Documentation/hwmon/da9055.rst

File Facts

System

Linux kernel

Corpus path

Documentation/hwmon/da9055.rst

Extension

.rst

Size

1698 bytes

Lines

58

Domain

Support Tooling And Documentation

Bucket

Documentation

Inferred role

Support Tooling And Documentation: documentation

Status

atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

• Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

• No C-style include directives detected by the generator.

Detected Declarations

• No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

Kernel driver da9055
====================

Supported chips:
  * Dialog Semiconductors DA9055 PMIC

    Prefix: 'da9055'

    Datasheet: Datasheet is not publicly available.

Authors: David Dajun Chen <dchen@diasemi.com>

Description
-----------

The DA9055 provides an Analogue to Digital Converter (ADC) with 10 bits
resolution and track and hold circuitry combined with an analogue input
multiplexer. The analogue input multiplexer will allow conversion of up to 5
different inputs. The track and hold circuit ensures stable input voltages at
the input of the ADC during the conversion.

The ADC is used to measure the following inputs:

- Channel 0: VDDOUT - measurement of the system voltage
- Channel 1: ADC_IN1 - high impedance input (0 - 2.5V)
- Channel 2: ADC_IN2 - high impedance input (0 - 2.5V)
- Channel 3: ADC_IN3 - high impedance input (0 - 2.5V)
- Channel 4: Internal Tjunc. - sense (internal temp. sensor)

By using sysfs attributes we can measure the system voltage VDDOUT,
chip junction temperature and auxiliary channels voltages.

Voltage Monitoring
------------------

Voltages are sampled in a AUTO mode it can be manually sampled too and results
are stored in a 10 bit ADC.

The system voltage is calculated as:

	Milli volt = ((ADC value * 1000) / 85) + 2500

The voltages on ADC channels 1, 2 and 3 are calculated as:

	Milli volt = (ADC value * 1000) / 102

Temperature Monitoring
----------------------

Temperatures are sampled by a 10 bit ADC.  Junction temperatures
are monitored by the ADC channels.

The junction temperature is calculated:

	Degrees celsius = -0.4084 * (ADC_RES - T_OFFSET) + 307.6332

The junction temperature attribute is supported by the driver.

Annotation

• Atlas domain: Support Tooling And Documentation / Documentation.
• Implementation status: atlas-only.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.