hwmon: (aquacomputer_d5next) Add support for Octo flow sensor pulses

Add support for reading and writing the flow sensor pulses on
the Aquacomputer Octo. Implemented by David Flemstrom [1].

[1] https://github.com/aleksamagicka/aquacomputer_d5next-hwmon/pull/95

Originally-from: David Flemstrom <[e-mail]>
Signed-off-by: Aleksa Savic <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Guenter Roeck <[e-mail]>

Documentation/hwmon/aquacomputer_d5next.rst

···
 
 The Octo exposes four physical and sixteen virtual temperature sensors, a flow sensor
 as well as eight PWM controllable fans, along with their speed (in RPM), power, voltage
-and current.
+and current. Flow sensor pulses are also available.
 
 The Quadro exposes four physical and sixteen virtual temperature sensors, a flow
 sensor and four PWM controllable fans, along with their speed (in RPM), power,
···
 fan1_max         Maximal fan speed (in RPM)
 fan1_target      Target fan speed (in RPM)
 fan5_pulses      Quadro flow sensor pulses
+fan9_pulses      Octo flow sensor pulses
 power[1-8]_input Pump/fan power (in micro Watts)
 in[0-7]_input    Pump/fan voltage (in milli Volts)
 curr[1-8]_input  Pump/fan current (in milli Amperes)

drivers/hwmon/aquacomputer_d5next.c

···
 
 /* Control report offsets for the Octo */
 #define OCTO_TEMP_CTRL_OFFSET		0xA
+#define OCTO_FLOW_PULSES_CTRL_OFFSET	0x6
 /* Fan speed offsets (0-100%) */
 static u16 octo_ctrl_fan_offsets[] = { 0x5B, 0xB0, 0x105, 0x15A, 0x1AF, 0x204, 0x259, 0x2AE };
 
···
 			}
 			break;
 		case hwmon_fan_pulses:
-			/* Special case for Quadro flow sensor */
-			if (priv->kind == quadro && channel == priv->num_fans)
-				return 0644;
+			/* Special case for Quadro/Octo flow sensor */
+			if (channel == priv->num_fans) {
+				switch (priv->kind) {
+				case quadro:
+				case octo:
+					return 0644;
+				default:
+					break;
+				}
+			}
 			break;
 		case hwmon_fan_min:
 		case hwmon_fan_max:
···
 			   HWMON_F_INPUT | HWMON_F_LABEL,
 			   HWMON_F_INPUT | HWMON_F_LABEL,
 			   HWMON_F_INPUT | HWMON_F_LABEL,
-			   HWMON_F_INPUT | HWMON_F_LABEL),
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_PULSES),
 	HWMON_CHANNEL_INFO(power,
 			   HWMON_P_INPUT | HWMON_P_LABEL,
 			   HWMON_P_INPUT | HWMON_P_LABEL,
···
 		priv->buffer_size = OCTO_CTRL_REPORT_SIZE;
 		priv->ctrl_report_delay = CTRL_REPORT_DELAY;
 
+		priv->flow_pulses_ctrl_offset = OCTO_FLOW_PULSES_CTRL_OFFSET;
 		priv->power_cycle_count_offset = OCTO_POWER_CYCLES;
 
 		priv->temp_label = label_temp_sensors;