drm/bridge: parade-ps8640: Make sure we drop the AUX mutex in the error case

After commit 26db46bc9c67 ("drm/bridge: parade-ps8640: Ensure bridge
is suspended in .post_disable()"), if we hit the error case in
ps8640_aux_transfer() then we return without dropping the mutex. Fix
this oversight.

Fixes: 26db46bc9c67 ("drm/bridge: parade-ps8640: Ensure bridge is suspended in .post_disable()")
Reviewed-by: Hsin-Yi Wang <hsinyi@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240117103502.1.Ib726a0184913925efc7e99c4d4fc801982e1bc24@changeid

drm/bridge: parade-ps8640: Ensure bridge is suspended in .post_disable()

The ps8640 bridge seems to expect everything to be power cycled at the
disable process, but sometimes ps8640_aux_transfer() holds the runtime
PM reference and prevents the bridge from suspend.

Prevent that by introducing a mutex lock between ps8640_aux_transfer()
and .post_disable() to make sure the bridge is really powered off.

Fixes: 826cff3f7ebb ("drm/bridge: parade-ps8640: Enable runtime power management")
Signed-off-by: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240109120528.1292601-1-treapking@chromium.org

drm/bridge: parade-ps8640: Wait for HPD when doing an AUX transfer

Unlike what is claimed in commit f5aa7d46b0ee ("drm/bridge:
parade-ps8640: Provide wait_hpd_asserted() in struct drm_dp_aux"), if
someone manually tries to do an AUX transfer (like via `i2cdump ${bus}
0x50 i`) while the panel is off we don't just get a simple transfer
error. Instead, the whole ps8640 gets thrown for a loop and goes into
a bad state.

Let's put the function to wait for the HPD (and the magical 50 ms
after first reset) back in when we're doing an AUX transfer. This
shouldn't actually make things much slower (assuming the panel is on)
because we should immediately poll and see the HPD high. Mostly this
is just an extra i2c transfer to the bridge.

Fixes: f5aa7d46b0ee ("drm/bridge: parade-ps8640: Provide wait_hpd_asserted() in struct drm_dp_aux")
Tested-by: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: Pin-yen Lin <treapking@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231221135548.1.I10f326a9305d57ad32cee7f8d9c60518c8be20fb@changeid

drm/bridge: ps8640: Fix size mismatch warning w/ len

After commit 26195af57798 ("drm/bridge: ps8640: Drop the ability of
ps8640 to fetch the EDID"), I got an error compiling:

error: comparison of distinct pointer types
('typeof (len) *' (aka 'unsigned int *') and
'typeof (msg->size) *' (aka 'unsigned long *'))
[-Werror,-Wcompare-distinct-pointer-types]

Fix it by declaring the `len` as size_t.

The above error only shows up on downstream kernels without commit
d03eba99f5bf ("minmax: allow min()/max()/clamp() if the arguments have
the same signedness."), but since commit 26195af57798 ("drm/bridge:
ps8640: Drop the ability of ps8640 to fetch the EDID") is a "Fix" that
will likely be backported it seems nice to make it easy. ...plus it's
more correct to declare `len` as size_t anyway.

Fixes: 26195af57798 ("drm/bridge: ps8640: Drop the ability of ps8640 to fetch the EDID")
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231218090454.1.I5c6eb80b2f746439c4b58efab788e00701d08759@changeid

drm/bridge: parade-ps8640: Never store more than msg->size bytes in AUX xfer

While testing, I happened to notice a random crash that looked like:

Kernel panic - not syncing: stack-protector:
Kernel stack is corrupted in: drm_dp_dpcd_probe+0x120/0x120

Analysis of drm_dp_dpcd_probe() shows that we pass in a 1-byte buffer
(allocated on the stack) to the aux->transfer() function. Presumably
if the aux->transfer() writes more than one byte to this buffer then
we're in a bad shape.

