revert "x86, serial: convert legacy COM ports to platform devices"

Revert 7e92b4fc345f5b6f57585fbe5ffdb0f24d7c9b26.  It broke Sébastien Dugué's
machine and Jeff said (persuasively)

  This seems like it will break decades-long-working stuff, in favor of
  breaking new ground in our favorite area, "trusting the BIOS."

  It's just not worth it for serial ports, IMO.  Serial ports are something
  that just shouldn't break at this late stage in the game.  My new Intel
  platform boxes don't even have serial ports, so I question the value of
  messing with serial port probing even more...  because...  just wait a year,
  and your box won't have a serial port either!  :)

  I certainly don't object to the use of platform devices (or isa_driver),
  but the probe change seems questionable.  That's sorta analagous to
  rewriting the floppy driver probe routine.  Sure you could do it...  but why
  risk all that damage and go through debugging all over again?

  It seems clear from this report that we cannot, should not, trust BIOS for
  something (a) so simple and (b) that has been working for over a decade.

Much discussion ensued and we've decided to have another go at all of this.

Cc: Sébastien Dugué <sebastien.dugue@bull.net>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Adam Belay <ambx1@neo.rr.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Jeff Garzik <jeff@garzik.org>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Cc: Sascha Sommer <saschasommer@freenet.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/include/asm-i386/serial.h b/include/asm-i386/serial.h
index 57a4306cdf63..bd67480ca109 100644
--- a/include/asm-i386/serial.h
+++ b/include/asm-i386/serial.h
@@ -11,3 +11,19 @@
  * megabits/second; but this requires the faster clock.
  */
 #define BASE_BAUD ( 1843200 / 16 )
+
+/* Standard COM flags (except for COM4, because of the 8514 problem) */
+#ifdef CONFIG_SERIAL_DETECT_IRQ
+#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ)
+#define STD_COM4_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_AUTO_IRQ)
+#else
+#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST)
+#define STD_COM4_FLAGS ASYNC_BOOT_AUTOCONF
+#endif
+
+#define SERIAL_PORT_DFNS                        \
+        /* UART CLK   PORT IRQ     FLAGS        */                      \
+        { 0, BASE_BAUD, 0x3F8, 4, STD_COM_FLAGS },      /* ttyS0 */     \
+        { 0, BASE_BAUD, 0x2F8, 3, STD_COM_FLAGS },      /* ttyS1 */     \
+        { 0, BASE_BAUD, 0x3E8, 4, STD_COM_FLAGS },      /* ttyS2 */     \
+        { 0, BASE_BAUD, 0x2E8, 3, STD_COM4_FLAGS },     /* ttyS3 */