.TH SMP_READ_GPIO "8" "August 2011" "smp_utils\-0.97" SMP_UTILS .SH NAME smp_read_gpio \- invoke READ GPIO REGISTER (ENHANCED) SMP function .SH SYNOPSIS .B smp_read_gpio [\fI\-\-count=CO\fR] [\fI\-\-enhanced\fR] [\fI\-\-help\fR] [\fI\-\-hex\fR] [\fI\-\-index=IN\fR] [\fI\-\-interface=PARAMS\fR] [\fI\-\-raw\fR] [\fI\-\-sa=SAS_ADDR\fR] [\fI\-\-type=TY\fR] [\fI\-\-verbose\fR] [\fI\-\-version\fR] \fISMP_DEVICE[,N]\fR .SH DESCRIPTION .\" Add any additional description here .PP Sends a SAS Serial Management Protocol (SMP) READ GPIO REGISTER or READ GPIO REGISTER ENHANCED function request to an SMP target. The SMP target is identified by the \fISMP_DEVICE\fR and the \fISAS_ADDR\fR. Depending on the interface, the \fISAS_ADDR\fR may be deduced from the \fISMP_DEVICE\fR. The mpt interface uses \fISMP_DEVICE\fR to identify a HBA (an SMP initiator) and needs the additional \fI,N\fR to differentiate between HBAs if there are multiple present. .PP This function is defined in SFF\-8485 ( see www.sffcommittee.com ) together with its corresponding WRITE GPIO REGISTER SMP function. The other SMP functions are defined in SAS documents at www.t10.org . SFF\-8485 defines a curious device called a "virtual SMP port" that lives in a host bus adapter (HBA) and allows SMP to manipulate the sideband signals on wide internal cables. To stop other initiators in a multi\-initiator domain from accessing those sideband signals, the virtual SMP (target) port is not indicated in a DISCOVER response. .PP For notes on the SMP READ GPIO REGISTER ENHANCED function see the section on the ENHANCED FUNCTION below. .SH OPTIONS Mandatory arguments to long options are mandatory for short options as well. .TP \fB\-c\fR, \fB\-\-count\fR=\fICO\fR where \fICO\fR is the register count. This is the number of (4 byte) registers to request. The default value is 1. .TP \fB\-E\fR, \fB\-\-enhanced\fR sends a READ GPIO REGISTER ENHANCED function request (default: send a READ GPIO REGISTER function request). .TP \fB\-h\fR, \fB\-\-help\fR output the usage message then exit. .TP \fB\-H\fR, \fB\-\-hex\fR output the response (less the CRC field) in hexadecimal. .TP \fB\-i\fR, \fB\-\-index\fR=\fIIN\fR where \fIIN\fR is the register index. This value is origin zero and its default value is 0. If the request succeeds, then \fI\-\-count=CO\fR registers starting from \fI\-\-index=IN\fR of the given \fI\-\-type=TY\fR should be in the response. .TP \fB\-I\fR, \fB\-\-interface\fR=\fIPARAMS\fR interface specific parameters. In this case "interface" refers to the path through the operating system to the SMP initiator. See the smp_utils man page for more information. .TP \fB\-r\fR, \fB\-\-raw\fR send the response (less the CRC field) to stdout in binary. All error messages are sent to stderr. .TP \fB\-s\fR, \fB\-\-sa\fR=\fISAS_ADDR\fR specifies the SAS address of the SMP target device. Typically this is an expander. This option may not be needed if the \fISMP_DEVICE\fR has the target's SAS address within it. The \fISAS_ADDR\fR is in decimal but most SAS addresses are shown in hexadecimal. To give a number in hexadecimal either prefix it with '0x' or put a trailing 'h' on it. .TP \fB\-t\fR, \fB\-\-type\fR=\fITY\fR where \fITY\fR is the register type. The default value is 0 (GPIO_CFG). If the request succeeds, then \fI\-\-count=CO\fR registers starting from \fI\-\-index=IN\fR of the given \fI\-\-type=TY\fR should be in the response. .TP \fB\-v\fR, \fB\-\-verbose\fR increase the verbosity of the output. Can be used multiple times .TP \fB\-V\fR, \fB\-\-version\fR print the version string and then exit. .SH ENHANCED FUNCTION In the technical review of SAS\-2 prior to standardization in this t10 document: 08\-212r8.pdf (page 871 or 552) there is a comment that the READ GPIO REGISTER and WRITE GPIO REGISTER function headers (i.e. first 4 bytes) do not comply with all the other SMP functions in SAS\-2. .PP There is a suggestion that enhanced variants be introduced in the next version of the SFF\-8485 document. If that ever happened then it has not been made public. In SAS\-2.1 both the READ and WRITE GPIO REGISTER functions have been made obsolete and the corresponding ENHANCED function numbers are "restricted" for SFF\-8485. .PP If the \fI\-\-enhanced\fR option is given then the ENHANCED function number is sent; the register type, index and count fields (1 byte each) are increased by two byte positions leaving enough space for a compliant SAS\-2 SMP header to be built. .SH EXAMPLES See "Examples" section in http://sg.danny.cz/sg/smp_utils.html .SH CONFORMING TO The SMP READ GPIO REGISTER (ENHANCED) function is defined in SFF\-8485 (see www.sffcommittee.com ) together with its corresponding WRITE GPIO REGISTER (ENHANCED) SMP function. .SH AUTHORS Written by Douglas Gilbert. .SH "REPORTING BUGS" Report bugs to . .SH COPYRIGHT Copyright \(co 2006\-2011 Douglas Gilbert .br This software is distributed under a FreeBSD license. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. .SH "SEE ALSO" .B smp_utils, smp_write_gpio(smp_utils)