SMBus alert support. The SMBus alert protocol allows several SMBus
slave devices to share a single interrupt pin on the SMBus master,
while still allowing the master to know which slave triggered the
interrupt.
This is based on preliminary work by David Brownell. The key
difference between David's implementation and mine is that his was
part of i2c-core, while mine is split into a separate, standalone
module named i2c-smbus. The i2c-smbus module is meant to include
support for all SMBus extensions to the I2C protocol in the future.
The benefit of this approach is a zero cost for I2C bus segments which
do not need SMBus alert support. Where David's implementation
increased the size of struct i2c_adapter by 7% (40 bytes on i386),
mine doesn't touch it. Where David's implementation added over 150
lines of code to i2c-core (+10%), mine doesn't touch it. The only
change that touches all the users of the i2c subsystem is a new
callback in struct i2c_driver (common to both implementations.) I seem
to remember Trent was worried about the footprint of David'd
implementation, hopefully mine addresses the issue.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Trent Piepho <tpiepho@freescale.com>
When the i2c-parport adapter is reponsible for powering devices, it
would seem reasonable to give them some time to settle before trying
to access them.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The description of the delay parameter is incomplete, it suggests that
there is a direct relation between the delay value and the bus
frequency. In fact, due to additional delays in the i2c bitbanging
code, the i2c clock is always much slower.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Till Harbaum <Till@Harbaum.org>
The id_table field of the struct pci_driver is constant in <linux/pci.h>
so it is worth to make initialization data also constant.
The semantic match that finds this kind of pattern is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@r@
disable decl_init,const_decl_init;
identifier I1, I2, x;
@@
struct I1 {
...
const struct I2 *x;
...
};
@s@
identifier r.I1, y;
identifier r.x, E;
@@
struct I1 y = {
.x = E,
};
@c@
identifier r.I2;
identifier s.E;
@@
const struct I2 E[] = ... ;
@depends on !c@
identifier r.I2;
identifier s.E;
@@
+ const
struct I2 E[] = ...;
// </smpl>
Signed-off-by: Márton Németh <nm127@freemail.hu>
Cc: Julia Lawall <julia@diku.dk>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Since the drivers data now contains the i2c adapter structure, we can
pass around the drivers data between internal functions (which is what
they want) rather than using the i2c adapter structure and having an
additional pointer dereference each time.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
clk_set_rate() is not supposed to be used to turn clocks on and off.
That's what clk_enable/clk_disable is for.
Acked-by: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The functionality bit vector is always returned as a little-endian
32-bit number by the device, so it must be byte-swapped to the host
endianness.
On the other hand, the delay value is handled by the USB stack, so no
byte swapping is needed on our side.
This fixes bug #15105:
http://bugzilla.kernel.org/show_bug.cgi?id=15105
Reported-by: Jens Richter <jens@richter-stutensee.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Jens Richter <jens@richter-stutensee.de>
Cc: Till Harbaum <till@harbaum.org>
Cc: stable@kernel.org
accordingly adapt order of release_mem_region and release_mem_region on
remove.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Richard Zhao <linuxzsc@gmail.com>
Cc: Darius Augulis <augulis.darius@gmail.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: linux-i2c@vger.kernel.org
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
After generating the stop bit by changing MSTA from 1 to 0,
the i2c_imx->stopped was immediatly set to 1. The second test
on i2c_imx->stopped then is correct and the controller never
waits if the bus is busy. This patch corrects this.
On mx31moboard, stop bit was not generated on single write transfers.
This was kept unnoticed as other transfers are made afterwards that
help the write recipient to resynchronize.
Thanks to Philippe and Michael for the debugging.
Signed-off-by: Valentin Longchamp <valentin.longchamp@epfl.ch>
Signed-off by: Philippe Rétornaz <philippe.retornaz@epfl.ch>
Reported-by: Michael Bonani <michael.bonani@epfl.ch>
Acked-by; Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
dev_dbg outputs dev_name, which is released with device_unregister. This bug
resulted in output like this:
i2c Xy2�0: adapter [SMBus I801 adapter at 1880] unregistered
The right output would be:
i2c i2c-0: adapter [SMBus I801 adapter at 1880] unregistered
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Unexpected signals can disturb the bus-handling and lock it up. Don't use
interruptible in 'wait_event_*' and 'wake_*' as in commits
dc1972d027 (for cpm),
1ab082d7cb (for mpc),
b7af349b17 (for omap).
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Remove the following sparse warnings (see "make C=1"):
* drivers/i2c/busses/i2c-ali1563.c:91:3: warning: do-while statement
is not a compound statement
* drivers/i2c/busses/i2c-ali1563.c:161:3: warning: do-while statement
is not a compound statement
Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
With `while (timeout++ < MAX_TIMEOUT)' timeout reaches MAX_TIMEOUT + 1
after the loop. This is probably unlikely to produce a problem.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The C99 specification states in section 6.11.5:
The placement of a storage-class specifier other than at the beginning
of the declaration specifiers in a declaration is an obsolescent
feature.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Current OMAP3 I2C driver code does not follow the correct sequence for soft
reset. Due to this, lock up issues are reported during timeout/error cases.
