sifive_seria..._txfifo_full(9)

💅 sifive_seria..._txfifo_full(9)

okay so bestie, we're deep in the Kernel API Manual today and this one is a little function from the sifive serial driver that you're gonna be obsessed with. it's literally called sifive_serial_is_txfifo_full and yeah, the page title is truncated with ... because the kernel devs are dramatic like that. iykyk. 🎀

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✨ NAME ✨

sifive_serial_is_txfifo_full — is the TXFIFO full? that's it. that's the whole question. 💅

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🌸 SYNOPSIS 🌸

int sifive_serial_is_txfifo_full (struct sifive_serial_port *ssp );

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🦋 ARGUMENTS 🦋

• ssp — pointer to a struct sifive_serial_port. yes bestie, it's that struct. the main character. 👑

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💖 DESCRIPTION 💖

okay so what this does is it reads the transmit FIFO "full" bit. simple as that. ✨

if the TX FIFO is full, you get a non-zero value back. if there's still space left, you get zero. slay.

the whole vibe of this function is prevention — it's intended to be used to prevent writes to the TX FIFO when it's full. like a little bouncer at the club door checking if there's room. 🫶 no cap, that's genuinely what it's for.

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⭐ RETURN ⭐

• SIFIVE_SERIAL_TXDATA_FULL_MASK (non-zero) if the transmit FIFO is full 😭
• 0 if space remains 🎉

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🌈 SEE ALSO 🌈

Kernel file ./drivers/tty/serial/sifive.c plus this whole squad of friends:

• struct sifive_serial_port(9)
• __ssp_early_writel(9)
• __ssp_early_readl(9)
• __ssp_writel(9)
• __ssp_readl(9)
• __ssp_transmit_char(9)
• __ssp_transmit_chars(9)
• __ssp_enable_txwm(9)
• __ssp_enable_rxwm(9)
• __ssp_disable_txwm(9)
• __ssp_disable_rxwm(9)
• __ssp_receive_char(9)
• __ssp_receive_chars(9)
• __ssp_update_div(9)
• __ssp_update_baud_rate(9)
• __ssp_set_stop_bits(9)
• __ssp_wait_for_xmitr(9)
• sifive_serial_clk_notifier(9)

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ngl the amount of __ssp_ functions here is giving "group chat with 18 people and every single one of them has the same name energy" 💀 but they're all iconic in their own way, go read them.

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and that's the page bestie! 🧚 this little gem lives in ./drivers/tty/serial and it was dated October 2026 — yes, 2026, we're manifesting the future 🔮💜. so cute, so documented. periodt. 💅✨