kernel/include/linux/mtd/rawnand.h, branch linux-5.1.y

mtd: rawnand: remove ->legacy.erase and single_erase()

2019-02-05T15:56:11Z

Now that the last user of this hook, denali.c, stopped using it, we can remove the erase hook from nand_legacy. I squashed single_erase() because only the difference between single_erase() and nand_erase_op() is the number of bit shifts. The status/ret conversion in nand_erase_nand() is unneeded since commit eb94555e9e97 ("mtd: nand: use usual return values for the ->erase() hook"). Cleaned it up now. Signed-off-by: Masahiro Yamada Reviewed-by: Boris Brezillon Signed-off-by: Miquel Raynal

mtd: rawnand: Simplify the locking

2019-02-05T14:39:40Z

nand_get_device() was complex for apparently no good reason. Let's replace this locking scheme with 2 mutexes: one attached to the controller and another one attached to the chip. Every time the core calls nand_get_device(), it will first lock the chip and if the chip is not suspended, will then lock the controller. nand_release_device() will release both lock in the reverse order. nand_get_device() can sleep, just like the previous implementation, which means you should never call that from an atomic context. We also get rid of - the chip->state field, since all it was used for was flagging the chip as suspended. We replace it by a field called chip->suspended and directly set it from nand_suspend/resume() - the controller->wq and controller->active fields which are no longer needed since the new controller->lock (now a mutex) guarantees that all operations are serialized at the controller level - panic_nand_get_device() which would anyway be a no-op. Talking about panic write, I keep thinking the rawnand implementation is unsafe because there's not negotiation with the controller to know when it's actually done with it's previous operation. I don't intend to fix that here, but that's probably something we should look at, or maybe we should consider dropping the ->_panic_write() implementation Last important change to mention: we now return -EBUSY when someone tries to access a device that as been suspended, and propagate this error to the upper layer. Signed-off-by: Boris Brezillon Signed-off-by: Miquel Raynal

mtd: rawnand: Deprecate the dummy_controller field

2018-12-07T09:58:11Z

We try to force NAND controller drivers to properly separate the NAND controller object from the NAND chip one, so let's deprecate the dummy controller object embedded in nand_chip to encourage them to create their own instance. Signed-off-by: Boris Brezillon Signed-off-by: Miquel Raynal

mtd: rawnand: Move ->setup_data_interface() to nand_controller_ops

2018-12-07T09:38:27Z

->setup_data_interface() is a controller specific method and should thus be placed in nand_controller_ops. In order to make that work with controllers that support keeping pre-configured timings we need to add a new NAND_KEEP_TIMINGS flag to inform the core it should skip the timings selection step. Signed-off-by: Boris Brezillon Tested-by: Janusz Krzysztofik Signed-off-by: Miquel Raynal

mtd: rawnand: Move the ->exec_op() method to nand_controller_ops

2018-12-07T09:38:27Z

->exec_op() is a controller method and has nothing to do in the nand_chip struct. Let's move it to the nand_controller_ops struct and adjust the core and drivers accordingly. Signed-off-by: Boris Brezillon Tested-by: Janusz Krzysztofik Signed-off-by: Miquel Raynal

mtd: rawnand: Deprecate the ->select_chip() hook

2018-12-07T09:38:27Z

Now that the CS line to be selected is passed to ->exec_op() and stored in chip->cur_cs and after patching all drivers implementing ->exec_op() to stop implementing this method, we can deprecate it by moving it to the nand_legacy structure. Signed-off-by: Boris Brezillon Tested-by: Janusz Krzysztofik Signed-off-by: Miquel Raynal

mtd: rawnand: Pass the CS line to be selected in struct nand_operation

2018-12-07T09:38:25Z

In order to deprecate the ->select_chip hook we need to pass the CS line a NAND operations are targeting. This is done through the addition of a cs field to the nand_operation struct. We also need to keep track of the currently selected target to properly initialize op->cs, hence the ->cur_cs field addition to the nand_chip struct. Note that op->cs is not assigned in nand_exec_op() because we might rework the way we execute NAND operations in the future (adopt a queuing mechanism instead of the serialization we have right now). Signed-off-by: Boris Brezillon Tested-by: Janusz Krzysztofik Signed-off-by: Miquel Raynal

mtd: rawnand: Add nand_[de]select_target() helpers

2018-12-07T09:38:25Z

Add a wrapper to prevent drivers and core code from directly calling the ->select_chip hook which we are about to deprecate. Signed-off-by: Boris Brezillon Tested-by: Janusz Krzysztofik Signed-off-by: Miquel Raynal

mtd: rawnand: Remove unused NAND_CONTROLLER_ALLOC flag

2018-12-07T09:38:24Z

Looks like NAND_CONTROLLER_ALLOC has been introduced a long time ago back when the dummy nand_hw_ctrl object was dynamically allocated instead of being embedded in nand_chip. We can safely get rid of this unused flag. Signed-off-by: Boris Brezillon Tested-by: Janusz Krzysztofik Signed-off-by: Miquel Raynal

mtd: rawnand: Move nand_exec_op() to internal.h

2018-12-07T09:38:24Z

nand_exec_op() is only used by core code (nand_xxx.c files). Let's move this inline function in drivers/mtd/nand/raw/internals.h. Signed-off-by: Boris Brezillon Tested-by: Janusz Krzysztofik Signed-off-by: Miquel Raynal