media: ti: j721e-csi2rx: Support runtime suspend

Add support for runtime power-management to enable powering off the
shared power domain between Cadence CSI2RX and TI CSI2RX wrapper when
the device(s) are not in use.

When powering off the IP, the PSI-L endpoint loses the paired DMA
channels. Thus we have to release the DMA channels at runtime suspend
and request them again at resume.

Tested-by: Rishikesh Donadkar <r-donadkar@ti.com>
Reviewed-by: Rishikesh Donadkar <r-donadkar@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
Co-developed-by: Rishikesh Donadkar <r-donadkar@ti.com>
Signed-off-by: Rishikesh Donadkar <r-donadkar@ti.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

2 files changed, 54 insertions, 3 deletions

diff --git a/drivers/media/platform/ti/Kconfig b/drivers/media/platform/ti/Kconfig
index da33facf4467..d0cb05481bd8 100644
--- a/drivers/media/platform/ti/Kconfig
+++ b/drivers/media/platform/ti/Kconfig
@@ -83,6 +83,7 @@ config VIDEO_TI_J721E_CSI2RX
 	depends on VIDEO_CADENCE_CSI2RX
 	depends on PHY_CADENCE_DPHY_RX || COMPILE_TEST
 	depends on ARCH_K3 || COMPILE_TEST
+	depends on PM
 	select VIDEOBUF2_DMA_CONTIG
 	select V4L2_FWNODE
 	help
diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
index 3142849f9bb9..d68b8d6ffeb1 100644
--- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
+++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/property.h>
 
 #include <media/cadence/cdns-csi2rx.h>
@@ -964,14 +965,18 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
 	struct ti_csi2rx_dev *csi = ctx->csi;
 	struct ti_csi2rx_dma *dma = &ctx->dma;
 	unsigned long flags;
-	int ret = 0;
+	int ret;
+
+	ret = pm_runtime_resume_and_get(csi->dev);
+	if (ret)
+		return ret;
 
 	spin_lock_irqsave(&dma->lock, flags);
 	if (list_empty(&dma->queue))
 		ret = -EIO;
 	spin_unlock_irqrestore(&dma->lock, flags);
 	if (ret)
-		return ret;
+		goto err;
 
 	ret = video_device_pipeline_start(&ctx->vdev, &csi->pipe);
 	if (ret)
@@ -993,6 +998,8 @@ err_dma:
 	writel(0, csi->shim + SHIM_DMACNTX(ctx->idx));
 err:
 	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_QUEUED);
+	pm_runtime_put(csi->dev);
+
 	return ret;
 }
 
@@ -1012,6 +1019,7 @@ static void ti_csi2rx_stop_streaming(struct vb2_queue *vq)
 
 	ti_csi2rx_stop_dma(ctx);
 	ti_csi2rx_cleanup_buffers(ctx, VB2_BUF_STATE_ERROR);
+	pm_runtime_put(csi->dev);
 }
 
 static const struct vb2_ops csi_vb2_qops = {
@@ -1257,7 +1265,9 @@ static void ti_csi2rx_cleanup_notifier(struct ti_csi2rx_dev *csi)
 
 static void ti_csi2rx_cleanup_ctx(struct ti_csi2rx_ctx *ctx)
 {
-	dma_release_channel(ctx->dma.chan);
+	if (!pm_runtime_status_suspended(ctx->csi->dev))
+		dma_release_channel(ctx->dma.chan);
+
 	vb2_queue_release(&ctx->vidq);
 
 	video_unregister_device(&ctx->vdev);
@@ -1507,6 +1517,38 @@ cleanup_dma:
 	return ret;
 }
 
+static int ti_csi2rx_runtime_suspend(struct device *dev)
+{
+	struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
+
+	if (csi->enable_count != 0)
+		return -EBUSY;
+
+	for (unsigned int i = 0; i < csi->num_ctx; i++)
+		dma_release_channel(csi->ctx[i].dma.chan);
+
+	return 0;
+}
+
+static int ti_csi2rx_runtime_resume(struct device *dev)
+{
+	struct ti_csi2rx_dev *csi = dev_get_drvdata(dev);
+	int ret;
+
+	for (unsigned int i = 0; i < csi->num_ctx; i++) {
+		ret = ti_csi2rx_init_dma(&csi->ctx[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops ti_csi2rx_pm_ops = {
+	RUNTIME_PM_OPS(ti_csi2rx_runtime_suspend, ti_csi2rx_runtime_resume,
+		       NULL)
+};
+
 static int ti_csi2rx_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
@@ -1562,6 +1604,9 @@ static int ti_csi2rx_probe(struct platform_device *pdev)
 			goto err_ctx;
 	}
 
+	pm_runtime_set_active(csi->dev);
+	pm_runtime_enable(csi->dev);
+
 	ret = ti_csi2rx_notifier_register(csi);
 	if (ret)
 		goto err_ctx;
@@ -1592,6 +1637,9 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
 	struct ti_csi2rx_dev *csi = platform_get_drvdata(pdev);
 	unsigned int i;
 
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		pm_runtime_set_suspended(&pdev->dev);
+
 	for (i = 0; i < csi->num_ctx; i++)
 		ti_csi2rx_cleanup_ctx(&csi->ctx[i]);
 
@@ -1599,6 +1647,7 @@ static void ti_csi2rx_remove(struct platform_device *pdev)
 	ti_csi2rx_cleanup_v4l2(csi);
 	dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr,
 			  csi->drain.paddr);
+	pm_runtime_disable(&pdev->dev);
 }
 
 static const struct of_device_id ti_csi2rx_of_match[] = {
@@ -1613,6 +1662,7 @@ static struct platform_driver ti_csi2rx_pdrv = {
 	.driver = {
 		.name = TI_CSI2RX_MODULE_NAME,
 		.of_match_table = ti_csi2rx_of_match,
+		.pm		= &ti_csi2rx_pm_ops,
 	},
 };