| Message ID | 20230426093231.1466984-3-fshao@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix Goodix touchscreen power leakage for MT8186 boards | expand |
Hi, On Wed, Apr 26, 2023 at 2:33 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 disable 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 v2: > - Do not change the regulator_enable logic during power-up. > > drivers/hid/i2c-hid/i2c-hid-of-goodix.c | 26 +++++++++++++++++++++++++ > 1 file changed, 26 insertions(+) > > diff --git a/drivers/hid/i2c-hid/i2c-hid-of-goodix.c b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c > index 0060e3dcd775..fc4532fcadcc 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 +38,20 @@ 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) { > + /* > + * This is not mandatory, but we assert reset 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. > + * > + * Note that in this case we assume the regulators should be > + * (marked as) always-on, so the regulator core knows what to > + * do with them in the following regulator_enable() calls > + * despite regulator_disable() was not called previously. > + */ > + gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); > + } > ret = regulator_enable(ihid_goodix->vdd); > if (ret) > return ret; > @@ -60,6 +75,14 @@ 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); > > + /* > + * Don't assert reset GPIO if it's set. > + * Also, it's okay to skip the following regulator_disable() calls > + * because the regulators should be always-on in this case. > + */ > + if (ihid_goodix->no_reset_during_suspend) > + return; > + > gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); > regulator_disable(ihid_goodix->vddio); > regulator_disable(ihid_goodix->vdd); I think the above is wrong. You should just skip the GPIO call when "no_reset_during_suspend", not the regulator calls. As your code is written, you'll enable the regulators over and over again in "power_up" and never in "power_down". -Doug
On Wed, Apr 26, 2023 at 10:05 PM Doug Anderson <dianders@chromium.org> wrote: > > Hi, > > On Wed, Apr 26, 2023 at 2:33 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 disable 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 v2: > > - Do not change the regulator_enable logic during power-up. > > > > drivers/hid/i2c-hid/i2c-hid-of-goodix.c | 26 +++++++++++++++++++++++++ > > 1 file changed, 26 insertions(+) > > > > diff --git a/drivers/hid/i2c-hid/i2c-hid-of-goodix.c b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c > > index 0060e3dcd775..fc4532fcadcc 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 +38,20 @@ 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) { > > + /* > > + * This is not mandatory, but we assert reset 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. > > + * > > + * Note that in this case we assume the regulators should be > > + * (marked as) always-on, so the regulator core knows what to > > + * do with them in the following regulator_enable() calls > > + * despite regulator_disable() was not called previously. > > + */ > > + gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); > > + } > > ret = regulator_enable(ihid_goodix->vdd); > > if (ret) > > return ret; > > @@ -60,6 +75,14 @@ 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); > > > > + /* > > + * Don't assert reset GPIO if it's set. > > + * Also, it's okay to skip the following regulator_disable() calls > > + * because the regulators should be always-on in this case. > > + */ > > + if (ihid_goodix->no_reset_during_suspend) > > + return; > > + > > gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); > > regulator_disable(ihid_goodix->vddio); > > regulator_disable(ihid_goodix->vdd); > > I think the above is wrong. You should just skip the GPIO call when > "no_reset_during_suspend", not the regulator calls. As your code is > written, you'll enable the regulators over and over again in > "power_up" and never in "power_down". Agree, I'll resend v3. Thanks for the feedback! Regards, Fei > > -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..fc4532fcadcc 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 +38,20 @@ 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) { + /* + * This is not mandatory, but we assert reset 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. + * + * Note that in this case we assume the regulators should be + * (marked as) always-on, so the regulator core knows what to + * do with them in the following regulator_enable() calls + * despite regulator_disable() was not called previously. + */ + gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); + } ret = regulator_enable(ihid_goodix->vdd); if (ret) return ret; @@ -60,6 +75,14 @@ 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); + /* + * Don't assert reset GPIO if it's set. + * Also, it's okay to skip the following regulator_disable() calls + * because the regulators should be always-on in this case. + */ + if (ihid_goodix->no_reset_during_suspend) + return; + gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1); regulator_disable(ihid_goodix->vddio); regulator_disable(ihid_goodix->vdd); @@ -91,6 +114,9 @@ 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 disable 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 v2: - Do not change the regulator_enable logic during power-up. drivers/hid/i2c-hid/i2c-hid-of-goodix.c | 26 +++++++++++++++++++++++++ 1 file changed, 26 insertions(+)