Commit 6ec417d2 authored by Fabrice Gasnier's avatar Fabrice Gasnier Committed by Jonathan Cameron
Browse files

iio: adc: stm32-dfsdm: add PM support 



Add PM and runtime PM support to STM32 DFSDM drivers:
- stm32-dfsdm-core: manage clocks.
- stm32-dfsdm-adc: restore channels configuration upon resume. Also stop
  restart everything in case of buffer mode.

Signed-off-by: default avatarFabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 9f57110d

drivers/iio/adc/stm32-dfsdm-adc.c

+66 −9
Original line number Diff line number Diff line
@@ -868,24 +868,18 @@ static int stm32_dfsdm_update_scan_mode(struct iio_dev *indio_dev, 
	return 0;

}



static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)

static int __stm32_dfsdm_postenable(struct iio_dev *indio_dev)

{

	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);

	int ret;



	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {

		ret = iio_triggered_buffer_postenable(indio_dev);

		if (ret < 0)

			return ret;

	}



	/* Reset adc buffer index */

	adc->bufi = 0;



	if (adc->hwc) {

		ret = iio_hw_consumer_enable(adc->hwc);

		if (ret < 0)

			goto err_predisable;

			return ret;

	}



	ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
@@ -913,6 +907,26 @@ stop_dfsdm: 
err_stop_hwc:

	if (adc->hwc)

		iio_hw_consumer_disable(adc->hwc);



	return ret;

}



static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)

{

	int ret;



	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {

		ret = iio_triggered_buffer_postenable(indio_dev);

		if (ret < 0)

			return ret;

	}



	ret = __stm32_dfsdm_postenable(indio_dev);

	if (ret < 0)

		goto err_predisable;



	return 0;



err_predisable:

	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED)

		iio_triggered_buffer_predisable(indio_dev);
@@ -920,7 +934,7 @@ err_predisable: 
	return ret;

}



static int stm32_dfsdm_predisable(struct iio_dev *indio_dev)

static void __stm32_dfsdm_predisable(struct iio_dev *indio_dev)

{

	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
@@ -932,6 +946,11 @@ static int stm32_dfsdm_predisable(struct iio_dev *indio_dev) 


	if (adc->hwc)

		iio_hw_consumer_disable(adc->hwc);

}



static int stm32_dfsdm_predisable(struct iio_dev *indio_dev)

{

	__stm32_dfsdm_predisable(indio_dev);



	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED)

		iio_triggered_buffer_predisable(indio_dev);
@@ -1496,10 +1515,48 @@ static int stm32_dfsdm_adc_remove(struct platform_device *pdev) 
	return 0;

}



static int __maybe_unused stm32_dfsdm_adc_suspend(struct device *dev)

{

	struct stm32_dfsdm_adc *adc = dev_get_drvdata(dev);

	struct iio_dev *indio_dev = iio_priv_to_dev(adc);



	if (iio_buffer_enabled(indio_dev))

		__stm32_dfsdm_predisable(indio_dev);



	return 0;

}



static int __maybe_unused stm32_dfsdm_adc_resume(struct device *dev)

{

	struct stm32_dfsdm_adc *adc = dev_get_drvdata(dev);

	struct iio_dev *indio_dev = iio_priv_to_dev(adc);

	const struct iio_chan_spec *chan;

	struct stm32_dfsdm_channel *ch;

	int i, ret;



	/* restore channels configuration */

	for (i = 0; i < indio_dev->num_channels; i++) {

		chan = indio_dev->channels + i;

		ch = &adc->dfsdm->ch_list[chan->channel];

		ret = stm32_dfsdm_chan_configure(adc->dfsdm, ch);

		if (ret)

			return ret;

	}



	if (iio_buffer_enabled(indio_dev))

		__stm32_dfsdm_postenable(indio_dev);



	return 0;

