| Message ID | 20230523193017.4109557-1-dianders@chromium.org |
|---|---|
| Headers | show |
| Series | drm/panel and i2c-hid: Allow panels and touchscreens to power sequence together | expand |
Hi, On Tue, May 30, 2023 at 8:34 AM Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote: > > On 23/05/2023 21:27, Douglas Anderson wrote: > > As talked about in the patch ("drm/panel: Add a way for other devices > > to follow panel state"), touchscreens that are connected to panels are > > generally expected to be power sequenced together with the panel > > they're attached to. Today, nothing provides information allowing you > > to find out that a touchscreen is connected to a panel. Let's add a > > phandle for this. > > > > Signed-off-by: Douglas Anderson <dianders@chromium.org> > > --- > > > > Documentation/devicetree/bindings/input/elan,ekth6915.yaml | 6 ++++++ > > Documentation/devicetree/bindings/input/goodix,gt7375p.yaml | 6 ++++++ > > Documentation/devicetree/bindings/input/hid-over-i2c.yaml | 6 ++++++ > > 3 files changed, 18 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/input/elan,ekth6915.yaml b/Documentation/devicetree/bindings/input/elan,ekth6915.yaml > > index 05e6f2df604c..d55b03bd3ec4 100644 > > --- a/Documentation/devicetree/bindings/input/elan,ekth6915.yaml > > +++ b/Documentation/devicetree/bindings/input/elan,ekth6915.yaml > > @@ -24,6 +24,12 @@ properties: > > interrupts: > > maxItems: 1 > > > > + panel: > > + description: If this is a touchscreen, the panel it's connected to. This > > Hm, can there be different setup? Touchscreen without panel? What would > it be then? For a touchscreen that's a discrete device (not sharing logic / power rails with the panel) you'd just leave off the panel node like we've always done. Assuming folks like this series in general, I'll try to improve the wording for v2. > Why only these touchscreens? This looks generic, so maybe in > touchscreen.yaml? Ah, that makes sense. I guess we need to add an include of that file from the elan and goodix bindings. The hid-over-i2c.yaml already has it, though. I'm not 100% sure the existing "hid-over-i2c" driver in Linux actually calls the function to parse all those properties, but I guess that's a Linux problem and not a DT bindings problem. ;-) -Doug
The big motivation for this patch series is mostly described in the patch ("drm/panel: Add a way for other devices to follow panel state"), but to quickly summarize here: for touchscreens that are connected to a panel we need the ability to power sequence the two device together. This is not a new need, but so far we've managed to get by through a combination of inefficiency, added costs, or perhaps just a little bit of brokenness. It's time to do better. This patch series allows us to do better. Assuming that people think this patch series looks OK, we'll have to figure out the right way to land it. The panel patches and i2c-hid patches will go through very different trees and so either we'll need an Ack from one side or the other or someone to create a tag for the other tree to pull in. This will _probably_ require the true drm-misc maintainers to get involved, not a lowly committer. ;-) Douglas Anderson (9): dt-bindings: HID: i2c-hid: Add "panel" property to i2c-hid backed panels drm/panel: Check for already prepared/enabled in drm_panel drm/panel: Add a way for other devices to follow panel state HID: i2c-hid: Switch to SYSTEM_SLEEP_PM_OPS() HID: i2c-hid: Rearrange probe() to power things up later HID: i2c-hid: Make suspend and resume into helper functions HID: i2c-hid: Support being a panel follower HID: i2c-hid: Do panel follower work on the system_wq arm64: dts: qcom: sc7180: Link trogdor touchscreens to the panels .../bindings/input/elan,ekth6915.yaml | 6 + .../bindings/input/goodix,gt7375p.yaml | 6 + .../bindings/input/hid-over-i2c.yaml | 6 + .../boot/dts/qcom/sc7180-trogdor-coachz.dtsi | 1 + .../dts/qcom/sc7180-trogdor-homestar.dtsi | 1 + .../boot/dts/qcom/sc7180-trogdor-lazor.dtsi | 1 + .../boot/dts/qcom/sc7180-trogdor-pompom.dtsi | 1 + .../qcom/sc7180-trogdor-quackingstick.dtsi | 1 + .../dts/qcom/sc7180-trogdor-wormdingler.dtsi | 1 + drivers/gpu/drm/drm_panel.c | 194 +++++++++- drivers/hid/i2c-hid/i2c-hid-core.c | 330 +++++++++++++----- include/drm/drm_panel.h | 89 +++++ 12 files changed, 542 insertions(+), 95 deletions(-)