From 49ad8d289284b28fcac73a04838bf8eb39fd058d Mon Sep 17 00:00:00 2001 From: Fabrice Gasnier Date: Tue, 20 Nov 2018 11:12:32 +0100 Subject: [PATCH] iio: adc: stm32-adc: switch off running adc when going to low power Switch off ADC when going to low power mode, in case it has been left running in buffer mode. Then re-enable it when resuming. Signed-off-by: Fabrice Gasnier Signed-off-by: Jonathan Cameron --- drivers/iio/adc/stm32-adc.c | 79 +++++++++++++++++++++++++++++-------- 1 file changed, 63 insertions(+), 16 deletions(-) diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c index 1ba800b91273..205e1699f954 100644 --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -1518,7 +1518,7 @@ static int stm32_adc_dma_start(struct iio_dev *indio_dev) return 0; } -static int stm32_adc_buffer_postenable(struct iio_dev *indio_dev) +static int __stm32_adc_buffer_postenable(struct iio_dev *indio_dev) { struct stm32_adc *adc = iio_priv(indio_dev); struct device *dev = indio_dev->dev.parent; @@ -1542,10 +1542,6 @@ static int stm32_adc_buffer_postenable(struct iio_dev *indio_dev) goto err_clr_trig; } - ret = iio_triggered_buffer_postenable(indio_dev); - if (ret < 0) - goto err_stop_dma; - /* Reset adc buffer index */ adc->bufi = 0; @@ -1556,9 +1552,6 @@ static int stm32_adc_buffer_postenable(struct iio_dev *indio_dev) return 0; -err_stop_dma: - if (adc->dma_chan) - dmaengine_terminate_all(adc->dma_chan); err_clr_trig: stm32_adc_set_trig(indio_dev, NULL); err_pm_put: @@ -1568,20 +1561,30 @@ err_pm_put: return ret; } -static int stm32_adc_buffer_predisable(struct iio_dev *indio_dev) +static int stm32_adc_buffer_postenable(struct iio_dev *indio_dev) +{ + int ret; + + ret = iio_triggered_buffer_postenable(indio_dev); + if (ret < 0) + return ret; + + ret = __stm32_adc_buffer_postenable(indio_dev); + if (ret < 0) + iio_triggered_buffer_predisable(indio_dev); + + return ret; +} + +static void __stm32_adc_buffer_predisable(struct iio_dev *indio_dev) { struct stm32_adc *adc = iio_priv(indio_dev); struct device *dev = indio_dev->dev.parent; - int ret; adc->cfg->stop_conv(adc); if (!adc->dma_chan) stm32_adc_conv_irq_disable(adc); - ret = iio_triggered_buffer_predisable(indio_dev); - if (ret < 0) - dev_err(&indio_dev->dev, "predisable failed\n"); - if (adc->dma_chan) dmaengine_terminate_all(adc->dma_chan); @@ -1590,6 +1593,17 @@ static int stm32_adc_buffer_predisable(struct iio_dev *indio_dev) pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); +} + +static int stm32_adc_buffer_predisable(struct iio_dev *indio_dev) +{ + int ret; + + __stm32_adc_buffer_predisable(indio_dev); + + ret = iio_triggered_buffer_predisable(indio_dev); + if (ret < 0) + dev_err(&indio_dev->dev, "predisable failed\n"); return ret; } @@ -2013,6 +2027,40 @@ static int stm32_adc_remove(struct platform_device *pdev) return 0; } +#if defined(CONFIG_PM_SLEEP) +static int stm32_adc_suspend(struct device *dev) +{ + struct stm32_adc *adc = dev_get_drvdata(dev); + struct iio_dev *indio_dev = iio_priv_to_dev(adc); + + if (iio_buffer_enabled(indio_dev)) + __stm32_adc_buffer_predisable(indio_dev); + + return pm_runtime_force_suspend(dev); +} + +static int stm32_adc_resume(struct device *dev) +{ + struct stm32_adc *adc = dev_get_drvdata(dev); + struct iio_dev *indio_dev = iio_priv_to_dev(adc); + int ret; + + ret = pm_runtime_force_resume(dev); + if (ret < 0) + return ret; + + if (!iio_buffer_enabled(indio_dev)) + return 0; + + ret = stm32_adc_update_scan_mode(indio_dev, + indio_dev->active_scan_mask); + if (ret < 0) + return ret; + + return __stm32_adc_buffer_postenable(indio_dev); +} +#endif + #if defined(CONFIG_PM) static int stm32_adc_runtime_suspend(struct device *dev) { @@ -2026,8 +2074,7 @@ static int stm32_adc_runtime_resume(struct device *dev) #endif static const struct dev_pm_ops stm32_adc_pm_ops = { - SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, - pm_runtime_force_resume) + SET_SYSTEM_SLEEP_PM_OPS(stm32_adc_suspend, stm32_adc_resume) SET_RUNTIME_PM_OPS(stm32_adc_runtime_suspend, stm32_adc_runtime_resume, NULL) }; -- 2.30.2