video: exynos_dp: Add device tree support to DP driver

This patch enables device tree based discovery support for DP driver.
The driver is modified to handle platform data in both the cases:
with DT and non-DT.

Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
video: exynos_dp: device tree documentation

Add documentation for the DT bindings in exynos display port driver.

Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
video: exynos_dp: Check DPCD return codes

Add return code checks to the DPCD transactions in the SW link training

Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
video: exynos_dp: Clean up SW link training

Clean up some of the SW training code to make it more clear and reduce
duplicate code.

[jg1.han@samsung.com: used exynos_dp_write_bytes_to_dpcd()]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
video: exynos_dp: Get pll lock before pattern set

According to the exynos datasheet (Figure 49-10), we should wait for PLL
lock before programming the training pattern when doing software eDP
link training.

Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
video: exynos_dp: Improve EDID error handling

EDID error handling has 2 problems:
 - It doesn't fail as early as it can
 - The retry counts for i2c and aux transactions are huge

This patch fails if the initial i2c transaction fails, and reduces the
aux and i2c retry counts down to 3.

[jg1.han@samsung.com: reduced the retry count of exynos_dp_read_byte_from_dpcd()]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
video: exynos_dp: Fix bug when checking dp->irq

Fix a bug where we check !dp->irq instead of the correct check for
-ENXIO.

Signed-off-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Olof Johansson <olofj@chromium.org>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
video: exynos_dp: Remove sink control to D0

According to DP spec, it is not required in the Link Training
procedure.

[jg1.han@samsung.com: modified the commit message]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
video: exynos_dp: Move hotplug into a workqueue

Move the hotplug related code from probe and resume into a workqueue.
This allows us to initialize the DP driver (and resume it) when there
is no monitor connected.

Signed-off-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Olof Johansson <olofj@chromium.org>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
video: exynos_dp: Enable hotplug interrupts

Enable hotplug interrupts and move the hotplug scheduling into the
interrupt handler. This allows us to introduce a screen at any time
while we're running.

[jg1.han@samsung.com: moved the bit masking of hotplug interrupts]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Olof Johansson <olofj@chromium.org>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
video: exynos_dp: Reset and initialize DP before requesting irq

If DP is not reset properly before kernel bootup(in bootloader code),
there can be few pending interrupts, and sometimes they invoke
DP irq handler as soon as the irq handler is registered in DP probe.
So, we make the DP driver more robust by resetting and
initializing DP at the earliest and then registering the irq handler.

Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
video: exynos_dp: Fix incorrect setting for INT_CTL

INT_CTL register contains bits INT_POL0 and INT_POL1, and not INT_POL.
This patch fixes the wrong register setting for INT_CTL.

Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
video: exynos_dp: remove redundant parameters

This patch cleans up few redundant parameters keeping
the same functionality intact.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>