dmaengine: sh: rz-dmac: Add DMA clock handling

Currently, DMA clocks are turned on by the bootloader.
This patch adds support for DMA clock handling so that
the driver manages the DMA clocks.

Fixes: 5000d37 ("dmaengine: sh: Add DMAC driver for RZ/G2L SoC")
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20210923102451.11403-1-biju.das.jz@bp.renesas.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/sh/rz-dmac.c

@@ -18,6 +18,7 @@
 #include <linux/of_dma.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 
@@ -872,6 +873,13 @@ static int rz_dmac_probe(struct platform_device *pdev)
 	/* Initialize the channels. */
 	INIT_LIST_HEAD(&dmac->engine.channels);
 
+	pm_runtime_enable(&pdev->dev);
+	ret = pm_runtime_resume_and_get(&pdev->dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "pm_runtime_resume_and_get failed\n");
+		goto err_pm_disable;
+	}
+
 	for (i = 0; i < dmac->n_channels; i++) {
 		ret = rz_dmac_chan_probe(dmac, &dmac->channels[i], i);
 		if (ret < 0)
@@ -925,6 +933,10 @@ static int rz_dmac_probe(struct platform_device *pdev)
 				  channel->lmdesc.base_dma);
 	}
 
+	pm_runtime_put(&pdev->dev);
+err_pm_disable:
+	pm_runtime_disable(&pdev->dev);
+
 	return ret;
 }
 
@@ -943,6 +955,8 @@ static int rz_dmac_remove(struct platform_device *pdev)
 	}
 	of_dma_controller_free(pdev->dev.of_node);
 	dma_async_device_unregister(&dmac->engine);
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
 
 	return 0;
 }