complex data structure - please help

[aayu09]

I am working on a data structure, and I have difficulty understand it. Please see the following:

#define SAA7134_BOARD_KWORLD_ATSC115    0

struct saa7134_board {
	char                          *name;
	unsigned int            audio_clock;

	/* input switching */
	unsigned int            gpiomask;
	struct saa7134_input    inputs[SAA7134_INPUT_MAX];
	struct saa7134_input    radio;
	struct saa7134_input    mute;
	
	/* peripheral I/O */
	unsigned int            i2s_rate;
	unsigned int            has_ts;
	enum saa7134_video_out  video_out;

	/* i2c chip info */
	unsigned int		radio_type;
	unsigned char		tuner_addr;
	unsigned char		radio_addr;

	unsigned int            tda9887_conf;
	unsigned int            tuner_config;
	unsigned int 		tuner_type;
	
	/* peripheral I/O */
	enum saa7134_mpeg_type  mpeg;
	unsigned int            vid_port_opts;
};


struct saa7134_board saa7134_boards[] = {

                [SAA7134_BOARD_KWORLD_ATSC115] = {
		.name           = "Kworld ATSC115",
		.audio_clock    = 0x00187de7,
		.tuner_type     = TUNER_PHILIPS_TUV1236D,
		.radio_type     = UNSET,
		.tuner_addr     = ADDR_UNSET,
		.radio_addr     = ADDR_UNSET,
		.tda9887_conf   = TDA9887_PRESENT,
		.mpeg           = SAA7134_MPEG_DVB,
		.inputs         = {{
			.name = name_tv,
			.vmux = 1,
			.amux = TV,
			.tv   = 1,
		},{
			.name = name_comp1,
			.vmux = 3,
			.amux = LINE2,
		},{
			.name = name_svideo,
			.vmux = 8,

			.amux = LINE2,
		}},
	}
};

I have difficulty understand the last data structure, especially the "[SAA7134_BOARD_KWORLD_ATSC115] = {", what does this mean?

Any help will be appreciated.

[tabstop]

Do you see the define at the top? That means that everytime you see SAA7134_BOARD_KWORLD_ATSC115, it means "0".

[aayu09]

I saw that, but not sure I understand that. Is that equivalent to:

struct saa7134_board saa7134_boards[0] = {
		.name           = "Kworld ATSC115",
		.audio_clock    = 0x00187de7,
		.tuner_type     = TUNER_PHILIPS_TUV1236D,
		.radio_type     = UNSET,
		.tuner_addr     = ADDR_UNSET,
		.radio_addr     = ADDR_UNSET,
		.tda9887_conf   = TDA9887_PRESENT,
		.mpeg           = SAA7134_MPEG_DVB,
		.inputs         = {{
			.name = name_tv,
			.vmux = 1,
			.amux = TV,
			.tv   = 1,
		},{
			.name = name_comp1,
			.vmux = 3,
			.amux = LINE2,
		},{
			.name = name_svideo,
			.vmux = 8,

			.amux = LINE2,
		}}
};

Thanks again.

[Adak]

No, it's a very literal replacement by the pre processor. Only the words inside the square brackets, would be replaced by 0.

The brackets were not included in the #define.

I'm not sure what sense that makes, but there you have it.

[tabstop]

So you're sort of asking two questions there. The 0 wouldn't go there, it would go literally where the ALLCAPSCONSTANT was. But there's a compiler extension/C99 feature that allows you to initialize in that not-quite-as-awkward-as-it-looks syntax:

int array_with_not_many_elements[200] = 
    { [0] = 5, [17] = 3, [185] = 4 };

[aayu09]

Now I got it. Thanks for the help.