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gerrit.openbmc.org / openbmc / phosphor-buttons / refs/heads/master
commitea47dd49799e74f082a0a1386efac9bdfd6aaba4[log] [tgz]
authorMatt Spinler <spinler@us.ibm.com>Wed Aug 20 13:07:20 2025 -0500
committerPatrick Williams <patrick@stwcx.xyz>Wed Aug 20 16:38:15 2025 -0400
treef6fac3608a2ccb99dc039d31252ab976bc245063
parent5f3c2e5b1115d0b532c8dc5330009fea42d4f15b [diff]
Don't need indexed button name if only 1 chassis

The commit '31ce375 Support multi power buttons with multi behaviors'
created an assumption that the power button name in gpio_defs.json would
always have a chassis instance number appended to it, and would add an
indexed name as a button factory map key.

That means when ButtonFactor::createInstance() is called with a power
button name without an index, it would not create a PowerButton instance
and button presses wouldn't work.

Instead of changing all of the existing single chassis gpio_defs.json
files in openbmc/openbmc, instead change the factory registration
wrapper code to only register that button as a indexed one if the
provided meson option contains more than 1 chassis.

Tested:
A power button press works to power on the system again.

Fixes: 31ce375e7e71 ("Support multi power buttons with multi behaviors")
Change-Id: I15d02a811aae592adf36c3ac07afd0fc6c15450a
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
1 file changed
tree: f6fac3608a2ccb99dc039d31252ab976bc245063
  1. inc/
  2. service_files/
  3. src/
  4. subprojects/
  5. .clang-format
  6. .gitignore
  7. LICENSE
  8. meson.build
  9. meson.options
  10. meson_config.hpp.in
  11. OWNERS
  12. README.md
README.md

phosphor-buttons

Phosphor-buttons has a collection of IO event handler interfaces for physical inputs which are typically part of some sort of panel.

It defines an individual dbus interface object for each physical button/switch inputs such as power button, reset button etc. Each button interface monitors its associated IO for event changes and emits signals that the button-handler application listens for.

Button Behavior

Power Button

All events occur when the button is released.

If the power is off, power on the host.

If the power is on, it depends on how long the press was and which options are enabled:

  • Short press: Do a host power off
  • Long press, as determined by the 'long-press-time-ms' meson option: Do a chassis (hard) power off.

Custom Power Button Profiles

The 'power-button-profile' meson option can be used to select custom power button profiles that have different behaviors.

Available profiles are:

  • host_then_chassis_poweroff: When power is on, short presses are ignored and a long press issues a host power off first and then a chassis power off if held past a certain time. This class has additional details.

Multi-Host Buttons

See this section below.

Reset Button

When released:

  • If 'reset-button-do-warm-reboot' meson option is set to enabled, does warm reboot the host.
  • Otherwise, reboots the host (default behavior)

ID Button

When released, toggles the 'enclosure_identify' LED group provided by the phosphor-led-manager repository. The group name can be changed using the 'id-led-group' meson option.

Gpio defs config

In order to monitor a button/input interface the respective gpio config details should be mentioned in the gpio defs json file - /etc/default/obmc/gpio/gpio_defs.json

  1. The button interface type name.
  2. An array consists of single or multiple gpio configs associated with the specific button interface.

A gpio can be mapped using the "pin" or "num" keyword. The "pin" key uses alphanumerical references while the "num" key supports the integer pin number.

example gpio def Json config

{
  "gpio_definitions": [
    {
      "name": "POWER_BUTTON",
      "pin": "D0",
      "direction": "both"
    },
    {
      "name": "RESET_BUTTON",
      "pin": "AB0",
      "direction": "both"
    },
    {
      "name": "HOST_SELECTOR",

      "group_gpio_config": [
        {
          "pin": "AA4",
          "direction": "both"
        },
        {
          "pin": "AA5",
          "direction": "both"
        },
        {
          "pin": "AA6",
          "direction": "both"
        },
        {
          "pin": "AA7",
          "direction": "both"
        }
      ]
    }
  ]
}

Single gpio config

This config is original config which can be used for configs with only single gpio such as power button,reset button, OCP debug card host select button.

{
  "name": "POWER_BUTTON",
  "pin": "D0",
  "direction": "both"
}

Note: this config is used by most of the other platforms so this format is kept as it is so that existing gpio configs do not get affected.

Group gpio config

The following configs are related to multi-host bmc systems more info explained in the design: https://github.com/openbmc/docs/blob/master/designs/multihost-phosphor-buttons.md

Host selector gpio config example

The host selector has four gpios associated. So the related gpios are mentioned in a json array named group_gpio_config.

  • name - This is name of the specific gpio line
  • pin - This represents the pin number from linux dts file.
  • polarity - polarity type of the gpio
  • max_position - This represents the max number of hosts in the multi-host bmc system.
  • host_selector_map - This map is oem specific host position map which has how the value read from the host selector gpios is mapped to the respective host number.

Optional: Polling Configuration Some platforms expose the host selector via a CPLD as GPIO inputs without edge-triggered interrupt support (e.g., no edge detection on GPIOs). In such situations, software-based polling mode can be enabled using the following optional fields in the JSON configuration:

  • polling_mode : Set to true to enable polling mode.
  • polling_interval_ms (optional): Polling interval in milliseconds. Defaults to 1000 ms if not specified.

