[PATCH V2 06/11] mfd: bcm2835-pm: Use 'reg-names' to get resources

[Stefan Wahren <stefan.wahren@i2se.com>]

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

If available in firmware, find resources by their 'reg-names' position
instead of relying on hardcoded offsets. Care is taken to support old
firmware nonetheless.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Peter Robinson <pbrobinson@gmail.com>
---
 drivers/mfd/bcm2835-pm.c | 59 +++++++++++++++++++++++++++-------------
 1 file changed, 40 insertions(+), 19 deletions(-)

diff --git a/drivers/mfd/bcm2835-pm.c b/drivers/mfd/bcm2835-pm.c
index 42fe67f1538e..c1e81a4541d7 100644
--- a/drivers/mfd/bcm2835-pm.c
+++ b/drivers/mfd/bcm2835-pm.c
@@ -25,9 +25,41 @@ static const struct mfd_cell bcm2835_power_devs[] = {
 	{ .name = "bcm2835-power" },
 };
 
+static int bcm2835_pm_get_pdata(struct platform_device *pdev,
+				struct bcm2835_pm *pm)
+{
+	/* If no 'reg-names' property is found we can assume we're using old
+	 * firmware.
+	 */
+	if (!of_find_property(pm->dev->of_node, "reg-names", NULL)) {
+		dev_warn(pm->dev, "reg-names are missing, please update your DTB.\n");
+
+		pm->base = devm_platform_ioremap_resource(pdev, 0);
+		if (IS_ERR(pm->base))
+			return PTR_ERR(pm->base);
+
+		pm->asb = devm_platform_ioremap_resource(pdev, 1);
+	} else {
+		struct resource *res;
+
+		pm->base = devm_platform_ioremap_resource_byname(pdev, "pm");
+		if (IS_ERR(pm->base))
+			return PTR_ERR(pm->base);
+
+		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+						    "asb");
+		if (res)
+			pm->asb = devm_ioremap_resource(&pdev->dev, res);
+	}
+
+	if (IS_ERR(pm->asb))
+		pm->asb = NULL;
+
+	return 0;
+}
+
 static int bcm2835_pm_probe(struct platform_device *pdev)
 {
-	struct resource *res;
 	struct device *dev = &pdev->dev;
 	struct bcm2835_pm *pm;
 	int ret;
@@ -39,10 +71,9 @@ static int bcm2835_pm_probe(struct platform_device *pdev)
 
 	pm->dev = dev;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	pm->base = devm_ioremap_resource(dev, res);
-	if (IS_ERR(pm->base))
-		return PTR_ERR(pm->base);
+	ret = bcm2835_pm_get_pdata(pdev, pm);
+	if (ret)
+		return ret;
 
 	ret = devm_mfd_add_devices(dev, -1,
 				   bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
@@ -54,20 +85,10 @@ static int bcm2835_pm_probe(struct platform_device *pdev)
 	 * bcm2835-pm binding as the key for whether we can reference
 	 * the full PM register range and support power domains.
 	 */
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-	if (res) {
-		pm->asb = devm_ioremap_resource(dev, res);
-		if (IS_ERR(pm->asb))
-			return PTR_ERR(pm->asb);
-
-		ret = devm_mfd_add_devices(dev, -1,
-					   bcm2835_power_devs,
-					   ARRAY_SIZE(bcm2835_power_devs),
-					   NULL, 0, NULL);
-		if (ret)
-			return ret;
-	}
-
+	if (pm->asb)
+		return devm_mfd_add_devices(dev, -1, bcm2835_power_devs,
+					    ARRAY_SIZE(bcm2835_power_devs),
+					    NULL, 0, NULL);
 	return 0;
 }
 
-- 
2.25.1