[CentOS] trying to build driver for hpt374 raid controler

I'm trying to build driver for hpt374 raid controler on a new installation of contOS
4.2 followin the instroctions in this thread
http://www.centos.org/modules/newbb/viewtopic.php?viewmode=flat&order=DESC&topic_id=223&forum=7

It says that I should run "yum install kernel-sourcecode" to get the files I need
and it will create the path /usr/src/linux-2.6.9-5.0.3.EL which is needed. (guess it
will be 2.6.9-22.EL in centOS 4.2)

But the output from yum is this:
[root at localhost hpt374]# yum install kernel-sourcecode
Setting up Install Process
Setting up repositories
update                    100% |=========================|  951 B    00:00
base                      100% |=========================| 1.1 kB    00:00
addons                    100% |=========================|  951 B    00:00
extras                    100% |=========================| 1.1 kB    00:00
Reading repository metadata in from local files
primary.xml.gz            100% |=========================| 9.8 kB    00:00
update    : ################################################## 28/28
Added 12 new packages, deleted 0 old in 0.15 seconds
Parsing package install arguments
No Match for argument: kernel-sourcecode
Nothing to do


I tried using /usr/src/kernels/2.6.9-22.EL-i686 as KERNELDIR but that doesn't work.

I tried "yum search /usr/src/linux" and "yum provides /usr/src/linux" with no result.

I installed everything from the 4 centOS CD's but none of the scsi.h located on the
system looks like the one I need as they don't define `SCSI_DISK0_MAJOR'.

---
/root/hpt374/hpt.c:38:18: scsi.h: No such file or directory
/root/hpt374/hpt.c: In function `get_bdev':
/root/hpt374/hpt.c:60: error: `SCSI_DISK0_MAJOR' undeclared (first use in this
function)
/root/hpt374/hpt.c:60: error: (Each undeclared identifier is reported only once
/root/hpt374/hpt.c:60: error: for each function it appears in.)
/root/hpt374/hpt.c:60: error: initializer element is not constant
/root/hpt374/hpt.c:60: error: (near initialization for `major[0]')
---

What I'm I missing ? and SORRY if it is something obvious, this is the first time
I'm trying to build a driver.

best regards
Ulrik