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| >Video for Linux Two API Specification: Revision 0.24</TH |
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| ><H1 |
| ><A |
| NAME="VIDIOC-G-CHIP-IDENT" |
| ></A |
| >ioctl VIDIOC_G_CHIP_IDENT</H1 |
| ><DIV |
| CLASS="REFNAMEDIV" |
| ><A |
| NAME="AEN9808" |
| ></A |
| ><H2 |
| >Name</H2 |
| >VIDIOC_G_CHIP_IDENT -- Identify the chips on a TV card</DIV |
| ><DIV |
| CLASS="REFSYNOPSISDIV" |
| ><A |
| NAME="AEN9811" |
| ></A |
| ><H2 |
| >Synopsis</H2 |
| ><DIV |
| CLASS="FUNCSYNOPSIS" |
| ><P |
| ></P |
| ><A |
| NAME="AEN9812" |
| ></A |
| ><P |
| ><CODE |
| ><CODE |
| CLASS="FUNCDEF" |
| >int ioctl</CODE |
| >(int fd, int request, struct v4l2_chip_ident |
| *argp);</CODE |
| ></P |
| ><P |
| ></P |
| ></DIV |
| ></DIV |
| ><DIV |
| CLASS="REFSECT1" |
| ><A |
| NAME="AEN9822" |
| ></A |
| ><H2 |
| >Arguments</H2 |
| ><P |
| ></P |
| ><DIV |
| CLASS="VARIABLELIST" |
| ><DL |
| ><DT |
| ><CODE |
| CLASS="PARAMETER" |
| >fd</CODE |
| ></DT |
| ><DD |
| ><P |
| >File descriptor returned by <A |
| HREF="r14090.htm" |
| ><CODE |
| CLASS="FUNCTION" |
| >open()</CODE |
| ></A |
| >.</P |
| ></DD |
| ><DT |
| ><CODE |
| CLASS="PARAMETER" |
| >request</CODE |
| ></DT |
| ><DD |
| ><P |
| >VIDIOC_G_CHIP_IDENT</P |
| ></DD |
| ><DT |
| ><CODE |
| CLASS="PARAMETER" |
| >argp</CODE |
| ></DT |
| ><DD |
| ><P |
| ></P |
| ></DD |
| ></DL |
| ></DIV |
| ></DIV |
| ><DIV |
| CLASS="REFSECT1" |
| ><A |
| NAME="AEN9842" |
| ></A |
| ><H2 |
| >Description</H2 |
| ><DIV |
| CLASS="NOTE" |
| ><BLOCKQUOTE |
| CLASS="NOTE" |
| ><P |
| ><B |
| >Experimental: </B |
| >This is an <A |
| HREF="x16453.htm" |
| >experimental</A |
| > interface and may change in |
| the future.</P |
| ></BLOCKQUOTE |
| ></DIV |
| ><P |
| >For driver debugging purposes this ioctl allows test |
| applications to query the driver about the chips present on the TV |
| card. Regular applications should not use it. When you found a chip |
| specific bug, please contact the Video4Linux mailing list (<A |
| HREF="https://listman.redhat.com/mailman/listinfo/video4linux-list" |
| TARGET="_top" |
| >https://listman.redhat.com/mailman/listinfo/video4linux-list</A |
| >) |
| so it can be fixed.</P |
| ><P |
| >To query the driver applications must initialize the |
| <CODE |
| CLASS="STRUCTFIELD" |
| >match_type</CODE |
| > and |
| <CODE |
| CLASS="STRUCTFIELD" |
| >match_chip</CODE |
| > fields of a struct <A |
| HREF="r9804.htm#V4L2-CHIP-IDENT" |
| >v4l2_chip_ident</A |
| > |
| and call <CODE |
| CLASS="CONSTANT" |
| >VIDIOC_G_CHIP_IDENT</CODE |
| > with a pointer to |
