[PATCH 1/8] dmaengine: stm32-dma: add suspend/resume power management support
From: Amelie Delaunay <hidden>
Date: 2020-01-29 15:37:14
Also in:
linux-arm-kernel, lkml
Subsystem:
dma generic offload engine subsystem, the rest · Maintainers:
Vinod Koul, Linus Torvalds
From: Pierre-Yves MORDRET <redacted> Add suspend/resume power management relying on PM Runtime engine. Signed-off-by: Pierre-Yves MORDRET <redacted> Signed-off-by: Amelie Delaunay <redacted> --- drivers/dma/stm32-dma.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index 5989b0893521..136deabd1aa3 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c@@ -1427,7 +1427,39 @@ static int stm32_dma_runtime_resume(struct device *dev) } #endif +#ifdef CONFIG_PM_SLEEP +static int stm32_dma_suspend(struct device *dev) +{ + struct stm32_dma_device *dmadev = dev_get_drvdata(dev); + int id, ret, scr; + + ret = pm_runtime_get_sync(dev); + if (ret < 0) + return ret; + + for (id = 0; id < STM32_DMA_MAX_CHANNELS; id++) { + scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id)); + if (scr & STM32_DMA_SCR_EN) { + dev_warn(dev, "Suspend is prevented by Chan %i\n", id); + return -EBUSY; + } + } + + pm_runtime_put_sync(dev); + + pm_runtime_force_suspend(dev); + + return 0; +} + +static int stm32_dma_resume(struct device *dev) +{ + return pm_runtime_force_resume(dev); +} +#endif + static const struct dev_pm_ops stm32_dma_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(stm32_dma_suspend, stm32_dma_resume) SET_RUNTIME_PM_OPS(stm32_dma_runtime_suspend, stm32_dma_runtime_resume, NULL) };
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2.17.1