implementation Notes