This patch fixes above issue by disabling I2C controller as per OMAP3430 TRM
for soft reset. As per TRM, I2C controller needs to be disabled as a first
step during soft reset.
Here is correct soft reset sequence:
a. Ensure that the module is disabled
(clear the I2Ci.I2C_CON[15] I2C_EN bit to 0).
b. Set the I2Ci.I2C_SYSC[1] SRST bit to 1.
c. Enable the module by setting I2Ci.I2C_CON[15] I2C_EN bit to 1.
d. Check the I2Ci.I2C_SYSS[0] RDONE bit until it is set to 1 to
indicate the software reset is complete.
Tested on Zoom2, Zoom3, 3430SDP and 3630SDP
Signed-off-by: Manjunatha GK <manjugk@ti.com>
Signed-off-by: George, Harith<harith@ti.com>
Acked-by: Varadarajan, Charu Latha<charu@ti.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Commit ef871432... (i2c-omap: OMAP3: PM: (re)init for every transfer
to support off-mode) introduced a change which make the dev->iestate
contents be written to the OMAP_I2C_IE_REG every time omap_i2c_unidle
is called. Previously, the state was only written if it wasn't equal
to zero.
In omap_i2c_probe, omap_i2c_unidle() is called prior to omap_i2c_init(),
in which case dev->iestate has not yet been initialized and will be set
to zero. Having this value written to the registers causes deadlock
while booting.
As such, this change restores the original functionality.
Signed-off-by: Cory Maccarrone <darkstar6262@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Calculation of the CLKDIV speed setting should be done using base 10 math
rather than base 2. We also avoid exceeding the spec due to integer
truncation and a 50% duty cycle.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Struct dev_pm_ops is not configured in current i2c bus type. i2c drivers
only depends on suspend/resume entries in struct dev_pm_ops are not
informed of PM suspend and resume events by i2c framework.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Struct i2c_client_address_data only contains one field at this point,
which makes its usefulness questionable. Get rid of it and pass simple
address lists around instead.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
The "kind" parameter always has value -1, and nobody is using it any
longer, so we can remove it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
* 'acpica' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
ACPICA: Update version to 20091112.
ACPICA: Add additional module-level code support
ACPICA: Deploy new create integer interface where appropriate
ACPICA: New internal utility function to create Integer objects
ACPICA: Add repair for predefined methods that must return sorted lists
ACPICA: Fix possible fault if return Package objects contain NULL elements
ACPICA: Add post-order callback to acpi_walk_namespace
ACPICA: Change package length error message to an info message
ACPICA: Reduce severity of predefined repair messages, Warning to Info
ACPICA: Update version to 20091013
ACPICA: Fix possible memory leak for Scope ASL operator
ACPICA: Remove possibility of executing _REG methods twice
ACPICA: Add repair for bad _MAT buffers
ACPICA: Add repair for bad _BIF/_BIX packages
Because of OMAP off-mode, powerdomain can go off when I2C is idle.
Save enough state, and do a re-init for each transfer.
Additional save/restore state added by Jagadeesh Bhaskar Pakaravoor
(SYSC_REG) and Aaro Koskinen (wakeup sources.)
Also, The OMAP3430 TRM states:
"During active mode (I2Ci.I2C_CON[15] I2C_EN bit is set to 1), make no
changes to the I2Ci.I2C_SCLL and I2Ci.I2C_SCLH registers. Changes may
result in unpredictable behavior."
Hence, the I2C_EN bit should be clearer when modifying these
registers. Please note that clearing the entire I2C_CON register to
disable the I2C module is safe, because the I2C_CON register is
re-configured for each transfer.
Signed-off-by: Jouni Hogander <jouni.hogander@nokia.com>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Cc: Jagadeesh Bhaskar Pakaravoor <j-pakaravoor@ti.com>
Cc: Aaro Koskinen <aaro.koskinen@nokia.com>
Cc: Jon Hunter <jon-hunter@ti.com>
Cc: Hu Tao <taohu@motorola.com>
Cc: Xiaolong Chen <A21785@motorola.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
In the case of no-ACKs, we don't want to see dev_err() messages in the
console, because some utilities like i2c-tools are capable of printing
decorated console output. This patch will ease such situations.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
* ABRT_MASTER_DIS: Fix a typo.
* i2c_dw_handle_tx_abort: Return an appropriate error number
depending on abort_source.
* i2c_dw_xfer: Add a missing abort_source initialization.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Suppose TX_ABRT occurs in the middle of processing i2c_msg msgs[], and
a STOP condition has already been generated on the bus. In this case,
subsequent i2c_dw_xfer_msg() might initiate a new and unnecessary I2C
transaction, which we'd have to avoid.
Furthermore, anytime TX_ABRT is set, the contents of tx/rx buffers are
flushed, so we don't have to process RX_FULL and TX_EMPTY.
