Add some documentation to pulse demodulators

Hopefully this will help potential driver writers

include/pulse_demod.h

@@ -25,6 +25,9 @@
 /// The presence of a pulse is:
 /// - Presence of a pulse equals 1
 /// - Absence of a pulse equals 0
+/// @param device->short_limit: Nominal width of pulse [samples]
+/// @param device->long_limit:  Nominal width of bit period [samples]
+/// @param device->reset_limit: Maximum gap size before End Of Message [samples].
 /// @return number of events processed
 int pulse_demod_pcm_rz(const pulse_data_t *pulses, struct protocol_state *device);
 
@@ -36,6 +39,9 @@ int pulse_demod_pcm_rz(const pulse_data_t *pulses, struct protocol_state *device
 /// Gap between pulses determine the encoding:
 /// - Short gap will add a 0 bit
 /// - Long  gap will add a 1 bit
+/// @param device->short_limit: Threshold between short and long gap [samples]
+/// @param device->long_limit:  Maximum gap size before new row of bits [samples]
+/// @param device->reset_limit: Maximum gap size before End Of Message [samples].
 /// @return number of events processed
 int pulse_demod_ppm(const pulse_data_t *pulses, struct protocol_state *device);
 
@@ -46,6 +52,9 @@ int pulse_demod_ppm(const pulse_data_t *pulses, struct protocol_state *device);
 /// Gap between pulses may be of fixed size or variable (e.g. fixed period)
 /// - Short pulse will add a 1 bit
 /// - Long  pulse will add a 0 bit
+/// @param device->short_limit: Threshold between short and long pulse [samples]
+/// @param device->long_limit:  Maximum gap size before new row of bits [samples]
+/// @param device->reset_limit: Maximum gap size before End Of Message [samples].
 /// @param device->demod_arg = 0: Do not remove any startbits
 /// @param device->demod_arg = 1: First bit in each message is considered a startbit and not stored in bitbuffer
 /// @return number of events processed
@@ -57,6 +66,9 @@ int pulse_demod_pwm(const pulse_data_t *pulses, struct protocol_state *device);
 /// Demodulate a Pulse Width Modulation (PWM) signal consisting of short, middle and long high pulses.
 /// Gap between pulses may be of fixed size or variable (e.g. fixed period)
 /// The sync bit will add a new row to the bitbuffer
+/// @param device->short_limit: Threshold between short and middle pulse [samples]
+/// @param device->long_limit:  Threshold between middle and long pulse [samples]
+/// @param device->reset_limit: Maximum gap size before End Of Message [samples].
 /// @param device->demod_arg = 0: Short pulse is sync, middle is 0, long is 1
 /// @param device->demod_arg = 1: Short pulse is 0, middle is sync, long is 1
 /// @param device->demod_arg = 2: Short pulse is 0, middle is 1, long is sync
@@ -73,6 +85,9 @@ int pulse_demod_pwm_ternary(const pulse_data_t *pulses, struct protocol_state *d
 /// than 1.5 times the clock half period (short_width) it is declared a data edge where:
 /// - Rising edge means bit = 0
 /// - Falling edge means bit = 1
+/// @param device->short_limit: Nominal width of clock half period [samples]
+/// @param device->long_limit:  Not used
+/// @param device->reset_limit: Maximum gap size before End Of Message [samples].
 /// @return number of events processed
 int pulse_demod_manchester_zerobit(const pulse_data_t *pulses, struct protocol_state *device);