On Mon, 25 Mar 2019 15:49:28 +0100 Fabrice Gasnier <[email protected]> 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 <[email protected]> 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, > }, > }; >
