ENUM DRM_BUS_FLAGS(9)

✨ enum drm_bus_flags 💅

Okay bestie, welcome to the enum drm_bus_flags(9) glow-up — it's a Kernel API Manual moment, and this one is literally the vibe check for bus_flags info for &drm_display_info 🦋. Yes, that's the whole NAME situation, we're not wasting a single word of it.

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🌸 SYNOPSIS 🌸

enum drm_bus_flags {
    DRM_BUS_FLAG_DE_LOW ,
    DRM_BUS_FLAG_DE_HIGH ,
    DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE ,
    DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE ,
    DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE ,
    DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE ,
    DRM_BUS_FLAG_DATA_MSB_TO_LSB ,
    DRM_BUS_FLAG_DATA_LSB_TO_MSB ,
    DRM_BUS_FLAG_SYNC_DRIVE_POSEDGE ,
    DRM_BUS_FLAG_SYNC_DRIVE_NEGEDGE ,
    DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE ,
    DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE ,
    DRM_BUS_FLAG_SHARP_SIGNALS

};

No cap, that's every single one of them, reproduced exactly — we do not edit the king 👑.

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🎀 Constants 🎀

• DRM_BUS_FLAG_DE_LOW — Data Enable? Active low bestie, that's the whole tea 🍓
• DRM_BUS_FLAG_DE_HIGH — Data Enable, but make it active high ✨
• DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE — the data gets driven on the rising edge of the pixel clock 🌅
• DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE — data driven on the falling edge of the pixel clock 🌙
• DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE — data sampled on the rising edge of the pixel clock 🌅
• DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE — data sampled on the falling edge of the pixel clock 🌙
• DRM_BUS_FLAG_DATA_MSB_TO_LSB — data going out MSB to LSB on the bus, in that order, respectfully 💅
• DRM_BUS_FLAG_DATA_LSB_TO_MSB — data going out LSB to MSB on the bus, the other direction, also respectfully 💅
• DRM_BUS_FLAG_SYNC_DRIVE_POSEDGE — sync signals driven on the rising edge of the pixel clock 🔥
• DRM_BUS_FLAG_SYNC_DRIVE_NEGEDGE — sync signals driven on the falling edge of the pixel clock 💀
• DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE — sync signals sampled on the rising edge of the pixel clock ⭐
• DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE — sync signals sampled on the falling edge of the pixel clock 🌈
• DRM_BUS_FLAG_SHARP_SIGNALS — set this if the Sharp-specific signals (SPL, CLS, PS, REV) must be used 👑 (yes, those four, exactly those four, don't come for me)

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💜 Description 💜

So this enum is your one-stop shop: it defines signal polarities and clock edge information for signals on a bus, all as bitmask flags 🫶.

The clock edge info is carried by two sets of symbols — DRM_BUS_FLAGS_*_DRIVE_ and DRM_BUS_FLAGS_*_SAMPLE_ 🦋. Okay so which one do you use? Depends on your main character energy:

• Describing a bus from the transmitter's point of view? Use the DRIVE_ flags 📤
• Describing it from the receiver's point of view? Use the SAMPLE_ flags 📥

And here's the iconic part: the DRIVE_ and SAMPLE_ flags alias each other, with the SAMPLE_POSEDGE and SAMPLE_NEGEDGE flags being equal to DRIVE_NEGEDGE and DRIVE_POSEDGE respectively 😭💖. Which honestly simplifies code a lot, because signals are usually sampled on the opposite edge of the driving edge — it's giving symmetry, it's giving efficiency.

Real talk though: transmitters and receivers may however need to take other signal timings into account to convert between driving and sample edges. Don't assume the alias does all your homework for you 🙈.

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🌟 SEE ALSO 🌟

Kernel file ./include/drm/drm_connector.h — and like, the whole extended friend group:

enum drm_connector_status(9), enum drm_connector_registration_state(9), enum drm_connector_tv_mode(9), struct drm_scrambling(9), struct drm_hdmi_dsc_cap(9), struct drm_hdmi_info(9), enum drm_link_status(9), enum drm_panel_orientation(9), enum drm_hdmi_broadcast_rgb(9), struct drm_monitor_range_info(9), struct drm_luminance_range_info(9), enum drm_privacy_screen_status(9), enum drm_colorspace(9), enum drm_output_color_format(9), enum drm_connector_color_format(9), struct drm_amd_vsdb_info(9), struct drm_display_info(9), struct drm_connector_tv_margins(9), struct drm_tv_connector_state(9), struct drm_connector_hdmi_infoframe(9), struct drm_connector_state(9), struct drm_connector_cec_funcs(9), struct drm_connector_infoframe_funcs(9), struct drm_connector_hdmi_funcs(9), struct drm_connector_funcs(9), struct drm_cmdline_mode(9), struct drm_connector_hdmi_audio(9), struct drm_connector_cec(9), struct drm_connector(9), drm_connector_lookup(9), drm_connector_get(9), drm_connector_put(9), drm_connector_is_unregistered(9), struct drm_tile_group(9), struct drm_connector_list_iter(9), drm_for_each_connector_iter(9), drm_connector_for_each_possible_encoder(9)

Every single one, no skips, no cap 🧚💜.

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✨ that's the whole page bestie, go read your kernel headers, they're literally iconic ✨

And a cute lil sign-off for the credits: this one lives in ./include/drm, stamped October 2026, and it's the enum drm_bus_flags(9) Kernel API Manual page — mwah 💋🌸