common: state: fix another alignment ...

Fixes: 7126dffd0be ("common: state: Add variable_type to state_variable")
Fixes: 6096a0cfa4a ("common: state: fix alignment")
Signed-off-by: Roland Hieber <rhi@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

common: state: fix alignment ...

Fixes: 7126dffd0be ("common: state: Add variable_type to state_variable")
Signed-off-by: Roland Hieber <rhi@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

state: remove unused function ...

state_find_type() is unused and doesn't have a prototype. Remove it.

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

common: state: use of_property_write_string() where appropriate ...

See commit b6089182316d ("treewide: Use of_property_write_string() where
appropriate").

Signed-off-by: Ulrich Ölmann <u.oelmann@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

common: state: Add variable type as enum ...

The variable_type struct holds a name of its type. Checking the type of
a variable with this string needs much resources.

This patch introduce a enum of the variable type for better type
checking.

Signed-off-by: Daniel Schultz <d.schultz@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

common: state: Add variable_type to state_variable ...

Add a pointer in state_variable to the corresponding variable_type array
element.

Signed-off-by: Daniel Schultz <d.schultz@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

param: make parameter functions more consistent ...

This patch creates a consitent set of device parameter functions.

With this we have: dev_add_param_<type><access>

"type" is one of: int32, uint32, int64, uint64, string, mac, ipv4, enum, bitmask
The improvement here is that we now can exactly specify the width of the
int type parameters and also correctly distinguish between signed and
unsigned variables which means that a variable no longer ends up with
INT_MAX when it's assigned -1.

"access" can be empty for regular read/write parameter, "_ro" for readonly
parameters which get their value from a variable pointer in the
background or "_fixed" for parameters which are set to a fixed value
(without a pointer in the background).

Some more exotic types are not (yet) implemented, like
dev_add_param_ip_ro.

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

state: remove unused variable type ...

enum state_variable_type is never used. Remove it.

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

Merge branch 'for-next/state'

state: fix indentation ...

Signed-off-by: Stefan Lengfeld <s.lengfeld@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

state: fix state is not saved when string variable is changed ...

The dirty flag was not set properly.

Signed-off-by: Stefan Lengfeld <s.lengfeld@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

state: consistently pass one type as private data to dev_add_param_* ...

The different dev_add_param_* calls all use different types as private
data. This is unnecessary, use struct state_variable * for all of them.

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

state: make locally used function static ...

state_set_dirty() is only used in one file, make it static.

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

state: Add state to state_variable ...

A state variable should know which state it belongs to. Add field
for it to struct state_variable.

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

state: Refactor state framework ...

The state framework grew organically over the time. Unfortunately the
architecture and abstractions disappeared during this period.

This patch refactors the framework to recreate the abstractions. The
main focus was the backend with its storage. The main use-case was to
offer better NAND support with less erase cycles and interchangeable
data formats (dtb,raw).

The general architecture now has a backend which consists of a data
format and storage. The storage consists of multiple storage buckets
each holding exactly one copy of the state data. A data format describes
a data serialization for the state framework. This can be either dtb or
raw. A storage bucket is a storage location which is used to store any
data. There is a (new) circular type which writes changes behind the
last written data and therefore reduces the number of erases. The other
type is a direct bucket which writes directly to a storage offset for
all non-erase storage.

Furthermore this patch splits up all classes into different files in a
subdirectory.

This is currently all in one patch as I can't see a good way to split
the changes up without having a non-working state framework in between.

The following diagram shows the new architecture roughly:

           .----------.
           |  state   |
           '----------'
                 |
                 |
                 v
  .----------------------------.
  |       state_backend        |
  |----------------------------|
  | + state_load(*state);      |
  | + state_save(*state);      |
  | + state_backend_init(...); |
  |                            |
  |                            |
  '----------------------------'
    |            |                   The format describes
    |            |                   how the state data
    |            '------------->     is serialized
    |   .--------------------------------------------.
    |   |      state_backend_format <INTERFACE>      |
    |   |--------------------------------------------|
    |   | + verify(*format, magic, *buf, len);       |
    |   | + pack(*format, *state, **buf, len);       |
    |   | + unpack(*format, *state, *buf, len);      |
    |   | + get_packed_len(*format, *state);         |
    |   | + free(*format);                           |
    |   '--------------------------------------------'
    |              ^                      ^
    |              *                      *
    |              *                      *
    |   .--------------------. .--------------------.
    |   | backend_format_dtb | | backend_format_raw |
    |   '--------------------' '--------------------'
    |
    |
    |
    v
.----------------------------------------------------------.
|                  state_backend_storage                   |
|----------------------------------------------------------|
| + init(...);                                             |
| + free(*storage);                                        |
| + read(*storage, *format, magic, **buf, *len, len_hint); |
| + write(*storage, *buf, len);                            |
| + restore_consistency(*storage, *buf, len);              |
'----------------------------------------------------------'
                              |
     The backend storage is responsible to manage multiple
     data copies and distribute them onto several buckets.
     Read data is verified against the given format to
     ensure that the read data is correct.
                              |
                              |
                              |
                              |
                              |
                              v
        .------------------------------------------.
        | state_backend_storage_bucket <INTERFACE> |
        |------------------------------------------|
        | + init(*bucket);                         |
        | + write(*bucket, *buf, len);             |
        | + read(*bucket, **buf, len_hint);        |
        | + free(*bucket);                         |
        '------------------------------------------'
                      ^     ^      ^
                     *      *       *
                    *       *        *
 A storage bucket represents*exactly one data copy at one
 data location. A circular b*cket writes any new data to
 the end of the bucket (for *educed erases on NAND). A
 direct bucket directly writ*s at one location.
               *            *             *
              *             *              *
             *              *               *
 .-----------------------.  *  .-------------------------.
 | backend_bucket_direct |  *  | backend_bucket_circular |
 '-----------------------'  *  '-------------------------'
             ^              *               ^
             |              *               |
             |              *               |
             |              *               |
             |  .-----------------------.   |
             '--| backend_bucket_cached |---'
                '-----------------------'
             A backend_bucket_cached is a transparent
             bucket that directly uses another bucket
             as backend device and caches all accesses.

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