| 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. |