[PATCH v1 1/4] media: cadence: csi2rx: Support runtime PM

Changhuang Liang
2024-03-26T03:28:58Z

From: Jayshri Pawar <jpawar@cadence.com>

Use runtime power management hooks to save power when CSI-RX is not in
use. Also stop/start any in-progress streams, which might happen during
a system suspend/resume cycle.

Signed-off-by: Jayshri Pawar <jpawar@cadence.com>
Co-developed-by: Jai Luthra <j-luthra@ti.com>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Signed-off-by: Changhuang Liang <changhuang.liang@starfivetech.com>
---
drivers/media/platform/cadence/cdns-csi2rx.c | 43 +++++++++++++++++++-
1 file changed, 42 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index 2d7b0508cc9a..a8b86369e34f 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -364,6 +364,12 @@ static int csi2rx_s_stream(struct v4l2_subdev *subdev, int enable)
struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
int ret = 0;

+ if (enable) {
+ ret = pm_runtime_resume_and_get(csi2rx->dev);
+ if (ret < 0)
+ return ret;
+ }
+
mutex_lock(&csi2rx->lock);

if (enable) {
@@ -373,8 +379,10 @@ static int csi2rx_s_stream(struct v4l2_subdev *subdev, int enable)
*/
if (!csi2rx->count) {
ret = csi2rx_start(csi2rx);
- if (ret)
+ if (ret) {
+ pm_runtime_put(csi2rx->dev);
goto out;
+ }
}

csi2rx->count++;
@@ -386,6 +394,8 @@ static int csi2rx_s_stream(struct v4l2_subdev *subdev, int enable)
*/
if (!csi2rx->count)
csi2rx_stop(csi2rx);
+
+ pm_runtime_put(csi2rx->dev);
}

out:
@@ -659,6 +669,29 @@ static int csi2rx_parse_dt(struct csi2rx_priv *csi2rx)
return ret;
}

+static int csi2rx_suspend(struct device *dev)
+{
+ struct csi2rx_priv *csi2rx = dev_get_drvdata(dev);
+
+ mutex_lock(&csi2rx->lock);
+ if (csi2rx->count)
+ csi2rx_stop(csi2rx);
+ mutex_unlock(&csi2rx->lock);
+
+ return 0;
+}
+
+static int csi2rx_resume(struct device *dev)
+{
+ struct csi2rx_priv *csi2rx = dev_get_drvdata(dev);
+
+ mutex_lock(&csi2rx->lock);
+ if (csi2rx->count)
+ csi2rx_start(csi2rx);
+ mutex_unlock(&csi2rx->lock);
+ return 0;
+}
+
static int csi2rx_probe(struct platform_device *pdev)
{
struct csi2rx_priv *csi2rx;
@@ -705,6 +738,7 @@ static int csi2rx_probe(struct platform_device *pdev)
if (ret)
goto err_cleanup;

+ pm_runtime_enable(csi2rx->dev);
ret = v4l2_async_register_subdev(&csi2rx->subdev);
if (ret < 0)
goto err_free_state;
@@ -719,6 +753,7 @@ static int csi2rx_probe(struct platform_device *pdev)

err_free_state:
v4l2_subdev_cleanup(&csi2rx->subdev);
+ pm_runtime_disable(csi2rx->dev);
err_cleanup:
v4l2_async_nf_unregister(&csi2rx->notifier);
v4l2_async_nf_cleanup(&csi2rx->notifier);
@@ -737,9 +772,14 @@ static void csi2rx_remove(struct platform_device *pdev)
v4l2_async_unregister_subdev(&csi2rx->subdev);
v4l2_subdev_cleanup(&csi2rx->subdev);
media_entity_cleanup(&csi2rx->subdev.entity);
+ pm_runtime_disable(csi2rx->dev);
kfree(csi2rx);
}

+static const struct dev_pm_ops csi2rx_pm_ops = {
+ SET_RUNTIME_PM_OPS(csi2rx_suspend, csi2rx_resume, NULL)
+};
+
static const struct of_device_id csi2rx_of_table[] = {
{ .compatible = "starfive,jh7110-csi2rx" },
{ .compatible = "cdns,csi2rx" },
@@ -754,6 +794,7 @@ static struct platform_driver csi2rx_driver = {
.driver = {
.name = "cdns-csi2rx",
.of_match_table = csi2rx_of_table,
+ .pm = &csi2rx_pm_ops,
},
};
module_platform_driver(csi2rx_driver);
--
2.25.1