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, 1 insertions, 0 deletions

diff --git a/include/linux/usb_usual.h b/include/linux/usb_usual.h
index 0a40dfa..d9a3bbe 100644
--- a/include/linux/usb_usual.h
+++ b/include/linux/usb_usual.h
@@ -85,6 +85,7 @@ enum { US_DO_ALL_FLAGS };
 #define US_SC_LOCKABLE	0x07		/* Password-protected */
 
 #define US_SC_ISD200    0xf0		/* ISD200 ATA */
+#define US_SC_CYP_ATACB 0xf1		/* Cypress ATACB */
 #define US_SC_DEVICE	0xff		/* Use device's value */
 
 /* Protocols */