Make sure we avoid a division-by-zero OOPS in case clock-frequency is
set too low in DT. Add missing '\n' while we are here.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Axel Lin <axel.lin@ingics.com>

This reverts commit 34cf2acdafaa31a13821e45de5ee896adcd307b1. 'ret' is
not set when bailing out. Also, there is a better place to check for 0.

Reported-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Make sure we don't OOPS in case clock-frequency is set to 0 in a DT. The
variable set here is later used as a divisor.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

sysfs attributes should use the same format for reads and writes,
rather than pretty-printing on read.

* Make the "cur_master" attribute read back as just the name of the
  master
* Expose the list of all masters as a read-only "available_masters"
  attribute, using space separators as in similar attributes of other
  devices

Also, spell out "cur_master" in full as "current_master".

Fixes: 50a5ba876908 ("i2c: mux: demux-pinctrl: add driver")
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Jan reported this:

===
After enabling CONFIG_I2C_DEBUG_CORE my system was broken
(no network, console login not possible). System log was
flooded with the this message:

 ...
[  608.052077] rtc-ds1307 0-0068: uevent
[  608.052500] rtc-ds1307 0-0068: uevent
[  608.052925] rtc-ds1307 0-0068: uevent
 ...

The culprit is the dev_dbg printk in the i2c uevent handler.
If this is activated (for instance by CONFIG_I2C_DEBUG_CORE)
it results in an endless loop with systemd-journald.

This happens if user-space scans the system log and reads the uevent
file to get information about a newly created device, which seems fair
use to me. Unfortunately reading the "uevent" file uses the same
function that runs for creating the uevent for a new device,
generating the next syslog entry.

Ideally user-space would implement a recursion detection and
after reading the same device file for the 1000th time call it a
day, but nevertheless I think we should avoid this problem by
removing the debug print completely or using another print variant.

The same problem seems to be reported here:
https://bugs.freedesktop.org/show_bug.cgi?id=76886
===

His patch converted the message to pr_debug, but I think the debug can
simply go. We have other means to see code paths these days. This
enables us to clean up the function some more while we are here.

Reported-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Tested-by: Jan Glauber <jglauber@cavium.com>

Pull i2c updates from Wolfram Sang:
 "Mostly usual driver updates and improvements.  The changelog should
  give an idea.  Standing out is the i2c-qup driver with lots of new
  capabilities and we also have now an i2c-demuxer.

  I'd especially like to welcome Peter Rosin as the i2c-mux maintainer.
  He has an interesting series for muxes in the queue and agreed to look
  after this part of the subsystem.  Thank you, Peter, and welcome
  again!

  The octeon changes were applied pretty recently before the merge
  window.  I am aware.  They are the first (and relatively simple)
  patches of a larger overhaul to this driver.  In case something goes
  wrong with them, they are easy to fix (or revert).  The advantage I
  see is that they are out of the way, and I can concentrate on the next
  block of patches.  I really would like to apply the overhaul in
  smaller batches to avoid regressions.  And waiting a cycle for the
  introductory patches seemed too much of a delay for me"

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (39 commits)
  i2c: octeon: Support I2C_M_RECV_LEN
  i2c: octeon: Cleanup resource allocation code
  i2c: octeon: Cleanup i2c-octeon driver
  MAINTAINERS: add Peter Rosin as i2c mux maintainer
  dt-bindings: i2c: Spelling s/propoerty/property/
  i2c: immediately mark ourselves as registered
  i2c: i801: sort IDs alphabetically
  MAINTAINERS: Mika and me are designated reviewers for I2C DESIGNWARE
  i2c: octeon: Cleanup kerneldoc comments
  i2c: do not use internal data from driver core
  i2c: cadence: Fix the kernel-doc warnings
  i2c: imx: remove extra spaces.
  i2c: rcar: don't open code of_device_get_match_data()
  i2c: qup: Fix fifo handling after adding V2 support
  i2c: xiic: Implement power management
  i2c: piix4: Pre-shift the port number
  i2c: piix4: Always use the same type for port
  i2c: piix4: Support alternative port selection register
  i2c: tegra: don't open code of_device_get_match_data()
  i2c: riic, sh_mobile, rcar: Use ARCH_RENESAS
  ...

If I2C_M_RECV_LEN is set consider the length byte.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Remove resource values from struct i2c_octeon and use
devm_ioremap_resource helper.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Cleanup only without functional change.

- removed DRV_VERSION
- defines: use defines instead of plain values,
  use BIT_ULL macro, add comments
- rename waitqueue return value to time_left
- sort local variables by length
- fix indentation and whitespace errors
- make function return void if the result is not used
  (octeon_i2c_stop, octeon_i2c_set_clock)
- remove debug code from octeon_i2c_stop
- renamed some functions for readability
- update copyright

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Mark the i2c bus as registered right after the the bus_register call,
not at the end of init. Otherwise, we can't register our own dummy
driver.

Reported-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fixes: 95026658c46ea2 ("i2c: do not use internal data from driver core")