[PATCH linux dev-5.1] OCC: FSI and hwmon: Add sequence numbering

[Eddie James <eajames@linux.ibm.com>]

Sequence numbering of the commands submitted to the OCC is required by
the OCC interface specification. Add sequence numbering and check for
the correct sequence number on the response.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/fsi/fsi-occ.c      | 15 ++++++++++++---
 drivers/hwmon/occ/common.c |  4 ++--
 drivers/hwmon/occ/common.h |  1 +
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/fsi/fsi-occ.c b/drivers/fsi/fsi-occ.c
index a2301ce..7da9c81 100644
--- a/drivers/fsi/fsi-occ.c
+++ b/drivers/fsi/fsi-occ.c
@@ -412,6 +412,7 @@ int fsi_occ_submit(struct device *dev, const void *request, size_t req_len,
 		msecs_to_jiffies(OCC_CMD_IN_PRG_WAIT_MS);
 	struct occ *occ = dev_get_drvdata(dev);
 	struct occ_response *resp = response;
+	u8 seq_no;
 	u16 resp_data_length;
 	unsigned long start;
 	int rc;
@@ -426,6 +427,8 @@ int fsi_occ_submit(struct device *dev, const void *request, size_t req_len,
 
 	mutex_lock(&occ->occ_lock);
 
+	/* Extract the seq_no from the command (first byte) */
+	seq_no = *(const u8 *)request;
 	rc = occ_putsram(occ, OCC_SRAM_CMD_ADDR, request, req_len);
 	if (rc)
 		goto done;
@@ -441,11 +444,17 @@ int fsi_occ_submit(struct device *dev, const void *request, size_t req_len,
 		if (rc)
 			goto done;
 
-		if (resp->return_status == OCC_RESP_CMD_IN_PRG) {
+		if (resp->return_status == OCC_RESP_CMD_IN_PRG ||
+		    resp->seq_no != seq_no) {
 			rc = -ETIMEDOUT;
 
-			if (time_after(jiffies, start + timeout))
-				break;
+			if (time_after(jiffies, start + timeout)) {
+				dev_err(occ->dev, "resp timeout status=%02x "
+					"resp seq_no=%d our seq_no=%d\n",
+					resp->return_status, resp->seq_no,
+					seq_no);
+				goto done;
+			}
 
 			set_current_state(TASK_UNINTERRUPTIBLE);
 			schedule_timeout(wait_time);
diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c
index d7cc0d2..e9d7167 100644
--- a/drivers/hwmon/occ/common.c
+++ b/drivers/hwmon/occ/common.c
@@ -122,12 +122,12 @@ struct extended_sensor {
 static int occ_poll(struct occ *occ)
 {
 	int rc;
-	u16 checksum = occ->poll_cmd_data + 1;
+	u16 checksum = occ->poll_cmd_data + occ->seq_no + 1;
 	u8 cmd[8];
 	struct occ_poll_response_header *header;
 
 	/* big endian */
-	cmd[0] = 0;			/* sequence number */
+	cmd[0] = occ->seq_no++;		/* sequence number */
 	cmd[1] = 0;			/* cmd type */
 	cmd[2] = 0;			/* data length msb */
 	cmd[3] = 1;			/* data length lsb */
diff --git a/drivers/hwmon/occ/common.h b/drivers/hwmon/occ/common.h
index fc13f3c..67e6968 100644
--- a/drivers/hwmon/occ/common.h
+++ b/drivers/hwmon/occ/common.h
@@ -95,6 +95,7 @@ struct occ {
 	struct occ_sensors sensors;
 
 	int powr_sample_time_us;	/* average power sample time */
+	u8 seq_no;
 	u8 poll_cmd_data;		/* to perform OCC poll command */
 	int (*send_cmd)(struct occ *occ, u8 *cmd);
 
-- 
1.8.3.1