Simplifications:

- Remove all the code intended to deal with experimental
  C1010 revisions. This code got useless due to commercial
  chip revisions having been fixed.
Fixes:
- Rewrite/rework the WSR condition handling.
  Previous drivers snooped on the BUS through the SBDL IO
  register and this has been discovered to trigger a spurious
  SCSI parity error when WSR had been set by chip and cleared
  by SCRIPTS prior to reading SBDL bit [0...7].
  On the other hand, the C1010 does not use the SWIDE register
  when synchronous data transfers are taking place and
  requires a CHMOV (1) WHEN DATA_IN to be performed in order
  to move to memory the residual byte when WSR is set and
  the residual byte is useful data.
  BTW, the new WSR handling by the driver is simpler.
- No longer attempt to read from SCRIPTS the SBDL register.
  This is intended to avoid to be victimized again by any other
  issue regarding the handling of this register by 8xx chips.
Miscellaneous:
- The driver is now able to handle the WSR + IGN RESIDUE
  condition at the end of a DATA IN I/O without need of a
  programmed interrupt. It is a minor? optimization.
- A few other minor cosmetic changes.

This driver version fixes notably a permanent SCSI parity
error condition at boot that can be triggerred due to recent
changes in cam_xpt.c between 1.79 and 1.80.
Changes in CAM/XPT are fine, but the new handling of the full
INQUIRY may trigger the driver problem when a target returned
an odd value in the `additionnal length' field of the INQUIRY
response.

The diff against previous driver version is large, but it
consists approximatively in:
- 350 lignes removed and not compiled in previous drivers
  (They addressed experimental C1010 revisions)
- 250 lignes added or changed, half being comments or empty
  lines.
So, in fact, the real changes are about 120 lines of source.
About 80 lines address SCRIPTS changes and about 40 lines
address C code changes.

Approved by: jkh

New WSR handling reviewed by Pamela Delaney <pam.delaney@lsil.com>
(For back-porting to Linux sym53c8xx driver 1.6x series)

sys/dev/sym/sym_conf.h

@@ -66,22 +66,6 @@
  *-------------------------------------------------------------------
  */
 
-/*
- *  Support for earliest LSI53C1010 boards.
- *
- *  This option enables work-arounds for the experimental 
- *  C1010 chips revision 0 to work in DT mode.
- *  Since, officially supported chips (B0 stepping and later)
- *  have been fixed, nobody, except driver maintainers,
- *  should ever needed this option to have been defined.
- *  This option and the code it addresses will be removed 
- *  from the source in some later version of the driver.
- *  By the way, the 53C1010 B0 stepping (rev. 1) has been 
- *  tested ok with Ultra3 DT data transfers using this driver,
- *  without these work-arounds being enabled.
- */
-/* #define	SYM_CONF_BROKEN_U3EN_SUPPORT */
-
 /*
  *  Use Normal IO instead of MMIO.
  */