This patch adds support for the Xilinx XPS IIC Bus Interface.
The driver uses the dynamic mode, supporting to put several
I2C messages in the FIFO to reduce the number of interrupts.
It has the same feature as ocores, it can be passed a list
of devices that will be added when the bus is probed.
Signed-off-by: Richard Röjfors <richard.rojfors@pelagicore.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
The current i2c-omap driver is set up for 32-bit registers, which
corresponds to most OMAP devices. However, OMAP730/850 based
devices use a 16-bit register size.
This change modifies the driver to perform a runtime CPU type check
to determine the register sizes, and uses a bit shift of either 1
or 2 bits to compute the proper register sizes for all registers.
Signed-off-by: Cory Maccarrone <darkstar6262@gmail.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
The start/stop condtions are set in different places repetedly in the i2c-pnx
driver. Beside in i2c_pnx_start and i2c_pnx_stop the start/stop bit are also
set during the transfer of a i2c message in the master_xmit/rcv calls. This is
wrong since we can't set the start/stop condition during the transaction of a
single message any way. As a matter of fact, the driver will sometimes set both
the start and the stop bits at one time. This can be easily reproduced by
sending a simple read request like e.g
struct i2c_msg msgs[] = {
{ addr, 0, 1, buf },
{ addr, I2C_M_RD, offset, buf }
};
While processing the first message the i2c_pnx_master_xmit will set both the
start_bit and the stop_bit, which will eventually confuse the slave.
Fixed by remove setting start/stop condition from the transmit routines.
Signed-off-by: Luotao Fu <l.fu@pengutronix.de>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
As I2C interrupts must be enabled for the MPC512x by the setup function
as well, "fsl,preserve-clocking" is handled in a slighly different way.
Also, the old settings are now reported calling dev_dbg(). For the
MPC512x the clock setup function of the MPC52xx can be re-used.
Furthermore, the Kconfig help has been updated and corrected.
Signed-off-by: Wolfgang Grandegger <wg@denx.de>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
To prepare support for the MPC512x processors from Freescale the
"setclock" initialization functions have been renamed to "setup"
because I2C interrupts must be enabled for the MPC512x by this
function as well.
Signed-off-by: Wolfgang Grandegger <wg@denx.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
"__devinit[data]" has not yet been used for all initialization functions
and data. To avoid truncating lines, the struct "mpc_i2c_match_data" has
been renamed to "mpc_i2c_data", which is even the better name.
Signed-off-by: Wolfgang Grandegger <wg@denx.de>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Having a pointer to the probe function is unnecessary when using
platform_driver_probe and yields a section mismatch warning after
removing the white list entry "*driver" for
{ .data$, .data.rel$ } -> { .init.* } mismatches in modpost.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This adds support for ST-Ericsson's I2C block found
in Ux500 and Nomadik 8815 platforms.
Signed-off-by: srinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Andrea Gallo <andrea.gallo@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Reviewed-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
LPC_SCH is selected by GPI_SCH and I2C_ISCH, even when PCI is not
enabled, but LPC_SCH depends on PCI, so make GPI_SCH and I2C_ISCH
also depend on PCI.
Those 2 selects also need to select what LPC_SCH selects,
since kconfig does not follow selects.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Denis Turischev <denis@compulab.co.il>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Convert i2c-isch to platform_device for the lpc mfd core to add it at probe
time.
Signed-off-by: Denis Turischev <denis@compulab.co.il>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Rename for_each_bit to for_each_set_bit in the kernel source tree. To
permit for_each_clear_bit(), should that ever be added.
The patch includes a macro to map the old for_each_bit() onto the new
for_each_set_bit(). This is a (very) temporary thing to ease the migration.
[akpm@linux-foundation.org: add temporary for_each_bit()]
Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
i2c_master_send & i2c_master_recv do not support more than 64 kb
transfer, since msg.len is u16.
