Memory for the "struct device" for any given device isn't supposed to
be released until the device's release() is called. This is important
because someone might be holding a kobject reference to the "struct
device" and might try to access one of its members even after any
other cleanup/uninitialization has happened.
Code analysis of ti-sn65dsi86 shows that this isn't quite right. When
the code was written, it was believed that we could rely on the fact
that the child devices would all be freed before the parent devices
and thus we didn't need to worry about a release() function. While I
still believe that the parent's "struct device" is guaranteed to
outlive the child's "struct device" (because the child holds a kobject
reference to the parent), the parent's "devm" allocated memory is a
different story. That appears to be freed much earlier.
Let's make this better for ti-sn65dsi86 by allocating each auxiliary
with kzalloc and then free that memory in the release().
Fixes: bf73537f41 ("drm/bridge: ti-sn65dsi86: Break GPIO and MIPI-to-eDP bridge into sub-drivers")
Suggested-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230613065812.v2.1.I24b838a5b4151fb32bccd6f36397998ea2df9fbb@changeid
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 102e80d1fa
("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 4fb912e5e1 ("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 c2d94f7214 ("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
Commit 5d844091f2 ("drm/scdc-helper: Pimp SCDC debugs") changed the scdc
interface to pick up an i2c adapter from a connector instead. However, in
the case of dw-hdmi, the wrong connector was being used to pass i2c adapter
information, since dw-hdmi's embedded connector structure is only populated
when the bridge attachment callback explicitly asks for it.
drm-meson is handling connector creation, so this won't happen, leading to
a NULL pointer dereference.
Fix it by having scdc functions access dw-hdmi's current connector pointer
instead, which is assigned during the bridge enablement stage.
Fixes: 5d844091f2 ("drm/scdc-helper: Pimp SCDC debugs")
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Reported-by: Lukas F. Hartmann <lukas@mntre.com>
Acked-by: Neil Armstrong <neil.armstrong@linaro.org>
[narmstrong: moved Fixes tag before first S-o-b and added Reported-by tag]
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230601123153.196867-1-adrian.larumbe@collabora.com
Before this patch, booting to Linux VT and doing a simple:
echo 2 > /sys/class/graphics/fb0/blank
echo 0 > /sys/class/graphics/fb0/blank
would result in failures to re-enable the panel. Mode set callback is
called only once during boot in this scenario, while calls to
enable/disable callbacks are balanced afterwards. The driver doesn't
work unless userspace calls modeset before enabling the CRTC/connector.
This patch moves enabling of the DSI host from mode_set into pre_enable
callback, and removes some old hacks where this bridge driver is
directly calling into other bridge driver's callbacks.
pre_enable_prev_first flag is set on the panel's bridge so that panel
drivers will get their prepare function called between DSI host's
pre_enable and enable callbacks, so that they get a chance to
perform panel setup while DSI host is already enabled in command
mode. Otherwise panel's prepare would be called before DSI host
is enabled, and any DSI communication used in prepare callback
would fail.
With all these changes, the enable/disable sequence is now well
balanced, and host's and panel's callbacks are called in proper order
documented in the drm_panel API documentation without needing the old
hacks. (Mainly that panel->prepare is called when DSI host is ready to
allow the panel driver to send DSI commands and vice versa during
disable.)
Tested on Pinephone Pro. Trace of the callbacks follows.
