| #
294674 |
|
24-Jan-2016 |
ian |
MFC r289727:
Add FDT compatibility to the icee driver.
The FDT bindings for eeprom parts don't include any metadata about the
device other than the part name encoded in the compatible property.
Instead, a driver is required to have a compiled-in table of information
about the various parts (page size, device capacity, addressing scheme). So
much for FDT being an abstract description of hardware characteristics, huh?
In addition to the FDT-specific changes, this also switches to using the
newer iicbus_transfer_excl() mechanism which holds bus ownership for the
duration of the transfer. Previously this code held the bus across all
the transfers needed to complete the user's IO request, which could be
up to 128KB of data which might occupy the bus for 10-20 seconds. Now the
bus will be released and re-aquired between every page-sized (8-256 byte)
transfer, making this driver a much nicer citizen on the i2c bus.
The hint-based configuration mechanism is still in place for non-FDT systems.
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| #
289666 |
|
20-Oct-2015 |
ian |
MFC r281828, r289083, r289084, r289091, r289093, r289095, r289097, r289098,
r289104, r289105, r289118: various i2c fixes...
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.
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.
Mostly rewrite the imx i2c driver. This started out as an attempt to fix
one specific problem: the driver didn't check for ACK/NAK after writing a
slave address byte to the bus, and some slaves signal that they are busy
(such as when completing an internal write to flash memory) by sending a
NAK in response to being addressed.
Use IIC_EBUSBSY and IIC_BUSERR status values consistantly across all drivers.
Make it clearer what each one means in the comments that define them.
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.
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.
Add a short name, IIC_INTRWAIT, for the common case (IIC_INTR | IIC_WAIT).
Replace a local sx lock that allowed only one client at a time to access
an eeprom device with iicbus_request/release_bus(), which achieves the
same effect and also keeps other i2c slave drivers from clashing on the bus.
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| #
181305 |
|
04-Aug-2008 |
jhb |
Lock the consumers of the iicbus(4) infrastructure:
- ad7418(4) uses an sx lock instead of a mtx since the iicbus(4) stuff it
calls can sleep (request_bus()). Also, I expanded the locking slightly
to serialize writes to data stored in the softc.
- Similarly, the icee(4) driver now uses an sx lock instead of a mutex.
I also removed the pointless OPENED flag and flags field from the softc.
- The locking for the ic(4) driver was a bit trickier:
- Add a mutex to the softc to protect softc data.
- The driver uses malloc'd buffers that are the size of the interface
MTU to send and receive packets. Previously, these were allocated
every time the interface was brought up and anytime the MTU was
changed, with various races that could result in memory leaks. I
changed this to be a bit simpler and more like other NIC drivers in
that we allocate buffers during attach for the default MTU size and
only reallocate them on MTU changes. The reallocation procedure
goes to some lengths with various flags to not replace either the
the receive or transmit buffers while the driver is busy receiving
or transmitting a packet.
- Store the device_t of the driver in the softc instead of detours into
new-bus using if_dunit from the ifnet and an even more bizarre detour
to get the softc instead of using if_softc.
- Drop the driver mutex when invoking netisr_dispatch() to pass the
packet up to IP.
- Use if_printf().
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