stm32_firewall_get_firewall(9)

🌸 stm32_firewall_get_firewall — Kernel API Manual 🌸

okay so bestie, you're looking at the kernel API manual page for stm32_firewall_get_firewall, and honestly? it's giving "let me introduce you to the firewalls" energy. it's a function that gets the firewall(s) associated to a given device, periodt 💅

✨ NAME ✨

stm32_firewall_get_firewall — get the firewall(s) associated with a given device 🔥

here's the tea on how the parsing works, and you literally cannot skip this part:

• the firewall controller reference is always the first argument of each of the access-controller property entries 🥇
• the firewall ID is always the second argument of each of the access-controller property entries 🥈
• if there's no argument linked to the phandle, then the firewall ID field is set to U32_MAX, which is an invalid ID 💀 (yeah, that's the "nobody's home" sentinel, don't come for me)

🦋 SYNOPSIS 🦋

int stm32_firewall_get_firewall (struct device_node *np,
                                 struct stm32_firewall *firewall,
                                 unsigned int nb_firewall);

🎀 ARGUMENTS 🎀

• np — the device node to parse 🌳 this is the thing you're snooping through to find your firewalls
• firewall — array of firewall references 💖 it's a whole little squad of them, not just one
• nb_firewall — number of firewall references to get. Must be at least 1. 👑 no zero, no negative, we're not doing that here

💜 DESCRIPTION 💜

so what does it actually return? here's the vibe check:

• returns 0 on success — slay, everything worked ✨
• returns -ENODEV if there's no match with a firewall controller 😭 rude but fair
• or an appropriate errno code if some other error occurred 🫶

that's literally it, bestie. it parses, it matches, it hands you back your firewall references. iconic behavior honestly.

quick reminder: nb_firewall must be at least 1 — that's not a suggestion, that's the rule 🙈

🌈 SEE ALSO 🌈

• kernel file ./include/linux/bus/stm32_firewall_device.h 📁
• struct stm32_firewall(9)
• stm32_firewall_grant_access(9)
• stm32_firewall_release_access(9)
• stm32_firewall_grant_access_by_id(9)
• stm32_firewall_release_access_by_id(9)
• stm32_firewall_get_grant_all_access(9)

go read those too, iykyk 💅

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and that's a wrap, bestie! 🎀 this little masterpiece lives over in ./include/linux/bus, dated October 2026, and it's filed under stm32_firewall_get_firewall(9). mwah, go forth and get those firewalls 🦋💖