diff --git a/common/memory.c b/common/memory.c
index c564550..57c73ab 100644
--- a/common/memory.c
+++ b/common/memory.c
@@ -124,8 +124,8 @@
 	struct device_d *dev;
 
 	bank->res = request_iomem_region(name, start, start + size - 1);
-	if (!bank->res)
-		return -EBUSY;
+	if (IS_ERR(bank->res))
+		return PTR_ERR(bank->res);
 
 	dev = add_mem_device(name, start, size, IORESOURCE_MEM_WRITEABLE);
 
diff --git a/common/resource.c b/common/resource.c
index 6e84bd8..fd04f26 100644
--- a/common/resource.c
+++ b/common/resource.c
@@ -125,13 +125,7 @@
 struct resource *request_iomem_region(const char *name,
 		resource_size_t start, resource_size_t end)
 {
-	struct resource *res;
-
-	res = __request_region(&iomem_resource, name, start, end);
-	if (IS_ERR(res))
-		return NULL;
-
-	return res;
+	return __request_region(&iomem_resource, name, start, end);
 }
 
 /* The root resource for the whole io-mapped io space */
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index 6106252..b934e11 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -7,6 +7,7 @@
 #include <common.h>
 #include <driver.h>
 #include <linux/clk.h>
+#include <linux/err.h>
 #include <linux/amba/bus.h>
 #include <io.h>
 #include <init.h>
@@ -115,8 +116,8 @@
 	 */
 	size = resource_size(&dev->res);
 	res = request_iomem_region("amba", dev->res.start, dev->res.end);
-	if (!res)
-		return -ENOMEM;
+	if (IS_ERR(res))
+		return PTR_ERR(res);
 	dev->base = tmp = (void __force __iomem *)res->start;
 	if (!tmp) {
 		ret = -ENOMEM;
diff --git a/drivers/ata/intf_platform_ide.c b/drivers/ata/intf_platform_ide.c
index b3faf47..db4c356 100644
--- a/drivers/ata/intf_platform_ide.c
+++ b/drivers/ata/intf_platform_ide.c
@@ -28,6 +28,7 @@
 #include <errno.h>
 #include <ata_drive.h>
 #include <platform_ide.h>
+#include <linux/err.h>
 
 /**
  * Setup the register specific addresses for an ATA like divice
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index e39a351..d90da42 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -311,7 +311,7 @@
 		return NULL;
 
 	res = request_iomem_region(dev_name(dev), res->start, res->end);
-	if (!res)
+	if (IS_ERR(res))
 		return NULL;
 
 	return (void __force __iomem *)res->start;
@@ -327,7 +327,7 @@
 		return NULL;
 
 	res = request_iomem_region(dev_name(dev), res->start, res->end);
-	if (!res)
+	if (IS_ERR(res))
 		return NULL;
 
 	return (void __force __iomem *)res->start;
diff --git a/drivers/gpio/gpio-generic.c b/drivers/gpio/gpio-generic.c
index eeb4b42..1524a33 100644
--- a/drivers/gpio/gpio-generic.c
+++ b/drivers/gpio/gpio-generic.c
@@ -15,6 +15,7 @@
 #include <malloc.h>
 #include <linux/err.h>
 #include <linux/log2.h>
+#include <linux/err.h>
 #include <linux/basic_mmio_gpio.h>
 
 static void bgpio_write8(void __iomem *reg, unsigned int data)
@@ -321,8 +322,8 @@
 	}
 
 	ret = request_iomem_region(dev_name(dev), r->start, r->end);
-	if (!ret) {
-		*err = -ENOMEM;
+	if (IS_ERR(ret)) {
+		*err = PTR_ERR(ret);
 		return NULL;
 	}
 
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index 55cc34f..231f4fe 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -77,9 +77,9 @@
 	}
 
 	res = request_iomem_region(dev_name(dev), res->start, res->end);
-	if (!res) {
+	if (IS_ERR(res)) {
 		free(syscon);
-		return -EBUSY;
+		return PTR_ERR(res);
 	}
 
 	syscon->base = (void __iomem *)res->start;
diff --git a/drivers/pinctrl/pinctrl-rockchip.c b/drivers/pinctrl/pinctrl-rockchip.c
index 56377ea..a5b52a8 100644
--- a/drivers/pinctrl/pinctrl-rockchip.c
+++ b/drivers/pinctrl/pinctrl-rockchip.c
@@ -341,10 +341,10 @@
 	}
 
 	res = request_iomem_region(dev_name(dev), node_res.start, node_res.end);
-	if (!res) {
+	if (IS_ERR(res)) {
 		dev_err(dev, "cannot request iomem region %08x\n",
 			node_res.start);
-		return -ENOENT;
+		return PTR_ERR(res);
 	}
 
 	bank->reg_base = (void __iomem *)res->start;