cli: Add new `config' CLI for status/config registers

Add a new CLI mode to query and update status and configuration
registers of SPI NOR chips.  Programmer initialization and chip
initialization works the same as with the classic CLI (`-p' and
`-c' options). There are two commands `get' and `set' where the
former is implied if no command is given. For a start, only the
`quad-enable' bit can be accessed  (for chips that advertise it
in the database).

The `--temporary' option  allows to use a volatile write status
register command if the flash chip supports it. So changes made
with this option will not be written to flash and are lost when
the chip is reset.

For instance, the quad-enable bit can then be queried like this

  $ flashprog config get -p ch341a_spi quad-enable

or written with

  $ flashprog config set -p ch341a_spi quad-enable 1

or

  $ flashprog config set -p ch341a_spi --temporary quad-enable 1

Change-Id: I6b9d26c67e6ad65be5df367d2db7942bb98f27ac
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.sourcearcade.org/c/flashprog/+/195
diff --git a/flashprog-config.8.tmpl b/flashprog-config.8.tmpl
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+.\" Load the www device when using groff; provide a fallback for groff's MTO macro that formats email addresses.
+.ie \n[.g] \
+.  mso www.tmac
+.el \{
+.  de MTO
+     \\$2 \(la\\$1 \(ra\\$3 \
+.  .
+.\}
+.\" Create wrappers for .MTO and .URL that print only text on systems w/o groff or if not outputting to a HTML
+.\" device. To that end we need to distinguish HTML output on groff from other configurations first.
+.nr groffhtml 0
+.if \n[.g] \
+.  if "\*[.T]"html" \
+.    nr groffhtml 1
+.\" For code reuse it would be nice to have a single wrapper that gets its target macro as parameter.
+.\" However, this did not work out with NetBSD's and OpenBSD's groff...
+.de URLB
+.  ie (\n[groffhtml]==1) \{\
+.    URL \\$@
+.  \}
+.  el \{\
+.    ie "\\$2"" \{\
+.      BR "\\$1" "\\$3"
+.    \}
+.    el \{\
+.      RB "\\$2 \(la" "\\$1" "\(ra\\$3"
+.    \}
+.  \}
+..
+.de MTOB
+.  ie (\n[groffhtml]==1) \{\
+.    MTO \\$@
+.  \}
+.  el \{\
+.    ie "\\$2"" \{\
+.      BR "\\$1" "\\$3"
+.    \}
+.    el \{\
+.      RB "\\$2 \(la" "\\$1" "\(ra\\$3"
+.    \}
+.  \}
+..
+.TH FLASHPROG-CONFIG 8 "@MAN_DATE@" "flashprog-config-@VERSION@" "@MAN_DATE@"
+.SH NAME
+flashprog-config \- read and write status and configuration registers of flash chips
+.SH SYNOPSIS
+.I flashprog config \fR[\fIget\fR] <options> <setting>
+.br
+.I flashprog config \ set \ \fR<options> [\fB\-\-temporary\fR] <setting> <value>
+.sp
+Where generic <options> are:
+.RS 4
+\fB\-p\fR <programmername>[:<parameters>] [\fB\-c\fR <chipname>]
+.br
+[\fB\-V\fR[\fBV\fR[\fBV\fR]]] [\fB-o\fR <logfile>] [\fB\-h\fR]
+.RE
+
+.SH DESCRIPTION
+.B flashprog-config
+is a utility for reading and writing status and configuration register
+bits of flash chips. Currently, it supports only SPI NOR chips.
+
+.SH OPERATIONS
+You can specify one of
+.BR get " or " set ", "
+or no operation which defaults to reading a setting.
+.PP
+.BR get " <setting>"
+.RS 4
+Read and print the value of the given setting. See
+.BR SETTINGS " below."
+.RE
+.PP
+.BR set " [" \-\-temporary "] <setting> <value>"
+.RS 4
+Write the given value to the setting. See
+.BR SETTINGS " and " VALUES " below."
+.sp
+When the
+.B \-\-temporary
+option is provided, flashprog will attempt to write a temporary
+value that is not stored to flash. This requires special support
