Input: goodix - add support for controlling the IRQ pin through ACPI methods

Some Apollo Lake (x86, UEFI + ACPI) devices only list the reset GPIO
in their _CRS table and the bit-banging of the IRQ line necessary to
wake-up the controller from suspend can be done by calling 2 Goodix
custom / specific ACPI methods.

This commit adds support for controlling the IRQ line in this matter,
allowing us to properly suspend the touchscreen controller on such
devices.

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
Reviewed-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20200307121505.3707-6-hdegoede@redhat.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index 37862f7dfde3..8e31b4bc6275 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -35,6 +35,7 @@ enum goodix_irq_pin_access_method {
 	IRQ_PIN_ACCESS_NONE,
 	IRQ_PIN_ACCESS_GPIO,
 	IRQ_PIN_ACCESS_ACPI_GPIO,
+	IRQ_PIN_ACCESS_ACPI_METHOD,
 };
 
 struct goodix_chip_data {
@@ -532,6 +533,9 @@ static int goodix_send_cfg(struct goodix_ts_data *ts,
 static int goodix_irq_direction_output(struct goodix_ts_data *ts,
 				       int value)
 {
+	struct device *dev = &ts->client->dev;
+	acpi_status status;
+
 	switch (ts->irq_pin_access_method) {
 	case IRQ_PIN_ACCESS_NONE:
 		dev_err(&ts->client->dev,
@@ -546,6 +550,10 @@ static int goodix_irq_direction_output(struct goodix_ts_data *ts,
 		 * as active-low, use output_raw to avoid the value inversion.
 		 */
 		return gpiod_direction_output_raw(ts->gpiod_int, value);
+	case IRQ_PIN_ACCESS_ACPI_METHOD:
+		status = acpi_execute_simple_method(ACPI_HANDLE(dev),
+						    "INTO", value);
+		return ACPI_SUCCESS(status) ? 0 : -EIO;
 	}
 
 	return -EINVAL; /* Never reached */
@@ -553,6 +561,9 @@ static int goodix_irq_direction_output(struct goodix_ts_data *ts,
 
 static int goodix_irq_direction_input(struct goodix_ts_data *ts)
 {
+	struct device *dev = &ts->client->dev;
+	acpi_status status;
+
 	switch (ts->irq_pin_access_method) {
 	case IRQ_PIN_ACCESS_NONE:
 		dev_err(&ts->client->dev,
@@ -562,6 +573,10 @@ static int goodix_irq_direction_input(struct goodix_ts_data *ts)
 	case IRQ_PIN_ACCESS_GPIO:
 	case IRQ_PIN_ACCESS_ACPI_GPIO:
 		return gpiod_direction_input(ts->gpiod_int);
+	case IRQ_PIN_ACCESS_ACPI_METHOD:
+		status = acpi_evaluate_object(ACPI_HANDLE(dev), "INTI",
+					      NULL, NULL);
+		return ACPI_SUCCESS(status) ? 0 : -EIO;
 	}
 
 	return -EINVAL; /* Never reached */
@@ -656,6 +671,11 @@ static const struct acpi_gpio_mapping acpi_goodix_int_last_gpios[] = {
 	{ },
 };
 
+static const struct acpi_gpio_mapping acpi_goodix_reset_only_gpios[] = {
+	{ GOODIX_GPIO_RST_NAME "-gpios", &first_gpio, 1 },
+	{ },
+};
+
 static int goodix_resource(struct acpi_resource *ares, void *data)
 {
 	struct goodix_ts_data *ts = data;
@@ -713,6 +733,12 @@ static int goodix_add_acpi_gpio_mappings(struct goodix_ts_data *ts)
 	} else if (ts->gpio_count == 2 && ts->gpio_int_idx == 1) {
 		ts->irq_pin_access_method = IRQ_PIN_ACCESS_ACPI_GPIO;
 		gpio_mapping = acpi_goodix_int_last_gpios;
+	} else if (ts->gpio_count == 1 && ts->gpio_int_idx == -1 &&
+		   acpi_has_method(ACPI_HANDLE(dev), "INTI") &&
+		   acpi_has_method(ACPI_HANDLE(dev), "INTO")) {
+		dev_info(dev, "Using ACPI INTI and INTO methods for IRQ pin access\n");
+		ts->irq_pin_access_method = IRQ_PIN_ACCESS_ACPI_METHOD;
+		gpio_mapping = acpi_goodix_reset_only_gpios;
 	} else if (is_byt() && ts->gpio_count == 2 && ts->gpio_int_idx == -1) {
 		dev_info(dev, "No ACPI GpioInt resource, assuming that the GPIO order is reset, int\n");
 		ts->irq_pin_access_method = IRQ_PIN_ACCESS_ACPI_GPIO;
@@ -809,6 +835,10 @@ retry_get_irq_gpio:
 		if (!ts->gpiod_int || !ts->gpiod_rst)
 			ts->irq_pin_access_method = IRQ_PIN_ACCESS_NONE;
 		break;
+	case IRQ_PIN_ACCESS_ACPI_METHOD:
+		if (!ts->gpiod_rst)
+			ts->irq_pin_access_method = IRQ_PIN_ACCESS_NONE;
+		break;
 	default:
 		if (ts->gpiod_int && ts->gpiod_rst) {
 			ts->reset_controller_at_probe = true;