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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 <pierre-yves.mordret@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200128094158.20361-2-amelie.delaunay@st.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Pierre-Yves MORDRET 2020-01-28 10:41:55 +01:00 committed by Vinod Koul
parent dfc708812a
commit f65c2e14b0
1 changed files with 50 additions and 0 deletions
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50
drivers/dma/stm32-dmamux.c
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@ -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)
};