Commit graph

54 commits

Author SHA1 Message Date
Lyude Paul
6cba3fe433 drm/dp: Add backpointer to drm_device in drm_dp_aux
This is something that we've wanted for a while now: the ability to
actually look up the respective drm_device for a given drm_dp_aux struct.
This will also allow us to transition over to using the drm_dbg_*() helpers
for debug message printing, as we'll finally have a drm_device to reference
for doing so.

Note that there is one limitation with this - because some DP AUX adapters
exist as platform devices which are initialized independently of their
respective DRM devices, one cannot rely on drm_dp_aux->drm_dev to always be
non-NULL until drm_dp_aux_register() has been called. We make sure to point
this out in the documentation for struct drm_dp_aux.

v3:
* Add WARN_ON_ONCE() to drm_dp_aux_register() if drm_dev isn't filled out

Signed-off-by: Lyude Paul <lyude@redhat.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210423184309.207645-4-lyude@redhat.com
Reviewed-by: Dave Airlie <airlied@redhat.com>
2021-04-27 18:43:42 -04:00
Douglas Anderson
e07e21435d drm/bridge: ti-sn65dsi86: Get rid of the useless detect() function
If we just leave the detect() function as NULL then the upper layers
assume we're always connected. There's no reason for a stub.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210416153909.v4.6.I826adf4faeb7f39f560b387f6b380e639c6986c8@changeid
2021-04-20 08:58:36 -07:00
Douglas Anderson
54fdf37206 drm/bridge: ti-sn65dsi86: Move drm_panel_unprepare() to post_disable()
We prepared the panel in pre_enable() so we should unprepare it in
post_disable() to match.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210416153909.v4.5.Ia75c9ffe2a2582393a8532d244da86f18b4c9b21@changeid
2021-04-20 08:58:24 -07:00
Douglas Anderson
4e532867e9 drm/bridge: ti-sn65dsi86: Reorder remove()
Let's make the remove() function strictly the reverse of the probe()
function so it's easier to reason about.

This patch was created by code inspection and should move us closer to
a proper remove.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210416153909.v4.4.Ifcf1deaa372eba7eeb4f8eb516c5d15b77a657a9@changeid
2021-04-20 08:58:15 -07:00
Douglas Anderson
6b7adaeab6 drm/bridge: ti-sn65dsi86: Remove incorrectly tagged kerneldoc comment
A random comment inside a function had "/**" in front of it. That
doesn't make sense. Remove.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210416153909.v4.3.I167766eeaf4c4646a3934c4dd5332decbab6bd68@changeid
2021-04-20 08:57:58 -07:00
Douglas Anderson
acf3aca5ca drm/bridge: ti-sn65dsi86: Simplify refclk handling
The clock framework makes it simple to deal with an optional clock.
You can call clk_get_optional() and if the clock isn't specified it'll
just return NULL without complaint. It's valid to pass NULL to
enable/disable/prepare/unprepare. Let's make use of this to simplify
things a tiny bit.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210416153909.v4.2.Ic9c04f960190faad5290738b2a35d73661862735@changeid
2021-04-20 08:57:20 -07:00
Lyude Paul
6171261875 drm/bridge/ti-sn65dsi86: (Un)register aux device on bridge attach/detach
Since we're about to add a back-pointer to drm_dev in drm_dp_aux, let's
move the AUX adapter registration to the first point where we know which
DRM device we'll be working with - when the drm_bridge is attached.
Likewise, we unregister the AUX adapter on bridge detachment by adding a
ti_sn_bridge_detach() callback.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219215326.2227596-7-lyude@redhat.com
2021-03-23 14:17:41 -04:00
Stephen Boyd
982f589bde drm/bridge: ti-sn65dsi86: Update reply on aux failures
We should be setting the drm_dp_aux_msg::reply field if a NACK or a
SHORT reply happens. Update the error bit handling logic in
ti_sn_aux_transfer() to handle these cases and notify upper layers that
such errors have happened. This helps the retry logic understand that a
timeout has happened, or to shorten the read length if the panel isn't
able to handle the longest read possible.

Note: I don't have any hardware that exhibits these code paths so this
is written based on reading the datasheet for this bridge and inspecting
the code and how this is called.

