3 Mike Isely <isely@pobox.com>
9 This driver is intended for the "Hauppauge WinTV PVR USB 2.0", which
10 is a USB 2.0 hosted TV Tuner. This driver is a work in progress.
11 Its history started with the reverse-engineering effort by Björn
12 Danielsson <pvrusb2@dax.nu> whose web page can be found here:
14 http://pvrusb2.dax.nu/
16 From there Aurelien Alleaume <slts@free.fr> began an effort to
17 create a video4linux compatible driver. I began with Aurelien's
18 last known snapshot and evolved the driver to the state it is in
21 More information on this driver can be found at:
23 http://www.isely.net/pvrusb2.html
26 This driver has a strong separation of layers. They are very
29 1a. Low level wire-protocol implementation with the device.
31 1b. I2C adaptor implementation and corresponding I2C client drivers
32 implemented elsewhere in V4L.
34 1c. High level hardware driver implementation which coordinates all
35 activities that ensure correct operation of the device.
37 2. A "context" layer which manages instancing of driver, setup,
38 tear-down, arbitration, and interaction with high level
39 interfaces appropriately as devices are hotplugged in the
42 3. High level interfaces which glue the driver to various published
43 Linux APIs (V4L, sysfs, maybe DVB in the future).
45 The most important shearing layer is between the top 2 layers. A
46 lot of work went into the driver to ensure that any kind of
47 conceivable API can be laid on top of the core driver. (Yes, the
48 driver internally leverages V4L to do its work but that really has
49 nothing to do with the API published by the driver to the outside
50 world.) The architecture allows for different APIs to
51 simultaneously access the driver. I have a strong sense of fairness
52 about APIs and also feel that it is a good design principle to keep
53 implementation and interface isolated from each other. Thus while
54 right now the V4L high level interface is the most complete, the
55 sysfs high level interface will work equally well for similar
56 functions, and there's no reason I see right now why it shouldn't be
57 possible to produce a DVB high level interface that can sit right
60 NOTE: Complete documentation on the pvrusb2 driver is contained in
61 the html files within the doc directory; these are exactly the same
62 as what is on the web site at the time. Browse those files
63 (especially the FAQ) before asking questions.
68 To build these modules essentially amounts to just running "Make",
69 but you need the kernel source tree nearby and you will likely also
70 want to set a few controlling environment variables first in order
71 to link things up with that source tree. Please see the Makefile
72 here for comments that explain how to do that.
75 Source file list / functional overview:
77 (Note: The term "module" used below generally refers to loosely
78 defined functional units within the pvrusb2 driver and bears no
79 relation to the Linux kernel's concept of a loadable module.)
81 pvrusb2-audio.[ch] - This is glue logic that resides between this
82 driver and the msp3400.ko I2C client driver (which is found
85 pvrusb2-context.[ch] - This module implements the context for an
86 instance of the driver. Everything else eventually ties back to
87 or is otherwise instanced within the data structures implemented
88 here. Hotplugging is ultimately coordinated here. All high level
89 interfaces tie into the driver through this module. This module
90 helps arbitrate each interface's access to the actual driver core,
91 and is designed to allow concurrent access through multiple
92 instances of multiple interfaces (thus you can for example change
93 the tuner's frequency through sysfs while simultaneously streaming
94 video through V4L out to an instance of mplayer).
96 pvrusb2-debug.h - This header defines a printk() wrapper and a mask
97 of debugging bit definitions for the various kinds of debug
98 messages that can be enabled within the driver.
100 pvrusb2-debugifc.[ch] - This module implements a crude command line
101 oriented debug interface into the driver. Aside from being part
102 of the process for implementing manual firmware extraction (see
103 the pvrusb2 web site mentioned earlier), probably I'm the only one
104 who has ever used this. It is mainly a debugging aid.
106 pvrusb2-eeprom.[ch] - This is glue logic that resides between this
107 driver the tveeprom.ko module, which is itself implemented
110 pvrusb2-encoder.[ch] - This module implements all protocol needed to
111 interact with the Conexant mpeg2 encoder chip within the pvrusb2
112 device. It is a crude echo of corresponding logic in ivtv,
113 however the design goals (strict isolation) and physical layer
114 (proxy through USB instead of PCI) are enough different that this
115 implementation had to be completely different.
