[PATCH v2 08/15] iio: adc: rzg2l_adc: Enable runtime PM autosuspend support

Claudiu
2024-12-06T11:14:09Z

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

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.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

Changes in v2:
- used a non-zero default autosusped delay
- adjusted the patch description to reflect that the default autosuspend
delay has been changed

drivers/iio/adc/rzg2l_adc.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/rzg2l_adc.c b/drivers/iio/adc/rzg2l_adc.c
index 953511191eac..c3f9f95cdbba 100644
--- a/drivers/iio/adc/rzg2l_adc.c
+++ b/drivers/iio/adc/rzg2l_adc.c
@@ -208,7 +208,8 @@ 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;
}

@@ -410,6 +412,8 @@ static int rzg2l_adc_probe(struct platform_device *pdev)
"failed to get/deassert presetn\n");
}

+ pm_runtime_set_autosuspend_delay(dev, 300);
+ pm_runtime_use_autosuspend(dev);
ret = devm_pm_runtime_enable(dev);
if (ret)
return ret;
--
2.39.2