[PATCH v3 6/8] drivers: provide devm_platform_ioremap_resource_byname()

[Bartosz Golaszewski <brgl@bgdev.pl>]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Provide a variant of devm_platform_ioremap_resource() that allows to
lookup resources from platform devices by name rather than by index.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 .../driver-api/driver-model/devres.rst        |  1 +
 drivers/base/platform.c                       | 20 +++++++++++++++++++
 include/linux/platform_device.h               |  3 +++
 3 files changed, 24 insertions(+)

diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index 480b78ca3871..4ab193319d8c 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -319,6 +319,7 @@ IOMAP
   devm_ioremap_resource_wc()
   devm_platform_ioremap_resource() : calls devm_ioremap_resource() for platform device
   devm_platform_ioremap_resource_wc()
+  devm_platform_ioremap_resource_byname()
   devm_iounmap()
   pcim_iomap()
   pcim_iomap_regions()	: do request_region() and iomap() on multiple BARs
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index d481b8a7d4fc..265d34253865 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -95,6 +95,26 @@ void __iomem *devm_platform_ioremap_resource_wc(struct platform_device *pdev,
 	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
 	return devm_ioremap_resource_wc(&pdev->dev, res);
 }
+
+/**
+ * devm_platform_ioremap_resource_byname - call devm_ioremap_resource for
+ *					   a platform device, retrieve the
+ *					   resource by name
+ *
+ * @pdev: platform device to use both for memory resource lookup as well as
+ *	  resource management
+ * @name: name of the resource
+ */
+void __iomem *
+devm_platform_ioremap_resource_byname(struct platform_device *pdev,
+				      const char *name)
+{
+	struct resource *res;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
+	return devm_ioremap_resource(&pdev->dev, res);
+}
+EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource_byname);
 #endif /* CONFIG_HAS_IOMEM */
 
 static int __platform_get_irq(struct platform_device *dev, unsigned int num)
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 83930790c701..fea5563f6fcf 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -60,6 +60,9 @@ devm_platform_ioremap_resource(struct platform_device *pdev,
 extern void __iomem *
 devm_platform_ioremap_resource_wc(struct platform_device *pdev,
 				  unsigned int index);
+extern void __iomem *
+devm_platform_ioremap_resource_byname(struct platform_device *pdev,
+				      const char *name);
 extern int platform_get_irq(struct platform_device *, unsigned int);
 extern int platform_get_irq_optional(struct platform_device *, unsigned int);
 extern int platform_irq_count(struct platform_device *);
-- 
2.23.0