As discussed in the patch ("dt-bindings: drm/panel-simple: Introduce
generic eDP panels") we can actually support probing eDP panels at
runtime instead of hardcoding what panel is connected. Add support to
the panel-edp driver for this.
We'll implement a solution like this:
* We'll read in two delays from the device tree that are used for
powering up the panel the initial time (to read the EDID).
* In the EDID we can find a 32-bit ID that identifies what panel we've
found. From this ID we can look up the full set of delays.
After this change we'll still need to add per-panel delays into the
panel-simple driver but we will no longer need to specify exactly
which panel is connected to which board in the device tree. Nicely,
any panels that are only supported this way also don't need to
hardcode mode data since it's guaranteed that we can get that through
the EDID.
This patch will seed the ID-to-delay table with a few panels that I
have access to, many of which are on sc7180-trogdor devices.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.15.Id9c96cba4eba3e5ee519bfb09cd64b39f2490293@changeid
While cleaning up the descriptions of the delay for eDP panels I
realized that we'd have a bug if any panels need the
"prepare_to_enable" but HPD handling isn't happening in the panel
driver. Let's put in a stopgap to at least make us not violate
timings. This is not perfectly optimal but trying to do better is
hard. At the moment only 2 panels specify this delay and only 30 ms is
at stake. These panels are also currently hooked up with "hpd-gpios"
so effectively this "fix" is just a theoretical fix and won't actually
do anything for any devices currently supported in mainline.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.13.Ia8288d36df4b12770af59ae3ff73ef7e08fb4e2e@changeid
Now that the eDP panel driver only handles eDP panels we can make
better sense of the delays here. Let's describe them in terms of the
standard eDP timing diagram from the eDP spec.
As part of this, it becomes pretty clear that some eDP panels have too
long of a "hpd_reliable_delay". This used to be the "prepare"
delay. It's the fixed delay that we do in the panel driver after
powering on our panel before we look at the HPD signal. To understand
this better, first realize that there could be 3 paths we follow
depending on how HPD is hooked up. Let's walk through them:
1. HPD is handled by the eDP controller driver. Until "recently"
(commit 48834e6084 ("drm/panel-simple: Support hpd-gpios for
delaying prepare()") in May 2020) this was the only supported
way. This is supposed to be when the controller driver gets HPD
straight to a dedicated pin. In this case the controller driver
should be waiting for HPD in its pre_enable() routine which should
be called right after the panel's prepare() function is
called. That means that the old "prepare" delay was only needed as
a delay after powering the panel but before looking at HPD.
2. HPD is handled via hpd-gpios in the panel. This is much like #1 but
much easier to follow since all the handling is in the panel
driver.
3. The no-hpd case. This is also easy to follow.
In any case, even though it seems like some old panel data was using
this incorrectly, let's not touch the old data structures but we'll
add a note indicating that something seems off.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.11.I2d798dd015332661c5895ef744bc8ec5cd2e06ca@changeid
Not all panels in panel-simple were marked what type of panel they
were. I searched through ARM/ARM64 Chromebooks or Chromebook-related
reference boards that I was aware of and found some panels that needed
to be moved. I also skimmed for panels that had no mode and were "big"
since it's quite rare to see a small eDP panel. Here's what I found:
* auo,b101ean01 - rk3288-veyron-minnie
* auo,b133htn01 - exynos5800-peach-pi
* auo,b133xtn01 - tegra124-nyan-big
* boe,nv101wxmn51 - rk3399-gru-bob
* innolux,p120zdg-bf1 - sdm845-cheza
* lg,lp079qx1-sp0v - rk3399-evb and similar
* lg,lp097qx1-spa1 - According to commit 0355dde26e ("drm/panel:
simple: Add support for LG LP097QX1-SPA1 panel") this is an eDP
panel.
* lg,lp129qe - tegra124-venice2
* samsung,lsn122dl01-c01 - According to commit 0330eaf390
("drm/panel: simple: Add support for Samsung LSN122DL01-C01 panel")
this is an eDP panel.
* samsung,ltn140at29-301 - tegra124-nyan-blaze
* sharp,ld-d5116z01b - According to commit cd5e1cbe1f ("drm/panel:
simple: Add support for Sharp LD-D5116Z01B panel") this is an eDP
panel.
* sharp,lq123p1jx31 - rk3399-gru-kevin
* starry,kr122ea0sra - rk3399-gru-gru (reference board, not upstream)
I won't promise that I didn't miss a single panel, but that's fairly
complete I think.
I'm not sure the full impact of the fact that they didn't have the
connector type specified, but at least as of commit 9f069c6fbc
("drm/panel: panel-simple: add default connector_type") we may have
been accidentally thinking of them as DPI panels. We also would
certainly have had a warning. In any case since we don't want to
support anything eDP in the old simple-panel driver, we should move
these.
Cc: Yakir Yang <ykk@rock-chips.com>
Cc: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.8.I84e36f9f86d5d693fce0641a55ddb264a518a947@changeid
The panel-simple driver handles way too much. Let's start trying to
get a handle on it by splitting out the eDP panels. This patch does
this:
1. Start by copying simple-panel verbatim over to a new driver,
simple-panel-edp.
2. Rename "panel_simple" to "panel_edp" in the new driver.
3. Keep only panels marked with `DRM_MODE_CONNECTOR_eDP` in the new
driver. Remove those panels from the old driver.
4. Remove all recent "DP AUX bus" stuff from the old driver. The DP
AUX bus is only possible on DP panels.
5. Remove all DSI / MIPI related functions from the new driver.
6. Remove bus_format / bus_flags from eDP driver. These things don't
seem to make any sense for eDP panels so let's stop filling in made
up stuff.
In the end we end up with a bunch of duplicated code for now. Future
patches will try to address _some_ of this duplicated code though some
of it will be unavoidable.
NOTE: This may not actually move all eDP panels over to the new driver
since not all panels were properly marked with
`DRM_MODE_CONNECTOR_eDP`. A future patch will attempt to move wayward
panels I could identify but even so there may be some missed.
Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.7.I0a2f75bb822d17ce06f5b147734764eeb0c3e3df@changeid
