From: Mirela Rabulea <redacted>

Save some power by disabling/enabling the jpeg clocks with
every stream stop/start.

Signed-off-by: Mirela Rabulea <redacted>
---
 drivers/media/platform/imx-jpeg/mxc-jpeg.c | 79 +++++++++++++++++++++-
 drivers/media/platform/imx-jpeg/mxc-jpeg.h |  2 +
 2 files changed, 80 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/imx-jpeg/mxc-jpeg.c b/drivers/media/platform/imx-jpeg/mxc-jpeg.c
index 73e73b6f2e5b..2e1fef88cdf0 100644
--- a/drivers/media/platform/imx-jpeg/mxc-jpeg.c
+++ b/drivers/media/platform/imx-jpeg/mxc-jpeg.c

@@ -49,6 +49,7 @@
 #include <linux/slab.h>
 #include <linux/irqreturn.h>
 #include <linux/interrupt.h>
+#include <linux/pm_runtime.h>
 #include <linux/pm_domain.h>
 #include <linux/string.h>
 

@@ -1058,10 +1059,17 @@ static int mxc_jpeg_start_streaming(struct vb2_queue *q, unsigned int count)
 {
 	struct mxc_jpeg_ctx *ctx = vb2_get_drv_priv(q);
 	struct mxc_jpeg_q_data *q_data = mxc_jpeg_get_q_data(ctx, q->type);
+	int ret;
 
 	dev_dbg(ctx->mxc_jpeg->dev, "Start streaming ctx=%p", ctx);
 	q_data->sequence = 0;
 
+	ret = pm_runtime_get_sync(ctx->mxc_jpeg->dev);

+	if (ret < 0) {
+		dev_err(ctx->mxc_jpeg->dev, "Failed to power up jpeg\n");
+		return ret;
+	}
+
 	return 0;
 }
 

@@ -1079,9 +1087,10 @@ static void mxc_jpeg_stop_streaming(struct vb2_queue *q)
 		else
 			vbuf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
 		if (!vbuf)
-			return;
+			break;
 		v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR);
 	}
+	pm_runtime_put_sync(&ctx->mxc_jpeg->pdev->dev);
 }
 
 static int mxc_jpeg_valid_comp_id(struct device *dev,

@@ -1461,6 +1470,12 @@ static int mxc_jpeg_open(struct file *file)
 		goto free;
 	}
 
+	ret = pm_runtime_get_sync(mxc_jpeg->dev);

+	if (ret < 0) {
+		dev_err(ctx->mxc_jpeg->dev, "Failed to power up jpeg\n");
+		goto error_pm;
+	}
+
 	v4l2_fh_init(&ctx->fh, mxc_vfd);
 	file->private_data = &ctx->fh;
 	v4l2_fh_add(&ctx->fh);

@@ -1487,8 +1502,10 @@ static int mxc_jpeg_open(struct file *file)
 	return 0;
 
 error:
+	pm_runtime_put_sync(mxc_jpeg->dev);
 	v4l2_fh_del(&ctx->fh);
 	v4l2_fh_exit(&ctx->fh);
+error_pm:
 	mutex_unlock(&mxc_jpeg->lock);
 free:
 	kfree(ctx);

@@ -1875,6 +1892,7 @@ static int mxc_jpeg_release(struct file *file)
 	v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
 	v4l2_fh_del(&ctx->fh);
 	v4l2_fh_exit(&ctx->fh);
+	pm_runtime_put_sync(mxc_jpeg->dev);
 	kfree(ctx);
 	mutex_unlock(&mxc_jpeg->lock);
 

@@ -2005,6 +2023,19 @@ static int mxc_jpeg_probe(struct platform_device *pdev)
 	jpeg->dev = dev;
 	jpeg->mode = mode;
 
