ax_transfer_one(9)

💅 ax_transfer_one(9) — the Kernel API Manual glow-up

okay so bestie, welcome to the ax_transfer_one(9) page from the Kernel API Manual. this is the one that actually kicks off the SPI transfer. it's giving main character energy in the transfer pipeline, and we're gonna go through it together, no cap. 🦋

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✨ NAME ✨

ax_transfer_one — initiates the SPI transfer 💫

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🌸 SYNOPSIS 🌸

int ax_transfer_one (struct spi_controller *ctlr , struct spi_device
*spi , struct spi_transfer *transfer );

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🎀 ARGUMENTS 🎀

• ctlr — pointer to the spi_controller structure. like, the controller in charge, the boss of the bus 👑
• spi — pointer to the spi_device structure. the actual device we're talking to 🫶
• transfer — pointer to the spi_transfer structure, which is literally the little info packet telling you all about the next transfer's parameters 📦

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🔥 DESCRIPTION 🔥

so what does it do, you ask? it fills the TX FIFO, starts the SPI transfer, and then returns a positive transfer count — and the reason it returns positive is so that core will wait for completion. that's the whole vibe check. the way it sets everything up and hands off the waiting duty to core… obsessed. ✨

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⭐ RETURN ⭐

number of bytes transferred in the last transfer. a little number, a lot of meaning 💖

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🧚 SEE ALSO 🧚

bestie, this is the whole squad, all hanging out in the kernel file ./drivers/spi/spi-axiado.c:

• ax_spi_read(9)
• ax_spi_write(9)
• ax_spi_write_b(9)
• ax_spi_init_hw(9)
• ax_spi_chipselect(9)
• ax_spi_config_clock_mode(9)
• ax_spi_config_clock_freq(9)
• ax_spi_setup_transfer(9)
• ax_spi_fill_tx_fifo(9)
• ax_spi_get_rx_byte_for_irq(9)
• ax_spi_process_rx_and_finalize(9)
• ax_spi_irq(9)
• ax_prepare_transfer_hardware(9)
• ax_unprepare_transfer_hardware(9)
• ax_spi_detect_fifo_depth(9)
• ax_spi_get_rx_byte(9)
• ax_spi_probe(9)
• ax_spi_remove(9)
• ax_spi_suspend(9)
• ax_spi_resume(9)
• ax_spi_runtime_resume(9)
• ax_spi_runtime_suspend(9)

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go read them all, iykyk 🫶

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and that's the page!! sign-off time: this lil beauty lives under ./drivers/spi, dated October 2026, and it ate, no notes. periodt 💅🌈