[PATCH] dvb: b2c2/flexcop driver refactoring part 2: add modular Flexcop driver

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.

How to do something in here?

============================

make -f Makefile.t

make -C ../build-2.6

./in.sh  # load the drivers

./rm.sh  # unload the drivers

Please read this file, if you want to contribute.

This document hopefully describes things about the flexcop and its

device-offsprings. Goal is to write a easy-to-write and easy-to-read set of

drivers based on the skystar2.c and other information.

This directory is temporary. It is used for rewriting the skystar2.c and to

create shared code, which then can be used by the usb box as well.

Remark: flexcop-pci.c was a copy of skystar2.c, but every line has been

touched and rewritten.

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

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)

5c) feeding of ISOC data to the software demux (format of the isochronous data

and speed optimization, no real error)

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                 |

* - 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)

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)

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

Restrictions:

============

We need to create a bus-specific-struct and a flexcop-struct.

bus-specific-struct:

struct flexcop_pci

...

struct flexcop_usb

...

struct flexcop_device {

	void *bus_specific; /* container for bus-specific struct */

...

}

PCI i2c can read/write max 4 bytes at a time, USB can more

Functions

=========

Syntax

------

- Flexcop functions will be called "flexcop(_[a-z0-9]+)+" and exported as such

  if needed.

- Flexcop-device functions will be called "flexcop_device(_[a-z0-9]+)+" and

  exported as such if needed.

- Both will be compiled to b2c2-flexcop.ko and their source can be found in the

  flexcop*.[hc]

Callbacks and exports

---------------------

Bus-specific functions will be given as callbacks (function pointers) to the

flexcop-module. (within the flexcop_device-struct)

Initialization process

======================

b2c2-flexcop.ko is loaded

b2c2-flexcop-<bus>.ko is loaded

suppose a device is found:

malloc flexcop and the bus-specific variables (via flexcop_device_malloc)

fill the bus-specific variable

fill the flexcop variable (especially the bus-specific callbacks)

bus-specific initialization

	- ...

do the common initialization (via flexcop_device_initialize)

	- reset the card

	- determine flexcop type (II, IIB, III)

	- hw_filters (bus dependent)

	- 0x204

	- set sram size

	- create the dvb-stuff

	- create i2c stuff

	- frontend-initialization

done

bus specific:

	- media_destination (this and the following 3 are bus specific)

	- cai_dest

	- cao_dest

	- net_destination

Bugs fixed while rewriting the driver

=====================================

- EEPROM access (to read the MAC address) was fixed to death some time last

  year. (fixed here and in skystar2.c) (Bjarne, this was the piece of code

  (fix-chipaddr) we were wondering about)

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).

comments, critics and ideas to linux-dvb@linuxtv.org or patrick.boettcher@desy.de

source "drivers/media/dvb/cinergyT2/Kconfig"

comment "Supported FlexCopII (B2C2) Adapters"

	depends on DVB_CORE && PCI

	depends on DVB_CORE && (PCI || USB)

source "drivers/media/dvb/b2c2/Kconfig"

comment "Supported BT878 Adapters"

config DVB_B2C2_FLEXCOP

	tristate "Technisat/B2C2 FlexCopII(b) and FlexCopIII adapters"

	depends on DVB_CORE

	select DVB_STV0299

	select DVB_MT352

	select DVB_MT312

	select DVB_NXT2002

	select DVB_STV0297

	help

	  Support for the digital TV receiver chip made by B2C2 Inc. included in

	  Technisats PCI cards and USB boxes.

	  Say Y if you own such a device and want to use it.

config DVB_B2C2_FLEXCOP_PCI

	tristate "Technisat/B2C2 Air/Sky/Cable2PC PCI"

	depends on DVB_B2C2_FLEXCOP && PCI

	help

	  Support for the Air/Sky/CableStar2 PCI card (DVB/ATSC) by Technisat/B2C2.

