Merge tag 'char-misc-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the large set of char/misc driver patches for 5.8-rc1

  Included in here are:

   - habanalabs driver updates, loads

   - mhi bus driver updates

   - extcon driver updates

   - clk driver updates (approved by the clock maintainer)

   - firmware driver updates

   - fpga driver updates

   - gnss driver updates

   - coresight driver updates

   - interconnect driver updates

   - parport driver updates (it's still alive!)

   - nvmem driver updates

   - soundwire driver updates

   - visorbus driver updates

   - w1 driver updates

   - various misc driver updates

  In short, loads of different driver subsystem updates along with the
  drivers as well.

  All have been in linux-next for a while with no reported issues"

* tag 'char-misc-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (233 commits)
  habanalabs: correctly cast u64 to void*
  habanalabs: initialize variable to default value
  extcon: arizona: Fix runtime PM imbalance on error
  extcon: max14577: Add proper dt-compatible strings
  extcon: adc-jack: Fix an error handling path in 'adc_jack_probe()'
  extcon: remove redundant assignment to variable idx
  w1: omap-hdq: print dev_err if irq flags are not cleared
  w1: omap-hdq: fix interrupt handling which did show spurious timeouts
  w1: omap-hdq: fix return value to be -1 if there is a timeout
  w1: omap-hdq: cleanup to add missing newline for some dev_dbg
  /dev/mem: Revoke mappings when a driver claims the region
  misc: xilinx-sdfec: convert get_user_pages() --> pin_user_pages()
  misc: xilinx-sdfec: cleanup return value in xsdfec_table_write()
  misc: xilinx-sdfec: improve get_user_pages_fast() error handling
  nvmem: qfprom: remove incorrect write support
  habanalabs: handle MMU cache invalidation timeout
  habanalabs: don't allow hard reset with open processes
  habanalabs: GAUDI does not support soft-reset
  habanalabs: add print for soft reset due to event
  habanalabs: improve MMU cache invalidation code
  ...

2 files changed, 89 insertions, 1 deletions

diff --git a/Documentation/trace/coresight/coresight-ect.rst b/Documentation/trace/coresight/coresight-ect.rst
index a93e52abcf46..a68732c5c6d6 100644
--- a/Documentation/trace/coresight/coresight-ect.rst
+++ b/Documentation/trace/coresight/coresight-ect.rst
@@ -73,7 +73,7 @@ capable of generating or using trigger signals.::
 
   >$ ls /sys/bus/coresight/devices/etm0/cti_cpu0
   channels  ctmid  enable  nr_trigger_cons mgmt  power powered  regs
-  subsystem triggers0 triggers1  uevent
+  connections subsystem triggers0 triggers1  uevent
 
 *Key file items are:-*
    * ``enable``: enables/disables the CTI. Read to determine current state.
@@ -89,6 +89,9 @@ capable of generating or using trigger signals.::
    * ``channels``: Contains the channel API - CTI main programming interface.
    * ``regs``: Gives access to the raw programmable CTI regs.
    * ``mgmt``: the standard CoreSight management registers.
+   * ``connections``: Links to connected *CoreSight* devices. The number of
+     links can be 0 to ``nr_trigger_cons``. Actual number given by ``nr_links``
+     in this directory.
 
 
 triggers<N> directories
diff --git a/Documentation/trace/coresight/coresight.rst b/Documentation/trace/coresight/coresight.rst
index 108600ee1e12..0b73acb44efa 100644
--- a/Documentation/trace/coresight/coresight.rst
+++ b/Documentation/trace/coresight/coresight.rst
@@ -241,6 +241,91 @@ to the newer scheme, to give a confirmation that what you see on your
 system is not unexpected. One must use the "names" as they appear on
 the system under specified locations.
 
