MFC r335159, r344505-r344507, r344523, r344525-r344526, r344529, r344556,
r344606-r344612, r344614-r344616, r344681, r344684-r344686, r344728,
r344733-r344734, r344981

A large set of changes that collectively modernize the at45d and mx25l
(DataFlash and SpiFlash) drivers, add FDT support, and add geom_flashmap
support to them.

r335159 by manu:
mx25l: Add pnp info

r344505:
Add a functional detach() implementation to make module unloading possible.

r344506:
Add support for probing/attaching on FDT-based systems.

r344507:
Switch to using config_intrhook_oneshot(). That allows the error handling
in the delayed attach to use early returns, which allows reducing the level
of indentation. So all in all, what looks like a lot of changes is really
no change in behavior, mostly just moving whitespace around.

r344523:
Include the jedec "extended device information string" in the criteria used
to match a chip to our table of metadata describing the chips. At least one
new DataFlash chip has a 3-byte jedec ID identical to its predecessors and
differs only in the extended info, and it has different metadata requiring a
unique entry in the table. This paves the way for supporting such chips.

The metadata table now includes two new fields, extmask and extid. The two
bytes of extended info obtained from the chip are ANDed with extmask then
compared to extid, so it's possible to use only a subset of the extended
info in the matching.

We now always read 6 bytes of jedec ID info. Most chips don't return any
extended info, and the values read back for those two bytes may be
indeterminate, but such chips have extmask and extid values of 0x0000 in the
table, so the extid effectively doesn't participate in the matching on those
chips and it doesn't matter what they return in the extended info bytes.

r344525:
Add a metadata entry for the AT45DB641E chip. This chip has the same 3-byte
jedec ID as its older cousin the AT45DB642D, but uses a different page size.
The only way to distinguish between the two chips is that the 2D chip has
0 bytes of extended ID info and the new 1E has 1 byte of extended ID. The
actual value of the extended ID byte is all zeroes. In other words, it's
the presence of the extended info that identifies this chip. (Presumably
a future upgrade might define non-zero values for the extended ID byte.)

r344526:
Resolve a name conflict when both SpiFlash and DataFlash devices are present.

Both SpiFlash (mx25l) and DataFlash (at45d) drivers create a disk device
with a name of /dev/flash/spiN where N is the driver's unit number. If
both types of devices are present in the same system, this creates a fatal
conflict that prevents attachment of whichever device attaches second
(because mx25l0 and at45d0 both try to create a spi0).

This gives each type of device a unique name (mx25lN or at45dN respectively)
and also adds an alias of spiN for compatibility. When both device types
appear in the same system, only the first to attach gets the spiN alias.
When the second device attaches there is a non-fatal warning that the alias
can't be created, but both devices are still accessible via their primary
names (and there is no need for the spiN name to work for backwards
compatibility on such a system, because it has never been possible to use
the spiN names when both devices exist).

r344529:
Fix a paste-o that broke the build on all arches.

r344556:
Set maximum bus clock speed from hints when attaching hinted spibus(4) children.

Some devices (such as spigen(4)) document that this works, but it appears that the
code to implement it never got added.

r344606:
Add support for geom_flashmap by providing a getattr() for "SPI:device".

r344607:
Compile fdt_slicer and geom_flashmap when the at45d device is included.

r344608:
Update a comment to reflect reality; no functional changes.

r344609:
Make it possible to load fdt_slicer as a module (unloading works too fwiw).

r344610:
Add manpages for at45d(4) and mx25l(4).

r344611:
Add a module dependency on fdt_slicer.

r344612:
Add a module dependency on fdt_slicer. Also, move the PNP_INFO to its more
usual location, down near the DRIVER_MODULE() stuff.

r344614:
Rename some functions and variables to have shorter names, which allows
unwrapping multiple lines of code. Also, convert some short multiline
comments into single-line comments. Change old-school FALSE to false.

All in all, no functional changes, it's just more compact and readable.

r344615:
Child nodes with a compatible property are not slices, according to the
devicetree/bindings/mtd/partitions.txt document, so just ignore them.

r344616:
Add support to fdt_slicer for the new style partition data documented in
devicetree/bindings/mtd/partition.txt.

In the old style, all the children of the device node which did not have a
compatible property were the partitions. In the new style, there is a child
node of the device which has a compatible string of "fixed-partitions", and
its children are the individual partitions.

Also, support the read-only property by setting the corresponding slice flag.

r344681:
Build fdt support modules on systems that use fdt data.

kern.opts.mk sets make var OPT_FDT to a non-empty value if platform.h
contains OPT_FDT.

r344684:
Undo accidental part of r344681.

I think I must have accidentally mouse-click pasted while scrolling and
didn't notice it.

r344685:
Add required header file to SRCS.

r344686:
Add another required header file.

For some reason this seems to be required on aarch64, but I can build armv7
from clean without needing this in the list. (The file does get included,
so the mystery is why armv7 works.)

r344728:
Bugfix: use a dummy buffer for the inactive side of a transfer.

This is especially important for writes. SPI is inherently a bidirectional
bus; you receive data (even if it's garbage) while writing. We should not
receive that data into the same buffer we're writing to the device.

When reading it doesn't matter what we send to the device, but using the
dummy buffer for that as well is pleasingly symmetrical.

r344733:
Add some comments. Give #define'd names to some scattered numbers. Change
some #define'd names to be more descriptive. When reporting a post-write
compare failure, report the page number, not the byte address of the page.
The latter is the only functional change, it makes the number match the
words of the error message.

r344734:
Allow the sector size of the disk device to be configured using hints or
FDT data. The sector size must be a multiple of the device's page size.
If not configured, use the historical default of the device page size.

