/* * Hardware monitoring driver for LTC2978 and LTC3880 * * Copyright (c) 2011 Ericsson AB. * * 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. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/err.h> #include <linux/slab.h> #include <linux/i2c.h> #include "pmbus.h" enum chips { ltc2978, ltc3880 }; /* LTC2978 and LTC3880 */ #define LTC2978_MFR_VOUT_PEAK 0xdd #define LTC2978_MFR_VIN_PEAK 0xde #define LTC2978_MFR_TEMPERATURE_PEAK 0xdf #define LTC2978_MFR_SPECIAL_ID 0xe7 /* LTC2978 only */ #define LTC2978_MFR_VOUT_MIN 0xfb #define LTC2978_MFR_VIN_MIN 0xfc #define LTC2978_MFR_TEMPERATURE_MIN 0xfd /* LTC3880 only */ #define LTC3880_MFR_IOUT_PEAK 0xd7 #define LTC3880_MFR_CLEAR_PEAKS 0xe3 #define LTC3880_MFR_TEMPERATURE2_PEAK 0xf4 #define LTC2978_ID_REV1 0x0121 #define LTC2978_ID_REV2 0x0122 #define LTC3880_ID 0x4000 #define LTC3880_ID_MASK 0xff00 /* * LTC2978 clears peak data whenever the CLEAR_FAULTS command is executed, which * happens pretty much each time chip data is updated. Raw peak data therefore * does not provide much value. To be able to provide useful peak data, keep an * internal cache of measured peak data, which is only cleared if an explicit * "clear peak" command is executed for the sensor in question. */ struct ltc2978_data { enum chips id; int vin_min, vin_max; int temp_min, temp_max; int vout_min[8], vout_max[8]; int iout_max[2]; int temp2_max[2]; struct pmbus_driver_info info; }; #define to_ltc2978_data(x) container_of(x, struct ltc2978_data, info) static inline int lin11_to_val(int data) { s16 e = ((s16)data) >> 11; s32 m = (((s16)(data << 5)) >> 5); /* * mantissa is 10 bit + sign, exponent adds up to 15 bit. * Add 6 bit to exponent for maximum accuracy (10 + 15 + 6 = 31). */ e += 6; return (e < 0 ? m >> -e : m << e); } static int ltc2978_read_word_data_common(struct i2c_client *client, int page, int reg) { const struct pmbus_driver_info *info = pmbus_get_driver_info(client); struct ltc2978_data *data = to_ltc2978_data(info); int ret; switch (reg) { case PMBUS_VIRT_READ_VIN_MAX: ret = pmbus_read_word_data(client, page, LTC2978_MFR_VIN_PEAK); if (ret >= 0) { if (lin11_to_val(ret) > lin11_to_val(data->vin_max)) data->vin_max = ret; ret = data->vin_max; } break; case PMBUS_VIRT_READ_VOUT_MAX: ret = pmbus_read_word_data(client, page, LTC2978_MFR_VOUT_PEAK); if (ret >= 0) { /* * VOUT is 16 bit unsigned with fixed exponent, * so we can compare it directly */ if (ret > data->vout_max[page]) data->vout_max[page] = ret; ret = data->vout_max[page]; } break; case PMBUS_VIRT_READ_TEMP_MAX: ret = pmbus_read_word_data(client, page, LTC2978_MFR_TEMPERATURE_PEAK); if (ret >= 0) { if (lin11_to_val(ret) > lin11_to_val(data->temp_max)) data->temp_max = ret; ret = data->temp_max; } break; case PMBUS_VIRT_RESET_VOUT_HISTORY: case PMBUS_VIRT_RESET_VIN_HISTORY: case PMBUS_VIRT_RESET_TEMP_HISTORY: ret = 0; break; default: ret = -ENODATA; break; } return ret; } static int ltc2978_read_word_data(struct i2c_client *client, int page, int reg) { const struct pmbus_driver_info *info = pmbus_get_driver_info(client); struct ltc2978_data *data = to_ltc2978_data(info); int ret; switch (reg) { case PMBUS_VIRT_READ_VIN_MIN: ret = pmbus_read_word_data(client, page, LTC2978_MFR_VIN_MIN); if (ret >= 0) { if (lin11_to_val(ret) < lin11_to_val(data->vin_min)) data->vin_min = ret; ret = data->vin_min; } break; case PMBUS_VIRT_READ_VOUT_MIN: ret = pmbus_read_word_data(client, page, LTC2978_MFR_VOUT_MIN); if (ret >= 0) { /* * VOUT_MIN is known to not be supported on some lots * of LTC2978 revision 1, and will return the maximum * possible voltage if read. If VOUT_MAX is valid and * lower than the reading of VOUT_MIN, use it instead. */ if (data->vout_max[page] && ret > data->vout_max[page]) ret = data->vout_max[page]; if (ret < data->vout_min[page]) data->vout_min[page] = ret; ret = data->vout_min[page]; } break; case PMBUS_VIRT_READ_TEMP_MIN: ret = pmbus_read_word_data(client, page, LTC2978_MFR_TEMPERATURE_MIN); if (ret >= 0) { if (lin11_to_val(ret) < lin11_to_val(data->temp_min)) data->temp_min = ret; ret = data->temp_min; } break; case PMBUS_VIRT_READ_IOUT_MAX: case PMBUS_VIRT_RESET_IOUT_HISTORY: case PMBUS_VIRT_READ_TEMP2_MAX: case PMBUS_VIRT_RESET_TEMP2_HISTORY: ret = -ENXIO; break; default: ret = ltc2978_read_word_data_common(client, page, reg); break; } return