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Input: goodix - try not to touch the reset-pin on x86/ACPI devices

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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 921daeeca9 ("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: a7d4b17166 ("Input: goodix - add support for getting IRQ + reset GPIOs on Cherry Trail devices")
Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211206091116.44466-2-hdegoede@redhat.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Hans de Goede 2021-12-06 23:15:09 -08:00 committed by Dmitry Torokhov
parent 44ee250aee
commit a2fd46cd3d
2 changed files with 26 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
drivers/input/touchscreen/goodix.c
View File

@ -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)

1
drivers/input/touchscreen/goodix.h
View File

@ -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;