prcmu_abb_write(9)

💫 prcmu_abb_write(9) — the manual page, but make it group chat 💫

okay bestie, so this is a page from the Kernel API Manual, section 9, and it's all about prcmu_abb_write. it's giving very niche kernel lore, but we're gonna get through it together, i promise 🫶

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✨ NAME ✨

prcmu_abb_write — literally just writes register value(s) to the ABB 💅 no cap, that's the whole vibe.

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🌸 SYNOPSIS 🌸

int prcmu_abb_write(u8 slave, u8 reg, u8 *value, u8 size);

like, that's the signature, and yes it's an int return, main character energy fr fr 🔥

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🎀 ARGUMENTS 🎀

• slave — the I2C slave address. that's the address, bestie, don't @ me 🙈
• reg — the (start) register address. it's the start one, key detail, iykyk.
• value — the value(s) you're writing. plural! it's a pointer, it can carry multiple vibes 💖
• size — the number of registers to write. how many are we doing? that's what size decides ✨

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🦋 DESCRIPTION 🦋

so the whole point: writes register value(s) to the ABB. that's it, that's the function 🫶

and here's the tea ☕: size has to be 1 for the current firmware version. like, it's not a suggestion, bestie, it's a hard requirement for the firmware as it stands rn 💀 don't be out here passing size = 2 thinking you're iconic, because the current firmware will simply not slay. lowkey important, highkey a vibe check on your args 🌈

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👑 SEE ALSO 👑

okay so this function runs with a whole friend group, and you should probably meet all of them. here's the full roster, no one left out, periodt 💅

the kernel file ./drivers/mfd/db8500-prcmu.c plus these absolute icons:

• prcmu_set_rc_a2p(9)
• prcmu_get_rc_p2a(9)
• prcmu_get_xp70_current_state(9)
• prcmu_config_clkout(9)
• db8500_prcmu_set_arm_opp(9)
• db8500_prcmu_get_arm_opp(9)
• db8500_prcmu_get_ddr_opp(9)
• db8500_prcmu_set_ape_opp(9)
• db8500_prcmu_get_ape_opp(9)
• db8500_prcmu_request_ape_opp_100_voltage(9)
• prcmu_release_usb_wakeup_state(9)
• db8500_prcmu_set_epod(9)
• prcmu_configure_auto_pm(9)
• db8500_prcmu_request_clock(9)
• prcmu_abb_read(9) — yes, the read counterpart, they're siblings 🥺
• prcmu_abb_write_masked(9)
• prcmu_ac_wake_req(9)
• prcmu_ac_sleep_req(9)
• db8500_prcmu_system_reset(9)
• db8500_prcmu_get_reset_code(9)
• db8500_prcmu_modem_reset(9)

like, that's a stacked lineup. ate and left no crumbs 👑

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and that's the whole page!! this one's sourced from ./drivers/mfd, version October 2026, and yeah, that's the date too — so consider this your cute little sign-off, bestie. go forth and write those ABB registers (with size = 1, obviously 💜). mwah 🧚‍♀️✨