Changes in v2:
 - Move WRITE_STATUS_UPDATE check from case to assignment

Changes in v2:
 - Handle WRITE_STATUS_UPDATE properly

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@siol.net>
Cc: Sean Paul <seanpaul@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201102181144.3469197-5-swboyd@chromium.org
2020-11-07 12:06:18 +01:00
Stephen Boyd
58074b08c0 drm/bridge: ti-sn65dsi86: Read EDID blob over DDC
Use the DDC connection to read the EDID from the eDP panel instead of
relying on the panel to tell us the modes.

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@siol.net>
Cc: Sean Paul <seanpaul@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201102181144.3469197-4-swboyd@chromium.org
2020-11-07 12:06:10 +01:00
Stephen Boyd
b38558e305 drm/bridge: ti-sn65dsi86: Make polling a busy loop
There's no reason we need to wait here to poll a register over i2c. The
i2c bus is inherently slow and delays are practically part of the
protocol because we have to wait for the device to respond to any
request for a register. Let's rely on the sleeping of the i2c controller
instead of adding any sort of delay here in the bridge driver.

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@siol.net>
Cc: Sean Paul <seanpaul@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201102181144.3469197-3-swboyd@chromium.org
2020-11-07 12:06:07 +01:00
Stephen Boyd
e4a6c18e60 drm/bridge: ti-sn65dsi86: Combine register accesses in ti_sn_aux_transfer()
These register reads and writes are sometimes directly next to each
other in the register address space. Let's use regmap bulk read/write
APIs to get the data with one transfer instead of multiple i2c
transfers. This helps cut down on the number of transfers in the case of
something like reading an EDID where we read in blocks of 16 bytes at a
time and the last for loop here is sending an i2c transfer for each of
those 16 bytes, one at a time. Ouch!

Changes in v3:
 - Undid changes in v2

Changes in v2:
 - Combined AUX_CMD register write

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@siol.net>
Cc: Sean Paul <seanpaul@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201102181144.3469197-2-swboyd@chromium.org
2020-11-07 12:06:03 +01:00
Xu Wang
06dd6f303f drm/bridge: ti-sn65dsi86: remove redundant null check
Because clk_disable_unprepare already checked NULL clock parameter,
so the additional checks are unnecessary, just remove it

Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200930081859.52431-1-vulab@iscas.ac.cn
2020-10-16 21:04:00 +02:00
Douglas Anderson
137655d1ed drm/bridge: ti-sn65dsi86: Add retries for link training
On some panels hooked up to the ti-sn65dsi86 bridge chip we found that
link training was failing.  Specifically, we'd see:

  ti_sn65dsi86 2-002d: [drm:ti_sn_bridge_enable] *ERROR* Link training failed, link is off (-5)

The panel was hooked up to a logic analyzer and it was found that, as
part of link training, the bridge chip was writing a 0x1 to DPCD
address 00600h and the panel responded NACK.  As can be seen in header
files, the write of 0x1 to DPCD address 0x600h means we were trying to
write the value DP_SET_POWER_D0 to the register DP_SET_POWER.  The
panel vendor says that a NACK in this case is not unexpected and means
"not ready, try again".

In testing, we found that this panel would respond with a NACK in
about 1/25 times.  Adding the retry logic worked fine and the most
number of tries needed was 3.  Just to be safe, we'll add 10 tries
here and we'll add a little blurb to the logs if we ever need more
than 5.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-By: Steev Klimaszewski <steev@kali.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201002135920.1.I2adbc90b2db127763e2444bd5a4e5bf30e1db8e5@changeid
2020-10-16 20:34:24 +02:00
Dave Airlie
ce5c207c6b Linux 5.9-rc4
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Merge tag 'v5.9-rc4' into drm-next

Backmerge 5.9-rc4 as there is a nasty qxl conflict
that needs to be resolved.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2020-09-08 14:41:40 +10:00
Gustavo A. R. Silva
df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Joe Perches
87154ff86b drm: Remove unnecessary drm_panel_attach and drm_panel_detach
These functions are now empty and no longer
useful so remove the functions and their uses.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Bernard Zhao <bernard@vivo.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>,
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Icenowy Zheng <icenowy@aosc.io>,
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Robert Chiras <robert.chiras@nxp.com>
Cc: dri-devel@lists.freedesktop.org,
Cc: linux-kernel@vger.kernel.org
Cc: opensource.kernel@vivo.com
Signed-off-by: Sam Ravnborg <sam@ravnborg.org> # Fixed build and a few warnings
Link: https://patchwork.freedesktop.org/patch/msgid/9e13761020750b1ce2f1fabee23ef6e2a2942882.camel@perches.com
2020-08-08 09:06:33 +02:00
Alexander A. Klimov
ce1995a7e3 drm/bridge: Replace HTTP links with HTTPS ones
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
	  If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
            If both the HTTP and HTTPS versions
            return 200 OK and serve the same content:
              Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200708121604.14292-1-grandmaster@al2klimov.de
2020-07-10 20:21:45 +02:00
Harigovindan P
fbd12537b0 drm/bridge: ti-sn65dsi86: ensure bridge suspend happens during PM sleep
ti-sn65dsi86 bridge is enumerated as a runtime device. When
suspend is triggered, PM core adds a refcount on all the
devices and calls device suspend, since usage count is
already incremented, runtime suspend will not be called
and it kept the bridge regulators and gpios ON which resulted
in platform not entering into XO shutdown.

