linux.git/drivers/i2c, branch v4.7-rc2

i2c: dev: use after free in detach

2016-05-28T15:37:42+00:00

The call to put_i2c_dev() frees "i2c_dev" so there is a use after
free when we call cdev_del(&i2c_dev->cdev).

Fixes: d6760b14d4a1 ('i2c: dev: switch from register_chrdev to cdev API')
Signed-off-by: Dan Carpenter 
Signed-off-by: Wolfram Sang

i2c: dev: don't start function name with 'return'

2016-05-27T11:13:01+00:00

I stumbled multiple times over 'return_i2c_dev', especially before the
actual 'return res'. It makes the code hard to read, so reanme the
function to 'put_i2c_dev' which also better matches 'get_free_i2c_dev'.

Signed-off-by: Wolfram Sang

i2c: dev: switch from register_chrdev to cdev API

2016-05-26T19:18:57+00:00

i2c-dev had never moved away from the older register_chrdev interface to
implement its char device registration. The register_chrdev API has the
limitation of enabling only up to 256 i2c-dev busses to exist.

Large platforms with lots of i2c devices (i.e. pluggable transceivers)
with dedicated busses may have to exceed that limit.
In particular, there are also platforms making use of the i2c bus
multiplexing API, which instantiates a virtual bus for each possible
multiplexed selection.

This patch removes the register_chrdev usage and replaces it with the
less old cdev API, which takes away the 256 i2c-dev bus limitation.
It should not have any other impact for i2c bus drivers or user space.

This patch has been tested on qemu x86 and qemu powerpc platforms with
the aid of a module which adds and removes 5000 virtual i2c busses, as
well as validated on an existing powerpc hardware platform which makes
use of the i2c bus multiplexing API.
i2c-dev busses with device minor numbers larger than 256 have also been
validated to work with the existing i2c-tools.

Signed-off-by: Erico Nunes 
[wsa: kept includes sorted]
Signed-off-by: Wolfram Sang

i2c: xlr: rename ARCH_TANGOX to ARCH_TANGO

2016-05-26T19:18:56+00:00

The ARCH name was changed during the review process of the mach, and
this driver was forgotten to be converted. Fix it now.
http://article.gmane.org/gmane.linux.ports.arm.kernel/456331

Signed-off-by: Marc Gonzalez 
[wsa: updated commit message slightly]
Signed-off-by: Wolfram Sang

i2c: at91: change log when dma configuration fails

2016-05-26T18:54:19+00:00

When the DMA configuration fails, there is a log reporting that we can't
use DMA and indicating the error number. When booting the kernel, it is
annoying to see this error number. Moreover, people can think something
is going wrong. It is not the case, it means that DMA can't be used but
it doesn't prevent to use i2c.

Signed-off-by: Ludovic Desroches 
Signed-off-by: Wolfram Sang

i2c: rcar: should depend on HAS_DMA

2016-05-26T18:51:59+00:00

If NO_DMA=y:

    drivers/built-in.o: In function `rcar_i2c_dma_unmap':
    i2c-rcar.c:(.text+0x6f06c6): undefined reference to `bad_dma_ops'
    drivers/built-in.o: In function `rcar_i2c_dma':
    i2c-rcar.c:(.text+0x6f07e2): undefined reference to `bad_dma_ops'
    i2c-rcar.c:(.text+0x6f0838): undefined reference to `bad_dma_ops'

Add a dependency on HAS_DMA to fix this.

Signed-off-by: Geert Uytterhoeven 
Acked-by: Niklas Söderlund 
Signed-off-by: Wolfram Sang

i2c: rcar: use dma_request_chan()

2016-05-26T18:43:06+00:00

New drivers should not use dma_request_slave_channel_reason() but
dma_request_chan(). The former is a macro to the later so this change do
not effect the driver in any way.

Reported-by: Arnd Bergmann 
Signed-off-by: Niklas Söderlund 
Signed-off-by: Wolfram Sang

Merge branch 'i2c/for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

2016-05-20T00:48:12+00:00

Pull i2c updates from Wolfram Sang:

 - Peter Rosin did some major rework on the locking of i2c muxes by
   seperating parent-locked muxes and mux-locked muxes.

   This avoids deadlocks/workarounds when the mux itself needs i2c
   commands for muxing.  And as a side-effect, other workarounds in the
   media layer could be eliminated.  Also, Peter stepped up as the i2c
   mux maintainer and will keep an eye on these changes.

 - major updates to the octeon driver

 - add a helper to the core to generate the address+rw_bit octal and
   make drivers use it

 - quite a bunch of driver updates

* 'i2c/for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (84 commits)
  i2c: rcar: add DMA support
  i2c: st: Implement bus clear
  i2c: only check scl functions when using generic recovery
  i2c: algo-bit: declare i2c_bit_quirk_no_clk_stretch as static
  i2c: tegra: disable clock before returning error
  [media] rtl2832: regmap is aware of lockdep, drop local locking hack
  [media] rtl2832_sdr: get rid of empty regmap wrappers
  [media] rtl2832: change the i2c gate to be mux-locked
  [media] si2168: change the i2c gate to be mux-locked
  iio: imu: inv_mpu6050: change the i2c gate to be mux-locked
  i2c: mux: document i2c muxes and elaborate on parent-/mux-locked muxes
  i2c: mux: relax locking of the top i2c adapter during mux-locked muxing
  i2c: muxes always lock the parent adapter
  i2c: allow adapter drivers to override the adapter locking
  i2c: uniphier: add "\n" at the end of error log
  i2c: mv64xxx: remove CONFIG_HAVE_CLK conditionals
  i2c: mv64xxx: use clk_{prepare_enable,disable_unprepare}
  i2c: mv64xxx: handle probe deferral for the clock
  i2c: mv64xxx: enable the driver on ARCH_MVEBU
  i2c: octeon: Add workaround for broken irqs on CN3860
  ...

i2c: rcar: add DMA support

2016-05-15T06:52:49+00:00

Make it possible to transfer i2c message buffers via DMA.
Start/Stop/Sending_Slave_Address and some data is still handled using
the old state machine, it is sending the bulk of the data that is done
via DMA.

The first byte of a transmission and the last two bytes of reception are
sent/received using PIO. This is needed for the HW to have access to the
first byte before DMA transmit and to be able to set the STOP condition
for DMA reception.

Signed-off-by: Niklas Söderlund 
Acked-by: Rob Herring 
Tested-by: Wolfram Sang 
[wsa: fixed a checkpatch warning]
Signed-off-by: Wolfram Sang

i2c: st: Implement bus clear

2016-05-13T10:40:15+00:00

>From I2C specifications:
      http://www.nxp.com/documents/user_manual/UM10204.pdf

Chapter 3.1.16, when the i2c device held the SDA line low, the master
should send 9 clocks pulses to try to recover.

Signed-off-by: Frederic Pillon 
Signed-off-by: Peter Griffin 
Signed-off-by: Wolfram Sang