STRUCT CDNS2_EP0_REGS(9)

💜 struct cdns2_ep0_regs(9) — the Kernel API Manual glow-up 🎀

okay so bestie, welcome to the Kernel API Manual for struct cdns2_ep0_regs, and trust me when I say this one is literally the main character of endpoint 0 💅

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✨ NAME ✨

struct cdns2_ep0_regs — the endpoint 0 related registers, all cozy in one struct 🫶

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🌸 SYNOPSIS 🌸

bestie. look at this layout. it's giving memory-mapped register realness ✨ copy it exactly, no edits, no cap:

struct cdns2_ep0_regs {
    __u8 rxbc;
    __u8 txbc;
    __u8 cs;
    __u8 reserved1[4];
    __u8 fifo;
    __le32 reserved2[94];
    __u8 setupdat[8];
    __u8 reserved4[88];
    __u8 maxpack;
 };

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🦋 Members 🦋

okay so let's do a little member-by-member vibe check, one at a time, because every single one matters 💖

• rxbc — the receive (OUT) 0 endpoint byte count register. how many bytes came in? it knows. 👑
• txbc — the transmit (IN) 0 endpoint byte count register. how many bytes are headed out? also knows. 💫
• cs — the 0 endpoint control and status register. the drama. the state. the icon. 🔥
• reserved1 — reserved 🙈 hands off, bestie.
• fifo — the 0 endpoint fifo register. data goes in, data comes out, iconic behavior 🍓
• reserved2 — reserved 🙈 again. like, __le32 reserved2[94] worth of "not for you."
• setupdat — the SETUP data register. setupdat[8], eight glorious bytes of setup-ness ✨
• reserved4 — reserved 🙈 (yes, it skipped 3 in the name, no we will not be fixing it, we love her exactly as she is 💅)
• maxpack — the 0 endpoint max packet size. the limit. the boundary. the moment of truth 🌈

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👑 SEE ALSO 👑

go read these next, fr fr, they're all in the kernel file ./drivers/usb/gadget/udc/cdns2/cdns2-gadget.h and they're all besties:

• struct cdns2_epx_base(9)
• struct cdns2_epx_regs(9)
• struct cdns2_interrupt_regs(9)
• struct cdns2_usb_regs(9)
• struct cdns2_adma_regs(9)
• struct cdns2_trb(9)
• struct cdns2_ring(9)
• struct cdns2_endpoint(9)
• struct cdns2_request(9)
• struct cdns2_device(9)

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🫶 a lil reminder: the reserved members are reserved for a reason — don't go poking them and pretending you didn't, bestie 😭

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and that's the page!! slay 💖 this whole thing lives over in ./drivers/usb/gadget/udc/cdns2, dated October 2026, and yes she's still called struct cdns2_ep0_regs(9) — periodt ✨🎀