media: imx258: Fix getting clock frequency

Obtain the clock frequency by reading the clock-frequency property if
there's no clock.

Fixes: 9fda25332c4b ("media: i2c: imx258: get clock from device properties and enable it via runtime PM")
Signed-off-by: Sakari Ailus <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/i2c/imx258.c

···
 		return -ENOMEM;
 
 	imx258->clk = devm_clk_get_optional(&client->dev, NULL);
+	if (IS_ERR(imx258->clk))
+		return dev_err_probe(&client->dev, PTR_ERR(imx258->clk),
+				     "error getting clock\n");
 	if (!imx258->clk) {
 		dev_dbg(&client->dev,
 			"no clock provided, using clock-frequency property\n");
 
 		device_property_read_u32(&client->dev, "clock-frequency", &val);
-		if (val != IMX258_INPUT_CLOCK_FREQ)
-			return -EINVAL;
-	} else if (IS_ERR(imx258->clk)) {
-		return dev_err_probe(&client->dev, PTR_ERR(imx258->clk),
-				     "error getting clock\n");
+	} else {
+		val = clk_get_rate(imx258->clk);
 	}
-	if (clk_get_rate(imx258->clk) != IMX258_INPUT_CLOCK_FREQ) {
+	if (val != IMX258_INPUT_CLOCK_FREQ) {
 		dev_err(&client->dev, "input clock frequency not supported\n");
 		return -EINVAL;
 	}