[PATCH 07/14] iio: adc: rzg2l_adc: Enable runtime PM autosuspend support

[Claudiu]

From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>

Enable runtime PM autosuspend support for the rzg2l_adc driver. With this
change, consecutive conversion requests will no longer cause the device to
be runtime-enabled/disabled after each request. Instead, the device will
transition based on the delay configured by the user.

This approach reduces the frequency of hardware register access during
runtime PM suspend/resume cycles, thereby saving CPU cycles. The default
autosuspend delay is set to zero to maintain the previous driver behavior.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
---
 drivers/iio/adc/rzg2l_adc.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/rzg2l_adc.c b/drivers/iio/adc/rzg2l_adc.c
index eed2944bd98d..fda8b42ded81 100644
--- a/drivers/iio/adc/rzg2l_adc.c
+++ b/drivers/iio/adc/rzg2l_adc.c
@@ -207,7 +207,8 @@ static int rzg2l_adc_conversion(struct iio_dev *indio_dev, struct rzg2l_adc *adc
 	rzg2l_adc_start_stop(adc, false);
 
 rpm_put:
-	pm_runtime_put_sync(dev);
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
 	return ret;
 }
 
@@ -372,7 +373,8 @@ static int rzg2l_adc_hw_init(struct device *dev, struct rzg2l_adc *adc)
 	rzg2l_adc_writel(adc, RZG2L_ADM(3), reg);
 
 exit_hw_init:
-	pm_runtime_put_sync(dev);
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
 	return ret;
 }
 
@@ -412,6 +414,9 @@ static int rzg2l_adc_probe(struct platform_device *pdev)
 		return PTR_ERR(adc->presetn);
 	}
 
+	/* Default 0 for power saving. Can be overridden via sysfs. */
+	pm_runtime_set_autosuspend_delay(dev, 0);
+	pm_runtime_use_autosuspend(dev);
 	ret = devm_pm_runtime_enable(dev);
 	if (ret)
 		return ret;
-- 
2.39.2