Before:
[ 1.253882] dw-mipi-dsi-rockchip ff960000.dsi: mode_set
[ 1.290732] panel-himax-hx8394 ff960000.dsi.0: prepare
[ 1.475576] dw-mipi-dsi-rockchip ff960000.dsi: enable
[ 1.475593] panel-himax-hx8394 ff960000.dsi.0: enable
echo 2 > /sys/class/graphics/fb0/blank
[ 13.722799] panel-himax-hx8394 ff960000.dsi.0: disable
[ 13.774502] dw-mipi-dsi-rockchip ff960000.dsi: post_disable
[ 13.774526] panel-himax-hx8394 ff960000.dsi.0: unprepare
echo 0 > /sys/class/graphics/fb0/blank
[ 17.735796] panel-himax-hx8394 ff960000.dsi.0: prepare
[ 17.923522] dw-mipi-dsi-rockchip ff960000.dsi: enable
[ 17.923540] panel-himax-hx8394 ff960000.dsi.0: enable
[ 17.944330] dw-mipi-dsi-rockchip ff960000.dsi: failed to write command FIFO
[ 17.944335] panel-himax-hx8394 ff960000.dsi.0: sending command 0xb9 failed: -110
[ 17.944340] panel-himax-hx8394 ff960000.dsi.0: Panel init sequence failed: -110
echo 2 > /sys/class/graphics/fb0/blank
[ 431.148583] panel-himax-hx8394 ff960000.dsi.0: disable
[ 431.169259] dw-mipi-dsi-rockchip ff960000.dsi: failed to write command FIFO
[ 431.169268] panel-himax-hx8394 ff960000.dsi.0: Failed to enter sleep mode: -110
[ 431.169282] dw-mipi-dsi-rockchip ff960000.dsi: post_disable
[ 431.169316] panel-himax-hx8394 ff960000.dsi.0: unprepare
[ 431.169357] pclk_mipi_dsi0 already disabled
echo 0 > /sys/class/graphics/fb0/blank
[ 432.796851] panel-himax-hx8394 ff960000.dsi.0: prepare
[ 432.981537] dw-mipi-dsi-rockchip ff960000.dsi: enable
[ 432.981568] panel-himax-hx8394 ff960000.dsi.0: enable
[ 433.002290] dw-mipi-dsi-rockchip ff960000.dsi: failed to write command FIFO
[ 433.002299] panel-himax-hx8394 ff960000.dsi.0: sending command 0xb9 failed: -110
[ 433.002312] panel-himax-hx8394 ff960000.dsi.0: Panel init sequence failed: -110
-----------------------------------------------------------------------
After:
[ 1.248372] dw-mipi-dsi-rockchip ff960000.dsi: mode_set
[ 1.248704] dw-mipi-dsi-rockchip ff960000.dsi: pre_enable
[ 1.285377] panel-himax-hx8394 ff960000.dsi.0: prepare
[ 1.468392] dw-mipi-dsi-rockchip ff960000.dsi: enable
[ 1.468421] panel-himax-hx8394 ff960000.dsi.0: enable
echo 2 > /sys/class/graphics/fb0/blank
[ 16.210357] panel-himax-hx8394 ff960000.dsi.0: disable
[ 16.261315] dw-mipi-dsi-rockchip ff960000.dsi: post_disable
[ 16.261339] panel-himax-hx8394 ff960000.dsi.0: unprepare
echo 0 > /sys/class/graphics/fb0/blank
[ 19.161453] dw-mipi-dsi-rockchip ff960000.dsi: pre_enable
[ 19.197869] panel-himax-hx8394 ff960000.dsi.0: prepare
[ 19.382141] dw-mipi-dsi-rockchip ff960000.dsi: enable
[ 19.382158] panel-himax-hx8394 ff960000.dsi.0: enable
(But depends on functionality intorduced in Linux 6.3, so this patch will
not build on older kernels when applied to older stable branches.)
Fixes: 46fc51546d ("drm/bridge/synopsys: Add MIPI DSI host controller bridge")
Signed-off-by: Ondrej Jirman <megi@xff.cz>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230617224915.1923630-1-megi@xff.cz
Move the register programming part, which actually enables the bridge and
makes it push data out of its DPI side, into the enable callback. The DSI
host like DSIM may not be able to transmit commands in pre_enable, moving
the register programming into enable assures it can transmit commands.
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230615201902.566182-1-marex@denx.de
Backmerging into drm-misc-next to get commit 2c1c7ba457
("drm/amdgpu: support partition drm devices"), which is required to fix
commit 0adec22702 ("drm: Remove struct drm_driver.gem_prime_mmap").
