kernel/include/linux/mtd/nand.h, branch linux-5.11.y

mtd: nand: Add helpers to manage ECC engines and configurations

2020-12-10T21:37:30Z

Add the logic in the NAND core to find the right ECC engine depending on the NAND chip requirements and the user desires. Right now, the choice may be made between (more will come): * software Hamming * software BCH * on-die (SPI-NAND devices only) Once the ECC engine has been found, the ECC engine must be configured. Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20201001102014.20100-2-miquel.raynal@bootlin.com

mtd: nand: Let on-die ECC engines be retrieved from the NAND core

2020-12-10T21:37:30Z

Before making use of the ECC engines, we must retrieve them. Add the necessary boilerplate. Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20200930154109.3922-5-miquel.raynal@bootlin.com

mtd: nand: Let software ECC engines be retrieved from the NAND core

2020-12-10T21:37:30Z

Before making use of the ECC engines, we must retrieve them. Add the boilerplate for the ones already available: software engines (Hamming and BCH). Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20200929230124.31491-21-miquel.raynal@bootlin.com

mtd: nand: ecc-hamming: Create the software Hamming engine

2020-12-10T21:37:30Z

Let's continue introducing the generic ECC engine abstraction in the NAND subsystem by instantiating a second ECC engine: software Hamming. Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20200929230124.31491-20-miquel.raynal@bootlin.com

mtd: nand: ecc-bch: Create the software BCH engine

2020-12-10T21:37:26Z

Let's continue introducing the generic ECC engine abstraction in the NAND subsystem by instantiating a first ECC engine: the software BCH one. While at it, make a very tidy ecc_sw_bch_init() function and move all the sanity checks and user input management in nand_ecc_sw_bch_init_ctx(). This second helper will be called from the raw RAND core. Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20200929230124.31491-10-miquel.raynal@bootlin.com

mtd: nand: ecc: Add an I/O request tweaking mechanism

2020-11-30T08:27:32Z

Currently, BCH and Hamming engine are sharing the same tweaking/restoring I/O mechanism: they need the I/O request to fully cover the main/OOB area. Let's make this code generic as sharing the code between two drivers is already a win. Maybe other ECC engine drivers will need it too. Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20200929230124.31491-2-miquel.raynal@bootlin.com

mtd: nand: Use the new generic ECC object

2020-09-28T13:59:48Z

Embed a generic NAND ECC high-level object in the nand_device structure to carry all the ECC engine configuration/data. Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20200827085208.16276-16-miquel.raynal@bootlin.com

mtd: nand: Create helpers to set/extract the ECC requirements

2020-09-28T13:59:48Z

Despite its current name, the eccreq field actually encodes both the NAND requirements and the final ECC configuration. That works fine when using on-die ECC since those 2 concepts match perfectly, but it starts being a problem as soon as we use on-host ECC engines, where we're not guaranteed to have a perfect match. Let's hide the ECC requirements access behind helpers so we can later split those 2 concepts. As the structures have not been clarified yet, these helpers access the same internal variable as nanddev_get_ecc_conf() for now. Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20200827085208.16276-14-miquel.raynal@bootlin.com

mtd: nand: Create a helper to extract the ECC configuration

2020-09-28T13:59:48Z

Despite its current name, the eccreq field actually encodes both the NAND requirements and the final ECC configuration. That works fine when using on-die ECC since those 2 concepts match perfectly, but it starts being a problem as soon as we use on-host ECC engines, where we're not guaranteed to have a perfect match. Let's hide the ECC configuration access behind a helper so we can later split those 2 concepts. Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20200827085208.16276-12-miquel.raynal@bootlin.com

mtd: nand: Introduce the ECC engine framework

2020-09-02T07:28:15Z

Create a generic ECC engine framework. This is a base to instantiate ECC engine objects. If we really want to be generic, bindings must evolve, so here is the new logic. The following three properties are mutually exclusive: - The nand-no-ecc-engine boolean property is set and there is no ECC engine to retrieve. - The nand-use-soft-ecc-engine boolean property is set and the core will force using the use of software correction. - There is a nand-ecc-engine property pointing at a node which will act as ECC engine. It the later case, the property may reference: - The NAND chip node itself (for the on-die ECC case). - The parent node if the NAND controller embeds an ECC engine. - Any other node being an external ECC controller as well. Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20200827085208.16276-9-miquel.raynal@bootlin.com