drivers/dma/at_xdmac.c

File Facts

System

Linux kernel

Corpus path

drivers/dma/at_xdmac.c

Extension

.c

Size

77738 bytes

Lines

2511

Domain

Driver Families

Bucket

drivers/dma

Inferred role

Driver Families: exported/initcall integration point

Status

integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

• Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
• Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Touches IRQ or DMA behavior; this matters for the representative real-device path.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• asm/barrier.h
• dt-bindings/dma/at91.h
• linux/clk.h
• linux/dmaengine.h
• linux/dmapool.h
• linux/interrupt.h
• linux/irq.h
• linux/kernel.h
• linux/list.h
• linux/module.h
• linux/of_dma.h
• linux/of_platform.h
• linux/platform_device.h
• linux/pm.h
• linux/pm_runtime.h
• dmaengine.h

Detected Declarations

• struct at_xdmac_layout
• struct at_xdmac_chan
• struct at_xdmac
• struct at_xdmac_lld
• struct at_xdmac_desc
• enum atc_status
• function at_xdmac_chan_is_cyclic
• function at_xdmac_chan_is_paused
• function at_xdmac_chan_is_paused_internal
• function at_xdmac_chan_is_peripheral_xfer
• function at_xdmac_get_dwidth
• function at_xdmac_runtime_suspend_descriptors
• function list_for_each_entry_safe
• function at_xdmac_runtime_resume_descriptors
• function list_for_each_entry_safe
• function at_xdmac_chan_is_enabled
• function at_xdmac_off
• function list_for_each_entry_safe
• function at_xdmac_start_xfer
• function at_xdmac_tx_submit
• function at_xdmac_init_used_desc
• function at_xdmac_queue_desc
• function at_xdmac_increment_block_count
• function at_xdmac_compute_chan_conf
• function at_xdmac_check_slave_config
• function at_xdmac_set_slave_config
• function at_xdmac_prep_slave_sg
• function at_xdmac_prep_dma_cyclic
• function at_xdmac_align_width
• function at_xdmac_interleaved_queue_desc
• function at_xdmac_prep_interleaved
• function at_xdmac_prep_dma_memcpy
• function at_xdmac_prep_dma_memset
• function at_xdmac_prep_dma_memset_sg
• function elements
• function yet
• function at_xdmac_tx_status
• function at_xdmac_advance_work
• function at_xdmac_handle_cyclic
• function at_xdmac_handle_error
• function at_xdmac_tasklet
• function at_xdmac_interrupt
• function at_xdmac_issue_pending
• function at_xdmac_device_config
• function at_xdmac_device_pause_set
• function at_xdmac_device_pause_internal
• function at_xdmac_device_pause
• function at_xdmac_device_resume_internal

Annotated Snippet

subsys_initcall(at_xdmac_init);

static void __exit at_xdmac_exit(void)
{
	platform_driver_unregister(&at_xdmac_driver);
}
module_exit(at_xdmac_exit);

MODULE_DESCRIPTION("Atmel Extended DMA Controller driver");
MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches@atmel.com>");
MODULE_LICENSE("GPL");

Annotation

• Immediate include surface: `asm/barrier.h`, `dt-bindings/dma/at91.h`, `linux/clk.h`, `linux/dmaengine.h`, `linux/dmapool.h`, `linux/interrupt.h`, `linux/irq.h`, `linux/kernel.h`.
• Detected declarations: `struct at_xdmac_layout`, `struct at_xdmac_chan`, `struct at_xdmac`, `struct at_xdmac_lld`, `struct at_xdmac_desc`, `enum atc_status`, `function at_xdmac_chan_is_cyclic`, `function at_xdmac_chan_is_paused`, `function at_xdmac_chan_is_paused_internal`, `function at_xdmac_chan_is_peripheral_xfer`.
• Atlas domain: Driver Families / drivers/dma.
• Implementation status: integration implementation candidate.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
• IRQ or DMA behavior appears here, which is relevant to the selected PCIe/NVMe device path.

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.