6028f7c4cd
This adds an interface to read the diagnostics of the local SFP transceiver
of an FCP-Channel from userspace. This comes in the form of new sysfs
entries that are attached to the CCW device representing the FCP
device. Each type of data gets its own sysfs entry; the whole collection of
entries is pooled into a new child-directory of the CCW device node:
"diagnostics".
Adds sysfs entries for:
* sfp_invalid: boolean value evaluating to whether the following 5
fields are invalid; {0, 1}; 1 - invalid
* temperature: transceiver temp.; unit 1/256°C;
range [-128°C, +128°C]
* vcc: supply voltage; unit 100μV; range [0, 6.55V]
* tx_bias: transmitter laser bias current; unit 2μA;
range [0, 131mA]
* tx_power: coupled TX output power; unit 0.1μW; range [0, 6.5mW]
* rx_power: received optical power; unit 0.1μW; range [0, 6.5mW]
* optical_port: boolean value evaluating to whether the FCP-Channel has
an optical port; {0, 1}; 1 - optical
* fec_active: boolean value evaluating to whether 16G FEC is active;
{0, 1}; 1 - active
* port_tx_type: nibble describing the port type; {0, 1, 2, 3};
0 - unknown, 1 - short wave,
2 - long wave LC 1310nm, 3 - long wave LL 1550nm
* connector_type: two bits describing the connector type; {0, 1};
0 - unknown, 1 - SFP+
This is only supported if the FCP-Channel in turn supports reporting the
SFP Diagnostic Data, otherwise read() on these new entries will return
EOPNOTSUPP (this affects only adapters older than FICON Express8S, on
Mainframe generations older than z14). Other possible errors for read()
include ENOLINK, ENODEV and ENOMEM.
With this patch the userspace-interface will only read data stored in
the corresponding "diagnostic buffer" (that was stored during completion
of an previous Exchange Port Data command). Implicit updating will
follow later in this series.
Link: https://lore.kernel.org/r/1f9cce7c829c881e7d71a3f10c5b57f3dd84ab32.1572018132.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.