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
The high-speed clock is hard-coded to the burst-clock
frequency specified in the device tree. However, when
using devices like certain bridge chips without burst mode
and varying resolutions and refresh rates, it may be
necessary to set the high-speed clock dynamically based
on the desired pixel clock for the connected device.
This also removes the need to set a clock speed from
the device tree for non-burst mode operation, since the
pixel clock rate is the rate requested from the attached
device like a bridge chip. This should have no impact
for people using burst-mode and setting the burst clock
rate is still required for those users. If the burst
clock is not present, change the error message to
dev_info indicating the clock use the pixel clock.
Signed-off-by: Adam Ford <aford173@gmail.com>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Jagan Teki <jagan@amarulasolutions.com> # imx8mm-icore
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230526030559.326566-7-aford173@gmail.com
According to Table 13-45 of the i.MX8M Mini Reference Manual, the min
and max values for M and the frequency range for the VCO_out
calculator were incorrect. This information was contradicted in other
parts of the mini, nano and plus manuals. After reaching out to my
NXP Rep, when confronting him about discrepencies in the Nano manual,
he responded with:
"Yes it is definitely wrong, the one that is part
of the NOTE in MIPI_DPHY_M_PLLPMS register table against PMS_P,
PMS_M and PMS_S is not correct. I will report this to Doc team,
the one customer should be take into account is the Table 13-40
DPHY PLL Parameters and the Note above."
These updated values also match what is used in the NXP downstream
kernel.
To fix this, make new variables to hold the min and max values of m
and the minimum value of VCO_out, and update the PMS calculator to
use these new variables instead of using hard-coded values to keep
the backwards compatibility with other parts using this driver.
Fixes: 4d562c70c4 ("drm: bridge: samsung-dsim: Add i.MX8M Mini/Nano support")
Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Jagan Teki <jagan@amarulasolutions.com> # imx8mm-icore
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230526030559.326566-3-aford173@gmail.com
The datasheet describes the following initialization flow including
minimum delay times between each step:
1. DSI data lanes need to be in LP-11 and the clock lane in HS mode
2. toggle EN signal
3. initialize registers
4. enable PLL
5. soft reset
6. enable DSI stream
7. check error status register
To meet this requirement we need to make sure the host bridge's
pre_enable() is called first by using the pre_enable_prev_first
flag.
Furthermore we need to split enable() into pre_enable() which covers
steps 2-5 from above and enable() which covers step 7 and is called
after the host bridge's enable().
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Fixes: ceb515ba29 ("drm/bridge: ti-sn65dsi83: Add TI SN65DSI83 and SN65DSI84 driver")
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> #TQMa8MxML/MBa8Mx
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230503163313.2640898-3-frieder@fris.de
During probe, the driver registers i2c dummy devices and populates the
aux bus, which registers a device for the panel. After doing that, the
driver can still defer probe if needed. This ordering of operations is
troublesome however, because the deferred probe work will retry probing
all pending devices every time a new device is registered. Therefore, if
modules need to be loaded in order to satisfy the dependencies for this
driver to complete probe, the kernel will stall, since it'll keep trying
to probe the anx7625 driver, but never succeed, given that modules would
only be loaded after the deferred probe work completes.
Two changes are required to avoid this issue:
* Move of_find_mipi_dsi_host_by_node(), which can defer probe, to before
anx7625_register_i2c_dummy_clients() and
devm_of_dp_aux_populate_ep_devices(), which register devices.
* Make use of the done_probing callback when populating the aux bus,
so that the bridge registration is only done after the panel is
probed. This is required because the panel might need to defer probe,
but the aux bus population needs the i2c dummy devices working, so
this call couldn't just be moved to an earlier point in probe.
One caveat is that if the panel is described outside the aux bus, the
probe loop issue can still happen, but we don't have a way to avoid
it in that case since there's no callback available.
