Clean up LCDC functional clock rate setting code.

The LCDC functional clock is set by two functions: mode_set_nofb() and
cpufreq_transition().

When tilcdc_crtc_mode_set_nofb() is called in atomic commit phase the
drm atomic helpers have taken all the necessary drm locks and turned
off the crtc, while tilcdc_commit() is keeping LCDC powered on. For
mode_set_nofb() just a simple clock setting function without any
locking or power management code is enough. The new tilcdc_crtc_set_clk()
is implemented for that purpose.

cpufreq_transition() on the other hand is called from outside DRM and
it needs to take the necessary locks and turn off the CRTC while
keeping the LCDC powered. The reimplemented tilcdc_crtc_update_clk()
is for that purpose and it uses the new tilcdc_crtc_set_clk() to
actually set the clock.
Signed-off-by: NJyri Sarha <jsarha@ti.com>
Reviewed-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

Write DMA base and ceiling address with a single instruction, if
available. This should make it more unlikely that LCDC would fetch the
DMA addresses in the middle of an update. Having bad combination of
addresses in dma base and ceiling (e.g base > ceiling) can cause
unpredictaple behavior in LCDC.
Signed-off-by: NJyri Sarha <jsarha@ti.com>
Reviewed-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

This got accidentally dropped in the fixed commit and is required for
the driver to properly work on the rev1 IP, such as found on the LCDK.

Fixes: 2b2080d7 ("drm/tilcdc: Get rid of complex ping-pong mechanism")
Signed-off-by: NKarl Beldan <kbeldan@baylibre.com>
Signed-off-by: NJyri Sarha <jsarha@ti.com>

The LCDC seems to expect its framebuffer ceiling address pointer to be
an inclusive bound.  The IP rev2 seems to cope with that but rev1 (as
found on the LCDK) don't.
Also note that this is what the framebuffer code does in da8xx-fb.c.

Since, as the TRM puts it, "The 2 LSBs are hardwired to 00b", the
dma_addr_t can be decremented without cast.
I tested it with a v2 (AM335x, rev  0x4F201000) and an LCDK (v1).
Signed-off-by: NKarl Beldan <kbeldan@baylibre.com>
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Change tilcdc_crtc_page_flip() to tilcdc_crtc_update_fb(). The
function is not used as a page_flip() callback anymore so it is only
confusing to call it that. The function should only be used by dummy
primary plane commit() callback.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Remove unnecessary pm_runtime_get() and *_put() calls from commit
phase callbacks. Those calls are not needed since we have the whole
commit phase between pm_runtime_get_sync() and pm_runtime_put_sync().
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Get rid of legacy dpms mechanism. This simplifies the code quite a
bit. The old start() and stop() functions become tilcdc_crtc_enable()
and *_disable(). The functions are added with all the necessary
mechanisms from the old dpms function and they are used directly as
the crtc helper enable() and disable() callbacks.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Enable and disable interrupts in crtc start() and stop(). None of the
interrupts can fire if CRTC is disabled, so it is cleaner - when
considering suspend/resume code etc. - to enable the interrupts when
CRTC is turned on and to disable them when CRTC is turned off.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Remove tilcdc_verify_fb(). The tilcdc_verify_fb() function is not
needed because the same checks are implemented in
tilcdc_plane_atomic_check().
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Remove obsolete crtc helper functions. These are not needed when
atomic modeset is used.

Note that the drm_crtc_helper_funcs mode_fixup() is still needed. The
crtc's check() callback can not do its job here.

The plane's check() callback needs to set drm_crtc_state's
->mode_changed to true if the pixel format for the framebuffer
changes. Because of this drm_mode_config_funcs atomic_check() callback
needs to call drm_atomic_helper_check_modeset() once more after it has
called drm_atomic_helper_check_planes(). If the fixing of the
adjusted_mode would be done in drm_crtc_helper_funcs atomic_check()
callback, it would get over written by the extra
drm_atomic_helper_check_modeset() call.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Set DRIVER_ATOMIC and use atomic helpers and rename commit and prepare
crtc helpers to enable and disable. This makes the final jump to mode
setting, but there is lot of obsolete code to clean up.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Add tilcdc_crtc_atomic_check(). Checks the display mode validity and
the presence of the mandatory primary plane.

The drm_crtc_helper_funcs mode_fixup() callback is left untouched and
the check function does no try to do its job on purpose, despite what
the mode_fixup() callback's documentations suggests.