Signed-off-by: Zhangfei Gao <zgao6@marvell.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Allow I2C drivers to make use of the runtime PM framework by adding
bus implementations of the runtime PM operations. These simply
immediately suspend when the device is idle. The runtime PM framework
provides drivers with off the shelf refcounts for enables and sysfs
control for managing runtime suspend from userspace so is useful even
without meaningful input from the bus.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Add support for the SMBus alert mechanism to the i2c-parport-light
driver. The ADM1032 evaluation board at least is properly wired for
this.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Trent Piepho <tpiepho@freescale.com>
Add support for the SMBus alert mechanism to the i2c-parport driver.
The ADM1032 evaluation board at least is properly wired for this.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Trent Piepho <tpiepho@freescale.com>
Having a separate Kconfig option for i2c-smbus makes it possible to
build that support as a module even when i2c-core itself is built-in.
Bus drivers which implement SMBus alert should select this option, so
in most cases this option is hidden and the user doesn't have to care
about it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Trent Piepho <tpiepho@freescale.com>
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>
In particular, several occurances of funny versions of 'success',
'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address',
'beginning', 'desirable', 'separate' and 'necessary' are fixed.
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Joe Perches <joe@perches.com>
Cc: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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>
Symptom:
--------
When we're going to send/receive the longer size of data than the Tx
FIFO length, the I2C transaction will be divided into several separated
transactions, limited by the Tx FIFO length.
Details:
--------
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.
Then, once a new transmit data is written to the Tx FIFO, DW I2C core
will initiate a new transaction, which leads to another START condition.
This explains how the transaction in question goes, and implies that
current tasklet-based dw_i2c_pump_msg() strategy couldn't meet the
timing constraint required for avoiding Tx FIFO underrun.
To avoid this scenario, we must keep providing new transmit data within
a given time period. In case of Fast-mode + 32-byte Tx FIFO, for
instance, it takes about 22.5[us] to process single byte, and 720[us] in
total.
This patch removes the existing tasklet-based "pump" system, and move
its jobs into the interrupt handler.
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>
In case a work-in-progress i2c_msg has more bytes to be written, we
need to set STATUS_WRITE_IN_PROGRESS and exit from the msg_write_idx-
searching loop. Otherwise, we will overtake the current msg_write_idx
without waiting for its transmission to be processed.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
* Calculate with accurate conditional expressions from DW manuals.
* Round ic_clk by adding 0.5 as it's important at high ic_clk rate.
* Take into account "tHD;STA" issue for _HCNT calculation.
* Take into account "tf" for _LCNT calculation.
* Add "cond" and "offset" fot further correction requirements.
For _HCNT calculation, there's one issue needs to be carefully
considered; DesignWare I2C core doesn't seem to have solid strategy
to meet the tHD;STA timing spec. If you configure _HCNT based on the
tHIGH timing spec, it easily results in violation of the tHD;STA spec.
After many trials, we came to the conclusion that the tHD;STA period
is proportional to (_HCNT + 3). For the safety's sake, this should be
selected by default.
As for _LCNT calculation, DW I2C core has one characteristic behavior;
he starts counting the SCL CNTs for the LOW period of the SCL clock
(tLOW) as soon as it pulls the SCL line. At that time, he doesn't take
into account the fall time of SCL signal (tf), IOW, he starts counting
CNTs without confirming the SCL input voltage has dropped to below VIL.
This characteristics becomes a problem on some platforms where tf is
considerably long, and results in violation of the tLOW timing spec.
To make the driver configurable as much as possible for various cases,
we'd have separated arguments "tf" and "offset", and for safety default
values should be 0.3 us and 0, respectively.
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 couldn't know the original intent for this variable, but at this
point it's useless.
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 don't have to use "struct i2c_adapter" pointer here.
Let's use a local "struct dw_i2c_dev" pointer, instead.
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 don't have to use "struct i2c_adapter" pointer here.
Let's use a local "struct dw_i2c_dev" pointer, instead.
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're strongly discouraged from using the IC_CLR_INTR register because
it clears all software-clearable interrupts asserted at the moment.
stat = readl(IC_INTR_STAT);
:
: <=== Interrupts asserted during this period will be lost
:
readl(IC_CLR_INTR);
Instead, use the separately-prepared IC_CLR_* registers.