Dropping into kgdb, I noticed that "aux->transfer" pointed at
ps8640_aux_transfer().

Reading through ps8640_aux_transfer(), I can see that there are cases
where it could write more bytes to msg->buffer than were specified by
msg->size. This could happen if the hardware reported back something
bogus to us. Let's fix this so we never write more than msg->size
bytes. We'll still read all the bytes from the hardware just in case
the hardware requires it since the aux transfer data comes through an
auto-incrementing register.

NOTE: I have no actual way to reproduce this issue but it seems likely
this is what was happening in the crash I looked at.

Fixes: 13afcdd7277e ("drm/bridge: parade-ps8640: Add support for AUX channel")
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231214123752.v3.1.I9d1afcaad76a3e2c0ca046dc4adbc2b632c22eda@changeid

drm/bridge: ps8640: Drop the ability of ps8640 to fetch the EDID

In order to read the EDID from an eDP panel, you not only need to
power on the bridge chip itself but also the panel. In the ps8640
driver, this was made to work by having the bridge chip manually power
the panel on by calling pre_enable() on everything connectorward on
the bridge chain. This worked OK, but...

...when trying to do the same thing on ti-sn65dsi86, feedback was that
this wasn't a great idea. As a result, we designed the "DP AUX"
bus. With the design we ended up with the panel driver itself was in
charge of reading the EDID. The panel driver could power itself on and
the bridge chip was able to power itself on because it implemented the
DP AUX bus.

Despite the fact that we came up with a new scheme, implemented in on
ti-sn65dsi86, and even implemented it on parade-ps8640, we still kept
the old code around. This was because the new scheme required a DT
change. Previously the panel was a simple "platform_device" and in DT
at the top level. With the new design the panel needs to be listed in
DT under the DP controller node. The old code allowed us to properly
fetch EDIDs with ps8640 with the old DTs.

Unfortunately, the old code stopped working as of commit 102e80d1fa2c
("drm/bridge: ps8640: Use atomic variants of drm_bridge_funcs"). There
are cases at bootup where connector->state->state is NULL and the
kernel crashed at:
* drm_atomic_bridge_chain_pre_enable
* drm_atomic_get_old_bridge_state
* drm_atomic_get_old_private_obj_state

The crash went away at commit 4fb912e5e190 ("drm/bridge: Introduce
pre_enable_prev_first to alter bridge init order") which added a NULL
check. However, even though we were no longer crashing the end result
was that we weren't actually powering the panel on when we thought we
were. Things could end up working (despite warning splats) if
userspace was persistent and tried to get the mode again, but it
wasn't great.

A bit of digging was done to see if there was an easy fix but there
was nothing obvious. Instead, the only device using ps8640 the "old"
way had its DT updated so that the panel was no longer a simple
"platform_deice". See commit c2d94f72140a ("arm64: dts: mediatek:
mt8173-elm: Move display to ps8640 auxiliary bus") and commit
113b5cc06f44 ("arm64: dts: mediatek: mt8173-elm: remove panel model
number in DT").

Let's delete the old broken code so nobody gets tempted to copy it or
figure out how it works (since it doesn't).

NOTE: from a device tree "purist" point of view, we're supposed to
keep old device trees working and this patch is technically "against
policy". Reasons I'm still proposing it anyway:
1. Officially, old mt8173-elm device trees worked via the "little
white lie" approach. The DT would list an arbitrary/representative
panel that would be used for power sequencing. The mode information
in the panel driver would then be ignored / overridden by the EDID
reading code in ps8640. I don't feel too terrible breaking DTs that
contained the wrong "compatible" string to begin with. NOTE that
any old device trees that _didn't_ lie about their compatible will
still work because the mode information will come from the
hardcoded panels in panel-edp.
2. The only users of the old code were Chromebooks and Chromebooks
don't bake their DTs into the BIOS (they are bundled with the
kernel). Thus we don't need to worry about breaking someone using
an old DT with a new kernel.
3. The old code was broken anyway. If someone wants to fix the old
code instead of deleting it then they have my blessing, but without
a proper fix the old code isn't useful.

Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230616165517.v2.1.I7b8f60b3fbfda068f9bf452d584dc934494bfbfa@changeid

drm: Switch i2c drivers back to use .probe()

After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498b5 ("i2c: Switch .probe() to not take an id parameter") convert
back to (the new) .probe() to be able to eventually drop .probe_new() from
struct i2c_driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Martyn Welch <martyn.welch@collabora.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230526090709.1517297-1-u.kleine-koenig@pengutronix.de

drm/bridge: ps8640: Use constant sleep time for polling hpd

The default hpd_wait_us in panel_edp.c is 2 seconds. This makes the
sleep time in the polling of _ps8640_wait_hpd_asserted become 200ms.
Change it to a constant 20ms to speed up the function.

Signed-off-by: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230331030204.1179524-1-treapking@chromium.org

drm/bridge: ps8640: Return NULL immediately when EDID read fail

drm_edid_read returns NULL on error, so feeding it directly into
drm_edid_duplicate may lead to NULL pointer dereference. Add a check to
guard this.

Fixes: 6a17b4d1b52f ("drm/bridge: ps8640: Add a cache for EDID")
Signed-off-by: Pin-yen Lin <treapking@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230324035909.1727356-1-treapking@chromium.org

drm/bridge: ps8640: Add a cache for EDID

When there are multiple EDID reads, the bridge will be repeatedly
enabled and disabled. Add a cache for EDID to speed this up.

Signed-off-by: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230315035508.2874915-2-treapking@chromium.org

drm/bridge: ps8640: Skip redundant bridge enable

Skip the drm_bridge_chain_pre_enable call when the bridge is already
pre_enabled. This make pre_enable and post_disable (thus
pm_runtime_get/put) symmetric.

Fixes: 46f206304db0 ("drm/bridge: ps8640: Rework power state handling")
Signed-off-by: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230315035508.2874915-1-treapking@chromium.org

drm/bridge: ps8640: Use atomic variants of drm_bridge_funcs

The atomic variants of enable/disable in drm_bridge_funcs are the
preferred operations - introduce these.

The ps8640 driver used the non-atomic variants of the drm_bridge_chain_pre_enable/
drm_bridge_chain_post_disable - convert these to the atomic variants.

v2:
- Init state operations in drm_bridge_funcs (Laurent)

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Cc: Jitao Shi <jitao.shi@mediatek.com>
Cc: Philip Chen <philipchen@chromium.org>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20221205173328.1395350-2-dave.stevenson@raspberrypi.com
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

drm/bridge/parade-ps8640: Extend autosuspend

Same change as done for panel-samsung-atna33xc20. Extend the autosuspend
delay to avoid oscillating between power status during boot.

Signed-off-by: Drew Davenport <ddavenport@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221117133655.4.If6153da69ec4bc9e83d5f095ef6e6b07283940a5@changeid

drm/bridge: ps8640: Add software to support aux defer

This chip can not handle aux defer if the host directly program
its aux registers to access edid/dpcd. So we need let software
to handle the aux defer situation.

Signed-off-by: Jason Yen <jason.yen@paradetech.corp-partner.google.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220930042506.2529522-1-jason.yen@paradetech.corp-partner.google.com

drm/bridge: ps8640: Add back the 50 ms mystery delay after HPD

Back in commit 826cff3f7ebb ("drm/bridge: parade-ps8640: Enable
runtime power management") we removed a mysterious 50 ms delay because
"Parade's support [couldn't] explain what the delay [was] for".

While I'm always a fan of removing mysterious delays, I suspect that
we need this mysterious delay to avoid some problems.

