greybus: svc: support status in svc_intf_activate response

Update per Greybus spec. Status attribute added to activate
response to return more detailed information about errors during
activate. If the Greybus response is GB_OP_SUCCESS, the caller
must also check the status attribute in the response to determine
if any other errors occurred.

Testing done: along with matchine firmware change, verified that modules
              were detected and enumerated as expected.
Signed-off-by: Jeffrey Carlyle <jcarlyle@google.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/staging/greybus/greybus_protocols.h

@@ -849,6 +849,24 @@ struct gb_spi_transfer_response {
 #define GB_SVC_TYPE_INTF_ACTIVATE		0x27
 #define GB_SVC_TYPE_INTF_MAILBOX_EVENT		0x29
 
+/* Greybus SVC protocol status values */
+#define GB_SVC_OP_SUCCESS			0x00
+#define GB_SVC_OP_UNKNOWN_ERROR			0x01
+#define GB_SVC_INTF_NOT_DETECTED		0x02
+#define GB_SVC_INTF_NO_UPRO_LINK		0x03
+#define GB_SVC_INTF_UPRO_NOT_DOWN		0x04
+#define GB_SVC_INTF_UPRO_NOT_HIBERNATED		0x05
+#define GB_SVC_INTF_NO_V_SYS			0x06
+#define GB_SVC_INTF_V_CHG			0x07
+#define GB_SVC_INTF_WAKE_BUSY			0x08
+#define GB_SVC_INTF_NO_REFCLK			0x09
+#define GB_SVC_INTF_RELEASING			0x0a
+#define GB_SVC_INTF_NO_ORDER			0x0b
+#define GB_SVC_INTF_MBOX_SET			0x0c
+#define GB_SVC_INTF_BAD_MBOX			0x0d
+#define GB_SVC_INTF_OP_TIMEOUT			0x0e
+#define GB_SVC_PWRMON_OP_NOT_PRESENT		0x0f
+
 struct gb_svc_version_request {
 	__u8	major;
 	__u8	minor;
@@ -1133,6 +1151,7 @@ struct gb_svc_intf_activate_request {
 #define GB_SVC_INTF_TYPE_GREYBUS		0x03
 
 struct gb_svc_intf_activate_response {
+	__u8	status;
 	__u8	intf_type;
 } __packed;
 

drivers/staging/greybus/svc.c

@@ -340,6 +340,11 @@ int gb_svc_intf_activate(struct gb_svc *svc, u8 intf_id, u8 *intf_type)
 			SVC_INTF_ACTIVATE_TIMEOUT);
 	if (ret < 0)
 		return ret;
+	if (response.status != GB_SVC_OP_SUCCESS) {
+		dev_err(&svc->dev, "failed to activate interface %u: %u\n",
+				intf_id, response.status);
+		return -EREMOTEIO;
+	}
 
 	*intf_type = response.intf_type;