i3c_master_set_info(9)

💅 i3c_master_set_info(9) 💅

okay bestie, welcome to the Kernel API Manual ✨ this is the page for i3c_master_set_info — she's a little function with big main character energy, and we're gonna get you two acquainted 🫶

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🌸 NAME 🌸

i3c_master_set_info — literally just sets the master device information, that's her whole job, and she does it slayfully 💖

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✨ SYNOPSIS ✨

int i3c_master_set_info (struct i3c_master_controller *master , const
       struct i3c_device_info *info );

no cap, that's the whole signature. returns an int, takes two pointers, done 🔥

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🎀 ARGUMENTS 🎀

• master — the master, aka the one actually sending frames on the bus 🚌 she's the main character here, respect her.
• info — the I3C device information. this is the tea she's about to drink ☕

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🦋 DESCRIPTION 🦋

okay so. this function sets the master device info. periodt. and here's the important bit: this should be called from i3c_master_controller_ops->bus_init — like, that's the designated spot, don't be out here calling her from random places 🙈

now, lowkey not every field in i3c_device_info is meaningful for a master device — some of them are just along for the ride. here's the list of fields you should have properly filled in, bestie, take notes 📝:

• i3c_device_info->dyn_addr
• i3c_device_info->bcr
• i3c_device_info->dcr
• i3c_device_info->pid
• i3c_device_info->hdr_cap — but ONLY if the I3C_BCR_HDR_CAP bit is set in i3c_device_info->bcr, iykyk 👑

⚠️ and this one's serious: this function must be called with the bus lock held in maintenance mode. not normal use mode, not vibes mode — maintenance mode. don't skip this, fr fr 💀

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⭐ RETURN ⭐

returns 0 if info contains valid information — and like, not every piece of information can be checked, but at minimum we can make sure info->dyn_addr and info->bcr are correct, so that's the vibe check she runs ✅

returns -EINVAL otherwise. so if you see that, something's off and it's giving "go fix your struct" energy 😭

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🌈 SEE ALSO 🌈

the whole friend group, in this exact order, no cap:

Kernel file ./drivers/i3c/master.c, i3c_bus_maintenance_lock(9), i3c_bus_maintenance_unlock(9), i3c_bus_normaluse_lock(9), i3c_bus_normaluse_unlock(9), i3c_master_queue_hotjoin(9), i3c_master_send_ccc_cmd_locked(9), i3c_master_get_free_addr(9), i3c_master_setaasa_locked(9), i3c_master_entdaa_locked(9), i3c_master_enec_disec_locked(9), i3c_master_disec_locked(9), i3c_master_enec_locked(9), i3c_master_defslvs_locked(9), i3c_master_reattach_i3c_dev_locked(9), i3c_master_has_wakeup_enabled_devs(9), i3c_master_dma_map_single(9), i3c_master_dma_unmap_single(9), i3c_master_bus_init(9), __i3c_master_add_i3c_dev_locked(9), i3c_master_add_i3c_dev_locked(9), i3c_master_do_daa_ext(9), i3c_master_do_daa(9), i3c_master_queue_ibi(9), i3c_generic_ibi_free_pool(9), i3c_generic_ibi_alloc_pool(9), i3c_generic_ibi_get_free_slot(9), i3c_generic_ibi_recycle_slot(9), i3c_master_register(9), i3c_master_unregister(9), i3c_dev_disable_ibi_locked(9), i3c_dev_enable_ibi_locked(9), i3c_dev_request_ibi_locked(9), i3c_dev_free_ibi_locked(9)

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and that's the page, bestie 💜 this masterpiece lives at ./drivers/i3c, dated October 2026 — go forth and call her from bus_init like a good kernel dev 🧚✨