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if ((pp = pccard_product_lookup(dev, wi_pccard_products,
sizeof(wi_pccard_products[0]), NULL)) != NULL) {
if (pp->pp_name != NULL)
device_set_desc(dev, pp->pp_name);
return (0);
return (ENXIO);
cbb1 pnpinfo vendor=0x104c device=0xac51 subvendor=0x1265 subdevice=0x0300 class=0x060700 at slot=10 function=1
unknown pnpinfo manufacturer=0x026f product=0x030c cisvendor="BUFFALO" cisproduct="WLI2-CF-S11" function_type=6 at function=0
/* Allied Telesis K.K. */
product ALLIEDTELESIS LA_PCM 0x0002 Allied Telesis LA-PCM
/* Archos */
product ARCHOS ARC_ATAPI 0x0043 MiniCD
product BUFFALO WLI_PCM_S11 0x0305 BUFFALO AirStation 11Mbps WLAN
product BUFFALO LPC3_CLT 0x030a BUFFALO LPC3-CLT Ethernet Adapter
product BUFFALO WLI_CF_S11G 0x030b BUFFALO AirStation 11Mbps CF WLAN
Adding a Device
But there is no entry for this particular card. Instead we find:
Chances are very good that the `NETGEAR_2` entry is really an OEM that NETGEAR purchased cards from and the author of support for those cards was unaware at the time that Netgear was using someone else's ID. These entries are fairly straightforward. The vendor keyword denotes the kind of line that this is, followed by the name of the vendor. This name will be repeated later in [.filename]#pccarddevs#, as well as used in the driver's match tables, so keep it short and a valid C identifier. A numeric ID in hex identifies the manufacturer. Do not add IDs of the form `0xffffffff` or `0xffff` because these are reserved IDs (the former is "no ID set" while the latter is sometimes seen in extremely poor quality cards to try to indicate "none"). Finally there is a string description of the company that makes the card. This string is not used in FreeBSD for anything but commentary purposes.
Chapter 16. PC Card
Device drivers know what devices they support. There is a table of supported devices in the kernel that drivers use to attach to a device.
Due to this practice, FreeBSD drivers usually rely on numeric IDs for device identification. Using numeric IDs and a centralized database complicates adding IDs and support for cards to the system. One must carefully check to see who really made the card, especially when it appears that the vendor who made the card might already have a different manufacturer ID listed in the central database. Linksys, D-Link, and NetGear are a number of US manufacturers of LAN hardware that often sell the same design. These same designs can be sold in Japan under names such as Buffalo and Corega. Often, these devices will all have the same manufacturer and product IDs.
Finally, some really low end devices do not contain manufacturer identification at all. These devices must be detected by matching the human readable CIS strings. While it would be nice if we did not need this method as a fallback, it is necessary for some very low end CD-ROM players and Ethernet cards. This method should generally be avoided, but a number of devices are listed in this section because they were added prior to the recognition of the OEM nature of the PC Card business. When adding new devices, prefer using the numeric method.
Format of [.filename]#pccarddevs#
Here we have a simple pccard probe routine that matches a few devices. As stated above, the name may vary (if it is not `foo_pccard_probe()` it will be `foo_pccard_match()`). The function `pccard_product_lookup()` is a generalized function that walks the table and returns a pointer to the first entry that it matches. Some drivers may use this mechanism to convey additional information about some cards to the rest of the driver, so there may be some variance in the table. The only requirement is that each row of the table must have a `struct pccard_product` as the first element.
If you are a FreeBSD src committer, and everything appears to be working, then you can commit the changes to the tree. However, there are some minor tricky things to be considered. [.filename]#pccarddevs# must be committed to the tree first. Then [.filename]#pccarddevs.h# must be regenerated and committed as a second step, ensuring that the right $FreeBSD$ tag is in the latter file. Finally, commit the additions to the driver.
Looking at the table `wi_pccard_products`, one notices that all the entries are of the form `PCMCIA_CARD(_foo_, _bar_, _baz_)`. The _foo_ part is the manufacturer ID from [.filename]#pccarddevs#. The _bar_ part is the product ID. _baz_ is the expected function number for this card. Many pccards can have multiple functions, and some way to disambiguate function 1 from function 0 is needed. You may see `PCMCIA_CARD_D`, which includes the device description from [.filename]#pccarddevs#. You may also see `PCMCIA_CARD2` and `PCMCIA_CARD2_D` which are used when you need to match both CIS strings and manufacturer numbers, in the "use the default description" and "take the description from pccarddevs" flavors.
Note that I have included a '`+`' in the line before the line that I added, but that is simply to highlight the line. Do not add it to the actual driver. Once you have added the line, you can recompile your kernel or module and test it. If the device is recognized and works, please submit a patch. If it does not work, please figure out what is needed to make it work and submit a patch. If the device is not recognized at all, you have done something wrong and should recheck each step.
Once these steps are complete, the card can be added to the driver. That is a simple operation of adding one line:
Original equipment manufacturers (OEMs) often develop a reference design for a PC Card product, then sell this design to other companies to market. Those companies refine the design, market the product to their target audience or geographic area, and put their own name plate onto the card. The refinements to the physical card are typically very minor, if any changes are made at all. To strengthen their brand, these vendors place their company name in the human readable strings in the CIS space, but leave the manufacturer and product IDs unchanged.
PC Card