| this structure. On success the driver stores information about the |
| selected chip in the <CODE |
| CLASS="STRUCTFIELD" |
| >ident</CODE |
| > and |
| <CODE |
| CLASS="STRUCTFIELD" |
| >revision</CODE |
| > fields. On failure the structure |
| remains unchanged.</P |
| ><P |
| >When <CODE |
| CLASS="STRUCTFIELD" |
| >match_type</CODE |
| > is |
| <CODE |
| CLASS="CONSTANT" |
| >V4L2_CHIP_MATCH_HOST</CODE |
| >, |
| <CODE |
| CLASS="STRUCTFIELD" |
| >match_chip</CODE |
| > selects the nth non-I<SUP |
| >2</SUP |
| >C chip |
| on the TV card. You can enumerate all chips by starting at zero and |
| incrementing <CODE |
| CLASS="STRUCTFIELD" |
| >match_chip</CODE |
| > by one until |
| <CODE |
| CLASS="CONSTANT" |
| >VIDIOC_G_CHIP_IDENT</CODE |
| > fails with an <SPAN |
| CLASS="ERRORCODE" |
| >EINVAL</SPAN |
| > error code. |
| Drivers may also interpret <CODE |
| CLASS="STRUCTFIELD" |
| >match_chip</CODE |
| > as a |
| random ID, but we recommend against that. The number zero always |
| selects the host chip, e. g. the chip connected to the PCI bus.</P |
| ><P |
| >When <CODE |
| CLASS="STRUCTFIELD" |
| >match_type</CODE |
| > is |
| <CODE |
| CLASS="CONSTANT" |
| >V4L2_CHIP_MATCH_I2C_DRIVER</CODE |
| >, |
| <CODE |
| CLASS="STRUCTFIELD" |
| >match_chip</CODE |
| > contains a driver ID as defined |
| in the <TT |
| CLASS="FILENAME" |
| >linux/i2c-id.h</TT |
| > header file. For instance |
| <CODE |
| CLASS="CONSTANT" |
| >I2C_DRIVERID_SAA7127</CODE |
| > will match any chip |
| supported by the saa7127 driver, regardless of its I<SUP |
| >2</SUP |
| >C bus address. |
| When multiple chips supported by the same driver are present, the |
| ioctl will return <CODE |
| CLASS="CONSTANT" |
| >V4L2_IDENT_AMBIGUOUS</CODE |
| > in the |
| <CODE |
| CLASS="STRUCTFIELD" |
| >ident</CODE |
| > field.</P |
| ><P |
| >When <CODE |
| CLASS="STRUCTFIELD" |
| >match_type</CODE |
| > is |
| <CODE |
| CLASS="CONSTANT" |
| >V4L2_CHIP_MATCH_I2C_ADDR</CODE |
| >, |
| <CODE |
| CLASS="STRUCTFIELD" |
| >match_chip</CODE |
| > selects a chip by its 7 bit |
| I<SUP |
| >2</SUP |
| >C bus address.</P |
| ><P |
| >On success, the <CODE |
| CLASS="STRUCTFIELD" |
| >ident</CODE |
| > field will |
| contain a chip ID from the Linux |
| <TT |
| CLASS="FILENAME" |
| >media/v4l2-chip-ident.h</TT |
| > header file, and the |
| <CODE |
| CLASS="STRUCTFIELD" |
| >revision</CODE |
| > field will contain a driver |
| specific value, or zero if no particular revision is associated with |
| this chip.</P |
| ><P |
| >When the driver could not identify the selected chip, |
| <CODE |
| CLASS="STRUCTFIELD" |
| >ident</CODE |
| > will contain |
| <CODE |
| CLASS="CONSTANT" |