Disable interrupts, and skip them.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Current error handling procedures are not good in two respects:
* Forgot to mark dev->cmd_complete as "completed" on errors
Once an I2C transaction is initiated, wait_for_completion_
interruptible_timeout() waits for dev->cmd_complete to be completed.
We have to take care of it whenever an error is detected, otherwise
we will have a needless HZ timeout.
* Forgot to disable interrupts
In the previous patch, interrupt mask operations have been changed.
We don't disable interrupts at the end of the interrupt handler any
more, and try to keep RX_FULL (and TX_EMPTY if required) enabled
during the transaction so that we can send longer data than the size
of Tx/Rx FIFO.
If an error is detected, we need to disable interrupts before
quitting current transaction.
We can work around above points using dev->msg_err effectively.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Currently we disable TX_EMPTY interrupt when buf_len is zero, but this
is wrong. (buf_len == 0) means that all transmit data in the current
i2c_msg message has been sent out, but that doesn't necessarily mean
all i2c_msg messages have been processed.
TX_EMPTY interrupt is used as the driving force of DW I2C transactions,
so we need to keep it enabled as long as i2c_msg messages are available.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Currently we process the first i2c_dw_xfer_msg() in i2c_dw_xfer(),
but in this case there is a possibility to be interrupted by certain
interrupts. As described before in this patchset, we need to keep
providing new transmit data within a given time period, otherwise Tx
FIFO underrun takes place and STOP condition will be generated on the
bus, even if we have more bytes to be written.
In order to exclude all such possibilities, change TX_EMPTY interrupt
usage as below:
* DW_IC_INTR_DEFAULT_MASK: Define a default interrupt mask set, and
put TX_EMPTY there.
* i2c_dw_xfer_init: Enable DW_IC_INTR_DEFAULT_MASK prior to initiating
a new I2C transaction. The first TX_EMPTY will be triggered shortly.
With the help of it, we can make the first call to i2c_dw_xfer_msg()
in the interrupt handler.
* i2c_dw_xfer_msg: Fixup intr_mask operation accordingly. Make sure
that TX_EMPTY operations need to be reversed.
* request_irq: Set IRQF_DISABLED so that we could load transmit data
into Tx FIFO without being distracted by other interrupts.
* Remove i2c_dw_xfer_msg() in i2c_dw_xfer().
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
I2c_dw_xfer_msg() also has the same target address inconsistency check,
and furthermore it checks across all i2c_msg messages, while
i2c_dw_read() walks through i2c_msg messages only with_ I2C_M_RD flag.
That is, target address check in i2c_dw_read() is redundant and useless.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Set proper I2C_FUNC_SMBUS_* bits so that the driver could be used with
some utilities requiring SMBus functionalities, such as i2c-tools.
Note that DW I2C core doesn't support I2C_FUNC_SMBUS_QUICK, as it's not
capable of zero-length data transactions.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
As the driver and hardware always process the given data in parallel,
then it would be better to initialize tx_limit, rx_limit and rx_valid
variables just prior to being used.
This will help us to send / receive as much data as possible.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
While we have a local variable "buf_len" for dev->tx_buf_len, we don't
have such local variable for dev->tx_buf pointer. While "buf_len" is
restored at first then updated when we start processing a new i2c_msg
(determined by STATUS_WRITE_IN_PROGRESS flag), ->tx_buf is different.
Such inconsistency makes the code slightly hard to follow.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
We have some steps at the top of i2c_dw_xfer_msg() to set up a slave
address and enable DW I2C core. And it's executed only when we don't
have STATUS_WRITE_IN_PROGRESS.
But we need to make sure that STATUS_WRITE_IN_PROGRESS only indicates
that we have a pending i2c_msg to process. In other words, even if
STATUS_WRITE_IN_PROGRESS is not set, that doesn't mean we're at initial
state in the I2C transaction.
Since i2c_dw_xfer_msg() will be invoked again and again during a
transaction, those init steps have a possibility to be re-processed
needlessly. For example, this issue easily takes place when processing
a combined transaction with a certain condition (the number of tx bytes
in the first i2c_msg, equals to the Tx FIFO depth).
Consequently we should not use STATUS_WRITE_IN_PROGRESS to determine
where we're at in an I2C transaction. It would be better to separate
those initialization steps from i2c_dw_xfer_msg().
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Enable RX_FULL interrupt mask by default, and hook it in the interrupt
handler. If requested amount of rx data (defined by IC_RX_TL) is not
available, we don't have to process i2c_dw_read().
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
As a hardware feature, DW I2C core generates a STOP condition whenever
the Tx FIFO becomes empty (strictly speaking, whenever the last byte in
the Tx FIFO is sent out), even if we have more bytes to be written.
In other words, we must never make "Tx FIFO underrun" happen during
a transaction, except for the last byte. For the safety's sake, we'd
make TX_EMPTY interrupt get triggered every time one byte is processed.
The Rx FIFO threshold needs to be set as well.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Jean Delvare