Add changes to force suspend on the runtime device during pm sleep.

Signed-off-by: Harigovindan P <harigovi@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200609120455.20458-1-harigovi@codeaurora.org
2020-06-26 13:39:59 +02:00
Douglas Anderson
c8fa5b7c7a drm/bridge: ti-sn65dsi86: Check the regmap return value when setting a GPIO
The ti_sn_bridge_gpio_set() got the return value of
regmap_update_bits() but didn't check it.  The function can't return
an error value, but we should at least print a warning if it didn't
work.

This fixes a compiler warning about setting "ret" but not using it.

Fixes: 27ed2b3f22 ("drm/bridge: ti-sn65dsi86: Export bridge GPIOs to Linux")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200612123003.v2.4.Ia4376fd88cdc6e8f8b43c65548458305f82f1d61@changeid
2020-06-18 11:40:38 +02:00
Douglas Anderson
c42fb724cd drm/bridge: ti-sn65dsi86: Fix kernel-doc typo ln_polr => ln_polrs
This fixes a kernel doc warning due to a typo:
  warning: Function parameter or member 'ln_polrs' not described in 'ti_sn_bridge'

Fixes: 5bebaeadb3 ("drm/bridge: ti-sn65dsi86: Implement lane reordering + polarity")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200612123003.v2.3.Ib616e311c48cc64b2cef11bd54d4a9cedc874bb1@changeid
2020-06-18 11:40:38 +02:00
Douglas Anderson
f4946b0a37 drm/bridge: ti-sn65dsi86: Don't use kernel-doc comment for local array
When building we were getting an error:

  warning: cannot understand function prototype:
    'const unsigned int ti_sn_bridge_dp_rate_lut[] = '

Arrays aren't supposed to be marked with "/**" kerneldoc comments.  Fix.

Fixes: a095f15c00 ("drm/bridge: add support for sn65dsi86 bridge driver")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200612123003.v2.2.If3807e4ebf7f0440f64c3069edcfac9a70171940@changeid
2020-06-18 11:40:38 +02:00
Douglas Anderson
9e4f358313 drm/bridge: ti-sn65dsi86: Don't compile GPIO bits if not CONFIG_OF_GPIO
The kernel test robot noted that if "OF" is defined (which is needed
to select DRM_TI_SN65DSI86 at all) but not OF_GPIO that we'd get
compile failures because some of the members that we access in "struct
gpio_chip" are only defined "#if defined(CONFIG_OF_GPIO)".

All the GPIO bits in the driver are all nicely separated out.  We'll
guard them with the same "#if defined" that the header has and add a
little stub function if OF_GPIO is not defined.

Fixes: 27ed2b3f22 ("drm/bridge: ti-sn65dsi86: Export bridge GPIOs to Linux")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200612123003.v2.1.Ibe95d8f3daef01e5c57d4c8c398f04d6a839492c@changeid
2020-06-18 11:40:38 +02:00
Douglas Anderson
5bebaeadb3 drm/bridge: ti-sn65dsi86: Implement lane reordering + polarity
The ti-sn65dsi86 MIPI DSI to eDP bridge chip supports arbitrary
remapping of eDP lanes and also polarity inversion.  Both of these
features have been described in the device tree bindings for the
device since the beginning but were never implemented in the driver.
Implement both of them.