Setting the disk sector size to 512 or 4096 allows a variety of standard
filesystems to be used on the device. Of course you wouldn't want to be
writing frequently to a SPI flash chip like it was a disk drive, but for
data that gets written once (or rarely) and read often, using a standard
filesystem is a nice convenient thing.

r344981:
Give the mx25l device sole ownership of the name /dev/flash/spi* instead of
trying to use disk_add_alias() to make spi* an alias for mx25l*. It turns
out disk_add_alias() works for partitions, but not slices, and that's hard
to fix.

This change is, in effect, a partial revert of r344526.

The mips world relies on the existence of flashmap names formatted as
/dev/flash/spi0s.name, whereas pretty much nothing relies on at45d devices
using the /dev/spi* names (because until recently the at45d driver didn't
even work reliably). So this change makes mx25l devices the sole owner of
the /dev/flash/spi* namespace, which actually makes some sense because it is
a SpiFlash(tm) device, so flash/spi isn't a horrible name.

Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

MFC r310017, r310229, r312289, r327260, r329539, r329544-r329546, r329620,
r329729, r329911, r329999

r310017:
[spi] reformat message

This commit corrects print of nomatch (newline was too early)

Submitted by: Hiroki Mori <yamori813@yahoo.co.jp>
Reviewed by: ray, loos, mizhka
Differential Revision: https://reviews.freebsd.org/D8749

r310229:
ofw_spi: Parse property for the SPI mode and CS polarity.
As cs is stored in a uint32_t, use the last bit to store the
active high flag as it's unlikely that we will have that much CS.

Reviewed by: loos
Differential Revision: https://reviews.freebsd.org/D8614

r312289:
[spibus] small code refactoring

Merge 3 sequential printf calls into one.

Reported by: rpokala
Reviewed by: rpokala, adrian
Approved by: adrian (mentor)
Differential Revision: https://reviews.freebsd.org/D8795

r327260:
SPDX: fix wrong license ID tag in dev/spibus.

r329539:
Provide public declarations for ofw_spibus_driver and ofw_spibus_devclass
so other drivers can refer to them in DRIVER_MODULE() decls.

r329544:
Add modules/spi as a gathering point for SPI-related modules, analagous to
modules/i2c for i2c/iicbus modules. Build spibus as a module.

r329545:
Add ofw_bus_if.h to SRCS.

r329546:
Build at45d and mx25l SPI flash drivers as modules.

r329620:
Add missing MODULE_DEPENDS().

r329729:
Remove some files that snuck in via cut and paste.

Having these compiled into the module causes the kobj method descriptors
to be resolved incorrectly (by the compile-time linker instead of the
kernel linker), which then leads to hours of frustrating debugging.

r329911:
Add a functional detach() routine, to make things kldunload-friendly.

r329999:
Add a SPI driver for imx5 and imx6.

It can be compiled into the kernel with "device imx_spi" or loaded as a
module, which is also named "imx_spi".

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

undo previous commit - WIP was committed by accident.

Noticed by: bz

Only compile the FDT bits when we are using FDT.

Check the return value of config_intrhook_establish().

Remove duplicate const specifiers in many drivers (I hope I got all of
them, please let me know if not). Most of these are of the form:

static const struct bzzt_type {
[...list of members...]
} const bzzt_devs[] = {
[...list of initializers...]
};

The second const is unnecessary, as arrays cannot be modified anyway,
and if the elements are const, the whole thing is const automatically
(e.g. it is placed in .rodata).

I have verified this does not change the binary output of a full kernel
build (except for build timestamps embedded in the object files).

Reviewed by: yongari, marius
MFC after: 1 week

Revert r236529, re-enabling verification of the flashed content as
the underlying problem was dealt with in r237239 (in fact, disabling
verification also actually only made the problem less likely to occur).

Disable verification of the flashed content for now; for reasons unknown
it sometimes causes physwr to hang.

- Loop up to 3 seconds when waiting for a device to get ready. [1]
- Make the device description match the driver name.
- Identify the chip variant based on the JEDEC and use that information
to use the proper values for page count, offset and size instead of
hardcoding a AT45DB642x with 2^N byte page support disabled.
- Take advantage of bioq_takefirst().
- Given that CONTINUOUS_ARRAY_READ_HF (0x0b) command isn't even mentioned
in Atmel's DataFlash Application Note, as suggested by the previous
comment may not work on all all devices and actually doesn't properly
on at least AT45DB321D (JEDEC 0x1f2701), rewrite at45d_task() to use
CONTINUOUS_ARRAY_READ (0xe8) for reading instead. This rewrite is laid
out in a way allowing to easily add support for BIO_DELETE later on.
- Add support for reads and writes not starting on a page boundary.
- Verify the flash content after writing.
- Let at45d_task() gracefully handle errors on SPI transfers and the
device not becoming ready afterwards again. [1]
- Use DEVMETHOD_END. [1]
- Use NULL instead of 0 for pointers. [1]

Additional testing by: Ian Lepore

Submitted by: Ian Lepore [1]
MFC after: 1 week

- Remove nonexistent header file from includes list

Rename the kthread_xxx (e.g. kthread_create()) calls
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it turns out that most of these
calls actually end up being moved back to the thread version
when it's added. but we need to make this cosmetic change first.

I'd LOVE to do this rename in 7.0 so that we can eventually MFC the
new kthread_xxx() calls.

MFp4:
Preliminary support for Atmel AT45D series of DataFlash on the
SPI bus (ok, not really a hardware bus, but a logical
connection). This works only for the 8MB version of the part
due to hard coding. Both read and write are supported.