dddvb/docs/modulator_mci_api

MCI API for modulators:

Note:

stream - refers to one modulator slot which take a TS and modulates it
         e.g. the FSM16 has 16 streams

channel - an actual frequency the stream is sent on
          the FSM cards in default config have 96 channels at 114 MHz + X * 8 MHz (X=0-95)


MCI commands can be sent to modulators with the IOCTL_DDB_MCI_CMD:

#define IOCTL_DDB_MCI_CMD    _IOWR(DDB_MAGIC, 0x0c, struct ddb_mci_msg)

with

struct ddb_mci_msg {
	__u32 link;
	struct mci_command cmd;
	struct mci_result res;
};

link is always 0 for modulators.

mci_command with the entries relevant to modulators looks like this:

struct mci_command {
	union {
		u32 command_word;
		struct {
			u8 command;
			u8 tuner;
			u8 demod;
			u8 output;
		};
		struct {
			u8 mod_command;
			u8 mod_channel;
			u8 mod_stream;
			u8 mod_rsvd1;
		};
	};
	union {
	        ...
		struct mod_setup_channels mod_setup_channels[4];
		struct mod_setup_stream mod_setup_stream;
		struct mod_setup_output mod_setup_output;
		...
		};		    
};

mci_result like this:

struct mci_result {
	union {
		u32 status_word;
		struct {
			u8  status;
			u8  mode;
			u16 time;
		};
	};
	...

};



mci_command.command can be one of:

#define MOD_SETUP_CHANNELS        (0x60)
#define MOD_SETUP_OUTPUT          (0x61)
#define MOD_SETUP_STREAM          (0x62)

which use the following corresponding structs in mci_command:



MOD_SETUP_CHANNELS:

mod_command = MOD_SETUP_CHANNELS
mod_channel and mod_stream are not used


struct mod_setup_channels {
	u8   flags;
	u8   standard;
	u8   num_channels;
	u8   rsvd;
	u32  frequency;
	u32  offset;            /* used only when Standard == 0 */
	u32  bandwidth;         /* used only when Standard == 0 */
};

You can set up to 4 regions of channels.

flags:
#define MOD_SETUP_FLAG_FIRST      (0x01)
#define MOD_SETUP_FLAG_LAST       (0x02)
#define MOD_SETUP_FLAG_VALID      (0x80)

Set first/last if this is the first and/or last region you define.
Set valid if you actually want to set it.


standard:

see MOD_STANDARD_* defines in ddbridge-mci.h
for FSM cards only MOD_STANDARD_DVBC_6/7/8 are relevant


num_channels:

number of channels in this channel region


frequency:

start frquency of this region
frequency offset between channels depends on standard (e.g. 8MHz for DVBC_8)


offset/bandwidth: set offsets between channels and bandwidth by hand (not for FSM cards)



MOD_SETUP_OUTPUT:

set mod_command to MOD_SETUP_OUTPUT
mod_channel and mod_stream are not used


struct mod_setup_output {
	u8   connector;         /* 0 = OFF, 1 = F, 2 = SMA */
	u8   num_channels;      /* max active channels, determines max power for each channel. */
	u8   unit;              /* 0 = dBµV, 1 = dBm, */
	u8   rsvd;
	s16  channel_power;
};

connector:         use the F- or SMA-connector (the FSM cards only has F)

num_channels:      how many channels will have actually have a stream using it (has to be less or equal to card stream capability)
                   This influences internal multipliers. Setting it lower improves signal quality.


unit:              determines unit of channel_power (0 = dBµV, 1 = dBm)

channel_power:     set channel power of output to X dBµV or dBm.



MOD_SETUP_STREAM:


mod_command =   MOD_SETUP_STREAM
mod_stream  =   stream you want to configure
mod_channel =   channel the stream is to be sent on


struct mod_setup_stream {
	u8   standard;
	u8   stream_format;
	u8   rsvd1[2];
	u32  symbol_rate;        /* only used when Standard doesn't define a fixed symbol rate */
	union {
		struct mod_ofdm_parameter ofdm;
		struct mod_qam_parameter qam;
	};
};