staging: clocking-wizard: Allow changing of parent rate for single output

If there is only one output then allow changing of the parent rate.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1614172241-17326-5-git-send-email-shubhrajyoti.datta@xilinx.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/clocking-wizard/clk-xlnx-clock-wizard.c

@@ -138,6 +138,7 @@ static int clk_wzrd_probe(struct platform_device *pdev)
 	void __iomem *ctrl_reg;
 	struct clk_wzrd *clk_wzrd;
 	struct device_node *np = pdev->dev.of_node;
+	int nr_outputs;
 	unsigned long flags = 0;
 
 	clk_wzrd = devm_kzalloc(&pdev->dev, sizeof(*clk_wzrd), GFP_KERNEL);
@@ -201,6 +202,14 @@ static int clk_wzrd_probe(struct platform_device *pdev)
 		goto err_disable_clk;
 	}
 
+	ret = of_property_read_u32(np, "nr-outputs", &nr_outputs);
+	if (ret || nr_outputs > WZRD_NUM_OUTPUTS) {
+		ret = -EINVAL;
+		goto err_disable_clk;
+	}
+	if (nr_outputs == 1)
+		flags = CLK_SET_RATE_PARENT;
+
 	clk_wzrd->clks_internal[wzrd_clk_mul] = clk_register_fixed_factor
 			(&pdev->dev, clk_name,
 			 __clk_get_name(clk_wzrd->clk_in1),