mfd: bcm2835-pm: Use 'reg-names' to get resources

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>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220625113619.15944-7-stefan.wahren@i2se.com

diff --git a/drivers/mfd/bcm2835-pm.c b/drivers/mfd/bcm2835-pm.c
index 42fe67f..418c8a1 100644 (file)
--- a/drivers/mfd/bcm2835-pm.c
+++ b/drivers/mfd/bcm2835-pm.c
@@ -25,9 +25,40 @@ 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 (of_find_property(pm->dev->of_node, "reg-names", NULL)) {
+               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;
+       }
+
+       /* If no 'reg-names' property is found we can assume we're using old DTB. */
+       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);
+       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 +70,9 @@ 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),
@@ -50,24 +80,15 @@ static int bcm2835_pm_probe(struct platform_device *pdev)
        if (ret)
                return ret;
 
-       /* We'll use the presence of the AXI ASB regs in the
+       /*
+        * We'll use the presence of the AXI ASB regs in the
         * 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;
 }