linux-toradex.git/drivers/gpu/drm/tegra/dsi.c, branch v4.9.2

drm/tegra: dsi: Enhance runtime power management

2016-08-24T13:58:57+00:00

The MIPI DSI output on Tegra SoCs requires some external logic to
calibrate the MIPI pads before a video signal can be transmitted. This
MIPI calibration logic requires to be powered on while the MIPI pads are
being used, which is currently done as part of the DSI driver's probe
implementation.

This is suboptimal because it will leave the MIPI calibration logic
powered up even if the DSI output is never used.

On Tegra114 and earlier this behaviour also causes the driver to hang
while trying to power up the MIPI calibration logic because the power
partition that contains the MIPI calibration logic will be powered on
by the display controller at output pipeline configuration time. Thus
the power up sequence for the MIPI calibration logic happens before
it's power partition is guaranteed to be enabled.

Fix this by splitting up the API into a request/free pair of functions
that manage the runtime dependency between the DSI and the calibration
modules (no registers are accessed) and a set of enable, calibrate and
disable functions that program the MIPI calibration logic at points in
time where the power partition is really enabled.

While at it, make sure that the runtime power management also works in
ganged mode, which is currently also broken.

Reported-by: Jonathan Hunter 
Tested-by: Jonathan Hunter 
Signed-off-by: Thierry Reding

Merge tag 'drm/tegra/for-4.8-rc1' of git://anongit.freedesktop.org/tegra/linux into drm-next

2016-07-16T01:23:50+00:00

drm/tegra: Changes for v4.8-rc1

This set of changes contains a bunch of cleanups to the host1x driver as
well as the addition of a pin controller for DPAUX, which is required by
boards to configure the DPAUX pads in AUX mode (for DisplayPort) or I2C
mode (for HDMI and DDC).

Included is also a bit of rework of the SOR driver in preparation to add
DisplayPort support as well as some refactoring and cleanup.

Finally, all output drivers are converted to runtime PM, which greatly
simplifies the handling of clocks and resets.

* tag 'drm/tegra/for-4.8-rc1' of git://anongit.freedesktop.org/tegra/linux: (35 commits)
  drm/tegra: sor: Reject HDMI 2.0 modes
  drm/tegra: sor: Prepare for generic PM domain support
  drm/tegra: dsi: Prepare for generic PM domain support
  drm/tegra: sor: Make XBAR configurable per SoC
  drm/tegra: sor: Use sor1_src clock to set parent for HDMI
  dt-bindings: display: tegra: Add source clock for SOR
  drm/tegra: sor: Implement sor1_brick clock
  drm/tegra: sor: Implement runtime PM
  drm/tegra: hdmi: Implement runtime PM
  drm/tegra: dsi: Implement runtime PM
  drm/tegra: dc: Implement runtime PM
  drm/tegra: hdmi: Enable audio over HDMI
  drm/tegra: sor: Do not support deep color modes
  drm/tegra: sor: Extract tegra_sor_mode_set()
  drm/tegra: sor: Split out tegra_sor_apply_config()
  drm/tegra: sor: Rename tegra_sor_calc_config()
  drm/tegra: sor: Factor out tegra_sor_set_parent_clock()
  drm/tegra: dpaux: Add pinctrl support
  dt-bindings: Add bindings for Tegra DPAUX pinctrl driver
  drm/tegra: Prepare DPAUX for supporting generic PM domains
  ...

drm/tegra: dsi: Prepare for generic PM domain support

2016-07-14T12:57:02+00:00

The DSI driver for Tegra requires the SOR power partition to be enabled.
Now that Tegra supports the generic PM domain framework we manage the
SOR power partition via this framework. However, the sequence for
gating/ungating the SOR power partition requires that the DSI reset is
asserted/de-asserted at the time the SOR power partition is
gated/ungated, respectively. Now that the reset control core assumes
that resets are exclusive, the Tegra generic PM domain code and the DSI
driver cannot request the same reset unless we mark the reset as shared.
Sharing resets will not work in this case because we cannot guarantee
that the reset will be asserted/de-asserted at the appropriate time.
Therefore, given that the Tegra generic PM domain code will handle the
resets, do not request the reset in the DSI driver if the DSI device has
a PM domain associated.

Signed-off-by: Jon Hunter 
Signed-off-by: Thierry Reding

drm/tegra: dsi: Implement runtime PM

2016-07-04T09:37:00+00:00

Use runtime PM to clock-(un)gate, (de)assert reset and control power to
the DSI controller. This ties in nicely with atomic DPMS in that a
runtime PM reference is taken before a pipe is enabled and dropped after
it has been shut down.

