The code from [1] sets SYS_CTRL_1 to different values depending on the
desired clock phase (0, 1/4, 1/2 or 3/4). A clock phase of 0 aligns the
positive edge of the clock with the pixel data while other values delay
the clock by a fraction of the clock period. A clock phase of 1/2 aligns
the negative edge of the clock with the pixel data.
The driver currently hard codes SYS_CTRL_1 to 0x88 which corresponds to
aligning the positive edge of the clock with the pixel data. This won't
work correctly for panels that require aligning the negative edge of the
clock with the pixel data.
Adjust the clock phase to 0 if DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE is
present in bus_flags, otherwise adjust the clock phase to 1/2 as
appropriate for DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE.
[1] https://github.com/tdjastrzebski/ICN6211-Configurator
Signed-off-by: Jonathan Liu <net147@gmail.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220523130144.444225-1-net147@gmail.com
ADV7511_REG_CEC_RX_FRAME_HDR[] and ADV7511_REG_CEC_RX_FRAME_LEN[]
are only used inside adv7511_cec.c.
Move their definitions to this file to avoid the following build
warnings when CONFIG_DRM_I2C_ADV7511_CEC is not selected:
drivers/gpu/drm/bridge/adv7511/adv7511.h:229:17: warning: 'ADV7511_REG_CEC_RX_FRAME_HDR' defined but not used [-Wunused-const-variable=]
drivers/gpu/drm/bridge/adv7511/adv7511.h:235:17: warning: 'ADV7511_REG_CEC_RX_FRAME_LEN' defined but not used [-Wunused-const-variable=]
Reported-by: kernel test robot <lkp@intel.com>
Fixes: ab0af093bf ("drm: bridge: adv7511: use non-legacy mode for CEC RX")
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220525215316.1133057-1-festevam@gmail.com
If CONFIG_DRM_PANEL_SAMSUNG_ATNA33XC20=y && CONFIG_DRM_DISPLAY_HELPER=m,
bulding fails:
drivers/gpu/drm/panel/panel-samsung-atna33xc20.o: In function `atana33xc20_probe':
panel-samsung-atna33xc20.c:(.text+0x744): undefined reference to
`drm_panel_dp_aux_backlight'
make: *** [vmlinux] Error 1
Let CONFIG_DRM_PANEL_SAMSUNG_ATNA33XC20 select DRM_DISPLAY_DP_HELPER and
CONFIG_DRM_DISPLAY_HELPER to fix this error.
Fixes: 32ce3b3203 ("drm/panel: atna33xc20: Introduce the Samsung ATNA33XC20 panel")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Gao Chao <gaochao49@huawei.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220524024551.539-1-gaochao49@huawei.com
The SPI core always reports a "MODALIAS=spi:<foo>", even if the device was
registered via OF. This means that the st7735r.ko module won't autoload if
a DT has a node with a compatible "okaya,rh128128t" string.
In that case, kmod expects a "MODALIAS=of:N*T*Cokaya,rh128128t" uevent but
instead will get a "MODALIAS=spi:rh128128t", which is not present in the
list of aliases:
$ modinfo drivers/gpu/drm/tiny/st7735r.ko | grep alias
alias: of:N*T*Cokaya,rh128128tC*
alias: of:N*T*Cokaya,rh128128t
alias: of:N*T*Cjianda,jd-t18003-t01C*
alias: of:N*T*Cjianda,jd-t18003-t01
alias: spi:jd-t18003-t01
To workaround this issue, add in the SPI table an entry for that device.
Fixes: d1d511d516 ("drm: tiny: st7735r: Add support for Okaya RH128128T")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: David Lechner <david@lechnology.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220520091602.179078-1-javierm@redhat.com
When doing DP AUX transfers there are two actors that need to be
powered in order for the DP AUX transfer to work: the DP source and
the DP sink. Commit bacbab58f0 ("drm: Mention the power state
requirement on side-channel operations") added some documentation
saying that the DP source is required to power itself up (if needed)
to do AUX transfers. However, that commit doesn't talk anything about
the DP sink.
For full fledged DP the sink isn't really a problem. It's expected
that if an external DP monitor isn't plugged in that attempting to do
AUX transfers won't work. It's also expected that if a DP monitor is
plugged in (and thus asserting HPD) then AUX transfers will work.
When we're looking at eDP, however, things are less obvious. Let's add
some documentation about expectations. Here's what we'll say:
1. We don't expect the DP AUX transfer function to power on an eDP
panel. If an eDP panel is physically connected but powered off then it
makes sense for the transfer to fail.
2. We'll document that the official way to power on a panel is via the
bridge chain, specifically by making sure that the panel's prepare
function has been called (which is called by
panel_bridge_pre_enable()). It's already specified in the kernel doc
of drm_panel_prepare() that this is the way to power the panel on and
also that after this call "it is possible to communicate with any
integrated circuitry via a command bus."
