Commit graph

706 commits

Author SHA1 Message Date
Uwe Kleine-König
96eb7164e3 i2c/imx: don't add probe function to the driver struct
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>
2010-03-07 22:02:16 +00:00
srinidhi kasagar
3f9900f17c i2c: Add support for Ux500/Nomadik I2C controller
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>
2010-03-07 22:02:16 +00:00
Akinobu Mita
984b3f5746 bitops: rename for_each_bit() to for_each_set_bit()
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>
2010-03-06 11:26:23 -08:00
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
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
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
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
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