greybus: clarify device vs module

The Project ARA MDK states that a single module can have more than
one interface block (up to 2 at the moment).  An interface block
consists of two bidirectional UniPro lanes (along with power and
detect lines), and effectively represents a UniPro Device (with
an id in the range 0-127).

The service messages currently use "module_id" everywhere, even
though in a lot of cases we really need to be talking about device
ids.  The easiest case of this to see is the "set route" request
directed at a switch; a switch has no notion of modules, just
UniPro devices.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

diff --git a/drivers/staging/greybus/svc_msg.h b/drivers/staging/greybus/svc_msg.h
index 986368d..1f8b4f1 100644 (file)
--- a/drivers/staging/greybus/svc_msg.h
+++ b/drivers/staging/greybus/svc_msg.h
@@ -48,14 +48,14 @@ struct svc_function_handshake {
 };
 
 struct svc_function_unipro_set_route {
-       __u8    source_module_id;
+       __u8    source_device_id;
        __u8    source_cport_id;        /* bottom 8 bits */
-       __u8    destination_module_id;
+       __u8    destination_device_id;
        __u8    destination_cport_id;   /* bottom 8 bits */
 };
 
 struct svc_function_unipro_link_up {
-       __u8    module_id;
+       __u8    device_id;
 };
 
 enum svc_function_management_event {
@@ -76,6 +76,11 @@ enum svc_function_hotplug_event {
        SVC_HOTUNPLUG_EVENT     = 0x01,
 };
 
+/* XXX
+ * Does a hotplug come from module insertion, or from detection
+ * of each interface block (UniPro device) in a module?  Assume
+ * the former for now.
+ */
 struct svc_function_hotplug {
        __u8    hotplug_event;  /* enum svc_function_hotplug_event */
        __u8    module_id;
@@ -87,6 +92,12 @@ enum svc_function_ddb_type {
        SVC_DDB_RESPONSE        = 0x01,
 };
 
+/* XXX
+ * Will only the first interface block in a module be responsible
+ * for this?  If a module has two interface blocks, will both supply
+ * the same information, or will it be partitioned?  For now assume
+ * it's a per-module thing.
+ */
 struct svc_function_ddb_get {
        __u8    module_id;
        __u8    message_id;
@@ -129,6 +140,11 @@ struct svc_function_power_battery_status {
 struct svc_function_power_battery_status_request {
 };
 
+/* XXX
+ * Each interface block carries power, so it's possible these things
+ * are associated with each UniPro device and not just the module.
+ * For now it's safe to assume it's per-module.
+ */
 struct svc_function_power {
        __u8    power_type;     /* enum svc_function_power_type */
        __u8    module_id;
@@ -143,6 +159,7 @@ enum svc_function_epm_command_type {
        SVC_EPM_DISABLE = 0x01,
 };
 
+/* EPM's are associated with the module */
 struct svc_function_epm {
        __u8    epm_command_type;       /* enum svc_function_epm_command_type */
        __u8    module_id;
@@ -153,9 +170,10 @@ enum svc_function_suspend_command_type {
        SVC_SUSPEND_FIXME_2     = 0x01,
 };
 
+/* We'll want independent control for multi-interface block modules */
 struct svc_function_suspend {
        __u8    suspend_command_type;   /* enum function_suspend_command_type */
-       __u8    module_id;
+       __u8    device_id;
 };
 
 struct svc_msg {