+by the flash chip for a volatile write status register command.
+The new value will be lost upon reset of the flash chip. Hence,
+it is futile to use this with external programmers that toggle
+power to the flash chip (e.g. Dediprog).
+.RE
+
+.SH SETTINGS
+.PP
+.B qe, quad-enable
+.RS 4
+SPI NOR flash chips often support muxing some of their pins (usually
+/WP and /HOLD) with additional i/o lines. This enables them to transfer
+four bits at once when the
+.B quad-enable
+bit is set.
+.RE
+
+.SH VALUES
+.PP
+.BR false ", " true
+.RS 4
+The values
+.BR false " and " true
+will be converted to
+.BR 0 " and " 1
+respectively.
+.RE
+.PP
+.RB "natural numbers: " 0 ", " 1 ", ..."
+.RS 4
+When natural numbers are given, the least-significant bits of their
+binary representation will be written to a setting.
+.RE
+
+.SH OPTIONS
+All operations require the
+.B -p/--programmer
+option to be used (please see
+.MR flashprog 8
+for more information on programmer support and parameters).
+.PP
+.BR \-p ", " \-\-programmer " <name>[" : "<parameter>[" , "<parameter>]...]"
+.RS 4
+Specify the programmer device. This is mandatory for all operations.
+Please see the
+.MR flashprog 8
+manual for a list of currently supported programmers and their parameters.
+.RE
+.PP
+.BR \-c ", " \-\-chip " <chipname>"
+.RS 4
+Probe only for the specified flash ROM chip. This option takes the chip name as
+printed by
+.B "flashprog \-L"
+without the vendor name as parameter. Please note that the chip name is
+case sensitive.
+.RE
+.PP
+.BR \-V ", " \-\-verbose
+.RS 4
+More verbose output. This option can be supplied multiple times
+(max. 3 times, i.e.
+.BR \-VVV )
+for even more debug output.
+.RE
+.PP
+.BR \-o ", " \-\-output " <logfile>"
+.RS 4
+Save the full debug log to
+.BR <logfile> .
+If the file already exists, it will be overwritten. This is the recommended
+way to gather logs from flashprog because they will be verbose even if the
+on-screen messages are not verbose and don't require output redirection.
+.RE
+.PP
+.BR \-h ", " \-\-help
+.RS 4
+Show a help text and exit.
+.RE
+.PP
+.BR \-\-temporary
+.RS 4
+Try to use a volatile write status register command. See
+.BR set " under " OPERATIONS " above."
+.RE
+
+.SH EXAMPLES
+To read the
+.B quad-enable
+setting of the internal BIOS flash:
+.sp
+.RS 2
+.B flashprog config -p internal quad-enable
+.sp
+.RE
+or
+.sp
+.RS 2
+.B flashprog config get -p internal quad-enable
+.sp
+.RE
+To temporarily set the
+.B quad-enable
+bit of a chip connected to an FT4222H:
+.sp
+.RS 2
+.B flashprog config set -p ft4222_spi --temporary quad-enable 1
+.RE
+
+.SH EXIT STATUS
+flashprog exits with 0 on success, 1 on most failures but with 3 if a call to mmap() fails.
+
+.SH REQUIREMENTS
+flashprog needs different access permissions for different programmers.
+See this section in the
+.MR flashprog 8
+manual for details.
+
+.SH BUGS
+You can report bugs, ask us questions or send success reports
+via our communication channels listed here:
+.URLB "https://www.flashprog.org/Contact" "" .
+.sp
+
+.SH LICENSE
+.B flashprog
+is covered by the GNU General Public License (GPL), version 2. Some files are
+additionally available under any later version of the GPL.
+
+.SH COPYRIGHT
+.br
+Please see the individual files.
+.PP
+This manual page was written by Nico Huber and is derived from the
+.MR flashprog 8
+manual. It is licensed under the terms of the GNU GPL (version 2 or later).
+
+.SH SEE ALSO
+.MR flashprog 8