ide: add CS5536 host driver (v3)

This is a port of libata's pata_cs5536.c (written by Martin K. Petersen)
to IDE subsystem.

Changes done while at it:

* Reprogram PIO/MWDMA timings if needed before and after DMA transfer
  (chipset uses shared PIO/MWDMA timings).

* Fix cable detection to report 80-wires cable if BIOS set it for any
  device on a port (IDE core will do drive-side cable detection later).

* Don't disable UDMA while programming PIO timings.

* Simplify PCI/MSR support.

Pros of having IDE host driver in addition to libata's one:

* IDE is much lighter than SCSI+libata, the host driver itself is also
  a bit smaller:

   text    data     bss     dec     hex filename
   1261     496       4    1761     6e1 drivers/ata/pata_cs5536.o
   1242     128       4    1374     55e drivers/ide/cs5536.o

* This allows use of IDE features which are unavailable under libata.

v2:
* Fixes per review from Sergei:
  - simplify dependency check in Kconfig
  - use IDE_DRV_MASK also for ->drive_data
  - disable UDMA when programming MWDMA
  - program new DTC timings only when necessary
  - fix printk() level in cs5536_init_one()

* Fix patch description according to comments from Alan and Sergei.

v3:
* Smarter masking of UDMA bits per Sergei's suggestion.

Cc: Martin K. Petersen <mkp@mkp.net>
Cc: Karl Auerbach <karl@iwl.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/ide/Kconfig b/drivers/ide/Kconfig
index b1c6f68d98ce..3dad2299d9c5 100644
--- a/drivers/ide/Kconfig
+++ b/drivers/ide/Kconfig
@@ -465,6 +465,16 @@ config BLK_DEV_CS5535
 
           It is safe to say Y to this question.
 
+config BLK_DEV_CS5536
+        tristate "CS5536 chipset support"
+        depends on X86_32
+        select BLK_DEV_IDEDMA_PCI
+        help
+          This option enables support for the AMD CS5536
+          companion chip used with the Geode LX processor family.
+
+          If unsure, say N.
+
 config BLK_DEV_HPT366
         tristate "HPT36X/37X chipset support"
         select BLK_DEV_IDEDMA_PCI