diff options
Diffstat (limited to 'drivers/hwmon/pmbus/ltc3815.c')
| -rw-r--r-- | drivers/hwmon/pmbus/ltc3815.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus/ltc3815.c b/drivers/hwmon/pmbus/ltc3815.c new file mode 100644 index 000000000000..bb32e6276622 --- /dev/null +++ b/drivers/hwmon/pmbus/ltc3815.c @@ -0,0 +1,215 @@ +/* + * Hardware monitoring driver for LTC3815 + * + * Copyright (c) 2015 Linear Technology + * Copyright (c) 2015 Guenter Roeck + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/jiffies.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include "pmbus.h" + +#define LTC3815_MFR_IOUT_PEAK 0xd7 +#define LTC3815_MFR_VOUT_PEAK 0xdd +#define LTC3815_MFR_VIN_PEAK 0xde +#define LTC3815_MFR_TEMP_PEAK 0xdf +#define LTC3815_MFR_IIN_PEAK 0xe1 +#define LTC3815_MFR_SPECIAL_ID 0xe7 + +#define LTC3815_ID 0x8000 +#define LTC3815_ID_MASK 0xff00 + +static int ltc3815_read_byte_data(struct i2c_client *client, int page, int reg) +{ + int ret; + + switch (reg) { + case PMBUS_VOUT_MODE: + /* + * The chip returns 0x3e, suggesting VID mode with manufacturer + * specific VID codes. Since the output voltage is reported + * with a LSB of 0.5mV, override and report direct mode with + * appropriate coefficients. + */ + ret = 0x40; + break; + default: + ret = -ENODATA; + break; + } + return ret; +} + +static int ltc3815_write_byte(struct i2c_client *client, int page, u8 reg) +{ + int ret; + + switch (reg) { + case PMBUS_CLEAR_FAULTS: + /* + * LTC3815 does not support the CLEAR_FAULTS command. + * Emulate it by clearing the status register. + */ + ret = pmbus_read_word_data(client, 0, PMBUS_STATUS_WORD); + if (ret > 0) { + pmbus_write_word_data(client, 0, PMBUS_STATUS_WORD, + ret); + ret = 0; + } + break; + default: + ret = -ENODATA; + break; + } + return ret; +} + +static int ltc3815_read_word_data(struct i2c_client *client, int page, int reg) +{ + int ret; + + switch (reg) { + case PMBUS_VIRT_READ_VIN_MAX: + ret = pmbus_read_word_data(client, page, LTC3815_MFR_VIN_PEAK); + break; + case PMBUS_VIRT_READ_VOUT_MAX: + ret = pmbus_read_word_data(client, page, LTC3815_MFR_VOUT_PEAK); + break; + case PMBUS_VIRT_READ_TEMP_MAX: + ret = pmbus_read_word_data(client, page, LTC3815_MFR_TEMP_PEAK); + break; + case PMBUS_VIRT_READ_IOUT_MAX: + ret = pmbus_read_word_data(client, page, LTC3815_MFR_IOUT_PEAK); + break; + case PMBUS_VIRT_READ_IIN_MAX: + ret = pmbus_read_word_data(client, page, LTC3815_MFR_IIN_PEAK); + break; + case PMBUS_VIRT_RESET_VOUT_HISTORY: + case PMBUS_VIRT_RESET_VIN_HISTORY: + case PMBUS_VIRT_RESET_TEMP_HISTORY: + case PMBUS_VIRT_RESET_IOUT_HISTORY: + case PMBUS_VIRT_RESET_IIN_HISTORY: + ret = 0; + break; + default: + ret = -ENODATA; + break; + } + return ret; +} + +static int ltc3815_write_word_data(struct i2c_client *client, int page, + int reg, u16 word) +{ + int ret; + + switch (reg) { + case PMBUS_VIRT_RESET_IIN_HISTORY: + ret = pmbus_write_word_data(client, page, + LTC3815_MFR_IIN_PEAK, 0); + break; + case PMBUS_VIRT_RESET_IOUT_HISTORY: + ret = pmbus_write_word_data(client, page, + LTC3815_MFR_IOUT_PEAK, 0); + break; + case PMBUS_VIRT_RESET_VOUT_HISTORY: + ret = pmbus_write_word_data(client, page, + LTC3815_MFR_VOUT_PEAK, 0); + break; + case PMBUS_VIRT_RESET_VIN_HISTORY: + ret = pmbus_write_word_data(client, page, + LTC3815_MFR_VIN_PEAK, 0); + break; + case PMBUS_VIRT_RESET_TEMP_HISTORY: + ret = pmbus_write_word_data(client, page, + LTC3815_MFR_TEMP_PEAK, 0); + break; + default: + ret = -ENODATA; + break; + } + return ret; +} + +static const struct i2c_device_id ltc3815_id[] = { + {"ltc3815", 0}, + { } +}; +MODULE_DEVICE_TABLE(i2c, ltc3815_id); + +static struct pmbus_driver_info ltc3815_info = { + .pages = 1, + .format[PSC_VOLTAGE_IN] = direct, + .format[PSC_VOLTAGE_OUT] = direct, + .format[PSC_CURRENT_IN] = direct, + .format[PSC_CURRENT_OUT] = direct, + .format[PSC_TEMPERATURE] = direct, + .m[PSC_VOLTAGE_IN] = 250, + .b[PSC_VOLTAGE_IN] = 0, + .R[PSC_VOLTAGE_IN] = 0, + .m[PSC_VOLTAGE_OUT] = 2, + .b[PSC_VOLTAGE_OUT] = 0, + .R[PSC_VOLTAGE_OUT] = 3, + .m[PSC_CURRENT_IN] = 1, + .b[PSC_CURRENT_IN] = 0, + .R[PSC_CURRENT_IN] = 2, + .m[PSC_CURRENT_OUT] = 1, + .b[PSC_CURRENT_OUT] = 0, + .R[PSC_CURRENT_OUT] = 2, + .m[PSC_TEMPERATURE] = 1, + .b[PSC_TEMPERATURE] = 0, + .R[PSC_TEMPERATURE] = 0, + .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_VOUT | + PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP, + .read_byte_data = ltc3815_read_byte_data, + .read_word_data = ltc3815_read_word_data, + .write_byte = ltc3815_write_byte, + .write_word_data = ltc3815_write_word_data, +}; + +static int ltc3815_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + int chip_id; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_READ_WORD_DATA)) + return -ENODEV; + + chip_id = i2c_smbus_read_word_data(client, LTC3815_MFR_SPECIAL_ID); + if (chip_id < 0) + return chip_id; + if ((chip_id & LTC3815_ID_MASK) != LTC3815_ID) + return -ENODEV; + + return pmbus_do_probe(client, id, <c3815_info); +} + +static struct i2c_driver ltc3815_driver = { + .driver = { + .name = "ltc3815", + }, + .probe = ltc3815_probe, + .remove = pmbus_do_remove, + .id_table = ltc3815_id, +}; + +module_i2c_driver(ltc3815_driver); + +MODULE_AUTHOR("Guenter Roeck"); +MODULE_DESCRIPTION("PMBus driver for LTC3815"); +MODULE_LICENSE("GPL"); |