drivers/dma/at_hdmac.c

File Facts

System

Linux kernel

Corpus path

drivers/dma/at_hdmac.c

Extension

.c

Size

65776 bytes

Lines

2285

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

• dt-bindings/dma/at91.h
• linux/bitfield.h
• linux/clk.h
• linux/dmaengine.h
• linux/dmapool.h
• linux/dma-mapping.h
• linux/interrupt.h
• linux/module.h
• linux/of.h
• linux/overflow.h
• linux/of_platform.h
• linux/of_dma.h
• linux/platform_device.h
• linux/slab.h
• dmaengine.h
• virt-dma.h

Detected Declarations

• struct at_lli
• struct atdma_sg
• struct at_desc
• struct at_dma_chan
• struct at_dma
• struct at_dma_platform_data
• struct at_dma_slave
• enum atc_status
• function convert_burst
• function convert_buswidth
• function vdbg_dump_regs
• function vdbg_dump_regs
• function atc_setup_irq
• function atc_enable_chan_irq
• function atc_disable_chan_irq
• function atc_chan_is_enabled
• function atc_chan_is_paused
• function atc_chan_is_cyclic
• function set_lli_eol
• function atc_get_xfer_width
• function atdma_lli_chain
• function atc_dostart
• function atdma_desc_free
• function atc_calc_bytes_left
• function Item
• function atc_get_residue
• function atc_handle_error
• function atdma_handle_chan_done
• function at_dma_interrupt
• function atc_prep_dma_interleaved
• function atc_prep_dma_memcpy
• function atdma_create_memset_lli
• function atc_prep_dma_memset
• function atc_prep_dma_memset_sg
• function for_each_sg
• function atc_prep_slave_sg
• function for_each_sg
• function for_each_sg
• function atc_dma_cyclic_check_values
• function atc_dma_cyclic_fill_desc
• function atc_prep_dma_cyclic
• function atc_config
• function atc_pause
• function atc_resume
• function atc_terminate_all
• function dma_async_is_complete
• function atc_issue_pending
• function atc_alloc_chan_resources

Annotated Snippet

subsys_initcall(at_dma_init);

static void __exit at_dma_exit(void)
{
	platform_driver_unregister(&at_dma_driver);
}
module_exit(at_dma_exit);

MODULE_DESCRIPTION("Atmel AHB DMA Controller driver");
MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>");
MODULE_AUTHOR("Tudor Ambarus <tudor.ambarus@microchip.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:at_hdmac");

Annotation

• Immediate include surface: `dt-bindings/dma/at91.h`, `linux/bitfield.h`, `linux/clk.h`, `linux/dmaengine.h`, `linux/dmapool.h`, `linux/dma-mapping.h`, `linux/interrupt.h`, `linux/module.h`.
• Detected declarations: `struct at_lli`, `struct atdma_sg`, `struct at_desc`, `struct at_dma_chan`, `struct at_dma`, `struct at_dma_platform_data`, `struct at_dma_slave`, `enum atc_status`, `function convert_burst`, `function convert_buswidth`.
• 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.