On Mon, 25 Mar 2019 15:49:28 +0100
Fabrice Gasnier <fabrice.gasnier@xxxxxx> wrote:
> 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: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
I'll confess that power management code always gives me a headache, but
I 'think' this looks right.
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.
Thanks,
Jonathan
> ---
> drivers/iio/adc/stm32-dfsdm-adc.c | 75 +++++++++++++++--
> drivers/iio/adc/stm32-dfsdm-core.c | 163 +++++++++++++++++++++++++++++++------
> 2 files changed, 206 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
> index 531ca7e..a599097 100644
> --- a/drivers/iio/adc/stm32-dfsdm-adc.c
> +++ b/drivers/iio/adc/stm32-dfsdm-adc.c
> @@ -851,24 +851,18 @@ 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);
> @@ -896,6 +890,26 @@ static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
> 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);
> @@ -903,7 +917,7 @@ static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
> 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);
>
> @@ -915,6 +929,11 @@ 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);
> @@ -1492,10 +1511,48 @@ 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,
> diff --git a/drivers/iio/adc/stm32-dfsdm-core.c b/drivers/iio/adc/stm32-dfsdm-core.c
> index 472b809..0a4d374 100644
> --- a/drivers/iio/adc/stm32-dfsdm-core.c
> +++ b/drivers/iio/adc/stm32-dfsdm-core.c
> @@ -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,
> },
> };
>
