Overview

Informative

What the LIN driver is, its boundaries, and where it sits. Non-binding orientation; the normative contract is in Lin — Requirements. The driver builds on the shared foundation (type system, error model, naming, memory mapping) in General.

In one sentence: the LIN driver (LinDrv) provides a thin, portable abstraction over a LIN controller operating as a responder — it receives frame headers, transmits or receives the response, manages per-channel wakeup/sleep, and reports events to the upper layer (LinIf).

What it does

  • Brings the driver and its channels up and down, and manages per-channel power state (sleep / operational).

  • Receives a LIN header (break + sync + protected identifier) and, per the upper layer’s decision, transmits, receives, or ignores the response.

  • Detects and transmits wakeup pulses, and puts a channel into a logical sleep state.

  • Handles events in either interrupt or polling mode, per channel, and reports them through the LinIf_On* callbacks.

What it does not do

  • Responder mode only. The driver does not implement commander (master) behavior: it does not run a schedule table or originate frame headers. See Design Decisions.

  • No responder node position detection.

  • No system-resource setup. Input clock, port pins, and interrupt controller are prerequisites another module configures before Lin_Init.

  • No software PID-parity verification where the hardware cannot provide it.

Where it sits

        flowchart TB
   UL["Upper layer (LinIf)"]
   DRV["Chiisai LIN Driver"]
   HWA["Hardware abstraction<br/>(clock, port, interrupt)"]
   HW["LIN controller / transceiver"]

   UL -->|"Lin_Init, Lin_Wakeup,<br/>Lin_GoToSleepInternal, ..."| DRV
   DRV -->|"LinIf_On* callbacks<br/>(OnHeader, OnReception,<br/>OnTransmission, OnError, OnWakeup)"| UL
   DRV --> HWA
   HWA --> HW

   classDef driver fill:#FEDCD2,stroke:#c66,stroke-width:2px;
   class DRV driver;

The hardware-abstraction layer (clock, port pins, interrupt controller) is set up by other modules before Lin_Init; the LIN driver assumes it is ready.

Dependencies

Depends on

For

System resources (clock, port, interrupt)

Bit timing, pin routing, and interrupt configuration for the LIN controller. These must be set up by another module before Lin_Init.

Expected upper-layer interfaces

The callbacks and services the driver calls back into (LinIf_On*, LogM_Report, and optional critical-section services). See API Reference → Expected interfaces.

The shared foundation

The common type system, compiler abstraction, error model, naming scheme, and memory mapping defined in General.

References

No.

Document

[1]

The Chiisai HAL General part — the shared contract this module builds on.

[2]

ISO 17987 (all parts) — Road vehicles — Local Interconnect Network (LIN).