From a2fd46cd3dbb83b373ba74f4043f8dae869c65f1 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Mon, 6 Dec 2021 23:15:09 -0800 Subject: Input: goodix - try not to touch the reset-pin on x86/ACPI devices 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@vger.kernel.org Signed-off-by: Hans de Goede Link: https://lore.kernel.org/r/20211206091116.44466-2-hdegoede@redhat.com Signed-off-by: Dmitry Torokhov --- 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 906b5a6b52d1..e7efc32043e7 100644 --- a/drivers/input/touchscreen/goodix.c +++ b/drivers/input/touchscreen/goodix.c @@ -695,10 +695,16 @@ 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; @@ -832,6 +838,14 @@ 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 @@ -857,6 +871,12 @@ 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); @@ -894,7 +914,7 @@ retry_get_irq_gpio: 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; -- cgit