110 lines
3.2 KiB
C
110 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Hardware monitoring driver for Analog Devices MAX20830
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*
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* Copyright (C) 2026 Analog Devices, Inc.
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*/
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#include <linux/errno.h>
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#include <linux/i2c.h>
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#include <linux/module.h>
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#include <linux/string.h>
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#include "pmbus.h"
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#define MAX20830_IC_DEVICE_ID_LENGTH 9
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static struct pmbus_driver_info max20830_info = {
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.pages = 1,
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.format[PSC_VOLTAGE_IN] = linear,
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.format[PSC_VOLTAGE_OUT] = linear,
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.format[PSC_CURRENT_OUT] = linear,
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.format[PSC_TEMPERATURE] = linear,
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.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
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PMBUS_HAVE_TEMP |
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PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
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PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
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};
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static int max20830_probe(struct i2c_client *client)
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{
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u8 buf[I2C_SMBUS_BLOCK_MAX + 1] = {};
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int ret;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_BLOCK_DATA) &&
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!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
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return -ENODEV;
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/*
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* Use i2c_smbus_read_block_data() if supported, otherwise fall back
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* to i2c_smbus_read_i2c_block_data() to support I2C controllers
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* which do not support SMBus block reads.
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*/
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if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_BLOCK_DATA)) {
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/* Reads 9 Data bytes from MAX20830 */
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ret = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, buf);
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if (ret < 0)
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return dev_err_probe(&client->dev, ret,
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"Failed to read IC_DEVICE_ID\n");
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} else {
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/* Reads 1 length byte + 9 Data bytes from MAX20830 */
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ret = i2c_smbus_read_i2c_block_data(client, PMBUS_IC_DEVICE_ID,
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MAX20830_IC_DEVICE_ID_LENGTH + 1,
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buf);
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if (ret < 0)
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return dev_err_probe(&client->dev, ret,
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"Failed to read IC_DEVICE_ID\n");
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/*
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* Moves data forward, removing the length byte, this is to
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* match the format of i2c_smbus_read_block_data().
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* Also adjust return value to reflect length byte removal.
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*/
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memmove(buf, buf + 1, MAX20830_IC_DEVICE_ID_LENGTH);
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ret = ret - 1;
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}
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/*
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* MAX20830 IC_DEVICE_ID sends string data "MAX20830\0".
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* Return value should at least be 9 bytes of data.
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*/
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if (ret < MAX20830_IC_DEVICE_ID_LENGTH)
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return dev_err_probe(&client->dev, -ENODEV,
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"IC_DEVICE_ID too short: expected at least 9 bytes, got %d\n",
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ret);
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/* 9 bytes of data, buf[0]-buf[7] = "MAX20830", buf[8] = '\0' */
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buf[MAX20830_IC_DEVICE_ID_LENGTH - 1] = '\0';
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if (strncmp(buf, "MAX20830", MAX20830_IC_DEVICE_ID_LENGTH - 1))
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return dev_err_probe(&client->dev, -ENODEV,
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"Unsupported device: '%s'\n", buf);
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return pmbus_do_probe(client, &max20830_info);
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}
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static const struct i2c_device_id max20830_id[] = {
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{"max20830"},
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, max20830_id);
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static const struct of_device_id max20830_of_match[] = {
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{ .compatible = "adi,max20830" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, max20830_of_match);
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static struct i2c_driver max20830_driver = {
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.driver = {
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.name = "max20830",
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.of_match_table = max20830_of_match,
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},
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.probe = max20830_probe,
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.id_table = max20830_id,
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};
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module_i2c_driver(max20830_driver);
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MODULE_AUTHOR("Alexis Czezar Torreno <alexisczezar.torreno@analog.com>");
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MODULE_DESCRIPTION("PMBus driver for Analog Devices MAX20830");
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MODULE_LICENSE("GPL");
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MODULE_IMPORT_NS("PMBUS");
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