diff options
Diffstat (limited to 'drivers/media/dvb-core/demux.h')
-rw-r--r-- | drivers/media/dvb-core/demux.h | 71 |
1 files changed, 4 insertions, 67 deletions
diff --git a/drivers/media/dvb-core/demux.h b/drivers/media/dvb-core/demux.h index 6d3b95b8939d..e8f04f8872f8 100644 --- a/drivers/media/dvb-core/demux.h +++ b/drivers/media/dvb-core/demux.h @@ -1,6 +1,10 @@ /* * demux.h * + * The Kernel Digital TV Demux kABI defines a driver-internal interface for + * registering low-level, hardware specific driver to a hardware independent + * demux layer. + * * Copyright (c) 2002 Convergence GmbH * * based on code: @@ -32,49 +36,6 @@ #include <linux/time.h> #include <linux/dvb/dmx.h> -/** - * DOC: Digital TV Demux - * - * The Kernel Digital TV Demux kABI defines a driver-internal interface for - * registering low-level, hardware specific driver to a hardware independent - * demux layer. It is only of interest for Digital TV device driver writers. - * The header file for this kABI is named demux.h and located in - * drivers/media/dvb-core. - * - * The demux kABI should be implemented for each demux in the system. It is - * used to select the TS source of a demux and to manage the demux resources. - * When the demux client allocates a resource via the demux kABI, it receives - * a pointer to the kABI of that resource. - * - * Each demux receives its TS input from a DVB front-end or from memory, as - * set via this demux kABI. In a system with more than one front-end, the kABI - * can be used to select one of the DVB front-ends as a TS source for a demux, - * unless this is fixed in the HW platform. - * - * The demux kABI only controls front-ends regarding to their connections with - * demuxes; the kABI used to set the other front-end parameters, such as - * tuning, are devined via the Digital TV Frontend kABI. - * - * The functions that implement the abstract interface demux should be defined - * static or module private and registered to the Demux core for external - * access. It is not necessary to implement every function in the struct - * &dmx_demux. For example, a demux interface might support Section filtering, - * but not PES filtering. The kABI client is expected to check the value of any - * function pointer before calling the function: the value of NULL means - * that the function is not available. - * - * Whenever the functions of the demux API modify shared data, the - * possibilities of lost update and race condition problems should be - * addressed, e.g. by protecting parts of code with mutexes. - * - * Note that functions called from a bottom half context must not sleep. - * Even a simple memory allocation without using %GFP_ATOMIC can result in a - * kernel thread being put to sleep if swapping is needed. For example, the - * Linux Kernel calls the functions of a network device interface from a - * bottom half context. Thus, if a demux kABI function is called from network - * device code, the function must not sleep. - */ - /* * Common definitions */ @@ -231,30 +192,6 @@ struct dmx_section_feed { }; /** - * DOC: Demux Callback - * - * This kernel-space API comprises the callback functions that deliver filtered - * data to the demux client. Unlike the other DVB kABIs, these functions are - * provided by the client and called from the demux code. - * - * The function pointers of this abstract interface are not packed into a - * structure as in the other demux APIs, because the callback functions are - * registered and used independent of each other. As an example, it is possible - * for the API client to provide several callback functions for receiving TS - * packets and no callbacks for PES packets or sections. - * - * The functions that implement the callback API need not be re-entrant: when - * a demux driver calls one of these functions, the driver is not allowed to - * call the function again before the original call returns. If a callback is - * triggered by a hardware interrupt, it is recommended to use the Linux - * bottom half mechanism or start a tasklet instead of making the callback - * function call directly from a hardware interrupt. - * - * This mechanism is implemented by dmx_ts_cb() and dmx_section_cb() - * callbacks. - */ - -/** * typedef dmx_ts_cb - DVB demux TS filter callback function prototype * * @buffer1: Pointer to the start of the filtered TS packets. |