regmap_init_mmio_clk(9)

💅 regmap_init_mmio_clk — kernel API manual, but make it cute

okay so bestie, this is regmap_init_mmio_clk(9) from the Kernel API Manual and it is literally the moment your register map gets a clock. we're doing this together, no cap.

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✨ NAME ✨

regmap_init_mmio_clk — Initialise register map with register clock

like, it sets up your register map and it brings the register clock along for the ride 🎀

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🌸 SYNOPSIS 🌸

regmap_init_mmio_clk (dev , clk_id , regs , config );

that's the whole vibe. four things in, one regmap (or an error) out 💖

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🦋 ARGUMENTS 🦋

• dev — Device that will be interacted with. the main character we're doing all this for 👑
• clk_id — register clock consumer ID. yes, the clock needs a name to be looked up by, iykyk ⏰
• regs — Pointer to memory-mapped IO region. the actual memory-mapped real estate, mmio and all 🗺️
• config — Configuration for register map. all the settings, all the choices, it's giving customization ✨

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💜 DESCRIPTION 💜

okay so the important bit, and I need you to hear me on this: The return value will be an ERR_PTR on error or a valid pointer to a struct regmap.

so like — check it. don't just assume it worked. if it's bad news it comes back as an ERR_PTR, if it's good news it's a real live struct regmap pointer 🫶

Also: this implies 'fast_io'. that's it, that's the note. it's implied. periodt 💅

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🔥 SEE ALSO 🔥

bestie there are SO many siblings, buckle up:

• Kernel file ./include/linux/regmap.h
• struct reg_default(9)
• struct reg_sequence(9)
• regmap_read_poll_timeout(9)
• regmap_read_poll_timeout_atomic(9)
• regmap_field_read_poll_timeout(9)
• struct regmap_range(9)
• struct regmap_access_table(9)
• struct regmap_config(9)
• struct regmap_range_cfg(9)
• struct regmap_sdw_mbq_cfg(9)
• struct regmap_bus(9)
• regmap_init(9)
• regmap_init_i2c(9)
• regmap_init_mdio(9)
• regmap_init_sccb(9)
• regmap_init_slimbus(9)
• regmap_init_spi(9)
• regmap_init_spmi_base(9)
• regmap_init_spmi_ext(9)
• regmap_init_w1(9)
• regmap_init_mmio(9)
• regmap_init_ac97(9)
• regmap_init_sdw(9)
• regmap_init_sdw_mbq(9)
• regmap_init_sdw_mbq_cfg(9)
• regmap_init_i3c(9)
• regmap_init_spi_avmm(9)
• regmap_init_fsi(9)
• devm_regmap_init(9)
• devm_regmap_init_i2c(9)
• devm_regmap_init_mdio(9)
• devm_regmap_init_sccb(9)
• devm_regmap_init_spi(9)
• devm_regmap_init_spmi_base(9)
• devm_regmap_init_spmi_ext(9)
• devm_regmap_init_w1(9)
• devm_regmap_init_mmio_clk(9)
• devm_regmap_init_mmio(9)
• devm_regmap_init_ac97(9)
• devm_regmap_init_sdw(9)
• devm_regmap_init_sdw_mbq(9)
• devm_regmap_init_sdw_mbq_cfg(9)
• devm_regmap_init_slimbus(9)
• devm_regmap_init_i3c(9)
• devm_regmap_init_spi_avmm(9)
• devm_regmap_init_fsi(9)
• struct reg_field(9)
• struct regmap_irq_type(9)
• struct regmap_irq(9)
• struct regmap_irq_chip(9)

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lowkey the whole regmap family is iconic and this one is just the mmio + clock version. go read the rest, you'll be obsessed 🌈

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that's the page!! sources say it lives in ./include/linux, dated October 2026, and it goes by regmap_init_mmio_clk(9) — mwah, bye bestie 💋💖