Messages in this thread | | | From | Andrzej Pietrasiewicz <> | Subject | [PATCH v2 0/2] Associate ddc adapters with connectors | Date | Tue, 25 Jun 2019 12:24:39 +0200 |
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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 second patch 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
Andrzej Pietrasiewicz (2): drm: Include ddc adapter pointer in struct drm_connector drm/exynos: Provide ddc symlink in connector's sysfs
drivers/gpu/drm/drm_sysfs.c | 7 +++++++ drivers/gpu/drm/exynos/exynos_hdmi.c | 11 +++++------ include/drm/drm_connector.h | 11 +++++++++++ 3 files changed, 23 insertions(+), 6 deletions(-)
-- 2.17.1
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