+	/* Get clocks */
+	jpeg->clk_ipg = devm_clk_get(dev, "ipg");
+	if (IS_ERR(jpeg->clk_ipg)) {
+		dev_err(dev, "failed to get clock: ipg\n");
+		goto err_clk;
+	}
+
+	jpeg->clk_per = devm_clk_get(dev, "per");
+	if (IS_ERR(jpeg->clk_per)) {
+		dev_err(dev, "failed to get clock: per\n");
+		goto err_clk;
+	}
+
 	ret = mxc_jpeg_attach_pm_domains(jpeg);
 	if (ret < 0) {
 		dev_err(dev, "failed to attach power domains %d\n", ret);

@@ -2073,6 +2104,7 @@ static int mxc_jpeg_probe(struct platform_device *pdev)
 			  jpeg->dec_vdev->minor);
 
 	platform_set_drvdata(pdev, jpeg);
+	pm_runtime_enable(dev);
 
 	return 0;
 

@@ -2089,9 +2121,52 @@ static int mxc_jpeg_probe(struct platform_device *pdev)
 	mxc_jpeg_detach_pm_domains(jpeg);
 
 err_irq:
+err_clk:
 	return ret;
 }
 
+#ifdef CONFIG_PM
+static int mxc_jpeg_runtime_resume(struct device *dev)
+{
+	struct mxc_jpeg_dev *jpeg = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(jpeg->clk_ipg);
+	if (ret < 0) {
+		dev_err(dev, "failed to enable clock: ipg\n");
+		goto err_ipg;
+	}
+
+	ret = clk_prepare_enable(jpeg->clk_per);
+	if (ret < 0) {
+		dev_err(dev, "failed to enable clock: per\n");
+		goto err_per;
+	}
+
+	return 0;
+
+err_per:
+	clk_disable_unprepare(jpeg->clk_ipg);
+err_ipg:
+	return ret;
+}
+
+static int mxc_jpeg_runtime_suspend(struct device *dev)
+{
+	struct mxc_jpeg_dev *jpeg = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(jpeg->clk_ipg);
+	clk_disable_unprepare(jpeg->clk_per);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops	mxc_jpeg_pm_ops = {
+	SET_RUNTIME_PM_OPS(mxc_jpeg_runtime_suspend,
+			   mxc_jpeg_runtime_resume, NULL)
+};
+
 static int mxc_jpeg_remove(struct platform_device *pdev)
 {
 	unsigned int slot;

@@ -2100,6 +2175,7 @@ static int mxc_jpeg_remove(struct platform_device *pdev)
 	for (slot = 0; slot < MXC_MAX_SLOTS; slot++)
 		mxc_jpeg_free_slot_data(jpeg, slot);
 
+	pm_runtime_disable(&pdev->dev);
 	video_unregister_device(jpeg->dec_vdev);
 	v4l2_m2m_release(jpeg->m2m_dev);
 	v4l2_device_unregister(&jpeg->v4l2_dev);

@@ -2116,6 +2192,7 @@ static struct platform_driver mxc_jpeg_driver = {
 	.driver = {
 		.name = "mxc-jpeg",
 		.of_match_table = mxc_jpeg_match,
+		.pm = &mxc_jpeg_pm_ops,
 	},
 };
 module_platform_driver(mxc_jpeg_driver);

diff --git a/drivers/media/platform/imx-jpeg/mxc-jpeg.h b/drivers/media/platform/imx-jpeg/mxc-jpeg.h
index 4c210852e876..9fb2a5aaa941 100644
--- a/drivers/media/platform/imx-jpeg/mxc-jpeg.h
+++ b/drivers/media/platform/imx-jpeg/mxc-jpeg.h

@@ -109,6 +109,8 @@ struct mxc_jpeg_dev {
 	spinlock_t			hw_lock; /* hardware access lock */
 	unsigned int			mode;
 	struct mutex			lock; /* v4l2 ioctls serialization */
+	struct clk			*clk_ipg;
+	struct clk			*clk_per;
 	struct platform_device		*pdev;
 	struct device			*dev;
 	void __iomem			*base_reg;