mirror of
https://github.com/torvalds/linux.git
synced 2024-11-28 07:01:32 +00:00
674434c691
Clean up whitespaces at v4l/dvb files Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
206 lines
7.8 KiB
Plaintext
206 lines
7.8 KiB
Plaintext
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.
|