From 152e0bf60219ba589254c7aff4c095943c36cf68 Mon Sep 17 00:00:00 2001 From: Hugues Fruchet Date: Wed, 13 Jun 2018 05:59:39 -0400 Subject: [PATCH] media: stm32-dcmi: add power saving support Implements runtime & system sleep power management ops. Signed-off-by: Hugues Fruchet Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/stm32/stm32-dcmi.c | 81 +++++++++++++++++++++++++------ 1 file changed, 65 insertions(+), 16 deletions(-) diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c index 4f65f14..7215641 100644 --- a/drivers/media/platform/stm32/stm32-dcmi.c +++ b/drivers/media/platform/stm32/stm32-dcmi.c @@ -22,7 +22,9 @@ #include #include #include +#include #include +#include #include #include @@ -567,9 +569,9 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count) u32 val = 0; int ret; - ret = clk_enable(dcmi->mclk); + ret = pm_runtime_get_sync(dcmi->dev); if (ret) { - dev_err(dcmi->dev, "%s: Failed to start streaming, cannot enable clock\n", + dev_err(dcmi->dev, "%s: Failed to start streaming, cannot get sync\n", __func__); goto err_release_buffers; } @@ -579,7 +581,7 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count) if (ret && ret != -ENOIOCTLCMD) { dev_err(dcmi->dev, "%s: Failed to start streaming, subdev streamon error", __func__); - goto err_disable_clock; + goto err_pm_put; } spin_lock_irq(&dcmi->irqlock); @@ -664,8 +666,8 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count) err_subdev_streamoff: v4l2_subdev_call(dcmi->entity.subdev, video, s_stream, 0); -err_disable_clock: - clk_disable(dcmi->mclk); +err_pm_put: + pm_runtime_put(dcmi->dev); err_release_buffers: spin_lock_irq(&dcmi->irqlock); @@ -717,7 +719,7 @@ static void dcmi_stop_streaming(struct vb2_queue *vq) /* Stop all pending DMA operations */ dmaengine_terminate_all(dcmi->dma_chan); - clk_disable(dcmi->mclk); + pm_runtime_put(dcmi->dev); if (dcmi->errors_count) dev_warn(dcmi->dev, "Some errors found while streaming: errors=%d (overrun=%d), buffers=%d\n", @@ -1707,12 +1709,6 @@ static int dcmi_probe(struct platform_device *pdev) return -EPROBE_DEFER; } - ret = clk_prepare(mclk); - if (ret) { - dev_err(&pdev->dev, "Unable to prepare mclk %p\n", mclk); - goto err_dma_release; - } - spin_lock_init(&dcmi->irqlock); mutex_init(&dcmi->lock); init_completion(&dcmi->complete); @@ -1728,7 +1724,7 @@ static int dcmi_probe(struct platform_device *pdev) /* Initialize the top-level structure */ ret = v4l2_device_register(&pdev->dev, &dcmi->v4l2_dev); if (ret) - goto err_clk_unprepare; + goto err_dma_release; dcmi->vdev = video_device_alloc(); if (!dcmi->vdev) { @@ -1788,14 +1784,15 @@ static int dcmi_probe(struct platform_device *pdev) dev_info(&pdev->dev, "Probe done\n"); platform_set_drvdata(pdev, dcmi); + + pm_runtime_enable(&pdev->dev); + return 0; err_device_release: video_device_release(dcmi->vdev); err_device_unregister: v4l2_device_unregister(&dcmi->v4l2_dev); -err_clk_unprepare: - clk_unprepare(dcmi->mclk); err_dma_release: dma_release_channel(dcmi->dma_chan); @@ -1806,20 +1803,72 @@ static int dcmi_remove(struct platform_device *pdev) { struct stm32_dcmi *dcmi = platform_get_drvdata(pdev); + pm_runtime_disable(&pdev->dev); + v4l2_async_notifier_unregister(&dcmi->notifier); v4l2_device_unregister(&dcmi->v4l2_dev); - clk_unprepare(dcmi->mclk); + dma_release_channel(dcmi->dma_chan); return 0; } +static __maybe_unused int dcmi_runtime_suspend(struct device *dev) +{ + struct stm32_dcmi *dcmi = dev_get_drvdata(dev); + + clk_disable_unprepare(dcmi->mclk); + + return 0; +} + +static __maybe_unused int dcmi_runtime_resume(struct device *dev) +{ + struct stm32_dcmi *dcmi = dev_get_drvdata(dev); + int ret; + + ret = clk_prepare_enable(dcmi->mclk); + if (ret) + dev_err(dev, "%s: Failed to prepare_enable clock\n", __func__); + + return ret; +} + +static __maybe_unused int dcmi_suspend(struct device *dev) +{ + /* disable clock */ + pm_runtime_force_suspend(dev); + + /* change pinctrl state */ + pinctrl_pm_select_sleep_state(dev); + + return 0; +} + +static __maybe_unused int dcmi_resume(struct device *dev) +{ + /* restore pinctl default state */ + pinctrl_pm_select_default_state(dev); + + /* clock enable */ + pm_runtime_force_resume(dev); + + return 0; +} + +static const struct dev_pm_ops dcmi_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(dcmi_suspend, dcmi_resume) + SET_RUNTIME_PM_OPS(dcmi_runtime_suspend, + dcmi_runtime_resume, NULL) +}; + static struct platform_driver stm32_dcmi_driver = { .probe = dcmi_probe, .remove = dcmi_remove, .driver = { .name = DRV_NAME, .of_match_table = of_match_ptr(stm32_dcmi_of_match), + .pm = &dcmi_pm_ops, }, }; -- 2.7.4