Input: goodix - add support for polling mode

There are designs incorporating Goodix touch controller that do not
connect interrupt pin, for example Raspberry Pi. To support such systems
use polling mode for the input device when I2C client does not have
interrupt assigned to it.

Signed-off-by: Joseph Guo <qijian.guo@nxp.com>
Reviewed-by: Haibo Chen <haibo.chen@nxp.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20250522020418.1963422-1-qijian.guo@nxp.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Author: Joseph-Guo-nxp

drivers/input/touchscreen/goodix.c

@@ -44,9 +44,11 @@
 #define GOODIX_HAVE_KEY			BIT(4)
 #define GOODIX_BUFFER_STATUS_TIMEOUT	20
 
-#define RESOLUTION_LOC		1
-#define MAX_CONTACTS_LOC	5
-#define TRIGGER_LOC		6
+#define RESOLUTION_LOC			1
+#define MAX_CONTACTS_LOC		5
+#define TRIGGER_LOC			6
+
+#define GOODIX_POLL_INTERVAL_MS		17	/* 17ms = 60fps */
 
 /* Our special handling for GPIO accesses through ACPI is x86 specific */
 #if defined CONFIG_X86 && defined CONFIG_ACPI
@@ -497,6 +499,14 @@ static void goodix_process_events(struct goodix_ts_data *ts)
 	input_sync(ts->input_dev);
 }
 
+static void goodix_ts_work_i2c_poll(struct input_dev *input)
+{
+	struct goodix_ts_data *ts = input_get_drvdata(input);
+
+	goodix_process_events(ts);
+	goodix_i2c_write_u8(ts->client, GOODIX_READ_COOR_ADDR, 0);
+}
+
 /**
  * goodix_ts_irq_handler - The IRQ handler
  *
@@ -513,13 +523,29 @@ static irqreturn_t goodix_ts_irq_handler(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static void goodix_enable_irq(struct goodix_ts_data *ts)
+{
+	if (ts->client->irq)
+		enable_irq(ts->client->irq);
+}
+
+static void goodix_disable_irq(struct goodix_ts_data *ts)
+{
+	if (ts->client->irq)
+		disable_irq(ts->client->irq);
+}
+
 static void goodix_free_irq(struct goodix_ts_data *ts)
 {
-	devm_free_irq(&ts->client->dev, ts->client->irq, ts);
+	if (ts->client->irq)
+		devm_free_irq(&ts->client->dev, ts->client->irq, ts);
 }
 
 static int goodix_request_irq(struct goodix_ts_data *ts)
 {
+	if (!ts->client->irq)
+		return 0;
+
 	return devm_request_threaded_irq(&ts->client->dev, ts->client->irq,
 					 NULL, goodix_ts_irq_handler,
 					 ts->irq_flags, ts->client->name, ts);
@@ -1219,6 +1245,18 @@ static int goodix_configure_dev(struct goodix_ts_data *ts)
 		return error;
 	}
 
+	input_set_drvdata(ts->input_dev, ts);
+
+	if (!ts->client->irq) {
+		error = input_setup_polling(ts->input_dev, goodix_ts_work_i2c_poll);
+		if (error) {
+			dev_err(&ts->client->dev,
+				 "could not set up polling mode, %d\n", error);
+			return error;
+		}
+		input_set_poll_interval(ts->input_dev, GOODIX_POLL_INTERVAL_MS);
+	}
+
 	error = input_register_device(ts->input_dev);
 	if (error) {
 		dev_err(&ts->client->dev,
@@ -1422,7 +1460,7 @@ static int goodix_suspend(struct device *dev)
 
 	/* We need gpio pins to suspend/resume */
 	if (ts->irq_pin_access_method == IRQ_PIN_ACCESS_NONE) {
-		disable_irq(client->irq);
+		goodix_disable_irq(ts);
 		return 0;
 	}
 
@@ -1466,7 +1504,7 @@ static int goodix_resume(struct device *dev)
 	int error;
 
 	if (ts->irq_pin_access_method == IRQ_PIN_ACCESS_NONE) {
-		enable_irq(client->irq);
+		goodix_enable_irq(ts);
 		return 0;
 	}