MFC r348355: revert r273728 and parts of r306589, iicbus no-stop by default feature

After r349227 the only consumer of that broken code is gone from this
branch.

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 r328307, r328311-r328312

r328307:
Fix a bug introduced with recursive bus ownership support in r321584.

The recursive ownership support added in r321584 was unconditionally in
effect all the time -- whenever a given i2c slave device instance tried to
lock the i2c bus for exclusive use when it already owned the bus, the call
returned immediately without waiting. However, many i2c slave drivers use
bus ownership to enforce that only a single thread at a time can be using
the slave device. The recursive locking changes broke this use case.

Now there is a new flag, IIC_RECURSIVE, which can be mixed in with the
other flags passed to iicbus_acquire_bus() to allow drivers to indicate
when recursive locking is desired. Using the flag implies that the driver
is managing concurrent access to the device by different threads in some way.

This immediately fixes all existing i2c slave drivers except for the two
i2c RTC drivers which use the recursive locking feature; those will be
fixed in a followup commit.

r328311 and r328312:
Follow changes in r328307 by using new IIC_RECURSIVE flag.

The driver now ensures only one thread at a time is running in the API
functions (clock_gettime() and clock_settime()) by specifically requesting
ownership of the i2c bus without using IIC_RECURSIVE, then it does all IO
using IIC_RECURSIVE so that each individual IO operation doesn't try to
re-acquire the bus.

The other IO done by the driver happens at attach or intr_config_hooks time,
when there can't be multiple threads running with the same device instance.
So, the IIC_RECURSIVE flag can be safely ORed into the wait flags for all IO
done by the driver, because it's all either done in a single-threaded
environment, or protected within a block bounded by explict
iicbus_acquire_bus() and iicbus_release_bus() calls.

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

MFC r321583, r321584:

Add a pair of convenience routines for doing simple "register" read/writes
on i2c devices, where the "register" can be any length.

Add support for tracking nested calls to iicbus_request/release_bus().
Usually it is sufficient to use iicbus_transfer_excl(), or one of the
higher-level convenience functions that use it, to reserve the bus for the
duration of each register access. Occasionally it is important that a
series of accesses or read-modify-write operations must be done without any
other intervening access to the device, to prevent corrupting state.

MFC r320460, r320461, r320462, r320463:

If an i2c transfer ends due to error, issue a stop on the bus even if the
nostop option is set, if a start was issued.

Add iic_recover_bus(), a helper function that can be used by any i2c driver
which is able to manipulate the clock and data lines directly.
When an i2c bus is hung by a slave device stuck in the middle of a
transaction that didn't complete properly, this function manipulates the
clock and data lines in a sequence known to reliably reset slave devices.
The most common cause of a hung i2c bus is a system reboot in the middle of
an i2c transfer (so it doesnt' happen often, but now there is a way other
than power cycling to recover from it).

Add bus recovery handling to the imx5/imx6 i2c driver.

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

Remove a couple of extra blank lines.

Add iicbus_transfer_excl(), a helper routine to do an i2c bus transaction
while holding exclusive ownership of the bus. This is the routine most
slave drivers should use unless they have a need to acquire and hold the
bus across a series of related operations that involves multiple transfers.

Fix more cases of iicbus-layer functions that must return IIC_Exxxx values.

Return only IIC_Exxxx status values from iicbus-layer functions. Most of
these functions are thin wrappers around calling the hardware-layer driver,
but some of them do sanity checks and return an error. Since the hardware
layer can only return IIC_Exxxxx status values, the iicbus helper functions
must also adhere to that, so that drivers at higher layers can assume that
any non-zero status value is an IIC_Exxxx value that provides details about
what happened at the hardware layer (sometimes those details are important
for certain slave drivers).

Add iic2errno(), a helper function to translate IIC_Exxxxx status values to
errno values that are at least vaguely equivelent. Also add a new status
value, IIC_ERESOURCE, to indicate a failure to acquire memory or other
required resources to complete a transaction.

The IIC_Exxxxxx values are supposed to communicate low-level details of the
i2c transaction status between the lowest-layer hardware driver and
higher-layer bus protocol and device drivers for slave devices on the bus.
Most of those slave drivers just return all status values from the lower
layers directly to their callers, resulting in crazy error reporting from a
user's point of view (things like timeouts being reported as "no such
process"). Now there's a helper function to make it easier to start
cleaning up all those drivers.

Bugfix: Exit the transfer loop if any read or write operation fails. Also,
perform a stop operation on the bus if there was an error, otherwise the
bus will remain hung forever. Consistantly use 'if (error != 0)' style in
the function.

Fix numerous issues in iic(4) and iicbus(4):
--Allow multiple open iic fds by storing addressing state in cdevpriv
--Fix, as much as possible, the baked-in race conditions in the iic
ioctl interface by requesting bus ownership on I2CSTART, releasing it on
I2CSTOP/I2CRSTCARD, and requiring bus ownership by the current cdevpriv
to use the I/O ioctls
--Reduce internal iic buffer size and remove 1K read/write limit by
iteratively calling iicbus_read/iicbus_write
--Eliminate dynamic allocation in I2CWRITE/I2CREAD
--Move handling of I2CRDWR to separate function and improve error handling
--Add new I2CSADDR ioctl to store address in current cdevpriv so that
I2CSTART is not needed for read(2)/write(2) to work
--Redesign iicbus_request_bus() and iicbus_release_bus():
--iicbus_request_bus() no longer falls through if the bus is already
owned by the requesting device. Multiple threads on the same device may
want exclusive access. Also, iicbus_release_bus() was never
device-recursive anyway.
--Previously, if IICBUS_CALLBACK failed in iicbus_release_bus(), but
the following iicbus_poll() call succeeded, IICBUS_CALLBACK would not be
issued again
--Do not hold iicbus mtx during IICBUS_CALLBACK call. There are
several drivers that may sleep in IICBUS_CALLBACK, if IIC_WAIT is passed.
--Do not loop in iicbus_request_bus if IICBUS_CALLBACK returns
EWOULDBLOCK; instead pass that to the caller so that it can retry if so
desired.

