media: xilinx: multi-scaler: Add clock framework support

The Video Multi-Scaler has only one clock domain and
AXI Lite and AXI Stream interface both run on same clock.
This patch adds support to control this clock via clock framework.

By introducing these changes, the backward compatibility is broken
between DT and driver. So, it is mandatory to take new DT with
latest driver.

Signed-off-by: Suresh Gupta <suresh.gupta@xilinx.com>
Reviewed-by: Vishal Sagar <vishal.sagar@xilinx.com>
Reviewed-by: Hyun Kwon <hyun.kwon@xilinx.com>

drivers/media/platform/xilinx/xilinx-multi-scaler.c

@@ -12,6 +12,7 @@
  * Scaler Controller
  */
 
+#include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/fs.h>
 #include <linux/gpio/consumer.h>
@@ -327,6 +328,7 @@ struct xm2msc_chan_ctx {
  * @dev: pointer to struct device instance used by the driver
  * @regs: IO mapped base address of the HW/IP
  * @irq: interrupt number
+ * @clk: video core clock
  * @max_chan: maximum number of Scaling Channels
  * @max_ht: maximum number of rows in a plane
  * @max_wd: maximum number of column in a plane
@@ -354,6 +356,7 @@ struct xm2m_msc_dev {
 	struct device *dev;
 	void __iomem *regs;
 	int irq;
+	struct clk *clk;
 	u32 max_chan;
 	u32 max_ht;
 	u32 max_wd;
@@ -2011,6 +2014,13 @@ static int xm2msc_parse_of(struct platform_device *pdev,
 	int ret;
 	u32 i, j;
 
+	xm2msc->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(xm2msc->clk)) {
+		ret = PTR_ERR(xm2msc->clk);
+		dev_err(dev, "failed to get clk (%d)\n", ret);
+		return ret;
+	}
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	xm2msc->regs = devm_ioremap_resource(dev, res);
 	if (IS_ERR((__force void *)xm2msc->regs))
@@ -2173,13 +2183,19 @@ static int xm2m_msc_probe(struct platform_device *pdev)
 
 	xm2msc->dev = &pdev->dev;
 
+	ret = clk_prepare_enable(xm2msc->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable clk (%d)\n", ret);
+		return ret;
+	}
+
 	xm2msc_reset(xm2msc);
 
 	spin_lock_init(&xm2msc->lock);
 
 	ret = v4l2_device_register(&pdev->dev, &xm2msc->v4l2_dev);
 	if (ret)
-		return ret;
+		goto reg_dev_err;
 
 	for (chan = 0; chan < xm2msc->max_chan; chan++) {
 		chan_ctx = &xm2msc->xm2msc_chan[chan];
@@ -2244,6 +2260,8 @@ static int xm2m_msc_probe(struct platform_device *pdev)
  unreg_dev:
 	xm2msc_unreg_video_n_m2m(xm2msc);
 	v4l2_device_unregister(&xm2msc->v4l2_dev);
+reg_dev_err:
+	clk_disable_unprepare(xm2msc->clk);
 	return ret;
 }
 
@@ -2253,6 +2271,7 @@ static int xm2m_msc_remove(struct platform_device *pdev)
 
 	xm2msc_unreg_video_n_m2m(xm2msc);
 	v4l2_device_unregister(&xm2msc->v4l2_dev);
+	clk_disable_unprepare(xm2msc->clk);
 	return 0;
 }