Commit Graph

1095 Commits

Author SHA1 Message Date
Zhangfei Gao
0c43ea544c i2c: Document the message size limit
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>
2010-03-02 12:23:49 +01:00
Jean Delvare
eec74a257f i2c-algo-pca: Drop duplicate variable
Thanks to -Wshadow.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
2010-03-02 12:23:47 +01:00
Mark Brown
6de468ae2d i2c: Hook up runtime PM support
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>
2010-03-02 12:23:46 +01:00
Jean Delvare
927ab2f807 i2c-parport-light: Add SMBus alert support
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>
2010-03-02 12:23:45 +01:00
Jean Delvare
3585925448 i2c-parport: Add SMBus alert support
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>
2010-03-02 12:23:44 +01:00
Jean Delvare
e2ca307439 i2c: Separate Kconfig option for i2c-smbus
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>
2010-03-02 12:23:43 +01:00
Jean Delvare
b5527a7766 i2c: Add SMBus alert support
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>
2010-03-02 12:23:42 +01:00
Jean Delvare
6d376fcc28 i2c-parport: Give powered devices some time to settle
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>
2010-03-02 12:23:41 +01:00
Jean Delvare
c05d490234 i2c-tiny-usb: Fix a comment on bus frequency
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>
2010-03-02 12:23:40 +01:00
Seth Heasley
393764340b i2c-i801: Add Intel Cougar Point device IDs
Add the Intel Cougar Point (PCH) SMBus controller device IDs.

Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-03-02 12:23:39 +01:00
Márton Németh
4111ecd217 i2c: Make PCI device ids constant
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>
2010-03-02 12:23:37 +01:00
Linus Torvalds
ac0f6f927d Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (100 commits)
  ARM: Eliminate decompressor -Dstatic= PIC hack
  ARM: 5958/1: ARM: U300: fix inverted clk round rate
  ARM: 5956/1: misplaced parentheses
  ARM: 5955/1: ep93xx: move timer defines into core.c and document
  ARM: 5954/1: ep93xx: move gpio interrupt support to gpio.c
  ARM: 5953/1: ep93xx: fix broken build of clock.c
  ARM: 5952/1: ARM: MM: Add ARM_L1_CACHE_SHIFT_6 for handle inside each ARCH Kconfig
  ARM: 5949/1: NUC900 add gpio virtual memory map
  ARM: 5948/1: Enable timer0 to time4 clock support for nuc910
  ARM: 5940/2: ARM: MMCI: remove custom DBG macro and printk
  ARM: make_coherent(): fix problems with highpte, part 2
  MM: Pass a PTE pointer to update_mmu_cache() rather than the PTE itself
  ARM: 5945/1: ep93xx: include correct irq.h in core.c
  ARM: 5933/1: amba-pl011: support hardware flow control
  ARM: 5930/1: Add PKMAP area description to memory.txt.
  ARM: 5929/1: Add checks to detect overlap of memory regions.
  ARM: 5928/1: Change type of VMALLOC_END to unsigned long.
  ARM: 5927/1: Make delimiters of DMA area globally visibly.
  ARM: 5926/1: Add "Virtual kernel memory..." printout.
  ARM: 5920/1: OMAP4: Enable L2 Cache
  ...

Fix up trivial conflict in arch/arm/mach-mx25/clock.c
2010-03-01 09:15:15 -08:00
Rade Bozic
85660f43a3 MIPS: I2C: Add driver for Cavium OCTEON I2C ports.
Signed-off-by: Rade Bozic <rade.bozic.ext@nsn.com>
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: Michael Lawnick <michael.lawnick.ext@nsn.com>
To: linux-mips@linux-mips.org
To: linux-i2c@vger.kernel.org
To: ben-linux@fluff.org
To: khali@linux-fr.org
Cc: rade.bozic.ext@nsn.com
Cc: Michael Lawnick <michael.lawnick.ext@nsn.com>
Patchwork: http://patchwork.linux-mips.org/patch/890/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-02-27 12:53:05 +01:00
Russell King
eed18b5fa4 ARM: PNX4008: use msecs_to_jiffies() rather than open-coding it
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-12 17:32:42 +00:00
Russell King
7e20c83720 ARM: PNX4008: i2c-pnx makes no use of asm/uaccess.h nor asm/irq.h
Remove unnecessary includes

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-12 17:32:42 +00:00
Russell King
4be53dbe74 ARM: PNX4008: i2c-pnx: don't split messages across several lines
It makes them harder to grep for.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-12 17:32:42 +00:00
Russell King
81d6724a56 ARM: PNX4008: Use i2c driver data for passing between internal functions
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>
2010-02-12 17:32:41 +00:00
Russell King
9d7f73632c ARM: PNX4008: move i2c_adapter structure inside the drivers private data
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-12 17:32:41 +00:00
Russell King
44c5d73918 ARM: PNX4008: kzalloc i2c drivers internal data
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-12 17:32:40 +00:00
Russell King
88d968b22f ARM: PNX4008: Make ioaddr 'void __iomem *' rather than 'u32'
This avoids unnecessary casting.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-12 17:32:40 +00:00
Russell King
6fff3da998 ARM: PNX4008: get i2c clock rate from clk API
Acked-by: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-12 17:32:39 +00:00
Russell King
ebdbbf2003 ARM: PNX4008: convert i2c-pnx to use clk API enable/disable calls
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>
2010-02-12 17:32:39 +00:00
Russell King
0321cb83e1 ARM: PNX4008: move i2c clock start/stop into driver
Acked-by: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-12 17:32:39 +00:00
Russell King
a0dcf19f59 ARM: PNX4008: move i2c suspend/resume callbacks into driver
Acked-by: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-12 17:32:38 +00:00
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 #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
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