forked from Minki/linux
f366fccd08
We read the chip ID from the chip, use it to determine if the chip ID provided to the driver is correct, and report it if wrong. We should also use the correct chip ID to select supported functionality. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Cc: stable@vger.kernel.org # 3.2+ Acked-by: Jean Delvare <khali@linux-fr.org>
381 lines
10 KiB
C
381 lines
10 KiB
C
/*
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* Hardware monitoring driver for LTC2978 and LTC3880
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*
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* Copyright (c) 2011 Ericsson AB.
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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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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/i2c.h>
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#include "pmbus.h"
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enum chips { ltc2978, ltc3880 };
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/* LTC2978 and LTC3880 */
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#define LTC2978_MFR_VOUT_PEAK 0xdd
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#define LTC2978_MFR_VIN_PEAK 0xde
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#define LTC2978_MFR_TEMPERATURE_PEAK 0xdf
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#define LTC2978_MFR_SPECIAL_ID 0xe7
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/* LTC2978 only */
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#define LTC2978_MFR_VOUT_MIN 0xfb
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#define LTC2978_MFR_VIN_MIN 0xfc
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#define LTC2978_MFR_TEMPERATURE_MIN 0xfd
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/* LTC3880 only */
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#define LTC3880_MFR_IOUT_PEAK 0xd7
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#define LTC3880_MFR_CLEAR_PEAKS 0xe3
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#define LTC3880_MFR_TEMPERATURE2_PEAK 0xf4
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#define LTC2978_ID_REV1 0x0121
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#define LTC2978_ID_REV2 0x0122
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#define LTC3880_ID 0x4000
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#define LTC3880_ID_MASK 0xff00
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/*
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* LTC2978 clears peak data whenever the CLEAR_FAULTS command is executed, which
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* happens pretty much each time chip data is updated. Raw peak data therefore
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* does not provide much value. To be able to provide useful peak data, keep an
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* internal cache of measured peak data, which is only cleared if an explicit
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* "clear peak" command is executed for the sensor in question.
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*/
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struct ltc2978_data {
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enum chips id;
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int vin_min, vin_max;
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int temp_min, temp_max;
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int vout_min[8], vout_max[8];
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int iout_max[2];
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int temp2_max;
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struct pmbus_driver_info info;
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};
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#define to_ltc2978_data(x) container_of(x, struct ltc2978_data, info)
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static inline int lin11_to_val(int data)
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{
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s16 e = ((s16)data) >> 11;
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s32 m = (((s16)(data << 5)) >> 5);
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/*
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* mantissa is 10 bit + sign, exponent adds up to 15 bit.
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* Add 6 bit to exponent for maximum accuracy (10 + 15 + 6 = 31).
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*/
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e += 6;
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return (e < 0 ? m >> -e : m << e);
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}
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static int ltc2978_read_word_data_common(struct i2c_client *client, int page,
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int reg)
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{
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const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
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struct ltc2978_data *data = to_ltc2978_data(info);
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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, LTC2978_MFR_VIN_PEAK);
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if (ret >= 0) {
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if (lin11_to_val(ret) > lin11_to_val(data->vin_max))
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data->vin_max = ret;
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ret = data->vin_max;
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}
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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, LTC2978_MFR_VOUT_PEAK);
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if (ret >= 0) {
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/*
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* VOUT is 16 bit unsigned with fixed exponent,
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* so we can compare it directly
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*/
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if (ret > data->vout_max[page])
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data->vout_max[page] = ret;
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ret = data->vout_max[page];
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}
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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,
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LTC2978_MFR_TEMPERATURE_PEAK);
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if (ret >= 0) {
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if (lin11_to_val(ret) > lin11_to_val(data->temp_max))
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data->temp_max = ret;
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ret = data->temp_max;
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}
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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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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 ltc2978_read_word_data(struct i2c_client *client, int page, int reg)
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{
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const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
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struct ltc2978_data *data = to_ltc2978_data(info);
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int ret;
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switch (reg) {
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case PMBUS_VIRT_READ_VIN_MIN:
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ret = pmbus_read_word_data(client, page, LTC2978_MFR_VIN_MIN);
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if (ret >= 0) {
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if (lin11_to_val(ret) < lin11_to_val(data->vin_min))
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data->vin_min = ret;
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ret = data->vin_min;
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}
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break;
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case PMBUS_VIRT_READ_VOUT_MIN:
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ret = pmbus_read_word_data(client, page, LTC2978_MFR_VOUT_MIN);
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if (ret >= 0) {
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/*
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* VOUT_MIN is known to not be supported on some lots
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* of LTC2978 revision 1, and will return the maximum
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* possible voltage if read. If VOUT_MAX is valid and
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* lower than the reading of VOUT_MIN, use it instead.