Differential Revision: https://reviews.freebsd.org/D2140
Reviewed by: imp, jhb, loos
Approved by: kib (mentor)

Add a method to iicbus to request IIC_M_NOSTOP behaviour for multibyte
transfers to be default. It simplifies porting code which assumes
such settings.

Discussed with: avg, llos, nwhitehorn
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Allow the i2c node requirements to be slightly relaxed.

These realtek switch PHYs speak a variant of i2c with some slightly
modified handling.

From the submitter, slightly modified now that some further digging
has been done:

The I2C framework makes a assumption that the read/not-write bit of the first
byte (the address) indicates whether reads or writes are to follow.

The RTL8366 family uses the bus: after sending the address+read/not-write byte,
two register address bytes are sent, then the 16-bit register value is sent
or received. While the register write access can be performed as a 4-byte
write, the read access requires the read bit to be set, but the first two bytes
for the register address then need to be transmitted.

This patch maintains the i2c protocol behaviour but allows it to be relaxed
(for these kinds of switch PHYs, and whatever else Realtek may do with this
almost-but-not-quite i2c bus) - by setting the "strict" hint to 0.
The "strict" hint defaults to 1.

Submitted by: Stefan Bethke <stb@lassitu.de>

Provide support for IIC_M_NOSTOP/IIC_M_NOSTART for bit-banging and
otherwise low-level controllers.

Reviewed by: thompsa

Revert changes accidentally committed as part of r209298.

Provide for multiple, cascaded PICs on PowerPC systems, and extend the
OFW interrupt map interface to also return the device's interrupt parent.

MFC after: 8.1-RELEASE

Handle errors from device_get_chidlren.
Free child list when there's more children than we expected.

Add locking to the core iicbus(4) drivers:
- Add an sx lock to the iic(4) driver to serialize open(), close(), read(),
and write and to protect sc_addr and sc_count in the softc.
- Use cdev->si_drv1 instead of using the minor number of the cdev to
lookup the softc via newbus in iic(4).
- Store the device_t in the softc to avoid a similar detour via minor
numbers in iic(4).
- Only add at most one instance of iic(4) and iicsmb(4) to each iicbus(4)
instance, and do it in the child driver.
- Add a mutex to the iicbus(4) softc to synchronize the request/release bus
stuff.
- Use __BUS_ACCESSOR() for IICBUS_ACCESSOR() instead of rolling our own.
- Add a mutex to the iicsmb(4) softc to protect softc state updated in the
interrupt handler.
- Remove Giant from all the smbus methods in iicsmb(4) now that all the
iicbus(4) backend is locked.

MFp4: Make iicbus_trasnfer_gen suitable for bridge drivers. Use it in the
bitbang bridge.

const poison

submitted by: john wehle

Allow iic bridges to support a generalized transfer, rather than
forcing all transfers to do the start read/write stop by hand. Some
smart bridges prefer this sort of operation, and this allows us to
support their features more easily. When bridges don't support it, we
fall back to using the old-style opertaions. Expand the ioctl
interface to expose this function. Unlike the old-style interface,
this interface is thread safe, even on old bridges.

Use __FBSDID().
Also some minor style cleanups.

Major rework of the iicbus/smbus framework:

- VIA chipset SMBus controllers added
- alpm driver updated
- Support for dynamic modules added
- bktr FreeBSD smbus updated but not tested
- cleanup

Remove unneeded #include <sys/kernel.h>

Remove ~25 unneeded #include <sys/conf.h>
Remove ~60 unneeded #include <sys/malloc.h>

Remove the 'ivars' arguement to device_add_child() and
device_add_child_ordered(). 'ivars' may now be set using the
device_set_ivars() function.

This makes it easier for us to change how arbitrary data structures are
associated with a device_t. Eventually we won't be modifying device_t
to add additional pointers for ivars, softc data etc.

Despite my best efforts I've probably forgotten something so let me know
if this breaks anything. I've been running with this change for months
and its been quite involved actually isolating all the changes from
the rest of the local changes in my tree.

Reviewed by: peter, dfr

Sync with RELENG_3.

$Id$ -> $FreeBSD$

Handle correctly iicbus request/release mechanism. Add iicbus allocation
to the general purpose i/o iic(4) driver.

Changed to use IICBUS_REPEATED_START

Submitted by: Changed to use IICBUS_REPEATED_START

Submitted by: Nicolas Souchu <nsouch@freebsd.org>

Updated to support bt848 driver and MSP3400 audio chip.
This adds changes made in 1.4.2.1 and 1.4.2.2 from RELENG_3

Change /dev/smb and /dev/iic interface to allow user programs to interact with
devices dynamically. That means,

+ only one /dev/iic or /dev/smb device for each smb/iic bus to access
+ I2C/SMB device address must be given to any ioctl
+ new devices may be plugged and accessed after boot, which was
impossible previously (device addresses were hardcoded into
the kernel)

Remove broken and useless intr interface.

Submitted by: Doug Rabson <dfr@nlsystems.com>
Amancio Hasty <hasty@rah.star-gate.com>

Avoid compile warnings.

iicbb is generic support for I2C bit-banging.

Other files: timeout management added to the I2C framework.

This commit was generated by cvs2svn to compensate for changes in r38774,
which included commits to RCS files with non-trunk default branches.

Submitted by: nsouch
Philips I2C bus generic support other new bus architecture.