From: Daniel Scheller <d.scheller@xxxxxxx> 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: linux-doc@xxxxxxxxxxxxxxx Cc: linux-s390@xxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Signed-off-by: Daniel Scheller <d.scheller@xxxxxxx> --- 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@xxxxxxxxxx> +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
