diff options
| -rw-r--r-- | Documentation/hwmon/max31827.rst | 13 | ||||
| -rw-r--r-- | drivers/hwmon/max31827.c | 18 |
2 files changed, 22 insertions, 9 deletions
diff --git a/Documentation/hwmon/max31827.rst b/Documentation/hwmon/max31827.rst index 44ab9dc064cb..9c11a9518c67 100644 --- a/Documentation/hwmon/max31827.rst +++ b/Documentation/hwmon/max31827.rst @@ -131,7 +131,14 @@ The Fault Queue bits select how many consecutive temperature faults must occur before overtemperature or undertemperature faults are indicated in the corresponding status bits. -Notes ------ +PEC Support +----------- + +When reading a register value, the PEC byte is computed and sent by the chip. + +PEC on word data transaction respresents a signifcant increase in bandwitdh +usage (+33% for both write and reads) in normal conditions. -PEC is not implemented. +Since this operation implies there will be an extra delay to each +transaction, PEC can be disabled or enabled through sysfs. +Just write 1 to the "pec" file for enabling PEC and 0 for disabling it. diff --git a/drivers/hwmon/max31827.c b/drivers/hwmon/max31827.c index f8a13b30f100..4d89b6a7060b 100644 --- a/drivers/hwmon/max31827.c +++ b/drivers/hwmon/max31827.c @@ -24,6 +24,7 @@ #define MAX31827_CONFIGURATION_1SHOT_MASK BIT(0) #define MAX31827_CONFIGURATION_CNV_RATE_MASK GENMASK(3, 1) +#define MAX31827_CONFIGURATION_PEC_EN_MASK BIT(4) #define MAX31827_CONFIGURATION_TIMEOUT_MASK BIT(5) #define MAX31827_CONFIGURATION_RESOLUTION_MASK GENMASK(7, 6) #define MAX31827_CONFIGURATION_ALRM_POL_MASK BIT(8) @@ -382,7 +383,8 @@ static int max31827_write(struct device *dev, enum hwmon_sensor_types type, } case hwmon_chip: - if (attr == hwmon_chip_update_interval) { + switch (attr) { + case hwmon_chip_update_interval: if (!st->enable) return -EINVAL; @@ -410,14 +412,18 @@ static int max31827_write(struct device *dev, enum hwmon_sensor_types type, return ret; st->update_interval = val; - } - break; + return 0; + case hwmon_chip_pec: + return regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG, + MAX31827_CONFIGURATION_PEC_EN_MASK, + val ? MAX31827_CONFIGURATION_PEC_EN_MASK : 0); + default: + return -EOPNOTSUPP; + } default: return -EOPNOTSUPP; } - - return 0; } static ssize_t temp1_resolution_show(struct device *dev, @@ -583,7 +589,7 @@ static const struct hwmon_channel_info *max31827_info[] = { HWMON_T_MIN_HYST | HWMON_T_MIN_ALARM | HWMON_T_MAX | HWMON_T_MAX_HYST | HWMON_T_MAX_ALARM), - HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL), + HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL | HWMON_C_PEC), NULL, }; |