greybus: interface: move vendor and product strings to control device

The control device is an abstraction of the control connection over
which a greybus manifest is retrieved. As interfaces switch modes (e.g.
after boot-over-unipro) they expose new manifests, which can contain
different vendor and product strings.

Eventually control devices will be deregistered and recreated after an
interface mode switch, while the interface itself remains registered.

Note that only interfaces of type greybus will have control devices.
Specifically, dummy interfaces will not.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/drivers/staging/greybus/control.c b/drivers/staging/greybus/control.c
index 6063619..58a3d60 100644
--- a/drivers/staging/greybus/control.c
+++ b/drivers/staging/greybus/control.c
@@ -213,12 +213,40 @@ int gb_control_timesync_authoritative(struct gb_control *control,
 				 NULL, 0);
 }
 
+static ssize_t vendor_string_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct gb_control *control = to_gb_control(dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%s\n", control->vendor_string);
+}
+static DEVICE_ATTR_RO(vendor_string);
+
+static ssize_t product_string_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct gb_control *control = to_gb_control(dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%s\n", control->product_string);
+}
+static DEVICE_ATTR_RO(product_string);
+
+static struct attribute *control_attrs[] = {
+	&dev_attr_vendor_string.attr,
+	&dev_attr_product_string.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(control);
+
 static void gb_control_release(struct device *dev)
 {
 	struct gb_control *control = to_gb_control(dev);
 
 	gb_connection_destroy(control->connection);
 
+	kfree(control->vendor_string);
+	kfree(control->product_string);
+
 	kfree(control);
 }
 
@@ -249,6 +277,7 @@ struct gb_control *gb_control_create(struct gb_interface *intf)
 	control->dev.parent = &intf->dev;
 	control->dev.bus = &greybus_bus_type;
 	control->dev.type = &greybus_control_type;
+	control->dev.groups = control_groups;
 	control->dev.dma_mask = intf->dev.dma_mask;
 	device_initialize(&control->dev);
 	dev_set_name(&control->dev, "%s.ctrl", dev_name(&intf->dev));