Part of this change also allows you to (via the same device tree
bindings) specify to use fewer than the max number of DP lanes that
the panel reports.  This could be useful if your display supports more
lanes but only a few are hooked up on your board.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200518114656.REPOST.v2.1.Ibc8eeddcee94984a608d6900b46f9ffde4045da4@changeid
2020-05-18 21:37:02 +02:00
Douglas Anderson
fe3d7a3549 drm/bridge: ti-sn65dsi86: Fix off-by-one error in clock choice
If the rate in our table is _equal_ to the rate we want then it's OK
to pick it.  It doesn't need to be greater than the one we want.

Fixes: a095f15c00 ("drm/bridge: add support for sn65dsi86 bridge driver")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200504213225.1.I21646c7c37ff63f52ae6cdccc9bc829fbc3d9424@changeid
2020-05-18 20:29:57 +02:00
Douglas Anderson
baef4d5619 drm/bridge: ti-sn65dsi86: Clear old error bits before AUX transfers
The AUX channel transfer error bits in the status register are latched
and need to be cleared.  Clear them before doing our transfer so we
don't see old bits and get confused.

Without this patch having a single failure would mean that all future
transfers would look like they failed.

Fixes: b814ec6d45 ("drm/bridge: ti-sn65dsi86: Implement AUX channel")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200508163314.1.Idfa69d5d3fc9623083c0ff78572fea87dccb199c@changeid
2020-05-18 20:01:14 +02:00
Douglas Anderson
27ed2b3f22 drm/bridge: ti-sn65dsi86: Export bridge GPIOs to Linux
The ti-sn65dsi86 MIPI DSI to eDP bridge chip has 4 pins on it that can
be used as GPIOs in a system.  Each pin can be configured as input,
output, or a special function for the bridge chip.  These are:
- GPIO1: SUSPEND Input
- GPIO2: DSIA VSYNC
- GPIO3: DSIA HSYNC or VSYNC
- GPIO4: PWM

Let's expose these pins as GPIOs.  A few notes:
- Access to ti-sn65dsi86 is via i2c so we set "can_sleep".
- These pins can't be configured for IRQ.
- There are no programmable pulls or other fancy features.
- Keeping the bridge chip powered might be expensive.  The driver is
  setup such that if all used GPIOs are only inputs we'll power the
  bridge chip on just long enough to read the GPIO and then power it
  off again.  Setting a GPIO as output will keep the bridge powered.
- If someone releases a GPIO we'll implicitly switch it to an input so
  we no longer need to keep the bridge powered for it.

Because of all of the above limitations we just need to implement a
bare-bones GPIO driver.  The device tree bindings already account for
this device being a GPIO controller so we only need the driver changes
for it.

NOTE: Despite the fact that these pins are nominally muxable I don't
believe it makes sense to expose them through the pinctrl interface as
well as the GPIO interface.  The special functions are things that the
bridge chip driver itself would care about and it can just configure
the pins as needed.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
[added pdata->gchip.base = -1;]
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200507143354.v5.1.Ia50267a5549392af8b37e67092ca653a59c95886@changeid
2020-05-18 19:56:51 +02:00
Laurent Pinchart
a25b988ff8 drm/bridge: Extend bridge API to disable connector creation
Most bridge drivers create a DRM connector to model the connector at the
output of the bridge. This model is historical and has worked pretty
well so far, but causes several issues:

- It prevents supporting more complex display pipelines where DRM
connector operations are split over multiple components. For instance a
pipeline with a bridge connected to the DDC signals to read EDID data,
and another one connected to the HPD signal to detect connection and
disconnection, will not be possible to support through this model.

- It requires every bridge driver to implement similar connector
handling code, resulting in code duplication.

- It assumes that a bridge will either be wired to a connector or to
another bridge, but doesn't support bridges that can be used in both
positions very well (although there is some ad-hoc support for this in
the analogix_dp bridge driver).

In order to solve these issues, ownership of the connector should be
moved to the display controller driver (where it can be implemented
using helpers provided by the core).

Extend the bridge API to allow disabling connector creation in bridge
drivers as a first step towards the new model. The new flags argument to
the bridge .attach() operation allows instructing the bridge driver to
skip creating a connector. Unconditionally set the new flags argument to
0 for now to keep the existing behaviour, and modify all existing bridge
drivers to return an error when connector creation is not requested as
they don't support this feature yet.

The change is based on the following semantic patch, with manual review
and edits.

