Commit Graph

1071 Commits

Author SHA1 Message Date
Jean Delvare
1c010ff891 i2c-tiny-usb: Fix on big-endian systems
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 :
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
2010-02-05 17:48:13 +01:00
Uwe Kleine-König
4927fbf11d i2c: imx: call ioremap only after request_mem_region
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>
2010-01-24 15:25:57 +00:00
Valentin Longchamp
a1ee06b729 i2c: mxc: let time to generate stop bit
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>
2010-01-24 15:25:56 +00:00
Thadeu Lima de Souza Cascardo
c556752109 i2c: Do not use device name after device_unregister
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>
2010-01-16 20:43:13 +01:00
Wolfram Sang
22f8b2695e i2c/pca: Don't use *_interruptible
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>
2010-01-16 20:43:13 +01:00
Márton Németh
7d53e79f9e i2c-ali1563: Remove sparse warnings
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>
2010-01-16 20:43:13 +01:00
Roel Kluin
b6a3195070 i2c: Test off by one in {piix4,vt596}_transaction()
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>
2010-01-16 20:43:12 +01:00
Tobias Klauser
0b2c368844 i2c-core: Storage class should be before const qualifier
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>
2010-01-16 20:43:12 +01:00
Manjunatha GK
57eb81b14e i2c-omap: OMAP3: Fix I2C lockup during timeout/error cases
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>
2009-12-24 01:30:54 +00:00
Cory Maccarrone
07ac31f6f4 i2c-omap: Don't write IE state in unidle if 0
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>
2009-12-24 01:26:06 +00:00
Sonic Zhang
ac07fb4dc1 i2c-bfin-twi: fix CLKDIV calculation
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>
2009-12-24 01:24:48 +00:00
Alexey Dobriyan
471452104b const: constify remaining dev_pm_ops
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:25 -08:00
sonic zhang
54067ee206 i2c-core: i2c bus should support PM entries in struct dev_pm_ops
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>
2009-12-14 21:17:30 +01:00
Jean Delvare
c3813d6af1 i2c: Get rid of struct i2c_client_address_data
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>
2009-12-14 21:17:25 +01:00
Jean Delvare
310ec79210 i2c: Drop the kind parameter from detect callbacks
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>
2009-12-14 21:17:23 +01:00
Linus Torvalds
3067e02f8f Merge branch 'acpica' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
* '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
2009-12-09 19:57:06 -08:00
Kevin Wells
155a49319f i2c-pnx: Map I2C adapter number to platform ID number
Map I2C adapter number to platform ID number