With this patch applied, it's possible to boot on
mt8192-asurada-spherion with
CONFIG_DRM_ANALOGIX_ANX7625=y
CONFIG_MTK_MMSYS=m
CONFIG_BACKLIGHT_PWM=y
and also with
CONFIG_DRM_ANALOGIX_ANX7625=y
CONFIG_MTK_MMSYS=y
CONFIG_BACKLIGHT_PWM=m
Fixes: adca62ec37 ("drm/bridge: anx7625: Support reading edid through aux channel")
Fixes: 269332997a ("drm/bridge: anx7625: Return -EPROBE_DEFER if the dsi host was not found")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230518193902.891121-1-nfraprado@collabora.com
Implement support for DSI clock and data lane DN/DP polarity swap by
means of decoding 'lane-polarities' DT property. The controller does
support DN/DP swap of clock lane and all data lanes, the controller
does not support polarity swap of individual data lane bundles, add
a check which verifies all data lanes have the same polarity.
This has been validated on an imx8mm board that actually has the MIPI DSI
clock lanes inverted.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230514114625.98372-2-festevam@gmail.com
There is no need to exclusively set the .owner member of the struct
device_driver when defining the platform_driver struct. The Linux core
takes care of setting the .owner member as part of the call to
module_platform_driver() helper function.
Issue identified using the platform_no_drv_owner.cocci Coccinelle
semantic patch as:
drivers/gpu/drm/bridge/samsung-dsim.c:1957:6-11: No need to set .owner here.
The core will do it.
No functional changes are intended.
Signed-off-by: Anup Sharma <anupnewsmail@gmail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/ZF9igb/nvL6GRBsq@yoga
Correct computation of THS_TRAILCNT register.
This register must be set to a value that ensure that
THS_TRAIL > 60 ns + 4 x UI
and
THS_TRAIL > 8 x UI
and
THS_TRAIL < TEOT
with
TEOT = 105 ns + (12 x UI)
with the actual value of THS_TRAIL being
(1 + THS_TRAILCNT) x ByteClk cycle + ((1 to 2) + 2) xHSBYTECLK cycle +
- (PHY output delay)
with PHY output delay being about
(8 + (5 to 6)) x MIPIBitClk cycle in the BitClk conversion.
Fixes: ff1ca6397b ("drm/bridge: Add tc358768 driver")
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230427142934.55435-9-francesco@dolcini.it
Correct computation of THS_ZEROCNT register.
This register must be set to a value that ensure that
THS_PREPARE + THS_ZERO > 145ns + 10*UI
with the actual value of (THS_PREPARE + THS_ZERO) being
((1 to 2) + 1 + (TCLK_ZEROCNT + 1) + (3 to 4)) x ByteClk cycle +
+ HSByteClk x (2 + (1 to 2)) + (PHY delay)
with PHY delay being about
(8 + (5 to 6)) x MIPIBitClk cycle in the BitClk conversion.
Fixes: ff1ca6397b ("drm/bridge: Add tc358768 driver")
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230427142934.55435-7-francesco@dolcini.it
Correct computation of TCLK_ZEROCNT register.
This register must be set to a value that ensure that
(TCLK-PREPARECNT + TCLK-ZERO) > 300ns
with the actual value of (TCLK-PREPARECNT + TCLK-ZERO) being
(1 to 2) + (TCLK_ZEROCNT + 1)) x HSByteClkCycle + (PHY output delay)
with PHY output delay being about
(2 to 3) x MIPIBitClk cycle in the BitClk conversion.
Fixes: ff1ca6397b ("drm/bridge: Add tc358768 driver")
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230427142934.55435-5-francesco@dolcini.it
Always enable HS video mode setting the TXMD bit, without this change no
video output is present with DSI sinks that are setting
MIPI_DSI_MODE_LPM flag (tested with LT8912B DSI-HDMI bridge).
Previously the driver was enabling HS mode only when the DSI sink was
not explicitly setting the MIPI_DSI_MODE_LPM, however this is not
correct.
The MIPI_DSI_MODE_LPM is supposed to indicate that the sink is willing
to receive data in low power mode, however clearing the
TC358768_DSI_CONTROL_TXMD bit will make the TC358768 send video in
LP mode that is not the intended behavior.
Fixes: ff1ca6397b ("drm/bridge: Add tc358768 driver")
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230427142934.55435-2-francesco@dolcini.it
