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authorPierre-Yves MORDRET <pierre-yves.mordret@st.com>2020-01-28 10:41:55 +0100
committerVinod Koul <vkoul@kernel.org>2020-02-24 22:22:43 +0530
commitf65c2e14b096736585aa04cb7a43d5d54d287ddd (patch)
tree1cbbffc5ba946d2d009590ce8b92d34c94ed15e4 /drivers/dma/stm32-dmamux.c
parentdfc708812a2acfc0ca56f56233b3c3e7b0d4ffe7 (diff)
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>
Diffstat (limited to 'drivers/dma/stm32-dmamux.c')
-rw-r--r--drivers/dma/stm32-dmamux.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/drivers/dma/stm32-dmamux.c b/drivers/dma/stm32-dmamux.c
index 3c89bd39e096..08d2395c8943 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)
};