Specifically, what I found recently is that on sc7180-trogdor-homestar
sometimes the AUX backlight wasn't initializing properly. Some
debugging showed that the drm_dp_dpcd_read() function that the AUX
backlight driver was calling was returning bogus data about 1% of the
time when I booted up. This confused
drm_panel_dp_aux_backlight(). From continued debugging:
- If I retried the read then the read worked just fine.
- If I added a loop to perform the same read that
drm_panel_dp_aux_backlight() was doing 30 times at bootup I could
see that some percentage of the time the first read would give bogus
data but all 29 additional reads would always be fine.
- If I added a large delay _after_ powering on the panel but before
powering on PS8640 I could still reproduce the problem.
- If I added a delay after PS8640 powered on then I couldn't reproduce
the problem.
- I couldn't reproduce the problem on a board with the same panel but
the ti-sn65dsi86 bridge chip.

To me, the above indicated that there was a problem with PS8640 and
not the panel.

I don't really have any insight into what's going on in the MCU, but
my best guess is that when the MCU itself sees the HPD go high that it
does some AUX transfers itself and this is confusing things.

Let's go back and add back in the mysterious 50 ms delay. We only want
to do this the first time we see HPD go high after booting the MCU,
not every time we double-check HPD.

With this, the backlight initializes reliably on homestar.

Fixes: 826cff3f7ebb ("drm/bridge: parade-ps8640: Enable runtime power management")
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221017121813.1.I59700c745fbc31559a5d5c8e2a960279c751dbd5@changeid

drm/bridge: ps8640: Add double reset T4 and T5 to power-on sequence

The double reset power-on sequence is a workaround for the hardware
flaw in some chip that SPI Clock output glitch and cause internal MPU
unable to read firmware correctly. The sequence is suggested in ps8640
application note.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Rock Chiu <rock.chiu@paradetech.corp-partner.google.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220815093905.134164-1-hsinyi@chromium.org

drm/bridge: parade-ps8640: Fix regulator supply order

The datasheet says that VDD12 must be enabled and at full voltage before
VDD33 is enabled.

Reorder the bulk regulator supply names so that VDD12 is enabled before
VDD33. Any enable ramp delays should be handled by setting proper
constraints on the regulators.

Fixes: bc1aee7fc8f0 ("drm/bridge: Add I2C based driver for ps8640 bridge")
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220721092258.3397461-1-wenst@chromium.org

drm/bridge: parade-ps8640: Provide wait_hpd_asserted() in struct drm_dp_aux

This implements the callback added by the patch ("drm/dp: Add
wait_hpd_asserted() callback to struct drm_dp_aux").

With this change and all the two "DP AUX Endpoint" drivers changed to
use wait_hpd_asserted(), we no longer need to have an long delay in
the AUX transfer function. It's up to the panel code to make sure that
the panel is powered now. If someone tried to call the aux transfer
function without making sure the panel is powered we'll just get a
normal transfer failure.

We'll still keep the wait for HPD in the pre_enable() function. Though
it's probably not actually needed there, this driver is used in the
old mode (pre-DP AUX Endpoints) and it may be important for those
cases. If nothing else, it shouldn't cause any big problems.

NOTE: When handling the timeout for HPD we start the timer _after_
we've runtime resumed the device. This is definitely important for the
panel on my homestar which comes up 170 ms after we start timing (the
panel specifies 200 ms max). It's a little unclear how much of this
extra time is due to some internal state machine in the parade
firmware vs. debouncing but it seems to work for the two test cases I
have to do it this way.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220614145327.v4.4.Ie827321ce263be52fdb8c1276f6f8cc00d78029f@changeid

drm: Drop drm_edid.h from drm_crtc.h

drm_crtc.h has no need for drm_edid.h, so don't include it.
Avoids useless rebuilds of the entire universe when
touching drm_edid.h.

