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| author | Andrzej Pietrasiewicz <andrzej.p@collabora.com> | 2019-07-26 19:22:55 +0200 |
|---|---|---|
| committer | Neil Armstrong <narmstrong@baylibre.com> | 2019-07-31 16:26:33 +0200 |
| commit | e1a29c6c59553d80a8e17d63494c65a13fb8e241 (patch) | |
| tree | abe2bf68a25b1c6894b75ce39764a34d24de5491 | |
| parent | 77b8cabf3d529725e59b71671a562556f6c84446 (diff) | |
| download | lwn-e1a29c6c59553d80a8e17d63494c65a13fb8e241.tar.gz lwn-e1a29c6c59553d80a8e17d63494c65a13fb8e241.zip | |
drm: Add ddc link in sysfs created by drm_connector
Add generic code which creates symbolic links in sysfs, pointing to ddc
interface used by a particular video output. For example:
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
This makes it easy for user to associate a display with its ddc adapter
and use e.g. ddcutil to control the chosen monitor.
This patch adds an i2c_adapter pointer to struct drm_connector. Particular
drivers can then use it instead of using their own private instance. If a
connector contains a ddc, then create a symbolic link in sysfs.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/d470def6cd661b777faeee67b5838a4623c4010e.1564161140.git.andrzej.p@collabora.com
| -rw-r--r-- | drivers/gpu/drm/drm_sysfs.c | 8 | ||||
| -rw-r--r-- | include/drm/drm_connector.h | 11 |
2 files changed, 19 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c index ad10810bc972..e962a9d45f7e 100644 --- a/drivers/gpu/drm/drm_sysfs.c +++ b/drivers/gpu/drm/drm_sysfs.c @@ -14,6 +14,7 @@ #include <linux/err.h> #include <linux/export.h> #include <linux/gfp.h> +#include <linux/i2c.h> #include <linux/kdev_t.h> #include <linux/slab.h> @@ -294,6 +295,9 @@ int drm_sysfs_connector_add(struct drm_connector *connector) /* Let userspace know we have a new connector */ drm_sysfs_hotplug_event(dev); + if (connector->ddc) + return sysfs_create_link(&connector->kdev->kobj, + &connector->ddc->dev.kobj, "ddc"); return 0; } @@ -301,6 +305,10 @@ void drm_sysfs_connector_remove(struct drm_connector *connector) { if (!connector->kdev) return; + + if (connector->ddc) + sysfs_remove_link(&connector->kdev->kobj, "ddc"); + DRM_DEBUG("removing \"%s\" from sysfs\n", connector->name); diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h index 4c30d751487a..33a6fff85fdb 100644 --- a/include/drm/drm_connector.h +++ b/include/drm/drm_connector.h @@ -41,6 +41,7 @@ struct drm_property; struct drm_property_blob; struct drm_printer; struct edid; +struct i2c_adapter; enum drm_connector_force { DRM_FORCE_UNSPECIFIED, @@ -1311,6 +1312,16 @@ struct drm_connector { * [0]: progressive, [1]: interlaced */ int audio_latency[2]; + + /** + * @ddc: associated ddc adapter. + * A connector usually has its associated ddc adapter. If a driver uses + * this field, then an appropriate symbolic link is created in connector + * sysfs directory to make it easy for the user to tell which i2c + * adapter is for a particular display. + */ + struct i2c_adapter *ddc; + /** * @null_edid_counter: track sinks that give us all zeros for the EDID. * Needed to workaround some HW bugs where we get all 0s |