| >V4L2_IDENT_UNKNOWN</CODE |
| >. When no chip matched |
| <CODE |
| CLASS="STRUCTFIELD" |
| >match_type</CODE |
| > and |
| <CODE |
| CLASS="STRUCTFIELD" |
| >match_chip</CODE |
| >, the ioctl will succeed but the |
| <CODE |
| CLASS="STRUCTFIELD" |
| >ident</CODE |
| > field will contain |
| <CODE |
| CLASS="CONSTANT" |
| >V4L2_IDENT_NONE</CODE |
| >. If multiple chips matched, |
| <CODE |
| CLASS="STRUCTFIELD" |
| >ident</CODE |
| > will contain |
| <CODE |
| CLASS="CONSTANT" |
| >V4L2_IDENT_AMBIGUOUS</CODE |
| >. In all these cases the |
| <CODE |
| CLASS="STRUCTFIELD" |
| >revision</CODE |
| > field remains unchanged.</P |
| ><P |
| >This ioctl is optional, not all drivers may support it. It |
| was introduced in Linux 2.6.21.</P |
| ><P |
| >We recommended the <SPAN |
| CLASS="APPLICATION" |
| >v4l2-dbg</SPAN |
| > |
| utility over calling this ioctl directly. It is available from the |
| LinuxTV v4l-dvb repository; see <A |
| HREF="http://linuxtv.org/repo/" |
| TARGET="_top" |
| >http://linuxtv.org/repo/</A |
| > for |
| access instructions.</P |
| ><DIV |
| CLASS="TABLE" |
| ><A |
| NAME="V4L2-CHIP-IDENT" |
| ></A |
| ><P |
| ><B |
| >Table 1. struct <CODE |
| CLASS="STRUCTNAME" |
| >v4l2_chip_ident</CODE |
| ></B |
| ></P |
| ><TABLE |
| BORDER="0" |
| FRAME="void" |
| WIDTH="100%" |
| CLASS="CALSTABLE" |
| ><COL |
| WIDTH="25%" |
| TITLE="C1"><COL |
| WIDTH="25%" |
| TITLE="C2"><COL |
| WIDTH="50%" |
| TITLE="C3"><TBODY |
| VALIGN="TOP" |
| ><TR |
| ><TD |
| >__u32</TD |
| ><TD |
| ><CODE |
| CLASS="STRUCTFIELD" |
| >match_type</CODE |
| ></TD |
| ><TD |
| >See <A |
| HREF="r9804.htm#IDENT-CHIP-MATCH-TYPES" |
| >Table 2</A |
| > for a list of |
| possible types.</TD |
| ></TR |
| ><TR |
| ><TD |
| >__u32</TD |
| ><TD |
| ><CODE |
| CLASS="STRUCTFIELD" |
| >match_chip</CODE |
| ></TD |
| ><TD |
| >Match a chip by this number, interpreted according |
| to the <CODE |
| CLASS="STRUCTFIELD" |
| >match_type</CODE |
| > field.</TD |
| ></TR |
| ><TR |
| ><TD |
| >__u32</TD |
| ><TD |
| ><CODE |
| CLASS="STRUCTFIELD" |
| >ident</CODE |
| ></TD |
| ><TD |
| >A chip identifier as defined in the Linux |
| <TT |
| CLASS="FILENAME" |
| >media/v4l2-chip-ident.h</TT |
| > header file, or one of |
| the values from <A |
| HREF="r9804.htm#CHIP-IDS" |
| >Table 3</A |
| >.</TD |
| ></TR |
| ><TR |
| ><TD |
| >__u32</TD |
| ><TD |
| ><CODE |
| CLASS="STRUCTFIELD" |
| >revision</CODE |
| ></TD |
| ><TD |
| >A chip revision, chip and driver specific.</TD |
| ></TR |
| ></TBODY |
| ></TABLE |
| ></DIV |
| ><DIV |
| CLASS="TABLE" |
| ><A |
| NAME="IDENT-CHIP-MATCH-TYPES" |
| ></A |
| ><P |
| ><B |
| >Table 2. Chip Match Types</B |
