[PATCH v3 3/3] input: touchscreen: st1232: add system wakeup support

[phucduc.bui@gmail.com]

From: bui duc phuc <phucduc.bui@gmail.com>

The ST1232 touchscreen controller can generate an interrupt when the
panel is touched, which may be used as a wakeup source for the system.

Add support for system wakeup by initializing the device wakeup
capability in probe() based on the "wakeup-source" device property.
When wakeup is enabled, the driver enables IRQ wake during suspend
so that touch events can wake the system.

If wakeup is not enabled, the driver retains the existing behavior of
disabling the IRQ and powering down the controller during suspend.

Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
---
Changes in v3:
 - Remove debug dev_info() messages to clean up the code and comply with
   upstream coding standards.

 drivers/input/touchscreen/st1232.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/input/touchscreen/st1232.c b/drivers/input/touchscreen/st1232.c
index 9b3901eec0a5..8fce17d8bdc0 100644
--- a/drivers/input/touchscreen/st1232.c
+++ b/drivers/input/touchscreen/st1232.c
@@ -183,6 +183,9 @@ static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
 	int count;
 	int error;
 
+	if (device_may_wakeup(&ts->client->dev))
+		pm_wakeup_event(&ts->client->dev, 0);
+
 	error = st1232_ts_read_data(ts, REG_XY_COORDINATES, ts->read_buf_len);
 	if (error)
 		goto out;
@@ -356,6 +359,9 @@ static int st1232_ts_probe(struct i2c_client *client)
 
 	i2c_set_clientdata(client, ts);
 
+	device_init_wakeup(&client->dev,
+			device_property_read_bool(&client->dev, "wakeup-source"));
+
 	return 0;
 }
 
@@ -364,10 +370,12 @@ static int st1232_ts_suspend(struct device *dev)
 	struct i2c_client *client = to_i2c_client(dev);
 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
 
-	disable_irq(client->irq);
-
-	if (!device_may_wakeup(&client->dev))
+	if (device_may_wakeup(dev)) {
+		enable_irq_wake(client->irq);
+	} else {
+		disable_irq(client->irq);
 		st1232_ts_power(ts, false);
+	}
 
 	return 0;
 }
@@ -377,10 +385,12 @@ static int st1232_ts_resume(struct device *dev)
 	struct i2c_client *client = to_i2c_client(dev);
 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
 
-	if (!device_may_wakeup(&client->dev))
+	if (device_may_wakeup(dev)) {
+		disable_irq_wake(client->irq);
+	} else {
 		st1232_ts_power(ts, true);
-
-	enable_irq(client->irq);
+		enable_irq(client->irq);
+	}
 
 	return 0;
 }
-- 
2.43.0