117 pvrusb2-hdw-internal.h - This header defines the core data structure
118 in the driver used to track ALL internal state related to control
119 of the hardware. Nobody outside of the core hardware-handling
120 modules should have any business using this header. All external
121 access to the driver should be through one of the high level
122 interfaces (e.g. V4L, sysfs, etc), and in fact even those high
123 level interfaces are restricted to the API defined in
124 pvrusb2-hdw.h and NOT this header.
126 pvrusb2-hdw.h - This header defines the full internal API for
127 controlling the hardware. High level interfaces (e.g. V4L, sysfs)
128 will work through here.
130 pvrusb2-hdw.c - This module implements all the various bits of logic
131 that handle overall control of a specific pvrusb2 device.
132 (Policy, instantiation, and arbitration of pvrusb2 devices fall
133 within the jurisdiction of pvrusb-context not here).
135 pvrusb2-i2c-chips-*.c - These modules implement the glue logic to
136 tie together and configure various I2C modules as they attach to
137 the I2C bus. There are two versions of this file. The "v4l2"
138 version is intended to be used in-tree alongside V4L, where we
139 implement just the logic that makes sense for a pure V4L
140 environment. The "all" version is intended for use outside of
141 V4L, where we might encounter other possibly "challenging" modules
142 from ivtv or older kernel snapshots (or even the support modules
143 in the standalone snapshot).
145 pvrusb2-i2c-cmd-v4l1.[ch] - This module implements generic V4L1
146 compatible commands to the I2C modules. It is here where state
147 changes inside the pvrusb2 driver are translated into V4L1
148 commands that are in turn send to the various I2C modules.
150 pvrusb2-i2c-cmd-v4l2.[ch] - This module implements generic V4L2
151 compatible commands to the I2C modules. It is here where state
152 changes inside the pvrusb2 driver are translated into V4L2
153 commands that are in turn send to the various I2C modules.
155 pvrusb2-i2c-core.[ch] - This module provides an implementation of a
156 kernel-friendly I2C adaptor driver, through which other external
157 I2C client drivers (e.g. msp3400, tuner, lirc) may connect and
158 operate corresponding chips within the the pvrusb2 device. It is
159 through here that other V4L modules can reach into this driver to
160 operate specific pieces (and those modules are in turn driven by
161 glue logic which is coordinated by pvrusb2-hdw, doled out by
162 pvrusb2-context, and then ultimately made available to users
163 through one of the high level interfaces).
165 pvrusb2-io.[ch] - This module implements a very low level ring of
166 transfer buffers, required in order to stream data from the
167 device. This module is *very* low level. It only operates the
168 buffers and makes no attempt to define any policy or mechanism for
169 how such buffers might be used.
171 pvrusb2-ioread.[ch] - This module layers on top of pvrusb2-io.[ch]
172 to provide a streaming API usable by a read() system call style of
173 I/O. Right now this is the only layer on top of pvrusb2-io.[ch],
174 however the underlying architecture here was intended to allow for
175 other styles of I/O to be implemented with additonal modules, like
176 mmap()'ed buffers or something even more exotic.
178 pvrusb2-main.c - This is the top level of the driver. Module level
179 and USB core entry points are here. This is our "main".
181 pvrusb2-sysfs.[ch] - This is the high level interface which ties the
182 pvrusb2 driver into sysfs. Through this interface you can do
183 everything with the driver except actually stream data.
185 pvrusb2-tuner.[ch] - This is glue logic that resides between this
186 driver and the tuner.ko I2C client driver (which is found
189 pvrusb2-util.h - This header defines some common macros used
190 throughout the driver. These macros are not really specific to
191 the driver, but they had to go somewhere.
193 pvrusb2-v4l2.[ch] - This is the high level interface which ties the
194 pvrusb2 driver into video4linux. It is through here that V4L
195 applications can open and operate the driver in the usual V4L
196 ways. Note that **ALL** V4L functionality is published only
197 through here and nowhere else.
199 pvrusb2-video-*.[ch] - This is glue logic that resides between this
200 driver and the saa711x.ko I2C client driver (which is found
201 elsewhere in V4L). Note that saa711x.ko used to be known as
202 saa7115.ko in ivtv. There are two versions of this; one is
203 selected depending on the particular saa711[5x].ko that is found.
205 pvrusb2.h - This header contains compile time tunable parameters
206 (and at the moment the driver has very little that needs to be
projects / linux-2.6 / blob