drivers/dma/dma-jz4780.c

File Facts

System

Linux kernel

Corpus path

drivers/dma/dma-jz4780.c

Extension

.c

Size

32228 bytes

Lines

1147

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/clk.h
• linux/dmapool.h
• linux/dma-mapping.h
• linux/init.h
• linux/interrupt.h
• linux/module.h
• linux/of.h
• linux/of_dma.h
• linux/platform_device.h
• linux/slab.h
• dmaengine.h
• virt-dma.h

Detected Declarations

• struct jz4780_dma_hwdesc
• struct jz4780_dma_desc
• struct jz4780_dma_chan
• struct jz4780_dma_soc_data
• struct jz4780_dma_dev
• struct jz4780_dma_filter_data
• function jz4780_dma_chn_readl
• function jz4780_dma_chn_writel
• function jz4780_dma_ctrl_readl
• function jz4780_dma_ctrl_writel
• function jz4780_dma_chan_enable
• function jz4780_dma_chan_disable
• function jz4780_dma_desc_alloc
• function jz4780_dma_desc_free
• function jz4780_dma_transfer_size
• function jz4780_dma_setup_hwdesc
• function to
• function jz4780_dma_begin
• function jz4780_dma_issue_pending
• function jz4780_dma_terminate_all
• function jz4780_dma_synchronize
• function jz4780_dma_config
• function jz4780_dma_desc_residue
• function jz4780_dma_tx_status
• function jz4780_dma_chan_irq
• function jz4780_dma_irq_handler
• function for_each_set_bit
• function jz4780_dma_alloc_chan_resources
• function jz4780_dma_free_chan_resources
• function jz4780_dma_filter_fn
• function jz4780_dma_probe
• function jz4780_dma_remove
• function jz4780_dma_init
• function jz4780_dma_exit
• module init jz4780_dma_init

Annotated Snippet

subsys_initcall(jz4780_dma_init);

static void __exit jz4780_dma_exit(void)
{
	platform_driver_unregister(&jz4780_dma_driver);
}
module_exit(jz4780_dma_exit);

MODULE_AUTHOR("Alex Smith <alex@alex-smith.me.uk>");
MODULE_DESCRIPTION("Ingenic JZ4780 DMA controller driver");
MODULE_LICENSE("GPL");

Annotation

• Immediate include surface: `linux/clk.h`, `linux/dmapool.h`, `linux/dma-mapping.h`, `linux/init.h`, `linux/interrupt.h`, `linux/module.h`, `linux/of.h`, `linux/of_dma.h`.
• Detected declarations: `struct jz4780_dma_hwdesc`, `struct jz4780_dma_desc`, `struct jz4780_dma_chan`, `struct jz4780_dma_soc_data`, `struct jz4780_dma_dev`, `struct jz4780_dma_filter_data`, `function jz4780_dma_chn_readl`, `function jz4780_dma_chn_writel`, `function jz4780_dma_ctrl_readl`, `function jz4780_dma_ctrl_writel`.
• 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.