cti_read_osc_freq(9)

💅 cti_read_osc_freq — NAME ✨

okay so this is cti_read_osc_freq from the Kernel API Manual (section 9, bestie, we're in kernel-land now 🧚), and it does exactly one iconic thing: it reads the UART oscillator frequency out of the EEPROM. that's it. that's the whole vibe check. 🎀

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🌸 SYNOPSIS 🌸

int cti_read_osc_freq (struct exar8250 *priv , u8 eeprom_offset );

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🦋 ARGUMENTS 🦋

• priv — the device's private structure. like its little personal diary of state, y'know? 💖
• eeprom_offset — the offset where the oscillator frequency is stored. literally just tell it where in the EEPROM the number lives and it'll go get it 🫶

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✨ DESCRIPTION ✨

so here's the tea ☕ — CTI XR17x15X and XR17V25X cards have the serial board's oscillator frequency stored in the EEPROM. like, physically chilling in there. so this function goes and reads it, slay 💅

meanwhile FPGA and XR17V35X based cards? they don't do that — they use the PCI/PCIe clock instead. different vibe entirely, no EEPROM peek needed. iykyk 🔥

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💜 RETURN 💜

• the frequency on success — we ate and left no crumbs 👑
• a negative error code on failure — not the main character moment we wanted 😭

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🌈 SEE ALSO 🌈

• Kernel file ./drivers/tty/serial/8250/8250_exar.c
• struct exar8250_board(9)
• exar_mpio_config_output(9)
• _exar_mpio_set(9)
• cti_tristate_disable(9)
• cti_plx_int_enable(9)
• cti_get_port_type_xr17c15x_xr17v25x(9)
• cti_get_port_type_fpga(9)
• cti_get_port_type_xr17v35x(9)

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okay bye bestie, go read some EEPROMs responsibly 🍓💀 — this little page lives in ./drivers/tty/serial/8250, and it's dated October 2026 ⭐💖