}



static SIMPLE_DEV_PM_OPS(stm32_dfsdm_adc_pm_ops,

			 stm32_dfsdm_adc_suspend, stm32_dfsdm_adc_resume);



static struct platform_driver stm32_dfsdm_adc_driver = {

	.driver = {

		.name = "stm32-dfsdm-adc",

		.of_match_table = stm32_dfsdm_adc_match,

		.pm = &stm32_dfsdm_adc_pm_ops,

	},

	.probe = stm32_dfsdm_adc_probe,

	.remove = stm32_dfsdm_adc_remove,

drivers/iio/adc/stm32-dfsdm-core.c

+140 −23
Original line number Diff line number Diff line
@@ -12,6 +12,8 @@ 
#include <linux/interrupt.h>

#include <linux/module.h>

#include <linux/of_device.h>

#include <linux/pinctrl/consumer.h>

#include <linux/pm_runtime.h>

#include <linux/regmap.h>

#include <linux/slab.h>
@@ -90,6 +92,36 @@ struct dfsdm_priv { 
	struct clk *aclk; /* audio clock */

};



static inline struct dfsdm_priv *to_stm32_dfsdm_priv(struct stm32_dfsdm *dfsdm)

{

	return container_of(dfsdm, struct dfsdm_priv, dfsdm);

}



static int stm32_dfsdm_clk_prepare_enable(struct stm32_dfsdm *dfsdm)

{

	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);

	int ret;



	ret = clk_prepare_enable(priv->clk);

	if (ret || !priv->aclk)

		return ret;



	ret = clk_prepare_enable(priv->aclk);

	if (ret)

		clk_disable_unprepare(priv->clk);



	return ret;

}



static void stm32_dfsdm_clk_disable_unprepare(struct stm32_dfsdm *dfsdm)

{

	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);



	if (priv->aclk)

		clk_disable_unprepare(priv->aclk);

	clk_disable_unprepare(priv->clk);

}



/**

 * stm32_dfsdm_start_dfsdm - start global dfsdm interface.

 *
@@ -98,24 +130,17 @@ struct dfsdm_priv { 
 */

int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm)

{

	struct dfsdm_priv *priv = container_of(dfsdm, struct dfsdm_priv, dfsdm);

	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);

	struct device *dev = &priv->pdev->dev;

	unsigned int clk_div = priv->spi_clk_out_div, clk_src;

	int ret;



	if (atomic_inc_return(&priv->n_active_ch) == 1) {

		ret = clk_prepare_enable(priv->clk);

		ret = pm_runtime_get_sync(dev);

		if (ret < 0) {

			dev_err(dev, "Failed to start clock\n");

			pm_runtime_put_noidle(dev);

			goto error_ret;

		}

		if (priv->aclk) {

			ret = clk_prepare_enable(priv->aclk);

			if (ret < 0) {

				dev_err(dev, "Failed to start audio clock\n");

				goto disable_clk;

			}

		}



		/* select clock source, e.g. 0 for "dfsdm" or 1 for "audio" */

		clk_src = priv->aclk ? 1 : 0;
@@ -123,21 +148,21 @@ int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm) 
					 DFSDM_CHCFGR1_CKOUTSRC_MASK,

					 DFSDM_CHCFGR1_CKOUTSRC(clk_src));

		if (ret < 0)

			goto disable_aclk;

			goto pm_put;



		/* Output the SPI CLKOUT (if clk_div == 0 clock if OFF) */

		ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),

					 DFSDM_CHCFGR1_CKOUTDIV_MASK,

					 DFSDM_CHCFGR1_CKOUTDIV(clk_div));

		if (ret < 0)

			goto disable_aclk;

			goto pm_put;



		/* Global enable of DFSDM interface */

		ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),

					 DFSDM_CHCFGR1_DFSDMEN_MASK,

					 DFSDM_CHCFGR1_DFSDMEN(1));

		if (ret < 0)

			goto disable_aclk;

			goto pm_put;

	}



	dev_dbg(dev, "%s: n_active_ch %d\n", __func__,
@@ -145,11 +170,8 @@ int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm) 


	return 0;



disable_aclk:

	clk_disable_unprepare(priv->aclk);

disable_clk:

	clk_disable_unprepare(priv->clk);



pm_put:

	pm_runtime_put_sync(dev);

error_ret:

	atomic_dec(&priv->n_active_ch);
@@ -165,7 +187,7 @@ EXPORT_SYMBOL_GPL(stm32_dfsdm_start_dfsdm); 
 */

int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm)

