hw-mgmt: scripts: Add I2C bus ownership check and reporting for VMOD0021 systems.

Implement a check for I2C bus ownership on VMOD0021 systems to determine
if it is controlled by the CPU or BMC.
Typically, ownership should be with the CPU.
If not, report an error and try ownership enforcement to CPU.

Bug: 4597390
Signed-off-by: Michael Shych <michaelsh@nvidia.com>

Author: mshych

usr/usr/bin/hw-management.sh

@@ -2341,6 +2341,24 @@ smart_switch_common()
 
 n51xxld_specific()
 {
+	# Report I2C bus ownership for VMOD0021 systems at early initialization
+	bmc_to_cpu_ctrl_path=$(ls /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/bmc_to_cpu_ctrl 2>/dev/null | head -n1)
+	if [ -f "$bmc_to_cpu_ctrl_path" ]; then
+		bus_ownership=$(< "$bmc_to_cpu_ctrl_path")
+		if [ "$bus_ownership" = "0" ]; then
+			log_info "I2C bus ownership: CPU (bmc_to_cpu_ctrl=0)"
+		elif [ "$bus_ownership" = "1" ]; then
+			log_info "I2C bus ownership: BMC (bmc_to_cpu_ctrl=1)"
+			# Try to enforce ownership to CPU
+			echo 0 > /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/bmc_to_cpu_ctrl
+		else
+			# Should never happen as driver represents CPLD bit
+			log_err "I2C bus ownership: Unknown value (bmc_to_cpu_ctrl=$bus_ownership)"
+		fi
+	else
+		log_err "I2C bus ownership: bmc_to_cpu_ctrl file not found"
+	fi
+
 	local cpu_bus_offset=55
 	if [ ! -e "$devtree_file" ]; then
 		connect_table+=(${n5110ld_base_connect_table[@]})
@@ -2459,7 +2477,6 @@ n51xxld_specific()
 	mctp_bus="$n5110_mctp_bus"
 	mctp_addr="$n5110_mctp_addr"
 	ln -sf /dev/i2c-2 /dev/i2c-8
-	echo 0 > /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/bmc_to_cpu_ctrl
 }
 
 n51xxld_specific_cleanup()