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Linus Torvalds1da177e2005-04-16 15:20:36 -07001 README FOR LINUX SONY CDU-535/531 DRIVER
2 ========================================
3
4This is the Sony CDU-535 (and 531) driver version 0.7 for Linux.
5I do not think I have the documentation to add features like DMA support
6so if anyone else wants to pursue it or help me with it, please do.
7(I need to see what was done for the CDU-31A driver -- perhaps I can
8steal some of that code.)
9
10This is a Linux device driver for the Sony CDU-535 CDROM drive. This is
11one of the older Sony drives with its own interface card (Sony bus).
12The DOS driver for this drive is named SONY_CDU.SYS - when you boot DOS
13your drive should be identified as a SONY CDU-535. The driver works
14with a CDU-531 also. One user reported that the driver worked on drives
15OEM'ed by Procomm, drive and interface board were labelled Procomm.
16
17The Linux driver is based on Corey Minyard's sonycd 0.3 driver for
18the CDU-31A. Ron Jeppesen just changed the commands that were sent
19to the drive to correspond to the CDU-535 commands and registers.
20There were enough changes to let bugs creep in but it seems to be stable.
21Ron was able to tar an entire CDROM (should read all blocks) and built
22ghostview and xfig off Walnut Creek's X11R5/GNU CDROM. xcdplayer and
23workman work with the driver. Others have used the driver without
24problems except those dealing with wait loops (fixed in third release).
25Like Minyard's original driver this one uses a polled interface (this
26is also the default setup for the DOS driver). It has not been tried
27with interrupts or DMA enabled on the board.
28
29REQUIREMENTS
30============
31
32 - Sony CDU-535 drive, preferably without interrupts and DMA
33 enabled on the card.
34
35 - Drive must be set up as unit 1. Only the first unit will be
36 recognized
37
38 - You must enter your interface address into
39 /usr/src/linux/drivers/cdrom/sonycd535.h and build the
40 appropriate kernel or use the "kernel command line" parameter
41 sonycd535=0x320
42 with the correct interface address.
43
44NOTES:
45======
46
471) The drive MUST be turned on when booting or it will not be recognized!
48 (but see comments on modularized version below)
49
502) when the cdrom device is opened the eject button is disabled to keep the
51 user from ejecting a mounted disk and replacing it with another.
52 Unfortunately xcdplayer and workman also open the cdrom device so you
53 have to use the eject button in the software. Keep this in mind if your
54 cdrom player refuses to give up its disk -- exit workman or xcdplayer, or
55 umount the drive if it has been mounted.
56
57THANKS
58======
59
60Many thanks to Ron Jeppesen (ronj.an@site007.saic.com) for getting
61this project off the ground. He wrote the initial release
62and the first two patches to this driver (0.1, 0.2, and 0.3).
63Thanks also to Eberhard Moenkeberg (emoenke@gwdg.de) for prodding
64me to place this code into the mainstream Linux source tree
65(as of Linux version 1.1.91), as well as some patches to make
66it a better device citizen. Further thanks to Joel Katz
67<joelkatz@webchat.org> for his MODULE patches (see details below),
68Porfiri Claudio <C.Porfiri@nisms.tei.ericsson.se> for patches
69to make the driver work with the older CDU-510/515 series, and
70Heiko Eissfeldt <heiko@colossus.escape.de> for pointing out that
71the verify_area() checks were ignoring the results of said checks.
72
73(Acknowledgments from Ron Jeppesen in the 0.3 release:)
74Thanks to Corey Minyard who wrote the original CDU-31A driver on which
75this driver is based. Thanks to Ken Pizzini and Bob Blair who provided
76patches and feedback on the first release of this driver.
77
78Ken Pizzini
79ken@halcyon.com
80
81------------------------------------------------------------------------------
82(The following is from Joel Katz <joelkatz@webchat.org>.)
83
84 To build a version of sony535.o that can be installed as a module,
85use the following command:
86
87gcc -c -D__KERNEL__ -DMODULE -O2 sonycd535.c -o sonycd535.o
88
89 To install the module, simply type:
90
91insmod sony535.o
92 or
93insmod sony535.o sonycd535=<address>
94
95 And to remove it:
96
97rmmod sony535
98
99 The code checks to see if MODULE is defined and behaves as it used
100to if MODULE is not defined. That means your patched file should behave
101exactly as it used to if compiled into the kernel.
102
103 I have an external drive, and I usually leave it powered off. I used
104to have to reboot if I needed to use the CDROM drive. Now I don't.
105
106 Even if you have an internal drive, why waste the 96K of memory
107(unswappable) that the driver uses if you use your CD-ROM drive infrequently?
108
109 This driver will not install (whether compiled in or loaded as a
110module) if the CDROM drive is not available during its initialization. This
111means that you can have the driver compiled into the kernel and still load
112the module later (assuming the driver doesn't install itself during
113power-on). This only wastes 12K when you boot with the CDROM drive off.
114
115 This is what I usually do; I leave the driver compiled into the
116kernel, but load it as a module if I powered the system up with the drive
117off and then later decided to use the CDROM drive.
118
119 Since the driver only uses a single page to point to the chunks,
120attempting to set the buffer cache to more than 2 Megabytes would be very
121bad; don't do that.