forked from luck/tmp_suning_uos_patched
hwmon: (ltc2978) Add polling for chips requiring it
Some of the LTC chips supported by this driver have to be polled to ensure that they are ready to accept commands. Signed-off-by: Michael Jones <mike@proclivis.com> [Guenter Roeck: simplifications and formatting changes] Signed-off-by: Guenter Roeck <linux@roeck-us.net>
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@ -3,6 +3,7 @@
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*
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* Copyright (c) 2011 Ericsson AB.
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* Copyright (c) 2013, 2014, 2015 Guenter Roeck
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* Copyright (c) 2015 Linear Technology
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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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@ -15,6 +16,8 @@
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* GNU General Public License for more details.
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*/
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#include <linux/delay.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 <linux/init.h>
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@ -32,6 +35,7 @@ enum chips { ltc2974, ltc2975, ltc2977, ltc2978, ltc2980, ltc3880, ltc3882,
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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 /* Undocumented on LTC3882 */
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#define LTC2978_MFR_COMMON 0xef
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/* LTC2974, LTC2975, LCT2977, LTC2980, LTC2978, and LTM2987 */
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#define LTC2978_MFR_VOUT_MIN 0xfb
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@ -82,6 +86,11 @@ enum chips { ltc2974, ltc2975, ltc2977, ltc2978, ltc2980, ltc3880, ltc3882,
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#define LTC3880_NUM_PAGES 2
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#define LTC3883_NUM_PAGES 1
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#define LTC_POLL_TIMEOUT 100 /* in milli-seconds */
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#define LTC_NOT_BUSY BIT(5)
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#define LTC_NOT_PENDING BIT(4)
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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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@ -105,8 +114,81 @@ struct ltc2978_data {
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#define to_ltc2978_data(x) container_of(x, struct ltc2978_data, info)
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#define FEAT_CLEAR_PEAKS BIT(0)
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#define FEAT_NEEDS_POLLING BIT(1)
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#define has_clear_peaks(d) ((d)->features & FEAT_CLEAR_PEAKS)
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#define needs_polling(d) ((d)->features & FEAT_NEEDS_POLLING)
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static int ltc_wait_ready(struct i2c_client *client)
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{
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unsigned long timeout = jiffies + msecs_to_jiffies(LTC_POLL_TIMEOUT);
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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 status;
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u8 mask;
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if (!needs_polling(data))
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return 0;
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/*
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* LTC3883 does not support LTC_NOT_PENDING, even though
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* the datasheet claims that it does.
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*/
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mask = LTC_NOT_BUSY;
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if (data->id != ltc3883)
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mask |= LTC_NOT_PENDING;
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do {
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status = pmbus_read_byte_data(client, 0, LTC2978_MFR_COMMON);
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if (status == -EBADMSG || status == -ENXIO) {
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/* PEC error or NACK: chip may be busy, try again */
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usleep_range(50, 100);
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continue;
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}
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if (status < 0)
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return status;
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if ((status & mask) == mask)
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return 0;
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usleep_range(50, 100);
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} while (time_before(jiffies, timeout));
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return -ETIMEDOUT;
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}
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static int ltc_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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ret = ltc_wait_ready(client);
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if (ret < 0)
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return ret;
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return pmbus_read_word_data(client, page, reg);
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}
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static int ltc_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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ret = ltc_wait_ready(client);
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if (ret < 0)
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return ret;
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return pmbus_read_byte_data(client, page, reg);
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}
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static int ltc_write_byte(struct i2c_client *client, int page, u8 byte)
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{
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int ret;
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ret = ltc_wait_ready(client);
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if (ret < 0)
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return ret;
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return pmbus_write_byte(client, page, byte);
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}
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static inline int lin11_to_val(int data)
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{
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@ -126,7 +208,7 @@ static int ltc_get_max(struct ltc2978_data *data, struct i2c_client *client,
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{
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int ret;
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ret = pmbus_read_word_data(client, page, reg);
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ret = ltc_read_word_data(client, page, reg);
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if (ret >= 0) {
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if (lin11_to_val(ret) > lin11_to_val(*pmax))
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*pmax = ret;
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@ -140,7 +222,7 @@ static int ltc_get_min(struct ltc2978_data *data, struct i2c_client *client,
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{
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int ret;
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ret = pmbus_read_word_data(client, page, reg);
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ret = ltc_read_word_data(client, page, reg);
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if (ret >= 0) {
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if (lin11_to_val(ret) < lin11_to_val(*pmin))
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*pmin = ret;
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@ -162,7 +244,7 @@ static int ltc2978_read_word_data_common(struct i2c_client *client, int page,
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&data->vin_max);
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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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ret = ltc_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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@ -184,6 +266,9 @@ static int ltc2978_read_word_data_common(struct i2c_client *client, int page,
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ret = 0;
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break;
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default:
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ret = ltc_wait_ready(client);
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if (ret < 0)
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return ret;
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ret = -ENODATA;
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break;
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}
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@ -202,7 +287,7 @@ static int ltc2978_read_word_data(struct i2c_client *client, int page, int reg)
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&data->vin_min);
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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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ret = ltc_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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@ -353,9 +438,9 @@ static int ltc2978_clear_peaks(struct ltc2978_data *data,
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int ret;
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if (has_clear_peaks(data))
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ret = pmbus_write_byte(client, 0, LTC3880_MFR_CLEAR_PEAKS);
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ret = ltc_write_byte(client, 0, LTC3880_MFR_CLEAR_PEAKS);
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else
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ret = pmbus_write_byte(client, page, PMBUS_CLEAR_FAULTS);
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ret = ltc_write_byte(client, page, PMBUS_CLEAR_FAULTS);
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return ret;
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}
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@ -403,6 +488,9 @@ static int ltc2978_write_word_data(struct i2c_client *client, int page,
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ret = ltc2978_clear_peaks(data, client, page);
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break;
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default:
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ret = ltc_wait_ready(client);
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if (ret < 0)
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return ret;
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ret = -ENODATA;
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break;
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}
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@ -530,6 +618,9 @@ static int ltc2978_probe(struct i2c_client *client,
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info = &data->info;
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info->write_word_data = ltc2978_write_word_data;
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info->write_byte = ltc_write_byte;
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info->read_word_data = ltc_read_word_data;
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info->read_byte_data = ltc_read_byte_data;
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data->vin_min = 0x7bff;
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data->vin_max = 0x7c00;
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@ -588,7 +679,7 @@ static int ltc2978_probe(struct i2c_client *client,
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case ltc3880:
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case ltc3887:
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case ltm4676:
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data->features |= FEAT_CLEAR_PEAKS;
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data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
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info->read_word_data = ltc3880_read_word_data;
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info->pages = LTC3880_NUM_PAGES;
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info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
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| PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
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break;
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case ltc3882:
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data->features |= FEAT_CLEAR_PEAKS;
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data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
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info->read_word_data = ltc3880_read_word_data;
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info->pages = LTC3880_NUM_PAGES;
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info->func[0] = PMBUS_HAVE_VIN
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| PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
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break;
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case ltc3883:
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data->features |= FEAT_CLEAR_PEAKS;
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data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
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info->read_word_data = ltc3883_read_word_data;
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info->pages = LTC3883_NUM_PAGES;
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info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
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| PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
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break;
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case ltc3886:
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data->features |= FEAT_CLEAR_PEAKS;
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data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
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info->read_word_data = ltc3883_read_word_data;
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info->pages = LTC3880_NUM_PAGES;
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info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
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