The margin debugfs node controls the "Enable Margin Test" field of the
lane margining operations. This field selects between either low or high
voltage margin values for voltage margin test or left or right timing
margin values for timing margin test.

According to the USB4 specification, whether or not the "Enable Margin
Test" control applies, depends on the values of the "Independent
High/Low Voltage Margin" or "Independent Left/Right Timing Margin"
capability fields for voltage and timing margin tests respectively. The
pre-existing condition enabled the debugfs node also in the case where
both low/high or left/right margins are returned, which is incorrect.
This change only enables the debugfs node in question, if the specific
required capability values are met.

Signed-off-by: Aapo Vienamo <aapo.vienamo@linux.intel.com>
Fixes: d0f1e0c2a699 ("thunderbolt: Add support for receiver lane margining")
Cc: stable@vger.kernel.org
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Intel pre-USB4 routers only have ROUTER_CS_0 up to ROUTER_CS_4 and it
immediately follows the TMU router registers. Correct this accordingly.

Reported-by: Rajaram Regupathy <rajaram.regupathy@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

The dentry returned by debugfs_lookup() needs to be released by calling
dput() which is missing in margining_port_remove(). Fix this by calling
debugfs_lookup_and_remove() that combines both and avoids the memory leak.

Fixes: d0f1e0c2a699 ("thunderbolt: Add support for receiver lane margining")
Cc: stable@vger.kernel.org
Signed-off-by: Yaxiong Tian <tianyaxiong@kylinos.cn>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

For USB4 v2 routers, the PCIe adapter capability length is longer.
Display the correct capability length in the debugfs register dump.

Signed-off-by: Gil Fine <gil.fine@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

For USB4 v2 routers, the DisplayPort IN adapter capability length is
longer. Display the correct capability length in the debugfs register
dump.

Signed-off-by: Gil Fine <gil.fine@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

For USB4 v2 routers, the adapters's TMU capability has two additional
double words. Include them in the debugfs register dump.

Signed-off-by: Gil Fine <gil.fine@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

This allows us to disable all CL states temporarily when running lane
margining and then return back the previously enabled states.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

There really don't belong to switch.c so move them into their own file.
As we do this rename the functions to match the conventions used
elsewhere in the driver.

No functional changes.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Memory for the usb4->margining needs to be relased for the upstream port
of the router as well, even though the debugfs directory gets released
with the router device removal. Fix this.

Fixes: d0f1e0c2a699 ("thunderbolt: Add support for receiver lane margining")
Cc: stable@vger.kernel.org
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

When DisplayPort bandwidth allocation mode is supported by the DP IN
adapter it has an extra double word in the adapter config space. Include
this in the debugfs register dump.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>