USB: mass storage: emulation of sat scsi_pass_thru with ATACB

I have got a cypress usb-ide bridge and I would like to tune or monitor
my disk with tools like hdparm, hddtemp or smartctl.

My controller support a way to send raw ATA command to the disk with
something call atacb (see
http://download.cypress.com.edgesuite.net/design_resources/datasheets/contents/cy7c68300c_8.pdf).

Atacb support can be added for each application, but there is some disadvantages :
- all application need to be patched
- A race is possible if there other accesses, because the emulation can
be split in 2 atacb scsi transactions. One for sending the command, one
for reading the register (if ck_cond is set). 

I have implemented the emulation in usb-storage with a special proto_handler,
and an unsual entry.

Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
Signed-off-by: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/usb/storage/Kconfig b/drivers/usb/storage/Kconfig
index 05cfc8473bd2..d3e5f889f68d 100644
--- a/drivers/usb/storage/Kconfig
+++ b/drivers/usb/storage/Kconfig
@@ -145,6 +145,17 @@ config USB_STORAGE_KARMA
           on the resulting scsi device node returns the Karma to normal
           operation.
 
+config USB_STORAGE_CYPRESS_ATACB
+        bool "SAT emulation on Cypress USB/ATA Bridge with ATACB"
+        depends on USB_STORAGE
+        ---help---
+          Say Y here if you want to use SAT (ata pass through) on devices based
+          on the Cypress USB/ATA bridge supporting ATACB. This will allow you
+          to use tools to tune and monitor your drive (like hdparm or smartctl).
+
+          If you say no here your device will still work with the standard usb
+          mass storage class.
+
 config USB_LIBUSUAL
         bool "The shared table of common (or usual) storage devices"
         depends on USB