STRUCT DMA_CONTROLLER(9)

💅 struct dma_controller(9) — Kernel API Manual

okay so bestie, welcome to the struct dma_controller(9) page ✨ this is the kernel API manual and honestly it's giving "small struct, big job" energy.

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🌸 NAME 🌸

struct dma_controller — A DMA Controller. that's it, that's the name 🎀

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✨ SYNOPSIS ✨

here's the actual struct, copied exactly so you can trust it fr fr:

struct dma_controller {
    struct musb *musb;
    struct dma_channel      *(*channel_alloc)(struct dma_controller *,
struct musb_hw_ep *, u8 is_tx);
    void (*channel_release)(struct dma_channel *);
    int (*channel_program)(struct dma_channel *channel, u16 maxpacket,
u8 mode, dma_addr_t dma_addr, u32 length);
    int (*channel_abort)(struct dma_channel *);
    int (*is_compatible)(struct dma_channel *channel, u16 maxpacket,
void *buf, u32 length);
    void (*dma_callback)(struct dma_controller *);
 };

like, look at all those function pointers 💀 she's a struct full of callbacks and she knows it.

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👑 Members 👑

• musb — the usb controller. she's the main character this struct orbits around 💖
• channel_alloc — call this to allocate a DMA channel ✨
• channel_release — call this to release a DMA channel 🦋
• channel_abort — call this to abort a pending DMA transaction, returning it to FREE (but allocated) state. so like, it goes back to being free but it still exists, ok? don't get it twisted 🙈
• dma_callback — invoked on DMA completion, useful to run platform code such IRQ acknowledgment. that's literally what the page says, no cap 👀

ngl, channel_program and is_compatible are right there in the struct too, but this page doesn't tell us what they do 😭 don't come for me, i'm just the messenger.

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💜 Description 💜

Controllers manage dma channels. periodt. short, sweet, iconic 🌈

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⭐ SEE ALSO ⭐

• Kernel file ./drivers/usb/musb/musb_dma.h
• struct dma_channel(9)

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and that's the whole vibe check, bestie 🫶 this came to you from ./drivers/usb/musb, dated October 2026, and it's the struct dma_controller(9) page — mwah, go read musb_dma.h next 💅💖