drivers/amba: create devices from device tree

Add a function to create amba_devices (i.e. primecell peripherals)
from device tree nodes. The device tree scanning is done by the
of_platform_populate() function which can call of_amba_device_create
based on a match table entry.

Nodes with a "arm,primecell-periphid" property can override the h/w
peripheral id value.

Based on the original work by Jeremy Kerr.

Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
[grant.likely: add Jeremy's original s-o-b line, changes from review
               comments, and moved all code to drivers/of/platform.c]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 71 insertions, 0 deletions

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 1f4a5d3af76e..4192ddc62638 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -13,6 +13,7 @@
  */
 #include <linux/errno.h>
 #include <linux/module.h>
+#include <linux/amba/bus.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
 #include <linux/slab.h>
@@ -217,6 +218,71 @@ struct platform_device *of_platform_device_create(struct device_node *np,
 }
 EXPORT_SYMBOL(of_platform_device_create);
 
+#ifdef CONFIG_ARM_AMBA
+static struct amba_device *of_amba_device_create(struct device_node *node,
+                                                 const char *bus_id,
+                                                 void *platform_data,
+                                                 struct device *parent)
+{
+        struct amba_device *dev;
+        const void *prop;
+        int i, ret;
+
+        pr_debug("Creating amba device %s\n", node->full_name);
+
+        if (!of_device_is_available(node))
+                return NULL;
+
+        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+        if (!dev)
+                return NULL;
+
+        /* setup generic device info */
+        dev->dev.coherent_dma_mask = ~0;
+        dev->dev.of_node = of_node_get(node);
+        dev->dev.parent = parent;
+        dev->dev.platform_data = platform_data;
+        if (bus_id)
+                dev_set_name(&dev->dev, "%s", bus_id);
+        else
+                of_device_make_bus_id(&dev->dev);
+
+        /* setup amba-specific device info */
+        dev->dma_mask = ~0;
+
+        /* Allow the HW Peripheral ID to be overridden */
+        prop = of_get_property(node, "arm,primecell-periphid", NULL);
+        if (prop)
+                dev->periphid = of_read_ulong(prop, 1);
+
+        /* Decode the IRQs and address ranges */
+        for (i = 0; i < AMBA_NR_IRQS; i++)
+                dev->irq[i] = irq_of_parse_and_map(node, i);
+
+        ret = of_address_to_resource(node, 0, &dev->res);
+        if (ret)
+                goto err_free;
+
+        ret = amba_device_register(dev, &iomem_resource);
+        if (ret)
+                goto err_free;
+
+        return dev;
+
+err_free:
+        kfree(dev);
+        return NULL;
+}
+#else /* CONFIG_ARM_AMBA */
+static struct amba_device *of_amba_device_create(struct device_node *node,
+                                                 const char *bus_id,
+                                                 void *platform_data,
+                                                 struct device *parent)
+{
+        return NULL;
+}
+#endif /* CONFIG_ARM_AMBA */
+
 /**
  * of_platform_bus_create() - Create a device for a node and its children.
  * @bus: device node of the bus to instantiate
@@ -242,6 +308,11 @@ static int of_platform_bus_create(struct device_node *bus,
                 return 0;
         }
 
+        if (of_device_is_compatible(bus, "arm,primecell")) {
+                of_amba_device_create(bus, NULL, NULL, parent);
+                return 0;
+        }
+
         dev = of_platform_device_create(bus, NULL, parent);
         if (!dev || !of_match_node(matches, bus))
                 return 0;