The plane's check() callback needs to set drm_crtc_state's
->mode_changed to true if the pixel format for the framebuffer
changes. Because of this drm_mode_config_funcs atomic_check() callback
needs to call drm_atomic_helper_check_modeset() once more after it has
called drm_atomic_helper_check_planes(). If the fixing of the
adjusted_mode would be done in drm_crtc_helper_funcs atomic_check()
callback, it would get over written by the extra
drm_atomic_helper_check_modeset() call.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Add tilcdc_crtc_mode_set_nofb(). The mode_set_nofb() semantics do not
fit well to LCDC, because of the mandatory framebuffer. However, when
the primary plane is required in the check phase, it and the
framebuffer can be found from the atomic state struct.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Initialize dummy primary plane from crtc init.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Make tilcdc_crtc_page_flip() work if crtc is not yet on. The plane
commit sometimes comes before crtc is turned on. The new framebuffer
should be set to scanout also in that case, so that it is there when
crtc is turned on at the end of the commit phase.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Make tilcdc_crtc_page_flip() public for dummy plane implementation to use.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Add drm_crtc_vblank_on() and *_off() calls to start() and stop()
functions, to make sure any vblank waits etc. gets properly cleaned
up.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Increase time out for waiting frame done interrupt. 50ms is long
enough for the usual display modes (50 Hz or higher refresh rate), but
it may be a bit tight for some unusual mode.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Move wait queue waiting of LCDC_FRAME_DONE IRQ from tilcdc_crtc_dpms()
into stop() function. This is just a cleanup and enables independent
use of stop() function.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Reorder the IRQ function so that the write to LCDC_END_OF_INT_IND_REG
is done last. The write to LCDC_END_OF_INT_IND_REG indicates to LCDC
that the interrupt service routine has completed (see section
13.3.6.1.6 in AM335x TRM). This is needed if LCDC's ipgvmodirq module
is configured for pulse interrupts.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Move LCDC_SYNC_LOST handling inside if (ver == 2) statement.
LCDC_SYNC_LOST interrupt status bit is only defined for version 2
silicon.
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Restore old dpms state in pm_resume(). The dpms is turned off in
pm_suspend() and it should be restored to its original state in
pm_resume(). Without this patch the display is left blanked after a
suspend/resume cycle.

Fixes commit 614b3cfe ("drm/tilcdc: disable the lcd controller/dma
engine when suspend invoked")
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Remove legacy usage of drm_handle_vblank()
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1467677092-5089-6-git-send-email-gustavo@padovan.org

Replace the legacy drm_send_vblank_event() with the new helper function.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NJyri Sarha <jsarha@ti.com>
Tested-by: NJyri Sarha <jsarha@ti.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1460656118-16766-11-git-send-email-gustavo@padovan.org

Use devm_kzalloc() and devm_kcalloc() for private data allocation at
driver load time.
Signed-off-by: NJyri Sarha <jsarha@ti.com>
Reviewed-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

Initialize port device node pointer in the tilcdc crtc. Fixes "Falling
back to first CRTC" warning from tda998x driver.

The tda998x encoder driver calls drm_of_find_possible_crtcs() to
initialize possible_crtcs of struct drm_encoder. The crtc->port needs
to be initialized for drm_of_find_possible_crtcs() to work.
Signed-off-by: NJyri Sarha <jsarha@ti.com>
Reviewed-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

Disable the sync lost interrupt if it fires on every frame for 50
consecutive frames in a row. This is relatively sure sign of the sync
lost interrupt being stuck and firing on every frame even if the
display otherwise appears to work OK.
Signed-off-by: NJyri Sarha <jsarha@ti.com>
Reviewed-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

Add ratelimited prints on sync lost and FIFO underrun interrupts.
Signed-off-by: NJyri Sarha <jsarha@ti.com>
Reviewed-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

Do not update the next frame buffer close to vertical blank. This is
to avoid situation when the frame changes between writing of
LCDC_DMA_FB_BASE_ADDR_0_REG and LCDC_DMA_FB_CEILING_ADDR_0_REG.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
[Added description to the patch]
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Get rid of complex ping-pong mechanism and replace it with simpler
single buffer flipping code.

The LCDC HW appears to be designed mainly static framebuffers in
mind. There are two modes of operation, either static single buffer,
or ping pong double buffering with two static buffers switching back
and forth. Luckily the framebuffer start address is fetched only in
the beginning of the frame and changing the address after that only
takes effect after the next vertical blank. The page flipping code can
simply write the address of the new framebuffer and the page is
flipped automatically after the next vertical blank. Using the ping
pong double buffering makes the flipping code way more complex and it
does not provide any benefit, so it is better to switch to single
buffer operation.

