From: Daniel Scheller <redacted>
drivers/media/pci/ddbridge exposes a few IOCTLs which are used by userspace
utilities to ie. update PCIe card's FPGA firmware.
The IOCTLs chosen are in the range 0xDD/0xE0 up to 0xDD/0xFF, with 0xDD as
sort of gimmick for "Digital Devices". To not conflict with the zfpc driver
the upper range (0xE0-0xFF) is used. It is not clear if and which IOCTL
numbers the zfpc driver really uses, from reading the sources at
drivers/s390/scsi/ I couldn't really determine if IOCTLs are in use at all.
Maybe the S390 maintainers can double-check or comment, thus Cc linux-s390.
The upstream dddvb driver currently exposes 12 IOCTLs from which we're
going to handle two at the moment (DDB_FLASHIO and DDB_ID), which is all
that's required to perform the FPGA update on this hardware. The
"reservation" of 32 IDs may seem way too much in this regard, however,
we'd like to be able to stay compatible with the upstream out-of-tree
driver as much as possible, so should any of the remaining 10 IOCTLs be
required at any time (or even more, should upstream add more in the
future), we can just add them into this range without any hassles or
without creating conflicts anywhere.
Cc: <redacted>
Cc: <redacted>
Cc: <redacted>
Signed-off-by: Daniel Scheller <redacted>
---
Documentation/ioctl/ioctl-number.txt | 1 +
1 file changed, 1 insertion(+)
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index 84bb74dcae12..feac1b56900b 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -334,6 +334,7 @@ Code Seq#(hex) Include File Comments
0xDB 00-0F drivers/char/mwave/mwavepub.h
0xDD 00-3F ZFCP device driver see drivers/s390/scsi/
<mailto:aherrman@de.ibm.com>
+0xDD E0-FF linux/ddbridge-ioctl.h
0xE5 00-3F linux/fuse.h
0xEC 00-01 drivers/platform/chrome/cros_ec_dev.h ChromeOS EC driver
0xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development)
--
2.16.1
--
To unsubscribe from this list: send the line "unsubscribe linux-doc" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html