drivers/powercom-hid.c: add Output section shutdown for RPT/BNT-AP series

Some Powercom UPS models (e.g. RPT-800AP, BNT-AP) experience
unreliable shutdown.return behavior when using the PowerSummary
section (UPS.PowerSummary.DelayBeforeShutdown, ReportID 0x0f).
While the initial shutdown command works, after several
shutdown.return cycles the UPS fails to restart and remains in
a powered-off state instead of turning back on.

Comparison with the vendor's UPSMON PRO software behavior (by
reading back register values via NUT debug mode) revealed that
the vendor software uses the Output section register
(UPS.Output.DelayBeforeShutdown, ReportID 0x23) instead. This 8-bit register accepts a discrete delay index (1-18)
per the protocol specification:

  Index  1   2   3   4   5   6   7   8   9  10  11  12  13  14  15  16  17  18
  Value 12s 18s 24s 30s 36s 42s 48s 54s  1m  2m  3m  4m  5m  6m  7m  8m  9m 10m

Using the Output section register provides reliable shutdown.return
behavior across repeated cycles.

This commit adds:

- powercom_shutdown_output_nuf(): converts offdelay seconds to the
  nearest discrete delay index for the Output section register.

- shutdown.return and shutdown.stayoff command mappings via
  UPS.Output.DelayBeforeShutdown, placed before the existing
  PowerSummary mappings so they take priority on affected models.

The existing PowerSummary shutdown commands are preserved as fallback
for models that use them (e.g. SKP, IMP, VGD series).

Note: the Output section shutdown is silent, unlike the PowerSummary
shutdown which produces audible warning beeps (double short beeps)
during the countdown before powering off.

Tested on: Powercom RPT-800AP (VendorID 0x0d9f, ProductID 0x0004)

Signed-off-by: Vladyslav Andreichykov <vladdrako007@gmail.com>

Author: Vladdrako

drivers/powercom-hid.c

@@ -241,6 +241,66 @@ static info_lkp_t powercom_shutdown_info[] = {
 	{ 0, NULL, powercom_shutdown_fun, powercom_shutdown_nuf }
 };
 
+/* Output section shutdown: uses discrete delay index (1-18) for
+ * UPS.Output.DelayBeforeShutdown (ReportID 0x23, 8-bit).
+ * Some Powercom UPS models (e.g. RPT-800AP, BNT-AP series) handle
+ * shutdown more reliably via the Output section registers than via
+ * PowerSummary. The native UPSMON PRO software uses these registers.
+ *
+ * Delay index table (from protocol spec):
+ *   Index  1   2   3   4   5   6   7   8   9  10  11  12  13  14  15  16  17  18
+ *   Value 12s 18s 24s 30s 36s 42s 48s 54s  1m  2m  3m  4m  5m  6m  7m  8m  9m 10m
+ */
+static double powercom_shutdown_output_nuf(const char *value)
+{
+	const char	*s = dstate_getinfo("ups.delay.shutdown");
+	const char	*cfg = getval("offdelay");
+	int iv;
+	uint8_t command;
+
+	if (value && *value)
+		iv = atoi(value);
+	else if (cfg && *cfg)
+		iv = atoi(cfg);
+	else if (s && *s)
+		iv = atoi(s);
+	else
+		iv = 60;
+
+	/* Convert seconds to discrete delay index per protocol spec */
+	if (iv <= 12)		command = 1;
+	else if (iv <= 18)	command = 2;
+	else if (iv <= 24)	command = 3;
+	else if (iv <= 30)	command = 4;
+	else if (iv <= 36)	command = 5;
+	else if (iv <= 42)	command = 6;
+	else if (iv <= 48)	command = 7;
+	else if (iv <= 54)	command = 8;
+	else if (iv <= 60)	command = 9;
+	else if (iv <= 120)	command = 10;
+	else if (iv <= 180)	command = 11;
+	else if (iv <= 240)	command = 12;
+	else if (iv <= 300)	command = 13;
+	else if (iv <= 360)	command = 14;
+	else if (iv <= 420)	command = 15;
+	else if (iv <= 480)	command = 16;
+	else if (iv <= 540)	command = 17;
+	else			command = 18;
+
+	upsdebugx(3, "%s: offdelay=%d -> discrete index=%d (ReportID 0x23)",
+		__func__, iv, command);
+
+	return (double)command;
+}
+
+static info_lkp_t powercom_shutdown_output_info[] = {
+	{ 0, NULL, powercom_shutdown_fun, powercom_shutdown_output_nuf }
+};
+
+static info_lkp_t powercom_stayoff_output_info[] = {
+	{ 0, NULL, NULL, powercom_shutdown_output_nuf }
+};
+
 static double powercom_stayoff_nuf(const char *value)
 {
 	const char	*s = dstate_getinfo("ups.delay.shutdown");
@@ -657,6 +717,9 @@ static hid_info_t powercom_hid2nut[] = {
 	{ "beeper.enable", 0, 0, "UPS.PowerSummary.AudibleAlarmControl", NULL, "1", HU_TYPE_CMD, NULL },
 	{ "beeper.disable", 0, 0, "UPS.PowerSummary.AudibleAlarmControl", NULL, "0", HU_TYPE_CMD, NULL },
 	{ "test.battery.start.quick", 0, 0, "UPS.Battery.Test", NULL, "1", HU_TYPE_CMD, NULL },
+	/* Output section shutdown (more reliable on RPT/BNT-AP series) */
+	{ "shutdown.return", 0, 0, "UPS.Output.DelayBeforeShutdown", NULL, NULL, HU_TYPE_CMD, powercom_shutdown_output_info },
+	{ "shutdown.stayoff", 0, 0, "UPS.Output.DelayBeforeShutdown", NULL, NULL, HU_TYPE_CMD, powercom_stayoff_output_info },
 	{ "load.on.delay", 0, 0, "UPS.PowerSummary.DelayBeforeStartup", NULL, NULL, HU_TYPE_CMD, powercom_startup_info },
 	{ "shutdown.return", 0, 0, "UPS.PowerSummary.DelayBeforeShutdown", NULL, NULL, HU_TYPE_CMD, powercom_shutdown_info },
 	{ "shutdown.stayoff", 0, 0, "UPS.PowerSummary.DelayBeforeShutdown", NULL, NULL, HU_TYPE_CMD, powercom_stayoff_info },