There is still one problem in updating the framebuffer dma address on
the fly. There are two registers defining the framebuffer dma area and
things may break if the dma address is fetched in while the registers
are are being updated.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
[Added description to the patch]
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Cleanup irq handling. Clear the irq status unconditionally and
restructure the status bit conditions.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
[Added description to the patch]
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Remove broken error handling. The condition for handling the
LCDC_SYNC_LOST and LCDC_FIFO_UNDERFLOW could never be satisfied as the
LCDC_SYNC_LOST interrupt is not enabled. Also the requirement to have
both LCDC_SYNC_LOST and LCDC_FIFO_UNDERFLOW fired at once before
handling the error looks weird.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
[Added description to the patch]
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Split reset to a separate function and use usleep_range(250, 1000)
instead of msleep(1) to to keep the reset bit on long enough.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
[Added description to the patch, changed mdelay(500) to usleep_range(250, 1000)]
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Cleanup runtime PM handling. Before the patch the usage of pm_runtime
calls was inconsistent and hard to follow. After the update the
pm_runtime calls are removed from set_scanout() and called around
major operations that access the HW. After the patch the DPMS code does
not have pm_runtime_forbid/allow calls any more and
pm_runtime_irq_safe() is not set anymore.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
[Added description to the patch]
Signed-off-by: NJyri Sarha <jsarha@ti.com>

The LCD controller must be deactivated and all DMA transactions stopped
when the suspend power state is entered otherwise the PRCM causes the L3
bus to get stuck in transition state.

This commit forces the lcdc to be shut down and waits for all pending DMA
transactions to complete as part of the suspend handler for this driver.
Signed-off-by: NDarren Etheridge <detheridge@ti.com>
Tested-by: NDave Gerlach <d-gerlach@ti.com>
Signed-off-by: NJyri Sarha <jsarha@ti.com>
Reviewed-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

LCDC hardware does not support fb pitch that is different (i.e. larger)
than the screen size. The driver currently does no checks for this, and
the results of too big pitch are are flickering and lower fps.

This issue easily happens when using libdrm's modetest tool with non-32
bpp modes. As modetest always allocated 4 bytes per pixel, it implies a
bigger pitch for 16 or 24 bpp modes.

This patch adds a check to reject pitches the hardware cannot support.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NDarren Etheridge <detheridge@ti.com>
Signed-off-by: NJyri Sarha <jsarha@ti.com>

Updating the tilcdc DRM driver code to calculate the LCD controller
pixel clock more accurately. Based on a suggested implementation by
Tomi Valkeinen.

The current code does not work correctly and produces wrong results
with many requested clock rates. It also oddly uses two different
clocks, a display pll clock and a divider clock (child of display
pll), instead of just using the clock coming to the lcdc.

This patch removes the use of the display pll clock, and rewrites the
code to calculate the clock rates. The idea is simply to request a
clock rate of pixelclock*2, as the LCD controller has an internal
divider which we set to 2.
Signed-off-by: NDarren Etheridge <detheridge@ti.com>
[Rewrapped description]
Signed-off-by: NJyri Sarha <jsarha@ti.com>
Reviewed-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

Again since the drm core takes care of event unlinking/disarming this
is now just needless code.

v2: Fixup misplaced hunks.

Cc: Rob Clark <robdclark@gmail.com>
Acked-by: NDaniel Stone <daniels@collabora.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com> (v1)
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453756616-28942-13-git-send-email-daniel.vetter@ffwll.ch

Add support for an external compontised DRM encoder. The external
encoder can be connected to tilcdc trough device tree graph binding.
The binding document for tilcdc has been updated. The current
implementation supports only tda998x encoder.

To be able to filter out the unsupported video modes the tilcdc driver
needs to hijack the external connectors helper functions. The tilcdc
installes new helper functions that are otherwise identical to
orignals, but the mode_valid() call-back check the mode first localy,
before calling the original call-back. The tilcdc dirver restores the
original helper functions before it is unbound from the external
device.

I got the idea and some lines of code from Jean-Francois Moine's
"drm/tilcdc: Change the interface with the tda998x driver"-patch.
Signed-off-by: NJyri Sarha <jsarha@ti.com>
Acked-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

Force crtc dpms off before destroying the crtc instead of just
checking the dpms state. This fixes warning message and frozen picture
after tilcdc module unloading.
Signed-off-by: NJyri Sarha <jsarha@ti.com>
Acked-by: NTomi Valkeinen <tomi.valkeinen@ti.com>