Linux IR HOWTO: Hardware Supported by Linux/IrDA

8. Hardware Supported by Linux/IrDA

8.1 Obtaining Information about the Infrared Port in Laptops

To get the IrDA port of your laptop working with Linux/IrDA you may use StandardInfraRed (SIR) or FastInfraRed (FIR).

SIR

Up to 115.200bps, the infrared port emulates a serial port like the 16550A UART. This will be detected by the kernel serial driver at boot time, or when you load the serial module. If infrared support is enabled in the BIOS, for most laptops you will get a kernel message like:

Serial driver version 4.25 with no serial options enabled
ttyS00 at 0x03f8 (irq = 4) is a 16550A     #first serial port /dev/ttyS0
ttyS01 at 0x3000 (irq = 10) is a 16550A    #e.g. infrared port
ttyS02 at 0x0300 (irq = 3) is a 16550A     #e.g. PCMCIA modem port

FIR

If you want to use up to 4Mbps, your machine has to be equipped with a certain FIR chip. You need a certain Linux/IrDA driver to support this chip. Therefore you need exact information about the FIR chip. You may get this information in one of the following ways:

The irda-utils contain a program findchip now.
Read the specification of the machine, though it is very rare that you will find enough and reliable information there.
Try to find out whether the FIR chip is a PCI device. Do a cat /proc/pci . The according files for 2.2.x kernels are in /proc/bus/pci . Though often the PCI information is incomplete. You may find the latest information about PCI devices and vendor numbers in the kernel documentation usually in /usr/src/linux/Documentation or at the page of Craig Hart http://members.hyperlink.net.au/~chart . From kernel 2.1.82 on, you may use lspci from the pci-utils package, too.
Use the DOS tool CTPCI330.EXE provided in ZIP format by the German computer magazine CT ftp://www.heise.de/pub/ct/ctsi/ctpci330.zip . The information provided by this program is sometimes better than that provided by the Linux tools.

Try to get information about Plug-and-Play (PnP) devices. Though I didn't use them for this purpose yet, the isapnp tools, could be useful. At the page from Craig Hart I found this PNP IDs:

IBM0002   IBM Thinkpad Infrared Port
IBM0034   IBM Thinkpad Infrared Port
PNP0510   Generic IRDA-compatible device
PNP8294   IrDA Infrared NDIS driver (Microsoft-supplied)
PNP8389   Peer IrLAN infrared driver (Microsoft-supplied)

If you are running Linux-2.3.x and PCMCIA-CS-3.1.x, turn on the PnP BIOS in PCMCIA-CS. Then, do a lspnp -v (from Thomas Davis).
If you have installed the Linux/IrDA software load the FIR modules and watch the output of dmesg, whether FIR is detected or not.
Another way how to figure it out explained by Thomas Davis (modified by WH): "Dig through the FTP site of the vendor, find the Windows9x FIR drivers, and they have (for a SMC chip):
```
-rw-rw-r--   1 ratbert  ratbert       743 Apr  3  1997 smcirlap.inf 
-rw-rw-r--   1 ratbert  ratbert     17021 Mar 24  1997 smcirlap.vxd 
-rw-rw-r--   1 ratbert  ratbert      1903 Jul 18  1997 smcser.inf 
-rw-rw-r--   1 ratbert  ratbert     31350 Jun  7  1997 smcser.vxd 
```
If in doubt, always look for the .inf/.vxd drivers for Windows95. Windows95 doesn't ship with _ANY_ FIR drivers. (they are all third party, mostly from Counterpoint, who was assimilated by ESI)."

Also Thomas Davis found a package of small DOS utilities made by SMC. Look at http://www.smsc.com/ftppub/chips/appnote/ir_utils.zip . The package contains FINDCHIP.EXE. And includes a FIRSETUP.EXE utility that is supposed to be able to set all values except the chip address. Furthermore it contains BIOSDUMP.EXE, which produces this output:

Example 1 (from a COMPAQ Armada 1592DT)

     In current devNode:
           Size      = 78
           Handle    = 14
           ID        = 0x1105D041 = 'PNP0511' -- Generic IrDA SIR
           Types:  Base = 0x07, Sub = 0x00,  Interface = 0x02
                Comm. Device, RS-232, 16550-compatible
           Attribute = 0x80
                CAN be disabled
                CAN be configured
                BOTH Static & Dynamic configuration
      Allocated Resource Descriptor Block TAG's:
           TAG=0x47, Length=7 I/O Tag, 16-bit Decode
                                   Min=0x03E8, Max=0x03E8
                                   Align=0x00, Range=0x08
           TAG=0x22, Length=2 IRQ Tag, Mask=0x0010
           TAG=0x79, Length=1 END Tag, Data=0x2F

Result 1:

Irq Tag, Mask (bit mapped - ) = 0x0010 = 0000 0000 0000 0001 0000 so, it's IRQ 4. (start at 0, count up ..), so this is a SIR only device, at IRQ=4, IO=x03e8.

