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HID: i2c-hid: goodix: Add support for "goodix,no-reset-during-suspend" property

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[ Upstream commit 7607f12ba7 ]

In the beginning, commit 18eeef46d3 ("HID: i2c-hid: goodix: Tie the
reset line to true state of the regulator") introduced a change to tie
the reset line of the Goodix touchscreen to the state of the regulator
to fix a power leakage issue in suspend.

After some time, the change was deemed unnecessary and was reverted in
commit 557e05fa9f ("HID: i2c-hid: goodix: Stop tying the reset line to
the regulator") due to difficulties in managing regulator notifiers for
designs like Evoker, which provides a second power rail to touchscreen.

However, the revert caused a power regression on another Chromebook
device Steelix in the field, which has a dedicated always-on regulator
for touchscreen and was covered by the workaround in the first commit.

To address both cases, this patch adds the support for the new
"goodix,no-reset-during-suspend" property in the driver:
- When set to true, the driver does not assert the reset GPIO during
  power-down.
  Instead, the GPIO will be asserted during power-up to ensure the
  touchscreen always has a clean start and consistent behavior after
  resuming.
  This is for designs with a dedicated always-on regulator.
- When set to false or unset, the driver uses the original control flow
  and asserts GPIO and disables regulators normally.
  This is for the two-regulator and shared-regulator designs.

Signed-off-by: Fei Shao <fshao@chromium.org>
Suggested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Jeff LaBundy <jeff@labundy.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Fei Shao 2023-05-24 11:42:37 +08:00 • committed by Greg Kroah-Hartman
commit cfe5e5d87e
1 changed files with 15 additions and 1 deletions
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