Signed-off-by: Kevin Wells <kevin.wells@nxp.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-12-09 00:19:13 +00:00
Rajendra Nayak
ef871432e1 i2c-omap: OMAP3: PM: (re)init for every transfer to support off-mode
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>
2009-12-09 00:19:13 +00:00
Shinya Kuribayashi
6d1ea0f6af i2c-designware: i2c_dw_handle_tx_abort: Use dev_dbg() for NOACK cases
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>
2009-12-09 00:19:13 +00:00
Shinya Kuribayashi
a0e06ea64c i2c-designware: Cosmetic cleanups
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-12-09 00:19:13 +00:00
Shinya Kuribayashi
ce6eb574a1 i2c-designware: Tx abort cleanups
* 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>
2009-12-09 00:19:13 +00:00
Shinya Kuribayashi
597fe310f1 i2c-designware: Skip RX_FULL and TX_EMPTY bits on tx abort errors
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>
2009-12-09 00:19:12 +00:00
Shinya Kuribayashi
8f588e40c7 i2c-designware: i2c_dw_xfer_msg: Fix error handling procedures
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>
2009-12-09 00:19:12 +00:00
Shinya Kuribayashi
69151e532c i2c-designware: Disable TX_EMPTY when all i2c_msg msgs has been processed
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>
2009-12-09 00:19:12 +00:00
Shinya Kuribayashi
201d6a70b7 i2c-designware: Process all i2c_msg messages in the interrupt handler
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>
2009-12-09 00:19:12 +00:00
Shinya Kuribayashi
41c4e35037 i2c-designware: i2c_dw_read: Remove redundant target address checker
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>
2009-12-09 00:19:12 +00:00
Shinya Kuribayashi
52d7e430cf i2c-designware: i2c_dw_func: Set I2C_FUNC_SMBUS_foo bits
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>
2009-12-09 00:19:12 +00:00
Shinya Kuribayashi
ae72222d03 i2c-designware: Initialize byte count variables just prior to being used
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>
2009-12-09 00:19:11 +00:00
Shinya Kuribayashi
26ea15b1f5 i2c-designware: i2c_dw_xfer_msg: Introduce a local "buf" pointer
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>
2009-12-09 00:19:11 +00:00
Shinya Kuribayashi
81e798b73a i2c-designware: Divide i2c_dw_xfer_msg into two functions
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>
2009-12-09 00:19:11 +00:00
Shinya Kuribayashi
21a89d4101 i2c-designware: Enable RX_FULL interrupt
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>
2009-12-09 00:19:11 +00:00
Shinya Kuribayashi
4cb6d1d6da i2c-designware: Set Tx/Rx FIFO threshold levels
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>
2009-12-09 00:19:11 +00:00
Shinya Kuribayashi
0774539948 i2c-designware: Process i2c_msg messages in the interrupt handler
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>
2009-12-09 00:19:11 +00:00
Shinya Kuribayashi
c70c5cd374 i2c-designware: i2c_dw_xfer_msg: Fix i2c_msg search bug
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>
2009-12-09 00:19:10 +00:00
Shinya Kuribayashi
d60c7e81dd i2c-designware: Improved _HCNT/_LCNT calculation
* 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>
2009-12-09 00:19:10 +00:00
Shinya Kuribayashi
6d2ea4875f i2c-designware: Remove an useless local variable "num"
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>
2009-12-09 00:19:10 +00:00
Shinya Kuribayashi
e77cf23251 i2c-designware: i2c_dw_xfer_msg: Use "struct dw_i2c_dev" pointer
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>
2009-12-09 00:19:10 +00:00
Shinya Kuribayashi
78839bd0f2 i2c-designware: i2c_dw_read: Use "struct dw_i2c_dev" pointer
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>
2009-12-09 00:19:10 +00:00
Shinya Kuribayashi
91b52caec0 i2c-designware: Use platform_get_irq helper
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>
2009-12-09 00:19:10 +00:00
Shinya Kuribayashi
e28000a38d i2c-designware: Don't use the IC_CLR_INTR register to clear interrupts
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>
2009-12-09 00:19:09 +00:00
Shinya Kuribayashi
ed5e1dd5f2 i2c-designware: Consolidate to use 32-bit word accesses
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>
2009-12-09 00:19:09 +00:00
Jean Delvare
38f41f282f i2c-stub: Allow user to disable some commands
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>
2009-12-06 17:06:29 +01:00
Jean Delvare
4710317891 i2c-stub: Implement I2C block support
This is required to test some drivers, for example at24.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:28 +01:00
Jean Delvare
69b0089a67 i2c: Refactor for_each callbacks
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>
2009-12-06 17:06:27 +01:00
Jean Delvare
7e2193a8f9 i2c-i801: Retry on lost arbitration
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>
2009-12-06 17:06:27 +01:00
Vincent Sanders
9669f54194 i2c: Remove big kernel lock from i2cdev_open
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>
2009-12-06 17:06:26 +01:00
Jean Delvare
ccfbbd082a i2c: Simplify i2c_detect_address
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>
2009-12-06 17:06:25 +01:00
Jean Delvare
c7b25a9e96 i2c: Drop probe, ignore and force module parameters
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>
2009-12-06 17:06:24 +01:00
Jean Delvare
abe38388e5 i2c: Add missing __devinit markers to old i2c adapter drivers
These _setup functions are called from _probe so they can be marked
__devinit.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:23 +01:00
Jean Delvare
da44bdeb95 i2c: Bus drivers don't have to support I2C_M_REV_DIR_ADDR
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>
2009-12-06 17:06:22 +01:00