{

	struct dfsdm_priv *priv = container_of(dfsdm, struct dfsdm_priv, dfsdm);

	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);

	int ret;



	if (atomic_dec_and_test(&priv->n_active_ch)) {
@@ -183,9 +205,7 @@ int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm) 
		if (ret < 0)

			return ret;



		clk_disable_unprepare(priv->clk);

		if (priv->aclk)

			clk_disable_unprepare(priv->aclk);

		pm_runtime_put_sync(&priv->pdev->dev);

	}

	dev_dbg(&priv->pdev->dev, "%s: n_active_ch %d\n", __func__,

		atomic_read(&priv->n_active_ch));
@@ -325,14 +345,111 @@ static int stm32_dfsdm_probe(struct platform_device *pdev) 


	platform_set_drvdata(pdev, dfsdm);



	return devm_of_platform_populate(&pdev->dev);

	ret = stm32_dfsdm_clk_prepare_enable(dfsdm);

	if (ret) {

		dev_err(&pdev->dev, "Failed to start clock\n");

		return ret;

	}



	pm_runtime_get_noresume(&pdev->dev);

	pm_runtime_set_active(&pdev->dev);

	pm_runtime_enable(&pdev->dev);



	ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);

	if (ret)

		goto pm_put;



	pm_runtime_put(&pdev->dev);



	return 0;



pm_put:

	pm_runtime_disable(&pdev->dev);

	pm_runtime_set_suspended(&pdev->dev);

	pm_runtime_put_noidle(&pdev->dev);

	stm32_dfsdm_clk_disable_unprepare(dfsdm);



	return ret;

}



static int stm32_dfsdm_core_remove(struct platform_device *pdev)

{

	struct stm32_dfsdm *dfsdm = platform_get_drvdata(pdev);



	pm_runtime_get_sync(&pdev->dev);

	of_platform_depopulate(&pdev->dev);

	pm_runtime_disable(&pdev->dev);

	pm_runtime_set_suspended(&pdev->dev);

	pm_runtime_put_noidle(&pdev->dev);

	stm32_dfsdm_clk_disable_unprepare(dfsdm);



	return 0;

}



static int __maybe_unused stm32_dfsdm_core_suspend(struct device *dev)

{

	struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);

	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);

	int ret;



	ret = pm_runtime_force_suspend(dev);

	if (ret)

		return ret;



	/* Balance devm_regmap_init_mmio_clk() clk_prepare() */

	clk_unprepare(priv->clk);



	return pinctrl_pm_select_sleep_state(dev);

}



static int __maybe_unused stm32_dfsdm_core_resume(struct device *dev)

{

	struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);

	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);

	int ret;



	ret = pinctrl_pm_select_default_state(dev);

	if (ret)

		return ret;



	ret = clk_prepare(priv->clk);

	if (ret)

		return ret;



	return pm_runtime_force_resume(dev);

}



static int __maybe_unused stm32_dfsdm_core_runtime_suspend(struct device *dev)

{

	struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);



	stm32_dfsdm_clk_disable_unprepare(dfsdm);



	return 0;

}



static int __maybe_unused stm32_dfsdm_core_runtime_resume(struct device *dev)

{

	struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);



	return stm32_dfsdm_clk_prepare_enable(dfsdm);

}



static const struct dev_pm_ops stm32_dfsdm_core_pm_ops = {

	SET_SYSTEM_SLEEP_PM_OPS(stm32_dfsdm_core_suspend,

				stm32_dfsdm_core_resume)

	SET_RUNTIME_PM_OPS(stm32_dfsdm_core_runtime_suspend,

			   stm32_dfsdm_core_runtime_resume,

			   NULL)

};



static struct platform_driver stm32_dfsdm_driver = {

	.probe = stm32_dfsdm_probe,

	.remove = stm32_dfsdm_core_remove,

	.driver = {

		.name = "stm32-dfsdm",

		.of_match_table = stm32_dfsdm_of_match,

		.pm = &stm32_dfsdm_core_pm_ops,

	},

};

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