| CDU31A/CDU33A Driver Info | |
| ------------------------- | |
| Information on the Sony CDU31A/CDU33A CDROM driver for the Linux | |
| kernel. | |
| Corey Minyard (minyard@metronet.com) | |
| Colossians 3:17 | |
| Crude Table of Contents | |
| ----------------------- | |
| Setting Up the Hardware | |
| Configuring the Kernel | |
| Configuring as a Module | |
| Driver Special Features | |
| This device driver handles Sony CDU31A/CDU33A CDROM drives and | |
| provides a complete block-level interface as well as an ioctl() | |
| interface as specified in include/linux/cdrom.h). With this | |
| interface, CDROMs can be accessed, standard audio CDs can be played | |
| back normally, and CD audio information can be read off the drive. | |
| Note that this will only work for CDU31A/CDU33A drives. Some vendors | |
| market their drives as CDU31A compatible. They lie. Their drives are | |
| really CDU31A hardware interface compatible (they can plug into the | |
| same card). They are not software compatible. | |
| Setting Up the Hardware | |
| ----------------------- | |
| The CDU31A driver is unable to safely tell if an interface card is | |
| present that it can use because the interface card does not announce | |
| its presence in any way besides placing 4 I/O locations in memory. It | |
| used to just probe memory and attempt commands, but Linus wisely asked | |
| me to remove that because it could really screw up other hardware in | |
| the system. | |
| Because of this, you must tell the kernel where the drive interface | |
| is, what interrupts are used, and possibly if you are on a PAS-16 | |
| soundcard. | |
| If you have the Sony CDU31A/CDU33A drive interface card, the following | |
| diagram will help you set it up. If you have another card, you are on | |
| your own. You need to make sure that the I/O address and interrupt is | |
| not used by another card in the system. You will need to know the I/O | |
| address and interrupt you have set. Note that use of interrupts is | |
| highly recommended, if possible, it really cuts down on CPU used. | |
| Unfortunately, most soundcards do not support interrupts for their | |
| CDROM interfaces. By default, the Sony interface card comes with | |
| interrupts disabled. | |
| +----------+-----------------+----------------------+ | |
| | JP1 | 34 Pin Conn | | | |
| | JP2 +-----------------+ | | |
| | JP3 | | |
| | JP4 | | |
| | +--+ | |
| | | +-+ | |
| | | | | External | |
| | | | | Connector | |
| | | | | | |
| | | +-+ | |
| | +--+ | |
| | | | |
| | +--------+ | |
| | | | |
| +------------------------------------------+ | |
| JP1 sets the Base Address, using the following settings: | |
| Address Pin 1 Pin 2 | |
| ------- ----- ----- | |
| 0x320 Short Short | |
| 0x330 Short Open | |
| 0x340 Open Short | |
| 0x360 Open Open | |
| JP2 and JP3 configure the DMA channel; they must be set the same. | |
| DMA Pin 1 Pin 2 Pin 3 | |
| --- ----- ----- ----- | |
| 1 On Off On | |
| 2 Off On Off | |
| 3 Off Off On | |
| JP4 Configures the IRQ: | |
| IRQ Pin 1 Pin 2 Pin 3 Pin 4 | |
| --- ----- ----- ----- ----- | |
| 3 Off Off On Off | |
| 4 Off Off* Off On | |
| 5 On Off Off Off | |
| 6 Off On Off Off | |
| The documentation states to set this for interrupt | |
| 4, but I think that is a mistake. | |
| Note that if you have another interface card, you will need to look at | |
| the documentation to find the I/O base address. This is specified to | |
| the SLCD.SYS driver for DOS with the /B: parameter, so you can look at | |
| you DOS driver setup to find the address, if necessary. | |
| Configuring the Kernel | |
| ---------------------- | |
| You must tell the kernel where the drive is at boot time. This can be | |
| done at the Linux boot prompt, by using LILO, or by using Bootlin. | |
| Note that this is no substitute for HOWTOs and LILO documentation, if | |
| you are confused please read those for info on bootline configuration | |
| and LILO. | |
| At the linux boot prompt, press the ALT key and add the following line | |
| after the boot name (you can let the kernel boot, it will tell you the | |
| default boot name while booting): | |
| cdu31a=<base address>,<interrupt>[,PAS] | |
| The base address needs to have "0x" in front of it, since it is in | |
| hex. For instance, to configure a drive at address 320 on interrupt 5, | |
| use the following: | |
| cdu31a=0x320,5 | |
| I use the following boot line: | |
| cdu31a=0x1f88,0,PAS | |
| because I have a PAS-16 which does not support interrupt for the | |
| CDU31A interface. | |
| Adding this as an append line at the beginning of the /etc/lilo.conf | |
| file will set it for lilo configurations. I have the following as the | |
| first line in my lilo.conf file: | |
| append="cdu31a=0x1f88,0" | |
| I'm not sure how to set up Bootlin (I have never used it), if someone | |
| would like to fill in this section please do. | |
| Configuring as a Module | |
| ----------------------- | |
| The driver supports loading as a module. However, you must specify | |
| the boot address and interrupt on the boot line to insmod. You can't | |
| use modprobe to load it, since modprobe doesn't support setting | |
| variables. | |
| Anyway, I use the following line to load my driver as a module | |
| /sbin/insmod /lib/modules/`uname -r`/misc/cdu31a.o cdu31a_port=0x1f88 | |
| You can set the following variables in the driver: | |
| cdu31a_port=<I/O address> - sets the base I/O. If hex, put 0x in | |
| front of it. This must be specified. | |
| cdu31a_irq=<interrupt> - Sets the interrupt number. Leaving this | |
| off will turn interrupts off. | |
| Driver Special Features | |
| ----------------------- | |
| This section describes features beyond the normal audio and CD-ROM | |
| functions of the drive. | |
| 2048 byte buffer mode | |
| If a disk is mounted with -o block=2048, data is copied straight from | |
| the drive data port to the buffer. Otherwise, the readahead buffer | |
| must be involved to hold the other 1K of data when a 1K block | |
| operation is done. Note that with 2048 byte blocks you cannot execute | |
| files from the CD. | |
| XA compatibility | |
| The driver should support XA disks for both the CDU31A and CDU33A. It | |
| does this transparently, the using program doesn't need to set it. | |
| Multi-Session | |
| A multi-session disk looks just like a normal disk to the user. Just | |
| mount one normally, and all the data should be there. A special | |
| thanks to Koen for help with this! | |
| Raw sector I/O | |
| Using the CDROMREADAUDIO it is possible to read raw audio and data | |
| tracks. Both operations return 2352 bytes per sector. On the data | |
| tracks, the first 12 bytes is not returned by the drive and the value | |
| of that data is indeterminate. |