[linux-dvb] [PATCH] add DVB-S2 support to frontend.h

Manu Abraham abraham.manu at gmail.com
Sun Mar 5 16:38:19 CET 2006


Marcel Siegert wrote:
> this patch is adding dvb-s2 support to frontend.h
>
> From: Marcel Siegert <mws at linuxtv.org>
>
> changes:
> -------------------------------------------------------------------------------------------------- 
>
> added FE_DVB_S2 as new frontend type;
> renamed all other frontend types from modulation to system name;
> provided backwards compatibility defines for old apps;
> -------------------------------------------------------------------------------------------------- 
>
> added FE_CAN_DVB_S2 to fe_caps;
> added FE_HAS_EXTENDED_CAN_VALUES to fe_caps
>       - this flag set signals that new introduced ioctl 
> FE_GET_EXTENDED_INFO is available,
>         and fec / modulation / misc flags can be queried using it.
>
> to provide this functionallity i did a backport of API V4 enumerations.
> in detail these are
> - dvb_fe_code_rate
> - dvb_fe_modulation
> - dvb_fe_common_cap
> - dvb_fe_other_cap
>
> they give us plenty room for further upcoming modulations and features 
> that must be handled/queried.
>
> they have been modified to have the topmost value kept at 1<<31 so it 
> should be guaranteed,
> even if we add values, from start to end 32 bits will be used as 
> internal representation for the enums.
>
> they can be queried passing the FE_GET_EXTENDED_INFO a 
> dvb_fe_caps_extended struct;
> all 4 groups of enumerations are returned at once.
> as they were split up, we still have room for more enumeration values.
>
> there's still room to have e.g. FE_CAN_DVB_T2, FE_CAN_DVB_C2 within 
> the normal and wellknown
> fe_caps enumeration scheme.
> -------------------------------------------------------------------------------------------------- 
>
> added fe_rolloff_factor enumerations, they are needed by DVB-S2 tuning 
> parameters
> -------------------------------------------------------------------------------------------------- 
>
> renamed dvb_XXXX_parameters to match system not modulation type.
> added/provided backwards compatible defines
> renamed dvb_frontend_parameters struct names to match renamed 
> dvb_XXXX_parameters
> -------------------------------------------------------------------------------------------------- 
>
> added dvb_dvbs2_parameters struct to take dvb-s2 tuning parameters
> -------------------------------------------------------------------------------------------------- 
>
> added dvb_frontend_parameters_extended struct,
> this one will be used for dvb-s2 and upcoming tuning structs merged in 
> a union.
> -------------------------------------------------------------------------------------------------- 
>
> renamed dvb_frontend_parameters to __dvb_frontend_parameters_old;
> renamed ioctls: FE_SET_FRONTEND and FE_GET_FRONTEND to 
> __FE_SET_FRONTEND_OLD and __FE_GET_FRONTEND_OLD;
> this is done like in net.h to keep backwards binary compatibility.
> -------------------------------------------------------------------------------------------------- 
>
> added ioctls: FE_SET_FRONTEND and FE_GET_FRONTEND
> added struct: dvb_frontend_parameters, that are slightly different from
>  the renamed old ones. there a two fields added, type and a pointer to 
> the dvb_frontend_parameters_extended.
>  though it stored as a pointer we won't have any conflicts, like we 
> had with dvb-s2, in the future.
>
> for backwards source compatibility old struct is integrated in the new 
> one.
> -------------------------------------------------------------------------------------------------- 
>
> renamed dvb_frontend_event to __dvb_frontend_event_old
> as this keeps a struct with the __dvb_frontend_parameters_old
> -------------------------------------------------------------------------------------------------- 
>
