3 files changed, 155 insertions, 30 deletions

diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index 4903a408fc14..ba239b529fa9 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -23,6 +23,7 @@
 #include <linux/of_device.h>
 #include <linux/of_dma.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/reset.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
@@ -641,12 +642,13 @@ static irqreturn_t stm32_dma_chan_irq(int irq, void *devid)
 {
         struct stm32_dma_chan *chan = devid;
         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
-        u32 status, scr;
+        u32 status, scr, sfcr;
 
         spin_lock(&chan->vchan.lock);
 
         status = stm32_dma_irq_status(chan);
         scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
+        sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
 
         if (status & STM32_DMA_TCI) {
                 stm32_dma_irq_clear(chan, STM32_DMA_TCI);
@@ -661,10 +663,12 @@ static irqreturn_t stm32_dma_chan_irq(int irq, void *devid)
         if (status & STM32_DMA_FEI) {
                 stm32_dma_irq_clear(chan, STM32_DMA_FEI);
                 status &= ~STM32_DMA_FEI;
-                if (!(scr & STM32_DMA_SCR_EN))
-                        dev_err(chan2dev(chan), "FIFO Error\n");
-                else
-                        dev_dbg(chan2dev(chan), "FIFO over/underrun\n");
+                if (sfcr & STM32_DMA_SFCR_FEIE) {
+                        if (!(scr & STM32_DMA_SCR_EN))
+                                dev_err(chan2dev(chan), "FIFO Error\n");
+                        else
+                                dev_dbg(chan2dev(chan), "FIFO over/underrun\n");
+                }
         }
         if (status) {
                 stm32_dma_irq_clear(chan, status);
@@ -1112,15 +1116,14 @@ static int stm32_dma_alloc_chan_resources(struct dma_chan *c)
         int ret;
 
         chan->config_init = false;
-        ret = clk_prepare_enable(dmadev->clk);
-        if (ret < 0) {
-                dev_err(chan2dev(chan), "clk_prepare_enable failed: %d\n", ret);
+
+        ret = pm_runtime_get_sync(dmadev->ddev.dev);
+        if (ret < 0)
                 return ret;
-        }
 
         ret = stm32_dma_disable_chan(chan);
         if (ret < 0)
-                clk_disable_unprepare(dmadev->clk);
+                pm_runtime_put(dmadev->ddev.dev);
 
         return ret;
 }
@@ -1140,7 +1143,7 @@ static void stm32_dma_free_chan_resources(struct dma_chan *c)
                 spin_unlock_irqrestore(&chan->vchan.lock, flags);
         }
 
-        clk_disable_unprepare(dmadev->clk);
+        pm_runtime_put(dmadev->ddev.dev);
 
         vchan_free_chan_resources(to_virt_chan(c));
 }
@@ -1240,6 +1243,12 @@ static int stm32_dma_probe(struct platform_device *pdev)
                 return PTR_ERR(dmadev->clk);
         }
 
+        ret = clk_prepare_enable(dmadev->clk);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret);
+                return ret;
+        }
+
         dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
                                                 "st,mem2mem");
 
@@ -1289,7 +1298,7 @@ static int stm32_dma_probe(struct platform_device *pdev)
 
         ret = dma_async_device_register(dd);
         if (ret)
-                return ret;
+                goto clk_free;
 
         for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
                 chan = &dmadev->chan[i];
@@ -1321,20 +1330,58 @@ static int stm32_dma_probe(struct platform_device *pdev)
 
         platform_set_drvdata(pdev, dmadev);
 
+        pm_runtime_set_active(&pdev->dev);
+        pm_runtime_enable(&pdev->dev);
+        pm_runtime_get_noresume(&pdev->dev);
+        pm_runtime_put(&pdev->dev);
+
         dev_info(&pdev->dev, "STM32 DMA driver registered\n");
 
         return 0;
 
 err_unregister:
         dma_async_device_unregister(dd);
+clk_free:
+        clk_disable_unprepare(dmadev->clk);
 
         return ret;
 }
 
+#ifdef CONFIG_PM
+static int stm32_dma_runtime_suspend(struct device *dev)
+{
+        struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
+
+        clk_disable_unprepare(dmadev->clk);
+
+        return 0;
+}
+
+static int stm32_dma_runtime_resume(struct device *dev)
+{
+        struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
+        int ret;
+
+        ret = clk_prepare_enable(dmadev->clk);
+        if (ret) {
+                dev_err(dev, "failed to prepare_enable clock\n");
+                return ret;
+        }
+
+        return 0;
+}
+#endif
+
+static const struct dev_pm_ops stm32_dma_pm_ops = {
+        SET_RUNTIME_PM_OPS(stm32_dma_runtime_suspend,
+                           stm32_dma_runtime_resume, NULL)
+};
+
 static struct platform_driver stm32_dma_driver = {
         .driver = {
                 .name = "stm32-dma",
                 .of_match_table = stm32_dma_of_match,
+                .pm = &stm32_dma_pm_ops,
         },
 };
 
