| Message ID | 20230426144423.2820826-3-fshao@chromium.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Fix Goodix touchscreen power leakage for MT8186 boards | expand |
Hi, On Wed, Apr 26, 2023 at 7:44 AM Fei Shao <fshao@chromium.org> wrote: > > In the beginning, commit 18eeef46d359 ("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 557e05fa9fdd ("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> > Reviewed-by: Douglas Anderson <dianders@chromium.org> > > --- > > Changes in v3: > - In power-down, only skip the GPIO but not the regulator calls if the > flag is set > > Changes in v2: > - Do not change the regulator_enable logic during power-up. > > drivers/hid/i2c-hid/i2c-hid-of-goodix.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) You already carried over my Reviewed-by tag, which is fine. ...but just sending a quick confirmation that v3 looks good to me. Thanks! -Doug
diff --git a/drivers/hid/i2c-hid/i2c-hid-of-goodix.c b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c index 0060e3dcd775..3ed365b50432 100644 --- a/drivers/hid/i2c-hid/i2c-hid-of-goodix.c +++ b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c @@ -28,6 +28,7 @@ struct i2c_hid_of_goodix { struct regulator *vdd; struct regulator *vddio; struct gpio_desc *reset_gpio; + bool no_reset_during_suspend; const struct goodix_i2c_hid_timing_data *timings; }; @@ -37,6 +38,14 @@ static int goodix_i2c_hid_power_up(struct i2chid_ops *ops) container_of(ops, struct i2c_hid_of_goodix, ops); int ret; + if (ihid_goodix->no_reset_during_suspend) { + /* + * We assert reset GPIO here (instead of during power-down) to + * ensure the device will have a clean state after powering up, + * just like the normal scenarios will have. + */ + gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); + } ret = regulator_enable(ihid_goodix->vdd); if (ret) return ret; @@ -60,7 +69,9 @@ static void goodix_i2c_hid_power_down(struct i2chid_ops *ops) struct i2c_hid_of_goodix *ihid_goodix = container_of(ops, struct i2c_hid_of_goodix, ops); - gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); + if (!ihid_goodix->no_reset_during_suspend) + gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); + regulator_disable(ihid_goodix->vddio); regulator_disable(ihid_goodix->vdd); } @@ -91,6 +102,9 @@ static int i2c_hid_of_goodix_probe(struct i2c_client *client) if (IS_ERR(ihid_goodix->vddio)) return PTR_ERR(ihid_goodix->vddio); + ihid_goodix->no_reset_during_suspend = + of_property_read_bool(client->dev.of_node, "goodix,no-reset-during-suspend"); + ihid_goodix->timings = device_get_match_data(&client->dev); return i2c_hid_core_probe(client, &ihid_goodix->ops, 0x0001, 0);
In the beginning, commit 18eeef46d359 ("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 557e05fa9fdd ("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> Reviewed-by: Douglas Anderson <dianders@chromium.org> --- Changes in v3: - In power-down, only skip the GPIO but not the regulator calls if the flag is set Changes in v2: - Do not change the regulator_enable logic during power-up. drivers/hid/i2c-hid/i2c-hid-of-goodix.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)