	  Say Y if you own such a device and want to use it.

config DVB_B2C2_FLEXCOP_USB

	tristate "Technisat/B2C2 Air/Sky/Cable2PC USB"

	depends on DVB_B2C2_FLEXCOP && USB

	help

	  Support for the Air/Sky/Cable2PC USB1.1 box (DVB/ATSC) by Technisat/B2C2,

	  Say Y if you own such a device and want to use it.

config DVB_B2C2_FLEXCOP_DEBUG

	bool "Enable debug for the B2C2 FlexCop drivers"

	depends on DVB_B2C2_FLEXCOP

	help

	  Say Y if you want to enable the module option to control debug messages

	  of all B2C2 FlexCop drivers.

config DVB_B2C2_SKYSTAR

	tristate "B2C2/Technisat Air/Sky/CableStar 2 PCI"

	depends on DVB_CORE && PCI

b2c2-flexcop-objs = flexcop.o flexcop-fe-tuner.o flexcop-i2c.o \

	flexcop-sram.o flexcop-eeprom.o flexcop-misc.o flexcop-hw-filter.o \

	flexcop-dma.o

obj-$(CONFIG_DVB_B2C2_FLEXCOP) += b2c2-flexcop.o

b2c2-flexcop-pci-objs = flexcop-pci.o

obj-$(CONFIG_DVB_B2C2_FLEXCOP_PCI) += b2c2-flexcop-pci.o

b2c2-flexcop-usb-objs = flexcop-usb.o

obj-$(CONFIG_DVB_B2C2_FLEXCOP_USB) += b2c2-flexcop-usb.o

obj-$(CONFIG_DVB_B2C2_SKYSTAR) += skystar2.o

EXTRA_CFLAGS = -Idrivers/media/dvb/dvb-core/ -Idrivers/media/dvb/frontends/

/*

 * This file is part of linux driver the digital TV devices equipped with B2C2 FlexcopII(b)/III

 *

 * flexcop-common.h - common header file for device-specific source files also.

 *

 * see flexcop.c for copyright information.

 */

#ifndef __FLEXCOP_COMMON_H__

#define __FLEXCOP_COMMON_H__

#include <linux/config.h>

#include <linux/pci.h>

#include "flexcop-reg.h"

#include "dmxdev.h"

#include "dvb_demux.h"

#include "dvb_filter.h"

#include "dvb_net.h"

#include "dvb_frontend.h"

#define FC_MAX_FEED 256

#ifndef FC_LOG_PREFIX

#warning please define a log prefix for your file, using a default one

#define FC_LOG_PREFIX "b2c2-undef"

#endif

/* Steal from usb.h */

#undef err

#define err(format,  arg...) printk(KERN_ERR     FC_LOG_PREFIX ": " format "\n" , ## arg)

#undef info

#define info(format, arg...) printk(KERN_INFO    FC_LOG_PREFIX ": " format "\n" , ## arg)

#undef warn

#define warn(format, arg...) printk(KERN_WARNING FC_LOG_PREFIX ": " format "\n" , ## arg)

struct flexcop_dma {

	struct pci_dev *pdev;

	u8 *cpu_addr0;

	dma_addr_t dma_addr0;

	u8 *cpu_addr1;

	dma_addr_t dma_addr1;

	u32 size; /* size of each address in bytes */

};

/* Control structure for data definitions that are common to

 * the B2C2-based PCI and USB devices.

 */

struct flexcop_device {

	/* general */

	struct device *dev; /* for firmware_class */

#define FC_STATE_DVB_INIT 0x01

#define FC_STATE_I2C_INIT 0x02

#define FC_STATE_FE_INIT  0x04

	int init_state;

	/* device information */

	u8 mac_address[6];

	int has_32_hw_pid_filter;

	flexcop_revision_t rev;

	flexcop_device_type_t dev_type;

	flexcop_bus_t bus_type;

	/* dvb stuff */

	struct dvb_adapter dvb_adapter;

	struct dvb_frontend *fe;

	struct dvb_net dvbnet;

	struct dvb_demux demux;

	struct dmxdev dmxdev;

	struct dmx_frontend hw_frontend;

	struct dmx_frontend mem_frontend;

	int (*fe_sleep) (struct dvb_frontend *);

	struct i2c_adapter i2c_adap;

	struct semaphore i2c_sem;

	/* options and status */

	int feedcount;

	int pid_filtering;

