1e4b76830SShawn McCarney# rail 2e4b76830SShawn McCarney 3e4b76830SShawn McCarney## Description 4e4b76830SShawn McCarney 5e4b76830SShawn McCarneyA voltage rail that is enabled or monitored by the power sequencer device. 6e4b76830SShawn McCarney 7*9ec0d43dSShawn McCarneyThe "check_status_vout", "compare_voltage_to_limit", and "gpio" properties 8e4b76830SShawn McCarneyspecify how to obtain the pgood status of the rail. You can specify more than 9e4b76830SShawn McCarneyone of these properties if necessary. 10e4b76830SShawn McCarney 11e4b76830SShawn McCarney## Properties 12e4b76830SShawn McCarney 13e4b76830SShawn McCarney| Name | Required | Type | Description | 14*9ec0d43dSShawn McCarney| :----------------------- | :-----------------: | :---------------------- | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | 15e4b76830SShawn McCarney| name | yes | string | Unique name for the rail. Can only contain letters (A-Z, a-z), numbers (0-9), period (.), and underscore (\_). | 16e4b76830SShawn McCarney| presence | no | string | D-Bus inventory path of a system component which must be present in order for the rail to be present. If this property is not specified, the rail is assumed to always be present. | 17e4b76830SShawn McCarney| page | see [notes](#notes) | number | PMBus PAGE number of the rail. | 1816e493afSShawn McCarney| is_power_supply_rail | no | boolean (true or false) | If true, this rail is produced by a power supply. Power supply rails require special error handling. If an error is detected in a power supply device, and the pgood status is false for a power supply rail, the power supply error is logged as the cause of the pgood failure. The default value of this property is false. | 19e4b76830SShawn McCarney| check_status_vout | no | boolean (true or false) | If true, determine the pgood status of the rail by checking the value of the PMBus STATUS_VOUT command. If one of the error bits is set, the rail pgood will be considered false. The default value of this property is false. | 20*9ec0d43dSShawn McCarney| compare_voltage_to_limit | no | boolean (true or false) | If true, determine the pgood status of the rail by comparing the output voltage (READ_VOUT) to the undervoltage fault limit (VOUT_UV_FAULT_LIMIT). If the output voltage is below this limit, the rail pgood will be considered false. The default value of this property is false. | 21e4b76830SShawn McCarney| gpio | no | [gpio](gpio.md) | Determine the pgood status of the rail by reading a GPIO. | 22e4b76830SShawn McCarney 23e4b76830SShawn McCarney### Notes 24e4b76830SShawn McCarney 25e4b76830SShawn McCarney- The "page" property is required if the "check_status_vout" or 26*9ec0d43dSShawn McCarney "compare_voltage_to_limit" property is true. 27e4b76830SShawn McCarney 28e4b76830SShawn McCarney## Examples 29e4b76830SShawn McCarney 30e4b76830SShawn McCarney``` 31e4b76830SShawn McCarney{ 32e4b76830SShawn McCarney "name": "VDD_CPU0", 33e4b76830SShawn McCarney "page": 11, 34e4b76830SShawn McCarney "check_status_vout": true 35e4b76830SShawn McCarney} 36e4b76830SShawn McCarney``` 37e4b76830SShawn McCarney 38e4b76830SShawn McCarney``` 39e4b76830SShawn McCarney{ 40e4b76830SShawn McCarney "name": "VCS_CPU1", 41e4b76830SShawn McCarney "presence": "/xyz/openbmc_project/inventory/system/chassis/motherboard/cpu1", 42e4b76830SShawn McCarney "gpio": { "line": 60 } 43e4b76830SShawn McCarney} 44e4b76830SShawn McCarney``` 45