> added dvb_frontend_event - binary compatibility through having same 
> first members
> as __dvb_frontend_event_old.
> added type flag and dvb_frontend_parameters_extended as a pointer for 
> the extended tuning data.
> first use is dvb-s2 (dvb_dvbs2_parameters struct);
> -------------------------------------------------------------------------------------------------- 
>
> added dvb_api_version struct, holding a each 16-bit wide major and 
> minor version.
> -------------------------------------------------------------------------------------------------- 
>
> added FE_GET_APIVERSION ioctl - query the actual kernel api version 
> using dvb_api_version struct.
> this is necessary to get the ability to write userspace 
> applications/encapsulations/libraries
> for different api versions that can handle changes and map between apis.
> -------------------------------------------------------------------------------------------------- 
>
> renamed FE_GET_EVENT ioctl to __FE_GET_EVENT_OLD
> backwards binary compatibility reasons (see above)
> -------------------------------------------------------------------------------------------------- 
>
> added FE_EXTENDED_TP (0x80) as fe_status_t enumeration flag.
> -------------------------------------------------------------------------------------------------- 
>
> added FE_GET_EVENT ioctl to receive a dvb_frontend_event struct. as 
> this one is
> source compatible to prior versions it signals via the FE_EXTENDED_TP 
> flag in fe_status_t, that a
> dvb_frontend_parameters_extended struct is also returned.
> to determine type of the extended struct (e.g. dvb-s2) the type was 
> also added as struct member.
> -------------------------------------------------------------------------------------------------- 
>
>
> that's it a least. i do know that is it more than a "workaround for 
> dvb-s2" and that it maybe seems
> to be ugly.
> i discussed long times on irc with felix, manu, andrew, and mike, how 
> to keep source and binary
> backwards compatibility. i hope i reached that.
>
> please do not hesitate to send comments if i missed a case.
>
> best regards
> marcel
>
>
> Signed-off-by: Marcel Siegert <mws at linuxtv.org>
> ------------------------------------------------------------------------
>
> --- ../../../../../../v4l-dvb/linux/include/linux/dvb/frontend.h	2006-02-27 01:36:46.117934750 +0100
> +++ frontend.h	2006-02-27 20:43:45.600403500 +0100
> @@ -30,12 +30,16 @@
>  
>  
>  typedef enum fe_type {
> -	FE_QPSK,
> -	FE_QAM,
> -	FE_OFDM,
> -	FE_ATSC
> +	FE_DVB_S,
> +	FE_DVB_C,
> +	FE_DVB_T,
> +	FE_ATSC,
> +	FE_DVB_S2
>  } fe_type_t;
>  
> +#define FE_QPSK	FE_DVB_S
> +#define FE_QAM	FE_DVB_C
> +#define FE_OFDM	FE_DVB_T
>  
>  typedef enum fe_caps {
>  	FE_IS_STUPID			= 0,
> @@ -62,12 +66,13 @@
>  	FE_CAN_HIERARCHY_AUTO		= 0x100000,
>  	FE_CAN_8VSB			= 0x200000,
>  	FE_CAN_16VSB			= 0x400000,
> +	FE_CAN_DVB_S2			= 0x1000000,
> +	FE_HAS_EXTENDED_CAN_VALUES	= 0x10000000,
>  	FE_NEEDS_BENDING		= 0x20000000, // not supported anymore, don't use (frontend requires frequency bending)
>  	FE_CAN_RECOVER			= 0x40000000, // frontend can recover from a cable unplug automatically
>  	FE_CAN_MUTE_TS			= 0x80000000  // frontend can stop spurious TS data output
>  } fe_caps_t;
>  
> -
>  struct dvb_frontend_info {
>  	char       name[128];
>  	fe_type_t  type;
> @@ -82,6 +87,69 @@
>  	fe_caps_t  caps;
>  };
>  
> +/* backport from dvb-api v4 - adapted a bit to have the last value at bit 31 so we */
> +/* guarantee that the enum will normally have 32 bits size */
> +/*! describes the available forward error correction code rates. */
> +enum dvb_fe_code_rate {
> +	DVB_FE_FEC_NONE = (1 << 0),
> +	DVB_FE_FEC_1_2  = (1 << 1),
> +	DVB_FE_FEC_2_3  = (1 << 2),
> +	DVB_FE_FEC_3_4  = (1 << 3),
> +	DVB_FE_FEC_4_5  = (1 << 4),
> +	DVB_FE_FEC_5_6  = (1 << 5),
> +	DVB_FE_FEC_6_7  = (1 << 6),
