drivers/dma/txx9dmac.c

File Facts

System

Linux kernel

Corpus path

drivers/dma/txx9dmac.c

Extension

.c

Size

34307 bytes

Lines

1305

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

• linux/dma-mapping.h
• linux/init.h
• linux/interrupt.h
• linux/io.h
• linux/module.h
• linux/platform_device.h
• linux/slab.h
• linux/scatterlist.h
• dmaengine.h
• txx9dmac.h

Detected Declarations

• function Copyright
• function channel64_readl
• function channel64_write_CHAR
• function channel64_clear_CHAR
• function channel_read_CHAR
• function channel_write_CHAR
• function txd_to_txx9dmac_desc
• function desc_read_CHAR
• function desc_write_CHAR
• function txx9dmac_sync_desc_for_cpu
• function txx9dmac_desc_put
• function txx9dmac_dump_regs
• function txx9dmac_reset_chan
• function txx9dmac_dostart
• function txx9dmac_descriptor_complete
• function txx9dmac_dequeue
• function txx9dmac_complete_all
• function txx9dmac_dump_desc
• function txx9dmac_handle_error
• function txx9dmac_scan_descriptors
• function list_for_each_entry_safe
• function list_for_each_entry
• function txx9dmac_chan_tasklet
• function txx9dmac_chan_interrupt
• function txx9dmac_tasklet
• function txx9dmac_interrupt
• function txx9dmac_tx_submit
• function txx9dmac_prep_dma_memcpy
• function txx9dmac_prep_slave_sg
• function for_each_sg
• function txx9dmac_terminate_all
• function txx9dmac_tx_status
• function txx9dmac_chain_dynamic
• function txx9dmac_issue_pending
• function txx9dmac_alloc_chan_resources
• function txx9dmac_free_chan_resources
• function list_for_each_entry_safe
• function txx9dmac_off
• function txx9dmac_chan_probe
• function txx9dmac_chan_remove
• function txx9dmac_probe
• function txx9dmac_remove
• function txx9dmac_shutdown
• function txx9dmac_suspend_noirq
• function txx9dmac_resume_noirq
• function txx9dmac_init
• function txx9dmac_exit
• module init txx9dmac_init

Annotated Snippet

module_init(txx9dmac_init);

static void __exit txx9dmac_exit(void)
{
	platform_driver_unregister(&txx9dmac_chan_driver);
	platform_driver_unregister(&txx9dmac_driver);
}
module_exit(txx9dmac_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("TXx9 DMA Controller driver");
MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
MODULE_ALIAS("platform:txx9dmac");
MODULE_ALIAS("platform:txx9dmac-chan");

Annotation

• Immediate include surface: `linux/dma-mapping.h`, `linux/init.h`, `linux/interrupt.h`, `linux/io.h`, `linux/module.h`, `linux/platform_device.h`, `linux/slab.h`, `linux/scatterlist.h`.
• Detected declarations: `function Copyright`, `function channel64_readl`, `function channel64_write_CHAR`, `function channel64_clear_CHAR`, `function channel_read_CHAR`, `function channel_write_CHAR`, `function txd_to_txx9dmac_desc`, `function desc_read_CHAR`, `function desc_write_CHAR`, `function txx9dmac_sync_desc_for_cpu`.
• 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.