[PATCH regression fix 1/1] Input: goodix - Try not to touch the reset-pin on x86/ACPI devices
From: Hans de Goede <hidden>
Date: 2021-12-06 09:11:30
Subsystem:
goodix touchscreen, input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Hans de Goede, Dmitry Torokhov, Linus Torvalds
Unless the controller is not responding at boot or after suspend/resume,
the driver never resets the controller on x86/ACPI platforms. The driver
still requesting the reset pin at probe() though in case it needs it.
Until now the driver has always requested the reset pin with GPIOD_IN
as type. The idea being to put the pin in high-impedance mode to save
power until the driver actually wants to issue a reset.
But this means that just requesting the pin can cause issues, since
requesting it in another mode then GPIOD_ASIS may cause the pinctrl
driver to touch the pin settings. We have already had issues before
due to a bug in the pinctrl-cherryview.c driver which has been fixed in
commit 921daeeca91b ("pinctrl: cherryview: Preserve
CHV_PADCTRL1_INVRXTX_TXDATA flag on GPIOs").
And now it turns out that requesting the reset-pin as GPIOD_IN also stops
the touchscreen from working on the GPD P2 max mini-laptop. The behavior
of putting the pin in high-impedance mode relies on there being some
external pull-up to keep it high and there seems to be no pull-up on the
GPD P2 max, causing things to break.
This commit fixes this by requesting the reset pin as is when using
the x86/ACPI code paths to lookup the GPIOs; and by not dropping it
back into input-mode in case the driver does end up issuing a reset
for error-recovery.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=209061
Fixes: a7d4b171660c ("Input: goodix - add support for getting IRQ + reset GPIOs on Cherry Trail devices")
Signed-off-by: Hans de Goede <redacted>
---
drivers/input/touchscreen/goodix.c | 30 +++++++++++++++++++++++++-----
drivers/input/touchscreen/goodix.h | 1 +
2 files changed, 26 insertions(+), 5 deletions(-)
diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index b5cc91788195..eaa659969097 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c@@ -650,10 +650,16 @@ int goodix_reset_no_int_sync(struct goodix_ts_data *ts) usleep_range(6000, 10000); /* T4: > 5ms */ - /* end select I2C slave addr */ - error = gpiod_direction_input(ts->gpiod_rst); - if (error) - goto error; + /* + * Put the reset pin back in to input / high-impedance mode to save + * power. Only do this in the non ACPI case since some ACPI boards + * don't have a pull-up, so there the reset pin must stay active-high. + */ + if (ts->irq_pin_access_method == IRQ_PIN_ACCESS_GPIO) { + error = gpiod_direction_input(ts->gpiod_rst); + if (error) + goto error; + } return 0;
@@ -787,6 +793,14 @@ static int goodix_add_acpi_gpio_mappings(struct goodix_ts_data *ts) return -EINVAL; } + /* + * Normally we put the reset pin in input / high-impedance mode to save + * power. But some x86/ACPI boards don't have a pull-up, so for the ACPI + * case, leave the pin as is. This results in the pin not being touched + * at all on x86/ACPI boards, except when needed for error-recover. + */ + ts->gpiod_rst_flags = GPIOD_ASIS; + return devm_acpi_dev_add_driver_gpios(dev, gpio_mapping); } #else
@@ -812,6 +826,12 @@ static int goodix_get_gpio_config(struct goodix_ts_data *ts) return -EINVAL; dev = &ts->client->dev; + /* + * By default we request the reset pin as input, leaving it in + * high-impedance when not resetting the controller to save power. + */ + ts->gpiod_rst_flags = GPIOD_IN; + ts->avdd28 = devm_regulator_get(dev, "AVDD28"); if (IS_ERR(ts->avdd28)) { error = PTR_ERR(ts->avdd28);
@@ -849,7 +869,7 @@ static int goodix_get_gpio_config(struct goodix_ts_data *ts) ts->gpiod_int = gpiod; /* Get the reset line GPIO pin number */ - gpiod = devm_gpiod_get_optional(dev, GOODIX_GPIO_RST_NAME, GPIOD_IN); + gpiod = devm_gpiod_get_optional(dev, GOODIX_GPIO_RST_NAME, ts->gpiod_rst_flags); if (IS_ERR(gpiod)) { error = PTR_ERR(gpiod); if (error != -EPROBE_DEFER)
diff --git a/drivers/input/touchscreen/goodix.h b/drivers/input/touchscreen/goodix.h
index 62138f930d1a..02065d1c3263 100644
--- a/drivers/input/touchscreen/goodix.h
+++ b/drivers/input/touchscreen/goodix.h@@ -87,6 +87,7 @@ struct goodix_ts_data { struct gpio_desc *gpiod_rst; int gpio_count; int gpio_int_idx; + enum gpiod_flags gpiod_rst_flags; char id[GOODIX_ID_MAX_LEN + 1]; char cfg_name[64]; u16 version;
--
2.33.1