diff --git a/drivers/dma/stm32-dmamux.c b/drivers/dma/stm32-dmamux.c
index b922db90939a..a67119199c45 100644
--- a/drivers/dma/stm32-dmamux.c
+++ b/drivers/dma/stm32-dmamux.c
@@ -28,6 +28,7 @@
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/of_dma.h>
+#include <linux/pm_runtime.h>
 #include <linux/reset.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
@@ -79,8 +80,7 @@ static void stm32_dmamux_free(struct device *dev, void *route_data)
         stm32_dmamux_write(dmamux->iomem, STM32_DMAMUX_CCR(mux->chan_id), 0);
         clear_bit(mux->chan_id, dmamux->dma_inuse);
 
-        if (!IS_ERR(dmamux->clk))
-                clk_disable(dmamux->clk);
+        pm_runtime_put_sync(dev);
 
         spin_unlock_irqrestore(&dmamux->lock, flags);
 
@@ -146,13 +146,10 @@ static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec,
 
         /* Set dma request */
         spin_lock_irqsave(&dmamux->lock, flags);
-        if (!IS_ERR(dmamux->clk)) {
-                ret = clk_enable(dmamux->clk);
-                if (ret < 0) {
-                        spin_unlock_irqrestore(&dmamux->lock, flags);
-                        dev_err(&pdev->dev, "clk_prep_enable issue: %d\n", ret);
-                        goto error;
-                }
+        ret = pm_runtime_get_sync(&pdev->dev);
+        if (ret < 0) {
+                spin_unlock_irqrestore(&dmamux->lock, flags);
+                goto error;
         }
         spin_unlock_irqrestore(&dmamux->lock, flags);
 
@@ -254,6 +251,7 @@ static int stm32_dmamux_probe(struct platform_device *pdev)
                 dev_warn(&pdev->dev, "DMAMUX defaulting on %u requests\n",
                          stm32_dmamux->dmamux_requests);
         }
+        pm_runtime_get_noresume(&pdev->dev);
 
         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
         iomem = devm_ioremap_resource(&pdev->dev, res);
@@ -282,6 +280,8 @@ static int stm32_dmamux_probe(struct platform_device *pdev)
         stm32_dmamux->dmarouter.route_free = stm32_dmamux_free;
 
         platform_set_drvdata(pdev, stm32_dmamux);
+        pm_runtime_set_active(&pdev->dev);
+        pm_runtime_enable(&pdev->dev);
 
         if (!IS_ERR(stm32_dmamux->clk)) {
                 ret = clk_prepare_enable(stm32_dmamux->clk);
@@ -291,17 +291,52 @@ static int stm32_dmamux_probe(struct platform_device *pdev)
                 }
         }
 
+        pm_runtime_get_noresume(&pdev->dev);
+
         /* Reset the dmamux */
         for (i = 0; i < stm32_dmamux->dma_requests; i++)
                 stm32_dmamux_write(stm32_dmamux->iomem, STM32_DMAMUX_CCR(i), 0);
 
-        if (!IS_ERR(stm32_dmamux->clk))
-                clk_disable(stm32_dmamux->clk);
+        pm_runtime_put(&pdev->dev);
 
         return of_dma_router_register(node, stm32_dmamux_route_allocate,
                                      &stm32_dmamux->dmarouter);
 }
 
+#ifdef CONFIG_PM
+static int stm32_dmamux_runtime_suspend(struct device *dev)
+{
+        struct platform_device *pdev =
+                container_of(dev, struct platform_device, dev);
+        struct stm32_dmamux_data *stm32_dmamux = platform_get_drvdata(pdev);
+
+        clk_disable_unprepare(stm32_dmamux->clk);
+
+        return 0;
+}
+
+static int stm32_dmamux_runtime_resume(struct device *dev)
+{
+        struct platform_device *pdev =
+                container_of(dev, struct platform_device, dev);
+        struct stm32_dmamux_data *stm32_dmamux = platform_get_drvdata(pdev);
+        int ret;
+
+        ret = clk_prepare_enable(stm32_dmamux->clk);
+        if (ret) {
+                dev_err(&pdev->dev, "failed to prepare_enable clock\n");
+                return ret;
+        }
+
+        return 0;
+}
+#endif
+
+static const struct dev_pm_ops stm32_dmamux_pm_ops = {
+        SET_RUNTIME_PM_OPS(stm32_dmamux_runtime_suspend,
+                           stm32_dmamux_runtime_resume, NULL)
+};
+
 static const struct of_device_id stm32_dmamux_match[] = {
         { .compatible = "st,stm32h7-dmamux" },
         {},
@@ -312,6 +347,7 @@ static struct platform_driver stm32_dmamux_driver = {
         .driver = {
                 .name = "stm32-dmamux",
                 .of_match_table = stm32_dmamux_match,
+                .pm = &stm32_dmamux_pm_ops,
         },
 };
 
diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
index 390e4cae0e1a..4e0eede599a8 100644
--- a/drivers/dma/stm32-mdma.c
+++ b/drivers/dma/stm32-mdma.c
@@ -37,6 +37,7 @@
 #include <linux/of_device.h>
 #include <linux/of_dma.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/reset.h>
 #include <linux/slab.h>
 
@@ -1456,15 +1457,13 @@ static int stm32_mdma_alloc_chan_resources(struct dma_chan *c)
                 return -ENOMEM;
         }
 
-        ret = clk_prepare_enable(dmadev->clk);
-        if (ret < 0) {
-                dev_err(chan2dev(chan), "clk_prepare_enable failed: %d\n", ret);
+        ret = pm_runtime_get_sync(dmadev->ddev.dev);
+        if (ret < 0)
                 return ret;
-        }
 
         ret = stm32_mdma_disable_chan(chan);
         if (ret < 0)
-                clk_disable_unprepare(dmadev->clk);
+                pm_runtime_put(dmadev->ddev.dev);
 
         return ret;
 }
@@ -1484,7 +1483,7 @@ static void stm32_mdma_free_chan_resources(struct dma_chan *c)
                 spin_unlock_irqrestore(&chan->vchan.lock, flags);
         }
 
-        clk_disable_unprepare(dmadev->clk);
+        pm_runtime_put(dmadev->ddev.dev);
         vchan_free_chan_resources(to_virt_chan(c));
         dmam_pool_destroy(chan->desc_pool);
         chan->desc_pool = NULL;
@@ -1579,9 +1578,11 @@ static int stm32_mdma_probe(struct platform_device *pdev)
 
         dmadev->nr_channels = nr_channels;
         dmadev->nr_requests = nr_requests;
-        device_property_read_u32_array(&pdev->dev, "st,ahb-addr-masks",
+        ret = device_property_read_u32_array(&pdev->dev, "st,ahb-addr-masks",
                                        dmadev->ahb_addr_masks,
                                        count);
+        if (ret)
+                return ret;
         dmadev->nr_ahb_addr_masks = count;
 
         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -1597,6 +1598,12 @@ static int stm32_mdma_probe(struct platform_device *pdev)
                 return ret;
         }
 
+        ret = clk_prepare_enable(dmadev->clk);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret);
+                return ret;
+        }
+
         dmadev->rst = devm_reset_control_get(&pdev->dev, NULL);
         if (!IS_ERR(dmadev->rst)) {
                 reset_control_assert(dmadev->rst);
@@ -1668,6 +1675,10 @@ static int stm32_mdma_probe(struct platform_device *pdev)
         }
 
         platform_set_drvdata(pdev, dmadev);
+        pm_runtime_set_active(&pdev->dev);
+        pm_runtime_enable(&pdev->dev);
+        pm_runtime_get_noresume(&pdev->dev);
+        pm_runtime_put(&pdev->dev);
 
         dev_info(&pdev->dev, "STM32 MDMA driver registered\n");
 
@@ -1677,11 +1688,42 @@ err_unregister:
         return ret;
 }
 
+#ifdef CONFIG_PM
+static int stm32_mdma_runtime_suspend(struct device *dev)
+{
+        struct stm32_mdma_device *dmadev = dev_get_drvdata(dev);
+
+        clk_disable_unprepare(dmadev->clk);
+
+        return 0;
+}
+
+static int stm32_mdma_runtime_resume(struct device *dev)
+{
+        struct stm32_mdma_device *dmadev = dev_get_drvdata(dev);
+        int ret;
+
+        ret = clk_prepare_enable(dmadev->clk);
+        if (ret) {
+                dev_err(dev, "failed to prepare_enable clock\n");
+                return ret;
+        }
+
+        return 0;
+}
+#endif
+
+static const struct dev_pm_ops stm32_mdma_pm_ops = {
+        SET_RUNTIME_PM_OPS(stm32_mdma_runtime_suspend,
+                           stm32_mdma_runtime_resume, NULL)
+};
+
 static struct platform_driver stm32_mdma_driver = {
         .probe = stm32_mdma_probe,
         .driver = {
                 .name = "stm32-mdma",
                 .of_match_table = stm32_mdma_of_match,
+                .pm = &stm32_mdma_pm_ops,
         },
 };