of: spmi: Add support for device naming and lookups
Since we support multiple device_nodes per spmi_device when used
with the spmi-dev-container flag, it's often unclear how a driver
should make reference to a particular device. Therefore,
introduce the spmi specific binding spmi-dev-name that specifies
the device name for the device_node.
Also introduce an API that can be used from
the driver to lookup the specific device node associated with a
particular device name.
Note that it may seem at first glance that the binding 'label' is
redundant with device_node->name. However, per the ePAPR,
device_node->name is intended to be as generic as possible,
representing the function of the device and not the precise
programming model. 'label' is used to give a platform
specific name that can be queried from device drivers.
Change-Id: I28eca35d0b625372c26a6d8ad81e7679f200d14b
Signed-off-by: Michael Bohan <mbohan@codeaurora.org>
diff --git a/drivers/spmi/spmi-resources.c b/drivers/spmi/spmi-resources.c
index 152b69d..390e9ec 100644
--- a/drivers/spmi/spmi-resources.c
+++ b/drivers/spmi/spmi-resources.c
@@ -119,3 +119,30 @@
return r ? r->start : -ENXIO;
}
EXPORT_SYMBOL_GPL(spmi_get_irq_byname);
+
+/*
+ * spmi_get_devnode_byname - get a device node resource
+ * @dev: spmi device handle
+ * @label: device name to lookup
+ *
+ * Given a name, find the associated spmi_resource that matches the name.
+ * Return NULL if the lookup fails.
+ */
+struct spmi_resource *spmi_get_dev_container_byname(struct spmi_device *dev,
+ const char *label)
+{
+ int i;
+
+ if (!label)
+ return NULL;
+
+ for (i = 0; i < dev->num_dev_node; i++) {
+ struct spmi_resource *r = &dev->dev_node[i];
+
+ if (r && r->label && !strncmp(r->label,
+ label, SPMI_MAX_RES_NAME))
+ return r;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(spmi_get_dev_container_byname);