dwc2_force_mode(9)

💅 dwc2_force_mode(9) — like, the Kernel API Manual, bestie

okay so real talk, this one lives in the Kernel API Manual and it's called dwc2_force_mode(9) — say that three times fast, i dare you 🎀

✨ NAME ✨

dwc2_force_mode — literally forces the mode of the controller. that's it. that's the whole vibe. 👑

🌸 SYNOPSIS 🌸

void dwc2_force_mode (struct dwc2_hsotg *hsotg , bool host );

🦋 ARGUMENTS 🦋

• hsotg — the programming view of the DWC_otg controller. yes it's a struct dwc2_hsotg *, no you cannot escape the structs, i'm sorry 😭
• host — the host mode flag, it's a bool, iconic of it honestly

💖 DESCRIPTION 💖

so like, why would you even force a mode? great question, bestie, there are exactly two cases and i'm gonna tell you about both 🫶

1. if the dr_mode is set to either HOST or PERIPHERAL, we force the controller to stay in that particular mode regardless of ID pin changes. we do this once during probe. one and done, periodt ✨
2. during probe we want to read reset values of the hw configuration registers that are only available in either host or device mode. we may need to force the mode if the current mode does not allow us to access the register in the mode that we want. like, the register isn't gonna open the door for you unless you're in the right mode, so 😤

in either case it only makes sense to force the mode if the controller hardware is OTG capable. no OTG, no forcing, that's the rule 💀

checks are done in this function to determine whether doing a force would be valid or not. so it's not just out here forcing things all willy-nilly, it does a vibe check first 🌈

if a force is done, it requires a IDDIG debounce filter delay if the filter is configured and enabled. we poll the current mode of the controller to account for this delay. patience is a virtue, bestie 🧚

⭐ SEE ALSO ⭐

kernel file ./drivers/usb/dwc2/core.c and its whole friend group, no cap:

• dwc2_backup_global_registers(9)
• dwc2_restore_global_registers(9)
• dwc2_exit_partial_power_down(9)
• dwc2_enter_partial_power_down(9)
• dwc2_restore_essential_regs(9)
• dwc2_hib_restore_common(9)
• dwc2_wait_for_mode(9)
• dwc2_iddig_filter_enabled(9)
• dwc2_clear_force_mode(9)
• dwc2_dump_host_registers(9)
• dwc2_dump_global_registers(9)
• dwc2_flush_tx_fifo(9)
• dwc2_flush_rx_fifo(9)
• dwc2_enable_global_interrupts(9)
• dwc2_disable_global_interrupts(9)
• dwc2_hsotg_wait_bit_set(9)
• dwc2_hsotg_wait_bit_clear(9)

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okay and like, the cute little sign-off at the bottom? sourced from ./drivers/usb/dwc2, dated October 2026, and the page itself is dwc2_force_mode(9). mwah 💋 go force some modes, bestie, you got this 💜