Quite a few placs do currently depend on drm_edid.h without
actually including it directly. All of those need to be fixed
up.

v2: Fix up i915 and msm some more
v3: Fix alphabetical ordering (Sam)

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220614090245.30283-1-ville.syrjala@linux.intel.com
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>

drm/bridge: parade-ps8640: Handle DP AUX more properly

While it works, for the most part, to assume that the panel has
finished probing when devm_of_dp_aux_populate_ep_devices() returns,
it's a bit fragile. This is talked about at length in commit
a1e3667a9835 ("drm/bridge: ti-sn65dsi86: Promote the AUX channel to
its own sub-dev").

When reviewing the ps8640 code, I managed to convince myself that it
was OK not to worry about it there and that maybe it wasn't really
_that_ fragile. However, it turns out that it really is. Simply
hardcoding panel_edp_probe() to return -EPROBE_DEFER was enough to put
the boot process into an infinite loop. I believe this manages to trip
the same issues that we used to trip with the main MSM code where
something about our actions trigger Linux to re-probe previously
deferred devices right away and each time we try again we re-trigger
Linux to re-probe.

Let's fix this using the callback introduced in the patch ("drm/dp:
Callbacks to make it easier for drivers to use DP AUX bus properly").
When using the new callback, we have to be a little careful. The
probe_done() callback is no longer always called in the context of
our probe routine. That means we can't rely on being able to return
-EPROBE_DEFER from it. We re-jigger the order of things a bit to
account for that.

With this change, the device still boots (though obviously the panel
doesn't come up) if I force panel-edp to always return
-EPROBE_DEFER. If I fake it and make the panel probe exactly once it
also works.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220510122726.v3.4.Ia6324ebc848cd40b4dbd3ad3289a7ffb5c197779@changeid

drm/bridge: simplify the return expression of ps8640_bridge_host_attach

Simplify the return expression.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220429055145.3852271-1-chi.minghao@zte.com.cn

drm: Rename dp/ to display/

Rename dp/ to display/ to account for additional display-related
helpers, such as HDMI. Update all related include statements. No
functional changes.

Various drivers, such as i915 and amdgpu, use similar naming scheme
by putting code for video-output standards into a local display/
directory. The new directory's name is aligned with this convention.

v2:
* update commit message (Javier)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220421073108.19226-3-tzimmermann@suse.de

drm/bridge: parade-ps8640: switch to devm_drm_of_get_bridge

The function "drm_of_find_panel_or_bridge" has been deprecated in
favor of "devm_drm_of_get_bridge".

Switch to the new function and reduce boilerplate.

Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220228183131.23494-1-jose.exposito89@gmail.com

drm/dp: Move DisplayPort AUX bus helpers into dp/

Move drm_dp_aux_bus.c and its header file into the DP subdirectory
and update all users. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220114114535.29157-6-tzimmermann@suse.de

drm/dp: Move public DisplayPort headers into dp/

Move all public DisplayPort headers into dp/ and update users. No
functional changes.

v3:
* rebased onto latest drm-tip

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220114114535.29157-5-tzimmermann@suse.de

drm/bridge: parade-ps8640: Link device to ensure suspend/resume order

Entering suspend while the display attached to this bridge is still on
makes the resume sequence to resume the bridge first, display last:
when this happens, we get a timeout while resuming the bridge, as its
MCU will get stuck due to the display being unpowered.

On the other hand, on mt8173-elm, closing the lid makes the display to
get powered off first, bridge last, so at resume time the sequence is
swapped (compared to the first example) and everything just works
as expected.

Add a stateless device link to the DRM device that this bridge belongs
to, ensuring a correct resume sequence and solving the unability to
correctly resume bridge operation in the first mentioned example.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220105090802.73564-1-angelogioacchino.delregno@collabora.com
Reviewed-by: Robert Foss <robert.foss@linaro.org>

drm/bridge: parade-ps8640: Add backpointer to drm_device in drm_dp_aux

When we added the support for the AUX channel in commit 13afcdd7277e
("drm/bridge: parade-ps8640: Add support for AUX channel") we forgot
to set "drm_dev" to avoid the warning splat at the beginning of
drm_dp_aux_register(). Since everything was working I guess I never
noticed the splat when testing against mainline. In any case, it's
easy to fix. This is basically just like commit 6cba3fe43341 ("drm/dp:
Add backpointer to drm_device in drm_dp_aux") but just for the
parade-ps8640.