@ rule1 @
identifier funcs;
identifier fn;
@@
 struct drm_bridge_funcs funcs = {
 	...,
 	.attach = fn
 };

@ depends on rule1 @
identifier rule1.fn;
identifier bridge;
statement S, S1;
@@
 int fn(
 	struct drm_bridge *bridge
+	, enum drm_bridge_attach_flags flags
 )
 {
 	... when != S
+	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
+		DRM_ERROR("Fix bridge driver to make connector optional!");
+		return -EINVAL;
+	}
+
 	S1
 	...
 }

@ depends on rule1 @
identifier rule1.fn;
identifier bridge, flags;
expression E1, E2, E3;
@@
 int fn(
 	struct drm_bridge *bridge,
 	enum drm_bridge_attach_flags flags
 ) {
 <...
 drm_bridge_attach(E1, E2, E3
+	, flags
 )
 ...>
 }

@@
expression E1, E2, E3;
@@
 drm_bridge_attach(E1, E2, E3
+	, 0
 )

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200226112514.12455-10-laurent.pinchart@ideasonboard.com
2020-02-26 13:31:23 +02:00
Douglas Anderson
997bac693a drm/bridge: ti-sn65dsi86: Avoid invalid rates
Based on work by Bjorn Andersson <bjorn.andersson@linaro.org>,
Jeffrey Hugo <jeffrey.l.hugo@gmail.com>, and
Rob Clark <robdclark@chromium.org>.

Let's read the SUPPORTED_LINK_RATES and/or MAX_LINK_RATE (depending on
the eDP version of the sink) to figure out what eDP rates are
supported and pick the ideal one.

NOTE: I have only personally tested this code on eDP panels that are
1.3 or older.  Code reading SUPPORTED_LINK_RATES for DP 1.4+ was
tested by hacking the code to pretend that a table was there.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218143416.v3.9.Ib59207b66db377380d13748752d6fce5596462c5@changeid
2020-02-13 10:22:05 +01:00
Douglas Anderson
c2e1ea320d drm/bridge: ti-sn65dsi86: Train at faster rates if slower ones fail
If we fail training at a lower DP link rate let's now keep trying
until we run out of rates to try.  Basically the algorithm here is to
start at the link rate that is the theoretical minimum and then slowly
bump up until we run out of rates or hit the max rate of the sink.  We
query the sink using a DPCD read.

This is, in fact, important in practice.  Specifically at least one
panel hooked up to the bridge (AUO B116XAK01) had a theoretical min
rate more than 1.62 GHz (if run at 24 bpp) and fails to train at the
next rate (2.16 GHz).  It would train at 2.7 GHz, though.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218143416.v3.8.I251add713bc5c97225200894ab110ea9183434fd@changeid
2020-02-13 10:22:05 +01:00
Douglas Anderson
3438ea3dc8 drm/bridge: ti-sn65dsi86: Group DP link training bits in a function
We'll re-organize the ti_sn_bridge_enable() function a bit to group
together all the parts relating to link training and split them into a
sub-function.  This is not intended to have any functional change and
is in preparation for trying link training several times at different
rates.  One small side effect here is that if link training fails
we'll now leave the DP PLL disabled, but that seems like a sane thing
to do.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218143416.v3.7.I1fc75ad11db9048ef08cfe1ab7322753d9a219c7@changeid
2020-02-13 10:22:05 +01:00
Douglas Anderson
37c1d89820 drm/bridge: ti-sn65dsi86: Use 18-bit DP if we can
The current bridge driver always forced us to use 24 bits per pixel
over the DP link.  This is a waste if you are hooked up to a panel
that only supports 6 bits per color or fewer, since in that case you
can run at 18 bits per pixel and thus end up at a lower DP clock rate.

Let's support this.

While at it, let's clean up the math in the function to avoid rounding
errors (and round in the correct direction when we have to round).
Numbers are sufficiently small (because mode->clock is in kHz) that we
don't need to worry about integer overflow.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
[narmstrong: s/ran/can/]
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218143416.v3.6.Iaf8d698f4e5253d658ae283d2fd07268076a7c27@changeid
2020-02-13 10:21:45 +01:00
Douglas Anderson
457622d9f9 drm/bridge: ti-sn65dsi86: Read num lanes from the DP sink
At least one panel hooked up to the bridge (AUO B116XAK01) only
supports 1 lane of DP.  Let's read this information and stop
hardcoding 4 DP lanes.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218143416.v3.5.Idbd0051d0de53f7e9d18a291ea33011c0854fcc6@changeid
2020-02-13 10:21:10 +01:00
Douglas Anderson
cf33de1799 drm/bridge: ti-sn65dsi86: Config number of DP lanes Mo' Betta
The driver used to say that the value to program into bridge register
0x93 was dp_lanes - 1.  Looking at the datasheet for the bridge, this
is wrong.  The data sheet says:
* 1 = 1 lane
* 2 = 2 lanes
* 3 = 4 lanes

A more proper way to express this encoding is min(dp_lanes, 3).

