From f65c2e14b096736585aa04cb7a43d5d54d287ddd Mon Sep 17 00:00:00 2001 From: Pierre-Yves MORDRET Date: Tue, 28 Jan 2020 10:41:55 +0100 Subject: [PATCH] dmaengine: stm32-dmamux: add suspend/resume power management support Add suspend/resume power management relying on PM Runtime engine. Signed-off-by: Pierre-Yves MORDRET Signed-off-by: Amelie Delaunay Link: https://lore.kernel.org/r/20200128094158.20361-2-amelie.delaunay@st.com Signed-off-by: Vinod Koul --- drivers/dma/stm32-dmamux.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/drivers/dma/stm32-dmamux.c b/drivers/dma/stm32-dmamux.c index 3c89bd3..08d2395 100644 --- a/drivers/dma/stm32-dmamux.c +++ b/drivers/dma/stm32-dmamux.c @@ -41,6 +41,9 @@ struct stm32_dmamux_data { u32 dmamux_requests; /* Number of DMA requests routed toward DMAs */ spinlock_t lock; /* Protects register access */ unsigned long *dma_inuse; /* Used DMA channel */ + u32 ccr[STM32_DMAMUX_MAX_DMA_REQUESTS]; /* Used to backup CCR register + * in suspend + */ u32 dma_reqs[]; /* Number of DMA Request per DMA masters. * [0] holds number of DMA Masters. * To be kept at very end end of this structure @@ -318,7 +321,54 @@ static int stm32_dmamux_runtime_resume(struct device *dev) } #endif +#ifdef CONFIG_PM_SLEEP +static int stm32_dmamux_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct stm32_dmamux_data *stm32_dmamux = platform_get_drvdata(pdev); + int i, ret; + + ret = pm_runtime_get_sync(dev); + if (ret < 0) + return ret; + + for (i = 0; i < stm32_dmamux->dma_requests; i++) + stm32_dmamux->ccr[i] = stm32_dmamux_read(stm32_dmamux->iomem, + STM32_DMAMUX_CCR(i)); + + pm_runtime_put_sync(dev); + + pm_runtime_force_suspend(dev); + + return 0; +} + +static int stm32_dmamux_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct stm32_dmamux_data *stm32_dmamux = platform_get_drvdata(pdev); + int i, ret; + + ret = pm_runtime_force_resume(dev); + if (ret < 0) + return ret; + + ret = pm_runtime_get_sync(dev); + if (ret < 0) + return ret; + + for (i = 0; i < stm32_dmamux->dma_requests; i++) + stm32_dmamux_write(stm32_dmamux->iomem, STM32_DMAMUX_CCR(i), + stm32_dmamux->ccr[i]); + + pm_runtime_put_sync(dev); + + return 0; +} +#endif + static const struct dev_pm_ops stm32_dmamux_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(stm32_dmamux_suspend, stm32_dmamux_resume) SET_RUNTIME_PM_OPS(stm32_dmamux_runtime_suspend, stm32_dmamux_runtime_resume, NULL) }; -- 2.7.4