Config Example

A.Interrupt example

Example : The value of "7" derived from the 4 host select gpio lines are mapped to host position 1.

{
  "name": "HOST_SELECTOR",

  "group_gpio_config": [
    {
      "name": "host_select_0",
      "pin": "AA4",
      "direction": "both",
      "polarity": "active_high"
    },
    {
      "name": "host_select_1",
      "pin": "AA5",
      "direction": "both",
      "polarity": "active_high"
    },
    {
      "name": "host_select_2",
      "pin": "AA6",
      "direction": "both",
      "polarity": "active_high"
    },
    {
      "name": "host_select_3",
      "pin": "AA7",
      "direction": "both",
      "polarity": "active_high"
    }
  ],
  "max_position": 4,
  "host_selector_map": {
    "6": 0,
    "7": 1,
    "8": 2,
    "9": 3,
    "10": 4,
    "11": 0,
    "12": 1,
    "13": 2,
    "14": 3,
    "15": 4
  }
}

B.Polling example

{
  "name": "HOST_SELECTOR",
  "polling_mode": true,
  "polling_interval_ms": 3000,
  "group_gpio_config": [
    {
      "name": "host_select_sel_0",
      "num": 2340,
      "direction": "in",
      "polarity": "active_low"
    },
    {
      "name": "host_select_sel_1",
      "num": 2341,
      "direction": "in",
      "polarity": "active_low"
    },
    {
      "name": "host_select_sel_2",
      "num": 2342,
      "direction": "in",
      "polarity": "active_low"
    },
    {
      "name": "host_select_sel_3",
      "num": 2343,
      "direction": "in",
      "polarity": "active_low"
    }
  ],
  "max_position": 8,
  "host_selector_map": {
    "0": 0,
    "1": 1,
    "2": 2,
    "3": 3,
    "4": 4,
    "5": 5,
    "6": 6,
    "7": 7,
    "8": 8
  }
}

Host selector cpld config example

There are also some systems that get the host selector selection from the CPLD, the configuration is provided below.

  • name - The button interface type name.
  • i2c_bus - The i2c bus of cpld
  • i2c_address - The i2c address of cpld
  • register_name - The register file name exported by CLD driver for IO event listen
  • max_position - This represents the max number of hosts in the multi-host bmc system.
{
  "cpld_definitions": [
    {
      "name": "HOST_SELECTOR",
      "i2c_bus": 12,
      "i2c_address": 15,
      "register_name": "uart-selection-debug-card",
      "max_position": 4
    }
  ]
}

Serial uart mux config

Similar to host selector there are multiple gpios associated with the serial uart mux. These gpio configs are specified as part of json array "group_gpio_config".

Here the serial uart mux output is accessed via OCP debug card. SO the OCP debug card present gpio is mentioned part of the group_gpio_config. The debug card present gpio is identified by its name "debug_card_present".

The other gpios part of the group gpio config is serial uart MUX gpio select lines and serial_uart_rx line.

  • name - this is name of the specific gpio line
  • pin - this represents the pin number from linux dts file.
  • polarity - polarity type of the gpio
  • serial_uart_mux_map - This is the map for selected host position to the serial uart mux select output value
{
  "name": "SERIAL_UART_MUX",

  "group_gpio_config": [
    {
      "name": "serial_uart_sel_0",
      "pin": "E0",
      "direction": "out",
      "polarity": "active_high"
    },
    {
      "name": "serial_uart_sel_1",
      "pin": "E1",
      "direction": "out",
      "polarity": "active_high"
    },
    {
      "name": "serial_uart_sel_2",
      "pin": "E2",
      "direction": "out",
      "polarity": "active_high"
    },
    {
      "name": "serial_uart_sel_3",
      "pin": "E3",
      "direction": "out",
      "polarity": "active_high"
    },
    {
      "name": "serial_uart_rx",
      "pin": "E4",
      "direction": "out",
      "polarity": "active_high"
    },
    {
      "name": "debug_card_present",
      "pin": "R3",
      "direction": "both",
      "polarity": "active_high"
    }
  ],
  "serial_uart_mux_map": {
    "0": 4,
    "1": 0,
    "2": 1,
    "3": 2,
    "4": 3
  }
}

Multiple power gpio config example

This config is used for configs with multiple power buttons on each slots and whole sled, or for which needs multi-level chassis power control behavior.

name - this is name of the specific gpio line, "POWER_BUTTON" + the index of chassis instance

  • pin - this represents the pin number from linux dts file.
  • multi-action - default no action, set the corresponding behavior with following format:
  • duration - activate when pulling gpio over this value (unit: millisecond)
  • action - chassis power control behavior
{
  "gpio_definitions": [
    {
      "name": "POWER_BUTTON0",
      "pin": "I6",
      "direction": "both",
      "multi-action": [
        {
          "duration": 4000,
          "action": "chassis cycle"
        }
      ]
    },
    {
      "name": "POWER_BUTTON1",
      "pin": "V0",
      "direction": "both",
      "multi-action": [
        {
          "duration": 0,
          "action": "chassis on"
        },
        {
          "duration": 4000,
          "action": "chassis cycle"
        },
        {
          "duration": 8000,
          "action": "chassis off"
        }
      ]
    }
  ]
}