ratp: Straighten ratp deregistration ...

There are some bugs in the error path when ratp initialization fails
half way through. Reusing the global ratp context which might be half
initialized makes the code hard to follow and hard to fix, so the
strategy is changed to always allocating a fresh ratp context and
returning -EBUSY when one exists already. We store in the context what
has been done in the initialization path and add a ratp_unregister()
which uses this information to tear down everything that has been
initialized.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/ratp'

poller: Give pollers a name ...

It helps debugging when pollers have a name, so give them one.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: Remove unnecessary poller_call() ...

poller_call() is called by is_timeout(), no need to do this again in a
timeout loop.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: Test if console exists before using it ...

Consoles can be unregistered, this happens for example when barebox
implements the barebox serial USB gadget. Before using the console
we have to explicitly test if the pointer is still valid each time.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

treewide: remove references to CREDITS ...

The CREDITS file was removed from barebox in 2015 by commit 6570288f2d97
("Remove the CREDITS file"). Remove references to it from several files.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: add more build dependencies ...

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

console: fix out-of-bounds read in dputc(/dev/*, ...) ...

Trying to output a single character via
	echo -a /dev/serial0-1
currently results in garbage output after the newline, because console.c's
fops_write discards the buffer length and passes the buffer to
(struct cdev)::puts which only handles NUL-terminated strings.

Fix this by amending (struct cdev)::puts with a new nbytes parameter,
which is correctly propagated. All this functions now return at most the
nbytes parameter they were passed in. This fixes __console_puts, which
used to count new lines twice in its return value.

Fixes: b4f55fcf35 ("console: expose consoles in devfs")
Cc: Bastian Krause <bst@pengutronix.de>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: fix use of %hu for printing int ...

While each of path_size and data_size is 16 bit in size, their sum may
exceed this. Also the type of the resulting expression is an int, thus
change the format specifier accordingly.

Signed-off-by: Ahmad Fatoum <ahmad@a3f.at>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

crc: import crc_itu_t() from kernel ...

Our cyc_crc16() function is the same function as crc_itu_t() in the
Linux kernel. Import and use crc_itu_t() from the Kernel for
consistency.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/lseek'

commands: Get rid of mem_rw_buf ...

There doesn't seem to be any good reason for all of the memory
commands (md, mw, etc.) to rely on a shared pre-allocated buffer
anymore. So, to simplify things, drop the shared buffer and adjust all
of the utilites to allocate needed memory.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

treewide: Introduce MAP_FAILED and replace ad-hoc constants with it ...

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: fix compile warnings ...

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/ratp'

ratp: select CMDLINE_EDITING ...

ratp seems to send special characters which are not handle correctly
without CDMLINE_EDITING. Without this config, commands run via ratp will
have an erratic behavior and/or incorrect output.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: fix incorrect whitespaces in method calls ...

This is a simple coding style fix to avoid the whitespace before the
open-parenthesis in method calls.

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: use pr_ macros to print messages ...

Following suggestions in other patch reviews, the RAPT commands are
updated to use pr_err() instead of plain printf() to report errors
to the user.

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: use __packed instead of the full form ...

Just a minor coding style change to follow the suggestions given in
patch reviews for other RATP commands.

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: implement support for GPIO commands ...

Introduce three new RATP commands that allow getting and setting GPIO
values as well as configuring the direction of the GPIO pins.

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: implement i2c read/write support ...

Introduce two new RATP commands that allow running i2c read/write
operations, very similar in format to the already existing md/mw
RATP commands.

The messages are defined with a fixed 16-bit long register field, but
it will only be treated as a 16-bit address if I2C_FLAG_WIDE_ADDRESS
is set in the message flags field. If this flag is unset, the start
register address is assumed 8-bit long.

If the message includes the I2C_FLAG_MASTER_MODE flag, the start
register field is ignored and a i2c master send/receive operation is
performed.

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: new reset command ...

E.g.:
    $ ./bbremote -v --port /dev/ttyUSB2 reset

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: new md and mw commands ...

This commit introduces support for running the md and mw commands
using the binary interface provided by RATP. This allows clients to
read and write memory files without needing to do custom string
parsing on the data returned by the console 'md' and 'mw' operations.

The request and response messages used for these new operations are
structured in the same way:

 * An initial fixed-sized section includes the fixed-sized
   variables (e.g. integers), as well as the size and offset of the
   variable-length variables.

 * After the initial fixed-sized section, the buffer is given, which
   contains the variable-length variables in the offsets previously
   defined and with the size previously defined.

The message also defines separately the offset of the buffer
w.r.t. the start of the message. The endpoint reading the message will
use this information to decide where the buffer starts. This allows to
extend the message format in the future without needing to break the
message API, as new fields can be appended to the fixed-sized section
as long as the buffer offset is also updated to report the new
position of the buffer.

E.g.:
    $ ./bbremote --port /dev/ttyUSB2 md /dev/pic_eeprom_rdu 0x107 5
    0000000000

    $ ./bbremote --port /dev/ttyUSB2 mw /dev/pic_eeprom_rdu 0x107 0102030405
    5 bytes written

    $ ./bbremote --port /dev/ttyUSB2 md /dev/pic_eeprom_rdu 0x107 5
    0102030405

    $ ./bbremote --port /dev/ttyUSB2 mw /dev/pic_eeprom_rdu 0x107 0000000000
    5 bytes written

    $ ./bbremote --port /dev/ttyUSB2 md /dev/pic_eeprom_rdu 0x107 5
    0000000000

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: use xstrndup() instead of a custom xmemdup_add_zero() ...

The console operations done via RATP expect strings, so just use
xstrndup() instead of defining a custom method.

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: implement getenv as a standard ratp command ...

Also, use xstrndup() instead of the custom xmemdup_add_zero() as we're
working with strings anyway.

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: implement ping as a standard ratp command ...

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: allow building without full console support ...

Make CONFIG_RATP a selectable config option, so that the user can
enable RATP support without explicitly needing to enable the full
console support over RATP (e.g. only for RATP FS or built-in command
support).

The full console can still be explicitly enabled with
CONFIG_CONSOLE_RATP.

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ratp: moved logic to its own subdirectory ...

We are going to add new RATP command implementations in separate files
within this subdirectory.

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>