Commit 563cf94f authored by Claudiu Beznea's avatar Claudiu Beznea Committed by Jonathan Cameron
Browse files

iio: adc: rzg2l_adc: Add suspend/resume support 



The Renesas RZ/G3S SoC features a power-saving mode where power to most of
the SoC components is turned off, including the ADC IP.

Suspend/resume support has been added to the rzg2l_adc driver to restore
functionality after resuming from this power-saving mode. During suspend,
the ADC resets are asserted, and the ADC is powered down. On resume, the
ADC resets are de-asserted, the hardware is re-initialized, and the ADC
power is restored using the runtime PM APIs.

Signed-off-by: default avatarClaudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: default avatarLad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://patch.msgid.link/20241206111337.726244-12-claudiu.beznea.uj@bp.renesas.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 6dd8a771

drivers/iio/adc/rzg2l_adc.c

+70 −0
Original line number Diff line number Diff line
@@ -88,6 +88,7 @@ struct rzg2l_adc { 
	struct completion completion;

	struct mutex lock;

	u16 last_val[RZG2L_ADC_MAX_CHANNELS];

	bool was_rpm_active;

};



/**
@@ -529,8 +530,77 @@ static int rzg2l_adc_pm_runtime_resume(struct device *dev) 
	return 0;

}



static int rzg2l_adc_suspend(struct device *dev)

{

	struct iio_dev *indio_dev = dev_get_drvdata(dev);

	struct rzg2l_adc *adc = iio_priv(indio_dev);

	struct reset_control_bulk_data resets[] = {

		{ .rstc = adc->presetn },

		{ .rstc = adc->adrstn },

	};

	int ret;



	if (pm_runtime_suspended(dev)) {

		adc->was_rpm_active = false;

	} else {

		ret = pm_runtime_force_suspend(dev);

		if (ret)

			return ret;

		adc->was_rpm_active = true;

	}



	ret = reset_control_bulk_assert(ARRAY_SIZE(resets), resets);

	if (ret)

		goto rpm_restore;



	return 0;



rpm_restore:

	if (adc->was_rpm_active)

		pm_runtime_force_resume(dev);



	return ret;

}



static int rzg2l_adc_resume(struct device *dev)

{

	struct iio_dev *indio_dev = dev_get_drvdata(dev);

	struct rzg2l_adc *adc = iio_priv(indio_dev);

	struct reset_control_bulk_data resets[] = {

		{ .rstc = adc->adrstn },

		{ .rstc = adc->presetn },

	};

	int ret;



	ret = reset_control_bulk_deassert(ARRAY_SIZE(resets), resets);

	if (ret)

		return ret;



	if (adc->was_rpm_active) {

		ret = pm_runtime_force_resume(dev);

		if (ret)

			goto resets_restore;

	}



	ret = rzg2l_adc_hw_init(dev, adc);

	if (ret)

		goto rpm_restore;



	return 0;



rpm_restore:

	if (adc->was_rpm_active) {

		pm_runtime_mark_last_busy(dev);

		pm_runtime_put_autosuspend(dev);

	}

resets_restore:

	reset_control_bulk_assert(ARRAY_SIZE(resets), resets);

	return ret;

}



static const struct dev_pm_ops rzg2l_adc_pm_ops = {

	RUNTIME_PM_OPS(rzg2l_adc_pm_runtime_suspend, rzg2l_adc_pm_runtime_resume, NULL)

	SYSTEM_SLEEP_PM_OPS(rzg2l_adc_suspend, rzg2l_adc_resume)

};



static struct platform_driver rzg2l_adc_driver = {