[PATCH 02/16] device: Add a dev_request_mem_region function

[Jean-Christophe PLAGNIOL-VILLARD]

From: Sascha Hauer <s.hauer at pengutronix.de>

We might want to add real resource tracking later. Also
The first resource may not be a IORESOURCE_MEM at all.
For these reasons introduce a wrapper function for
driver so that they do not have to fiddle with resources
directly.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
---
 include/driver.h |   14 ++++++++++++++
 lib/driver.c     |   17 +++++++++++++++++
 2 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/include/driver.h b/include/driver.h
index ed3df16..0fc254d 100644
--- a/include/driver.h
+++ b/include/driver.h
@@ -188,6 +188,20 @@ static inline const char *dev_name(const struct device_d *dev)
 	return dev_id(dev);
 }
 
+/*
+ * get register base 'num' for a device
+ */
+void __iomem *dev_get_mem_region(struct device_d *dev, int num);
+
+/*
+ * exlusively request register base 'num' for a device
+ */
+static inline void __iomem *dev_request_mem_region(struct device_d *dev, int num)
+{
+	/* no resource tracking yet */
+	return dev_get_mem_region(dev, num);
+}
+
 /* linear list over all available devices
  */
 extern struct list_head device_list;
diff --git a/lib/driver.c b/lib/driver.c
index 95e42d5..b5166c8 100644
--- a/lib/driver.c
+++ b/lib/driver.c
@@ -233,6 +233,23 @@ int register_driver(struct driver_d *drv)
 }
 EXPORT_SYMBOL(register_driver);
 
+void __iomem *dev_get_mem_region(struct device_d *dev, int num)
+{
+	int i, n = 0;
+
+	for (i = 0; i < dev->num_resources; i++) {
+		struct resource *res = &dev->resource[i];
+		if (resource_type(res) == IORESOURCE_MEM) {
+			if (n == num)
+				return (void __force __iomem *)res->start;
+			n++;
+		}
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(dev_get_mem_region);
+
 int dev_protect(struct device_d *dev, size_t count, unsigned long offset, int prot)
 {
 	printf("%s: currently broken\n", __func__);
-- 
1.7.5.4