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8d28cd1b1f
LTC3815 is a Monolithic Synchronous DC/DC Step-Down Converter. Cc: Michael Jones <mike@proclivis.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
215 lines
5.3 KiB
C
215 lines
5.3 KiB
C
/*
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* Hardware monitoring driver for LTC3815
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*
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* Copyright (c) 2015 Linear Technology
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* Copyright (c) 2015 Guenter Roeck
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/init.h>
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#include <linux/jiffies.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include "pmbus.h"
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#define LTC3815_MFR_IOUT_PEAK 0xd7
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#define LTC3815_MFR_VOUT_PEAK 0xdd
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#define LTC3815_MFR_VIN_PEAK 0xde
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#define LTC3815_MFR_TEMP_PEAK 0xdf
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#define LTC3815_MFR_IIN_PEAK 0xe1
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#define LTC3815_MFR_SPECIAL_ID 0xe7
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#define LTC3815_ID 0x8000
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#define LTC3815_ID_MASK 0xff00
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static int ltc3815_read_byte_data(struct i2c_client *client, int page, int reg)
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{
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int ret;
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switch (reg) {
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case PMBUS_VOUT_MODE:
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/*
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* The chip returns 0x3e, suggesting VID mode with manufacturer
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* specific VID codes. Since the output voltage is reported
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* with a LSB of 0.5mV, override and report direct mode with
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* appropriate coefficients.
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*/
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ret = 0x40;
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break;
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default:
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ret = -ENODATA;
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break;
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}
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return ret;
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}
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static int ltc3815_write_byte(struct i2c_client *client, int page, u8 reg)
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{
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int ret;
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switch (reg) {
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case PMBUS_CLEAR_FAULTS:
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/*
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* LTC3815 does not support the CLEAR_FAULTS command.
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* Emulate it by clearing the status register.
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*/
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ret = pmbus_read_word_data(client, 0, PMBUS_STATUS_WORD);
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if (ret > 0) {
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pmbus_write_word_data(client, 0, PMBUS_STATUS_WORD,
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ret);
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ret = 0;
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}
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break;
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default:
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ret = -ENODATA;
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break;
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}
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return ret;
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}
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static int ltc3815_read_word_data(struct i2c_client *client, int page, int reg)
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{
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int ret;
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switch (reg) {
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case PMBUS_VIRT_READ_VIN_MAX:
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ret = pmbus_read_word_data(client, page, LTC3815_MFR_VIN_PEAK);
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break;
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case PMBUS_VIRT_READ_VOUT_MAX:
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ret = pmbus_read_word_data(client, page, LTC3815_MFR_VOUT_PEAK);
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break;
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case PMBUS_VIRT_READ_TEMP_MAX:
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ret = pmbus_read_word_data(client, page, LTC3815_MFR_TEMP_PEAK);
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break;
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case PMBUS_VIRT_READ_IOUT_MAX:
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ret = pmbus_read_word_data(client, page, LTC3815_MFR_IOUT_PEAK);
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break;
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case PMBUS_VIRT_READ_IIN_MAX:
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ret = pmbus_read_word_data(client, page, LTC3815_MFR_IIN_PEAK);
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break;
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case PMBUS_VIRT_RESET_VOUT_HISTORY:
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case PMBUS_VIRT_RESET_VIN_HISTORY:
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case PMBUS_VIRT_RESET_TEMP_HISTORY:
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case PMBUS_VIRT_RESET_IOUT_HISTORY:
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case PMBUS_VIRT_RESET_IIN_HISTORY:
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ret = 0;
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break;
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default:
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ret = -ENODATA;
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break;
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}
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return ret;
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}
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static int ltc3815_write_word_data(struct i2c_client *client, int page,
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int reg, u16 word)
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{
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int ret;
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switch (reg) {
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case PMBUS_VIRT_RESET_IIN_HISTORY:
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ret = pmbus_write_word_data(client, page,
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LTC3815_MFR_IIN_PEAK, 0);
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break;
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case PMBUS_VIRT_RESET_IOUT_HISTORY:
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ret = pmbus_write_word_data(client, page,
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LTC3815_MFR_IOUT_PEAK, 0);
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break;
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case PMBUS_VIRT_RESET_VOUT_HISTORY:
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ret = pmbus_write_word_data(client, page,
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LTC3815_MFR_VOUT_PEAK, 0);
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break;
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case PMBUS_VIRT_RESET_VIN_HISTORY:
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ret = pmbus_write_word_data(client, page,
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LTC3815_MFR_VIN_PEAK, 0);
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break;
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case PMBUS_VIRT_RESET_TEMP_HISTORY:
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ret = pmbus_write_word_data(client, page,
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LTC3815_MFR_TEMP_PEAK, 0);
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break;
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default:
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ret = -ENODATA;
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break;
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}
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return ret;
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}
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static const struct i2c_device_id ltc3815_id[] = {
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{"ltc3815", 0},
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, ltc3815_id);
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static struct pmbus_driver_info ltc3815_info = {
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.pages = 1,
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.format[PSC_VOLTAGE_IN] = direct,
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.format[PSC_VOLTAGE_OUT] = direct,
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.format[PSC_CURRENT_IN] = direct,
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.format[PSC_CURRENT_OUT] = direct,
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.format[PSC_TEMPERATURE] = direct,
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.m[PSC_VOLTAGE_IN] = 250,
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.b[PSC_VOLTAGE_IN] = 0,
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.R[PSC_VOLTAGE_IN] = 0,
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.m[PSC_VOLTAGE_OUT] = 2,
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.b[PSC_VOLTAGE_OUT] = 0,
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.R[PSC_VOLTAGE_OUT] = 3,
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.m[PSC_CURRENT_IN] = 1,
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.b[PSC_CURRENT_IN] = 0,
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.R[PSC_CURRENT_IN] = 2,
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.m[PSC_CURRENT_OUT] = 1,
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.b[PSC_CURRENT_OUT] = 0,
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.R[PSC_CURRENT_OUT] = 2,
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.m[PSC_TEMPERATURE] = 1,
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.b[PSC_TEMPERATURE] = 0,
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.R[PSC_TEMPERATURE] = 0,
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.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_VOUT |
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PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP,
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.read_byte_data = ltc3815_read_byte_data,
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.read_word_data = ltc3815_read_word_data,
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.write_byte = ltc3815_write_byte,
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.write_word_data = ltc3815_write_word_data,
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};
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static int ltc3815_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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int chip_id;
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if (!i2c_check_functionality(client->adapter,
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I2C_FUNC_SMBUS_READ_WORD_DATA))
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return -ENODEV;
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chip_id = i2c_smbus_read_word_data(client, LTC3815_MFR_SPECIAL_ID);
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if (chip_id < 0)
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return chip_id;
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if ((chip_id & LTC3815_ID_MASK) != LTC3815_ID)
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return -ENODEV;
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return pmbus_do_probe(client, id, <c3815_info);
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}
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static struct i2c_driver ltc3815_driver = {
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.driver = {
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.name = "ltc3815",
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},
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.probe = ltc3815_probe,
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.remove = pmbus_do_remove,
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.id_table = ltc3815_id,
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};
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module_i2c_driver(ltc3815_driver);
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MODULE_AUTHOR("Guenter Roeck");
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MODULE_DESCRIPTION("PMBus driver for LTC3815");
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MODULE_LICENSE("GPL");
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