From f77bf2a13f6e8182e5e2f780fefb927160eebf20 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Mon, 30 Jan 2023 14:46:16 +0000
Subject: [PATCH] input: goodix: Add option to poll instead of relying on IRQ
 line

The interrupt line from the touch controller is not necessarily
connected to the SoC, so add the option to poll for touch info.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
 drivers/input/touchscreen/goodix.c | 70 ++++++++++++++++++++++++++++++++++----
 drivers/input/touchscreen/goodix.h |  2 ++
 2 files changed, 66 insertions(+), 6 deletions(-)

diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index af32fbe..93d24ab 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -48,6 +48,8 @@
 #define MAX_CONTACTS_LOC	5
 #define TRIGGER_LOC		6
 
+#define POLL_INTERVAL_MS		17	/* 17ms = 60fps */
+
 /* Our special handling for GPIO accesses through ACPI is x86 specific */
 #if defined CONFIG_X86 && defined CONFIG_ACPI
 #define ACPI_GPIO_SUPPORT
@@ -513,16 +515,67 @@ static irqreturn_t goodix_ts_irq_handler(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static void goodix_ts_irq_poll_timer(struct timer_list *t)
+{
+	struct goodix_ts_data *ts = from_timer(ts, t, timer);
+
+	schedule_work(&ts->work_i2c_poll);
+	mod_timer(&ts->timer, jiffies + msecs_to_jiffies(POLL_INTERVAL_MS));
+}
+
+static void goodix_ts_work_i2c_poll(struct work_struct *work)
+{
+	struct goodix_ts_data *ts = container_of(work,
+			struct goodix_ts_data, work_i2c_poll);
+
+	goodix_process_events(ts);
+	goodix_i2c_write_u8(ts->client, GOODIX_READ_COOR_ADDR, 0);
+}
+
+static void goodix_enable_irq(struct goodix_ts_data *ts)
+{
+	if (ts->client->irq) {
+		enable_irq(ts->client->irq);
+	} else {
+		ts->timer.expires = jiffies + msecs_to_jiffies(POLL_INTERVAL_MS);
+		add_timer(&ts->timer);
+	}
+}
+
+static void goodix_disable_irq(struct goodix_ts_data *ts)
+{
+	if (ts->client->irq) {
+		disable_irq(ts->client->irq);
+	} else {
+		del_timer(&ts->timer);
+		cancel_work_sync(&ts->work_i2c_poll);
+	}
+}
+
 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);
+	} else {
+		del_timer(&ts->timer);
+		cancel_work_sync(&ts->work_i2c_poll);
+	}
 }
 
 static int goodix_request_irq(struct goodix_ts_data *ts)
 {
-	return devm_request_threaded_irq(&ts->client->dev, ts->client->irq,
-					 NULL, goodix_ts_irq_handler,
-					 ts->irq_flags, ts->client->name, ts);
+	if (ts->client->irq) {
+		return devm_request_threaded_irq(&ts->client->dev, ts->client->irq,
+						 NULL, goodix_ts_irq_handler,
+						 ts->irq_flags, ts->client->name, ts);
+	} else {
+		INIT_WORK(&ts->work_i2c_poll,
+			  goodix_ts_work_i2c_poll);
+		timer_setup(&ts->timer, goodix_ts_irq_poll_timer, 0);
+		if (ts->irq_pin_access_method == IRQ_PIN_ACCESS_NONE)
+			goodix_enable_irq(ts);
+		return 0;
+	}
 }
 
 static int goodix_check_cfg_8(struct goodix_ts_data *ts, const u8 *cfg, int len)
@@ -1406,6 +1459,11 @@ static void goodix_ts_remove(struct i2c_client *client)
 {
 	struct goodix_ts_data *ts = i2c_get_clientdata(client);
 
+	if (!client->irq) {
+		del_timer(&ts->timer);
+		cancel_work_sync(&ts->work_i2c_poll);
+	}
+
 	if (ts->load_cfg_from_disk)
 		wait_for_completion(&ts->firmware_loading_complete);
 }
@@ -1421,7 +1479,7 @@ 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;
 	}
 
@@ -1465,7 +1523,7 @@ 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;
 	}
 
diff --git a/drivers/input/touchscreen/goodix.h b/drivers/input/touchscreen/goodix.h
index 87797cc..8a52621 100644
--- a/drivers/input/touchscreen/goodix.h
+++ b/drivers/input/touchscreen/goodix.h
@@ -104,6 +104,8 @@ struct goodix_ts_data {
 	u8 main_clk[GOODIX_MAIN_CLK_LEN];
 	int bak_ref_len;
 	u8 *bak_ref;
+	struct timer_list timer;
+	struct work_struct work_i2c_poll;
 };
 
 int goodix_i2c_read(struct i2c_client *client, u16 reg, u8 *buf, int len);
-- 
2.7.4