[PATCH v2 6/8] media: i2c: ov5670: Add runtime_pm operations

[Jacopo Mondi <jacopo@jmondi.org>]

Implement the power up and power down routines and install them as
runtime_pm handler for runtime_suspend and runtime_resume operations.

Rework the runtime_pm enablement and the chip power handling during
probe, as calling pm_runtime_idle() in a driver that registers no
idle callback is a nop.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
---
 drivers/media/i2c/ov5670.c | 58 ++++++++++++++++++++++++++++++++++----
 1 file changed, 52 insertions(+), 6 deletions(-)

diff --git a/drivers/media/i2c/ov5670.c b/drivers/media/i2c/ov5670.c
index 1ecc3e549737..c3f773524d5f 100644
--- a/drivers/media/i2c/ov5670.c
+++ b/drivers/media/i2c/ov5670.c
@@ -4,6 +4,7 @@
 #include <linux/acpi.h>
 #include <linux/clk.h>
 #include <linux/gpio/consumer.h>
+#include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
@@ -2426,6 +2427,39 @@ static int ov5670_set_stream(struct v4l2_subdev *sd, int enable)
 	return ret;
 }
 
+static int __maybe_unused ov5670_runtime_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct ov5670 *ov5670 = to_ov5670(sd);
+	int ret;
+
+	ret = regulator_bulk_enable(OV5670_NUM_SUPPLIES, ov5670->supplies);
+	if (ret)
+		return ret;
+
+	gpiod_set_value_cansleep(ov5670->pwdn_gpio, 0);
+	gpiod_set_value_cansleep(ov5670->reset_gpio, 0);
+
+	/* 8192 * 2 clock pulses before the first SCCB transaction. */
+	usleep_range(1000, 1500);
+
+	return 0;
+}
+
+static int __maybe_unused ov5670_runtime_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct ov5670 *ov5670 = to_ov5670(sd);
+
+	gpiod_set_value_cansleep(ov5670->reset_gpio, 1);
+	gpiod_set_value_cansleep(ov5670->pwdn_gpio, 1);
+	regulator_bulk_disable(OV5670_NUM_SUPPLIES, ov5670->supplies);
+
+	return 0;
+}
+
 static int __maybe_unused ov5670_suspend(struct device *dev)
 {
 	struct v4l2_subdev *sd = dev_get_drvdata(dev);
@@ -2563,14 +2597,25 @@ static int ov5670_probe(struct i2c_client *client)
 		goto error_print;
 	}
 
+	pm_runtime_enable(&client->dev);
+
 	full_power = acpi_dev_state_d0(&client->dev);
 	if (full_power) {
+		ret = pm_runtime_resume_and_get(&client->dev);
+		if (ret) {
+			err_msg = "Failed to power on";
+			goto error_print;
+		}
+
 		/* Check module identity */
 		ret = ov5670_identify_module(ov5670);
 		if (ret) {
 			err_msg = "ov5670_identify_module() error";
-			goto error_print;
+			goto error_power_off;
 		}
+
+		/* Set the device's state to active if it's in D0 state. */
+		pm_runtime_set_active(&client->dev);
 	}
 
 	mutex_init(&ov5670->mutex);
@@ -2607,11 +2652,7 @@ static int ov5670_probe(struct i2c_client *client)
 
 	ov5670->streaming = false;
 
-	/* Set the device's state to active if it's in D0 state. */
-	if (full_power)
-		pm_runtime_set_active(&client->dev);
-	pm_runtime_enable(&client->dev);
-	pm_runtime_idle(&client->dev);
+	pm_runtime_suspend(&client->dev);
 
 	return 0;
 
@@ -2624,6 +2665,9 @@ static int ov5670_probe(struct i2c_client *client)
 error_mutex_destroy:
 	mutex_destroy(&ov5670->mutex);
 
+error_power_off:
+	pm_runtime_put(&client->dev);
+
 error_print:
 	dev_err(&client->dev, "%s: %s %d\n", __func__, err_msg, ret);
 
@@ -2640,6 +2684,7 @@ static int ov5670_remove(struct i2c_client *client)
 	v4l2_ctrl_handler_free(sd->ctrl_handler);
 	mutex_destroy(&ov5670->mutex);
 
+	pm_runtime_put(&client->dev);
 	pm_runtime_disable(&client->dev);
 
 	return 0;
@@ -2647,6 +2692,7 @@ static int ov5670_remove(struct i2c_client *client)
 
 static const struct dev_pm_ops ov5670_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(ov5670_suspend, ov5670_resume)
+	SET_RUNTIME_PM_OPS(ov5670_runtime_suspend, ov5670_runtime_resume, NULL)
 };
 
 #ifdef CONFIG_ACPI
-- 
2.35.1