drm/panel: Changes for v3.15-rc1

Add support for a couple more simple panels. A few cleanups to the
simple panel driver are also included (gpiod interface conversion,
removal of redundant call to regulator_disable()).

* tag 'drm/panel/for-3.15-rc1' of git://anongit.freedesktop.org/tegra/linux:
  drm/panel: add support for LG LD070WX3-SL01 panel
  drm/panel: add support for LG LH500WX1-SD03 panel
  drm/panel: simple: Allow DSI panels to provide mode flags
  drm/panel: simple: Allow GPIO accesses to sleep
  drm/panel: remove redundant regulator_disable()
  drm/panel: use gpiod interface for enable GPIO
  drm/panel: Add LG 12.9" LCD panel
  MAINTAINERS: Add entry for DRM panel drivers

Conflicts:
	MAINTAINERS

The patch adds MIPI-DSI based S6E8AA0 AMOLED LCD panel driver.
Driver uses mipi_dsi bus to communicate with panel and exposes drm_panel
interface.

v2
- added bus error handling,
- set maxmimum DSI packet size on init,
- removed unsupported brightness drm_panel callbacks,
- minor improvements

v3
- switched to gpiod framework,
- minor fixes in error handling

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

The patch adds LD9040 parallel RGB panel driver with SPI control interface.
The driver uses drm_panel framework.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

This panel is used by Tegra Note 7 and supported by the simple-panel
driver.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

This panel is used by the NVIDIA SHIELD and supported by the
simple-panel driver.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

In order to differentiate between the different video modes (burst vs.
non-burst, sync pulses vs. sync events) supported by peripherals, pass
the flags that specify this mode in the panel description to the DSI
peripheral device when probed.

Signed-off-by: Thierry Reding <treding@nvidia.com>

The enable GPIO for panels may be provided by GPIO expanders on slow
busses (such as I2C), and therefore toggling the GPIO may sleep. Since
these accesses don't happen in interrupt context, use the *_cansleep()
variants of the GPIO API.

Signed-off-by: Thierry Reding <treding@nvidia.com>

regulator_disable() is already performed by panel_simple_disable(),
which is called by panel_simple_remove().

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Use the new GPIO descriptor interface to handle the panel's enable GPIO.
This considerably simplifies the code.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
[treding@nvidia.com: rework to improve readability]
Signed-off-by: Thierry Reding <treding@nvidia.com>

The LP129QE LCD has an LED backlight and a display resolution of
2560x1700 pixels.

Signed-off-by: Thierry Reding <treding@nvidia.com>