[PATCH 06/11] firmware: arm_scmi: Add mechanism to unpack message headers

Sudeep Holla
2019-07-08T15:47:53Z

In order to identify the message type when a response arrives, we need
a mechanism to unpack the message header similar to packing. Let's
add one.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
drivers/firmware/arm_scmi/driver.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index eb5a2f271806..b384c818d8dd 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -30,8 +30,14 @@
#include "common.h"

#define MSG_ID_MASK GENMASK(7, 0)
+#define MSG_XTRACT_ID(hdr) FIELD_GET(MSG_ID_MASK, (hdr))
#define MSG_TYPE_MASK GENMASK(9, 8)
+#define MSG_XTRACT_TYPE(hdr) FIELD_GET(MSG_TYPE_MASK, (hdr))
+#define MSG_TYPE_COMMAND 0
+#define MSG_TYPE_DELAYED_RESP 2
+#define MSG_TYPE_NOTIFICATION 3
#define MSG_PROTOCOL_ID_MASK GENMASK(17, 10)
+#define MSG_XTRACT_PROT_ID(hdr) FIELD_GET(MSG_PROTOCOL_ID_MASK, (hdr))
#define MSG_TOKEN_ID_MASK GENMASK(27, 18)
#define MSG_XTRACT_TOKEN(hdr) FIELD_GET(MSG_TOKEN_ID_MASK, (hdr))
#define MSG_TOKEN_MAX (MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1)
@@ -216,6 +222,18 @@ static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)
FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id);
}

+/**
+ * unpack_scmi_header() - unpacks and records message and protocol id
+ *
+ * @msg_hdr: 32-bit packed message header sent from the platform
+ * @hdr: pointer to header to fetch message and protocol id.
+ */
+static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr)
+{
+ hdr->id = MSG_XTRACT_ID(msg_hdr);
+ hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr);
+}
+
/**
* scmi_tx_prepare() - mailbox client callback to prepare for the transfer
*
--
2.17.1