Signed-off-by: Thierry Reding

drm: tegra: Rely on the default ->best_encoder() behavior

2016-06-10T15:24:48+00:00

All outputs have a 1:1 relationship between connectors and encoders
and the driver is relying on the atomic helpers: we can drop the custom
->best_encoder() implementation and let the core call
drm_atomic_helper_best_encoder() for us.

Signed-off-by: Boris Brezillon 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/1465300095-16971-14-git-send-email-boris.brezillon@free-electrons.com

drm/tegra: Fix crash caused by reference count imbalance

2016-05-18T16:03:33+00:00

Commit d2307dea14a4 ("drm/atomic: use connector references (v3)") added
reference counting for DRM connectors and this caused a crash when
exercising system suspend on Tegra114 Dalmore.

The Tegra DSI driver implements a Tegra specific function,
tegra_dsi_connector_duplicate_state(), to duplicate the connector state
and destroys the state using the generic helper function,
drm_atomic_helper_connector_destroy_state(). Following commit
d2307dea14a4 ("drm/atomic: use connector references (v3)") there is
now an imbalance in the connector reference count because the Tegra
function to duplicate state does not take a reference when duplicating
the state information. However, the generic helper function to destroy
the state information assumes a reference has been taken and during
system suspend, when the connector state is destroyed, this leads to a
crash because we attempt to put the reference for an object that has
already been freed.

Fix this by calling __drm_atomic_helper_connector_duplicate_state() from
tegra_dsi_connector_duplicate_state() to ensure that we take a reference
on a connector if crtc is set. Note that this will also copy the
connector state a 2nd time, but this should be harmless.

By fixing tegra_dsi_connector_duplicate_state() to take a reference,
although a crash was no longer seen, it was then observed that after
each system suspend-resume cycle, the reference would be one greater
than before the suspend-resume cycle. Following commit d2307dea14a4
("drm/atomic: use connector references (v3)"), it was found that we
also need to put the reference when calling the function
tegra_dsi_connector_reset() before freeing the state. Fix this by
updating tegra_dsi_connector_reset() to call the function
__drm_atomic_helper_connector_destroy_state() in order to put the
reference for the connector.

Fixes: d2307dea14a4 ("drm/atomic: use connector references (v3)")

Signed-off-by: Jon Hunter 
Reviewed-by: Daniel Vetter 
Acked-by: Thierry Reding 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/1463585856-16606-1-git-send-email-jonathanh@nvidia.com

drm/tegra: Use __drm_atomic_helper_reset_connector for subclassing connector state, v2.

2016-01-05T08:43:26+00:00

Changes since v1:
- Do not reset if state allocation fails.

Signed-off-by: Maarten Lankhorst 
Acked-by: Thierry Reding  #irc
Link: http://patchwork.freedesktop.org/patch/msgid/1451908400-25147-3-git-send-email-maarten.lankhorst@linux.intel.com
Signed-off-by: Daniel Vetter

drm: Pass 'name' to drm_encoder_init()

2015-12-11T08:13:20+00:00

Done with coccinelle for the most part. However, it thinks '...' is
part of the semantic patch, so I put an 'int DOTDOTDOT' placeholder
in its place and got rid of it with sed afterwards.

@@
identifier dev, encoder, funcs;
@@
 int drm_encoder_init(struct drm_device *dev,
                      struct drm_encoder *encoder,
                      const struct drm_encoder_funcs *funcs,
                      int encoder_type
+                     ,const char *name, int DOTDOTDOT
                      )
{ ... }

@@
identifier dev, encoder, funcs;
@@
 int drm_encoder_init(struct drm_device *dev,
                      struct drm_encoder *encoder,
                      const struct drm_encoder_funcs *funcs,
                      int encoder_type
+                     ,const char *name, int DOTDOTDOT
                      );

@@
expression E1, E2, E3, E4;
@@
 drm_encoder_init(E1, E2, E3, E4
+                 ,NULL
                  )

v2: Add ', or NULL...' to @name kernel doc (Jani)
    Annotate the function with __printf() attribute (Jani)

Signed-off-by: Ville Syrjälä 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/1449670818-2966-1-git-send-email-ville.syrjala@linux.intel.com

drm/tegra: dsi: Restore DPMS

2015-08-13T11:49:23+00:00

In order to restore DPMS with atomic mode-setting, move all code from
the ->mode_set() callback into ->enable(). At the same time, rename the
->prepare() callback to ->disable() to use the names preferred by atomic
mode-setting. This simplifies the calling sequence and will allow DPMS
to use runtime PM in subsequent patches.

Signed-off-by: Thierry Reding

drm/tegra: dsi: Add Tegra210 support

2015-08-13T11:47:45+00:00

The DSI host controller hasn't changed from Tegra132 to Tegra210, but
different characterization parameters may be required.

Signed-off-by: Thierry Reding