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* state: remove unused arguments from state_new_from_node()Sascha Hauer2018-02-221-1/+1
| | | | | | | | state_new_from_node() has arguments describing the backend path. These are never used in barebox, the backend path is always derived from the device nodes backend description. Remove these arguments. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
* state: Do not load state during state_new_from_nodeSascha Hauer2017-03-311-0/+6
| | | | | | | | The caller of state_new_from_node() may have it's own ideas what to do when loading the state fails, so do not load it in the initialization function, but instead let the caller do it. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
* state: driver: handle EPROBE_DEFERSascha Hauer2016-10-201-2/+6
| | | | | | | | When state_new_from_node() returns -ENODEV that means that there is no device available for the node, so return -EPROBE_DEFER in this case and hope a device is there later. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
* state: Refactor state frameworkMarkus Pargmann2016-07-081-63/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* state: disable load commandEnrico Jorns2015-11-271-1/+0
| | | | | | | | | Explicitly loading environment is not required as it will be loaded if available during device probing Signed-off-by: Enrico Jorns <ejo@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
* state: use name of device node as name if alias is not availableMarc Kleine-Budde2015-11-271-1/+1
| | | | | | | | | | | Wihtout this patch, when using more than one state device an alias is mandatory, otherwise the there will be two state devices with the name state. This patch fixes the limitation by using the device node's name if no alias is defined. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
* state: make use of of_find_path_by_node() and add return -EPROBE_DEFER if ↵Marc Kleine-Budde2015-11-271-22/+9
| | | | | | | | device is not available Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
* state: backend: support phandle and of_path referencesMarc Kleine-Budde2015-05-151-14/+58
| | | | | | | | | | | This patch improves the backend property, it can be either a phandle or a of_path. During probe() of the state driver the backend property is dereferenced and the resulting of_path is saved in the state context. In a later patch it will be used to generate a phandle reference to the backend during DT fixup. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
* of_path: of_find_path(): add possibility to return .bb deviceMarc Kleine-Budde2015-04-231-1/+1
| | | | | | | | | This patch adds a flags argument to the of_find_path() function. The only flag defined for now is OF_FIND_PATH_FLAGS_BB. When used on NAND devices, the function returns the bad block aware device (the ".bb" device). Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
* state: add framework for persistent state handlingSascha Hauer2015-03-121-0/+81
This patch adds a framework to describe, access, store and restore a set of variables. A state variable set can be fully described in a devicetree node. This node could be part of the regular devicetree blob or it could be an extra devicetree solely for the state. The state variable set contains variables of different types and a place to store the variable set. For more information see: Documentation/devicetree/bindings/barebox/barebox,state.rst Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Jan Luebbe <jlu@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>