Example 2 (from an unknown machine)

     In current devNode:
          Size      = 529
          Handle    = 14
          ID        = 0x10F0A34D = 'SMCF010' -- SMC IrCC
          Types:  Base = 0x07, Sub = 0x00,  Interface = 0x02
               Comm. Device, RS-232, 16550-compatible
          Attribute = 0x80
               CAN be disabled
               CAN be configured
               BOTH Static & Dynamic configuration 

     Allocated Resource Descriptor Block TAG's:
          TAG=0x47, Length=7 I/O Tag, 16-bit Decode
                                  Min=0x02F8, Max=0x02F8
                                  Align=0x00, Range=0x08
          TAG=0x22, Length=2 IRQ Tag, Mask=0x0008
          TAG=0x47, Length=7 I/O Tag, 16-bit Decode
                                  Min=0x02E8, Max=0x02E8
                                  Align=0x00, Range=0x08
          TAG=0x2A, Length=2 DMA Tag, Mask=0x02, Info=0x08
          TAG=0x79, Length=1 END Tag, Data=0x00

Result 2:

a) it's a SMC IrCC chip

b) one portion is at 0x02f8, has an io-extent of 8 bytes; irq = 3

c) another portion is at 0x02e8, io-extent of 8 bytes; dma = 1 (0x02 =0000 0010)

Thomas Davis has placed some device information at http://www.jps.net/tadavis/irda/devids.txt .

WARNING: The package is not intended for the end user, and some of the utilities could be harmful. The only documentation in the package is in M$ Word format. Linux users may read this with catdoc, available at http://www.fe.msk.ru/~vitus/catdoc/ .

Use the Device Manager of Windows9x/NT or WINMSD (Windows NT Diagnostics) in Windows NT 4.0, WINMSD is quite useful, and a bit more informative than Windows9x's Device Manager.
You may also use the hardware surveys mentioned below.

And as a last ressort, you may even open the laptop and look at the writings at the chipsets itselfs. Here is an probably incomplete list of manufacturers: Chrystal, Hewlett Packard (HP, chipsets are marked HSDL), Hitachi, IBM, National Semi Conductor (NSC), NEC, Philips, Sharp, Standard Micro Systems Corporation (SMC/SMSC), Texas Instruments (TI), VLSI, Winbond. As an example of application circuits the HSDL-7001 (from a HP brochure, modified by WH):

    LEDs        Encode/Decode        SIR/FIR

   HSDL-1001    HSDL-7001          UART 16550/
                                  MicroController
   ______      ______________      ____________
  |      |    |              |    |            |
(||   TXD|<---|IR_TXD     TXD|<---|SOUT        |
  |      |    |              |    |            |
  |      |    |           RCV|--->|SIN         |
  |      |    |              |    |            |
(||   RCV|--->|IR_RCV  16XCLK|<---|BAUDOUT     |
  |      |    |          NRST|-+  |            |
   ------      --------------  |   ------------
                               V

8.2 Big Endian

Though the source is build to work with big endian machines, I didn't get any reports about actually using it. It would be interesting if it's actually working or not. You will probably need an IrDA dongle or something to test it.

i386 and alpha are little endian, arm can choose (but the NetWinder has been wired as a little endian machine). m68k, sparc and ppc are big-endian! mips can choose I think. If unsure, look in /usr/src/linux/asm/byteorder.h and check if it includes <linux/byteorder/big_endian.h> or <linux/byteorder/little_endian.h> .

8.3 SMP

Dag Brattli: "The problem ... has not been analyzed yet. It may be unsafe, and it may work pretty well. All upstream traffic should be safe (bh's), but downstream traffic _may_ be dangerous. I really don't know. ... All list operations irqueue.c in Linux-IrDA is currently SMP safe!". Please check the source code for the current status.

8.4 Hardware Surveys

There are some surveys about Linux and infrared capable devices in the WWW:

The Linux/IrDA Project - Hardware Survey at http://www.cs.uit.no/linux-irda/hardware.html
Takahide Higuchi at http://www.pluto.dti.ne.jp/~thiguchi/ir/product.html.This page is in japanese.
I have also set up a hardware survey at http://home.snafu.de/wehe. This list also contains information about infrared capable devices which are not mentioned here (mice, printers, remote control, transceivers, etc.).
To make this hardware survey list more valuable it is necessary to collect more information about the infrared devices in different hardware. You can help by sending me a short e-mail containing the exact name of the hardware you have and which type of infrared controller is used.

Please let me also know how well Linux/IrDA worked, at which tty, port and interrupt it works and the corresponding infrared device (e.g. printer, cellular phone) you use.

You can also help by contributing detailed technological information about some infrared devices, which is necessary to develope an according driver for Linux.

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