+++ /dev/null
-This README escorted the skystar2-driver rewriting procedure. It describes the
-state of the new flexcop-driver set and some internals are written down here
-too.
-
-This document hopefully describes things about the flexcop and its
-device-offsprings. Goal was to write an easy-to-write and easy-to-read set of
-drivers based on the skystar2.c and other information.
-
-Remark: flexcop-pci.c was a copy of skystar2.c, but every line has been
-touched and rewritten.
-
-History & News
-==============
- 2005-04-01 - correct USB ISOC transfers (thanks to Vadim Catana)
-
-
-
-
-General coding processing
-=========================
-
-We should proceed as follows (as long as no one complains):
-
-0) Think before start writing code!
-
-1) rewriting the skystar2.c with the help of the flexcop register descriptions
-and splitting up the files to a pci-bus-part and a flexcop-part.
-The new driver will be called b2c2-flexcop-pci.ko/b2c2-flexcop-usb.ko for the
-device-specific part and b2c2-flexcop.ko for the common flexcop-functions.
-
-2) Search for errors in the leftover of flexcop-pci.c (compare with pluto2.c
-and other pci drivers)
-
-3) make some beautification (see 'Improvements when rewriting (refactoring) is
-done')
-
-4) Testing the new driver and maybe substitute the skystar2.c with it, to reach
-a wider tester audience.
-
-5) creating an usb-bus-part using the already written flexcop code for the pci
-card.
-
-Idea: create a kernel-object for the flexcop and export all important
-functions. This option saves kernel-memory, but maybe a lot of functions have
-to be exported to kernel namespace.
-
-
-Current situation
-=================
-
-0) Done :)
-1) Done (some minor issues left)
-2) Done
-3) Not ready yet, more information is necessary
-4) next to be done (see the table below)
-5) USB driver is working (yes, there are some minor issues)
-
-What seems to be ready?
------------------------
-
-1) Rewriting
-1a) i2c is cut off from the flexcop-pci.c and seems to work
-1b) moved tuner and demod stuff from flexcop-pci.c to flexcop-tuner-fe.c
-1c) moved lnb and diseqc stuff from flexcop-pci.c to flexcop-tuner-fe.c
-1e) eeprom (reading MAC address)
-1d) sram (no dynamic sll size detection (commented out) (using default as JJ told me))
-1f) misc. register accesses for reading parameters (e.g. resetting, revision)
-1g) pid/mac filter (flexcop-hw-filter.c)
-1i) dvb-stuff initialization in flexcop.c (done)
-1h) dma stuff (now just using the size-irq, instead of all-together, to be done)
-1j) remove flexcop initialization from flexcop-pci.c completely (done)
-1l) use a well working dma IRQ method (done, see 'Known bugs and problems and TODO')
-1k) cleanup flexcop-files (remove unused EXPORT_SYMBOLs, make static from
-non-static where possible, moved code to proper places)
-
-2) Search for errors in the leftover of flexcop-pci.c (partially done)
-5a) add MAC address reading
-5c) feeding of ISOC data to the software demux (format of the isochronous data
-and speed optimization, no real error) (thanks to Vadim Catana)
-
-What to do in the near future?
---------------------------------------
-(no special order here)
-
-5) USB driver
-5b) optimize isoc-transfer (submitting/killing isoc URBs when transfer is starting)
-
-Testing changes
----------------
-
-O = item is working
-P = item is partially working
-X = item is not working
-N = item does not apply here
-<empty field> = item need to be examined
-
- | PCI | USB
-item | mt352 | nxt2002 | stv0299 | mt312 | mt352 | nxt2002 | stv0299 | mt312
--------+-------+---------+---------+-------+-------+---------+---------+-------
-1a) | O | | | | N | N | N | N
-1b) | O | | | | | | O |
-1c) | N | N | | | N | N | O |
-1d) | O | O
-1e) | O | O
-1f) | P
-1g) | O
-1h) | P |
-1i) | O | N
-1j) | O | N
-1l) | O | N
-2) | O | N
-5a) | N | O
-5b)* | N |
-5c) | N | O
-
-* - not done yet
-
-Known bugs and problems and TODO
---------------------------------
-
-1g/h/l) when pid filtering is enabled on the pci card
-
-DMA usage currently:
- The DMA is splitted in 2 equal-sized subbuffers. The Flexcop writes to first
- address and triggers an IRQ when it's full and starts writing to the second
- address. When the second address is full, the IRQ is triggered again, and
- the flexcop writes to first address again, and so on.
- The buffersize of each address is currently 640*188 bytes.
-
- Problem is, when using hw-pid-filtering and doing some low-bandwidth
- operation (like scanning) the buffers won't be filled enough to trigger
- the IRQ. That's why:
-
- When PID filtering is activated, the timer IRQ is used. Every 1.97 ms the IRQ
- is triggered. Is the current write address of DMA1 different to the one
- during the last IRQ, then the data is passed to the demuxer.
-
- There is an additional DMA-IRQ-method: packet count IRQ. This isn't
- implemented correctly yet.
-
- The solution is to disable HW PID filtering, but I don't know how the DVB
- API software demux behaves on slow systems with 45MBit/s TS.
-
-Solved bugs :)
---------------
-1g) pid-filtering (somehow pid index 4 and 5 (EMM_PID and ECM_PID) aren't
-working)
-SOLUTION: also index 0 was affected, because net_translation is done for
-these indexes by default
-
-5b) isochronous transfer does only work in the first attempt (for the Sky2PC
-USB, Air2PC is working) SOLUTION: the flexcop was going asleep and never really
-woke up again (don't know if this need fixes, see
-flexcop-fe-tuner.c:flexcop_sleep)
-
-NEWS: when the driver is loaded and unloaded and loaded again (w/o doing
-anything in the while the driver is loaded the first time), no transfers take
-place anymore.
-
-Improvements when rewriting (refactoring) is done
-=================================================
-
-- split sleeping of the flexcop (misc_204.ACPI3_sig = 1;) from lnb_control
- (enable sleeping for other demods than dvb-s)
-- add support for CableStar (stv0297 Microtune 203x/ALPS) (almost done, incompatibilities with the Nexus-CA)
-
-Debugging
----------
-- add verbose debugging to skystar2.c (dump the reg_dw_data) and compare it
- with this flexcop, this is important, because i2c is now using the
- flexcop_ibi_value union from flexcop-reg.h (do you have a better idea for
- that, please tell us so).
-
-Everything which is identical in the following table, can be put into a common
-flexcop-module.
-
- PCI USB
--------------------------------------------------------------------------------
-Different:
-Register access: accessing IO memory USB control message
-I2C bus: I2C bus of the FC USB control message
-Data transfer: DMA isochronous transfer
-EEPROM transfer: through i2c bus not clear yet
-
-Identical:
-Streaming: accessing registers
-PID Filtering: accessing registers
-Sram destinations: accessing registers
-Tuner/Demod: I2C bus
-DVB-stuff: can be written for common use
-
-Acknowledgements (just for the rewriting part)
-================
-
-Bjarne Steinsbo thought a lot in the first place of the pci part for this code
-sharing idea.
-
-Andreas Oberritter for providing a recent PCI initialization template
-(pluto2.c).
-
-Boleslaw Ciesielski for pointing out a problem with firmware loader.
-
-Vadim Catana for correcting the USB transfer.
-
-comments, critics and ideas to linux-dvb@linuxtv.org.
Code Review / linux-2.6.git / commitdiff