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*/
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if (data->vout_max[page] && ret > data->vout_max[page])
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ret = data->vout_max[page];
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if (ret < data->vout_min[page])
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data->vout_min[page] = ret;
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ret = data->vout_min[page];
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}
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break;
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case PMBUS_VIRT_READ_TEMP_MIN:
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ret = pmbus_read_word_data(client, page,
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LTC2978_MFR_TEMPERATURE_MIN);
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if (ret >= 0) {
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if (lin11_to_val(ret)
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< lin11_to_val(data->temp_min))
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data->temp_min = ret;
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ret = data->temp_min;
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}
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break;
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case PMBUS_VIRT_READ_IOUT_MAX:
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case PMBUS_VIRT_RESET_IOUT_HISTORY:
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case PMBUS_VIRT_READ_TEMP2_MAX:
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case PMBUS_VIRT_RESET_TEMP2_HISTORY:
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ret = -ENXIO;
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break;
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default:
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ret = ltc2978_read_word_data_common(client, page, reg);
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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 ltc3880_read_word_data(struct i2c_client *client, int page, int reg)
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{
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const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
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struct ltc2978_data *data = to_ltc2978_data(info);
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int ret;
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switch (reg) {
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case PMBUS_VIRT_READ_IOUT_MAX:
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ret = pmbus_read_word_data(client, page, LTC3880_MFR_IOUT_PEAK);
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if (ret >= 0) {
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if (lin11_to_val(ret)
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> lin11_to_val(data->iout_max[page]))
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data->iout_max[page] = ret;
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ret = data->iout_max[page];
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}
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break;
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case PMBUS_VIRT_READ_TEMP2_MAX:
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ret = pmbus_read_word_data(client, page,
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LTC3880_MFR_TEMPERATURE2_PEAK);
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if (ret >= 0) {
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if (lin11_to_val(ret) > lin11_to_val(data->temp2_max))
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data->temp2_max = ret;
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ret = data->temp2_max;
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}
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break;
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case PMBUS_VIRT_READ_VIN_MIN:
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case PMBUS_VIRT_READ_VOUT_MIN:
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case PMBUS_VIRT_READ_TEMP_MIN:
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ret = -ENXIO;
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break;
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case PMBUS_VIRT_RESET_IOUT_HISTORY:
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case PMBUS_VIRT_RESET_TEMP2_HISTORY:
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ret = 0;
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break;
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default:
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ret = ltc2978_read_word_data_common(client, page, reg);
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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 ltc2978_clear_peaks(struct i2c_client *client, int page,
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enum chips id)
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{
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int ret;
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if (id == ltc2978)
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ret = pmbus_write_byte(client, page, PMBUS_CLEAR_FAULTS);
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else
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ret = pmbus_write_byte(client, 0, LTC3880_MFR_CLEAR_PEAKS);
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return ret;
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}
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static int ltc2978_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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const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
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struct ltc2978_data *data = to_ltc2978_data(info);
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int ret;
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switch (reg) {
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case PMBUS_VIRT_RESET_IOUT_HISTORY:
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data->iout_max[page] = 0x7c00;
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ret = ltc2978_clear_peaks(client, page, data->id);
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break;
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case PMBUS_VIRT_RESET_TEMP2_HISTORY:
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data->temp2_max = 0x7c00;
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ret = ltc2978_clear_peaks(client, page, data->id);
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break;
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case PMBUS_VIRT_RESET_VOUT_HISTORY:
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data->vout_min[page] = 0xffff;
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data->vout_max[page] = 0;
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ret = ltc2978_clear_peaks(client, page, data->id);
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break;
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case PMBUS_VIRT_RESET_VIN_HISTORY:
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data->vin_min = 0x7bff;
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data->vin_max = 0x7c00;
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ret = ltc2978_clear_peaks(client, page, data->id);
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break;
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case PMBUS_VIRT_RESET_TEMP_HISTORY:
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data->temp_min = 0x7bff;
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data->temp_max = 0x7c00;
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ret = ltc2978_clear_peaks(client, page, data->id);
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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 ltc2978_id[] = {
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{"ltc2978", ltc2978},
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{"ltc3880", ltc3880},
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{}
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};
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MODULE_DEVICE_TABLE(i2c, ltc2978_id);
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static int ltc2978_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, i;
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struct ltc2978_data *data;
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struct pmbus_driver_info *info;
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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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data = devm_kzalloc(&client->dev, sizeof(struct ltc2978_data),
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GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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chip_id = i2c_smbus_read_word_data(client, LTC2978_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 == LTC2978_ID_REV1 || chip_id == LTC2978_ID_REV2) {
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data->id = ltc2978;
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} else if ((chip_id & LTC3880_ID_MASK) == LTC3880_ID) {
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data->id = ltc3880;
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} else {
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dev_err(&client->dev, "Unsupported chip ID 0x%x\n", chip_id);
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return -ENODEV;
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}
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if (data->id != id->driver_data)
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dev_warn(&client->dev,
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"Device mismatch: Configured %s, detected %s\n",
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id->name,
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ltc2978_id[data->id].name);
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info = &data->info;
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info->write_word_data = ltc2978_write_word_data;
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data->vin_min = 0x7bff;
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data->vin_max = 0x7c00;
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data->temp_min = 0x7bff;
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data->temp_max = 0x7c00;
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data->temp2_max = 0x7c00;
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switch (data->id) {
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case ltc2978:
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info->read_word_data = ltc2978_read_word_data;
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info->pages = 8;
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info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
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| PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
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| PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
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for (i = 1; i < 8; i++) {
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info->func[i] = PMBUS_HAVE_VOUT
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| PMBUS_HAVE_STATUS_VOUT;
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}
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break;
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case ltc3880:
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info->read_word_data = ltc3880_read_word_data;
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info->pages = 2;
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info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
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| PMBUS_HAVE_STATUS_INPUT
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| PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
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| PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
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| PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
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| PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
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info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
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| PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
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| PMBUS_HAVE_POUT
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| PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
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data->iout_max[0] = 0x7c00;
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data->iout_max[1] = 0x7c00;
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break;
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default:
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return -ENODEV;
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}
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for (i = 0; i < info->pages; i++)
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data->vout_min[i] = 0xffff;
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return pmbus_do_probe(client, id, info);
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}
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/* This is the driver that will be inserted */
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static struct i2c_driver ltc2978_driver = {
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.driver = {
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.name = "ltc2978",
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},
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.probe = ltc2978_probe,
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.remove = pmbus_do_remove,
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.id_table = ltc2978_id,
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};
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module_i2c_driver(ltc2978_driver);
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MODULE_AUTHOR("Guenter Roeck");
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MODULE_DESCRIPTION("PMBus driver for LTC2978 and LTC3880");
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MODULE_LICENSE("GPL");
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