+Topology Representation
+-----------------------
+
+Each CoreSight component has a ``connections`` directory which will contain
+links to other CoreSight components. This allows the user to explore the trace
+topology and for larger systems, determine the most appropriate sink for a
+given source. The connection information can also be used to establish
+which CTI devices are connected to a given component. This directory contains a
+``nr_links`` attribute detailing the number of links in the directory.
+
+For an ETM source, in this case ``etm0`` on a Juno platform, a typical
+arrangement will be::
+
+  linaro-developer:~# ls - l /sys/bus/coresight/devices/etm0/connections
+  <file details>  cti_cpu0 -> ../../../23020000.cti/cti_cpu0
+  <file details>  nr_links
+  <file details>  out:0 -> ../../../230c0000.funnel/funnel2
+
+Following the out port to ``funnel2``::
+
+  linaro-developer:~# ls -l /sys/bus/coresight/devices/funnel2/connections
+  <file details> in:0 -> ../../../23040000.etm/etm0
+  <file details> in:1 -> ../../../23140000.etm/etm3
+  <file details> in:2 -> ../../../23240000.etm/etm4
+  <file details> in:3 -> ../../../23340000.etm/etm5
+  <file details> nr_links
+  <file details> out:0 -> ../../../20040000.funnel/funnel0
+
+And again to ``funnel0``::
+
+  linaro-developer:~# ls -l /sys/bus/coresight/devices/funnel0/connections
+  <file details> in:0 -> ../../../220c0000.funnel/funnel1
+  <file details> in:1 -> ../../../230c0000.funnel/funnel2
+  <file details> nr_links
+  <file details> out:0 -> ../../../20010000.etf/tmc_etf0
+
+Finding the first sink ``tmc_etf0``. This can be used to collect data
+as a sink, or as a link to propagate further along the chain::
+
+  linaro-developer:~# ls -l /sys/bus/coresight/devices/tmc_etf0/connections
+  <file details> cti_sys0 -> ../../../20020000.cti/cti_sys0
+  <file details> in:0 -> ../../../20040000.funnel/funnel0
+  <file details> nr_links
+  <file details> out:0 -> ../../../20150000.funnel/funnel4
+
+via ``funnel4``::
+
+  linaro-developer:~# ls -l /sys/bus/coresight/devices/funnel4/connections
+  <file details> in:0 -> ../../../20010000.etf/tmc_etf0
+  <file details> in:1 -> ../../../20140000.etf/tmc_etf1
+  <file details> nr_links
+  <file details> out:0 -> ../../../20120000.replicator/replicator0
+
+and a ``replicator0``::
+
+  linaro-developer:~# ls -l /sys/bus/coresight/devices/replicator0/connections
+  <file details> in:0 -> ../../../20150000.funnel/funnel4
+  <file details> nr_links
+  <file details> out:0 -> ../../../20030000.tpiu/tpiu0
+  <file details> out:1 -> ../../../20070000.etr/tmc_etr0
+
+Arriving at the final sink in the chain, ``tmc_etr0``::
+
+  linaro-developer:~# ls -l /sys/bus/coresight/devices/tmc_etr0/connections
+  <file details> cti_sys0 -> ../../../20020000.cti/cti_sys0
+  <file details> in:0 -> ../../../20120000.replicator/replicator0
+  <file details> nr_links
+
+As described below, when using sysfs it is sufficient to enable a sink and
+a source for successful trace. The framework will correctly enable all
+intermediate links as required.
+
+Note: ``cti_sys0`` appears in two of the connections lists above.
+CTIs can connect to multiple devices and are arranged in a star topology
+via the CTM. See (:doc:`coresight-ect`) [#fourth]_ for further details.
+Looking at this device we see 4 connections::
+
+  linaro-developer:~# ls -l /sys/bus/coresight/devices/cti_sys0/connections
+  <file details> nr_links
+  <file details> stm0 -> ../../../20100000.stm/stm0
+  <file details> tmc_etf0 -> ../../../20010000.etf/tmc_etf0
+  <file details> tmc_etr0 -> ../../../20070000.etr/tmc_etr0
+  <file details> tpiu0 -> ../../../20030000.tpiu/tpiu0
+
+
 How to use the tracer modules
 -----------------------------