3. We'll also document that for code running in the panel driver
itself that it is legal for the panel driver to power itself up
however it wants (it doesn't need to officially call
drm_panel_pre_enable()) and then it can do AUX bus transfers. This is
currently the way that edp-panel works when it's running atop the DP
AUX bus.
NOTE: there was much discussion of all of this in response to v1 [1]
of this patch. A summary of that is:
* With the Intel i195 driver, apparently eDP panels do get powered
up. We won't forbid this but it is expected that code that wants to
run on a variety of platforms should ensure that the drm_panel's
prepare() function has been called.
* There is at least a reasonable amount of agreement that the
transfer() functions itself shouldn't be responsible for powering
the panel. It's proposed that if we need the DP AUX dev nodes to be
robust for eDP that the code handling the DP AUX dev nodes could
handle powering the panel by ensuring that the panel's prepare()
call was made. Potentially drm_dp_aux_dev_get_by_minor() could be a
good place to do this. This is left as a future exercise. Until
that's fixed the DP AUX dev nodes for eDP are probably best just
used for debugging.
* If a panel could be in PSR and DP AUX via the dev node needs to be
reliable then we need to be able to pull the panel out of PSR. On
i915 this is also apparently handled as part of the transfer()
function.
[1] https://lore.kernel.org/r/20220503162033.1.Ia8651894026707e4fa61267da944ff739610d180@changeid
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220509161733.v2.1.Ia8651894026707e4fa61267da944ff739610d180@changeid
As per Displayport spec section 5.2.1.2 ("Video Timing Format") says
that all detachable sinks shall support 640x480 @60Hz as a fail safe
mode.
A DP compliance test expected us to utilize the above fact when all
modes it presented to the DP source were not achievable. It presented
only modes that would be achievable with more lanes and/or higher
speeds than we had available and expected that when we couldn't do
that then we'd fall back to 640x480 even though it didn't advertise
this size.
In order to pass the compliance test (and also support any users who
might fall into a similar situation with their display), we need to
add 640x480 into the list of modes. However, we don't want to add
640x480 all the time. Despite the fact that the DP spec says all sinks
_shall support_ 640x480, they're not guaranteed to support it
_well_. Continuing to read the spec you can see that the display is
not required to really treat 640x480 equal to all the other modes. It
doesn't need to scale or anything--just display the pixels somehow for
failsafe purposes. It should also be noted that it's not hard to find
a display hooked up via DisplayPort that _doesn't_ support 640x480 at
all. The HP ZR30w screen I'm sitting in front of has a native DP port
and doesn't work at 640x480. I also plugged in a tiny 800x480 HDMI
display via a DP to HDMI adapter and that screen definitely doesn't
support 640x480.
As a compromise solution, let's only add the 640x480 mode if:
* We're on DP.
* All other modes have been pruned.
This acknowledges that 640x480 might not be the best mode to use but,
since sinks are _supposed_ to support it, we will at least fall back
to it if there's nothing else.
Note that we _don't_ add higher resolution modes like 1024x768 in this
case. We only add those modes for a failed EDID read where we have no
idea what's going on. In the case where we've pruned all modes then
instead we only want 640x480 which is the only defined "Fail Safe"
resolution.
This patch originated in response to Kuogee Hsieh's patch [1].
[1] https://lore.kernel.org/r/1650671124-14030-1-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220511155749.v3.2.I4ac7f55aa446699f8c200a23c10463256f6f439f@changeid
Split up the connector's mode_valid helper into a simple-pipe and a
mode-config helper. The simple-pipe helper tests for display-size
limits while the mode-config helper tests for memory-bandwidth limits.
Also add the mgag200_ prefix to mga_vga_calculate_mode_bandwidth() and
comment on the function's purpose.
The memory-bandwidth tests assume that the display uses 4 bytes per
pixel. The first models of G200SE-A only had 1.75 MiB of VRAM, which
limits these devices to 640x480-32.
v2:
* note the memory constraints on early G200SE-A
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Tested-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220516134343.6085-8-tzimmermann@suse.de
Test for a mode's memory requirements in the device-wide mode_valid
helper. For simplicify, always assume a 32-bit color format. While
some rejected modes would work with less colors, implementing this
is probably not worth the effort.
Also remove the memory-related test from the connector's mode_valid
helper. The test uses the bpp value that users can specify on the
kernel's command line. This value is unrelated and the test would
belong into atomic_check.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Tested-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220516134343.6085-7-tzimmermann@suse.de
Initialization of the I2C adapter was allowed to fail. The mgag200
driver would have continued without DDC support. Had this happened in
practice, it would have led to segmentation faults in the connector
code. Resolve this problem by failing driver initialization on I2C-
related errors.
v2:
* initialize 'ret' before drm_err() (kernel test robot)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Tested-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220516134343.6085-3-tzimmermann@suse.de
