Hi,
On 3/6/20 5:03 AM, Dmitry Torokhov wrote:
Hi Hans,
On Thu, Mar 05, 2020 at 11:01:22PM +0100, Hans de Goede wrote:
Suspending Goodix touchscreens requires changing the interrupt pin to
output before sending them a power-down command. Followed by wiggling
the interrupt pin to wake the device up, after which it is put back
in input mode.
So far we have only effectively supported this on devices which use
devicetree. On X86 ACPI platforms both looking up the pins; and using a
pin as both IRQ and GPIO is a bit more complicated. E.g. on some devices
we cannot directly access the IRQ pin as GPIO and we need to call ACPI
methods to control it instead.
This commit adds a new irq_pin_access_method field to the goodix_chip_data
struct and adds goodix_irq_direction_output and goodix_irq_direction_input
helpers which together abstract the GPIO accesses to the IRQ pin.
This is a preparation patch for adding support for properly suspending the
touchscreen on X86 ACPI platforms.
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1786317
BugLink: https://github.com/nexus511/gpd-ubuntu-packages/issues/10
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199207
Cc: Dmitry Mastykin <mastichi@xxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
Changes in v2:
- Make enum member names upper-case
---
drivers/input/touchscreen/goodix.c | 62 ++++++++++++++++++++++++------
1 file changed, 51 insertions(+), 11 deletions(-)
diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index 0403102e807e..9cfbcf3cbca8 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -31,6 +31,11 @@
struct goodix_ts_data;
+enum goodix_irq_pin_access_method {
+ IRQ_PIN_ACCESS_NONE,
+ IRQ_PIN_ACCESS_GPIO,
+};
+
struct goodix_chip_data {
u16 config_addr;
int config_len;
@@ -53,6 +58,7 @@ struct goodix_ts_data {
const char *cfg_name;
struct completion firmware_loading_complete;
unsigned long irq_flags;
+ enum goodix_irq_pin_access_method irq_pin_access_method;
unsigned int contact_size;
};
@@ -502,17 +508,48 @@ static int goodix_send_cfg(struct goodix_ts_data *ts,
return 0;
}
+static int goodix_irq_direction_output(struct goodix_ts_data *ts,
+ int value)
+{
+ switch (ts->irq_pin_access_method) {
+ case IRQ_PIN_ACCESS_NONE:
+ dev_err(&ts->client->dev,
+ "%s called without an irq_pin_access_method set\n",
+ __func__);
+ return -EINVAL;
+ case IRQ_PIN_ACCESS_GPIO:
+ return gpiod_direction_output(ts->gpiod_int, value);
+ }
+
+ return -EINVAL; /* Never reached */
I do not like these "never reached" comments. We can either let compiler
issue a warning that we did not cover all switch cases, or stick
"default:" alongside "case IRQ_PIN_ACCESS_NONE:".
I just tried removing this line, this results in:
CC [M] drivers/input/touchscreen/goodix.o
drivers/input/touchscreen/goodix.c: In function ‘goodix_irq_direction_output’:
drivers/input/touchscreen/goodix.c:593:1: warning: control reaches end of non-void function [-Wreturn-type]
593 | }
| ^
And I do not want to add a default label, the switch-case is on an enum type and
if I do that I loose the useful warnings for one of the enum values not being
handled in the switch-case.
Regards,
Hans