ret; } static int ltc3880_read_word_data(struct i2c_client *client, int page, int reg) { const struct pmbus_driver_info *info = pmbus_get_driver_info(client); struct ltc2978_data *data = to_ltc2978_data(info); int ret; switch (reg) { case PMBUS_VIRT_READ_IOUT_MAX: ret = pmbus_read_word_data(client, page, LTC3880_MFR_IOUT_PEAK); if (ret >= 0) { if (lin11_to_val(ret) > lin11_to_val(data->iout_max[page])) data->iout_max[page] = ret; ret = data->iout_max[page]; } break; case PMBUS_VIRT_READ_TEMP2_MAX: ret = pmbus_read_word_data(client, page, LTC3880_MFR_TEMPERATURE2_PEAK); if (ret >= 0) { if (lin11_to_val(ret) > lin11_to_val(data->temp2_max[page])) data->temp2_max[page] = ret; ret = data->temp2_max[page]; } break; case PMBUS_VIRT_READ_VIN_MIN: case PMBUS_VIRT_READ_VOUT_MIN: case PMBUS_VIRT_READ_TEMP_MIN: ret = -ENXIO; break; case PMBUS_VIRT_RESET_IOUT_HISTORY: case PMBUS_VIRT_RESET_TEMP2_HISTORY: ret = 0; break; default: ret = ltc2978_read_word_data_common(client, page, reg); break; } return ret; } static int ltc2978_clear_peaks(struct i2c_client *client, int page, enum chips id) { int ret; if (id == ltc2978) ret = pmbus_write_byte(client, page, PMBUS_CLEAR_FAULTS); else ret = pmbus_write_byte(client, 0, LTC3880_MFR_CLEAR_PEAKS); return ret; } static int ltc2978_write_word_data(struct i2c_client *client, int page, int reg, u16 word) { const struct pmbus_driver_info *info = pmbus_get_driver_info(client); struct ltc2978_data *data = to_ltc2978_data(info); int ret; switch (reg) { case PMBUS_VIRT_RESET_IOUT_HISTORY: data->iout_max[page] = 0x7fff; ret = ltc2978_clear_peaks(client, page, data->id); break; case PMBUS_VIRT_RESET_TEMP2_HISTORY: data->temp2_max[page] = 0x7fff; ret = ltc2978_clear_peaks(client, page, data->id); break; case PMBUS_VIRT_RESET_VOUT_HISTORY: data->vout_min[page] = 0xffff; data->vout_max[page] = 0; ret = ltc2978_clear_peaks(client, page, data->id); break; case PMBUS_VIRT_RESET_VIN_HISTORY: data->vin_min = 0x7bff; data->vin_max = 0; ret = ltc2978_clear_peaks(client, page, data->id); break; case PMBUS_VIRT_RESET_TEMP_HISTORY: data->temp_min = 0x7bff; data->temp_max = 0x7fff; ret = ltc2978_clear_peaks(client, page, data->id); break; default: ret = -ENODATA; break; } return ret; } static const struct i2c_device_id ltc2978_id[] = { {"ltc2978", ltc2978}, {"ltc3880", ltc3880}, {} }; MODULE_DEVICE_TABLE(i2c, ltc2978_id); static int ltc2978_probe(struct i2c_client *client, const struct i2c_device_id *id) { int chip_id, i; struct ltc2978_data *data; struct pmbus_driver_info *info; if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)) return -ENODEV; data = devm_kzalloc(&client->dev, sizeof(struct ltc2978_data), GFP_KERNEL); if (!data) return -ENOMEM; chip_id = i2c_smbus_read_word_data(client, LTC2978_MFR_SPECIAL_ID); if (chip_id < 0) return chip_id; if (chip_id == LTC2978_ID_REV1 || chip_id == LTC2978_ID_REV2) { data->id = ltc2978; } else if ((chip_id & LTC3880_ID_MASK) == LTC3880_ID) { data->id = ltc3880; } else { dev_err(&client->dev, "Unsupported chip ID 0x%x\n", chip_id); return -ENODEV; } if (data->id != id->driver_data) dev_warn(&client->dev, "Device mismatch: Configured %s, detected %s\n", id->name, ltc2978_id[data->id].name); info = &data->info; info->write_word_data = ltc2978_write_word_data; data->vout_min[0] = 0xffff; data->vin_min = 0x7bff; data->temp_min = 0x7bff; data->temp_max = 0x7fff; switch (id->driver_data) { case ltc2978: info->read_word_data = ltc2978_read_word_data; info->pages = 8; info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP; for (i = 1; i < 8; i++) { info->func[i] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT; data->vout_min[i] = 0xffff; } break; case ltc3880: info->read_word_data = ltc3880_read_word_data; info->pages = 2; info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP; info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP; data->vout_min[1] = 0xffff; break; default: return -ENODEV; } return pmbus_do_probe(client, id, info); } /* This is the driver that will be inserted */ static struct i2c_driver ltc2978_driver = { .driver = { .name = "ltc2978", }, .probe = ltc2978_probe, .remove = pmbus_do_remove, .id_table = ltc2978_id, }; module_i2c_driver(ltc2978_driver); MODULE_AUTHOR("Guenter Roeck"); MODULE_DESCRIPTION("PMBus driver for LTC2978 and LTC3880"); MODULE_LICENSE("GPL");