This is a note to let you know that I've just added the patch titled Input: goodix - try not to touch the reset-pin on x86/ACPI devices to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: input-goodix-try-not-to-touch-the-reset-pin-on-x86-a.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 737dfb405e507718ae739d0bf348f289e32d77dc Author: Hans de Goede <hdegoede@xxxxxxxxxx> Date: Mon Dec 6 23:15:09 2021 -0800 Input: goodix - try not to touch the reset-pin on x86/ACPI devices [ Upstream commit a2fd46cd3dbb83b373ba74f4043f8dae869c65f1 ] 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") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Link: https://lore.kernel.org/r/20211206091116.44466-2-hdegoede@xxxxxxxxxx Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c index 2ca903a8af21..3667f7e51fde 100644 --- a/drivers/input/touchscreen/goodix.c +++ b/drivers/input/touchscreen/goodix.c @@ -640,10 +640,16 @@ 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; @@ -777,6 +783,14 @@ 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 @@ -802,6 +816,12 @@ 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); @@ -839,7 +859,7 @@ 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 0b88554ba2ae..1a1571ad2cd2 100644 --- a/drivers/input/touchscreen/goodix.h +++ b/drivers/input/touchscreen/goodix.h @@ -51,6 +51,7 @@ 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]; u16 version; const char *cfg_name;