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

[jg1.han@samsung.com: modified the commit message]
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NJingoo Han <jg1.han@samsung.com>

Fix a bug where we check !dp->irq instead of the correct check for
-ENXIO.
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Reviewed-by: NOlof Johansson <olofj@chromium.org>
Signed-off-by: NJingoo Han <jg1.han@samsung.com>

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: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NJingoo Han <jg1.han@samsung.com>

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: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NJingoo Han <jg1.han@samsung.com>

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: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NJingoo Han <jg1.han@samsung.com>

Add return code checks to the DPCD transactions in the SW link training
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NJingoo Han <jg1.han@samsung.com>

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: NAjay Kumar <ajaykumar.rs@samsung.com>
Signed-off-by: NJingoo Han <jg1.han@samsung.com>

Convert clk_enable/clk_disable to clk_prepare_enable/clk_disable_unprepare
calls as required by common clock framework.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

To check channel equalization, the value of LANE_ALIGN_STATUS_UPDATED is
necessary in exynos_dp_channel_eq_ok(). Also, link_align includes this value.
However, link_status does not include this value, so it makes the problem
that channel equalization is failed during link training.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

SW reset sets DP TX to initial value, so configurations for analog parameter
and interrupt are not set properly. Therefore, exynos_dp_init_analog_param()
and exynos_dp_init_interrupt() should be moved to after sw reset is called,
in order to set these values properly.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

The devm_clk_get function allocates memory that is released when a driver
detaches. This patch uses this function for data that is allocated in the probe
function of a platform device and is only freed in the remove function.

Additionally, this patch removes a null check after platform_get_resource that
is redundant with the one done by devm_request_and_ioremap.
Signed-off-by: NDamien Cassou <damien.cassou@lifl.fr>
Acked-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

This patch adds adjustement for voltage swing and pre-emphasis during
Link Training procedure. According to the DP specification, unless all
the LANEx_CR_DONE bits are set, the transmitter must read
the ADJUST_REQUEST_LANEx_x, increase the voltage swing according to
the request, and update the TRAINING_LANEx_SET bytes to match the new
voltage swing setting.

Refer to the DP specification v1.1a, Section 3.5.1.3 Link Training.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

This patch replaces udelay and mdelay with usleep_range to remove
the busy loop waiting.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

The only INTERLANE_ALIGN_DONE bit should be checked for channel equalization
during Link Training. Previously, the other bits such as LINK_STATUS_UPDATED
were checked, and channel equalization procedure was repeated unnecessarily.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

Wrong DPCD addresses were used for clock recovery during Link Training.
The training pattern should be set by TRAINING_PATTERN_SET (0x102), while
voltage swing and pre-emphasis should be set by TRAINING_LANE0_SET (0x103).
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

This patch fixes build warning due to uninitialized value dereference.

drivers/video/exynos/exynos_dp_core.c: In function 'exynos_dp_set_link_train':
drivers/video/exynos/exynos_dp_core.c:529:18: warning: 'reg' may be used uninitialized in this function [-Wuninitialized]
drivers/video/exynos/exynos_dp_core.c:395:6: note: 'reg' was declared here
Signed-off-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

This patch reduces delay time when configuring video setting,
which is helpful to reduce wakeup time during resume.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

The sw reset should be called prioir to enabling sw defined function,
according to datasheet.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

The devm_ functions allocate memory that is released when a driver
detaches. This makes the code smaller and a bit simpler.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

Remove unnecessary headers from the file.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

The char pointer for adjust_request variable is replaced with char array
to fix possible null pointer dereference when clock recovery is failed.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

Samsung EXYNOS SoC such Exynos5 has DP controller and embedded DP
panel can be used. This patch supports DP driver based on Samsung
EXYNOS SoC chip.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>