At the moment this change has zero effect because we've hardcoded the
number of DP lanes to 4.  ...and (4 - 1) == min(4, 3).  How fortunate!
...but soon we'll stop hardcoding the number of lanes.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218143416.v3.4.If3e2d0493e7b6e8b510ea90d8724ff760379b3ba@changeid
2020-02-13 10:21:09 +01:00
Douglas Anderson
fa8a66c687 drm/bridge: ti-sn65dsi86: Don't use MIPI variables for DP link
The ti-sn65dsi86 is a bridge from MIPI to DP and thus has two links:
the MIPI link and the DP link.  The two links do not need to have the
same format or number of lanes.  Stop using MIPI variables when
talking about the DP link.

This has zero functional change because:
* currently we are hardcoding the MIPI link as unpacked RGB888 which
  requires 24 bits and currently we are not changing the DP link rate
  from the bridge's default of 8 bits per pixel.
* currently we are hardcoding both the MIPI and DP as being 4 lanes.

This is all in prep for fixing some of the above.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218143416.v3.3.Ia6e05f4961adb0d4a0d32ba769dd7781ee8db431@changeid
2020-02-13 10:21:08 +01:00
Douglas Anderson
2f8fcc7794 drm/bridge: ti-sn65dsi86: zero is never greater than an unsigned int
When we iterate over ti_sn_bridge_dp_rate_lut, there's no reason to
start at index 0 which always contains the value 0.  0 is not a valid
link rate.

This change should have no real effect but is a small cleanup.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218143416.v3.2.Id445d0057bedcb0a190009e0706e9254c2fd48eb@changeid
2020-02-13 10:21:08 +01:00
Douglas Anderson
ca1b885cbe drm/bridge: ti-sn65dsi86: Split the setting of the dp and dsi rates
These two things were in one function.  Split into two.  This looks
like it's duplicating some code, but don't worry.  This is is just in
preparation for future changes.

This is intended to have zero functional change and will just make
future patches easier to understand.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218143416.v3.1.Icb765d5799e9651e5249c0c27627ba33a9e411cf@changeid
2020-02-13 10:21:07 +01:00
Sam Ravnborg
06c4a9c2ae drm/panel: decouple connector from drm_panel
To facilitate moving connector creation to display drivers,
decouple the drm_connector from drm_panel.

This patch adds a connector argument to drm_panel_get_modes().

All users of drm_panel_get_modes() already had the connector
available, so updating users was trivial.

With this patch drm_panel no longer keeps a reference to the drm_connector.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@siol.net>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Alison Wang <alison.wang@nxp.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: CK Hu <ck.hu@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: "Heiko Stübner" <heiko@sntech.de>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Torsten Duwe <duwe@lst.de>
Cc: Vasily Khoruzhick <anarsoul@gmail.com>
Cc: Icenowy Zheng <icenowy@aosc.io>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Cc: Alexios Zavras <alexios.zavras@intel.com>
Cc: Brian Masney <masneyb@onstation.org>
Cc: Rob Clark <robdclark@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Allison Randal <allison@lohutok.net>
Cc: Shayenne Moura <shayenneluzmoura@gmail.com>
Cc: Abhinav Kumar <abhinavk@codeaurora.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-tegra@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20191207140353.23967-7-sam@ravnborg.org
2019-12-09 22:57:26 +01:00
Boris Brezillon
ee68c743f8 drm: Stop including drm_bridge.h from drm_crtc.h
We are about to add a drm_bridge_state that inherits from
drm_private_state which is defined in drm_atomic.h. Problem is,
drm_atomic.h includes drm_crtc.h which in turn includes drm_bridge.h,
leading to "drm_private_state has incomplete type" error.

Let's force all users of the drm_bridge API to explicitly include
drm_bridge.h.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190826152649.13820-2-boris.brezillon@collabora.com
2019-08-28 22:11:03 +02:00
Rob Clark
66a639cbe3 drm/bridge: ti-sn65dsi86: use dev name for debugfs
This should be more future-proof if we ever encounter a device with two
of these bridges.

Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190706203105.7810-1-robdclark@gmail.com
2019-07-16 09:53:03 +02:00
Rob Clark
67b587934c drm/bridge: ti-sn65dsi86: correct dsi mode_flags
Noticed while comparing register dump of how bootloader configures DSI
vs how kernel configures.  It seems the bridge still works either way,
but fixing this clears the 'CHA_DATATYPE_ERR' error status bit.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190702154419.20812-4-robdclark@gmail.com
2019-07-04 15:10:08 +02:00
Rob Clark
8efb243a5c drm/bridge: ti-sn65dsi86: add debugfs
Add a debugfs file to show status registers.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190702154419.20812-3-robdclark@gmail.com
2019-07-04 15:05:36 +02:00
Rob Clark
5c27d6078c drm/bridge: ti-sn65dsi86: add link to datasheet
The bridge has pretty good docs, lets add a link to make them easier to
find.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190702154419.20812-2-robdclark@gmail.com
2019-07-04 15:05:34 +02:00
Sam Ravnborg
95b608044f drm/bridge: drop drmP.h usage
Drop use of the deprecated drmP.h header file.

While touching the list of include files:
- Divide include files in blocks of linux/* drm/* etc.
- Sort individual blocks of include files
- Remove duplicated header file

v2:
- Be consistent in the order of the include blocks (Laurent)

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: Martin Donnelly <martin.donnelly@ge.com>
Cc: Martyn Welch <martyn.welch@collabora.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190519183636.19588-1-sam@ravnborg.org
2019-05-26 10:55:04 +02:00
Daniel Vetter
fcd70cd36b drm: Split out drm_probe_helper.h
Having the probe helper stuff (which pretty much everyone needs) in
the drm_crtc_helper.h file (which atomic drivers should never need) is
confusing. Split them out.

To make sure I actually achieved the goal here I went through all
drivers. And indeed, all atomic drivers are now free of
drm_crtc_helper.h includes.

v2: Make it compile. There was so much compile fail on arm drivers
that I figured I'll better not include any of the acks on v1.

v3: Massive rebase because i915 has lost a lot of drmP.h includes, but
not all: Through drm_crtc_helper.h > drm_modeset_helper.h -> drmP.h
there was still one, which this patch largely removes. Which means
rolling out lots more includes all over.

This will also conflict with ongoing drmP.h cleanup by others I
expect.

v3: Rebase on top of atomic bochs.

v4: Review from Laurent for bridge/rcar/omap/shmob/core bits:
- (re)move some of the added includes, use the better include files in
  other places (all suggested from Laurent adopted unchanged).
- sort alphabetically

v5: Actually try to sort them, and while at it, sort all the ones I
touch.

v6: Rebase onto i915 changes.

v7: Rebase once more.

Acked-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Acked-by: CK Hu <ck.hu@mediatek.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: virtualization@lists.linux-foundation.org
Cc: etnaviv@lists.freedesktop.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-amlogic@lists.infradead.org
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: nouveau@lists.freedesktop.org
Cc: spice-devel@lists.freedesktop.org
Cc: amd-gfx@lists.freedesktop.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Cc: linux-tegra@vger.kernel.org
Cc: xen-devel@lists.xen.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190117210334.13234-1-daniel.vetter@ffwll.ch
2019-01-24 13:20:42 +01:00
Sandeep Panda
4265b0fe45 drm/bridge: fix AUX_CMD_SEND bit value for ti, sn65dsi86 bridge
Fix the AUX_CMD_SEND bit for ti,sn65dsi86 bridge chip. With wrong
value the dpcd aux transactions with eDP panel are failing.

Signed-off-by: Sandeep Panda <spanda@codeaurora.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20181130092745.4219-1-spanda@codeaurora.org
2018-11-30 10:45:06 -05:00
Douglas Anderson
c2bfc22388 drm/bridge: ti-sn65dsi86: Remove the mystery delay
Let's solve the mystery of commit bf1178c989 ("drm/bridge:
ti-sn65dsi86: Add mystery delay to enable()").  Specifically the
reason we needed that mystery delay is that we weren't paying
attention to HPD.

Looking at the datasheet for the same panel that was tested for the
original commit, I see there's a timing "t3" that times from power on
to the aux channel being operational.  This time is specced as 0 - 200
ms.  The datasheet says that the aux channel is operational at exactly
the same time that HPD is asserted.

