[PATCH v6 00/24] Associate ddc adapters with connectors

[Andrzej Pietrasiewicz]

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.

Patch 2 adds a new variant of drm_connector_init(), see the changelog
below.

Patches 3..24 are examples 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

v4..v5:

- changed "include <linux/i2c.h>" to "struct i2c_adapter;"
in drm_connector.h, consequently, added "include <linux/i2c.h>"
in drm_sysfs.c.
- added "drm_connector_init_with_ddc()" variant to ensure that the ddc
field of drm_connector is preserved accross its invocation
- accordingly changed invocations of drm_connector_init() in the
touched drivers to use the new variant

v5..v6:

- improved subject line of patch 1
- added kernel-doc for drm_connector_init_with_ddc()
- improved kernel-doc for the ddc field of struct drm_connector
- added Reviewed-by in patches 17 and 18
- added Acked-by in patch 2
- made the ownership of ddc i2c_adapter explicit in all patches,
this made the affected patches much simpler

@Benjamin
@Shawn

There were your Acked-by or Reviewed-by for some patches in v4, but now
that the patches use the newly added function I'm not sure I can still
include those tags without you actually confirming. Can I? Or can you
please re-review? 

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 (24):
  drm: Add ddc link in sysfs created by drm_connector
  drm: Add drm_connector_init() variant with ddc
  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    |  96 ++++++++----
 drivers/gpu/drm/ast/ast_mode.c                |  13 +-
 drivers/gpu/drm/bridge/dumb-vga-dac.c         |   6 +-
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c     |   6 +-
 drivers/gpu/drm/bridge/ti-tfp410.c            |   6 +-
 drivers/gpu/drm/drm_connector.c               |  35 +++++
 drivers/gpu/drm/drm_sysfs.c                   |   8 +
 drivers/gpu/drm/exynos/exynos_hdmi.c          |   6 +-
 drivers/gpu/drm/i915/display/intel_hdmi.c     |  12 +-
 drivers/gpu/drm/imx/imx-ldb.c                 |   7 +-
 drivers/gpu/drm/imx/imx-tve.c                 |   6 +-
 drivers/gpu/drm/mediatek/mtk_hdmi.c           |   7 +-
 drivers/gpu/drm/mgag200/mgag200_mode.c        |  13 +-
 drivers/gpu/drm/msm/hdmi/hdmi_connector.c     |   6 +-
 drivers/gpu/drm/radeon/radeon_connectors.c    | 142 +++++++++++++-----
 drivers/gpu/drm/rockchip/inno_hdmi.c          |   6 +-
 drivers/gpu/drm/rockchip/rk3066_hdmi.c        |   7 +-
 drivers/gpu/drm/sti/sti_hdmi.c                |   6 +-
 drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c        |   7 +-
 drivers/gpu/drm/tegra/hdmi.c                  |   7 +-
 drivers/gpu/drm/tegra/sor.c                   |   7 +-
 drivers/gpu/drm/tilcdc/tilcdc_tfp410.c        |   6 +-
 drivers/gpu/drm/vc4/vc4_hdmi.c                |  12 +-
 drivers/gpu/drm/zte/zx_hdmi.c                 |   6 +-
 drivers/gpu/drm/zte/zx_vga.c                  |   6 +-
 include/drm/drm_connector.h                   |  18 +++
 26 files changed, 336 insertions(+), 121 deletions(-)

-- 
2.17.1