Fixes: 13afcdd7277e ("drm/bridge: parade-ps8640: Add support for AUX channel")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Philip Chen <philipchen@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211206162907.1.I1f5d1eba741e4663050ec1b8e39a753f6e42e38b@changeid

drm/bridge: parade-ps8640: Fix additional suspend/resume at bootup

Through log and waveform, we can see that there will be additional
suspend/resume when booting. This timing does not meet the ps8640 spec.
It seems that the delay of 500ms does not satisfied drm_panel_get_modes.
I increased it to 900ms and it seems that this problem can be solved.
To be safe, I'd just round up to a full 1000.

Signed-off-by: yangcong <yangcong5@huaqin.corp-partner.google.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211112084302.2447931-1-yangcong5@huaqin.corp-partner.google.com

drm/bridge: parade-ps8640: Populate devices on aux-bus

Conventionally, panel is listed under the root of the device tree.
When userland asks for display mode, ps8640 bridge is responsible
for returning EDID when ps8640_bridge_get_edid() is called.

Now enable a new option of listing panel under "aux-bus" of ps8640
bridge node in the device tree. In this case, panel driver can retrieve
EDID by triggering AUX transactions, without ps8640_bridge_get_edid()
calls at all.

To prevent the "old" and "new" options from interfering with each
other's logic flow, disable DRM_BRIDGE_OP_EDID when the new option
is taken.

Signed-off-by: Philip Chen <philipchen@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211028105754.v5.2.I09899dea340f11feab97d719cb4b62bef3179e4b@changeid

drm/bridge: parade-ps8640: Enable runtime power management

Fit ps8640 driver into runtime power management framework:

First, break _poweron() to 3 parts: (1) turn on power and wait for
ps8640's internal MCU to finish init (2) check panel HPD (which is
proxied by GPIO9) (3) the other configs. As runtime_resume() can be
called before panel is powered, we only add (1) to _resume() and leave
(2)(3) to _pre_enable(). We also add (2) to _aux_transfer() as we want
to ensure panel HPD is asserted before we start AUX CH transactions.

Second, the original driver has a mysterious delay of 50 ms between (2)
and (3). Since Parade's support can't explain what the delay is for,
and we don't see removing the delay break any boards at hand, remove
the delay to fit into this driver change.

In addition, rename "powered" to "pre_enabled" and don't check for it
in the pm_runtime calls. The pm_runtime calls are already refcounted
so there's no reason to check there. The other user of "powered",
_get_edid(), only cares if pre_enable() has already been called.

Lastly, change some existing DRM_...() logging to dev_...() along the
way, since DRM_...() seem to be deprecated in [1].

[1] https://patchwork.freedesktop.org/patch/454760/

Signed-off-by: Philip Chen <philipchen@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
[dianders: fixed whitespace warning reported by dim tool]
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211028105754.v5.1.I828f5db745535fb7e36e8ffdd62d546f6d08b6d1@changeid

drm/bridge: ps8640: Register and attach our DSI device at probe

In order to avoid any probe ordering issue, the best practice is to move
the secondary MIPI-DSI device registration and attachment to the
MIPI-DSI host at probe time. Let's do this.

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20211025151536.1048186-13-maxime@cerno.tech

drm/bridge: ps8640: Switch to devm MIPI-DSI helpers

Let's switch to the new devm MIPI-DSI function to register and attach
our secondary device. This also avoids leaking the device on removal.

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20211025151536.1048186-12-maxime@cerno.tech

drm/bridge: parade-ps8640: Add support for AUX channel

Implement the first version of AUX support, which will be useful as
we expand the driver to support varied use cases.

