[PATCH v3 1/2] input: touchscreen: pixcir_i2c_ts: Add support for optional wakeup interrupt

[Vignesh R]

On am437x-gp-evm, pixcir touchscreen can wake the system from low power
state by generating wake-up interrupt via pinctrl and IO daisy chain.
Add support for optional wakeup interrupt source by regsitering to
automated wake IRQ framework introduced by commit 4990d4fe327b ("PM /
Wakeirq: Add automated device wake IRQ handling").
This is similar in approach to commit 2a0b965cfb6e ("serial: omap: Add
support for optional wake-up")

Signed-off-by: Vignesh R <vigneshr at ti.com>
---

v3:
 * handle error code returned by of_irq_get_byname()

v2:
 * use of_irq_get_byname()
 * remove enable/disable_wake_irq()

 drivers/input/touchscreen/pixcir_i2c_ts.c | 22 ++++++++++++++++++----
 include/linux/input/pixcir_ts.h           |  1 +
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/input/touchscreen/pixcir_i2c_ts.c b/drivers/input/touchscreen/pixcir_i2c_ts.c
index 8f3e243a62bf..3a4ab358bf52 100644
--- a/drivers/input/touchscreen/pixcir_i2c_ts.c
+++ b/drivers/input/touchscreen/pixcir_i2c_ts.c
@@ -29,6 +29,8 @@
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/pm_wakeirq.h>
 
 #define PIXCIR_MAX_SLOTS       5 /* Max fingers supported by driver */
 
@@ -364,8 +366,6 @@ static int __maybe_unused pixcir_i2c_ts_suspend(struct device *dev)
 				goto unlock;
 			}
 		}
-
-		enable_irq_wake(client->irq);
 	} else if (input->users) {
 		ret = pixcir_stop(ts);
 	}
@@ -386,8 +386,6 @@ static int __maybe_unused pixcir_i2c_ts_resume(struct device *dev)
 	mutex_lock(&input->mutex);
 
 	if (device_may_wakeup(&client->dev)) {
-		disable_irq_wake(client->irq);
-
 		if (!input->users) {
 			ret = pixcir_stop(ts);
 			if (ret) {
@@ -445,6 +443,13 @@ static struct pixcir_ts_platform_data *pixcir_parse_dt(struct device *dev)
 	dev_dbg(dev, "%s: x %d, y %d, gpio %d\n", __func__,
 		pdata->x_max + 1, pdata->y_max + 1, pdata->gpio_attb);
 
+	pdata->wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
+	if (pdata->wakeirq < 0 && pdata->wakeirq != -ENODATA &&
+	    pdata->wakeirq != -EINVAL) {
+		dev_err(dev, "Failed to get wakeirq\n");
+		return ERR_PTR(pdata->wakeirq);
+	}
+
 	return pdata;
 }
 #else
@@ -564,11 +569,20 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
 	i2c_set_clientdata(client, tsdata);
 	device_init_wakeup(&client->dev, 1);
 
+	/* Register wakeirq */
+	error = (pdata->wakeirq > 0) ?
+		dev_pm_set_dedicated_wake_irq(dev, pdata->wakeirq) :
+		dev_pm_set_wake_irq(dev, client->irq);
+	if (error)
+		dev_info(dev, "unable to setup wakeirq %d\n",
+			 error);
+
 	return 0;
 }
 
 static int pixcir_i2c_ts_remove(struct i2c_client *client)
 {
+	dev_pm_clear_wake_irq(&client->dev);
 	device_init_wakeup(&client->dev, 0);
 
 	return 0;
diff --git a/include/linux/input/pixcir_ts.h b/include/linux/input/pixcir_ts.h
index 7bae83b7c396..da573de5a5ee 100644
--- a/include/linux/input/pixcir_ts.h
+++ b/include/linux/input/pixcir_ts.h
@@ -58,6 +58,7 @@ struct pixcir_ts_platform_data {
 	int x_max;
 	int y_max;
 	int gpio_attb;		/* GPIO connected to ATTB line */
+	int wakeirq;
 	struct pixcir_i2c_chip_data chip;
 };
 
-- 
2.4.5