It is difficult for a user to know which of the i2c adapters is for which drm connector. This series addresses this problem.
The idea is to have a symbolic link in connector's sysfs directory, e.g.:
ls -l /sys/class/drm/card0-HDMI-A-1/ddc lrwxrwxrwx 1 root root 0 Jun 24 10:42 /sys/class/drm/card0-HDMI-A-1/ddc \ -> ../../../../soc/13880000.i2c/i2c-2
The user then knows that their card0-HDMI-A-1 uses i2c-2 and can e.g. run ddcutil:
ddcutil -b 2 getvcp 0x10 VCP code 0x10 (Brightness ): current value = 90, max value = 100
The first patch in the series adds struct i2c_adapter pointer to struct drm_connector. If the field is used by a particular driver, then an appropriate symbolic link is created by the generic code, which is also added by this patch.
The next 22 patches is an example of how to convert a driver to this new scheme.
v1..v2:
- used fixed name "ddc" for the symbolic link in order to make it easy for userspace to find the i2c adapter
v2..v3:
- converted as many drivers as possible.
v3..v4:
- added Reviewed-by for patch 01/23 - moved "ddc" field assignment to before drm_connector_init() is called in msm, vc4, sti, mgag200, ast, amdgpu, radeon - simplified the code in amdgpu and radeon at the expense of some lines exceeding 80 characters as per Alex Deucher's suggestion - added i915
TODO: nouveau, gma500, omapdrm, panel-simple - if applicable. Other drivers are either already converted or don't mention neither "ddc" nor "i2c_adapter".
Andrzej Pietrasiewicz (23): drm: Include ddc adapter pointer in struct drm_connector drm/exynos: Provide ddc symlink in connector's sysfs drm: rockchip: Provide ddc symlink in rk3066_hdmi sysfs directory drm: rockchip: Provide ddc symlink in inno_hdmi sysfs directory drm/msm/hdmi: Provide ddc symlink in hdmi connector sysfs directory drm/sun4i: hdmi: Provide ddc symlink in sun4i hdmi connector sysfs directory drm/mediatek: Provide ddc symlink in hdmi connector sysfs directory drm/tegra: Provide ddc symlink in output connector sysfs directory drm/imx: imx-ldb: Provide ddc symlink in connector's sysfs drm/imx: imx-tve: Provide ddc symlink in connector's sysfs drm/vc4: Provide ddc symlink in connector sysfs directory drm: zte: Provide ddc symlink in hdmi connector sysfs directory drm: zte: Provide ddc symlink in vga connector sysfs directory drm/tilcdc: Provide ddc symlink in connector sysfs directory drm: sti: Provide ddc symlink in hdmi connector sysfs directory drm/mgag200: Provide ddc symlink in connector sysfs directory drm/ast: Provide ddc symlink in connector sysfs directory drm/bridge: dumb-vga-dac: Provide ddc symlink in connector sysfs directory drm/bridge: dw-hdmi: Provide ddc symlink in connector sysfs directory drm/bridge: ti-tfp410: Provide ddc symlink in connector sysfs directory drm/amdgpu: Provide ddc symlink in connector sysfs directory drm/radeon: Provide ddc symlink in connector sysfs directory drm/i915: Provide ddc symlink in hdmi connector sysfs directory
.../gpu/drm/amd/amdgpu/amdgpu_connectors.c | 56 ++++++++----- drivers/gpu/drm/ast/ast_mode.c | 9 ++- drivers/gpu/drm/bridge/dumb-vga-dac.c | 19 +++-- drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 40 +++++----- drivers/gpu/drm/bridge/ti-tfp410.c | 19 +++-- drivers/gpu/drm/drm_sysfs.c | 7 ++ drivers/gpu/drm/exynos/exynos_hdmi.c | 11 ++- drivers/gpu/drm/i915/display/intel_hdmi.c | 5 +- drivers/gpu/drm/imx/imx-ldb.c | 13 ++- drivers/gpu/drm/imx/imx-tve.c | 8 +- drivers/gpu/drm/mediatek/mtk_hdmi.c | 9 +-- drivers/gpu/drm/mgag200/mgag200_mode.c | 9 ++- drivers/gpu/drm/msm/hdmi/hdmi_connector.c | 1 + drivers/gpu/drm/radeon/radeon_connectors.c | 80 ++++++++++++------- drivers/gpu/drm/rockchip/inno_hdmi.c | 17 ++-- drivers/gpu/drm/rockchip/rk3066_hdmi.c | 17 ++-- drivers/gpu/drm/sti/sti_hdmi.c | 1 + drivers/gpu/drm/sun4i/sun4i_hdmi.h | 1 - drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c | 14 ++-- drivers/gpu/drm/tegra/drm.h | 1 - drivers/gpu/drm/tegra/output.c | 12 +-- drivers/gpu/drm/tegra/sor.c | 6 +- drivers/gpu/drm/tilcdc/tilcdc_tfp410.c | 1 + drivers/gpu/drm/vc4/vc4_hdmi.c | 21 ++--- drivers/gpu/drm/zte/zx_hdmi.c | 25 +++--- drivers/gpu/drm/zte/zx_vga.c | 25 +++--- include/drm/drm_connector.h | 11 +++ 27 files changed, 240 insertions(+), 198 deletions(-)