> +	DVB_FE_FEC_7_8  = (1 << 7),
> +	DVB_FE_FEC_8_9  = (1 << 8),
> +	DVB_FE_FEC_3_5	= (1 << 9),
> +	DVB_FE_FEC_9_10	= (1 << 10),
> +	DVB_FE_FEC_AUTO = (1 << 31)
> +};
> +
> +/*! describes the available modulation types. */
> +enum dvb_fe_modulation {
> +	DVB_FE_MOD_QPSK		= (1 << 0),
> +	DVB_FE_MOD_QAM_16	= (1 << 1),
> +	DVB_FE_MOD_QAM_32	= (1 << 2),
> +	DVB_FE_MOD_QAM_64	= (1 << 3),
> +	DVB_FE_MOD_QAM_128	= (1 << 4),
> +	DVB_FE_MOD_QAM_256	= (1 << 5),
> +	DVB_FE_MOD_QAM_AUTO	= (1 << 6),
> +	DVB_FE_MOD_2_VSB	= (1 << 7),
> +	DVB_FE_MOD_4_VSB	= (1 << 8),
> +	DVB_FE_MOD_8_VSB	= (1 << 9),
> +	DVB_FE_MOD_16_VSB	= (1 << 10),
> +	DVB_FE_MOD_8_PSK	= (1 << 11),
> +	DVB_FE_MOD_BPSK		= (1 << 12),
> +	DVB_FE_MOD_MOD_UNKNOWN	= (1 << 31)
> +};
> +
> +/*! describes common supported frontend capabilities. */
> +enum dvb_fe_common_cap {
> +	DVB_FE_CAN_INVERSION_AUTO   = (1 << 0), /*!< fixme */
> +	DVB_FE_CAN_RECOVER          = (1 << 1), /*!< frontend can recover from a cable unplug automatically */
> +	DVB_FE_CAN_MUTE_TS          = (1 << 2), /*!< frontend can stop spurious TS data output */
> +	DVB_FE_SUP_HIGH_LNB_VOLTAGE = (1 << 31), /*!< fixme, frontend can deliver higher lnb voltages */
> +};
> +
> +/*! describes other available, frontend type dependent capabilities. */
> +enum dvb_fe_other_cap {
> +	DVB_FE_CAN_TRANSMISSION_MODE_AUTO = (1 << 0), /*!< fixme (DVB-T specific) */
> +	DVB_FE_CAN_BANDWIDTH_AUTO         = (1 << 1), /*!< fixme (DVB-T specific) */
> +	DVB_FE_CAN_GUARD_INTERVAL_AUTO    = (1 << 2), /*!< fixme (DVB-T specific) */
> +	DVB_FE_CAN_HIERARCHY_AUTO         = (1 << 31), /*!< fixme (DVB-T specific) */
> +};
> +
> +/**
> + *  this struct will be filled by the FE_GET_EXTENDED_INFO ioctl.
> + *  it is a extension to the normal frontend capabilities and provided
> + *  if the dvb_fe_info.caps is having the FE_HAS_EXTENDED_CAN_VALUES bit set.
> + */
> +struct dvb_fe_caps_extended {
> +	enum dvb_fe_code_rate  caps_fec;        /*!< supported fecs */
> +	enum dvb_fe_modulation caps_modulation; /*!< supported modulations */
> +	enum dvb_fe_common_cap caps_common;     /*!< supported common capabilities */
> +	enum dvb_fe_other_cap  caps_other;      /*!< supported other capabilities*/
> +};
>  
>  /**
>   *  Check out the DiSEqC bus spec available on http://www.eutelsat.org/ for
> @@ -126,7 +194,8 @@
>  	FE_HAS_SYNC	= 0x08,   /*  found sync bytes  */
>  	FE_HAS_LOCK	= 0x10,   /*  everything's working... */
>  	FE_TIMEDOUT	= 0x20,   /*  no lock within the last ~2 seconds */
> -	FE_REINIT	= 0x40    /*  frontend was reinitialized,  */
> +	FE_REINIT	= 0x40,   /*  frontend was reinitialized,  */
> +	FE_EXTENDED_TP  = 0x80    /*  providing new informations */
>  } fe_status_t;			  /*  application is recommended to reset */
>  				  /*  DiSEqC, tone and parameters */
>  
> @@ -163,6 +232,12 @@
>  	VSB_16
>  } fe_modulation_t;
>  
> +typedef enum fe_rolloff_factor {
> +	ROLLOFF_ALPHA_0_35,
> +	ROLLOFF_ALPHA_0_25,
> +	ROLLOFF_ALPHA_0_20
> +} fe_rolloff_factor_t;
> +
>   

According to 302 307, we will need to identify between TSI (Transport 
Stream Input) /GSI (Generic Stream Input)
so we need some more information like this ..

bb_params {
    // TS/GS (2 bits)   (TS / GS (packetized / continuous) )
    // Null packet deletion (active/not active)
    // Transmission Rollof Factor (Alpha) (2 bits)

    // User Packet Length (2 bytes) range = 0 - 65535
    // Data Field Length (2 bytes) range = 0 - 58112
    // Sync Byte (1 byte) MPEG TS = 0x47/Generic packetized stream = 
0x00/unknown for generic continuous streams
    // Sync Distance (2 bytes) distance from the beginning of the DATA 
FIELD and the first UP (User Packet)
}


If we use the packet/sync definitions separately, we can reuse them for 
other protocols , for eg: DSS


Comments .. ?


Manu





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