From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- .../DocBook/v4l/vidioc-dbg-g-chip-ident.xml | 275 +++++++++++++++++++++ 1 file changed, 275 insertions(+) create mode 100644 Documentation/DocBook/v4l/vidioc-dbg-g-chip-ident.xml (limited to 'Documentation/DocBook/v4l/vidioc-dbg-g-chip-ident.xml') diff --git a/Documentation/DocBook/v4l/vidioc-dbg-g-chip-ident.xml b/Documentation/DocBook/v4l/vidioc-dbg-g-chip-ident.xml new file mode 100644 index 00000000..4a09e203 --- /dev/null +++ b/Documentation/DocBook/v4l/vidioc-dbg-g-chip-ident.xml @@ -0,0 +1,275 @@ + + + ioctl VIDIOC_DBG_G_CHIP_IDENT + &manvol; + + + + VIDIOC_DBG_G_CHIP_IDENT + Identify the chips on a TV card + + + + + + int ioctl + int fd + int request + struct v4l2_dbg_chip_ident +*argp + + + + + + Arguments + + + + fd + + &fd; + + + + request + + VIDIOC_DBG_G_CHIP_IDENT + + + + argp + + + + + + + + + Description + + + Experimental + + This is an experimental interface and may change in +the future. + + + For driver debugging purposes this ioctl allows test +applications to query the driver about the chips present on the TV +card. Regular applications must not use it. When you found a chip +specific bug, please contact the linux-media mailing list (&v4l-ml;) +so it can be fixed. + + To query the driver applications must initialize the +match.type and +match.addr or match.name +fields of a &v4l2-dbg-chip-ident; +and call VIDIOC_DBG_G_CHIP_IDENT with a pointer to +this structure. On success the driver stores information about the +selected chip in the ident and +revision fields. On failure the structure +remains unchanged. + + When match.type is +V4L2_CHIP_MATCH_HOST, +match.addr selects the nth non-&i2c; chip +on the TV card. You can enumerate all chips by starting at zero and +incrementing match.addr by one until +VIDIOC_DBG_G_CHIP_IDENT fails with an &EINVAL;. +The number zero always selects the host chip, ⪚ the chip connected +to the PCI or USB bus. + + When match.type is +V4L2_CHIP_MATCH_I2C_DRIVER, +match.name contains the I2C driver name. +For instance +"saa7127" will match any chip +supported by the saa7127 driver, regardless of its &i2c; bus address. +When multiple chips supported by the same driver are present, the +ioctl will return V4L2_IDENT_AMBIGUOUS in the +ident field. + + When match.type is +V4L2_CHIP_MATCH_I2C_ADDR, +match.addr selects a chip by its 7 bit +&i2c; bus address. + + When match.type is +V4L2_CHIP_MATCH_AC97, +match.addr selects the nth AC97 chip +on the TV card. You can enumerate all chips by starting at zero and +incrementing match.addr by one until +VIDIOC_DBG_G_CHIP_IDENT fails with an &EINVAL;. + + On success, the ident field will +contain a chip ID from the Linux +media/v4l2-chip-ident.h header file, and the +revision field will contain a driver +specific value, or zero if no particular revision is associated with +this chip. + + When the driver could not identify the selected chip, +ident will contain +V4L2_IDENT_UNKNOWN. When no chip matched +the ioctl will succeed but the +ident field will contain +V4L2_IDENT_NONE. If multiple chips matched, +ident will contain +V4L2_IDENT_AMBIGUOUS. In all these cases the +revision field remains unchanged. + + This ioctl is optional, not all drivers may support it. It +was introduced in Linux 2.6.21, but the API was changed to the +one described here in 2.6.29. + + We recommended the v4l2-dbg +utility over calling this ioctl directly. It is available from the +LinuxTV v4l-dvb repository; see http://linuxtv.org/repo/ for +access instructions. + + + + struct <structname>v4l2_dbg_match</structname> + + &cs-ustr; + + + __u32 + type + See for a list of +possible types. + + + union + (anonymous) + + + + __u32 + addr + Match a chip by this number, interpreted according +to the type field. + + + + char + name[32] + Match a chip by this name, interpreted according +to the type field. + + + +
+ + + struct <structname>v4l2_dbg_chip_ident</structname> + + &cs-str; + + + struct v4l2_dbg_match + match + How to match the chip, see . + + + __u32 + ident + A chip identifier as defined in the Linux +media/v4l2-chip-ident.h header file, or one of +the values from . + + + __u32 + revision + A chip revision, chip and driver specific. + + + +
+ + + + Chip Match Types + + &cs-def; + + + V4L2_CHIP_MATCH_HOST + 0 + Match the nth chip on the card, zero for the + host chip. Does not match &i2c; chips. + + + V4L2_CHIP_MATCH_I2C_DRIVER + 1 + Match an &i2c; chip by its driver name. + + + V4L2_CHIP_MATCH_I2C_ADDR + 2 + Match a chip by its 7 bit &i2c; bus address. + + + V4L2_CHIP_MATCH_AC97 + 3 + Match the nth anciliary AC97 chip. + + + +
+ + + + Chip Identifiers + + &cs-def; + + + V4L2_IDENT_NONE + 0 + No chip matched. + + + V4L2_IDENT_AMBIGUOUS + 1 + Multiple chips matched. + + + V4L2_IDENT_UNKNOWN + 2 + A chip is present at this address, but the driver +could not identify it. + + + +
+ + + + &return-value; + + + + EINVAL + + The driver does not support this ioctl, or the +match_type is invalid. + + + + + + + -- cgit v1.2.3