memory: samsung: exynos5422-dmc: use scoped device node handling to simplify error paths

Obtain the device node reference with scoped/cleanup.h to reduce error
handling and make the code a bit simpler.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240816-cleanup-h-of-node-put-memory-v2-4-9eed0ee16b78@linaro.orgSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

drivers/memory/samsung/exynos5422-dmc.c

@@ -4,6 +4,7 @@
  * Author: Lukasz Luba <l.luba@partner.samsung.com>
  */
 
+#include <linux/cleanup.h>
 #include <linux/clk.h>
 #include <linux/devfreq.h>
 #include <linux/devfreq-event.h>
@@ -1178,10 +1179,10 @@ static int of_get_dram_timings(struct exynos5_dmc *dmc)
 	int ret = 0;
 	struct device *dev = dmc->dev;
 	int idx;
-	struct device_node *np_ddr;
 	u32 freq_mhz, clk_period_ps;
 
-	np_ddr = of_parse_phandle(dev->of_node, "device-handle", 0);
+	struct device_node *np_ddr __free(device_node) =
+		of_parse_phandle(dev->of_node, "device-handle", 0);
 	if (!np_ddr) {
 		dev_warn(dev, "could not find 'device-handle' in DT\n");
 		return -EINVAL;
@@ -1189,39 +1190,31 @@ static int of_get_dram_timings(struct exynos5_dmc *dmc)
 
 	dmc->timing_row = devm_kmalloc_array(dev, TIMING_COUNT,
 					     sizeof(u32), GFP_KERNEL);
-	if (!dmc->timing_row) {
-		ret = -ENOMEM;
-		goto put_node;
-	}
+	if (!dmc->timing_row)
+		return -ENOMEM;
 
 	dmc->timing_data = devm_kmalloc_array(dev, TIMING_COUNT,
 					      sizeof(u32), GFP_KERNEL);
-	if (!dmc->timing_data) {
-		ret = -ENOMEM;
-		goto put_node;
-	}
+	if (!dmc->timing_data)
+		return -ENOMEM;
 
 	dmc->timing_power = devm_kmalloc_array(dev, TIMING_COUNT,
 					       sizeof(u32), GFP_KERNEL);
-	if (!dmc->timing_power) {
-		ret = -ENOMEM;
-		goto put_node;
-	}
+	if (!dmc->timing_power)
+		return -ENOMEM;
 
 	dmc->timings = of_lpddr3_get_ddr_timings(np_ddr, dev,
 						 DDR_TYPE_LPDDR3,
 						 &dmc->timings_arr_size);
 	if (!dmc->timings) {
 		dev_warn(dev, "could not get timings from DT\n");
-		ret = -EINVAL;
-		goto put_node;
+		return -EINVAL;
 	}
 
 	dmc->min_tck = of_lpddr3_get_min_tck(np_ddr, dev);
 	if (!dmc->min_tck) {
 		dev_warn(dev, "could not get tck from DT\n");
-		ret = -EINVAL;
-		goto put_node;
+		return -EINVAL;
 	}
 
 	/* Sorted array of OPPs with frequency ascending */
@@ -1241,8 +1234,6 @@ static int of_get_dram_timings(struct exynos5_dmc *dmc)
 	dmc->bypass_timing_data = dmc->timing_data[idx - 1];
 	dmc->bypass_timing_power = dmc->timing_power[idx - 1];
 
-put_node:
-	of_node_put(np_ddr);
 	return ret;
 }