nvme-print: Decode Sample Rate Scale

Add human friendly decoded version of Sample Rate Scale (SRS)
of the Interval Power Measurement Sample Rate (IPMSR) field
in the Identify Controller Data Structure.

Signed-off-by: Jim Munn <[email protected]>

Author: jimmunn

nvme-print-stdout.c

@@ -2441,7 +2441,8 @@ static void stdout_id_ctrl_ipmsr(__le16 ctrl_ipmsr)
 	__u16 srs = NVME_GET(ipmsr, CTRL_IPMSR_SRS);
 	__u16 srv = NVME_GET(ipmsr, CTRL_IPMSR_SRV);
 
-	printf("  [15:8] : %#x\tSample Rate Scale\n", srs);
+	printf("  [15:8] : %#x\tSample Rate Scale (%s)\n", srs,
+		nvme_ipmsr_srs_to_string(srs));
 	printf("  [7:0]  : %#x\tSample Rate Value\n", srv);
 
 	printf("\n");

nvme-print.c

@@ -1580,6 +1580,26 @@ const char *nvme_power_measurement_action_to_string(__u8 act)
 	return "Reserved";
 }
 
+const char *nvme_ipmsr_srs_to_string(__u8 srs)
+{
+	switch (srs) {
+	case 0:
+		return "Not reported";
+	case 1:
+		return "1 microsecond";
+	case 2:
+		return "10 microseconds";
+	case 3:
+		return "100 microseconds";
+	case 4:
+		return "1 millisecond";
+	case 5:
+		return "10 milliseconds";
+	default:
+		return "Reserved";
+	}
+}
+
 void nvme_feature_show(enum nvme_features_id fid, int sel, unsigned int result)
 {
 	nvme_print(show_feature, NORMAL, fid, sel, result);

nvme-print.h

@@ -346,6 +346,7 @@ const char *nvme_bpwps_to_string(__u8 bpwps);
 const char *nvme_feature_power_limit_scale_to_string(__u8 pls);
 const char *nvme_power_measurement_type_to_string(__u8 pmt);
 const char *nvme_power_measurement_action_to_string(__u8 act);
+const char *nvme_ipmsr_srs_to_string(__u8 srs);
 
 void nvme_dev_full_path(nvme_ns_t n, char *path, size_t len);
 void nvme_generic_full_path(nvme_ns_t n, char *path, size_t len);