	/* bus specific callbacks */

	flexcop_ibi_value (*read_ibi_reg)  (struct flexcop_device *, flexcop_ibi_register);

	int               (*write_ibi_reg) (struct flexcop_device *, flexcop_ibi_register, flexcop_ibi_value);

	int (*i2c_request) (struct flexcop_device*, flexcop_access_op_t, flexcop_i2c_port_t, u8 chipaddr, u8 addr, u8 *buf, u16 len);

	int (*stream_control) (struct flexcop_device*, int);

	int (*get_mac_addr) (struct flexcop_device *fc, int extended);

	void *bus_specific;

};

/* exported prototypes */

/* from flexcop.c */

void flexcop_pass_dmx_data(struct flexcop_device *fc, u8 *buf, u32 len);

void flexcop_pass_dmx_packets(struct flexcop_device *fc, u8 *buf, u32 no);

struct flexcop_device *flexcop_device_kmalloc(size_t bus_specific_len);

void flexcop_device_kfree(struct flexcop_device*);

int  flexcop_device_initialize(struct flexcop_device*);

void flexcop_device_exit(struct flexcop_device *fc);

/* from flexcop-dma.c */

int flexcop_dma_allocate(struct pci_dev *pdev, struct flexcop_dma *dma, u32 size);

void flexcop_dma_free(struct flexcop_dma *dma);

int flexcop_dma_control_timer_irq(struct flexcop_device *fc, flexcop_dma_index_t no, int onoff);

int flexcop_dma_control_size_irq(struct flexcop_device *fc, flexcop_dma_index_t no, int onoff);

int flexcop_dma_control_packet_irq(struct flexcop_device *fc, flexcop_dma_index_t no, int onoff);

int flexcop_dma_config(struct flexcop_device *fc, struct flexcop_dma *dma, flexcop_dma_index_t dma_idx,flexcop_dma_addr_index_t index);

int flexcop_dma_config_timer(struct flexcop_device *fc, flexcop_dma_index_t dma_idx, u8 cycles);

int flexcop_dma_config_packet_count(struct flexcop_device *fc, flexcop_dma_index_t dma_idx, u8 packets);

/* from flexcop-eeprom.c */

/* the PCI part uses this call to get the MAC address, the USB part has its own */

int flexcop_eeprom_check_mac_addr(struct flexcop_device *fc, int extended);

/* from flexcop-i2c.c */

/* the PCI part uses this a i2c_request callback, whereas the usb part has its own

 * one. We have it in flexcop-i2c.c, because it is going via the actual

 * I2C-channel of the flexcop.

 */

int flexcop_i2c_request(struct flexcop_device*, flexcop_access_op_t,

		        flexcop_i2c_port_t, u8 chipaddr, u8 addr, u8 *buf, u16 len);

/* from flexcop-sram.c */

int flexcop_sram_set_dest(struct flexcop_device *fc, flexcop_sram_dest_t dest, flexcop_sram_dest_target_t target);

void flexcop_wan_set_speed(struct flexcop_device *fc, flexcop_wan_speed_t s);

void flexcop_sram_ctrl(struct flexcop_device *fc, int usb_wan, int sramdma, int maximumfill);

/* global prototypes for the flexcop-chip */

/* from flexcop-fe-tuner.c */

int flexcop_frontend_init(struct flexcop_device *card);

void flexcop_frontend_exit(struct flexcop_device *fc);

/* from flexcop-i2c.c */

int flexcop_i2c_init(struct flexcop_device *fc);

void flexcop_i2c_exit(struct flexcop_device *fc);

/* from flexcop-sram.c */

int flexcop_sram_init(struct flexcop_device *fc);

/* from flexcop-misc.c */

void flexcop_determine_revision(struct flexcop_device *fc);

void flexcop_device_name(struct flexcop_device *fc,const char *prefix,const char *suffix);

/* from flexcop-hw-filter.c */

int flexcop_pid_feed_control(struct flexcop_device *fc, struct dvb_demux_feed *dvbdmxfeed, int onoff);

void flexcop_hw_filter_init(struct flexcop_device *fc);

void flexcop_smc_ctrl(struct flexcop_device *fc, int onoff);

void flexcop_set_mac_filter(struct flexcop_device *fc, u8 mac[6]);

void flexcop_mac_filter_ctrl(struct flexcop_device *fc, int onoff);

#endif