Scoping the signals on this board showed that HPD was asserted 84 ms
after power was asserted.  That very closely matches the magic 70 ms
delay that we had.  ...and actually, in my testing the 70 ms wasn't
quite enough of a delay and some percentage of the time the display
didn't come up until I bumped it to 100 ms (presumably 84 ms would
have worked too).

To solve this, we tried to hook up the HPD signal in the bridge.
...but in doing so we found that that the bridge didn't report that
HPD was asserted until ~280 ms after we powered it (!).  This is
explained by looking at the sn65dsi86 datasheet section "8.4.5.1 HPD
(Hot Plug/Unplug Detection)".  Reading there we see that the bridge
isn't even intended to report HPD until 100 ms after it's asserted.
...but that would have left us at 184 ms.  The extra 100 ms
(presumably) comes from this part in the datasheet:

> The HPD state machine operates off an internal ring oscillator. The
> ring oscillator frequency will vary [ ... ]. The min/max range in
> the HPD State Diagram refers to the possible times based off
> variation in the ring oscillator frequency.

Given that the 280 ms we'll end up delaying if we hook up HPD is
_slower_ than the 200 ms we could just hardcode, for now we'll solve
the problem by just hardcoding a 200 ms delay in the panel driver
using the patch in this series ("drm/panel: simple: Support panels
with HPD where HPD isn't connected").

If we later find a panel that needs to use this bridge where we need
HPD then we'll have to come up with some new code to handle it.  Given
the silly debouncing in the bridge chip, though, it seems unlikely.

One last note is that I tried to solve this through another way: In
ti_sn_bridge_enable() I tried to use various combinations of
dp_dpcd_writeb() and dp_dpcd_readb() to detect when the aux channel
was up.  In theory that would let me detect _exactly_ when I could
continue and do link training.  Unfortunately even if I did an aux
transfer w/out waiting I couldn't see any errors.  Possibly I could
keep looping over link training until it came back with success, but
that seemed a little overly hacky to me.

Reviewed-by: Sean Paul <sean@poorly.run>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20181025222134.174583-4-dianders@chromium.org
2018-10-29 11:53:27 -04:00
Sean Paul
bf1178c989 drm/bridge: ti-sn65dsi86: Add mystery delay to enable()
This patch adds a 70ms mystery delay to the bridge driver in enable.
By experimentation, it seems like it can go anywhere up until we
initiate semi-auto link training. If we don't have the delay, link
training fails.

I tried to root cause this as best I could, but neither the datasheet
for the panel nor the bridge mention a delay of this magnitude in their
timing requirements. So for now, add the mystery delay until someone
figures out a better fix.

Changes in v3:
- Added to the set

Cc: Sandeep Panda <spanda@codeaurora.org>
Reviewed-by: Sandeep Panda <spanda@codeaurora.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180813213058.184821-8-sean@poorly.run
2018-08-27 10:57:20 -04:00
Sean Paul
638e9af16b drm/bridge: ti-sn65dsi86: Poll for training complete
Instead of just waiting 20ms for training to complete, actually poll the
status to ensure training is finished.

Changes in v3:
- Added to the set

Cc: Sandeep Panda <spanda@codeaurora.org>
Reviewed-by: Sandeep Panda <spanda@codeaurora.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180813213058.184821-7-sean@poorly.run
2018-08-14 14:06:13 -04:00
Sean Paul
fc52d0ed11 drm/bridge: ti-sn65dsi86: Poll for DP PLL Lock
Instead of just waiting and hoping, actually poll for the pll lock to be
acquired. As a bonus, this should be significantly faster than the
sleep.

Changes in v3:
- Added to the set

Cc: Sandeep Panda <spanda@codeaurora.org>
Reviewed-by: Sandeep Panda <spanda@codeaurora.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180813213058.184821-6-sean@poorly.run
2018-08-14 14:06:01 -04:00
Sean Paul
73c89ead71 drm/bridge: ti-sn65dsi86: Move panel_prepare() to pre_enable()
prepare() is the old-timey way to say pre_enable(). It should be called
before modeset. This fixes an issue where the panel on cheza must have
the regulator always-on/boot-on for it to work.

Changes in v3:
- Added to the set

Cc: Sandeep Panda <spanda@codeaurora.org>
Reviewed-by: Sandeep Panda <spanda@codeaurora.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180813213058.184821-5-sean@poorly.run
2018-08-14 14:05:47 -04:00