pdc_dt_read(9)

💅 pdc_dt_read(9) — like, the Kernel API Manual page, bestie 🎀

okay so real quick: this is pdc_dt_read(9) from the Kernel API Manual, and it's basically the little gremlin function that goes and asks the device tree for its whole personality ✨

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🌸 NAME 🌸

pdc_dt_read — read application-specific data from the device tree, no cap 🧚

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✨ SYNOPSIS ✨

int pdc_dt_read (struct platform_device *pdev , struct pdc_state *pdcs
);

like yes that's the whole signature, she's lowkey tiny but she matters 💅

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🦋 ARGUMENTS 🦋

• pdev — the platform device, aka the actual thingy we're snooping on 💖
• pdcs — the PDC state, the vibe-holder where the answers get stashed 🫶

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👑 DESCRIPTION 👑

so what does she actually do? two things, and honestly both are iconic:

• she reads the number of bytes of receive status that come before each received frame 📥✨
• and she reads whether transmit and received frames should be preceded by an 8-byte BCM header 🎀 (yes, 8-byte, exactly 8, don't come for me)

that's it. that's the whole job. device tree in, application-specific data out, main character energy only 🔥

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⭐ RETURN ⭐

• 0 — slay, it worked ✨
• -ENODEV — the device wasn't available, and we're 😭 about it

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💜 SEE ALSO 💜

first up, the kernel file this diva lives in: ./drivers/mailbox/bcm-pdc-mailbox.c 📁💖

and then the whole friend group, fr fr:

• pdc_setup_debugfs(9)
• pdc_build_rxd(9)
• pdc_build_txd(9)
• pdc_receive_one(9)
• pdc_receive(9)
• pdc_tx_list_sg_add(9)
• pdc_tx_list_final(9)
• pdc_rx_list_init(9)
• pdc_rx_list_sg_add(9)
• pdc_irq_handler(9)
• pdc_work_cb(9)
• pdc_ring_init(9)
• pdc_desc_count(9)
• pdc_rings_full(9)
• pdc_last_tx_done(9)
• pdc_send_data(9)
• pdc_hw_init(9)
• pdc_hw_disable(9)
• pdc_rx_buf_pool_create(9)
• pdc_interrupts_init(9)
• pdc_mb_init(9)
• pdc_probe(9)

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ngl bestie, this page was brought to you by ./drivers/mailbox and dated October 2026 — go drink some water and read your device tree 🌈💀🫶