linux-stable.git/drivers/i2c/algos, branch linux-5.4.y

i2c: algo: pca: Reapply i2c bus settings after reset

2020-09-23T10:40:38+00:00

[ Upstream commit 0a355aeb24081e4538d4d424cd189f16c0bbd983 ]

If something goes wrong (such as the SCL being stuck low) then we need
to reset the PCA chip. The issue with this is that on reset we lose all
config settings and the chip ends up in a disabled state which results
in a lock up/high CPU usage. We need to re-apply any configuration that
had previously been set and re-enable the chip.

Signed-off-by: Evan Nimmo 
Reviewed-by: Chris Packham 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Wolfram Sang 
Signed-off-by: Sasha Levin

i2c: algo-pca: Add 0x78 as SCL stuck low status for PCA9665

2020-07-09T07:37:54+00:00

[ Upstream commit cd217f2300793a106b49c7dfcbfb26e348bc7593 ]

The PCA9665 datasheet says that I2CSTA = 78h indicates that SCL is stuck
low, this differs to the PCA9564 which uses 90h for this indication.
Treat either 0x78 or 0x90 as an indication that the SCL line is stuck.

Based on looking through the PCA9564 and PCA9665 datasheets this should
be safe for both chips. The PCA9564 should not return 0x78 for any valid
state and the PCA9665 should not return 0x90.

Fixes: eff9ec95efaa ("i2c-algo-pca: Add PCA9665 support")
Signed-off-by: Chris Packham 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Wolfram Sang 
Signed-off-by: Sasha Levin

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157

2019-05-30T18:26:37+00:00

Based on 3 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [kishon] [vijay] [abraham]
  [i] [kishon]@[ti] [com] this program is distributed in the hope that
  it will be useful but without any warranty without even the implied
  warranty of merchantability or fitness for a particular purpose see
  the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [graeme] [gregory]
  [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
  [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
  [hk] [hemahk]@[ti] [com] this program is distributed in the hope
  that it will be useful but without any warranty without even the
  implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Richard Fontana 
Reviewed-by: Kate Stewart 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman

treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21T08:50:46+00:00

Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

i2c: algo: bit: add flag to whitelist atomic transfers

2019-04-16T11:08:16+00:00

Use the new xfer_atomic callback to check a newly introduced flag to
whitelist atomic transfers. This will report configurations which
worked accidently.

Signed-off-by: Wolfram Sang 
Signed-off-by: Wolfram Sang

i2c: algo-bit: convert to SPDX header

2019-02-05T13:05:03+00:00

And use kernel style for the remaining comments in the header.

Signed-off-by: Wolfram Sang 
Reviewed-by: Simon Horman 
Signed-off-by: Wolfram Sang

i2c: algos: bit: make the error messages grepable

2018-08-30T21:11:42+00:00

Yep, I went looking for one of these, and I wasn't able to find it
easily.  That's worse than a line which is 82-chars long, IMHO.

Signed-off-by: Jan Kundrát 
Signed-off-by: Wolfram Sang

i2c: algos: bit: mention our experience about initial states

2018-06-29T06:19:51+00:00

So, if somebody wants to re-implement this in the future, we pinpoint to
a problem case.

Signed-off-by: Wolfram Sang 
Acked-by: Alex Deucher 
Signed-off-by: Wolfram Sang

Revert "i2c: algo-bit: init the bus to a known state"

2018-06-29T06:19:41+00:00

This reverts commit 3e5f06bed72fe72166a6778f630241a893f67799. As per
bugzilla #200045, this caused a regression. I don't really see a way to
fix it without having the hardware. So, revert the patch and I will fix
the issue I was seeing originally in the i2c-gpio driver itself. I
couldn't find new users of this algorithm since, so there should be no
one depending on the new behaviour.

Reported-by: Sergey Larin 
Fixes: 3e5f06bed72f ("i2c: algo-bit: init the bus to a known state")
Signed-off-by: Wolfram Sang 
Acked-by: Alex Deucher 
Tested-by: Sergey Larin 
Signed-off-by: Wolfram Sang 
Cc: stable@kernel.org

i2c: algos: make use of i2c_8bit_addr_from_msg

2018-05-29T18:30:06+00:00

Because it looks neater.

Signed-off-by: Peter Rosin 
Signed-off-by: Wolfram Sang