| ></P |
| ><TABLE |
| BORDER="0" |
| FRAME="void" |
| WIDTH="100%" |
| CLASS="CALSTABLE" |
| ><COL |
| WIDTH="38%" |
| TITLE="C1"><COL |
| WIDTH="12%" |
| TITLE="C2"><COL |
| WIDTH="50%" |
| TITLE="C3"><TBODY |
| VALIGN="TOP" |
| ><TR |
| ><TD |
| ><CODE |
| CLASS="CONSTANT" |
| >V4L2_CHIP_MATCH_HOST</CODE |
| ></TD |
| ><TD |
| >0</TD |
| ><TD |
| >Match the nth chip on the card, zero for the |
| host chip. Does not match I<SUP |
| >2</SUP |
| >C chips.</TD |
| ></TR |
| ><TR |
| ><TD |
| ><CODE |
| CLASS="CONSTANT" |
| >V4L2_CHIP_MATCH_I2C_DRIVER</CODE |
| ></TD |
| ><TD |
| >1</TD |
| ><TD |
| >Match an I<SUP |
| >2</SUP |
| >C chip by its driver ID from the |
| <TT |
| CLASS="FILENAME" |
| >linux/i2c-id.h</TT |
| > header file.</TD |
| ></TR |
| ><TR |
| ><TD |
| ><CODE |
| CLASS="CONSTANT" |
| >V4L2_CHIP_MATCH_I2C_ADDR</CODE |
| ></TD |
| ><TD |
| >2</TD |
| ><TD |
| >Match a chip by its 7 bit I<SUP |
| >2</SUP |
| >C bus address.</TD |
| ></TR |
| ></TBODY |
| ></TABLE |
| ></DIV |
| ><DIV |
| CLASS="TABLE" |
| ><A |
| NAME="CHIP-IDS" |
| ></A |
| ><P |
| ><B |
| >Table 3. Chip Identifiers</B |
| ></P |
| ><TABLE |
| BORDER="0" |
| FRAME="void" |
| WIDTH="100%" |
| CLASS="CALSTABLE" |
| ><COL |
| WIDTH="38%" |
| TITLE="C1"><COL |
| WIDTH="12%" |
| TITLE="C2"><COL |
| WIDTH="50%" |
| TITLE="C3"><TBODY |
| VALIGN="TOP" |
| ><TR |
| ><TD |
| ><CODE |
| CLASS="CONSTANT" |
| >V4L2_IDENT_NONE</CODE |
| ></TD |
| ><TD |
| >0</TD |
| ><TD |
| >No chip matched.</TD |
| ></TR |
| ><TR |
| ><TD |
| ><CODE |
| CLASS="CONSTANT" |
| >V4L2_IDENT_AMBIGUOUS</CODE |
| ></TD |
| ><TD |
| >1</TD |
| ><TD |
| >Multiple chips matched.</TD |
| ></TR |
| ><TR |
| ><TD |
| ><CODE |
| CLASS="CONSTANT" |
| >V4L2_IDENT_UNKNOWN</CODE |
| ></TD |
| ><TD |
| >2</TD |
| ><TD |
| >A chip is present at this address, but the driver |
| could not identify it.</TD |
| ></TR |
| ></TBODY |
| ></TABLE |
| ></DIV |
| ></DIV |
| ><DIV |
| CLASS="REFSECT1" |
| ><A |
| NAME="AEN9981" |
| ></A |
| ><H2 |
| >Return Value</H2 |
| ><P |
| >On success <SPAN |
| CLASS="RETURNVALUE" |
| >0</SPAN |
| > is returned, on error <SPAN |
| CLASS="RETURNVALUE" |
| >-1</SPAN |
| > and the <CODE |
| CLASS="VARNAME" |
| >errno</CODE |
| > variable is set appropriately:</P |
| ><P |
| ></P |
| ><DIV |
| CLASS="VARIABLELIST" |
| ><DL |
| ><DT |
| ><SPAN |
| CLASS="ERRORCODE" |
| >EINVAL</SPAN |
| ></DT |
| ><DD |
| ><P |
| >The driver does not support this ioctl, or the |
| <CODE |
| CLASS="STRUCTFIELD" |
| >match_type</CODE |
| > is invalid.</P |
| ></DD |
| ></DL |
| ></DIV |
| ></DIV |
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