STRUCT NVMEM_CONFIG(9)

🎀 struct nvmem_config(9) 🎀

okay so welcome to the Kernel API Manual, bestie 💖 this is the page for struct nvmem_config and honestly? it's giving "how to build an NVMEM device from scratch" and I'm obsessed.

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✨ NAME ✨

struct nvmem_config — the configuration struct for an NVMEM device 🦋

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🌸 SYNOPSIS 🌸

struct nvmem_config {
    struct device           *dev;
    const char              *name;
    int id;
    struct module           *owner;
    const struct nvmem_cell_info    *cells;
    int ncells;
    bool add_legacy_fixed_of_cells;
    void (*fixup_dt_cell_info)(struct nvmem_device *nvmem, struct nvmem_cell_info *cell);
    const struct nvmem_keepout *keepout;
    unsigned int            nkeepout;
    enum nvmem_type         type;
    bool read_only;
    bool root_only;
    bool ignore_wp;
    struct nvmem_layout     *layout;
    struct device_node      *of_node;
    nvmem_reg_read_t reg_read;
    nvmem_reg_write_t reg_write;
    int size;
    int word_size;
    int stride;
    void *priv;
    bool compat;
    struct device           *base_dev;
 };

like, that's the whole blueprint, no cap 🔥

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💅 MEMBERS 💅

bestie there are 24 of these and yes we're doing all of them, grab a snack 🍓

• dev — the parent device. your main character's parent, basically.
• name — an optional name. optional but iconic ✨
• id — an optional device ID, used up in the full name. heads up: this gets ignored if name is NULL 💀
• owner — pointer to the exporter module. it's for refcounting, iykyk.
• cells — optional array of pre-defined NVMEM cells 🧚
• ncells — the number of elements in cells. count 'em, periodt.
• add_legacy_fixed_of_cells — read fixed NVMEM cells from the old OF syntax. retro vibes ngl.
• fixup_dt_cell_info — gets called before a cell is added. use it to modify the nvmem_cell_info. lowkey a lil hook 🫶
• keepout — optional array of keepout ranges, sorted ascending by start. don't forget the sort, bestie, it matters 🙈
• nkeepout — the number of elements in the keepout array.
• type — the type of the nvmem storage.
• read_only — device is read-only. look but don't touch 💅
• root_only — device is accessibly to root only 👑 (yes the original says "accessibly", we love a typo moment, keeping it fr fr)
• ignore_wp — the Write Protect pin is managed by the provider.
• layout — the fixed layout associated with this nvmem device.
• of_node — if given, this will be used instead of the parent's of_node. it overrides, no questions asked.
• reg_read — callback to read data; return zero if successful ⭐
• reg_write — callback to write data; return zero if successful ⭐
• size — device size.
• word_size — minimum read/write access granularity.
• stride — minimum read/write access stride.
• priv — user context passed to the read/write callbacks. your personal little bag of stuff 🎀
• compat — the compat field, sitting right there in the struct 🙈
• base_dev — the base device pointer. also just vibing in the struct 🦋

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🦋 NOTE 🦋

A default "nvmem<id>" name will be assigned to the device if no name is specified in its configuration. In such case <id> is generated with ida_alloc and the provided id field is ignored 😭 (so don't bother setting it, it's not listening).

Specifying name and setting id to -1 implies a unique device whose name is provided as-is (kept unaltered). literally untouched, kept exactly how you wrote it, main character energy 👑

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🌈 SEE ALSO 🌈

• Kernel file ./include/linux/nvmem-provider.h
• struct nvmem_keepout(9)
• struct nvmem_cell_info(9)
• struct nvmem_layout(9)
• of_nvmem_layout_get_container(9)

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and that's the page, bestie 💜 it lives at ./include/linux and it's dated October 2026 — go off, struct, slay, periodt 🌸✨🔥