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Subject[RESEND PATCH v1 2/3] dmaengine: stm32-dmamux: Add PM Runtime support
Date
Use pm_runtime engine for clock management purpose.

Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
---
Version history:
v1:
* Initial
---
---
drivers/dma/stm32-dmamux.c | 58 +++++++++++++++++++++++++++++++++++++---------
1 file changed, 47 insertions(+), 11 deletions(-)

diff --git a/drivers/dma/stm32-dmamux.c b/drivers/dma/stm32-dmamux.c
index b922db9..a671191 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,
},
};

--
2.7.4
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