On 06/10/2011 05:22 PM, Grant Likely wrote:
On Fri, Jun 10, 2011 at 03:48:42PM -0500, Rob Herring wrote:
From: Rob Herring<[email protected]>
Add a function to create amba bus devices (i.e. primecell peripherals) from
device tree nodes. The device tree scanning is done by
of_platform_probe/populate functions which can call of_amba_device_create
based on a match table entry.
Nodes with a "arm,amba-deviceid" property can override the h/w peripheral id
value.
Based on the original work by Jeremy Kerr.
Cc: Jeremy Kerr<[email protected]>
Cc: Grant Likely<[email protected]>
Cc: [email protected]
Cc: [email protected]
Acked-by: Linus Walleij<[email protected]>
Signed-off-by: Rob Herring<[email protected]>
---
Documentation/devicetree/bindings/arm/amba.txt | 21 ++++++++++
drivers/amba/bus.c | 51 ++++++++++++++++++++++++
include/linux/amba/bus.h | 18 ++++++++
3 files changed, 90 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/arm/amba.txt
diff --git a/Documentation/devicetree/bindings/arm/amba.txt
b/Documentation/devicetree/bindings/arm/amba.txt
new file mode 100644
index 0000000..23fde7f
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/amba.txt
@@ -0,0 +1,21 @@
+* ARM Primecell Peripherals
+
+ARM, Ltd. Primecell peripherals have a standard id register that can be used to
+identify the peripheral type, vendor, and revision. This value can be used for
+driver matching.
+
+Required properties:
+
+- compatible : should be a specific value for peripheral and "arm,amba-device"
After recent conversations, I'd like to change this to
"arm,primecell" to better reflect the kind of devices it models.
That did cross my mind as I was writing the doc...
+
+Optional properties:
+
+- arm,amba-deviceid : Value to override the h/w value with
Similarly, based on the primecell device documents, this should
probabaly be arm,primecell-periphid.
+
+Example:
+
+serial@fff36000 {
+ compatible = "arm,pl011", "arm,amba-device";
+ arm,amba-deviceid =<0x00341011>;
+};
+
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index d74926e..19f712b 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -13,6 +13,11 @@
#include<linux/string.h>
#include<linux/slab.h>
#include<linux/io.h>
+#include<linux/of.h>
+#include<linux/of_irq.h>
+#include<linux/of_address.h>
+#include<linux/of_device.h>
+#include<linux/of_platform.h>
#include<linux/pm.h>
#include<linux/pm_runtime.h>
#include<linux/amba/bus.h>
@@ -785,3 +790,49 @@ EXPORT_SYMBOL(amba_device_unregister);
EXPORT_SYMBOL(amba_find_device);
EXPORT_SYMBOL(amba_request_regions);
EXPORT_SYMBOL(amba_release_regions);
+
+#ifdef CONFIG_OF
+int of_amba_device_create(struct device_node *node, struct device *parent)
+{
+ struct amba_device *dev;
+ const void *prop;
+ int i, ret;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+
+ /* setup generic device info */
+ dev->dev.coherent_dma_mask = ~0;
+ dev->dev.of_node = node;
+ dev->dev.parent = parent;
+ of_device_make_bus_id(&dev->dev);
+
+ /* setup amba-specific device info */
+ dev->dma_mask = ~0;
+
+ /* Allow the arm,amba-deviceid value to override the h/w value */
+ prop = of_get_property(node, "arm,amba-deviceid", 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 0;
+
+err_free:
+ kfree(dev);
+ return ret;
+}
+
Yeah, I think this looks like the right thing to do. I'll pick it up
into devicetree/test and probably move it to devicetree/arm in the
near future after testing a bit.
Okay, I'll respin with your and Arnd's comments.
Rob
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