At the same time, this patch adds all remaining interrupt definitions
available in the DesignWare I2C hardware.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This driver looks originally meant for armel machines where readw()/
writew() works perfectly fine with this hardware. But that doens't
work for big-endian systems.
This patch converts all 8/16-bit-aware usages to 32-bit variants.
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>
Add a module parameter to override the functionality bitfield. This
lets the user disable some commands. This can be used to force a chip
driver to take different code paths.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Functions i2c_do_add_adapter() and __attach_adapter() do essentially
the same thing, differing only in how the parameters are passed. Same
for i2c_do_add_adapter() and __detach_adapter(). Introduce wrappers to
normalize the parameters, so that we do not have to duplicate the
code.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
The Intel 82801 is sometimes used on systems with a BMC connected. The
BMC can access the SMBus, resulting in lost arbitration for the 82801.
We should let i2c-core retry transactions for us in this case.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The BKL is held over a kmalloc so cannot protect anything beyond that.
The two calls before the kmalloc have their own locking.
Improve device open function by removing the now unnecessary ret variable
Signed-off-by: Vincent Sanders <vince@simtec.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The kind parameter of i2c_detect_address() always has value -1, so we
can get rid of it.
Next step is to update all i2c detect callback functions to get rid of
this now useless parameter.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The legacy probe and force module parameters are obsolete now, the
same can be achieved using the new_device sysfs interface, which is
both more flexible and cheaper (it is implemented by i2c-core rather
than replicated in every driver module.)
The legacy ignore module parameters can be dropped as well. Ignoring
can be done by instantiating a "dummy" device at the problematic
address.
This is the first step of a huge cleanup to i2c-core's i2c_detect
function, i2c.h's I2C_CLIENT_INSMOD* macros, and all drivers that made
use of them.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
I2C bus drivers don't have to support I2C_M_REV_DIR_ADDR. It is a
deviation from the I2C specification, which only makes sense to
implement when really needed.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Low priority thread holding the i2c bus mutex could block higher
priority threads to access the bus resulting in unacceptable
latencies. Change the mutex type to rt_mutex preventing priority
inversion.
Tested-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@nokia.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Superseded by tdfxfb. I2C/DDC support used to live in a separate
driver but this caused driver conflicts.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Krzysztof Helt <krzysztof.h1@wp.pl>
We no longer need to write the adapter name to a temporary buffer.
We can write it directly to the i2c_adapter's name field. This is
more efficient.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Michel Daenzer <michel@daenzer.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Include the i2c_adapter in struct pmac_i2c_bus. This avoids memory
fragmentation and allows for several code cleanups.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Michel Daenzer <michel@daenzer.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Log errors when they happen, otherwise we have no idea what went
wrong.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Michel Daenzer <michel@daenzer.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
I wanted to add some error logging to the i2c-powermac driver, but
found that it was very difficult due to the way the
i2c_powermac_smbus_xfer function is organized. Refactor the code in
this function so that each low-level function is only called once.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Michel Daenzer <michel@daenzer.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
The i2c-powermac driver doesn't support arbitrary multi-message I2C
transactions, only SMBus ones. Make it clear by returning an error if
a multi-message I2C transaction is attempted. This is better than only
processing the first message, because most callers won't recover from
the short transaction. Anyone wishing to issue multi-message
transactions should use the SMBus API instead of the raw I2C API.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Michel Daenzer <michel@daenzer.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
As i2c/chips is deprecated, move ds1682 to a more apropriate location.
Build tested.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
at24: Use timeout also for read
i2c: Fix userspace_device list corruption
MAINTAINERS: Add missing i2c files
i2c/tsl2550: Fix lux value in extended mode
According to the TAOS Application Note 'Controlling a Backlight with
the TSL2550 Ambient Light Sensor' (page 14), the actual lux value in
extended mode should be obtained multiplying the calculated lux value
by 5.
Signed-off-by: Michele Jr De Candia <michele.decandia@valueteam.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The existing interface only has a pre-order callback. This change
adds an additional parameter for a post-order callback which will
be more useful for bus scans. ACPICA BZ 779.
Also update the external calls to acpi_walk_namespace.
http://www.acpica.org/bugzilla/show_bug.cgi?id=779
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
