[PATCH 7/9] input: goodix: add power management support

[Irina Tirdea <irina.tirdea@intel.com>]

Implement suspend/resume for goodix driver.

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
---
 drivers/input/touchscreen/goodix.c | 81 +++++++++++++++++++++++++++++++++++---
 1 file changed, 76 insertions(+), 5 deletions(-)

diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index 22052c9..ce7e834 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -37,6 +37,7 @@ struct goodix_ts_data {
 	unsigned int int_trigger_type;
 	struct gpio_desc *gpiod_int;
 	struct gpio_desc *gpiod_rst;
+	unsigned long irq_flags;
 };
 
 #define GOODIX_GPIO_INT_NAME		"irq"
@@ -52,6 +53,9 @@ struct goodix_ts_data {
 #define GOODIX_CONFIG_MAX_LENGTH	240
 
 /* Register defines */
+#define GOODIX_REG_COMMAND		0x8040
+#define GOODIX_CMD_SCREEN_OFF		0x05
+
 #define GOODIX_READ_COOR_ADDR		0x814E
 #define GOODIX_REG_CONFIG_DATA		0x8047
 #define GOODIX_REG_ID			0x8140
@@ -129,6 +133,11 @@ static int goodix_i2c_write(struct i2c_client *client, u16 reg, u8 *buf,
 	return ret < 0 ? ret : (ret != 1 ? -EIO : 0);
 }
 
+static int goodix_i2c_write_u8(struct i2c_client *client, u16 reg, u8 value)
+{
+	return goodix_i2c_write(client, reg, &value, sizeof(value));
+}
+
 static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
 {
 	int touch_num;
@@ -227,6 +236,18 @@ static irqreturn_t goodix_ts_irq_handler(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static void goodix_free_irq(struct goodix_ts_data *ts)
+{
+	devm_free_irq(&ts->client->dev, ts->client->irq, ts);
+}
+
+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);
+}
+
 /**
  * goodix_get_cfg - Get device config from ACPI/DT.
  *
@@ -562,7 +583,6 @@ static int goodix_ts_probe(struct i2c_client *client,
 			   const struct i2c_device_id *id)
 {
 	struct goodix_ts_data *ts;
-	unsigned long irq_flags;
 	int error;
 	u16 version_info, id_info;
 
@@ -614,10 +634,8 @@ static int goodix_ts_probe(struct i2c_client *client,
 	if (error)
 		return error;
 
-	irq_flags = goodix_irq_flags[ts->int_trigger_type] | IRQF_ONESHOT;
-	error = devm_request_threaded_irq(&ts->client->dev, client->irq,
-					  NULL, goodix_ts_irq_handler,
-					  irq_flags, client->name, ts);
+	ts->irq_flags = goodix_irq_flags[ts->int_trigger_type] | IRQF_ONESHOT;
+	error = goodix_request_irq(ts);
 	if (error) {
 		dev_err(&client->dev, "request IRQ failed: %d\n", error);
 		return error;
@@ -626,6 +644,58 @@ static int goodix_ts_probe(struct i2c_client *client,
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int goodix_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct goodix_ts_data *ts = i2c_get_clientdata(client);
+	int ret;
+
+	goodix_free_irq(ts);
+	ret = gpiod_direction_output(ts->gpiod_int, 0);
+	if (ret) {
+		goodix_request_irq(ts);
+		return ret;
+	}
+	usleep_range(5000, 6000);
+
+	ret = goodix_i2c_write_u8(ts->client, GOODIX_REG_COMMAND,
+				  GOODIX_CMD_SCREEN_OFF);
+	if (ret) {
+		dev_err(&ts->client->dev, "Screen off command failed\n");
+		gpiod_direction_input(ts->gpiod_int);
+		goodix_request_irq(ts);
+		return -EAGAIN;
+	}
+
+	/*
+	 * To avoid waking up while is not sleeping,
+	 * delay 58ms to ensure reliability
+	 */
+	msleep(58);
+	return 0;
+}
+
+static int goodix_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct goodix_ts_data *ts = i2c_get_clientdata(client);
+	int ret;
+
+	ret = gpiod_direction_output(ts->gpiod_int, 1);
+	if (ret)
+		return ret;
+	usleep_range(2000, 5000);		/* 2ms~5ms */
+	ret = goodix_int_sync(ts);
+	if (ret)
+		return ret;
+
+	return goodix_request_irq(ts);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(goodix_pm_ops, goodix_suspend, goodix_resume);
+
 static const struct i2c_device_id goodix_ts_id[] = {
 	{ "GDIX1001:00", 0 },
 	{ }
@@ -663,6 +733,7 @@ static struct i2c_driver goodix_ts_driver = {
 		.owner = THIS_MODULE,
 		.acpi_match_table = ACPI_PTR(goodix_acpi_match),
 		.of_match_table = of_match_ptr(goodix_of_match),
+		.pm = &goodix_pm_ops,
 	},
 };
 module_i2c_driver(goodix_ts_driver);
-- 
1.9.1