Signed-off-by: Philip Chen <philipchen@chromium.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
[dianders: whitespace fixes reported by dim apply-branch]
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210921110556.v6.2.I1d6ea362dc76efa77cca2b46253d31b7651eaf17@changeid

drm/bridge: parade-ps8640: Use regmap APIs

Replace the direct i2c access (i2c_smbus_* functions) with regmap APIs,
which will simplify the future update on ps8640 driver.

Signed-off-by: Philip Chen <philipchen@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
[dianders: whitespace fixes reported by dim apply-branch]
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210921110556.v6.1.I2351df94f18d5d8debc22d4d100f36fac560409a@changeid

drm/bridge: parade-ps8640: Reorg the macros

Reorg the macros as follows:
(1) Group the registers on the same page together.
(2) Group the register and its bit operation together while indenting
the macros of the bit operation with one space.

Also fix a misnomer for the number of mipi data lanes.

Signed-off-by: Philip Chen <philipchen@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210824181140.v2.1.I8ead7431357409f2526e5739ec5bc3ddfd242243@changeid

drm/bridge: ps8640: Rework power state handling

The get_edid() callback can be triggered anytime by an ioctl, i.e

drm_mode_getconnector (ioctl)
-> drm_helper_probe_single_connector_modes
-> drm_bridge_connector_get_modes
-> ps8640_bridge_get_edid

Actually if the bridge pre_enable() function was not called before
get_edid(), the driver will not be able to get the EDID properly and
display will not work until a second get_edid() call is issued and if
pre_enable() is called before. The side effect of this, for example, is
that you see anything when `Frecon` starts, neither the splash screen,
until the graphical session manager starts.

To fix this we need to make sure that all we need is enabled before
reading the EDID. This means the following:

1. If get_edid() is called before having the device powered we need to
power on the device. In such case, the driver will power off again the
device.

2. If get_edid() is called after having the device powered, all should
just work. We added a powered flag in order to avoid recurrent calls
to ps8640_bridge_poweron() and unneeded delays.

3. This seems to be specific for this device, but we need to make sure
the panel is powered on before do a power on cycle on this device.
Otherwise the device fails to retrieve the EDID.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Bilal Wasim <bwasim.lkml@gmail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200827085911.944899-2-enric.balletbo@collabora.com

drm/bridge: ps8640: Print an error if VDO control fails

Print an error message inside ps8640_bridge_vdo_control() function when
it fails so we can simplify a bit the callers, they will only need to
check the error code.

Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Bilal Wasim <bwasim.lkml@gmail.com>
Tested-by: Bilal Wasim <bwasim.lkml@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200826081526.674866-5-enric.balletbo@collabora.com

drm/bridge: ps8640: Return an error for incorrect attach flags

Bridge drivers that implement the new model only shall return an error
from their attach() handler when the DRM_BRIDGE_ATTACH_NO_CONNECTOR flag
is not set. So make sure we return an error because only the new
drm_bridge model is supported.

Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Bilal Wasim <bwasim.lkml@gmail.com>
Tested-by: Bilal Wasim <bwasim.lkml@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200826081526.674866-4-enric.balletbo@collabora.com

drm/bridge: ps8640: Get the EDID from eDP control

The PS8640 DSI-to-eDP bridge can retrieve the EDID, so implement the
.get_edid callback and set the flag to indicate the core to use it.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200826081526.674866-3-enric.balletbo@collabora.com

drm/bridge: ps8640: Let panel to set the connector type

The panel connector type should be set by the panel not the bridge, so
remove the connector_type assignment.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200416164404.2418426-2-enric.balletbo@collabora.com

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

drm/bridge: Add I2C based driver for ps8640 bridge

This patch adds drm_bridge driver for parade DSI to eDP bridge chip.

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
[uli: followed API changes, removed FW update feature]
Signed-off-by: Ulrich Hecht <uli@fpond.eu>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191230090419.137141-3-enric.balletbo@collabora.com