| #
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.
|
| #
276278 |
|
27-Dec-2014 |
ian |
MFC r274641, r274644, r274822, r276049:
Allow i2c bus speed to be configured via hints, FDT data, and sysctl.
Implement bus speed setting for OMAP4, AM335x, and imx5/6.
Fix the i2c bus speed divisors for TI OMAP4 and AM335x to give the
advertised 100, 400, and 1000 KHz speeds.
PR: 195009
|
| #
261410 |
|
02-Feb-2014 |
ian |
Follow r261352 by updating all drivers which are children of simplebus
to check the status property in their probe routines.
Simplebus used to only instantiate its children whose status="okay"
but that was improper behavior, fixed in r261352. Now that it doesn't
check anymore and probes all its children; the children all have to
do the check because really only the children know how to properly
interpret their status property strings.
Right now all existing drivers only understand "okay" versus something-
that's-not-okay, so they all use the new ofw_bus_status_okay() helper.
|